David Abram Essay Example | Topics and Well Written Essays - 1500 words

David Abram - Essay Example Abraham goes ahead to state that once human beings accept their bodies, they perforce recognize that they are also animals. Despite the uniqueness in mankind, its place is not above the animated world but instead in its midst. He also disagrees with the view that perception is the act of hearing, being aware or seeing something as perceived remains static, but instead its an interaction between one body and others or things, where there is a sympathetic or symbiosis relationship. He then discusses language which is rooted in the experience of senses. In a nutshell, Abram’s work presents a complex, detailed and good work that defines the existence of humanity. It throws a spanner on the complacency of the perceived truths and replaces them with thoughts that if they are not understood, they will remain open questions. He refers to it as a turning inside out resulting to loosening of the psyche from the confinement of human sphere. Simone de Beauvoir In her study, Ethics of Ambi guity, Simone de Beauvoir begins by presenting the characteristics of oppression, which includes; it removes the oppressed from community members believed to be in authority and can influence decisions and also aims towards the reduction of the oppressed to the status of an object. In his work, he believes that manipulation desire is one of the main ways through which oppression is exercised. Just like Sartre, she holds that the destruction of passion or desire will have a negative consequence for the creation of life and have a purpose in it.

Data and Assumption on New Technology Innovation Essay Example for Free

Data and Assumption on New Technology Innovation Essay Yesterday at the stroke of midnight a series of tragic events came to a closing when Othello, Venices most eminent and respected Moorish general, killed himself in his wifes bedchamber after smothering the young bellenone other than Venices coveted Desdemonawith a pillow. According to several witnesses of the bloody suicide, the mentally tormented general was under the notion that Desdemona had been illicitly tupping his first-in-command, Michael Cassio, a lie fed to him by the ironically misnamed Honest Iago. Iago, the villain responsible for the murder of his own wife as well as a Venetian gentleman, has been taken by Cyprian officials for questioning and possible torture. However, it is known that he orchestrated a plan to create conflict between General Othello and Lieutenant Cassio surrounding Desdemona that he hoped would result in the death of both Cassio and the lady. Witnesses to the blood bath describe the scene gravely and painfully. I walked into the room and there was Othello, with his wife Desdemona slain on the bed. It was really shocking. Her face was very pale, and though she was evidently dead, it seemed she was trying to say something, says Gratiano. Another witness describes Othellos suicide with great distress. He was very calm, but there was a wondrous rage in his face, like a monster. I had never seen him like that before. He took his sword and drove it into his chest before anyone could stop him. The only survivor of the discord is Lieutenant Cassio, who suffered a major injury in his leg from Iagos sword. When asked whether he was ever involved with lady Desdemona, Cassio responded, We were dear friends, and it pains me greatly that she is gone. But we never shared more than the touching of hands or a brief brush on the shoulder. As for the man who caused this, I will see to it that he pays for his cruelty with his own suffering. A funeral will be held in three days near the town square. Mourners are welcome, including former suitors of Desdemona. Michael Cassio asks that all that attend bring memorabilia of the lost ones such as locks of hair, clothing, letters, or embroidered handkerchiefs.

Billy Budd :: essays research papers

Billy Budd Main Characters Billy Budd- He is a bright-eyed, twenty-one year old forewoman of the British Fleet. An orphan, he is tall, athletic, friendly, innocent, and helpful. He is a loyal friend, and a fierce fighter. All the officers like him except for Claggart. Claggart- The Master-at-Arms that is envious and jealous of Billy Budd. He is out to make Billy's life miserable and is the cause of Billy Budd's execution. Captain Vere- The Honorable Edward Fairfax Vere is a bachelor of about forty. He has a nickname of "Starry Vere." Captain Vere is forced to execute Billy Budd though he knew of his innocence. But nevertheless Dansker- A veteran sailor who has taken a liking to Billy Budd. Tells Billy that Claggart doesn't like him. He is also one of the most important members of the crew. Chapters 1-7, Pages 1-27 The book starts out with the author remembering seeing a handsome man many years ago. He is reminded of this by the Handsome Sailor, Billy Budd. Billy is twenty- one, a foretopeman of the British fleet who impressed Lieutenant Ratcliffe of the H.M.S. Indomitable. Billy leaves his ship the Rights of Man, and joins the H.M.S. Indomitable. He is received well by the crew and they like him lots. An officer asks him about who his parents are and he reply's that he doesn't know. He was found in a basket hung on a man's door handle in Bristol. Billy seems to be practically perfect, but he does have one weakness. When he is strongly provoked, he is inclined to stutter, or may even become speechless. The author tells us of the uprisings in the British navy. It is later called the Great Mutiny. They sail for the Mediterranean and have an uneasiness about them as they watch for signs of trouble or discontent. Chapters 8-15, Pages 28-55 Billy had seen the gangway punishment, and was determined that he would always perform his duties well, and that his actions would never cause him to get yelled at. Though he had made that resolution, he was occasionally getting into slight trouble. He is confused by this, and goes to Dansker, who seems to have taken a liking to him. Billy asks him for his opinion, and he says that it is because Claggart doesn't like Billy. That with all evidence to the contrary, he despises him. The day after the discussion with Dansker, Billy spills soup on the freshly cleaned deck just as Claggart passes by him. Claggart notices that it was Billy that spilled the soup, and only taps him lightly with his rattan.

Robert Altmans The Long Goodbye As A Genre Revisionist Film Essay

"Robert Altman's The Long Goodbye attempts to do a very interesting thing. It tries to be all genre and no story†¦ It makes no serious effort to reproduce the Raymond Chandler detective novel†¦ it just takes all the characters out of that novel and lets them stew together in something that feels like a private-eye movie." ---ROGER EBERT (REVIEW) The period of American cinema between 1965 and 1975 produced many films that almost completely restructured classical Hollywood’s accepted genre conventions. A fine example of this would be Robert Altman's iconoclastic take on Raymond Chandler's Philip Marlowe in The Long Goodbye (1973), a detective film based on the final book in Chandler’s Philip Marlowe series. Altman, who is known for turning around traditional genre conventions, revises and reinvents the film-noir style made popular by Dick Powell in Murder, My Sweet (1944), Humphrey Bogart in The Big Sleep (1946), and Robert Montgomery in Lady in the Lake (1947). The actors and the films in the 1940’s film-noir period conformed to genre conventions, and it wasn’t until Robert Altman directed Elliot Gould’s Philip Marlowe in The Long Goodbye that the detective genre had changed. It is very interesting to note how the conventions of 1940’s hardboiled private eye fiction translate into the 1970’s. The low-rent drabness of the genre loses much of its allure. The dark shadows and long nights of urban Los Angeles become the bright lights and warm sunshine of Malibu beaches. The detective’s normally snappy dialogue turns into joking asides. Marlowe’s hardboiled narration becomes the self-conscious mutterings of a lonely man talking to himself. The romantic myth of a man set apart from the city is turned on its head as a pathetic man living alone with his cat. Elliot Gould plays private investigator Philip Marlowe, who uses his smart-aleck detachment carried along by a natural wave of 1970’s California that Altman exercises for both humour and social commentary. Rich drunks, drugged out youth, multicultural gangsters in touch with their heritage and their feelings, people more than willing to use their friends, all indicate a self-obsessed society, a force as relevant in the 1970’s as the ever-present title song. Originally, Hollywood backed Altman, the eccentric director of M.A.S.H and Nashville, in the hopes that a gritty detective film would cash-in on the... ...grab glimpses of the character's true nature. In The Long Goodbye, these foreground strokes, intended to lay a foundation for audience sympathy with the lead character, are made as prominent as the climax, as well as the end. This is because Marlowe wanders through the action of the film meeting and reacquainting himself with unrelated characters, such as the gatekeeper-impressionist in Terry Lennox’s neighbourhood, and the grocery store clerk, who Marlowe meets again in prison. The time between The Big Sleep and The Long Goodbye signifies a significant evolution of American, or at least Hollywood, culture, from the country's post-WWII optimism to the alarm of Vietnam. The character of Marlowe, it appears, has one foot in each book-end of history. Bibliography Kagan, Norman. American skeptic: Robert Altman's genre-commentary films. Ann Arbor, Mich., Pieran P. 1982. Karp, Alan. The Films of Robert Altman. Metuchen, N.J., Scarecrow P. 1981. McGilligan, Patrick. Robert Altman: jumping off the cliff; a biography of the great American director. New York, St. Martin's P. 1989. Wexman,Virginia Wright. Robert Altman; a guide to references and resources. Boston, Mass, Hall. P. 1984.

Legalizing the Use of Drugs

Many feel today we are losing the war on drugs. When a battle goes to the point where there is no winner, there needs to be a re-evaluation of how to solve the problem. In the case of the war against drugs, years of fighting have caused increased crime, overcrowding of prisons, and the wasted use of money and resources with no results. It is now time to look at alternative methods to solve the nation's drug problem. Although, legalization will increase use of the drug a majority of use will be by those who already use drugs not by new comers who might only try it once out of curiosity. Proof of this can be found in Holland when in 1970 the government legalized the use of marijuana for adults. The legalization of illicit drugs has proved that just because a drug is made legal it does not mean it will cause a rapid rise and abuse by society (Friedman). However, many supporters of continuing the prohibition of drugs believe that by legalizing drugs they will become more accessible and use will therefore increase. They base this argument on past experiments dealing with alcohol prohibition. After the end of prohibition with the 21st amendment, alcohol consumption doubled, while prohibition decreased use by 50 percent (Light). Another example can be found in Liverpool, England. After a recent legalization of drugs in a regulatory program that focuses on the medical benefits of drugs, most drug pushers there left town because there was no longer a market for them. This shows that legalization actually decreases use because of the increased emphasis on rehabilitation and the decrease of drug pushers. Such a dramatic decrease in drug dealers has not only resulted in crime reduction in England but there has also been a decrease of drug use. It is true, legalization will not eliminate the major cause of violent crime; however, most arguments, that say that drug legalization will not decrease crime, deal with the idea that most violent crimes occur as a result of alcohol use. If this is true, legalization will not effect crime that is alcohol related but it will decrease violent crime that is linked to drug dealing and use. The drugs themselves may not cause violent crime, but people involved in the distributing of illicit drugs commit the deadliest crime. By legalizing drugs the dealer would be eliminated and therefore crime would be reduced. Granted, the overall cost of drug use would not decrease; however, supporters of the continued war on drug and the further prohibition of these drugs say that legalization would cost more both socially and economically. They say that legalization would result in increased use and eventually will mean an increase in deaths with. Another result they say will be the decay of family values as a result of increased drug using mothers and children. Actually, the legalization of drugs will put money, which is used for law enforcement into the construction of better rehabilitation and education programs. Education is an essential element in this proposal because through education the problem will find a better than merely covering it up behind jail bars. Economically, for every dollar spent on drug treatment there is a $7 return due to decreased criminal activity. Through the regulation and supervision of the distribution of marijuana, there would be no increases in the number of drug-addicted newborns, nor will it induce the deterioration of society. Thus the overall cost of drug use would decrease and would bring new revenue for our nation. After looking at and knowing the pro and cons of marijuana legalization, I have decided that it is a valid and necessary solution to our country†s drug problem. By implementing such a program the American population can use its money and resources to combat the problem through rehabilitation and education instead of stalling the problem through the legal system. Legalization will decrease violent crime associated with drug dealers; it will decrease the number of users and will lower the wasteful cost, which is connected with the current system. Such legalization will not destroy our youth in any way, because the drugs will only be accessible to adults in the country. If we continue with our current system we will never solve the problem. Drug dealers and addicts will continue to crowd our prisons and plague our streets with violent crime with no hope for help and a better future.

Free Essays on Coyote Holds A Full House In His Hand

Wily Coyote â€Å"Coyote Holds a Full House in His Hand† is a story full of rich cultural symbolism associated with the Pueblo people of the southwestern United States. While carefully acknowledging this fact, the writer of this essay also confesses that much of the significance of these symbols are over her euro-american head, and respectfully chooses to approach the story from the aspect of elements that resonate with her. The story is an interesting presentation full of double entendre with the protagonist narrating the story in the third person giving the reader somewhat of a bizarre look at the â€Å"facts† through his eyes. Our protagonist, although fancying himself a bit of a â€Å"wily coyote,† is more closely what we would call today a loser. He lives, without gainful employment, with his enabling mother. She provides a roof and pays his bills while he justifies his lack of contribution. â€Å"Coyote† is a lonely soul who does not fare well with women. I find it a stretch to feel sorry for him since he walked away from a young woman who loved him and wanted to marry him because he understood she would expect him to provide for her. This clever slouch is not held in much esteem in his town, until one day he has an adventure that he believes will give him a fresh start in the men of his town’s eyes. Coyote is disappointed that a fleshy Mexican lady postmistress has spurned him. As a result of her rejection, Coyote has begun courting through correspondence Mrs. Sekakaku, a lady from another village. Coyote is self-centered enough to believe the postmistress is jealous, even though he has decided she doesn’t like him because he drinks and though the Mexican lady makes it clear she disapproves of the perfumed, pastel letters sent to him by Mrs. Sekakaku. Coyote is hopeful that, with Mrs. Sekakaku in another village, he will have a fresh start, away from where â€Å"nobody understood just what kind of man he was. They th... Free Essays on Coyote Holds A Full House In His Hand Free Essays on Coyote Holds A Full House In His Hand Wily Coyote â€Å"Coyote Holds a Full House in His Hand† is a story full of rich cultural symbolism associated with the Pueblo people of the southwestern United States. While carefully acknowledging this fact, the writer of this essay also confesses that much of the significance of these symbols are over her euro-american head, and respectfully chooses to approach the story from the aspect of elements that resonate with her. The story is an interesting presentation full of double entendre with the protagonist narrating the story in the third person giving the reader somewhat of a bizarre look at the â€Å"facts† through his eyes. Our protagonist, although fancying himself a bit of a â€Å"wily coyote,† is more closely what we would call today a loser. He lives, without gainful employment, with his enabling mother. She provides a roof and pays his bills while he justifies his lack of contribution. â€Å"Coyote† is a lonely soul who does not fare well with women. I find it a stretch to feel sorry for him since he walked away from a young woman who loved him and wanted to marry him because he understood she would expect him to provide for her. This clever slouch is not held in much esteem in his town, until one day he has an adventure that he believes will give him a fresh start in the men of his town’s eyes. Coyote is disappointed that a fleshy Mexican lady postmistress has spurned him. As a result of her rejection, Coyote has begun courting through correspondence Mrs. Sekakaku, a lady from another village. Coyote is self-centered enough to believe the postmistress is jealous, even though he has decided she doesn’t like him because he drinks and though the Mexican lady makes it clear she disapproves of the perfumed, pastel letters sent to him by Mrs. Sekakaku. Coyote is hopeful that, with Mrs. Sekakaku in another village, he will have a fresh start, away from where â€Å"nobody understood just what kind of man he was. They th... Free Essays on Coyote Holds A Full House In His Hand Wily Coyote â€Å"Coyote Holds a Full House in His Hand† is a story full of rich cultural symbolism associated with the Pueblo people of the southwestern United States. While carefully acknowledging this fact, the writer of this essay also confesses that much of the significance of these symbols are over her euro-american head, and respectfully chooses to approach the story from the aspect of elements that resonate with her. The story is an interesting presentation full of double entendre with the protagonist narrating the story in the third person giving the reader somewhat of a bizarre look at the â€Å"facts† through his eyes. Our protagonist, although fancying himself a bit of a â€Å"wily coyote,† is more closely what we would call today a loser. He lives, without gainful employment, with his enabling mother. She provides a roof and pays his bills while he justifies his lack of contribution. â€Å"Coyote† is a lonely soul who does not fare well with women. I find it a stretch to feel sorry for him since he walked away from a young woman who loved him and wanted to marry him because he understood she would expect him to provide for her. This clever slouch is not held in much esteem in his town, until one day he has an adventure that he believes will give him a fresh start in the men of his town’s eyes. Coyote is disappointed that a fleshy Mexican lady postmistress has spurned him. As a result of her rejection, Coyote has begun courting through correspondence Mrs. Sekakaku, a lady from another village. Coyote is self-centered enough to believe the postmistress is jealous, even though he has decided she doesn’t like him because he drinks and though the Mexican lady makes it clear she disapproves of the perfumed, pastel letters sent to him by Mrs. Sekakaku. Coyote is hopeful that, with Mrs. Sekakaku in another village, he will have a fresh start, away from where â€Å"nobody understood just what kind of man he was. They th...

