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

Nos tempos atuais, cada vez mais as organizações têm investido em equipamentos e infra-estrutura de educação a distância (EAD). Grande parte dos estudos até hoje realizados dizem respeito a aspectos pedagógicos relacionados a esse tipo de sistema produtivo. Contudo, há poucos estudos dedicados a sua gestão. Esta dissertação busca, por meio de uma pesquisa à literatura pertinente, seguida de uma pesquisa de campo, sistematizar o conhecimento sobre a gestão de um sistema de operações de EAD, buscando formas para otimizar sua disponibilidade operacional. Ao longo do trabalho, a disponibilidade é tratada com um indicador de resultado de duas diferentes funções da organização: função gestão de contratos e função manutenção. A primeira diz respeito ao acordo de nível de serviço (SLA) firmado entre a organização foco deste estudo e um fornecedor de serviços de telecomunicações. A segunda função compreende a forma como são adotadas abordagens ou políticas de manutenção para os equipamentos utilizados para a execução desse tipo de serviço. Assim, descreve-se o contexto em que se inserem a disponibilidade e as duas funções a ela relacionadas e buscam-se formas para coordenar essas funções com o objetivo de otimizar a disponibilidade operacional do sistema produtivo. Algumas proposições foram estruturadas e verificadas numa organização, através da metodologia científica pesquisa-ação. Um instrumento referencial foi elaborado para amparar a pesquisa de campo visando facilitar a verificação das proposições propostas, além de colaborar para melhor atingir os objetivos propostos. A conclusão da pesquisa revela que as proposições de estudo não se confirmaram de forma plena, apontando para um sensível distanciamento entre teoria e pratica organizacional, deixando, assim, espaço aberto para novos estudos. / In present days, organizations are investing increasingly in equipment and infrastructure for distance education (DE). Great part of the studies carried out until today focus on the pedagogical aspects related to this type of productive system. However, there are few studies dedicated to its management. It is the goal of this study, through research in specific literature followed by a field research, to systemize the knowledge on management of an operational system for DE, searching for ways to optimize its operational availability. Throughout the work, the availability is considered a result indicator for two different functions of the organization: contract management function and maintenance function. The former one says respect to the service level agreement (SLA) firmed between the organization, focus of this study, and a supplier of telecommunications services. The latter is concerned with the ways that maintenance approaches and politics for the equipment involved in the execution of this type of service are adopted. Thus, the context in which the availability and both related functions are enclosed has been described and ways to co-ordinate these functions with the goal of optimizing the productive system operational availability is searched. The framework of some proposals was developed and verified in an organization through the scientific methodology ?Action Research?. A reference instrument was elaborated to support the field research aiming to ease the verification of the proposals that have been made, besides helping to achieve the proposed goal. The research conclusion discloses that the study proposals weren?t fully confirmed, leading to a considerable withdraw between organizational theory and practice, leaving, thus, an open space for new studies.

