Amusement parks are a huge business. Guest experiences determine the success or failure for an amusement park. This report suggests an approach to improve guest experience by managing guest flow. The guest happiness optimization problem is formulated into a visitor routing management model. The constraints for this model include attraction attributes and guest behavior. To build the attraction constraints, their information is first gathered from internet, field studies and surveys, and then input into simulation software. Constraints on guest behavior are set up with a literature study and a guest survey. A two phase heuristic is developed to solve this problem with constraints. Candidate routes are generated with a route construction algorithm in the first phase. Visitor distribution and selection on these candidate routes are determined in the second phase using a mixed integer programming solver. Visitor routes are then recommended to the park’s operator side, for them to distribute to guests visiting on their vacations. Data from Disney Epcot are collected and applied in the case study to implement the methodology in this report. Attraction operations capability is maintained at the current level with no additional cost for the project, while guest satisfaction is improved by ensuring the number and type of attractions they visit. In addition, average waiting time for visitors is reduced by at least 70% in the recommended operation strategy. / text

Cognitive Science is an interdisciplinary field that ties together the curricula of liberal arts and technical fields of study. However, it is de-emphasized in technical undergraduate studies such as Engineering. Cognitive Science is essentially the study of the human mind and how humans process information. It is the study of human responses, thinking, and perception. Human behavior and a person’s reaction are undetermined, but it can be better understood. Although human behavior and interaction is a routine part of life, engineers are taught to decipher code and not how to decipher a human’s behavior. Cognitive Science affects all aspects in the work environment. Organizational practices can be improved by understanding common biases and motivational theories in people. Having a cognitive awareness of typical human behavior will help to promote improved communication and positive reactions from people in the workplace. Human behavior is inevitable in any field but more crucial in technical fields especially when there is lack of communication or ambiguous guidelines and definitions. In technical fields, miscommunication or ambiguity can be a matter of life or death. In many situations, miscommunication can drive ambiguity. Although some people are happy with flexible guidelines, others seek to have well defined expectations. How do people react in situations surrounding miscommunication or ambiguity? In both situations, some people create opportunities and others become a hindrance. Processes and procedures can be put in place to alleviate ambiguous situations, but human performance and psychological factors still play a role as well. Human error can result from psychological factors, but the environment can be improved to limit those factors. As with any situation, mishaps are still prone to happen. Although human error is preventable in most cases, it’s never completely unavoidable. Human error continues to be a deep-rooted cause that can lead to negative outcomes. As stated by Alexander Pope, “to err is human…” (Moncur). This paper will explore underlying human behavior in daily activities. By understanding common biases and motivational theories driving human behavior, one can address negative behavior in a technical field in order to create opportunities. / text

Στην εργασία αυτή αντιμετωπίζεται το πρόβλημα της χωροθέτησης εγκαταστάσεων και της κατανομής της ζήτησης σε περιφερειακό επίπεδο μέσω της παρουσίασης σχετικών μαθηματικών υποδειγμάτων μικτού ακέραιου προγραμματισμού, τα οποία στη συνέχεια εφαρμόζονται σε περιπτωσιολογική μελέτη. Η εργασία αφορά την χωροθέτηση δημοσίων εγκαταστάσεων. Ειδικότερα, αναφέρεται στην κατηγορία των προβλημάτων χωροθέτησης που χρησιμοποιούν την τυπική συνάρτηση αποδοτικότητας minsum. Σε αυτές τις περιπτώσεις οι εγκαταστάσεις τοποθετούνται έτσι ώστε να ελαχιστοποιούν το άθροισμα του συνολικού κόστους μεταφοράς. Η εργασία επικεντρώνεται στην χωροθέτηση οχληρών εγκαταστάσεων και συγκεκριμένα στη χωροθέτηση εγκαταστάσεων διαχείρισης αστικών απορριμμάτων. Αυτές οι εγκαταστάσεις ασκούν επιδράσεις όχι μόνο στον χώρο που καταλαμβάνουν, αλλά και σε μεγάλες εκτάσεις γύρω τους. Το πρόβλημα χωροθέτησης σε αυτές τις περιπτώσεις γίνεται ακόμα πιο πολύπλοκο λόγω της αναγκαίας συνεκτίμησης πολλαπλών κριτηρίων. Για τον σκοπό αυτό αναπτύσσεται ένα εξειδικευμένο πλαίσιο παραγωγής μαθηματικών υποδειγμάτων. Ειδικότερα,. στην παρούσα διδακτορική εργασία, δημιουργήθηκαν μαθηματικά υποδείγματα βελτιστοποίησης μικτού ακέραιου προγραμματισμού, τα οποία στη συνέχεια αναλύονται με μεθόδους πολυκριτηριακής ανάλυσης. Τα υποδείγματα αυτά εφαρμόζονται σε περιπτωσιολογική μελέτη με θέμα το χωροθετικό σχεδιασμό ενός περιφερειακού συστήματος διαχείρισης των αστικών απορριμμάτων για τον νομό Αχαΐας. / This study considers a facility location problem with demand allocation in regional level through mixed integer programming models that have been developed for these propose. Afterwards, these models applied in a case study. The present research concerns mostly the public facility location problems. In particular, the PhD dissertation deals with models using the typical mathematical function of efficiency minsum. Therese models locate the facilities in order to minimize the sum of costs for opening facilities and variable transportation costs. The problem becomes more complicated if, in addition it is necessary to locate undesirable facilities. The selection of proper sites for the facilities with obnoxious characteristics is a sensitive issue that has often cause social and political tension. The multiobjective nature of the problem implies that a number of environmental social and political criteria have to be considered. The study presents a model generating framework for formulating location allocation models that applied in municipal solid waste management systems. These models analyzed via multicriteria methodology in order to select the locations of different types of facilities at the regional level. Finally, we apply these concepts in a case study for the development of a solid waste management system for a specific region in Greece.