Friendship College Essay

Friendship College Essay Free Online Research Papers What is a home? A home to me is a place where you are comfortable and safe. My safe place is with my friends, away from my house. No one can harm me when I am with them, because they are the ones who care about me most and are by my side no matter what. When I am at other people’s homes, I feel more comfortable, than I do at my own. My mom and my dad split up when I was 18 months old, and I lived with my mom but still got to see my dad every other weekend. Before I was three, I moved from New Milford to Danbury six times. My mom had moved in with her boyfriend, so she left me at my grandmother’s house for almost three months before she finally came back to get me. Even though I was so young at the time, I still feel like she did not want me around, and that pain still gets to me now. I have problems trusting my mom now because she lets all the guys, who are in her life, control what my younger brother and I do; she is our mother and those guys are only her boyfriends. She is the one who is supposed to tell us what to do and care more about us more than them. When I am with my friends, I feel like they care so much about what happens to me and what I do. They always help me with my problems when I need them the most. I trust them because they keep my secrets and are not so quick to judge me because of my mistakes. We can have our fun times and make the worst moments the best moments. I feel like I can be myself when I am with them and they can be themselves around me. When I’m at my friends house, their parents treat me nicely and I just get this feeling that makes me feel safer there. I never thought I could really find a person who really got me and truly understood me, until the beginning of my junior year when I met my friend Marshanti. She is one of my craziest friends, but also one of my most caring friends. When I’m with her, there is nothing stopping us, it’s us against the world. This one time Marshanti and I had gone to Big Y to get some â€Å"munchies† for the night, and the whole time we spent it laughing like crazy and bumping into shelves causing mischief. When my boyfriend and I had broken up, she was the one who talked to me and wanted to know everything that happened and see if I was alright. She never took sides and she never said that either of us were wrong, which was exactly what I needed to hear. It hurts me sometimes when I think that I am a better person now because of my friends and not my parents. I learned a lot from my friends and that’s why I consider them a family to me. One day I will have a better life and it will never be how mine is now. I have grown stronger since I became friends with these people that I care so much about. Some days I wish I did not have the past I had and that the people in it did not exist. Then I think to myself, would I still be the person I am today if it were not for that past and for those people? Would I still be friends with these people if I did not have that past? My home is where my friends are and it will always be that way, that is the best thing I could ever ask for. Research Papers on Friendship College EssayTrailblazing by Eric AndersonPersonal Experience with Teen PregnancyHarry Potter and the Deathly Hallows EssayThe Masque of the Red Death Room meaningsCapital PunishmentHip-Hop is ArtComparison: Letter from Birmingham and CritoThe Fifth HorsemanThe Spring and AutumnArguments for Physician-Assisted Suicide (PAS)

Technological Change in Organizations Essays

Technological Change in Organizations Essays Technological Change in Organizations Essay Technological Change in Organizations Essay Name: Tutor: Course: Date: Technological Change in Organizations The term technological change in an organization refers to the process of integrating new and improved technology in organizational processes to increase the efficiency, performance and productivity of the organization (Jin 20). Recently, the organization I work with experienced this type of change. In this current competitive and global economy, technology plays a major role in determining the success of any organization. Organizational managers are starting to realize that technology is effective in the management of resources and they are starting to respond by incorporating it in their organizational structures. For instance, a majority of organizations now have departments like Information technology department, which is managed by a Chief Information Officer. In preparation for the technological change, the organizational management realized that it was their responsibility to facilitate and enable the technological change by first understanding the dynamics of the change from an objective vantage point (Lorenzi 97). The management further prepared for the technological change by educating the staff on the significance and implications of the change at hand. This was supplemented by frequent involvement and empowerment of the staff (Lewis 144). This step was important because the staff was able to understand the connection between the technological change and the objectives of the organization. The preparation process was concluded by the formulation of an implementation plan that was to be used in the implementation stage In the implementation of the technological change, the management applied a five-step change process, which was incorporated with a technological implementation plan (Paton 101). The first step by the management was acknowledging their responsibility to facilitate and motivate the change after understanding it from an objective standpoint. This step was crucial because it eliminated any resistance to change (Haddad 83). The second step involved creating a vision with core values that guide the future of the organization. The third step was managing the political dynamics of change by developing political support. The fourth step was managing the transition from the existing organizational state to the desired technological state. The final step involved sustaining the momentum needed to carry the change through to completion. The implementation of the technological change had a significant impact to the organization. Technological change enabled the organization to reduce its production costs through office automation and electronic documentation of information (Costa-i-Font 6). The technological change also enabled the organization to improve its communication channels by introducing new methods of communication like electronic mailing and web conferencing. Technology also enabled the organization to increase its productivity by introducing efficient and accurate methods of processing information. In addition, the technological changes played a major role in the expansion of the organization’s economic market, which was initially restricted to the local boundaries (Miner 450). In conclusion, the positive impacts that the technological change had in our organization is proof that change is important. Many organizations today realize that it is important to harness new technologies while at the same time change the organizations parameters in order to support more efficient and effective operations. The incorporation of new technology into any organization will always accompany change and it does not matter whether the structure of the organization is simple or complex (Lewis 21). That is why competitively dominant organizations in our global economy today are flexible to change. Costa-i-Font, Joan, Christophe Courbage, and Alistair McGuire. The Economics of New Health Technologies: Incentives, Organization, and Financing. Oxford: Oxford University Press, 2009. Print. Haddad, Carol J. Managing Technological Change: A Strategic Partnership Approach. Thousand Oaks, Calif: Sage Publications, 2002. Print. Jin, Zhouying. Global Technological Change: From Hard Technology to Soft Technology. , 2011. Print. Lewis, Laurie K. Organizational Change: Creating Change Through Strategic Communication. Chichester, West Sussex, U.K: Wiley-Blackwell, 2011. Print. Lorenzi, Nancy M, and Robert T. Riley. Managing Technological Change: Organizational Aspects of Health Informatics. Berlin: Springer verlag, 2003. Print. Miner, John B. Organizational Behavior: Foundations, Theories, and Analyses. New York: Oxford University Press, 2001. Print. Paton, Rob, and James McCalman. Change Management: A Guide to Effective Implementation. London: SAGE, 2007. Print.

Algae Production For Biofuel Article Example | Topics and Well Written Essays - 750 words

Algae Production For Biofuel - Article Example Traditional ethanol and oil rich plants such as sugarcane, corn and rapeseed have been tried successfully in various regions of the world to yield biodiesel for industrial use. However, the economics of biodiesel production has still to provide figures for potentially feasible and sustainable means to this end. Algae, which are simple botanical forms of life possessing the ability to reproduce at a fast rate with minimal of inputs are being looked at as a potential sources of biodiesel, as some of the millions of its species have been discovered to be rich in triglycerides and other fats/oils necessary for biofuel production. The major advantage of using algae for biofuel production is that they grow in ponds and wastewater, which do not encroach upon terrestrial territory already reserved for the cultivation of food crops. Moreover, algae possess the ability to double their biomass in as less as one day under optimized conditions (Odlare et al, 2011). The high growth rate however ha s to be optimized in relation to oil production within the organism as these two properties are contradictory to each other (Csavina et al, 2011). Methodologies and technologies are therefore being developed to cultivate algae in controlled conditions to achieve this objective. Lipids, sugar and hydrogen gas are considered the primary units of energy and a study at the University of Arizona reveals that algae have a distinct advantage over terrestrial cultivable crops such as corn as they possess a 300 fold advantage in producing the basic units for producing biofuel (Littin, 2011). Although the cost of production of fuel from algae still exceeds the value of the final product, intensive research is going on at the university as well as other parts of the world to optimize the process towards a profitable direction (Littin, 2011). Moreover, it has been discovered that secondary wastewater rich in nitrogen and phosphorus can be utilized to grow algae eliminating the need of fertilize rs (Littin, 2011). In turn, the algae besides producing lipids for potential use as biofuel purify the water as well, resulting in a double benefit. Grown in controlled conditions of specific light exposure and deprivation of nitrogen and sulfur at particular stages of their life promote lipid production in the algae, which are the strategies being explored by the scientists involved in this research (Littin, 2011). Biofuel or biodiesel can be produced from any biomass which has high lipid content. The process involves extraction of oil from the biomass by a process called transesterification which yields triglycerides, which possess the properties ideal for a biofuel (Taylor, 2011). Algae can either be grown in open ponds or in controlled conditions in what is known as a photo-bioreactor (Taylor, 2011). The latter is a sealed aquaculture system in which conditions can be optimized and manipulated according to required objectives of high lipid production by the organisms. Such biore actors are however costly to build as well as maintain and may not be the ideal means for biofuel production from algae. Identification of the appropriate species and varieties of algae growing in natural ponds and wastewater reservoirs in natural conditions, which provide the maximum yield of lipids can be the only means, once identified, to make economically feasible and sustainable methods for

Psychology Journal Article Summary Essay Example | Topics and Well Written Essays - 500 words

Psychology Journal Article Summary - Essay Example While at first he believed that the relationship merely helped the client, in his later works he showed that it not only benefits the client in being able to share, but it also helps the therapist understand the patient, and more accurately assess their personality and needs. Currently, the view of therapeutic alliance is that as the relationship between the client and the therapist develops, the patient is able to transfer their feelings and thoughts and frustrations to the therapist, which allows the patient to let go of what they are carrying. This is a far more successful therapy than merely sharing feelings with a complete stranger. While alliance has been shown to be helpful during therapy, future work and study is still necessary to determine exactly how helpful the therapeutic alliance is, and when it is best used, and when it is best foregone. Future studies will allow therapists to review and study the affect of the therapeutic relationship on the patient-therapist interaction, and the overall success of therapy.

Human security Essay Example | Topics and Well Written Essays - 2000 words

Human security - Essay Example The author believes that the deeper understanding on the ideas will be attained by examining the opposing and concordant views on human security. The articles reviewed have become as compelling as they present realistic and eye-opener accounts, yet antithetical in some degree. Overview of Chandler’s Work The article by David Chandler entitled, Human Security: The Dog That Didn’t Bark provides an important revelation on the â€Å"deconstruction of myth that human security shows a typical conflict between the state and the individual security† (Owen 2008). Chandler’s article is based on the analysis of the two books namely, Human Security: Concepts and Implications written by Shahrbanou Tadjbakhsh & Anuradha M. Chenoy and A Decade of Human Security: Global Governance and New Multilateralisms written by Mclean, Black & Shaw. Chandler started his argument through citing the idea that global policy making overbearingly suggests two different views. One view poi nted out the construal of the dynamics of the society’s power relationships and inequalities, as well as insecurities. The other view pertained to the idea of identifying the interrelatedness, interconnection, and susceptibilities of security threats and the urgency for composite, cooperative, human-centered answers. Chandler’s First Argument While Tadjbakhsh and Chenoy claimed that human, as well as the state, should work interdependently, Chandler (2008) conceded that human and the state are indivisible, yet gave consideration to the importance of examining the problem that transpires regarding the state’s collaboration of its idea outside of its absolute model. Chandler ended up criticizing that the authors are more involved with advocacies instead of the evaluation of definite process of human security. Chandler’s first argument stated that â€Å"human security exaggerates new post-cold war security threats† (Chandler 2008, 435). This argument is compelling as it contradicts to the paradigm of human security. The author contended that one of the prevailing reasons why the human security has been applied wrongly by the state is because it overstated the post-cold war security threats. Chandler (2008) claimed that with the absence of conventional adversaries like terrorists, human security processes close the gap securitization issue like environmental, health, and economic security. Nevertheless, inquiry is not about how these issues are securitized but rather it is more important to evaluate the result of these actions. Since Chandler declined to elaborate the result of these actions, it is safe to assume that he falls short of accusing Tadjbakhsh and Chenoy for not considering the connection between normative theory and policy procedures. Chandler’s Second Argument Further, Chandler (2008, 435) argued that â€Å"human security advocates locate these threats in the developing world.† While there are other pa rt of the developed countries, which also have security problems, advocates can also be considered as correct since majority of the people who experienced security problems like extreme poverty are located in developing countries. These people are more vulnerable that is why it has given more attention. In contrast, Chandler (2008) argued that the causal link of human security processes in a globalized world do not exist at all is somewhat questionable since the actual connection solely depends on what dependent variable is utilized. As what Paris (2001) suggests,

Using Humor to Survive Tragedy Essay Example | Topics and Well Written Essays - 500 words

Using Humor to Survive Tragedy - Essay Example Not a single character in the play profits from propriety. The not so serious characters are the ones who  benefit  in the end; and it is because of their  frivolous  behavior all through the play. This indicates that there is little, if any,  benefit  to being modest. In bill Cosby’s words, when one finds laughter, they can survive some of the worst moments in life.  By using humor, one can  stand  up to the challenges that life brings, no matter tragic they may be.  Situations in life are always changing; once one finds an  intriguing  way to survive a  dark  session, they will make it to the happy parts. In The Importance of Being Earnest, Oscar puts the conventions in the Victorian times aside and presents us the absurdity of such an  ardent  attachment  to seriousness. The  play  presents two young men, Algernon and Jack. Algernon is the symbol of un-earnestness, and Jack is his  ward  in jocularity and deceit. Marriage is of utmost significance in The Importance of Being Earnest. This is because it is what drives the  plot  and is the  primary  subject  for  philosophical  debate and speculation. We  are introduced  to the nature of marriage for the first time when Algernon is talking to his butler, Lane. The subject of marriage stays on for the most part of the  play  as it develops. Jack and Algernon talk about the important things in marriage, and what matters in it. They  talk  of it as either a matter of â€Å"pleasure† or â€Å"business†. During Victorian times, there were conventions on marriage; with  regard  to its  purpose  and  nature. These include such things as the social position of a person, the  income  the person had as well as the person’s  character. Algernon and jack are remarkably in the know of these assumptions, as well. Society expects them to follow these conventions, but they do not. They ridicule th ese customs, and, in situations where they cannot, they assume the

The Negative Effect Of Middle Name Atsitso Essay

The Negative Effect Of Middle Name Atsitso - Essay Example These myths have made it worse for me especially in an effort to accept that name as my own. This name has really had negative implications in my life. As seen in the research conducted by Crook, it is in the shrines that bodies are laid and at times the reasons behind the deaths are very unclear (67). The author gives a good example of the ones at Bardney that were laid in a shrine (Crook 67). This explains the mysteries that lie in the shrines as the author claims that the ones at Bardney were indeed unclear. Relating this to my name meaning a shrine, I do not like this aspect at all. Persons may relate to the cultic features of the shrine to my name as well as my personality which does not sound good to me at all. In the work as well, Crook is of the thought that shrines are constructed using the remains of materials that were used to put up other buildings (104). A good example is that of Eadwig’s time when shrines were rebuilt using the old front and back plates (Crook 104). In the event that I relate this fact to my life, I strongly feel that I do not want anyone to call me by that name Atsitso ever again. In my opinion, I relate the construction of the shrines as an afterthought of other constructions. I do not believe I am a product of an afterthought. This hurts my self-esteem a great deal; that is why I forbid people to ever call me using that name. In shrines, dead bodies are laid to rest. Even after burials, some bodies are normally raised from the ground and laid to rest in the shrines. Crook gives an example of Aldhelm who was exhumed and laid to rest in a shrine (104). Who would want a name that relates to shrines and a place for dead bodies? This explains why I renounce my name that has a lot to do with ones and dead bodies. At times people ridicule me because of the same. At times people ridicule me because of the same. As the days pass, my personality is greatly affected and will continually ask people to never call me by that name.

