Resource sharing is considered to be one of the most important pillars of library service, because no single library can meet all the needs of its users. Libraries have always cooperated to meet the increasing demands of users by sharing their resources. In the past few decades, the need to establish library consortia emerged more strongly as libraries began to take advantage of technology to improve access to information and service delivery. There has been a notable increase in the formation of library consortia on the African continent. South Africa has taken the lead both in the amount of established consortia and the number of member libraries within them. This development accompanied the implementation of common library systems in consortia, where a single system is adopted by all member libraries. In the Southern African region, the library system called INNOPAC/Millennium Pac has already been adopted by consortia and libraries in Botswana, Mozambique, Namibia, South Africa, and Zimbabwe. The recently-established Lesotho Library Consortium (LELICO) also recognized the need for a comprehensive investigation to identify a common system that will effectively meet the needs of its member libraries. The purpose of this study was to analyze the successes and limitations of the INNOPAC library system operating in consortia and libraries in the Southern African region, in order to assess its suitability for LELICO. The study focused on two South African consortia (The Gauteng and Environs Library Consortium – GAELIC, and The Free State Library and Information Consortium - FRELICO), two university libraries (Namibia and Zimbabwe) and one agricultural college library (Botswana) in the Southern African region that use the system. A special emphasis was the criteria of assessment that would apply to a small, multi-type consortium in a developing country like Lesotho. Data was collected through a literature search, questionnaires, interviews, site visits, and analysis of policy and institutional documents. The target groups of the study were the library managers, system managers, and library professionals of selected GAELIC and FRELICO libraries, and the system managers of the three selected libraries in the region. The study found that the INNOPAC library system is performing satisfactorily in the chosen consortia and libraries, and that it has a positive impact on them. It performed to a high standard in all the key areas, and this may be attributed to keeping abreast of the latest developments in the library world, and offering a range of services that meet the needs of libraries. The study found further that the INNOPAC library system contributed towards increased productivity, improved customer services, and better decision making in the two consortia. However, direct access to members’ holdings was restricted by a decentralized server model adopted by these consortia. This and other lessons shaped a proposal for the implementation and management of the INNOPAC library system in LELICO. A proposed model recommends a central server as a more cost-effective management solution. The model also explains the mode of operation by member libraries and the coordinated structures that would implement and manage the INNOPAC library system, adapted to the specific requirements of a small, multi-type consortium in a developing country like Lesotho. Given its successful performance in consortia and libraries across Southern African countries, the study recommends further research into the advantages and challenges of INNOPAC for wider regional library cooperation. / Thesis (DPhil)--University of Pretoria, 2009. / Information Science / unrestricted

Dans ce travail, notre contribution est double. Nous développons un cadre d’apprentissage stochastique distribué pour la recherche des équilibres de Nash dans le cas de fonctions de paiement dépendantes d’un état. La plupart des travaux existants supposent qu’une expression analytique de la récompense est disponible au niveau des noeuds. Nous considérons ici une hypothèse réaliste où les noeuds ont seulement une réalisation quantifiée de la récompense à chaque instant et développons un modèle stochastique d’apprentissage à temps discret utilisant une perturbation en sinus. Nous examinons la convergence de notre algorithme en temps discret pour une trajectoire limite définie par une équation différentielle ordinaire (ODE). Ensuite, nous effectuons une analyse de la stabilité et appliquons le schéma proposé dans un problème de commande de puissance générique dans les réseaux sans fil. Nous avons également élaboré un cadre de partage de ressources distribuées pour les réseaux –cloud– en nuage. Nous étudions la stabilité de l’évolution de l’équilibre de Nash en fonction du nombre d’utilisateurs. Dans ce scénario, nous considérons également le comportement des utilisateurs sociaux. Enfin nous avons également examiné un problème de satisfaction de la demande où chaque utilisateur a une demande propre à lui qui doit être satisfaite / As systems are becoming larger, it is becoming difficult to optimize them in a centralized manner due to insufficient backhaul connectivity and dynamical systems behavior. In this thesis, we tackle the above problem by developing a distributed strategic learning framework for seeking Nash equilibria under state dependent payoff functions. We develop a discrete time stochastic learning using sinus perturbation with the realistic assumption, that each node only has a numerical realization of the payoff at each time. We examine the convergence of our discrete time algorithm to a limiting trajectory defined by an ordinary differential equation (ODE). Finally, we conduct a stability analysis and apply the proposed scheme in a generic wireless networks. We also provide the application of these algorithms to real world resource utilization problems in wireless. Our proposed algorithm is applied to the following distributed optimization problems in wireless domain. Power control, beamforming and Bayesian density tracking in the interference channel. We also consider resource sharing problems in large scale networks (e.g. cloud networks) with a generalized fair payoff function. We formulate the problem as a strategic decision-making problem (i.e. a game). We examine the resource sharing game with finite and infinite number of players. Exploiting the aggregate structure of the payoff functions, we show that, the Nash equilibrium is not an evolutionarily stable strategy in the finite regime. Then, we introduce a myopic mean-field response where each player implements a mean-field-taking strategy. We show that such a mean-field-taking strategy is evolutionarily stable in both finite and infinite regime. We provide closed form expression of the optimal pricing that gives an efficient resource sharing policy. As the number of active players grows without bound, we show that the equilibrium strategy converges to a mean-field equilibrium and the optimal prices for resources converge to the optimal price of the mean-field game. Then, we address the demand satisfaction problem for which a necessary and sufficiency condition for satisfactory solutions is provided

