Academic literature on the topic 'Operations resaerch'

The two companions scurry off when they hear a noise at the door. It was only a noise, but it was also a message, a bit of information producing panic: an interruption, a corruption, a rupture of communication. Was the noise really a message? Wasn’t it, rather, static, a parasite? Michael Serres, 1982. Since, ordinarily, channels have a certain amount of noise, and therefore a finite capacity, exact transmission is impossible. Claude Shannon, 1948. Reading Information At their most simplistic, there are two means for shifting information around – analogue and digital. Analogue movement depends on analogy to perform computations; it is continuous and the relationships between numbers are keyed as a continuous ordinal set. The digital set is discrete; moving one finger at a time results in a one-to-one correspondence. Nevertheless, analogue and digital are like the two companions in Serres’ tale. Each suffers the relationship of noise to information as internal rupture and external interference. In their examination of historical constructions of information, Hobart and Schiffman locate the noise of the analogue within its physical materials; they write, “All analogue machines harbour a certain amount of vagueness, known technically as ‘noise’. Which describes the disturbing influences of the machine’s physical materials on its calculations” (208). These “certain amounts of vagueness” are essential to Claude Shannon’s articulation of a theory for information transfer that forms the basis for this paper. In transforming the structures and materials through which it travels, information has left its traces in digital art installation. These traces are located in installation’s systems, structures and materials. The usefulness of information theory as a tool to understand these relationships has until recently been overlooked by a tradition of media art history that has grouped artworks according to the properties of the artwork and/or tied them into the histories of representation and perception in art theory. Throughout this essay I use the productive dual positioning of noise and information to address the errors and impurity inherent within the viewing experiences of digital installation. Information and Noise It is not hard to see why the fractured spaces of digital installation are haunted by histories of information science. In his 1948 essay “The Mathematical Theory of Communication” Claude Shannon developed a new model for communications technologies that articulated informational feedback processes. Discussions of information transmission through phone lines were occurring alongside the development of technology capable of computing multiple discrete and variable packets of information: that is, the digital computer. And, like art, information science remains concerned with the material spaces of transmission – whether conceptual, social or critical. In the context of art something is made to be seen, understood, viewed, or presented as a series of relationships that might be established between individuals, groups, environments, and sensations. Understood this way art is an aesthetic relationship between differing material bodies, images, representations, and spaces. It is an event. Shannon was adamant that information must not be confused with meaning. To increase efficiency he insisted that the message be separated from its components; in particular, those aspects that were predictable were not to be considered information (Hansen 79). The problem that Shannon had to contend with was noise. Unwanted and disruptive, noise became symbolic of the struggle to control the growth of systems. The more complex the system, the more noise needed to be addressed. Noise is both the material from which information is constructed, as well as being the matter which information resists. Weaver (Shannon’s first commentator) writes: In the process of being transmitted, it is unfortunately characteristic that certain things are added to the signal which were not intended by the information source. These unwanted additions may be distortions of sound (in telephony, for example) or static (in radio), or distortions in shape or shading of picture (television), or errors in transmission (telegraphy or facsimile), etc. All of these changes in the transmitted signal are called noise. (4). To enable more efficient message transmission, Shannon designed systems that repressed as much noise as possible, while also acknowledging that without some noise information could not be transmitted. Shannon’s conception of information meant that information would not change if the context changed. This was crucial if a general theory of information transmission was to be plausible and meant that a methodology for noise management could be foregrounded (Pask 123). Without meaning, information became a quantity, a yes or no decision, that Shannon called a “bit” (1). Shannon’s emphasis on separating signal or message from both predicability and external noise appeared to give information an identity where it could float free of a material substance and be treated independently of context. However, for this to occur information would have to become fixed and understood as an entity. Shannon went to pains to demonstrate that the separation of meaning and information was actually to enable the reverse. A fluidity of information and the possibilities for