Thanks to the wide range of features offered by the World Wide Web (WWW), many web applications have been published and developed through different libraries and programming languages. Adapting to new changes, the Web quickly evolved into a complex ecosystem, introducing many security problems to its users. To solve these problems, instead of re-designing the Web, the vendors added the security patches (protocols, mechanisms)to the Web platform to provide a more convenient and more secure environment for web users. However, not only did these patches not completely resolve the security problems, but their implementations also introduced other security risks unbeknownst to website operators and users. In this thesis, I propose a novel research on two different security patches to understand and analyze their deployment in real-world scenarios and discover the unseen, neglected factors and the elements involved in exploiting their use: one security protocol, OAuth, and one security mechanism, CORS. As this thesis is based on offensive approaches, I develop automated methodologies, including novel strategies for analyzing and measuring the security qualities of the OAuth protocol and CORS mechanism in real-world scenarios.

This thesis investigates strategic alliances in the aviation industry, focusing on resource sharing, using Scandinavian Airlines (SAS) within Star Alliance and SkyTeam as case studies. It examines the operational and competitive benefits of these collaborations through qualitative research, including interviews with executives and experts. The study highlights alliance dynamics like antitrust immunity, code sharing, and the resource-based view. Findings show alliances improve operational efficiency, competitive positioning, and customer service. It also considers the impact of new technologies and global events on alliances, which pool tangible (technology, infrastructure) and intangible assets (brand reputation, identity), fostering deeper integration. This research enhances understanding of strategic drivers in airline alliances and the complexities of resource sharing in the global aviation sector.

The computing needs and the input and result datasets of modern scientific and enterprise applications are growing exponentially. To support such applications, High-Performance Computing (HPC) systems need to employ thousands of cores and innovative data management. At the same time, an emerging trend in designing HPC systems is to leverage specialized asymmetric multicores, such as IBM Cell and AMD Fusion APUs, and commodity computational accelerators, such as programmable GPUs, which exhibit excellent price to performance ratio as well as the much needed high energy efficiency. While such accelerators have been studied in detail as stand-alone computational engines, integrating the accelerators into large-scale distributed systems with heterogeneous computing resources for data-intensive computing presents unique challenges and trade-offs. Traditional programming and resource management techniques cannot be directly applied to many-core accelerators in heterogeneous distributed settings, given the complex and custom instruction sets architectures, memory hierarchies and I/O characteristics of different accelerators. In this dissertation, we explore the design space of using commodity accelerators, specifically IBM Cell and programmable GPUs, in distributed settings for data-intensive computing and propose an adaptive framework for programming and managing heterogeneous clusters. The proposed framework provides a MapReduce-based extended programming model for heterogeneous clusters, which distributes tasks between asymmetric compute nodes by considering workload characteristics and capabilities of individual compute nodes. The framework provides efficient data prefetching techniques that leverage general-purpose cores to stage the input data in the private memories of the specialized cores. We also explore the use of an advanced layered-architecture based software engineering approach and provide mixin-layers based reusable software components to enable easy and quick deployment of heterogeneous clusters. The framework also provides multiple resource management and scheduling policies under different constraints, e.g., energy-aware and QoS-aware, to support executing concurrent applications on multi-tenant heterogeneous clusters. When applied to representative applications and benchmarks, our framework yields significantly improved performance in terms of programming efficiency and optimal resource management as compared to conventional, hand-tuned, approaches to program and manage accelerator-based heterogeneous clusters. / Ph. D.

The purpose with this report is to speculate how our neighborhoods could look like in the future, looking at modern collective living due to the housing crisis is Sweden today. This paper will look att different forms of collective housing, to challenge the conventional way of living. Connecting sustainability to the act of sharing space and resources, in creating a collaborative lifestyle. The research methods used in this speculative project looks at three case studies of collective housing to analyse and define different levels of sharing. During the design process one intervention was executed to challenging the norm of ownership, questioning what the act of sharing demands. The goal of this project is to change assumptions of collective living by rethinking space. To create an interlaced community, with hopes of becoming more resilient. The research and its findings worked along- side the report and developed into a zine. The zine was made with key insights from the study, as a tool to communicate the design proposal and can easily be distributed to the Swedish population.