O objetivo deste estudo é realizar a avaliação da estrutura de três instituições públicas com relação às propostas de inovação organizacional por meio das mudanças em seus processos de trabalho. Este estudo abrange os contratos terceirizados realizados por meio de processo licitatório com a utilização de Acordo de Nível de Serviço (ANS), que possui critérios objetivos de mensuração dos resultados contratados. Isso permite adequar o pagamento das faturas dos contratos de acordo com a quantidade e qualidade dos serviços prestados, constituindo o processo inovativo a ser estudado neste trabalho. Para isso, foram realizadas entrevistas com servidores das áreas que atuam desde o planejamento até o acompanhamento e execução dos contratos terceirizados continuados de forma a verificar a percepção com relação à inovação em sua instituição, cultura organizacional e apoio da alta administração. Dentre os contratos terceirizados, optou-se por avaliar os serviços prestados referente ao contrato específico de limpeza. Identificou-se que a instituição A possui a contratação por posto de trabalho sem que haja uma avaliação especifica para a qualidade dos serviços prestados vinculado ao pagamento da fatura, mesmo com total abertura para projetos inovadores. Esse modelo de contratação, atualmente, supre com as demandas da instituição. Já as instituições B e C possuem a contratação com utilização de ANS. Apesar de possuírem obstáculos com relação à adoção de inovação, observou-se que essas duas instituições possuem um modelo diferenciado de gerir seus contratos com inovação em seu processo. Verificou-se que as três instituições conseguem atingir os objetivos esperados para os contratos apresentados tais como a qualidade na entrega dos serviços prestados e o correto pagamento da fatura com relação ao serviço executado. Apesar disso, como existe a possibilidade de contratar futuramente uma empresa que não atinja a qualidade esperada ou que não tenha a competência para tal, é importante avaliar a implantação do ANS nos contratos futuros. / This paper aims to evaluate the structure of three public institutions’ regarding the proposals for organisational innovation through changes in their work processes. This study includes third-party vendors contracts through a bidding process with the use of Service Level Agreements (ANS in Brazil), which has objectives evaluates contracts. This allows adjusting the payment of the contracts according to the quantity and quality of the services provided, constituting the innovative process to be studied in this work. For that, interviews with workers in areas from planning to execution of continued third-party contracts were conducted to check the perception of innovation in their institution, organisational culture and managers’ support. Among the outsourced contracts, we opted to evaluate the services referring to the specific cleaning contract. The institution A has the type of contract by workstation without specifically check the quality of services provided which were paid, even with possibility for innovative projects. This contracting model currently meets the demands of the institution A. Institutions B and C follows Service Level Agreements. Despite they usually reach an impasse on innovation process, it was noted that these two institutions follows a particular model to manage their contracts with innovation. It was verified that the three institutions achieves the goals expected for contracts provided, which consists in the quality of services provided, followed by the due payment. The evaluate of the employment of Service Level Agreements is important, because there are no guarantees that a future contract will reach the expected quality.

La congestión vehicular se ha convertido en una constante en la vida citadina y Lima no es la excepción. Sin embargo, existen acciones que pueden ser implementadas para minimizar el tiempo que se pierde al circular por vías de alto tránsito, especialmente durante horas pico, como es el caso de la red constituida por las avenidas Faustino Sánchez Carrión. y La Marina, desde la Av. Gregorio Escobedo hasta la Av. Antonio José de Sucre. En ese contexto, el propósito del presente trabajo es brindar una alternativa de gestión de la oferta vial que contribuya con la optimización de los indicadores de medición del tráfico; entre ellos, el grado de saturación, el nivel de servicio de las intersecciones que forman parte de la investigación y las demoras por tiempo de espera. Para ello, se hace uso de Synchro 8, un software de simulación que sirve de soporte para la generación del modelo de solución, efectuado a nivel mesoscópico. Synchro es compatible con el Highway Capacity Manual - HCM 2000 y 2010; pero además, cuenta con una serie de herramientas que le permiten incorporar su propia técnica de análisis. En el caso de este proyecto, la evaluación del tráfico se desarrolla mediante la Metodología del Automóvil de HCM 2010; sin considerar el análisis de peatones ni ciclistas. Los resultados obtenidos demuestran que es posible optimizar el tráfico vehicular a través del uso correcto de simuladores de tránsito