encoding it would mean that information, although measurable, did not have a finite form. Tied into the paradox of this equation is the crucial role of noise or error. In Shannon’s communication model information is not only complicit with noise; it is totally dependant upon it for understanding. Without noise, either encoded within the original message or present from sources outside the channel, information cannot get through. The model of sender-encoder-channel-signal (message)-decoder-receiver that Shannon constructed has an arrow inserting noise. Visually and schematically this noise is a disruption pointing up and inserting itself in the nice clean lines of the message. This does not mean that noise was a last minute consideration; rather noise was the very thing Shannon was working with (and against). It is present in every image we have of information. A source, message, transmitter, receiver and their attendant noises are all material infrastructures that serve to contextualise the information they transmit, receive, and disrupt. Figure 1. Claude Shannon “The Mathematical Theory of Communication” 1948. In his analytical discussion of the diagram, Shannon actually locates noise in two crucial places. The first position accorded noise is external, marked by the arrow that demonstrates how noise is introduced to the message channel whilst in transit. External noise confuses the purity of the message whilst equivocally adding new information. External noise has a particular materiality and enters the equation as unexplained variation and random error. This is disruptive presence rather than entropic coded pattern. Shannon offers this equivocal definition of noise to be everything that is outside the linear model of sender-channel-receiver; hence, anything can be noise if it enters a channel where it is unwelcome. Secondly, noise was defined as unpredictability or entropy found and encoded within the message itself. This for Shannon was an essential and, in some ways, positive role. Entropic forces invited continual reorganisation and (when engaging the laws of redundancy) assisted with the removal of repetition enabling faster message transmission (Shannon 48). Weaver calls this shifting relationship between entropy and message “equivocation” (11). Weaver identified equivocation as central to the manner in which noise and information operated. A process of equivocation identified the receiver’s knowledge. For Shannon, a process of equivocation mediated between useful information and noise, as both were “measured in the same units” (Hayles, Chaos 55). To eliminate noise completely is to sacrifice information. Information understood in this way is also about relationships between differing material bodies, representations, and spaces, connected together for the purposes of transmission. It, like the artwork, is an event. This would appear to suggest a correlation between information transmission and viewing in galleries. Far from it. Although, the contemporary information channel is essentially a tube with fixed walls, (it is still constrained by physical properties, bandwidth and so on) and despite the implicit spatialisation of information models, I am not proposing a direct correlation between information channels and installation spaces. This is because I am not interested in ‘reading’ the information of either environment. What I am suggesting is that both environments share this material of noise. Noise is present in four places. Firstly noise is within the media errors of transmission, and secondly, it is within the media of the installation, (neither of which are one way flows). Thirdly, the viewer or listener introduces noise as interference, and lastly, it is present in the very materials thorough which it travels. Noise layered on noise. Redundancy and Modulation So far in this paper I have discussed the relationship of information to noise. For the remainder, I want to address some particular processes or manifestations of noise in New Zealand artists’ collective, et al.’s maintenance of social solidarity–instance 5 (2006, exhibited as part of the SCAPE Biennal of Art in Public Space, Christchurch Art Gallery). The installation occupies a small alcove that is partially blocked by a military-style portable table stacked with newspapers. Inside the space are three grey wooden chairs, some headphones, and a modified data projection of Google Earth. It is not immediately clear if the viewer is allowed within the spaces of the alcove to listen to the headphones as monotonous voices fill the whole space intoning political, social, and religious platitudes. The headphones might be a tool to block out the noise. In the installation it is as if multiple messages have been sent but their source, channel, and transmitter are unintelligible to the receiver. All that is left is information divorced from meaning. As other works by et al. have demonstrated, social solidarity is not a fundamentalism with directed positions and singular leaders. For example, in rapture (2004) noise disrupts all presence as a portable shed quivers in response to underground nuclear explosions 40,000km away. In the fundamental practice (2005) the viewer is left attempting to decode the un-encoded, as again sound and large steel barriers control and determine only certain movements (see http://www.etal.name/ for some documentation of these projects) . maintenance of social solidarity–instance 5 is a