Resource sharing is a common collaborative strategy used in practice. It has the potential to create synergistic value and leads to higher system efficiency. However, realizing this synergistic value can be challenging given the prevalence of decentralization in practice, where individual operators manage resources based on their own benefits. Hence, optimizing a decentralized system requires understanding not only the optimal operational strategy in terms of the overall system efficiency, but also the implementation of the strategy through proper management of individual incentives. However, traditional network optimization approaches typically assume a centralized perspective. The classic game theory framework, on the other hand, addresses incentive issues of decentralized decision makers, but mainly takes a high-level, economic perspective that does not fully capture the operational complexity involved in optimizing systems with resource sharing. The purpose of this thesis is to bridge this gap between practice and theory by studying the design of tools to manage and optimize the operations in decentralized systems with resource sharing using approaches that combine optimization and game theory. In particular, we focus on decentralized network systems and analyze two research streams in two application domains: (i) implementation of environmental legislation, and (ii) managing collaborative transportation systems. These applications are characterized by their decentralized multi-stakeholder nature where the conflicts and tension between the heterogeneous individual perspectives make system management very challenging. The main methodology used in this thesis is to adopt game theory models where individual decisions are endogenized as the solutions to network optimization problems that reflect their incentives. Such an approach allows us to capture the connection between the operational features of the system (e.g., capacity configuration, network structure, synergy level from resource sharing) and the individual incentives thus the effectiveness of the management tools, which is a main research contribution of this thesis. In the first research stream, we consider designing effective, efficient and practical implementation of electronic waste take-back legislation based on the widely-adopted Extended Producer Responsibility (EPR) concept that mandates the financial responsibility of post-use treatment of their products. Typical implementations of EPR are collective, and allocate the resulting operating cost to involved producers. In this thesis, we demonstrate the complexity of collective EPR implementation due to the tension among different stakeholder perspectives, based on a case analysis of the Washington implementation. We then perform analytical studies of the two prominent challenges identified in current implementations: (i) developing cost allocation mechanisms that induce the voluntary participation of all producers in a collective system, thus promoting implementation efficiency; and (ii) designing collective EPR so as to encourage environmentally-friendly product design, thus promoting implementation effectiveness. Specifically, we prescribe new cost allocation methods to address the first challenge, and demonstrate the practicality and economic impact of the results using implementation data from the state of Washington. We then analyze the tensions between design incentives, efficiency and the effectiveness of the cost allocation to induce voluntary participation under collective EPR implementation. We show there exists a tradeoff among the three dimensions, driven by the network effects inherent in a collective system. The main contribution of this research stream is to demonstrate how the implementation outcomes of an environmental policy is influenced by the way that the policy ``filters' through operational-level factors, and to propose novel and implementation mechanisms to achieve efficient and effective EPR implementation. Hence, our study has the potential to provide guidance for practice and influence policy-making. In the second research stream, motivated by the practice of transportation alliances, we focus on a decentralized network setting where the individual entities make independent decisions regarding the routing of their own demand and the management of their own capacity, driven by their own benefits. We study the use of market-based exchange mechanisms to motivate and regulate capacity sharing so as to achieve the optimal overall routing efficiency in a general multicommodity network. We focus on the design of capacity pricing strategies in the presence of several practical operational complexities, including multiple ownership of the same capacity, uncertainty in network specifications, and information asymmetry between the central coordinator and individual operators. Our study in this research stream produces two sets of results. First, we demonstrate the impact of the underlying network structure on the effectiveness of using market-based exchange mechanisms to coordinate resource sharing and to allocate the resulting synergistic benefit, and characterize the network properties that matter. Second, we propose efficient and effective pricing policies and other mechanism design strategies to address different operational complexities. Specifically, we develop duality-based pricing algorithms, and evaluate different pricing strategies such as commodity-based price discrimination, which is shown to have an advantage in coordinating networks under uncertainty.