y no solo con intervenciones geométricas de gran escala o excesiva inversión en nueva infraestructura. / Traffic congestion has become a constant in city life, and Lima is not the exception. However, there are actions that can be implemented to minimize the time lost when traveling on high-traffic routes, especially during rush hours, such as the case of the road network formed by the Faustino Sánchez Carrión and La Marina avenues, from Gregorio Escobedo Ave. to Antonio José de Sucre Ave. In that context, the purpose of this project is to provide an alternative of road offer management which contributed to improving traffic measurement indicators; among them, saturation degree, intersections level of service that are part of the research, and delays due to waiting time. In doing so, Synchro 8 is used. This simulation software functions as a support for the solution model generation, which is performed at the mesoscopic level. Synchro is compatible with the Highway Capacity Manual - HCM 2000 and 2010; but also, it has a set of tools that allow it to incorporate its own analysis technique. In the case of this project, traffic evaluation is developed on the basis of vehicular operation system by means of the HCM 2010 Automobile Methodology; that is, the pedestrians and cyclists analysis are not taken into consideration. The results obtained show that it is possible to optimize vehicular traffic through the correct use of traffic simulators and not only through large-scale geometric interventions, or with excessive investment in new infrastructure. / Tesis

ABSTRACT A GENETIC ALGORITHM FOR p-HUB CENTER PROBLEM WITH STOCHASTIC SERVICE LEVEL CONSTRAINTS Eraslan Demirci, S&uuml / kran M.Sc., Department of Industrial Engineering Supervisor: Asst. Prof. Dr. Sedef Meral December 2010, 170 pages The emphasis on minimizing the costs and travel times in a network of origins and destinations has led the researchers to widely study the hub location problems in the area of location theory in which locating the hub facilities and designing the hub networks are the issues. The p-hub center problem considering these issues is the subject of this study. p-hub center problem with stochastic service level constraints and a limitation on the travel times between the nodes and hubs is addressed, which is an uncapacitated, single allocation problem with a complete hub network. Both a mathematical model and a genetic algorithm are proposed for the problem. We discuss the general framework of the genetic algorithm as well as the problem-specific components of algorithm. The computational studies of the proposed algorithm are realized on a number of problem instances from Civil Aeronautics Board (CAB) data set and Turkish network data set. The computational results indicate that the proposed genetic algorithm gives satisfactory results when compared with the optimum solutions and solutions obtained with other heuristic methods.

<p>With Cloud Computing becoming a popular term on the Information Technology (IT) market, security and accountability has become important issues to highlight. In our research we review these concepts by focusing on security risks with Cloud Computing and the associated services; Software, Platform and Infrastructure (SPI) and connecting them with a social study of trust.</p><p>The method that was conducted during our research was reviewing secondary literature, interviewing different experts regarding Cloud Computing and relating standards already established by ENISA, NIST, and CSA to the interviews.</p><p>The result of this study shows connections between the specific SPIs, both how they compare, but also how they differ. In the end we were also able to rank the top security risks from interviews with experts and see which SPI could be the most insecure one and  what countermeasures could be applied.</p><p>This was further related to trust and Service Level Agreement (SLA) in Cloud Computing to show how the security risks we discuss are related to these two specific areas. By highlighting this we wanted to present useable information for both clients and providers in how to create a better Cloud Computing environment.</p>

M. Tech. Business Administration (MBA) / Information technology (IT) services have become strategic to business. Complex IT environments are usually managed according to a service management framework of which the Information Technology Infrastructure Library (ITIL) is the de facto standard. Due to a lack of studies on service quality and the Information Technology Infrastructure Library in South Africa, this research was focused on how service quality is perceived by the business after the adoption of the Information Technology Infrastructure Library. The purposes of this research were: to identify which dimensions of service quality contributed most significantly to the service quality gap; to determine what the perceptions of service quality were after the implementation of the Information Technology Infrastructure Library; and how the opinions of service quality differ between the Information technology division and the business.