development of the fundamental practice. To enter its spaces viewers slip around the table and find themselves extremely close to the projection screen. Despite the provision of copious media the viewer cannot control any aspect of the environment. On screen, and apparently integral to the Google Earth imagery, are five animated and imposing dark grey monolith forms. Because of their connection to the monotonous voices in the headphones, the monoliths seem to map the imposition of narrative, power, and force in various disputed territories. Like their sudden arrival in Kubrick’s 2001: A Space Odyssey (1968) it is the contradiction of the visibility and improbability of the monoliths that renders them believable. On the video landscape the five monoliths apparently house the dispassionate voices of many different media and political authorities. Their presence is both redundant and essential as they modulate the layering of media forces – and in between, error slips in. In a broad discussion of information Gilles Deleuze and Felix Guattari highlight the necessary role of redundancy commenting that: redundancy has two forms, frequency and resonance; the first concerns the significance of information, the second (I=I) concerns the subjectivity of communication. It becomes apparent that information and communication, and even significance and subjectification, are subordinate to redundancy (79). In maintenance of social solidarity–instance 5 patterns of frequency highlight the necessary role of entropy where it is coded into gaps in the vocal transmission. Frequency is a structuring of information tied to meaningful communication. Resonance, like the stack of un-decodable newspapers on the portable table, is the carrier of redundancy. It is in the gaps between the recorded voices that connections between the monoliths and the texts are made, and these two forms of redundancy emerge. As Shannon says, redundancy is a problem of language. This is because redundancy and modulation do not equate with relationship of signal to noise. Signal to noise is a representational relationship; frequency and resonance are not representational but relational. This means that an image that might be “real-time” interrupts our understanding that the real comes first with representation always trailing second (Virilio 65). In maintenance of social solidarity–instance 5 the monoliths occupy a fixed spatial ground, imposed over the shifting navigation of Google Earth (this is not to mistake Google Earth with the ‘real’ earth). Together they form a visual counterpoint to the texts reciting in the viewer’s ears, which themselves might present as real but again, they aren’t. As Shannon contended, information cannot be tied to meaning. Instead, in the race for authority and thus authenticity we find interlopers, noisy digital images that suggest the presence of real-time perception. The spaces of maintenance of social solidarity–instance 5 meld representation and information together through the materiality of noise. And across all the different modalities employed, the appearance of noise is not through formation, but through error, accident, or surprise. This is the last step in a movement away from the mimetic obedience of information and its adherence to meaning-making or representational systems. In maintenance of social solidarity–instance 5 we are forced to align real time with virtual spaces and suspend our disbelief in the temporal truths that we see on the screen before us. This brief introduction to the work has returned us to the relationship between analogue and digital materials. Signal to noise is an analogue relationship of presence and absence. No signal equals a break in transmission. On the other hand, a digital system, due to its basis in discrete bits, transmits through probability (that is, the transmission occurs through pattern and randomness, rather than presence and absence (Hayles, How We Became 25). In his use of Shannon’s theory for the study of information transmission, Schwartz comments that the shift in information theory from analogue to digital is a shift from an analogue relationship of signal to noise to one of the probability of error (318). As I have argued in this paper, if it is measured as a quantity, noise is productive; it adds information. In both digital and analogue systems it is predictability and repetition that do not contribute information. Von Neumann makes the distinction clear saying that to some extent the “precision” of the digital machine “is absolute.” Even though, error as a matter of normal operation and not solely … as an accident attributable to some definite breakdown, nevertheless creeps in (294). Error creeps in. In maintenance of social solidarity–instance 5, et al. disrupts signal transmission by layering ambiguities into the installation. Gaps are left for viewers to introduce misreadings of scale, space, and apprehension. Rather than selecting meaning out of information within nontechnical contexts, a viewer finds herself in the same sphere as information. Noise imbricates both information and viewer within a larger open system. When asked about the relationship with the viewer in her work, et al. collaborator p.mule writes: To answer the 1st question, communication is important, clarity of concept. To answer the 2nd question, we are all receivers of information, how we process is individual. To answer the 3rd question, the work is accessible