Using Humor to Survive Tragedy Essay Example | Topics and Well Written Essays - 500 words

Using Humor to Survive Tragedy - Essay Example Not a single character in the play profits from propriety. The not so serious characters are the ones who  benefit  in the end; and it is because of their  frivolous  behavior all through the play. This indicates that there is little, if any,  benefit  to being modest. In bill Cosby’s words, when one finds laughter, they can survive some of the worst moments in life.  By using humor, one can  stand  up to the challenges that life brings, no matter tragic they may be.  Situations in life are always changing; once one finds an  intriguing  way to survive a  dark  session, they will make it to the happy parts. In The Importance of Being Earnest, Oscar puts the conventions in the Victorian times aside and presents us the absurdity of such an  ardent  attachment  to seriousness. The  play  presents two young men, Algernon and Jack. Algernon is the symbol of un-earnestness, and Jack is his  ward  in jocularity and deceit. Marriage is of utmost significance in The Importance of Being Earnest. This is because it is what drives the  plot  and is the  primary  subject  for  philosophical  debate and speculation. We  are introduced  to the nature of marriage for the first time when Algernon is talking to his butler, Lane. The subject of marriage stays on for the most part of the  play  as it develops. Jack and Algernon talk about the important things in marriage, and what matters in it. They  talk  of it as either a matter of â€Å"pleasure† or â€Å"business†. During Victorian times, there were conventions on marriage; with  regard  to its  purpose  and  nature. These include such things as the social position of a person, the  income  the person had as well as the person’s  character. Algernon and jack are remarkably in the know of these assumptions, as well. Society expects them to follow these conventions, but they do not. They ridicule th ese customs, and, in situations where they cannot, they assume the

Age of enlightment Essay Example | Topics and Well Written Essays - 750 words

Age of enlightment - Essay Example The second treatise of local government The author in this article conveys that man by nature is free and has no obligation to subject to anybody’s will. He neglects the idea of government and the punishment imposed by religious concepts.The author suggests that human being belonging to same species should not be subjected to discrimination and slavery but to equal freedom. Adam smith – Wealth of nations The author in this book explains about the feudalism and beurecracy existed during the industrial revolution of Europe. He beloved that feudalism spreading in Europe could hinder the industrial growth and only thing could save it is socialism. He believes that development is due to the specialization of labor and this only can give material well being. He mentions that self love is the reason for prosperity in man which is a nature only found in human beings. He claims that market is a place where individual co -operates with each other and where the talents of individu als are shared for material benefit. His theory says that the value of a thing sold in a market is the proportion of labor put in the making o f it and brought into the market. Comparison of Locke and Adam theory The similarity in both Locke and Adam’s proposition is that both believe in the human rights of people. They believed in the labor of the human beings and the value attached to it and right attached to it. Both these authors were in support of the laborers and working men. Both the authors talk about the discrimination of government towards the poor and needy. They both talk about property of nature and the law of nature. Locke suggests that â€Å"Adam and Eve, and after them all parents were, by the law of nature, under an obligation to preserve, nourish and educate the children, they had begotten†. In a way, both favor socialism and equal distribution of power, property and right to people. They demand that it in natural state, people have the right to do wh at they wanted to and in any case should not be subjected to slavery. Natural liberty was central theme to both of their writing. Locke claims that the government is formed in order to protect the property and Adam smith also talks about labor and property that is wealth of nation. Both the authors believe in a market which works freely and without any discrimination. Smith believed that society functioned in a capitalist way and mostly wants to exploit the laborers and working class. Smith mentions that â€Å"There is no art which one government sooner learns of another than that of draining money from the pockets of the people†. Smith claims that property is the effort of working class and same is said by Locks that property is labor mixed with an object. Both of them emphasize less on a government who disregard human rights and interests of common men. Contrast between Locke and Smith theory Locke mainly discuss about a community where individuals have free interest and ac quired natural freedom. He mainly focuses on human rights and property .On the other hand Adam Smith focuses on labor and its value and on the division of labor. According to Smith â€Å"In general, if any branch of trade, or any division of labor, be advantageous to the public, the freer and more general the competition, it will always be the more so†. Locke mainly mentions about the Government and their abusive way of governing the people. According to Locke â€Å"The legislature acts against the trust reposed in them, when they endeavor to invade the property of the subject, and to make themselves, or any part of the community, masters, or arbitrary disposers of the lives, liberties or fortunes of the people† He claims that instead of representing the people, government represent

Deborah Moggach uses humour to address social issues consider how she does this, paying particular attention to her use of language Essay Example for Free

Deborah Moggach uses humour to address social issues consider how she does this, paying particular attention to her use of language Essay n this essay I will look at how Deborah Moggach uses humour to address social issues. I will give my own opinion and I will also pay particular attention to her use of language. In this essay I will focus on ‘fool for love’ by Deborah Moggach, she addresses the social issues of older women having a relationship with younger men. In this story there is a middle age mother with two teenagers and she found a 26 year old man for a relationship through her day time job in a dispatch room. Deborah Moggach uses humour to address a social issue a number of times throughout the story. The first time we see this is when Deborah Moggach the 26 year old man ask Esther out, ‘want to help me buy a Christmas present for my mum’. This is used as a social issue as he is asking to spend time with her. However the humour comes in later when Deborah Moggach says ‘but did he just want the advice of mature woman’. This makes the audience think and brings reality into the story and reminds us of Esther’s age. We are reminded by the young man’s age later on in the story through humour when Esther is telling him about the state of her son’s bedroom until she realise he is young himself ‘you couldn’t complain about adolescents to somebody who was practically one himself’. This humour is shown as it is as if Esther is relating the young man of her dreams to her son. Deborah Moggach then uses humour when she gets into how Esther feels about how long it had been since she had fallen in ‘love again’ and ‘Since she had shaved her legs every single day’. This humour is shown to emphasis what it is like to fall in love and what ladies do on a daily bases to show that they care top their man. This is also linked to a social issue as it is the reason she is ‘shaving her legs on a daily bases’ for the social aspect of seeing the man. In the sixth paragraph of ‘fool for love’, Deborah Moggach uses humour by saying ‘she had lent him  £10-he never had any money-and he still paid her back’. This is used in a social issue as they are socialising together more carefully now as the story goes on. This is also humours’ as people can relate towards it and it shows that he cares for his feelings and cares for her. ‘Fool for love’ by Deborah Moggach is a story that people are able to relate to well. It seems to be that everyone has fallen in love and had ups and downs, whether they would die to be with them for the rest of their lives or be with them for a period of time. ‘Fool for love’ emphasises just how strong love can be and how powerful it is to some people and this is how people are able to relate towards the story. Humour for a social issues is used a lot of the time throughout the story as a mature woman with a younger man does happen it is not too common which gives Deborah Moggach the perfect chance to play with the writing and ass humour into the story. ‘Fool for love’ is all about social issues with Esther meeting a new young man at work to meeting her son from the airport. I lot of the things that Esther does is because of a social issue and how she wants to come across to people when being social able.