Αντικείμενο της παρούσας Διατριβής είναι η μελέτη της απόδοσης και η εισαγωγή νέων χαρακτηριστικών σε μοντέλα για την παροχή υπηρεσιών με εγγυήσεις ποιότητας στα σύγχρονα IP δίκτυα καθώς και η εισαγωγή των απαραίτητων επιχειρησιακών λειτουργιών για την εφαρμογή των μοντέλων αυτών, με στόχο τη βελτίωση της απόδοσης. Ακολουθώντας μια καταγραφή και αξιολόγηση των μηχανισμών και αρχιτεκτονικών που εισάγουν τη διαφοροποίηση εξυπηρέτησης στα IP δίκτυα, η μελέτη που παρουσιάζεται εδώ ακολουθεί σε όλα της τα στάδια τις αρχές της αρχιτεκτονικής DiffServ, η οποία επιτρέπει την παροχή ενός συγκεκριμένου εύρους υπηρεσιών με εγγυήσεις ποιότητας σε συναθροίσεις ροών και περιορίζει την πολυπλοκότητα στα όρια του δικτύου. Η απόδοση και η αποτελεσματικότητα των μηχανισμών και λειτουργιών διαφοροποίησης εξυπηρέτησης με βάση την αρχιτεκτονική DiffServ αξιολογούνται με βάση την εξασφάλιση εγγυημένης χωρητικότητας, φραγμένης από-άκρο-σε-άκρο καθυστέρησης, ελαχιστοποιημένων απωλειών πακέτων και φραγμένου jitter. Ωστόσο, σε κάθε μοντέλο υπηρεσίας για την παροχή QoS, τονίζεται η σημασία της εξασφάλισης των καλύτερων δυνατών εγγυήσεων ποιότητας με την ελάχιστη δυνατή πολυπλοκότητα. Τα διαφορετικά μοντέλα υπηρεσιών θέτουν συγκεκριμένους στόχους λαμβάνοντας υπόψη τις ανάγκες των εφαρμογών στις οποίες απευθύνονται. Οι δύο επικρατέστερες κατηγορίες υπηρεσιών στα πλαίσια της αρχιτεκτονικής DiffServ είναι η κατηγορία των υπηρεσιών μέγιστης προτεραιότητας και η κατηγορία των υπηρεσιών εγγυημένης χωρητικότητας σε συνθήκες συμφόρησης. Στην πρώτη κατηγορία, προτείνεται το μοντέλο υπηρεσίας Gold, το οποίο ακολουθεί τις αρχές τις αρχιτεκτονικής DiffServ για να παρέχει βέλτιστη ποιότητα εξυπηρέτησης σε συναθροίσεις IP ροών, ενώ ταυτόχρονα μπορεί να εφαρμοστεί πρακτικά σε δίκτυα παραγωγής. Στη δεύτερη κατηγορία, προτείνεται το μοντέλο υπηρεσίας Relative για την παροχή υπηρεσιών εγγυημένης χωρητικότητας σε συνθήκες συμφόρησης, με βασικά χαρακτηριστικά την μείωση της υπολογιστικής πολυπλοκότητας και την βελτίωση της δικαιοσύνης μεταξύ των εξυπηρετούμενων TCP ροών. Η υπηρεσία Gold διατηρεί την αρχή της επεκτασιμότητας και παρέχει αυστηρές εγγυήσεις ποιότητας αλλά ταυτόχρονα επιτρέπει την εφαρμογή μηχανισμού ελέγχου αποδοχής νέων αιτημάτων χωρίς διακοπή της λειτουργίας του δικτύου. Eισάγει επίσης ένα νέο χαρακτηριστικό σε σχέση με τα υπάρχοντα σχήματα: την διαφοροποίηση ως προς την εγγυημένη μέγιστη καθυστέρηση που παρέχεται στις ροές. Υλοποιείται με τη χρονοδρομολόγηση LA-EDF, που εισάγει την έννοια της διαφοροποιημένης εξυπηρέτησης εντός της ίδιας κλάσης υπηρεσίας και λειτουργεί ως υποστηρικτικός μηχανισμός του ελέγχου αποδοχής κλήσεων, τον αλγόριθμο DBAC για την αποδοχή κλήσεων χωρίς επέμβαση στη λειτουργία του δικτύου και την δρομολόγηση εξισορρόπησης φόρτου για την καλύτερη αξιοποίηση των διαθέσιμων πόρων χωρίς να παραβιάζονται οι εγγυήσεις ποιότητας. Η υπηρεσία Relative επιτυγχάνει προσαρμοστικότητα σε συνθήκες μεταβαλλόμενου φόρτου, δίκαιη διαφοροποίηση, υψηλή απόδοση, αύξηση της χρησιμοποίησης των διαθέσιμων πόρων ενώ αντιμετωπίζει πολλές από τις αδυναμίες που παρουσιάζουν αντίστοιχα μοντέλα. Υλοποιείται με τον μηχανισμό μαρκαρίσματος TWAM ο οποίος εφαρμόζεται στο σημείο εισόδου των ροών στο δίκτυο και αντιμετωπίζει τα θέματα της μη δίκαιης μεταχείρισης TCP ροών με τη μικρότερη δυνατή υπολογιστική επιβάρυνση σε σχέση με υπάρχοντες μηχανισμούς μαρκαρίσματος και τον μηχανισμό DWRED για την ενεργητική διαχείριση του αποθηκευτικού χώρου των ουρών, ο οποίος λειτουργεί με βάση το μαρκάρισμα της κίνησης που επιφέρει ο TWAM και προσαρμόζεται στις μεταβαλλόμενες συνθήκες λειτουργίας. Μεταξύ των καθοριστικών παραγόντων για την ευρεία υιοθέτηση υπηρεσιών βασισμένων στην αρχιτεκτονική DiffServ στα σύγχρονα δίκτυα παραγωγής, αναδεικνύονται η εισαγωγή ευέλικτων