if you receive the information. But the question remains: how do we receive the information? In maintenance of social solidarity–instance 5 the system dominates. Despite the use of sound engineering and sophisticated Google Earth mapping technologies, the work appears to be constructed from discarded technologies both analogue and digital. The ominous hovering monoliths suggest answers: that somewhere within this work are methodologies to confront the materialising forces of digital error. To don the headphones is to invite a position that operates as a filtering of power. The parameters for this power are in a constant state of flux. This means that whilst mapping these forces the work does not locate them. Sound is encountered and constructed. Furthermore, the work does not oppose digital and analogue, for as von Neumann comments “the real importance of the digital procedure lies in its ability to reduce the computational noise level to an extent which is completely unobtainable by any other (analogy) procedure” (295). maintenance of social solidarity–instance 5 shows how digital and analogue come together through the productive errors of modulation and redundancy. et al.’s research constantly turns to representational and meaning making systems. As one instance, maintenance of social solidarity–instance 5 demonstrates how the digital has challenged the logics of the binary in the traditions of information theory. Digital logics are modulated by redundancies and accidents. In maintenance of social solidarity–instance 5 it is not possible to have information without noise. If, as I have argued here, digital installation operates between noise and information, then, in a constant disruption of the legacies of representation, immersion, and interaction, it is possible to open up material languages for the digital. Furthermore, an engagement with noise and error results in a blurring of the structures of information, generating a position from which we can discuss the viewer as immersed within the system – not as receiver or meaning making actant, but as an essential material within the open system of the artwork. References Barr, Jim, and Mary Barr. “L. Budd et al.” Toi Toi Toi: Three Generations of Artists from New Zealand. Ed. Rene Block. Kassel: Museum Fridericianum, 1999. 123. Burke, Gregory, and Natasha Conland, eds. et al. the fundamental practice. Wellington: Creative New Zealand, 2005. Burke, Gregory, and Natasha Conland, eds. Venice Document. et al. the fundamental practice. Wellington: Creative New Zealand, 2006. Daly-Peoples, John. Urban Myths and the et al. Legend. 21 Aug. 2004. The Big Idea (reprint) http://www.thebigidea.co.nz/print.php?sid=2234>. Deleuze, Gilles, and Felix Guattari. A Thousand Plateaus: Capitalism and Schizophrenia. Trans. Brian Massumi. London: The Athlone Press, 1996. Hansen, Mark. New Philosophy for New Media. Cambridge, MA and London: MIT Press, 2004. Hayles, N. Katherine. How We Became Posthuman: Virtual Bodies in Cybernetics, Literature and Informatics. Chicago and London: U of Chicago P, 1999. Hayles, N. Katherine. Chaos Bound: Orderly Disorder in Contemporary Literature and Science. Ithaca and London: Cornell University, 1990. Hobart, Michael, and Zachary Schiffman. Information Ages: Literacy, Numeracy, and the Computer Revolution. Baltimore: Johns Hopkins UP, 1998. p.mule, et al. 2007. 2 Jul. 2007 http://www.etal.name/index.htm>. Pask, Gordon. An Approach to Cybernetics. London: Hutchinson, 1961. Paulson, William. The Noise of Culture: Literary Texts in a World of Information. Ithaca and London: Cornell University, 1988. Schwartz, Mischa. Information Transmission, Modulation, and Noise: A Unified Approach to Communication Systems. 3rd ed. New York: McGraw-Hill, 1980. Serres, Michel. The Parasite. Trans. Lawrence R. Schehr. Baltimore: John Hopkins UP, 1982. Shannon, Claude. A Mathematical Theory of Communication. July, October 1948. Online PDF. 27: 379-423, 623-656 (reprinted with corrections). 13 Jul. 2004 http://cm.bell-labs.com/cm/ms/what/shannonday/paper.html>. Virilio, Paul. The Vision Machine. Trans. Julie Rose. Bloomington and Indianapolis: Indiana UP, British Film Institute, 1994. Von Neumann, John. “The General and Logical Theory of Automata.” Collected Works. Ed. A. H. Taub. Vol. 5. Oxford: Pergamon Press, 1963. Weaver, Warren. “Recent Contributions to the Mathematical Theory of Communication.” The Mathematical Theory of Commnunication. Eds. Claude Shannon and Warren Weaver. paperback, 1963 ed. Urbana and Chicago: U of Illinois P, 1949. 1-16. Work Discussed et al. maintenance of social solidarity–instance 5 2006. Installation, Google Earth feed, newspapers, sound. Exhibited in SCAPE 2006 Biennial of Art in Public Space Christchurch Art Gallery, Christchurch, September 30-November 12. Images reproduced with the permission of et al. Photographs by Lee Cunliffe. Acknowledgments Research for this paper was conducted with the support of an Otago Polytechnic Resaerch Grant. Photographs of et al. maintenance of social solidarity–instance 5 by Lee Cunliffe. Citation reference for this article MLA Style Ballard, Su. "Information, Noise and et al." M/C Journal 10.5 (2007). echo date('d M. Y'); ?> <http://journal.media-culture.org.au/0710/02-ballard.php>. APA Style Ballard, S. (Oct. 2007) "Information, Noise and et al.," M/C Journal, 10(5). Retrieved echo date('d M. Y'); ?> from <http://journal.media-culture.org.au/0710/02-ballard.php>.