This thesis focus on memory-aware algorithms tailored for hierarchical memory architectures, found for instance within multicore processors. We first study the matrix product on multicore architectures. We model such a processor, and derive lower bounds on the communication volume. We introduce three ad hoc algorithms, and experimentally assess their performance.We then target a more complex operation: the QR factorization of tall matrices. We revisit existing algorithms to better exploit the parallelism of multicore processors. We thus study the critical paths of many algorithms, prove some of them to be asymptotically optimal, and assess their performance.In the next study, we focus on scheduling streaming applications onto a heterogeneous multicore platform, the QS 22. We introduce a model of the platform and use steady-state scheduling techniques so as to maximize the throughput. We present a mixed integer programming approach that computes an optimal solution, and propose simpler heuristics. We then focus on minimizing the amount of required memory for tree-shaped workflows, and target a classical two-level memory system. I/O represent transfers from a memory to the other. We propose a new exact algorithm, and show that there exist trees where postorder traversals are arbitrarily bad. We then study the problem of minimizing the I/O volume for a given memory, show that it is NP-hard, and provide a set of heuristics.Finally, we compare archival policies for BLUE WATERS. We introduce two archival policies and adapt the well known RAIT strategy. We provide a model of the tape storage platform, and use it to assess the performance of the three policies through simulation.