Although high-level synthesis has been researched for many years, synthesizing minimum hardware implementations under a throughput constraint for computationally intensive algorithms remains a challenge. In this thesis, three important techniques are studied carefully and applied in an integrated way to meet this challenging synthesis requirement. The first is pipeline scheduling, which generates a pipelined schedule that meets the throughput requirement. The second is module selection, which decides the most appropriate circuit module for each operation. The third is resource sharing, which reuses a circuit module by sharing it between multiple operations. This work shows that combining module selection and resource sharing while performing pipeline scheduling can significantly reduce the hardware area, by either using slower, more area-efficient circuit modules or by time-multiplexing faster, larger circuit modules, while meeting the throughput constraint. The results of this work show that the combined approach can generate on average 43% smaller hardware than possible when a single technique (resource sharing or module selection) is applied. There are four major contributions of this work. First, given a fixed throughput constraint, it explores all feasible frequency and data introduction interval design points that meet this throughput constraint. This enlarged pipelining design space exploration results in superior hardware architectures than previous pipeline synthesis work because of the larger sapce. Second, the module selection algorithm in this work considers different module architectures, as well as different pipelining options for each architecture. This not only addresses the unique architecture of most FPGA circuit modules, it also performs retiming at the high-level synthesis level. Third, this work proposes a novel approach that integrates the three inter-related synthesis techniques of pipeline scheduling, module selection and resource sharing. To the author's best knowledge, this is the first attempt to do this. The integrated approach is able to identify more efficient hardware implementations than when only one or two of the three techniques are applied. Fourth, this work proposes and implements several algorithms that explore the combined pipeline scheduling, module selection and resource sharing design space, and identifies the most efficient hardware architecture under the synthesis constraint. These algorithms explore the combined design space in different ways which represents the trade off between algorithm execution time and the size of the explored design space.

Clonal plants may be able to cope with spatial heterogeneity due to the physiological integration of ramets. Previous studies demonstrated that benefits of clonal integration increase with patch contrast between individual ramets. However, the same magnitude of contrast may be perceived differently in rich and poor environments. According to the theoretical work of Caraco and Kelly (1991), I expected these benefits to be the greatest in overall poor conditions and high between-patch contrast. To test this hypothesis, I conducted experiments with pairs of ramets of a stoloniferous grass, Agrostis stolonifera, grown in variously nutrient rich conditions. The experiment with pairs of ramet of similar developmental age showed only very weak effect of integration on growth of ramets, although integration significantly improved survival of ramets and also affected root-shoot ratio of ramets. Nevertheless, there were considerable benefits of integration in the experiment with developmentally older mother ramets and their daughter ramets. Contrary to the predictions, the benefits of integration were bigger in rich conditions and they decreased with increasing between-patch contrast. In addition, effect of integration on root-shoot ratio of ramets was opposite to the expected specialization for acquisition...

With the expansion of the Internet communication and related availability of increasing number of services built on different technologies, distributed systems represent a solution to integrate these network services and provide them to users in a coherent form. The .NET Framework which provides an environment for application development in a highly distributed environment of Internet and intranet can be used to achieve this goal. This PhD thesis deals with access to shared resources in the context of distributed systems using the .NET platform. The first part of the work is devoted to describing the basic principles of distributed systems and .NET platform techniques, which can be used for implementation of the principles. For the purposes of request processing having asynchronous nature not only in distributed systems a universal interface for the description of asynchronous operations was designed and implemented. The interface extends standard asynchronous techniques on the .NET platform. In order to address the issue of access to shared resources model was designed based on the principles of object-oriented programming, along with basic algorithm to avoid deadlock in the case of use resources by multiple processes (threads) simultaneously. This extendable model has been successfully implemented and its functionality verified in basic scenarios of access to shared resources. After the definition of resources and their dependencies the implemented model allows working with resources as with any other objects on .NET platform. The synchronization processes proceed transparently in background.