A maioria dos rios do semiÃrido apresentam regimes irregulares e intermitentes, com um sà perÃodo anual de escoamento na chegada das precipitaÃÃes pluviomÃtricas que caracterizam o perÃodo chuvoso. Nesses rios, as perturbaÃÃes hidrolÃgicas naturais exercem forte influÃncia na organizaÃÃo do sistema, sendo as interaÃÃes alimentares complexas e modificadas pela sazonalidade e pela produtividade do sistema. A dieta de peixes pode variar de acordo com a disponibilidade de recursos alimentares de origem autÃctone ou alÃctone, bem como em resposta à variaÃÃo sazonal. A hipÃtese do presente estudo à de que em um rio do semiÃrido as espÃcies de peixes herbÃvoras/ onÃvoras apresentam partilha de recursos trÃficos. O objetivo foi determinar a partilha de recursos trÃficos a partir da dieta de quatro espÃcies de peixes no rio Curu. As coletas foram realizadas em um trecho do rio Curu (Pentecoste, CearÃ), no perÃodo chuvoso de 2010. Foi analisado o conteÃdo estomacal de 197 indivÃduos das seguintes espÃcies: Astyanax bimaculatus (27), Astyanax fasciatus (79), Poecilia vivipara (90) e Hypostomus jaguribensis (1), pelo mÃtodo volumÃtrico e frequÃncia de ocorrÃncia, para o cÃlculo do Ãndice alimentar (IAi). Com os dados morfomÃtricos foi obtido o Quociente Intestinal (QI). A amplitude de nicho foi estimada atravÃs do Ãndice de Levins e a sobreposiÃÃo trÃfica atravÃs do Ãndice de Pianka. PadrÃes de sobreposiÃÃo de nicho trÃfico foram calculados e estatisticamente testados contra um modelo nulo, atravÃs dos algoritmos de randomizaÃÃo RA3 e RA4. A dieta de A. bimaculatus foi constituÃda por 13 itens, e a de A. fasciatus constituÃda por 15, com preferÃncia alimentar pela alga filamentosa Spirogyra em ambas as espÃcies, sendo a importÃncia alimentar de 89,34% para A. bimaculatus e 96,86% A. fasciatus. A dieta de P. vivipara foi constituÃda por 60 itens, com maior importÃncia para as algas diatomÃceas (28,82%), clorofÃceas (23,17%) e cianofÃceas (5,2%), tendo as clorofÃceas Spirogyra e Closterium, maior importÃncia alimentar com 12,89% e 8,85%, respectivamente e fragmentos de insetos aquÃticos com 39,18%. A dieta de H. jaguribensis esteve constituÃda por 42 itens alimentares, com maior importÃncia para Spirogyra com 23,42%, e Compsopogon com 19%. O grupo diatomÃcea apresentou maior nÃmero de itens na dieta com 21 tÃxons e 16,38% de IAi, seguido pelo item alimentar detrito com 27,72% de importÃncia. De acordo com o quociente intestinal A. bimaculatus e A. fasciatus apresentam intestino caracterÃstico de carnÃvoro/onÃvoro e P. vivipara de herbÃvoro. A anÃlise de variÃncia (ANOVA) para os valores mÃdios do quociente intestinal dos peixes analisados foi significativa com F= 3,50, df = 2, p< 0,05. A largura de nicho foi maior em P. vivipara com 1.32, seguido por A. bimaculatus com 0,78 e A. fasciatus com 0,426. Maior sobreposiÃÃo de nicho ocorreu entre as espÃcies de Astyanax com o valor de 0,98. A anÃlise dos modelos nulos realizados pelos itens totais e os itens agrupados indicou que os valores observados foram sempre maiores do que os esperados para a matriz RA3 e RA4. A variÃncia mÃdia observada tambÃm foi maior do que a simulada. De acordo com a dieta das quatro espÃcies analisadas, destacam a importÃncia de itens de origem autÃctone, principalmente as algas. Os modelos nulos indicam que as espÃcies de peixes herbÃvoras/onÃvoras apresentam partilha de recursos trÃficos, ou seja, a competiÃÃo nÃo à o agente estruturador dessa comunidade. / The semiarid rivers present two patterns: the intermittent and the irregular one, with a single flowing off period per year, during the rainy season. In these rivers, the natural hydrological disturb acts as an important factor driving the organization of the system, in which feeding interactions are complex and modified by seasonality and system productiveness. Fishes often feed on autochthonous or allochthonous resources, with their diets varying according to the with seasonal variation of food availability. The hypothesis of this the present study is that in the semiarid river herbivorous/onivorous fish species present trophic resources partitioning. The major aim of this study the present investigation is was to determine the trophic resources partitioning for four species of fishes at in the Curu River. Field work collections were carried out throughout the rainy season, at the Curu River, in Pentecoste city town, in Cearà state. The stomach content of 197 individuals of the species Astyanax bimaculatus (27), Astyanax fasciatus (79), Poecilia vivipara (90) e Hypostomus jaguribensis (1) was analyzed through the volumetric method in order to obtain for the frequency of each feeding item, so that the Index of Alimentary Importance (IAi) could have been measured. The morphometric data were used to obtain the intestinal quotient (IQ), the niche breadth estimated for the Levinsâ index and the trophic overlap for the Piankaâs index. Patterns of trophic niche overlap were calculated and statistically tested against a null model using the randomization algorithms RA3 and RA4. A. bimaculatus and A. fasciatus fed on 13 and 15 items, respectively. Both species presented feeding preferences for the filamentous algae Spirogyra sp., encompassing 89.34% and 96.86% of their diets, respectively. Poecilia viviparaâs diet comprised 60 items, mainly made up of algae (Bacillariophyta - 28.82%, Chlorophyta - 23.17% and Cyanophyta â 5.2%). Amongst the âgreen algaeâ, Spirogyra sp. (12.89%) and the Closterium sp. (8.85%) were the chief principal items eaten. Aquatic insects (39.18%) made up the second most important item. A total of 42 items compounded the diet of H. jaguribensis, which detritus (27,72%), the algae Spyrogira sp. (23.42%) and Compsopogon sp. (19%) were the foremost most important items. The diatom group comprised the most abundant item, with 21 taxa and 16.38% of IAi. According to the intestinal quotient, A. bimaculatus e A. fasciatus showed a typical carnivorous/omnivorous intestine, whereas P. vivipara showed a herbivorous one. The analysis of variance shows that the intestinal quotient varied among species (F = 3.50; d.f = 2; p < 0.05). The niche breadth was greater for P. vivipara (1.32), followed by A. bimaculatus (0.78) and A. fasciatus (0.426). The higher niche overlap occurred within the Astyanax species (0.98). The null model analysis carried out for the total and clustered grouped items indicated that the observed values were always higher than the expected ones for the RA3 and RA4 matrices. In addition, the mean observed variance was higher than the simulated one. The four studied fish species fed mainly on autochthonous items, chiefly on algae. The null models demonstrated that there is a resource partitioning amongst these herbivorous/omnivorous fish species, where competition seems not to be the structuring agent.