This thesis deals with the mapping and the scheduling of workflows. In this context, we consider unreliable platforms, with processors subject to failures. In a first part, we consider a particular model of streaming applications : the filtering services. In this context, we aim at minimizing period and latency. We first neglect communication costs. In this model, we study scheduling problems on homogeneous and heterogeneous platforms. Then, the impact of communication costs on scheduling problems of a filtering application is studied. Finally, we consider the scheduling problem of such an application on a chain of processors. The theoretical complexity of any variant of this problem is proved. This filtering property can model the reliability of processors. The results of some computations are successfully computed, and some other ones are lost. We consider the more frequent failure types : transient failures. We aim efficient and reliable schedules. The complexity of many variants of this problem is proved. Two heuristics are proposed and compared using using simulations. Even if transient failures are the most common failures in classical grids, some particular type of platform are more concerned by other type of problems. Desktop grids are especially unstable. In this context, we want to execute iterative applications. All tasks are executed, then a synchronization occurs, and so on. Two variants of this problem are considered : applicationsof independent tasks, and applications where all tasks need to be executed at same speed. In both cases, the problem is first theoretically studied, then heuristics are proposed and compared using simulations.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Il presente lavoro si è proposto di indagare il concetto di razionalità limitata nel contesto delle scelte mediche. Sono stati reclutati 80 adulti, senza una storia clinica particolare a cui è stato dapprima somministrato un test virtuale che richiedeva di prendere delle decisioni su alcuni trattamenti e, successivamente, è stata somministrata una intervista semi-strutturata per approfondire il tema della scelta. I principali risultati: in primis, le persone adottano l’uso di euristiche veloci e frugali. In particolare, le persone adottano l’euristica del “Prendi il meglio” considerando, per ogni scelta, un numero limitato di caratteristiche. In secondo luogo, l'uso di euristiche è legato a una razionalità ecologica che adatta le strategie decisionali alla struttura delle informazioni disponibili del contesto ambientale. In questo contesto, se il consiglio del o le informazioni rispetto ai rischi/effetti indesiderati sono disponibili allora essi saranno sempre valutati perché sono caratteristiche fondamentali del processo di scelta. Il consiglio del medico è espressione della fiducia tra medico e paziente. La fiducia è rappresentata da segnali semplici e onesti che il medico è capace di trasmettere e questi segnali formano un canale di comunicazione tra le persone. Infine un altro risultato riguarda la comprensione del rischio associato al consumo di un farmaco che è risultato di difficile comprensione e rappresentazione. / This research aimed at applying the concept of bounded rationality in common medical choices in order to analyse the process by which laypersons make decisions in the field of health. Eighty adults, without a particular disease history were recruited and they were asked to manage both some virtual situations of medical choices and to discuss face to face about their past experiences in medical choices.Three major findings emerged. Firstly, people often use fast and frugal heuristics. In particular, people adopt the rule of the ‘take the best” considering, for each choice, a very limited number of elements to make their decisions. Secondly, the use of heuristics is related with the principle of ecological rationality in which strategies are chosen in connection with the available information of the environmental context. In this context, if “doctor’s advice” as well as “side effects information” are available, they will be always considered because they represent fundamental features of the decision making process. Doctor’s advice is expression of the trust between patient-doctor relationship. Trust is represented by simple and honest signals that the doctor communicates and these signals form an unconscious channel of communication between people. Thirdly, we found that risks associated with treatments are not easy to be conceived by laypersons. It was that people have not in mind a clear definition of the risk implied by medicines and treatment and they show, in average, a scarce interest in risk comprehension.

Several analytical techniques including use case diagrams, process flow diagrams (PFDs), hierarchical task analysis (HTA), failure mode and effects analysis (FMEA), systematic human error reduction and prediction approach (SHERPA), hazard analysis and critical control point (HACCP), heuristics, the Safe Living Guide and the Resident Assessment Instrument – Home Care (RAI-HC) are applied to data obtained from two pilot home visits to determine whether common failure modes, causes, effects and recommendations are yielded by the techniques. The time required to apply each analytical technique to processes uncovered from the pilot data was measured and outputs of the techniques were reviewed for commonality. Of the tools considered, SHERPA was found to return the most failure modes, effects and recommendations, while FMEA was the only human factors tool to yield causes. Additionally, FMEA and SHERPA provided a means of ranking potential failure modes based on severity and probability.

Several analytical techniques including use case diagrams, process flow diagrams (PFDs), hierarchical task analysis (HTA), failure mode and effects analysis (FMEA), systematic human error reduction and prediction approach (SHERPA), hazard analysis and critical control point (HACCP), heuristics, the Safe Living Guide and the Resident Assessment Instrument – Home Care (RAI-HC) are applied to data obtained from two pilot home visits to determine whether common failure modes, causes, effects and recommendations are yielded by the techniques. The time required to apply each analytical technique to processes uncovered from the pilot data was measured and outputs of the techniques were reviewed for commonality. Of the tools considered, SHERPA was found to return the most failure modes, effects and recommendations, while FMEA was the only human factors tool to yield causes. Additionally, FMEA and SHERPA provided a means of ranking potential failure modes based on severity and probability.

This study focuses on two types of routing problems based on standard Traveling Salesman Problem, which are TSP with pickup and delivery (TSPPD) and TSP with backhauls (TSPB). In both of these problems, there are two types of customers, i.e. &ldquo / delivery customers&rdquo / demanding goods from depot and &ldquo / pickup customers&rdquo / sending goods to depot. The objective is to minimize the cost of the tour that visits every customer once without violating the side constraints. In TSPB, delivery customers should precede the pickup customers, whereas the vehicle capacity should not be exceeded in TSPPD. The aim of the study is to propose good Evolutionary Algorithms (EA) for these two problems and also analyze the adaptability of an EA, originally designed for the standard TSP, to the problems with side constraints. This effort includes commenting on the importance of feasibility of the solutions in the population with respect to these side constraints. Having this in mind, different EA strategies involving feasible or infeasible solutions are designed. These strategies are compared by quantitative experiments realized over a set of problem instances and the results are given.