Evolution of Australian Flora: Hymenopteran Visual Systems

Evolution of Australian Flora: Hymenopteran Visual Systems Abstract Very little work has been done on the evolution of floral colour diversity, outside of Europe and the Middle East. In particular, we know almost nothing about the evolution of the Australian flora in the context of hymenopteran visual systems. Such a study is likely to be important due to the geologically long isolation of the Australian flora and the high proportion of endemic plant species. The aims of this study were to investigate the colour of Australian native flowers in the context of hymenopteran visual systems, the innate colour preferences of Australian native bees (Trigona carbonaria), and the interactions between native bees and a food deceptive orchid (Caladenia carnea). Firstly, I found that the discrimination thresholds of hymenopterans match up with floral colour diversity and that hymenopterans appear to have been a major contributor to flower colour evolution in Australia. Secondly, I found that Trigona carbonaria has innate preferences for wavelengths of 422, 437 a nd 530 nm. Thirdly, I found that bees were able to habituate to orchid flowers based on colour, thus potentially explaining the colour polymorphism of Caladenia carnea. Together, my study suggests that the evolution of the Australian flora has been influenced by hymenopterans. 1. Introduction Plant-pollinator interactions The mutual interactions between pollinators and plants have been suspected in driving angiosperm radiation and diversification in the past (Regal 1977; Crepet 1984; McPeek 1996). The obvious mutual benefit is that pollinators depend on the pollen and/or nectar of flowering plants for food and, in return, partake in the incidental transfer of pollen necessary for plant reproduction (Faegri and van der Pijl 1978; Harder, Williams et al. 2001). Worldwide, it is estimated that more than 67% of angiosperm plants rely on pollination by insects (Tepedino 1979). Hence, pollinators play a critical role in the persistence and survival of flowering plants, which are of high value to the human food chain (Kearns and Inouye 1997; Klein, Vaissiere et al. 2007). Flower colour signals and sensory exploitation Colour is the result of the visible light being absorbed or reflected off objects and then processed by the eye and brain of an animal (Le Grand 1968). Light is part of the electromagnetic spectrum, and can be quantified by the wavelength of different photons of energy (Bueche 1986). The wavelengths reflected off the object are perceived by a visual system as the object’s colour. For example, light that appears blue to a human observer can be described by a dominant wavelength of 400nm, whilst light that appears red is 700nm. Ultraviolet light falls between 300-400nm and can be seen by bees, but not humans. Flower colours have been influenced by the sensory receptors of insects, including their colour vision, which is different to human vision. Humans have a red, blue and green receptor (Chittka and Wells 2004). In contrast insects have a UV, green and blue receptor (Chittka and Wells 2004). As human vision is very different to a hymenopterans’ colour visual system, one cannot discuss a bees’ colour perception according to human colour terms such as red or blue. Therefore, this thesis will discuss colours according to wavelength. Colour is one of the most important floral signals plants use to communicate information to insect pollinators (Giurfa, Vorobyev et al. 1996; Dyer, Spaethe et al. 2008). Although it is known that pollinators select flowers based on morphology, nectar availability, size, and odour (Giurfa, Nà ºÃƒ ±ez et al. 1994; Kunze and Gumbert 2001; Spaethe, Tautz et al. 2001; Whitney and Glover 2007), colour is known to play a critical role in enabling pollinators to detect and discriminate target flowers from a biologically important distance of up to 50 cm (Giurfa, Vorobyev et al. 1996; Dyer, Spaethe et al. 2008). Our understanding of the evolution of colour vision in insects has advanced considerably in recent years. In the past, studies of colour perception were limited due to little information on the colour visual system of insects (Frisch 1914; Daumer 1956). It is now possible to evaluate how flower visual signals appear to the visual system of hymenopteran pollinators, using spectrophotometer and colorimetry techniques, which allows quantitative evaluations of how complex colour information is perceived by insect pollinators (Chittka 1992) (fig. 1). Previous research has revealed that colour discrimination in hymenopterans is phylogenetically ancient, with different hymenopterans sharing similar colour perception (Helversen 1972; Chittka and Menzel 1992). Importantly, colour discrimination in the hymenoptera is known to predate the evolution of floral colour diversity (Chittka 1996). Here, recent research has revealed remarkable convergence in the evolution and distribution of floral colours in different parts of the world. Specifically, in a seminal paper, Chittka (1996) showed that flowering plants in both Europe and the Middle East have adapted their colour signals to the visual systems of bees, with flower colours in these regions closely matched to the visual receptors of hymenopterans (Chittka 1996). However, outside of Europe and the Middle East, very little work has been done on the evolution of floral colour diversity. In particular, we know almost nothing about the evolution of the Australian flora in the context of hy menopteran visual systems. This is an important question to investigate due to the long isolation of the Australian flora and the high proportion of endemic plant species. I hypothesise that the Australian floral coloration will closely match the discrimination thresholds of hymenopterans as recent evidence suggests that insect pollinators supported the early spread of flowering plants (Hu, Dilcher et al. 2008). Innate colour preferences of bees Charles Darwin was the first to state that innate preferences could allow an inexperienced pollinator to find a food source (Darwin 1877). Pollinators may use certain traits of flowers such as morphology, scent, temperature and colour to locate food (Heinrich 1979; Menzel 1985; Dyer, Whitney et al. 2006; Raine, Ings et al. 2006). Previous studies evaluating innate colour preferences have tended to focus on two species: the European honey bee (Apis mellifera) and bumblebee (Bombus terrestris). By contrast, no studies have looked at the innate colour preferences of Australian bees and how this affects their choices for flowers. We know that European bumblebees and honeybees show strong preferences for violet and blue (400-420nm) throughout their geographic range (Chittka, Ings et al. 2004) ,which interestingly correlates with the most profitable food sources (Lunau and Maier 1995; Chittka and Raine 2006). These preferences are likely to have had an impact on the relative success of dif ferent flower colours in regions where these bees are dominant pollinators (Chittka and Wells 2004). Consequently, information on the innate preferences of Australian bees will be important to understand hymenopteran plant interactions in the Australian context. Pollinator learning and food deceptive orchids Most plants reward their pollinators with nectar or pollen. However, some species do not offer floral rewards and, instead, employ a range of deceptive techniques to trick insects into performing the task of pollination. Deceptive pollination strategies are particularly well known and widespread among orchids (Jersà ¡kovà ¡, Johnson et al. 2006). For instance, approximately 400 orchid species are known to achieve pollination through sexual deceit, luring unsuspecting male insects to the flower through olfactory, visual and tactile mimicry of potential mates. More common are food deceptive orchids which are believed to number as many as 6,000 species (one-third of orchids) (Jersà ¡kovà ¡, Johnson et al. 2009). Food mimicking orchids employ bright colours to falsely advertise the presence of a reward to attract naive pollinators (Ackerman 1986; Nilsson 1992; Jersà ¡kovà ¡, Johnson et al. 2006). The common occurrence of food deception in orchids suggests that this form of pollinat ion by deception is an extremely successful evolutionary strategy (Cozzolino and Widmer 2005). Visits by pollinators to deceptive plants are influenced by pollinator learning. In the case of sexual deception, previous research shows that insects quickly learn unrewarding flower decoys and avoid them. For example, male insects learn to avoid areas containing sexually deceptive orchids (Peakall 1990; Wong and Schiestl 2002). However, whether insects can learn to avoid food deceptive orchids remains to be investigated. In addition, high levels of variability in floral traits, particularly flower colour and floral scent, may interrupt the associative learning of insects by preventing their ability to become familiar with deceptive flowers (Schiestl 2005). Indeed, variation in colour, shape and fragrance is evident in non-model food-deceptive orchids (Moya and Ackerman 1993; Aragà ³n and Ackerman 2004; Salzmann, Nardella et al. 2007). However, previous studies have only looked at pollinator preference for colour morphs (Koivisto, Vallius et al. 2002), rather than assessing if vari able flower colour slows down the ability of naive pollinators to learn unrewarding flower decoys. Furthermore, there is a need to incorporate a combination of colour vision science and behavioural ecology to understand how a bee perceives the orchid flowers, as bees have a different visual system to humans. Although humans cannot see ultra-violet light, UV sensitivity is common in some animals (Tovà ©e 1995). UV sensitivity has been found in insects, birds, fish and reptiles (Marshall, Jones et al. 1996; Neumeyer and Kitschmann 1998; Cuthill, Partridge et al. 2000; Briscoe and Chittka 2001). Studies on UV vision in an ecological context have mainly focused on species specific signalling and mate choice (Bennett, Cuthill et al. 1996; Bennett, Cuthill et al. 1997; Pearn 2001; Cummings, Garc et al. 2006). However, few studies have looked at the role of UV signals in attracting bees to orchids. Previous studies have shown that the presence of UV reflecting crab spiders attracts honeybees to daisies (Heiling, Herberstein et al. 2003). In a similar study, Australian native bees (Austroplebia australis) were attracted but did not land on flowers with UV reflecting crab spiders (Heiling and Herberstein 2004). However, the role of UV signals in orchids is not well studied. In particular, it is not known if the UV signal is important in attracting naive bees to food deceptive orchids. Thus, it will be useful to know if UV signals might also serve to lure naive pollinators to deceptive flowers to understand deceptive pollination. Aims This project will investigate Australian flower colour diversity in the context of hymenopteran visual systems, the innate colour preferences of Australian native bees (Trigona carbonaria) and their interactions with a food deceptive orchid (Caladenia carnea). This study aims to address the following questions: 1. Is there a link between hymenopteran vision and Australian floral coloration? 2. Does an Australian native bee (Trigona carbonaria) have innate colour preferences? 3. Does a food deceptive orchid (Caladenia carnea) exploit the innate colour preferences of Trigona carbonar 2. Methods Part 1. Is there a link between hymenopteran vision and Australian floral coloration? Flower collection and spectral reflectance functions of Australian native plant flowers Australian native flowers were collected from Maranoa Gardens, Balwyn (melway ref 46 F7). Maranoa Gardens was chosen due to the diverse collection of species from all over Australia. Flowers were collected once a month, from May to January. A colour photograph was taken of the flower for identification. I also took a UV photograph for all flowers, using a digital UV camera [Fuji Finepix Pro S3 UVIR modified CCD for UV imaging] with calibrated UV-vis grey scales (Dyer, Muir et al. 2004). As UV rays are invisible to the human eye (Menzel and Blakers 1976; Dyer 2001), this photo enabled any UV reflectance areas of the flower to be measured by the spectrophotometer (Indsto, Weston et al. 2006). The spectral reflection functions of flowers were calculated from 300 to 700 nm using a spectrophotometer(S2000) with a PX-2 pulsed xenon light source attached to a PC running SpectraSuite software (Ocean Optics Inc., Dunedin, FL, USA). The spectrophotometer was used to quantify the colour of the flower as wavelength. The white standard was a freshly pressed pellet of dry BaSO4, used to calibrate the spectrophotometer. A minimum of three flowers from each plant were used for each spectral analysis. I evaluated a sample of 111 spectral measurements from Australian flowering plants, encompassing a representative variety of plant families (fig. 2). Correlations between spectral reflectance functions of different plant flowers and trichomatic vision of the honeybees To understand if there is a link between hymenopteran vision and Australian native flowers, I used the methodology used by Chittka and Menzel (1992). In that study, Chittka and Menzel looked for correlations between flower spectra sharp steps of different plant flowers and trichomatic vision of the honeybees. Sharp steps are a rapid change in the spectra wavelength (Chittka and Menzel 1992) (see fig. 3 for an example of a sharp step). These steps cross over different receptors, thereby producing vivid colours that stand out from the background. Furthermore, a colour signal will be more distinguishable to a pollinator if the sharp steps match up with the overlap of receptors in a visual system. Thus, the main feature of a flower wavelength is a sharp step. For this study, I defined a sharp step as a change of greater than 20 % reflectance in less than 50 nm of the bee visual spectrum. The midpoint of the slope was determined by eyesight as described by Chittka and Menzel (1992), as th e nature of curves varied with each flower. The absolute numbers of sharp steps within each flower spectra were counted. The frequencies are shown in fig. 4b. As hybrid plants are artificially selected by humans, hybrid flowers were not included in the analyses. Generating a Hexagon colour space To evaluate how flower colours are seen by bees, I plotted the flower colour positions in a colour hexagon space. A colour space is a numerical representation of an insect’s colour perception that is suitable for a wide range of hymenopteran species (Chittka 1992). In a colour space, the distances between locations of a two colour objects link with the insect’s capacity to differentiate those colours. To make the colour space, the spectral reflectance of the colour objects were required, as well as the receptor sensitivities of the insect. For Trigona carbonaria, the exact photoreceptors are currently unknown, but hymenopteran trichromatic vision is very similar between species as the colour photoreceptors are phylogenetically ancient (Chittka 1996). Thus, it is possible to model hymenopteran vision with a vitamin A1 visual template (Stavenga, Smits et al. 1993) as described by Dyer (1999). I then predicted how the brain processed these colour signals by using the avera ge reflectance from each flower, and calculating the photoreceptor excitation (E) values, according to the UV, blue and green receptor sensitivities (Briscoe and Chittka 2001) using the methods explained by Chittka (1992). The UV, blue and green E-values of flower spectra were used as coordinates and plotted in a colour space (Chittka 1992). The colour difference as perceived by a bee was calculated by the Euclidean distance between two objects locations in the colour hexagon space (Chittka 1992). Modelling the distributions of Australian flower colours according to bees’ perception I analysed the most frequent flower colour according to a bees’ colour perception using the methods of Chittka, Shmida et al. (1994). I plotted the Australian flower colours in a colour space (Fig 5a). A colour space is a graphical representation of a bees’ colour perception. A radial grid of 10 degree sectors was placed over the distribution of colour loci and the number of floral colour loci within each sector was counted(fig. 5b). Part 2. Does an Australian native bee (Trigona carbonaria) have innate colour preferences? Insect model and housing Trigona carbonaria is an Australian native stingless bee that lives in colonies of 4000-10000 individuals (Heard 1988). In the wild, stingless bees live in hollows inside trees (Dollin, Dollin et al. 1997). Trigona carbonaria has a similar social structure to the honeybee (Wille 1983). They are common to North Eastern Australia and are a potentially important pollinator for several major commercial crops (Heard 1999). A research colony (ca. 4000 adults and 800 foraging individuals) of T. carbonaria was propagated for the experiments by Dr Tim Heard (CSIRO Entomology, 120 Meiers Rd, Indooroopilly 4068, Australia) as described in the paper by Heard (1988). Bees were maintained in laboratory conditions so that no previous contact with flowers had been made. For this study, a colony was placed in a pine nest box (27.5 x 20 x 31 cm; LWH) and connected to the foraging arena by a 16 cm plexiglass tube, containing individual shutters to control bee movements. All laboratory experiments were conducted in a Controlled Temperature Laboratory (CTL) at Monash University, Clayton, School of Biological Sciences (CTL room G12C dimensions 3 x 5m), during the months of July 2009- January 2010. Relative humidity (RH) was set to 30%, and the temperature was set to 27  °C (SPER-Scientific Hygrometer, Arizona, USA), as this set up approximately matches conditions in Queensland for insect pollinators (Heard and Hendrikz 1993). Illumination (10/14 hr day/night) was provided by four Phillips Master TLS HE slimline 28W/865 UV+ daylight fluorescent tubes (Holland) with specially fitted high frequency (>1200Hz) ATEC Jupiter EGF PMD2x14-35 electronic dimmable ballasts which closely matches daylight conditions for trichromatic hymenoptera (Dyer and Chittka 2004). The flight arena (1.2 x 0.6 x 0.5m; LWH) was made of a coated steel frame with laminated white wooden side panels. The arena floor was painted foliage green, and the arena lid was covered with UV transparent plexiglass. Experimen ts were conducted from 1pm-3pm to control for time of day, as this is when bees are most active (Heard and Hendrikz 1993). Pre-training Bees were habituated to the flight arena for seven days. Naive foragers (i.e. bees that had never encountered real or artificial flowers) were initially pre-trained to forage in the flight arena on three rewarding aluminium sanded disks (25 mm in diameter), with a 10-ÃŽ ¼l droplet of 15% (w/w) sucrose solution placed in the centre. The disks were placed on vertical plastic cylinders (diameter = 25 mm, height = 100 mm), to raise them above the floor of the flight arena so that bees learnt to fly to the disks. Pre-training allows bees to become habituated to visiting artificial flowers for further experiments. The aluminium sanded disks were chosen as neutral stimuli because they have an even spectral reflectance curve in the spectral visual range of the bees, fig. 6. The sucrose solution reward on these training disks was refilled using a pipette after it was consumed by foraging bees. The spatial positions of these training disks were pseudo randomised, so that bees would not learn t o associate particular locations with reward. Bees were allowed a minimum of two hours to forage on the pre-training disks before data collection Innate colour preference testing To test the innate colour preferences of naive bees, I performed simultaneous choice experiments with flower-naive bees using artificial flowers that simulated the floral colours of natural flowers. The aluminum rewarding disks were replaced by the ten unrewarding, coloured artificial disks in the original flight arena. Artificial flower stimuli were cut in a circle (70 mm diameter) from standardized colour papers of the HKS-N-series (Hostmann-Steinberg K+E Druckfarben, H. Schmincke Co., Germany). In each experiment the same set of ten test colours (1N pale yellow, 3N saturated yellow, 21N light pink, 32N pink, 33N purple, 50N blue, 68N green, 82N brown, 92N grey, back of 92N white) were used. These colours were chosen as they have been used in innate colour experiments with other hymenopterans (Giurfa, Nà ºÃƒ ±ez et al. 1995; Kelber 1997; Gumbert 2000), and the colours are also widely used in other bee colour experiments (Giurfa, Vorobyev et al. 1996). The coloured paper disks were placed on vertical plastic cylinders (diameter = 15 mm; height = 50 mm), to raise them above the floor of the flight arena. The gate was shut in the arena to ensure the bees used in each trial were separated from the next trial. The number of landings and approaches to the stimuli were recorded for one hour. Approximately 200 bees were used for each trial. The spatial positions of the artificial flowers were pseudo randomised in a counter balance fashion every 15 minutes. After each trial, the colour disks were aired and wiped with a paper tissue to remove possible scent marks, which are known to affect experiments with honeybees (Schmitt and Bertsch 1990; Giurfa and Nà ºÃƒ ±ez 1992). I conducted each subsequent trial after removing the used bees from the system, to ensure that the bees in the next trial were replaced with naive foragers. It is known that perception of colour can be influenced by background colour (Lunau, Wacht et al. 1996). Therefore, I also tested colour choices on other background colours of grey and black. The results are qualitatively similar (fig. 8b), so only data from the biologically relevant green background was used for subsequent analysis. Analysis of colour stimuli As bees see colours differently to humans, I quantified stimuli according to five parameters: wavelength, brightness, purity (saturation), chromatic contrast to the background and green receptor contrast. Dominant wavelength was calculated by tracing a line from the centre of the colour hexagon through the stimulus location to the corresponding spectrum locus wavelength (Wyszecki and Stiles 1982). Brightness was measured as the sum of excitation values of the UV, blue and green receptors (Spaethe, Tautz et al. 2001). Spectral purity of the stimulus was calculated by the percentage distance of the stimulus in relation to the end of the spectrum locus (Chittka and Wells 2004). Chromatic contrast was calculated as the distance of a colour stimulus from the centre of the colour hexagon relative to the background. Chromatic contrast is important as perception can be affected by background colour (Lunau, Wacht et al. 1996). Green receptor contrast was measured as the green receptor excitat ion from a stimulus relative to the background (Giurfa, Nà ºÃƒ ±ez et al. 1995). This contrast is relevant as green receptors and green contrast are known to affect motion in bees (Srinivasan, Lehrer et al. 1987). Statistical analyses The impact of wavelength on number of landings by Trigona carbonaria was investigated using a single factor analysis of variance (ANOVA) and a post hoc Tukeys HSD test (ÃŽ ±=0.05) (Quinn and Keough 2002) using the number of landings as the dependent variable and wavelength of stimuli as the independent variable. Brightness, purity (saturation), chromatic contrast to the background and green receptor contrast of stimuli were analysed using the Spearmans rank correlation test against choices. Statistical analyses were conducted using R statistical and graphical environment (R Development Core Team, 2007). Statistical significance was set to P≠¤0.05. Part 3. Does a food deceptive orchid (Caladenia carnea) exploit the innate colour preferences of Trigona carbonaria? Plant model Caladenia carnea is a widespread species, common to eastern Australia. The orchid is highly variable in colour, ranging from pink to white. It is pollinated by Australian native bees of the Trigona species (Adams and Lawson 1993).With bright colours and fragrance, this orchid achieves pollination by food mimicry (Adams and Lawson 1993). Thus, due to the colour variation of the orchid, C. carnea is an excellent model with which to examine floral exploitation of potential pollinators. Caladenia carnea flowers were supplied by private growers from the Australasian Native Orchid Society. Can Trigona carbonaria perceive a difference between pink and white flowers of Caladenia carnea? Colorimetric analysis of the pink and white Caladenia carnea flowers were used to investigate whether different colours of the orchid would be perceived as similar or different to a bees’ visual system. A spectrophotometer was used to take four measurements of each flower colour (pink versus white). The actual measurements used in the analysis were an average of each colour (Dyer, Whitney et al. 2007). To predict the probability with which insect pollinators would discriminate between different flowers, these spectra were plotted as loci in a hexagon colour space (Chittka 1992) (see ‘hexagon colour space’ methods). Choice experiments I conducted trials testing the preferences of bees when offered a dichotomous choice between a white versus pink Caladenia carnea flower. Each trial took place inside a flight arena. Each white and pink flower used in a trial were matched for size, placed into indiviual plastic containers (diameter= 5 cm, height=5 cm) and placed in the arena with a distance of 10 cm between flower centres. Each container was covered with Glad WrapTM (The Clorox Company, Oaklands, CA, USA) to remove olfactory cues as they are known to in ¬Ã¢â‚¬Å¡uence the choice behaviour of honeybees (e.g. Pelz, Gerber et al. 1997; Laska, Galizia et al. 1999). Approximately 50 bees were let into the arena for each trial. The  ¬Ã‚ rst contact made by a bee with the Glad WrapTM within a distance of 4 cm, was recorded as a choice of that  ¬Ã¢â‚¬Å¡ower (Dyer, Whitney et al. 2007). The number of landings were recorded to the flowers for five minutes. After each trial, the Glad WrapTM was changed to prevent scent ma rks. In addition, individual flowers and spatial positions were randomised. Individual bees were sacrificed after each trial to avoid pseudo replication. Does the UV signal affect the attraction of bees to orchid flowers? To investigate whether the UV re ¬Ã¢â‚¬Å¡ectance of the dorsal sepal affected the response of bees, I offered bees the choice between two white orchids, one with a UV signal and the other without (N=16). The UV signal was removed by applying a thin layer of sunscreen (Hamilton SPF 30+, Adelaide, SA, Australia) over the dorsal sepal. Spectral reflectance measurements were taken to ensure that the sunscreen prevented any reflection of UV light (below 395 nm) from the sepals and did not change the reflectance properties of the orchid. In addition, spectral measurements of orchid sepals under Glad WrapTM confirmed that the foil was permeable to all wavelengths of light above 300 nm and did not obscure the reflectance of flowers. Do bees display preferences when choosing between pink versus white orchid flowers? To assess whether bees show a preference for pink or white variants of the orchid Caladenia carnea, I offered bees a simultaneous choice between a pink or white flower (N=16). See procedures for choice testing. Do bees habituate to non-rewarding orchids based on differences in floral coloration? I conducted a two stage experiment to investigate if bees could learn to habituate to a non-rewarding flower colour over time and whether bees adjusted their subsequent flower choice depending on the flower colour encountered previously. At stage 1 of the experiment, native bees were presented with one flower, either white or pink. Flowers were placed in a container with Glad WrapTM. Landings to the flower were recorded at the start and again at the 30 min mark. At stage 2, the flower from stage 1 was swapped with a new flower colour and the number of landings were scored for 5 minutes. Flowers were randomised and Glad WrapTM changed to prevent scent marks after each trial. Once again, bees were used only once per experiment. Statistical analyses For experiments 2, 3 4, numbers of landings by naive bees to flower pairs were compared using two tailed paired t-tests. A two factor ANOVA was used to analyse whether bees habituate to non-rewarding orchids based on differences in floral coloration. The dependent variable was the number of landings and the two independent variables were previous flower colour and new flower colour. 3. Results Part 1. Is there a link between hymenopteran vision and Australian floral coloration? Correlations between the inflection curves of different plant flowers and trichomatic vision of hymenopterans The analysis of 111 spectral reflection curves of Australian flowers reveals that sharp steps occur at those wavelengths where hymenoterans are most sensitive to spectral differences (fig. 4b). There are three clear peaks in sharp steps (fig. 4b). It is known that hymenopteran trichomats are all sensitive to spectral differences at approximately 400 and 500 nm (Menzel and Backhaus 1991; Peitsch, Fietz et al. 1992). Hence, the peaks at 400 and 500 nm can be discriminated well by hymenopteran trichomats, as illustrated by the inverse Δ ÃŽ »/ÃŽ » function (solid curve shown in fig. 4a) of the honeybee (Helversen 1972), which is an empirically determined threshold function which shows the region of the electromagnetic function that a bees’ visual system discriminates colours best. In summary, the spectral position of receptors of trichomatic hymenopterans are correlates with steps in the floral spectra of Australian flowers. The distributions of Australian flower colours according to bees’ perception The floral colour loci are strongly clustered in the colour hexagon (fig. 5a). Blue-green flowers are the most common in the perception of bees, while pure UV flowers were the rarest (fig. 5b). Part 2. Does an Australian native bee (Trigona carbonaria) have innate colour preferences? Effect of brightness, spectral purity, chromatic contrast and green receptor contrast on colour choices There was no significant effect of stimulus brightness on choice frequency (rs= 0.333, n=10, p= 0.347; fig. 7a). There was no significant effect of spectral purity on choice frequency (rs = 0.224, n=10, p= 0.533; figure 7b). There was no significant correlation effect of chromatic contrast on choice frequency (rs = 0.042, n=10, p= 0.907; figure 7c). There was no significant effect of green receptor contrast on choice frequency (rs = 0. 0.552, n=10, p= 0.098; figure 7d). Effect of wavelength on colour choices Stimuli colours are plotted in figure 8a, as they appear to a human viewer to enable readers to understand the correlation between colour choices. However, all statistical analyses were conducted with stimuli plotted as wavelength due to the different visual perception of bees and humans (Kevan, Chittka et al. 2001). There is a significant effect of wavelength on the number of landings by Trigona carbonaria (Single factor ANOVA, F9,110 = 5.60, P