The development of library Consortia in Zimbabwe was necessitated by the need to reduce subscription costs and to widen access to electronic resources as well as implement new technologies among academic libraries. The development of Zimbabwe University Library Consortium (ZULC) and College and Research Library Consortium (CARLC) enabled libraries to cooperate and collaborate in building capacity to support teaching, learning and research through access to quality scholarly information. The trajectory of consortia development in Zimbabwe since 2002 has however been characterised by a focus on the academic sector to the exclusion of other types of libraries. The future development of library consortia in Zimbabwe can be better envisioned when correlated with the country’s national development agenda. While not made explicit, this agenda is underpinned by the idea of access to information. This study investigated how the benefits of the existing library consortia can be harnessed to promote the achievement of Zimbabwe’s national development goals. More specifically, it examined the ways that the development paths of ZULC and CARLC can be transformed to support the country’s national development agenda and programmes. This culminated in a model that will accelerate and guide the future development of its library consortia to facilitate a supporting developmental role. The novel aspect of this study is that it seeks to integrate library consortia into the national development plans of a developing country and to extend their benefits as widely as possible. An extensive literature review of the characteristics, models, and development of consortia in selected countries was complemented by an empirical mixed-method component that generated data through interviews, questionnaires, observation, and the analysis of key documents. A special feature of the study is a detailed analysis of the successes and challenges of library consortia in other countries and in the Southern African region to supplement the empirical data that informs the proposed model. The main finding is that a model with a multi-type structure and a National Coordinating Committee is best to transform the development paths of Zimbabwe’s academic library consortia to support the country’s national development agenda. The model’s key elements are finance, structure, governance, functions, and special features. / Thesis (PhD)--University of Pretoria, 2017. / Information Science / PHD / Unrestricted

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The advent of 5th generation of mobile networks (5G) will introduce some new challenges for the transport network. Different strategies can be employed by the network providers to address these challenges with the aim to achieve an efficient utilization of network resources. The most feasible option to achieve this goal is to introduce intelligence in the transport infrastructure by designing a flexible and programmable transport network. Network function virtualization (NFV) and dynamic resource sharing (DRS) are two possible techniques for realizing a flexible transport network. NFV allows to dynamically push network functions to different locations in the network, while DRS allows for sharing transport resources in a flexible manner. Both of these strategies can be realized by employing a programmable control framework based on software defined networking (SDN), which has implications on both the network data and control planes. However, this thesis specifically focuses on the data plane aspects of NFV and the control plane aspects of DRS. Considering the network caching as a specific example of network function, the data plane aspects of NFV are studied in terms of different architectural options for cache placement in order to see which options are the most efficient in terms of network power consumption and cost. The results presented in this thesis show that placing large-sized caches farther in the network for a large group of users is the most efficient approach. The control plane aspects of DRS are analyzed in terms of which provisioning strategy should be used for sharing a limited amount of transport resources. The analysis is presented for both a single-tenant case (i.e., where the role of service and network provider is played by the same entity), and a multi-tenant case (i.e., where a network provider manages the resources assigned to different service providers in an intelligent way). The results show that DRS performs much better than the conventional static approach (i.e., without sharing of resources), which translates into significant cost savings for the network providers. / <p>QC 20161115</p>

Even though a community college library rarely attempts to offer the same depth of support found at a university, it can still serve the needs of local graduate students in two ways: through the library’s core collection of print and electronic resources, and through its on-site services, spaces, and librarian expertise. Graduate students need to know that these resources are available to them. The knowledge and ability of the librarian is key to supporting this patron group. This article is informed by the author’s experiences at the College of DuPage, a large comprehensive community college in northeastern Illinois.