επιχειρηματικών μοντέλων για την υλοποίηση των υπηρεσιών αυτών στο εσωτερικό ενός δικτύου καθώς και χρέωσης των παρεχόμενων υπηρεσιών. Ο ορισμός Συμβολαίων Εξασφάλισης Επιπέδου Υπηρεσιών (ΣΕΕΥ) για δίκτυα που υποστηρίζουν την παροχή QoS υπηρεσιών με βάση την αρχιτεκτονική DiffServ έχει ως στόχο την εξασφάλιση της συμβατότητας των παρεχόμενων από διαφορετικά διασυνδεδεμένα δίκτυα υπηρεσιών προκειμένου για την από-άκρο-σε-άκρο εξασφάλιση εγγυήσεων ποιότητας. Προτείνεται ένα πρότυπο για την υλοποίηση διμερών ΣΕΕΥ σε IP δίκτυα που παρέχουν υπηρεσίες μέγιστης προτεραιότητας καθώς και μια μεθοδολογία για την υλοποίηση από-άκρο-σε-άκρο Συμβολαίων πάνω από διασυνδεδεμένα δίκτυα. Σε ένα IP δίκτυο, η εισαγωγή ενός αριθμού κλάσεων υπηρεσιών που διαφοροποιούνται στις παρεχόμενες ποιοτικές εγγυήσεις απαιτεί την εισαγωγή διαφοροποιημένων μοντέλων χρέωσης που επιπρόσθετα οδηγούν τους χρήστες στην επιλογή της κατάλληλης κλάσης υπηρεσίας η οποία μεγιστοποιεί την αντιληπτή χρησιμότητα. Προκειμένου για τη χρέωση υπηρεσιών με βάση την αρχιτεκτονική DiffServ, τα προφίλ κίνησης των χρηστών και οι διαφορές στην αντιληπτή ποιότητα αντιπροσωπεύουν τη χρησιμότητα που αντιλαμβάνεται ο χρήστης. Προτείνεται ένα μοντέλο χρέωσης όπου το προφίλ της κίνησης αποτελεί το αντικείμενο διαπραγμάτευσης του χρήστη με τον πάροχο, αφού ο χρήστης συνυπολογίσει τις εγγυήσεις ποιότητας εξυπηρέτησης που ανακοινώνονται από τον τελευταίο προκαταβολικά. Η καινοτομία του προτεινόμενου μοντέλου συνίσταται στις εξωτερικές συνθήκες (externalities) που υπεισέρχονται στα υφιστάμενα κόστη και προκαλούνται από τη φύση των υπηρεσιών που υλοποιούνται με βάση το μοντέλο DiffServ, καθώς επίσης και στον καθορισμό των πραγματικών τιμών με βάση τις οποίες χρεώνονται οι χρήστες. / The goal of this Dissertation is to study the performance of existing tools and the introduction of new features to quality of service provisioning models in IP networks as well as the introduction of the business models required for applying these models in an operational environment in ways that the performance is improved. Following the evaluation of mechanisms and architectures for differentiation of service in IP networks, the principles of the DiffServ framework have been adopted. The DiffServ framework specifies the provision of a set of services with qualitative guarantees to traffic aggregates, while keeping complexity at the network edges. The performance and effectiveness of service differentiation mechanisms according to the principles of the DiffServ framework are evaluated according to the following metrics: guaranteed capacity, bounded end-to-end delay, minimization of packet losses and jitter. However, in any QoS model, it is important to ensure the best quality possible by keeping complexity low. Each QoS model is designed to meet the needs of a different traffic type. The two prevailing service models within the DiffServ framework are the maximum priority, maximum quality model and the guaranteed capacity under congestion model. The proposed Gold service falls within the first category above, offering advanced quality to IP traffic aggregates with a set of principles that can easily be applied to operational networks. The proposed Relative service model provides guaranteed capacity under congestion by reducing the complexity and improving fairness among TCP flows. The Gold service preserves scalability and provides strict quality guarantees, incorporating a call admission control mechanism that operates without interfering with the network operations. It introduces a novel feature: differentiation of the guarantees on end-to-end delay provided to traffic flow. It is implemented using LA-EDF scheduling that introduces service differentiation within the same class and supports the