Death in T.S. Eliots The Wasteland and Maddys No Past, No Present, No Future :: Death Eliot Maddy Wasteland Future Past Essays

Death in T.S. Eliot's The Wasteland and Maddy's No Past, No Present, No Future Death is an inevitable fact that everyone experiences at some point in their lives. Whether it is losing a friend, family member, someone famous and well known, or finally themselves, everyone knows what it's like to deal with the topic of death. In The Wasteland T. S Eliot is describing death with a very different approach which makes death seem poetic yet very dreary and uninviting. On the other hand, in Yulisa Amadu Maddy's book No Past, No Present, No Future death is not poetic at all but very cold and melancholy. In No Past, No Present, No Future three boys become best friends and later their friendship is torn apart from the inside out until it finally dies. It began when Joe Bengoh came to live with Ade John and Santigie Bombalai after his parents died. That was the first death that Joe experienced. The second death affected both Joe and Ade when a girl Mary died. Mary was a prostitute who Joe lost his virginity to, and then afterwards Ade had sex with her. Mary claimed to be pregnant with Ade's child, and she committed suicide trying to abort the baby. Since Ade came from an elite and prestigious family his parents took him out of school and practically disowned him for disgracing their family name. That changed Ade's life from there on out because he was now alone and he wasn't going to let that mistake ruin all his dreams of becoming powerful and rich and wealthy. Joe was affected also by Mary's death because he held a deep sense of anger towards Ade for even having sex with the girl in front of him and later on down the road Mary's death has some part in tearing Joe and Ade apart. Santigie also experienced death, and that was the death of his father who was the chief of his tribe. That death hurt him deeply because when his father died, he left the position of chief not to Santigie but to his uncle. Also, when his father died, he had to quit school at the Mission and begin working like Ade had, because his mother couldn't afford to keep him in school anymore. When Santigie left the Mission Joe Bengoh was all alone and turned to things that shaped his future. Death in T.S. Eliot's The Wasteland and Maddy's No Past, No Present, No Future :: Death Eliot Maddy Wasteland Future Past Essays Death in T.S. Eliot's The Wasteland and Maddy's No Past, No Present, No Future Death is an inevitable fact that everyone experiences at some point in their lives. Whether it is losing a friend, family member, someone famous and well known, or finally themselves, everyone knows what it's like to deal with the topic of death. In The Wasteland T. S Eliot is describing death with a very different approach which makes death seem poetic yet very dreary and uninviting. On the other hand, in Yulisa Amadu Maddy's book No Past, No Present, No Future death is not poetic at all but very cold and melancholy. In No Past, No Present, No Future three boys become best friends and later their friendship is torn apart from the inside out until it finally dies. It began when Joe Bengoh came to live with Ade John and Santigie Bombalai after his parents died. That was the first death that Joe experienced. The second death affected both Joe and Ade when a girl Mary died. Mary was a prostitute who Joe lost his virginity to, and then afterwards Ade had sex with her. Mary claimed to be pregnant with Ade's child, and she committed suicide trying to abort the baby. Since Ade came from an elite and prestigious family his parents took him out of school and practically disowned him for disgracing their family name. That changed Ade's life from there on out because he was now alone and he wasn't going to let that mistake ruin all his dreams of becoming powerful and rich and wealthy. Joe was affected also by Mary's death because he held a deep sense of anger towards Ade for even having sex with the girl in front of him and later on down the road Mary's death has some part in tearing Joe and Ade apart. Santigie also experienced death, and that was the death of his father who was the chief of his tribe. That death hurt him deeply because when his father died, he left the position of chief not to Santigie but to his uncle. Also, when his father died, he had to quit school at the Mission and begin working like Ade had, because his mother couldn't afford to keep him in school anymore. When Santigie left the Mission Joe Bengoh was all alone and turned to things that shaped his future.

Social Effects of Technology Essay -- essays research papers

Introduction The interaction of technology and society may be the one thing more than any other that gives society a meaning and defines us a human beings. In recent years it has become popular to point fingers of accusation at technology as if it were "autonomous" and driving us all to perdition. I take other view. No doubt the uses of technology and society interact strongly. I think it wrongheaded and very naive to think of aggressive technology affecting a passive society eroding away the things that give society value and leaving behind a rusted hulk. Admittedly there always the potential for abuse or misuse of a technology, but technology is not inherently destructive, I argue. In the following we will consider ten effects of technology. No doubt many more can be thought of. Instead of, or in addition to the list below, we might include the effect of technology on health, on other technology or on the security of the individual and the nation. I consider these and other topics as too narrow in scope or able to be covered under one or more of the other headings. I believe the following ten can be used as a systematic first step into the study of technology and society. Here is the list of effects. Following that I will discuss each briefly. Finally I will present a list of nine values regarding the interaction of technology and society to guide our analysis. Ten Effects of Technology Technology's Effect on Commerce Technology's Effect on Social Systems Technology's Effect on The Environment Technology's Effect on Individual Psychology Technology's Effect on The Rate of Change Technology's Effect on Institutions Technology's Effect on Individual Freedom Technology's Effect on Our Perception of Reality Technology's Effect on Our Mutual Dependence Technology's Greatest Effect In the following each of these are briefly discussed. Technology's Effect on Commerce The first field deals with the economic and commercial consequences of the technology in question, whether it is an existing historical technology or a burgeoning one that is just beginning to impact the society. This was not chosen without considerable thought. The impact of technology on the commercial aspect of human culture is a major one. Most technological changes begin in the economic realm. Technology is a key factor in the supporting and developing of an... ... the argument that nature was created specifically for our use. There is pleasure and value for humans in nature. Preserving diversity preserves opportunities for pleasure. Ecologistic-Scientific values Humans enjoy the systematic study of nature. Esthetic Values Symbolic Values We use technology everyday -- in common speech, in literature, in art, in fact, in many ways for communication and thought. Humanistic Values Moralistic Values Dominionistic Values Humans seem to have a need to dominate nature. Generally one tries to preserve one's dominion. Negativistic Values This is the flip side of the positive values 1-8 above. This alludes to fear and alienation people feel toward some parts of nature such a spiders and snakes. Those who hold negative values may not support preservations attempts if they conflict with these values. Education plays a role -- a very strong role -- in the values a person holds. The more education one has received, the more one will tend to stress the importance of humanistic, moralistic and scientific values, downplaying dominionistic, utilitarian, and negativistic values. Those with less education tend to see things the other way around.