Dans un contexte de crise climatique et de régulations du transport aérien, les transports publics ou les trains sont amenés à remplacer les véhicules privés et les vols court-courriers pour accéder aux aéroports. Afin de garantir aux passagers des trajets porte-à-porte fiables, il est alors nécessaire d'assurer une coordination entre les modes de transport aérien et terrestre. Cette intégration est essentielle notamment en cas de perturbations, telles qu'une panne de métro ou de train, induisant un risque pour les passagers d'arriver en retard à l'aéroport et éventuellement de manquer leur vol. Dans le cadre du projet européen TRANSIT, dédié au développement de mécanismes de coordination entre acteurs du transport aérien et terrestre basés sur le partage d'informations, nous proposons dans cette thèse des solutions pouvant être mises en œuvre au niveau de l'aéroport pour limiter l'impact de perturbations sur l'accès de l'aéroport pour les passagers. Supposant un échange d'informations en temps réel entre les opérateurs de transport aérien et terrestre, nous proposons des ajustements tactiques des opérations aéroportuaires afin d'améliorer l'expérience globale du passager. Cette thèse présente différentes contributions. Tout d'abord, nous avons développé un cadre de modélisation d'un aéroport et de son flux de passagers associé. Nous y présentons également une distribution de probabilité paramétrique appropriée pour modéliser le profil d'arrivée des passagers d'un vol en fonction de ses caractéristiques, permettant de reconstruire le flux d'arrivée des passagers à un aéroport à partir d'un planning de vol. Dans un deuxième temps, nous proposons deux stratégies pour les opérateurs aéroportuaires afin d'atténuer l'impact des perturbations sur les passagers. Ces deux stratégies sont basées sur des méthodes de Recherche Opérationnelle, faisant appel à des modèles mathématiques et des résolutions algorithmiques pour aider à la prise de décision. La première stratégie consiste en une réaffectation tactique des équipes de sécurité afin de réduire les temps d'attente des passagers aux points de contrôles de sûreté. Nous proposons deux formulations du problème, incluant ou non une ségrégation des flux de passagers pour traiter les passagers impactés par la perturbation dans une file d'attente séparée. La seconde stratégie consiste en une replanification tactique des vols pour attendre les passagers retardés tout en tenant compte des contraintes opérationnelles côté piste et des passagers en correspondance. Plusieurs approches de résolutions sont mises en place et comparées pour résoudre les différents problèmes d'optimisation. Ces méthodes reposent sur de la PLNE, un recuit simulé ou encore des heuristiques gloutonnes. Nous proposons également une approche par fenêtre de temps glissante pour mettre en œuvre ces stratégies en tenant compte des aspects opérationnels et de la disponibilité des données passagers. Nous testons les deux stratégies sur différents scénarios de perturbation afin de mieux comprendre et d'évaluer les bénéfices de ces solutions pour les passagers. Enfin, nous étendons la recherche au-delà des modèles théoriques à des applications pratiques. Premièrement, nous proposons une intégration de la stratégie de réaffectation des équipes de sûreté avec de la simulation à événement discret pour fournir une évaluation plus réaliste et établir la base d'un système d'aide à la décision pour les opérateurs aéroportuaires. Nous élargissons également le champ d'application de la replanification des vols au niveau du réseau air-rail, permettant une prise en compte de la propagation des retards et de son impact sur l'ensemble du réseau de transport. Cette extension permet une évaluation des retards des passagers à leur destination finale et l'évaluation de la pertinence d'une replanification tactique des vols pour les passagers
In light of the climate crisis and air transportation regulations, there is a growing interest in using public transportation or trains to replace cars and short-haul flights to access hub airports. In order to ensure passengers with reliable door-to-door journeys, seamless integration between air and ground transport modes is required. This integration is essential, especially during disruptions such as train or subway shutdowns, which significantly increase the risk of passengers arriving late and missing their flights. As part of the European TRANSIT project, dedicated to developing coordination mechanisms between air and ground transport operations based on information sharing, we propose solutions that can be implemented at the airport level to deal with airport access mode disruptions. Assuming real-time information sharing between air and ground transport stakeholders, our approach involves tactical adjustments in airport operations to enhance the overall passenger experience. Our work presents different contributions. Firstly, we propose a comprehensive framework for airport and passenger flow modelling. We also present the finding of a suitable parametric distribution for modelling the passenger arrival profile of