The project aims at solving the problem of non-repudiation, integrity and confidentiality of data when digitally exchanging sensitive resources between parties that need to be able to trust each other without the need for a trusted third party. This is done in the framework of answering to what extent digital resources can be shared securely in a decentralized public ledger-based system compared to trust-based alternatives. A background of existing resource sharing solutions is explored which shows an abundance third party trust-based systems, but also an interest in public ledger solutions in the form of the Storj network which uses such technology, but focuses on storage rather than sharing. The proposed solution, called SecuRES, is a communication protocol based on public ledger technology which acts similar to Bitcoin. A prototype based on the protocol has been implemented which proves the ability to share encrypted files with one or several recipients through a decentralized public ledger-based network. It was concluded that the SecuRES solution could do away with the requirement of trust in third parties for all but some optional operations using external authentication services. This is done while still maintaining data integrity of a similar or greater degree to trust-based solutions and offers the additional benefits of non-repudiation, high confidentiality and high transparency from the ability to make source code and protocol documentation openly available without endangering the system. Further research is needed to investigate whether the system can scale up for widespread adoption while maintaining security and reasonable performance requirements. / Projektet ämnar lösa problemen med oförnekbarhet, integritet och konfidentialitet när man delar känsligt data mellan parter som behöver lita på varandra utan inblanding av betrodd tredje part. Detta diskuteras för att besvara till vilken omfattning digitala resurser kan delas säkert i ett decentraliserat system baserat på publika liggare jämfört med existerande tillitsbaserade alternativ. En undersökning av nuvarande resursdelningslösningar visar att det existerar många tillitsbaserade system men även en växande andel lösningar baserade på publika liggare. En intressant lösning som lyfts fram är Storj som använder sådan teknologi men fokuserar på resurslagring mer är delning. Projektets föreslagna lösning, kallad SecuRES, är ett kommunikationsprotokoll baserat på en publik liggare likt Bitcoin. En prototyp baserad på protokollet har tagits fram som visar att det är möjligt att dela krypterade filer med en eller flera mottagare genom ett decentraliserat nätverk baserat på publika liggare. Slutsatsen som dras är att SecuRES klarar sig utan betrodda tredje parter för att dela resurser medan vissa operationer kan göras mer användarvänliga genom externa autentiseringstjänster. Själva lösningen garanterar integritet av data och medför ytterligare fördelar såsom oförnekbarhet, konfidentialitet och hög transparens då man kan göra källkoden och protocoldokumentation fritt läsbar utan att utsätta systemet för fara. Vidare forskning behövs för att undersöka om systemet kan skalas upp för allmän användning och alltjämt bibehålla säkerhets- samt prestandakrav.

Universities in the new millennium find themselves in a knowledge-driven economy that is challenging them to produce a qualified and adaptable work force if they are to contribute to societal development. Owing to the structural change in the economy, entrepreneurs require high level scientists, professionals and technicians who not only have the capability to create and support innovations by adapting knowledge to local use but also people with managerial and lifelong learning skills. Such are they who can accelerate changes and make organizations more productive and efficient in the services they render. Consequently, universities in Sub-Saharan Africa are challenged to transform learning so as to produce graduates who have both knowledge and competencies. Such a system will create a balance between university education and the changing labour market. Satisfying these new educational demands are only possible through research and unhindered access to global information resources. Paradoxically, some private university libraries, because of limited funding, find themselves fiscally constrained in the provision of unhindered access to global stores of information particularly at a time of exponential growth both in number and cost of information resources. This had led libraries to re-examine resource sharing as a viable option to meeting the new demands placed on universities. It is for the reasons above that this study examines the practice, problems and prospects of resource-sharing in selected Seventh-day Adventist university libraries in Sub-Saharan Africa. It examines scientifically the causes of poor sharing practices that are unique to each library, the situational and environmental factors that can enhance resource sharing. It provides also research-based information that will help to determine the best ways by which each library can have greater access to information resources. There are proposals for resolving the problems, and there are recommendations for dealing with the matter on a more permanent basis. The study advances resource-sharing model called Consortium of Adventist University Libraries in Africa (CAULA) as a resource sharing network for Seventh-day Adventist libraries in Africa. The organizational structure for CAULA are outlined and discussed. The proposed cooperation is not only sustainable but also structured to provide efficiency and greater regional cooperation of SDA libraries in Sub-Saharan Africa. / Information Science / DLITT ET PHIL (INF SCIENCE)