Research on Warehouse Design

European Journal of Operational Research 203 (2010) 539–549 Contents lists available at ScienceDirect European Journal of Operational Research journal homepage: www. elsevier. com/locate/ejor Invited Review Research on warehouse design and performance evaluation: A comprehensive review Jinxiang Gu a, Marc Goetschalckx b,*, Leon F. McGinnis b a b Nestle USA, 800 North Brand Blvd. , Glendale, CA 91203, United States Georgia Institute of Technology, 765 Ferst Dr. , Atlanta, GA 30332-0205, United States a r t i c l e i n f o a b s t r a c tThis paper presents a detailed survey of the research on warehouse design, performance evaluation, practical case studies, and computational support tools. This and an earlier survey on warehouse operation provide a comprehensive review of existing academic research results in the framework of a systematic classi? cation. Each research area within this framework is discussed, including the identi? cation of the limits of previous research and of potential future research directions. O 2009 Elsevier B. V. All rights reserved.Article history: Received 5 December 2005 Accepted 21 July 2009 Available online 6 August 2009 Keywords: Facilities design and planning Warehouse design Warehouse performance evaluation model Case studies Computational tools 1. Introduction This survey and a companion paper (Gu et al. , 2007) present a comprehensive review of the state-of-art of warehouse research. Whereas the latter focuses on warehouse operation problems related to the four major warehouse functions, i. e. , receiving, storage, order picking, and shipping, this paper concentrates on warehouse design, performance evaluation, case studies, and computational support tools.The objectives are to provide an all-inclusive overview of the available methodologies and tools for improving warehouse design practices and to identify potential future research directions. Warehouse design involves ? ve major decisions as illustrated in Fig. 1: deter mining the overall warehouse structure; sizing and dimensioning the warehouse and its departments; determining the detailed layout within each department; selecting warehouse equipment; and selecting operational strategies. The overall structure (or conceptual design) determines the material ? ow pattern within the warehouse, the speci? ation of functional departments, and the ? ow relationships between departments. The sizing and dimensioning decisions determine the size and dimension of the warehouse as well as the space allocation among various warehouse departments. Department layout is the detailed con? guration within a warehouse department, for example, aisle con? guration in the retrieval area, pallet block-stacking pattern in the reserve storage area, and con? guration of an Automated Storage/Retrieval System (AS/RS). The equipment selection deci* Corresponding author. Tel. : +1 404 894 2317; fax: +1 404 894 2301. E-mail address: marc. [email  protected] gatech. edu (M. G oetschalckx). 0377-2217/$ – see front matter O 2009 Elsevier B. V. All rights reserved. doi:10. 1016/j. ejor. 2009. 07. 031 sions determine an appropriate automation level for the warehouse, and identify equipment types for storage, transportation, order picking, and sorting. The selection of the operation strategy determines how the warehouse will be operated, for example, with regards to storage and order picking. Operation strategies refer to those decisions about operations that have global effects on other design decisions, and therefore need to be considered in the design phase.Examples of such operation strategies include the choice between randomized storage or dedicated storage, whether or not to do zone picking, and the choice between sort-while-pick or sortafter-pick. Detailed operational policies, such as how to batch and route the order picking tour, are not considered design problems and therefore are discussed in Gu et al. (2007). It should be emphasized that w arehouse design decisions are strongly coupled and it is dif? cult to de? ne a sharp boundary between them. Therefore, our proposed classi? ation should not be regarded as unique, nor does it imply that any of the decisions should be made independently. Furthermore, one should not ignore operational performance measures in the design phase since operational ef? ciency is strongly affected by the design decisions, but it can be very expensive or impossible to change the design decisions once the warehouse is actually built. Performance evaluation is important for both warehouse design and operation. Assessing the performance of a warehouse in terms of cost, throughput, space utilization, and service provides feedback about how a speci? design or operational policy performs compared with the requirements, and how it can be improved. Furthermore, a good performance evaluation model can help the designer to quickly evaluate many design alternatives and narrow down the design space durin g the early design stage. Performance operational cost for each alternative is estimated using simple analytic equations. Gray et al. (1992) address a similar problem, and propose a multi-stage hierarchical approach that uses simple calculations to evaluate the tradeoffs and prune the design space to a few superior alternatives.Simulation is then used to provide detailed performance evaluation of the resulting alternatives. Yoon and Sharp (1996) propose a structured approach for exploring the design space of order picking systems, which includes stages such as design information collection, design alternative development, and performance evaluation. In summary, published research ndco4h lar02. 8659(war,. 0320Td[(pro2k evaluation methods include benchmarking, analytical models, and simulation models.This review will mainly focus on the former two since simulation results depend greatly on the implementation details and are less amenable to generalization. However, this should not obs cure the fact that simulation is still the most widely used technique for warehouse performance evaluation in the academic literature as well as in practice. Some case studies and computational systems are also discussed in this paper. Research in these two directions is very limited. However, it is our belief that more case studies and computational tools for warehouse design and operation will help to bridge the signi? ant gap between academic research and practical application, and therefore, represent a key need for the future. The study presented in this paper and its companion paper on operations, Gu et al. (2007), complements previous surveys on warehouse research, for example, Cormier (2005), Cormier and Gunn (1992), van den Berg (1999) and Rowenhorst et al. (2000). Over 250 papers are included within our classi? cation scheme. To our knowledge, it is the most comprehensive review of existing research results on warehousing.However, we make no claim that it includes all the literature on warehousing. The scope of this survey has been mainly focused on results published in available English-language research journals. The topic of warehouse location, which is part of the larger area of distribution system design, is not addressed in this current review. A recent survey on warehouse location is provided by Daskin et al. (2005). The next four sections will discuss the literature on warehouse design, performance evaluation, case studies, and computational systems, respectively. The ? al section gives conclusions and future research directions. 2. Warehouse design 2. 1. Overall structure The overall structure (or conceptual design) of a warehouse determines the functional departments, e. g. , how many storage departments, employing what technologies, and how orders will be assembled. At this stage of design, the issues are to meet storage and throughput requirements, and to minimize costs, which may be the discounted value of investment and future operating costs. We can identify only three published papers addressing overall structural design.Park and Webster (1989) assume the functions are given, and select equipment types, storage rules, and order picking policies to minimize total costs. The initial investment cost and annual J. Gu et al. / European Journal of Operational Research 203 (2010) 539–549 541 Levy (1974), Cormier and Gunn (1996) and Goh et al. (2001) consider warehouse sizing problems in the case where the warehouse is responsible for controlling the inventory. Therefore, the costs in their models include not only warehouse construction cost, but also inventory holding and replenishment cost.Levy (1974) presents analytic models to determine the optimal storage size for a single product with either deterministic or stochastic demand. Assuming additional space can be leased to supplement the warehouse, Cormier and Gunn (1996) propose closed-form solution that yields the optimal warehouse size, the optimal amount of space to lease in each period, and the optimal replenishment quantity for a single product case with deterministic demand. The multi-product case is modeled as a nonlinear optimization problem assuming that the timing of replenishments is not managed.Cormier and Gunn (1999) developed a nonlinear programming formulation for the optimal warehouse expansion over consecutive time periods. Goh et al. (2001) ? nd the optimal storage size for both single-product and multi-product cases with deterministic demand. They consider a more realistic piecewise linear model for the warehouse construction cost instead of the traditional linear cost model. Furthermore, they consider the possibility of joint inventory replenishment for the multi-product case, and propose a heuristic to ? nd the warehouse size.The effects of inventory control policies (e. g. , the reorder point and ordering quantity) on the total required storage capacity are shown by Rosenblatt and Roll (1988) using simulation. Our a bility to answer warehouse sizing questions would be signi? cantly enhanced by two types of research. First, assessing capacity requirements should consider seasonality, storage policy, and order characteristics, because these three factors interact to impact the achievable storage ef? ciency, i. e. that fraction of warehouse capacity that can actually be used effectively.Second, sizing models all employ cost models, and validation studies of these models would be a signi? cant contribution. 2. 2. 2. Warehouse dimensioning The warehouse dimensioning problem translates capacity into ? oor space in order to assess construction and operating costs, and was ? rst modeled by Francis (1967), who used a continuous approximation of the storage area without considering aisle structure. Bassan et al. (1980) extends Francis (1967) by considering aisle con? gurations. Rosenblatt and Roll (1984) integrate the optimization model in Bassan et al. 1980) with a simulation model which evaluates the s torage shortage cost, a function of storage capacity and number of zones. They assume single-command tours in order to evaluate the effect of warehouse dimension on the operational cost, and therefore their approach is not applicable to warehouses that perform multi-command operations (e. g. , interleaving put-away and retrieval, or retrieving multiple items per trip). The work discussed so far has approached the sizing and dimensioning problem assuming the warehouse has a single storage department.In reality, a warehouse might have multiple departments, e. g. , a forward-reserve con? guration, or different storage departments for different classes of Stock Keeping Units (SKUs). These different departments must be arranged in a single warehouse and compete with each other for space. Therefore, there are tradeoffs in determining the total warehouse size, allocating the warehouse space among departments, and determining the dimension of the warehouse and its departments. Research stud ying these tradeoffs in the warehouse area is scarce.Pliskin and Dori (1982) propose a method to compare alternative space allocations among different warehouse departments based on multi-attribute value functions, which explicitly capture the tradeoffs among different criteria. Azadivar (1989) proposes an approach to optimally allocate space between two departments: one is ef? cient in terms of storage but inef? cient in terms of operation, while the other is the opposite. The objective is to achieve the best system performance by appropriately allocating space between these two departments to balance the storage capacity and operational ef? iency tradeoffs. Heragu et al. (2005) consider a warehouse with ? ve functional areas, i. e. , receiving, shipping, cross-docking, reserve, and forward. They propose an optimization model and a heuristic algorithm to determine the assignment of SKUs to the different storage areas as well as the size of each functional area to minimize the total material handling and storage costs. A key issue with all research on the dimensioning problem is that it requires performance models of material handling; these models are often independent of the size or layout of the warehouse.Research is needed to either validate these models, or develop design methods that explicitly consider the impact of sizing and dimensioning on material handling. 2. 3. Department layout In this section we discus layout problems within a warehouse department, primarily a storage department. The storage problems are classi? ed as: (P1) pallet block-stacking pattern, i. e. , storage lane depth, number of lanes for each depth, stack height, pallet placement angle with regards to the aisle, storage clearance between pallets, and length and width of aisles; (P2) storage department layout, i. . , door location, aisle orientation, length and width of aisles, and number of aisles; and (P3) AS/RS con? guration, i. e. , dimension of storage racks, number of cranes. These layout problems affect warehouse performances with respect to: (O1) construction and maintenance cost; (O2) material handling cost; (O3) storage capacity, e. g. , the ability to accommodate incoming shipments; (O4) space utilization; and (O5) equipment utilization. Each problem is treated in the literature by different authors considering a subset of the performance measures, as summarized in Table 1. 2. 3. 1.Pallet block-stacking pattern (P1) In the pallet block-stacking problem, a fundamental decision is the selection of lane depths to balance the tradeoffs between space utilization and ease of storage/retrieval operations, considering the SKUs’ stackability limits, arriving lot sizes, and retrieval patterns. Using deep lane storage could increase space utilization because fewer aisles are needed, but on the other hand could also cause decreased space utilization due to the ‘‘honeycombing† effect that creates unusable space for the storage of other i tems until the whole lane is totally depleted.The magnitude of the honeycombing effect depends on lane depths as well as the withdrawal rates of individual products. Therefore, it might be bene? cial to store different classes of products in different lane depths. A careful determination and coordination of the lane depths for different products is necessary in order to achieve the best storage space utilization. Besides lane con? guration, the pallet block-stacking problem also determines such decisions as aisle widths and orientation, stack height, and storage clearance, which all affect storage space utilization, material handling ef? iency, and storage capacity. 542 J. Gu et al. / European Journal of Operational Research 203 (2010) 539–549 Table 1 A summary of the literature on warehouse layout design. Problem P1 Citation Moder and Thornton (1965) Berry (1968) Marsh (1979) Marsh (1983) Goetschalckx and Ratliff (1991) Larson et al. (1997) Roberts and Reed (1972) Bassan et al. (1980) Rosenblatt and Roll (1984) Pandit and Palekar (1993) P3 Karasawa et al. (1980) Ashayeri et al. 1985) Rosenblatt et al. (1993) Objective O4 O2, O4 O3, O4 O4 O2, O4 O1, O2 O1, O2 O1, O2, O3 O2 O1, O2, O3 O1, O2 O1, O2, O3 O1, O5 O1, O5 O1 Method Analytical formulae Analytical formulae Simulation models Heuristic procedure Heuristic procedure Dynamic Programming Optimal design using analytical formulation Optimal two-dimensional search method Queuing model Nonlinear mixed integer problem Nonlinear mixed integer problem Nonlinear mixed integer problem NotesMainly on lane depth determination For class-based storage Consider the con? guration of storage bays (unit storage blocks) Consider horizontal and vertical aisle orientations, locations of doors, and zoning of the storage area Based on Bassan et al’s work with additional costs due to the use of grouped storage Include not only the ordinary travel time, but also waiting time when all vehicles are busy The model is so lved by generalized Lagrange multiplier method Given rack height, the model can be simpli? d to a convex problem System service is evaluated using simulations, if not satisfactory, new constraints are added and the optimization model is solved again to get a new solution A more elaborated variation of Zollinger’s rules that consider explicitly operational policies For the design of an automated carousel system. The model is solved with a simple search algorithm P2 Zollinger (1996) Malmborg (2001) Lee and Hwang (1988) Rule of thumb heuristic Rule of thumb heuristic Nonlinear integer program A number of papers discuss the pallet block-stacking problem.Moder and Thornton (1965) consider ways of stacking pallets in a warehouse and the in? uence on space utilization and ease of storage and retrieval. They consider such design factors as lane depth, pallet placement angle with regards to the aisle, and spacing between storage lanes. Berry (1968) discusses the tradeoffs between stor age ef? ciency and material handling costs by developing analytic models to evaluate the total warehouse volume and the average travel distance for a given storage space requirement.The factors considered include warehouse shape, number, length and orientation of aisles, lane depth, throughput rate, and number of SKUs contained in the warehouse. It should be noted that the models for total warehouse volume and models for average travel distance are not integrated, and the warehouse layout that maximizes storage ef? ciency is different from the one that minimizes travel distance. Marsh (1979) uses simulation to evaluate the effect on space utilization of alternate lane depths and the rules for assigning incoming shipments to lanes.Marsh (1983) compares the layout design developed by using the simulation models of Marsh (1979) and the analytic models proposed by Berry (1968). Goetschalckx and Ratliff (1991) develop an ef? cient dynamic programming algorithm to maximize space utilizati on by selecting lane depths out of a limited number of allowable depths and assigning incoming shipments to the different lane depths. Larson et al. (1997) propose a three-step heuristic for the layout problem of class-based pallet storage with the purpose to maximize storage space utilization and minimize material handling cost. The ? st phase determines the aisles layout and storage zone dimensions; the second phase assigns SKUs to storage con? gurations; and the third phase assigns ? oor space to the storage con? gurations. The research addressing the pallet block-stacking problem suggests different rules or algorithms, usually with restrictive assumptions, e. g. , the replenishment quantities and retrieval frequencies for each SKU are known. In reality, not only do these change dynamically, but the SKU set itself changes, and pallet block-stacking patterns that are optimized for current conditions may be far from optimum in the near future.Research is needed that will identify a robust solution in the face of dynamic uncertainty in the storage and retrieval requirements. 2. 3. 