call admission control functions, the DBAC algorithm for admission control and flow routing with load balancing for optimizing the use of available resources without compromising in terms of the guaranteed quality. The Relative service achieves high adaptability in transient load conditions, fair differentiation, high quality, increase in the utilization of available resources without demonstrating the same weaknesses as equivalent service models. It is implemented using the TWAM marking mechanism, which is applied at the network ingress and ensures fairness with less overhead than similar mechanisms, and DWRED, the active queue management mechanism that depends upon the TWAM marking and adapts to the varying load levels. The introduction of effective business and pricing models is crucial for the adoption of qualitative service models based on the DiffServ framework in a production network. The definition of Service Level Agreements (SLAs) for networks that provide QoS according to the principles of the DiffServ framework aims at introducing compatibility among the services provided for the provisioning of end-to-end quality guarantees. A template for the implementation for bilateral SLAs between networks that support the maximum priority, maximum quality service model is proposed, together with a methodology for implementing, based on the bilateral SLA, an end-to-end SLA over multiple domains. In an IP network, the introduction of a set of services classes with differing quality guarantees necessitates the application of differentiated pricing models that lead the users to the selection of the appropriate service class in order to maximize their perceived utility. Based on the principles of the DiffServ framework, the utility for each user is determined by the profile of his traffic and the quality of service he perceives. The proposed pricing model appoints the traffic profile as the parameter for negotiation between the user and the provider, after the user assesses the quality guarantees announced by the provider prior to the service provisioning. The innovation here lies in the introduction of externalities to the costs induced as well as the announcement of the actual prices upon which the user will eventually be charged. The externalities are imposed by the nature of the service models implemented according to the DiffServ framework.

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

The emergence of new architectures like the cloud open new challenges for data management. It is no longer pertinent to reason with respect a to set of computing, storage and memory resources, instead it is necessary to conceive algorithms and processes considering an unlimited set of resources usable via a "pay as U go model", energy consumption or services reputation and provenance models. Instead of designing processes and algorithms considering as threshold the resources availability, the cloud imposes to take into consideration the economic cost of the processes vs. resources use, results presentation through access subscription, and the parallel exploitation of available resources. Our research contributes to the construction of service based data management systems. The objective is to design data management services guided by SLA contracts. We proposed methodologies, algorithms and tools for querying, deploying and executing service coordinations for programming data management functions. These functions, must respect QoS properties (security, reliability, fault tolerance, dynamic evolution and adaptability) and behaviour properties (e.g., transactional execution) adapted to application requirements. Our work proposes models and mechanisms for adding these properties to new service based data management functions.