Library automation is approaching its 90th birthday (deduced from Pace, 2009:1), and many librarians no longer remember the inefficiencies of the manual systems that were previously in place. For some, however, automation has not gone nearly far enough. In this second decade of the new millennium some libraries in Lesotho face multiple challenges in automating their services while libraries internationally are staying relevant by rapidly adapting their services to address the needs and demands of the clients. It was anticipated that full library automation is a prerequisite for delivering 21st-century library services and the researcher embarked on a process to establish whether libraries belonging to the Lesotho Library Consortium (LELICO) have automated to the extent where they will be able to provide the services that are currently in demand. The purpose of this study was to analysewhether full library automation is indeed a prerequisite for libraries to offer the services required in the current millennium. The study focused on LELICO member libraries. Benchmarking was done with selected South African academic libraries. Data were collected by means of interviews with all respondents, namely, LELICO member libraries, librarians from South African libraries and with international system vendors operating from South Africa. The study found that LELICO member libraries are indeed lagging behindin terms of service provision. LELICO member libraries do not appear to understand; which library services are possible when state-of-the-art technology is fully implemented. The study found furthermore that the laggard status is caused by factors such as a lack of funding, too few professional staff and ineffective support from management. These and other findings helped formulate recommendations that would underpin a renewal strategy for LELICO. The proposed recommendations include that LELICO should deliver a more meaningful service to its current members. LELICO member libraries should be using technology more effectively in their operations and good relationship between a system vendor and its clients should be seen as an asset that should be maintained.LELICO should be playing a key role in making change a reality. / Information Science / M.A. (Information Science)

In this thesis we have tackled a few scheduling problems under energy constraint, since the energy issue is becoming crucial, for both economical and environmental reasons. In the first chapter, we exhibit tight bounds on the energy metric of a classical algorithm that minimizes the makespan of independent tasks. In the second chapter, we schedule several independent but concurrent pipelined applications and address problems combining multiple criteria, which are period, latency and energy. We perform an exhaustive complexity study and describe the performance of new heuristics. In the third chapter, we study the replica placement problem in a tree network. We try to minimize the energy consumption in a dynamic frame. After a complexity study, we confirm the quality of our heuristics through a complete set of simulations. In the fourth chapter, we come back to streaming applications, but in the form of series-parallel graphs, and try to map them onto a chip multiprocessor. The design of a polynomial algorithm on a simple problem allows us to derive heuristics on the most general problem, whose NP-completeness has been proven. In the fifth chapter, we study energy bounds of different routing policies in chip multiprocessors, compared to the classical XY routing, and develop new routing heuristics. In the last chapter, we compare the performance of different algorithms of the literature that tackle the problem of mapping DAG applications to minimize the energy consumption.

Universities in the new millennium find themselves in a knowledge-driven economy that is challenging them to produce a qualified and adaptable work force if they are to contribute to societal development. Owing to the structural change in the economy, entrepreneurs require high level scientists, professionals and technicians who not only have the capability to create and support innovations by adapting knowledge to local use but also people with managerial and lifelong learning skills. Such are they who can accelerate changes and make organizations more productive and efficient in the services they render. Consequently, universities in Sub-Saharan Africa are challenged to transform learning so as to produce graduates who have both knowledge and competencies. Such a system will create a balance between university education and the changing labour market. Satisfying these new educational demands are only possible through research and unhindered access to global information resources. Paradoxically, some private university libraries, because of limited funding, find themselves fiscally constrained in the provision of unhindered access to global stores of information particularly at a time of exponential growth both in number and cost of information resources. This had led libraries to re-examine resource sharing as a viable option to meeting the new demands placed on universities. It is for the reasons above that this study examines the practice, problems and prospects of resource-sharing in selected Seventh-day Adventist university libraries in Sub-Saharan Africa. It examines scientifically the causes of poor sharing practices that are unique to each library, the situational and environmental factors that can enhance resource sharing. It provides also research-based information that will help to determine the best ways by which each library can have greater access to information resources. There are proposals for resolving the problems, and there are recommendations for dealing with the matter on a more permanent basis. The study advances resource-sharing model called Consortium of Adventist University Libraries in Africa (CAULA) as a resource sharing network for Seventh-day Adventist libraries in Africa. The organizational structure for CAULA are outlined and discussed. The proposed cooperation is not only sustainable but also structured to provide efficiency and greater regional cooperation of SDA libraries in Sub-Saharan Africa. / Information Science / DLITT ET PHIL (INF SCIENCE)