2. Storage department layout (P2) The storage department layout problem is to determine the aisle structure of a storage department in order to minimize the construction cost and material handling cost. The decisions usually include aisle orientations, number of aisles, length and width of aisles, and door locations.In order to evaluate operational costs, some assumptions are usually made about the storage and order picking policies; random storage and single-command order picking are the most common assumptions. By assuming a layout con? guration, or a small set of alternative con? gurations, models can be formulated to optimize each con? guration. Roberts and Reed (1972) assume storage space is available in units of identical bays. Bassan et al. (1980) consider a rectangular warehouse, and aisles that are either parallel or perpendicular to the longest walls.In addition, they also discuss the optimal door locations in the storage department, and the optimal layout when the storage area is divided into different zones. Roll and Rosenblatt (1983) extend Bassan et al. (1980) to include the additional cost due to the use of grouped storage policy. Pandit and Palekar (1993) minimize the expected response time of storage and/or retrieval requests using a queuing model to calculate the total response time including waiting and processing time for different types of layouts. With these response times, an optimization model is solved to ? nd the optimal storage space con? urations. Roodbergen and Vis (2006) present an optimization approach for selecting the number and length of aisles and the depot location so as to minimize the expected length of a picking tour. They developed models for both S-shaped tours and a largest gap policy, and concluded that the choice of routing policy could, in some cases, have a signi? cant impact on the size and layout of the department . The conclusion from Roodbergen and Vis (2006) is quite significant, since it calls into question the attempt to optimize storage department layout without knowing what the true material handling performance will be.There is a need for additional research that helps to identify the magnitude of the impact of layout (for reasonably shaped departments) on total costs over the life of the warehouse, considering changing storage and retrieval requirements. J. Gu et al. / European Journal of Operational Research 203 (2010) 539–549 543 2. 3. 3. AS/RS con? guration (P3) The AS/RS con? guration problem is to determine the numbers of cranes and aisles, and storage rack dimension in order to minimize construction, maintenance, and operational cost, and/or maximize equipment utilization.The optimal design models or rule-ofthumb procedures summarized in Table 1 typically utilize some empirical expressions of the costs based on simple assumptions for the operational policies, and known s torage and retrieval rates. Karasawa et al. (1980) present a nonlinear mixed integer formulation with decision variables being the number of cranes and the height and length of storage racks and costs including construction and equipment costs while satisfying service and storage capacity requirements. Ashayeri et al. 1985) solve a problem similar to Karasawa et al. (1980). Given the storage capacity requirement and the height of racks, their models can be simpli? ed to include only a single design variable, i. e. , the number of aisles. Furthermore, the objective function is shown to be convex in the number of aisles, which allows a simple one-dimensional search algorithm to optimally solve the problem. Rosenblatt et al. (1993) propose an optimization model that is a slight modi? cation of Ashayeri et al. (1985), which allows a crane to serve multiple aisles.A combined optimization and simulation approach is proposed, where the optimization model generates an initial design, and a simulation evaluates performance, e. g. , service level. If the constraints evaluated by simulation are satis? ed, then the procedure stops. Otherwise, the optimization model is altered by adding new constraints that have been constructed by approximating the simulation results. Zollinger (1996) proposes some rule of thumb heuristics for designing an AS/RS. The design criteria include the total equipment costs, S/ R machine utilization, service time, number of jobs waiting in the queue, and storage space requirements.Closed form equations compute these criteria as functions of the number of aisles and the number of levels in the storage rack. Malmborg (2001) uses simulation to re? ne the estimates of some of the parameters which then are used in the closed form equations. The design of automated carousel storage systems is addressed by Lee and Hwang (1988). They use an optimization approach to determine the optimal number of S/R machines and the optimal dimensions of the carousel sy stem to minimize the initial investment cost and operational costs over a ? ite planning horizon subject to constraints for throughput, storage capacity, and site restrictions. Some other less well-discussed AS/RS design problems include determining the size of the basic material handling unit and the con? guration of I/O points. Roll et al. (1989) propose a procedure to determine the single optimal container size in an AS/RS, which is the basic unit for storage and order picking. Container size has a direct effect on space utilization, and therefore on the equipment cost since the storage capacity requirement needs to be satis? ed. Randhawa et al. 1991) and Randhawa and Shroff (1995) use simulations to investigate different I/O con? gurations on performance such as throughput, mean waiting time, and maximum waiting time. The results indicate that increased system throughput can be achieved using I/O con? gurations different from the common one-dock layout where the dock is located at the end of the aisle. There are two important opportunities for additional research on AS/RS con? guration: (1) results for a much broader range of technology options, e. g. , double deep rack, multi-shuttle cranes, etc. ; and (2) results demonstrating the sensitivity of con? urations to changes in the expected storage and retrieval rates or the effects of a changing product mix. 2. 4. Equipment selection The equipment selection problem addresses the level of automation in a warehouse and what type of storage and material han- dling systems should be employed. These decisions obviously are strategic in nature in that they affect almost all the other decisions as well as the overall warehouse investment and performance. Determining the best level of automation is far from obvious in most cases, and in practice it is usually determined based on the personal experience of designers and managers.Academic research in this category is extremely rare. Cox (1986) provides a methodology t o evaluate different levels of automation based on a cost-productivity analysis technique called the hierarchy of productivity ratios. White et al. (1981) develop analytical models to compare block stacking, single-deep and doubledeep pallet rack, deep lane storage, and unit load AS/RS in order to determine the minimum space design. Matson and White (1981) extend White et al. (1981) to develop a total cost model incorporating both space and material handling costs, and demonstrate the effect of handling requirements on the optimum storage design.Sharp et al. (1994) compare several competing small part storage equipment types assuming different product sizes and dimensions. They considered shelving systems, modular drawers, gravity ? ow racks, carousel systems, and mini-load storage/retrieval systems. The costs they considered include operational costs, ? oor space costs, and equipment costs. In summary, research on equipment selection is quite limited and preliminary, although it is very important in the sense that it will affect the whole warehouse design and the overall lifetime costs.There are two fundamental issues for equipment selection: (1) how to identify the equipment alternatives that are reasonable for a given storage/retrieval requirement; and (2) how to select among the reasonable alternatives. A very signi? cant contribution would be to develop a method for characterizing requirements and characterizing equipment in such a way that these two issues could be addressed in a uni? ed manner. 2. 5. Operation strategy This section discusses the selection of operation strategies in a warehouse.The focus is on operation strategies that, once selected, have important effects on the overall system and are not likely to be changed frequently. Examples of such strategies are the decision between randomized and dedicated storage, or the decision to use zone picking. Two major operation strategies are discussed: the storage strategy and the order picking strat egy. Detailed operation policies and their implementations are discussed in Gu et al. (2007). 2. 5. 1. Storage The basic storage strategies include random storage, dedicated storage, class-based storage, and Duration-of-Stay (DOS) based storage, as explained in Gu et al. 2007). Hausman et al. (1976), Graves et al. (1977) and Schwarz et al. (1978) compare random storage, dedicated storage, and class-based storage in single-command and dual-command AS/RS using both analytical models and simulations. They show that signi? cant reductions in travel time are obtainable from dedicated storage compared with random storage, and also that class-based storage with relatively few classes yields travel time reductions that are close to those obtained by dedicated storage.Goetschalckx and Ratliff (1990) and Thonemann and Brandeau (1998) show theoretically that DOS-based storage policies are the most promising in terms of minimizing traveling costs. Historically, DOS-based policies were dif? cult to implement since they require the tracking and management of each stored unit in the warehouse, but modern WMS’s have this capability. Also the performance of DOS-based policies depends greatly on factors such as the skewness of demands, balance of input and output ? ows, inventory control policies, and the speci? cs of implementation. In a study by Kulturel et al. (1999), class-based 544 J. Gu et al. European Journal of Operational Research 203 (2010) 539–549 storage and DOS-based storage are compared using simulations, and the former is found to consistently outperform the latter. This conclusion may have been reached because the assumptions of the DOS model rarely hold true in practice. All the results on operational strategies are for unit-load AS/RS. Studies on other storage systems are rarely reported. Malmborg and Al-Tassan (1998) develop analytic models to evaluate the performance of dedicated storage and randomized storage in lessthan-unit-load warehouses, but no general conclusions comparable to the unit-load case are given.A strong case can be made that additional research is needed, especially to clarify the conditions under which the storage policy does or does not have a signi? cant impact on capacity or travel time. 2. 5. 2. Order picking In a given day or shift, a warehouse may have many orders to pick. These orders may be similar in a number of respects; for example, some orders are shipped using the same carrier, or transportation mode, or have the same pick due date and time.If there are similarities among subsets of orders that require them to be shipped together, then they also should be picked roughly during the same time period to avoid intermediate storage and staging. Thus, it is common practice to use wave picking, i. e. , to release a fraction of the day’s (shift’s) orders, and to expect their picking to be completed within a corresponding fraction of the day (shift). In addition to wave picking, two ot her commonly used orderpicking strategies are batch picking and zone picking.Batch picking involves the assignment of a group of orders to a picker to be picked simultaneously in one trip. In zone picking, the storage space is divided into picking zones and each zone has one or more assigned pickers who only pick in their assigned zone. Zone picking can be divided into sequential and parallel zone picking. Sequential zone picking is similar to a ? ow line, in which containers that can hold one or more orders are passed sequentially through the zones; the pickers in each zone pick the products within their zone, put them into the container, and then pass the container to the next zone. Bartholdi et al. (2000) propose a Bucket Brigades order picking method that is similar to sequential zone picking, but does not require pickers to be restricted to zones). In parallel zone picking, an order is picked in each zone simultaneously. The picked items are sent to a downstream sorting system to be combined into orders. The organization and planning of the order picking process has to answer the following questions: 1. Will product be transported to the picker (part-to-picker) or will the picker travel to the storage location (picker-to-part)? . Will orders be picked in waves? If so, how many waves of what duration? 3. Will the warehouse be divided into zones? If so, will zones be picked sequentially or concurrently? 4. Will orders be picked in batches or separately? If they are batched, will they be sorted while picking or after picking? Depending on the operating principles selected, the order picking methods will be:        Single order picking. Batching with sort-while-pick. Batching with sort-after-pick. Sequential zoning with single order picking. Sequential zoning with batching.Concurrent zoning without batching. Concurrent zoning with batching. Research on the selection of an order picking strategy is very scarce, which might be a result of the complexity of the problem itself. Lin and Lu (1999) compare single-order picking and batch zone picking for different types of orders, which are classi? ed based on the order quantity and the number of ordered items. Petersen (2000) simulates ? ve different order-picking policies: singleorder picking, batch picking, sequential zone picking, concurrent zone picking, and wave picking.Two control variables in the simulation study are the numbers of daily orders and the demand skewness, while the other factors such as warehouse layout, storage assignment, and zone con? guration (when zone and wave picking are used) are ? xed. The performance measures used to compare the different policies include: the mean daily labor, the mean length of day, and the mean percentage of late orders. For each order picking policy, the simplest rules regarding batching, routing, and wave length are used. It also should be noted that the performance measures are mainly related to order picking ef? iencies and service quality; additional costs caused by downstream sorting with batch, zone, and wave picking are not considered. Furthermore, comparison of these policies are made mainly with regards to the order structures, while other important factors such as storage assignment and detailed implementations of the order picking policies are assumed to be ? xed. Therefore, the results should not be considered generic and more research in this direction is required to provide more guidance for warehouse designers. Order picking strategy selection remains a largely unresolved design problem.Additional research would be valuable, especially if it could begin to characterize order picking alternatives in ways that were easy to apply in design decision making. As an example, could researchers develop performance curves for different order picking strategies? 3. Performance evaluation Performance evaluation provides feedback on the quality of a proposed design and/or operational policy, and more importantl y, on how to improve it. There are different approaches for performance evaluation: benchmarking, analytic models, and simulations. This section will only discuss benchmarking and analytic models. 3. 1.Benchmarking Warehouse benchmarking is the process of systematically assessing the performance of a warehouse, identifying inef? ciencies, and proposing improvements. Data Envelopment Analysis (DEA) is regarded as an appropriate tool for this task because of its capability to capture simultaneously all the relevant inputs (resources) and outputs (performances), to construct the best performance frontier, and to reveals the relative shortcomings of inef? cient warehouses. Schefczyk (1993), Hackman et al. (2001), and Ross and Droge (2002) shows some approaches and case studies of using DEA in warehouse benchmarking.An Internet-based DEA system (iDEAS) for warehouses is developed by the Keck Lab at Georgia Tech, which includes information on more than 200 warehouses (McGinnis, 2003). 3. 2. Analytical models Analytic performance models fall into two main categories: (1) aisle based models which focus on a single storage system and address travel or service time; and (2) integrated models which address either multiple storage systems or criteria in addition to travel/service times. J. Gu et al. / European Journal of Operational Research 203 (2010) 539–549 545 3. 2. 1.Aisle based models Table 2 summarizes research on travel time models for aislebased systems. A signi? cant fraction of research focuses on the expected travel time for the crane in an AS/RS, for either single command (SC) or dual command (DC) cycles. For both, there is research addressing three different storage policies: in randomized storage, any SKU can occupy any location; in dedicated storage, each SKU has a set of designated locations; and in class based storage, a group of storage locations is allocated to a class of SKUs, and randomized storage is allowed within the group of storage locati ons.The issue with DC cycles is matching up storages and retrievals to minimize the dead-head travel of the crane, which may involve sequencing retrievals, and selecting storage locations. The results in this category usually assume in? nite acceleration to simplify the travel time models, although some develop more elaborate models by considering acceleration for the various axes of motion (see, e. g. , Hwang and Lee, 1990; Hwang et al. , 2004b; Chang and Wen, 1997; Chang et al. , 1995).There are a few papers that attack the more mathematically challenging issue of deriving the distribution of travel time (see Foley and Frazelle (1991) and Foley et al. (2002)). The research on carousel travel time models generally parallels corresponding AS/RS research. Given some knowledge of travel time, AS/RS service time models can be developed, considering the times required for load/unload and store/retrieve at the storage slot. Queuing models have been developed assuming various distribution s for travel time, see e. g. Lee (1997), Chow (1986), Hur et al. (2004), Bozer and White (1984), Park et al. (2003a) for AS/RS, Chang et al. (1995) for conventional multi-aisle systems, and for end-of-aisle picking systems, see Bozer and White (1991, 1996), Park et al. (2003a), and Park et al. (1999). Stochastic optimization models have been developed for estimating AS/RS throughput, with constraints on storage queue length and retrieval request waiting time (Azadivar, 1986). The throughput of carousel systems is modeled by Park et al. (2003b) and Meller and Klote (2004).The former consider a system with two carousels and one picker, and derive analytic expressions for the system throughput and picker utilization assuming deterministic and exponential pick time distributions. Meller and Klote (2004) develop throughput models for systems with multiple carousels using an approximate two-server queuing model approach. For conventional multi-aisle storage systems (bin shelving, e. g. ), two kinds of travel time results have been developed: (1) models which estimate the expected travel time; and (2) models of the pdf of travel times.These models require an assumption about the structure of the tour, e. g. , traversal (Hall, 1993), return (Hall, 1993 or Caron et al. , 1998), or largest gap (Roodbergen and Vis, 2006). As long as these models are parameterized on attributes of the storage system design, they can be used to support design by searching over the relevant parameters. As with AS/RS and carousels, there has been research to incorporate travel time models into performance models. Chew and Table 2 Literature of travel time models for different warehouse systems. Randomized storage Unit-load AS/RS Single-command Hausman et al. 1976) Bozer and White (1984) Thonemann and Brandeau (1998) Kim and Seidmann (1990) Hwang and Ko (1988) Lee (1997) Hwang and Lee (1990) Chang et al. (1995) Chang and Wen (1997) Koh et al. (2002) Lee et al. (1999) Graves et al. (1977) Boze r and White (1984) Kim and Seidmann (1990) Hwang and Ko (1988) Lee (1997) Han et al. (1987) Hwang and Lee (1990) Chang et al. (1995) Chang and Wen (1997) Koh et al. (2002) Lee et al. (1999) Meller and Mungwattana (1997) Potrc et al. (2004) Hwang and Song (1993) Bozer and White (1990) Bozer and White (1996) Foley and Frazelle (1991) Park et al. 1999) Han and McGinnis (1986) Han et al. (1988) Su (1998) Hwang and Ha (1991) Hwang et al. (1999) Hall (1993) Jarvis and McDowell (1991) Chew and Tang (1999) Hwang et al. (2004a) Caron et al. (1998) Caron et al. (2000) Jarvis and McDowell (1991) Chew and Tang (1999) Hwang et al. (2004a) Park et al. (2003a) Dedicated storage Hausman et al. (1976) Thonemann and Brandeau (1998) Kim and Seidmann (1990) Class-based storage Hausman et al. (1976) Thonemann and Brandeau (1998) Rosenblatt and Eynan (1989) Eynan and Rosenblatt (1994) Kouvelis and Papanicolaou (1995) Kim and Seidmann (1990) Pan and Wang (1996) Ashayeri et al. 2002) Dual-command Graves et al. (1977) Kim and Seidmann (1990) Graves et al. (1977) Kouvelis and Papanicolaou (1995) Kim and Seidmann (1990) Pan and Wang (1996) Ashayeri et al. (2002) Multi-shuttle Man-on-board AS/RS End-of-aisle AS/RS Carousel and rotary racks Ha and Hwang (1994) Conventional multi-aisle system Jarvis and McDowell (1991) Chew and Tang (1999) Hwang et al. (2004a) 546 J. Gu et al. / European Journal of Operational Research 203 (2010) 539–549 Tang (1999) use their model of the travel time pdf to analyze order batching and storage allocation using a queuing model.Bhaskaran and Malmborg (1989) present a stochastic performance evaluation model for the service process in multi-aisle warehouses with an approximated distribution for the service time that depends on the batch size and the travel distance. de Koster (1994) develops queuing models to evaluate the performance of a warehouse that uses sequential zone picking where each bin is assigned to one or more orders and is transported using a conveyer. If a bin needs to be picked in a speci? c zone, it is transported to the corresponding pick station.After it is picked, it is then put on the conveyor to be sent to the next pick station. The proposed queuing network model evaluates performance measures such as system throughput, picker utilization, and the average number of bins in the system based on factors such as the speed and length of the conveyor, the number of picking stations, and the number of picks per station. Throughput analysis of sorting systems is addressed in Johnson and Meller (2002). They assume that the induction process is the bottleneck of the sorting process, and therefore governs the throughput of the sorting system.This model is later incorporated into a more comprehensive model in Russell and Meller (2003) that integrates order picking and sorting to balance the tradeoffs between picking and packing with different order batch sizes and wave lengths. Russell and Meller (2003) also demonstrate th e use of the proposed model in determining whether or not to automate the sorting process and in designing the sorting system. 