a flight based on its characteristics, allowing for a reconstruction of passenger arrival flow at the airport entrance based on a flight schedule. Secondly, we propose two recovery strategies for airport operators to mitigate the impact of disruptions on passengers. Both strategies are grounded in Operations Research, employing mathematical modelling and algorithmic solving approaches to help decision-making. The first strategy is a tactical reallocation of security teams to reduce passenger waiting times at security screening checkpoints. We propose two problem formulations: whether or not to consider passenger flow segregation to handle disrupted passengers in a dedicated fast-track lane. The second recovery strategy is a tactical flight rescheduling to wait for delayed passengers while considering airside operational constraints and air-connecting passengers. We propose different approaches for solving the related optimization problems, namely ILP-solving, simulated annealing and greedy heuristic approaches and compare their effectiveness. We also propose a sliding-time window approach to implement such recovery strategies when dealing with operational aspects and data availability. We test both recovery strategies on a benchmark of disruption scenarios to gain insights and evaluate the benefits of such disruption management solutions for passengers. Finally, we extend the research beyond theoretical models to practical applications. First, we combine the security team reallocation strategy with discrete simulation tools to provide realistic assessments and the basis of a decision support system for airport operators. Secondly, we broaden the scope of flight rescheduling to the air-rail network level, capturing delay propagation and its impact on the overall transportation network. This extension allows for a comprehensive evaluation of passenger delays at their final destinations and an assessment of the benefits obtained for passengers through a tactical flight rescheduling adjustment

碩士
國立中央大學
企業管理學系在職專班
103
The development of Information Technology (IT) is one of the contributing factors for the fast growth of human knowledge and global economy. IT has been applied widely in diverse fields, including business management and different human activities. The use of IT is found in many modern medical services, ranging from routine medical affairs administration to medical quality and safety control. In this case study, a system developed by a company in manufacturing and sales of Chinese medicines is investigated. In order to increase the efficiency of its logistics system, the company uses barcode IT on its pharmaceutical products to facilitate identification, warehousing and logistics operations. The company develops the Electric Barcode Check System on the basis of their experiences and customer’s requirements for the purposes of increasing pharmaceutical quality, creating additional values for customers and maintaining customer’s loyalty. Because the number of the frequently used Chinese medicine items are more than 500, and some of their names, appearances or natures may be similar, making mistakes in the pharmaceutical operations is likely, which, in turn, may risk the patient’s life, leading to heavy burdens for the medical personnel. Therefore, the Electric Barcode Check System is used to scan the barcodes on the labels affixed on the pharmaceutical products to ensure correct operations. A digital scale is used and connected to the system to measure the weights of pharmaceutical products. The system can also perform inventory control to assist the management of core operations of Chinese medicine drugstores. However, does the Electric Barcode Check System satisfy the requirements of the customers? Are the value of the system and the required costs for its installation and operation acceptable? The system has not been well accepted after its launch. Then, is there any perceptual gap between the company investigated and its customers? In order to know whether the system creates added values for the customers, a series of researches are conducted on the basis of theories related to customer values, and the value chain connecting the system engineers, salesmen and customers is investigated. The purpose of the case study is to verify the added values created by the system and identify the perceptual gap between the company investigated and their customers for the value of the system, so to provide recommendation for optimizing the system. The pharmaceutical safety is one of the major concerns for health authorities and medical sectors. It is found the customers will increase their reliance on the Electric Barcode Check System after a period of adaption. The company in the case study should find out the obstacles for their sales of the system, such as the prices and after services. The marketing strategy should be flexible, making good use of IT on the customer services to create additional values and competition advantages for the customers for win-win results. Keywords: Barcode; Customer Value; Electric Barcode Check System; Value Chain.