3. 2. 2. Integrated models Integrated models combine travel time analysis and the service quality criteria with other performance measures, e. g. storage capacity, construction cost, and operational cost. Malmborg (1996) proposes an integrated performance evaluation model for a warehouse having a forward-reserve con? guration. The proposed model uses information about inventory management, forward-reserve space allocation, and storage layout to evaluate costs associated with: storage capacity and space shortage; inventory carrying, replenishing, and expediting; and order picking and internal replenishment for the forward area. Malmborg (2000) evaluates several performance measures for a twin-shuttle AS/RS.Malmborg and Al-Tassan (2000) present a mathematical model to estimated space requirements and order picking cycle times for less than unit load order pick ing systems that uses randomized storage. The inputs of the model include product parameters, equipment speci? cations, operational policies, and storage area con? gurations. Malmborg (2003) models the dependency of performance measures such as expected total system construction cost and throughput on factors such as the vehicle ? eet size, the number of lifts, and the storage rack con? gurations for warehouse systems that use rail guided vehicles.Table 3 A Summary of the literature on warehouse case studies. Citation Cormier and Kersey (1995) Yoon and Sharp (1995) Zeng et al. (2002) Kallina and Lynn (1976) Brynzer and Johansson (1995) Burkard et al. (1995) van Oudheusden et al. (1988) Dekker et al. (2004) Luxhoj and Skarpness (1986) Johnson and Lofgren (1994) Problems studied Conceptual design Analytic travel time and performance models of storage systems represent a major contribution to warehouse design related research, and a rich set of models is available. Yet despite this wea lth of prior results, there is no uni? d approach to travel time modeling or performance modeling for aisle based systems – every system and every set of assumptions leads to a different model. A signi? cant research contribution would be to present a uni? ed theory of travel time in aisle-based systems. 4. Case studies There are some published industrial case studies, which not only provide applications of the various design and operation methods in practical contexts, but more importantly, also identify possible future research challenges from the industrial point of view. Table 3 lists these case studies, identifying the problems and the types of warehouse they investigated.It is dif? cult to generalize from such a small set of speci? c cases, but one conclusion is that substantial bene? ts can achieved by appropriately designing and operating a warehouse, see for example Zeng et al. (2002), van Oudheusden et al. (1988), and Dekker et al. (2004). On the other hand, one mig ht conclude from these cases that there are few generic simple rules. As just one example, the COI-based storage location assignment rule proposed by Kallina and Lynn (1976) ignores many practical considerations, such as varying weights, item-dependent travel costs, or dependencies between items.Some of these complications have been addressed in the academic research (for example see Table 3 in Section 5. 2 of Gu et al. (2007)), but many others remain unexplored. What these cases illustrate is the gap between the assumption-restricted models in research publications and the complex reality of most warehouses. There is a signi? cant need for more industrial case studies, which will assist the warehouse research community in better understanding the real issues in warehouse design. In turn, research results that have been tested on more realistic data sets will have a more substantial impact on practice.A warehouse design problem classi? cation, such as we have proposed here, might be used to structure such future case studies. 5. Computational systems There are numerous commercial Warehouse Management Systems (WMS) available in the market, which basically help the warehouse manager to keep track of the products, orders, space, equipment, and human resources in a warehouse, and provide rules/algorithms for storage location assignment, order batching, pick routing, etc. Detailed review of these systems is beyond the scope of this paper.Instead, we focus on the academic research addressing computational systems for warehouse design. As previous sections show, research on various warehouse design and Type of warehouse A warehouse for perishable goods that requires Just-In-Time operations An order picking system A distribution center A distribution center Kitting systems that supply materials to assembly lines An AS/RS where a S/R machine can serve any aisle using a switching gangway A man-on-board AS/RS in an integrated steel mill A multi-aisle manual order picking system A distribution center A distribution centerConceptual design Storage location assignment; warehouse dimensioning; storage and order picking policies Storage location assignment using the COI rule Process ? ow; batching; zone picking; Vehicle routing Storage location assignment; batching; routing Storage and routing policies Manpower planning Simulation by decomposition J. Gu et al. / European Journal of Operational Research 203 (2010) 539–549 547 operation problems has been conducted for almost half a century, and as a result, a large number of methodologies, algorithms, and empirical studies have been generated.However, successful implementations of these academic results in current commercial WMS systems or in engineering design software are rare. The prototype systems discussed in this section might shed some light on how academic research results could be utilized to develop more sophisticated computer aided warehouse design and operation systems. Perlmann and Bai ley (1988) present computer-aided design software that allows a warehouse designer to quickly generate a set of conceptual design alternatives including building shape, equipment selection, and operational policy selection, and to select from among them the best one based on the speci? d design requirements. To our knowledge, this is the only research paper addressing computer aided warehouse design. There are several papers on the design of warehouse control systems. Linn and Wysk (1990) develop an expert system for AS/ RS control. A control policy determines decisions such as storage location assignment, which item to retrieve if multi-items for the same product are stored, storage and retrieval sequencing, and storage relocation.Several control rules are available for each decision and the control policy is constructed by selecting one individual rule for each decision in a coherent way based on dynamically changing system state variables such as demand levels and traf? c intensi ty. A similar AS/RS control system is proposed by Wang and Yih (1997) based on neural networks. Ito et al. (2002) propose an intelligent agent based system to model a warehouse, which is composed of three subsystems, i. e. , agent-based communication system, agent-based material handling system, and agent-based inventory planning and control system.The proposed agent-based system is used for the design and implementation of warehouse simulation models. Kim et al. (2002) present an agent based system for the control of a warehouse for cosmetic products. In addition to providing the communication function, the agents also make decisions regarding the operation of the warehouse entities they represented in a dynamic real-time fashion. The absence of research prototypes for computer aided warehouse design is particularly puzzling, given the rapid advancement in computing hardware and software over the past decade.Academic researchers have been at the forefront of computer aided design i n other disciplines, and particularly in developing computational models to support design decision making. Warehousing design, as a research domain, would appear to be ripe for this kind of contribution. 6. Conclusions and discussion We have attempted a thorough examination of the published research related to warehouse design, and classi? ed papers based on the main issues addressed. Fig. 1 shows the numbers of papers in each category; there were 50 papers directly addressing warehouse design decisions.There were an additional 50 papers on various analytic models of travel time or performance for speci? c storage systems or aggregates of storage systems. Benchmarking, case studies and other surveys account for 18 more papers. One clear conclusion is that warehouse design related research has focused on analysis, primarily of storage systems rather than synthesis. While this is somewhat surprising, an even more surprising observation is that only 10% of papers directly addressing w arehouse design decisions have a publication date of 2000 or later.Given the rapid development of computing hardware and solvers for optimization, simulation, and general mathematical problems, one might reasonably expect a more robust design-centric research literature. We conjecture two primary inhibiting factors: 1. The warehouse design decisions identi? ed in Fig. 1 are tightly coupled, and one cannot be analyzed or determined in isolation from the others. Yet, the models available are not uni? ed in any way and are not ‘‘interoperable†. A researcher addressing one decision would require a research infrastructure integrating all the other decisions.The scope and scale of this infrastructure appears too great a challenge for individual researchers. 2. To properly evaluate the impact of changing one of the design decisions requires estimating changes in the operation of the warehouse. Not only are future operating scenarios not speci? ed in detail, even if they w ere, the total warehouse performance assessment models, such as high ? delity simulations, are themselves a considerable development challenge. From this, we conclude that the most important future direction for the warehouse design research community is to ? d ways to overcome these two hurdles. Key to that, we believe, will be the emergence of standard representations of warehouse elements, and perhaps some research community based tools, such as open-source analysis and design models. Other avenues for important contributions include studies describing validated or applied design models, and practical case studies that demonstrate the potential bene? ts of applying academic research results to real problems, or in identifying the hidden challenges that prevent their successful implementation.Finally, both analytic and simulation models are proposed to solve warehouse problems and each has its respective advantages and disadvantages. Analytic models are usually design-oriented in the sense that they can explore many alternatives quickly to ? nd solutions, although they may not capture all the relevant details of the system. On the other hand, simulation models are usually analysis-oriented – they provide an assessment of a given design, but usually have limited capability for exploring the design space. There is an important need to integrate both approaches to achieve more ? exibility in analyzing warehouse problems.This is also pointed out by Ashayeri and Gelders (1985), and its applicability has been demonstrated by Rosenblatt and Roll (1984) and Rosenblatt et al. (1993). There is an enormous gap between the published warehouse research and the practice of warehouse design and operations. Cross fertilization between the groups of practitioners and researchers appears to be very limited. Effectively bridging this gap would improve the state-of-the-art in warehouse design methodology. Until such communication is established, the prospect of meaningfu l expansion and enhancement of warehouse design methodology appears limited.Warehousing is an essential component in any supply chain. In the USA, the value of wholesale trade inventories is approximately half a trillion dollars (BEA, 2008), and 2004 inventory carrying costs (interest, taxes, depreciation, insurance, obsolescence and warehousing) have been estimated at 332 billion dollars (Trunick, 2005). To date the research effort focusing on warehousing is a very small fraction of the overall supply chain research. There are many challenging research questions and problems that have not received any attention.The challenge for the academic research community is to focus on the integrated design and operation of warehouses, while the challenge for industrial practitioners is to provide realistic test cases. References Ashayeri, J. , Gelders, L. F. , 1985. Warehouse design optimization. European Journal of Operational Research 21, 285–294. 548 J. Gu et al. / European Journal of Operational Research 203 (2010) 539–549 Goh, M. , Ou, J. , Teo, C. -P. , 2001. Warehouse sizing to minimize inventory and storage costs. Naval Research Logistics 48 (4), 299–312. Graves, S. C. , Hausman, W. H. , Schwarz, L. B. 1977. Storage-retrieval interleaving in automatic warehousing systems. Management Science 23 (9), 935–945. Gray, A. E. , Karmarkar, U. S. , Seidmann, A. , 1992. Design and operation of an orderconsolidation warehouse: models and applications. European Journal of Operational Research 58, 14–36. Gu, J. X. , Goetschalckx, M. , McGinnis, L. F. , 2007. Research on warehouse operation: A comprehensive review. European Journal of Operational Research 177 (1), 1–21. Ha, J. -W. , Hwang, H. , 1994. Class-based storage assignment policy in carousel system. Computers and Industrial Engineering 26 (3), 489–499.Hackman, S. T. , Frazelle, E. H. , Grif? n, P. M. , Grif? n, S. O. , Vlasta, D. A. , 2001. Benchmarking warehouse and d istribution operations: An input–output approach. Journal of Productivity Analysis 16, 79–100. Hall, R. W. , 1993. Distance approximation for routing manual pickers in a warehouse. IIE Transactions 25 (4), 76–87. Han, M. H. , McGinnis, L. F. , 1986. Carousel Application for Work-in-process: Modelling and Analysis. Material Handling Research Center, Georgia Institute of Technology, Atlanta, Georgia. Han, M. H. , McGinnis, L. F. , Shieh, J. S. , White, J. A. , 1987.On sequencing retrievals in an automated storage/retrieval system. IIE Transactions 19 (1), 56–66. Han, M. H. , McGinnis, L. F. , White, J. A. , 1988. Analysis of rotary rack operation. Material Flow 4, 283–293. Hausman, W. H. , Schwarz, L. B. , Graves, S. C. , 1976. Optimal storage assignment in automatic warehousing systems. Management Science 22 (6), 629–638. Heragu, S. S. , Du, L. , Mantel, R. J. , Schuur, P. C. , 2005. Mathematical model for warehouse design and product allocat ion. International Journal of Production Research 43 (2), 327–338. Hung, M. S. , Fisk, C. J. , 1984.Economic sizing of warehouses – A linear programming approach. Computers and Operations Research 11 (1), 13–18. Hur, S. , Lee, Y. H. , Lim, S. Y. , Lee, M. H. , 2004. A performance estimating model for AS/ RS by M/G/1 queuing system. Computers and Industrial Engineering 46, 233– 241. Hwang, H. , Ha, J. -W. , 1991. Cycle time models for single/double carousel system. International Journal of Production Economics 25, 129–140. Hwang, H. , Ko, C. S. , 1988. A study on multi-aisle system served by a single storage/ retrieval machine. International Journal of Production Research 26 (11), 1727– 1737.Hwang, H. , Lee, S. B. , 1990. Travel-time models considering the operating characteristics of the storage and retrieval machine. International Journal of Production Research 28 (10), 1779–1789. Hwang, H. , Song, J. Y. , 1993. Sequencing picking op erations and travel time models for man-on-board storage and retrieval warehousing system. International Journal of Production Economics 29, 75–88. Hwang, H. , Kim, C. -S. , Ko, K. -H. , 1999. Performance analysis of carousel systems with double shuttle. Computers and Industrial Engineering 36, 473–485. Hwang, H. , Oh, Y. H. , Lee, Y. K. , 2004a.An evaluation of routing policies for orderpicking operations in low-level picker-to-part system. International Journal of Production Research 42 (18), 3873–3889. Hwang, H. , Song, Y. -K. , Kim, K. -H. , 2004b. The impacts of acceleration/deceleration on travel time models for carousel systems. Computers and Industrial Engineering 46, 253–265. Ito, T. , Abadi, J. , Mousavi, S. M. , 2002. Agent-based material handling and inventory planning in warehouse. Journal of Intelligent Manufacturing 13 (3), 201–210. Jarvis, J. M. , McDowell, E. D. , 1991. Optimal product layout in an order picking warehouse.IIE Trans actions 23 (1), 93–102. Johnson, M. E. , Lofgren, T. , 1994. Model decomposition speeds distribution center design. Interfaces 24 (5), 95–106. Johnson, M. E. , Meller, R. D. , 2002. Performance analysis of split-case sorting systems. Manufacturing & Service Operations Management 4 (4), 258–274. Kallina, C. , Lynn, J. , 1976. Application of the cube-per-order index rule for stock location in a distribution warehouse. Interfaces 7 (1), 37–46. Karasawa, Y. , Nakayama, H. , Dohi, S. , 1980. Trade-off analysis for optimal design of automated warehouses. International Journal of Systems Science 11 (5), 567– 576.Kim, J. , Seidmann, A. , 1990. A framework for the exact evaluation of expected cycle times in automated storage systems with full-turnover item allocation and random service requests. Computers and Industrial Engineering 18 (4), 601– 612. Kim, B. -I. , Graves, R. J. , Heragu, S. S. , Onge, A. S. , 2002. Intelligent agent modeling of an ind ustrial warehousing problem. IIE Transactions 34 (7), 601–612. Koh, S. G. , Kim, B. S. , Kim, B. N. , 2002. Travel time model for the warehousing system with a tower crane S/R machine. Computers and Industrial Engineering 43 (3), 495–507. Kouvelis, P. , Papanicolaou, V. 1995. Expected travel time and optimal boundary formulas for a two-class-based automated storage/retrieval system. International Journal of Production Research 33 (10), 2889–2905. Kulturel, S. , Ozdemirel, N. E. , Sepil, C. , Bozkurt, Z. , 1999. Experimental investigation of shared storage assignment policies in automated storage/retrieval systems. IIE Transactions 31 (8), 739–749. Larson, N. , March, H. , Kusiak, A. , 1997. A heuristic approach to warehouse layout with class-based storage. IIE Transactions 29, 337–348. Lee, H. S. , 1997. Performance analysis for automated storage and retrieval systems.IIE Transactions 29, 15–28. Lee, M. -K. , Hwang, H. , 1988. An approach in the design of a unit-load automated carousel storage system. Engineering Optimization 13,