Towards Autonomic Service Provisioning Systems

This paper discusses our experience in building SPIRE, an autonomic system for service provision. The architecture consists of a set of hosted Web Services subject to QoS constraints, and a certain number of servers used to run session-based traffic. Customers pay for having their jobs run, but require in turn certain quality guarantees: there are different SLAs specifying charges for running jobs and penalties for failing to meet promised performance metrics. The system is driven by an utility function, aiming at optimizing the average earned revenue per unit time. Demand and performance statistics are collected, while traffic parameters are estimated in order to make dynamic decisions concerning server allocation and admission control. Different utility functions are introduced and a number of experiments aiming at testing their performance are discussed. Results show that revenues can be dramatically improved by imposing suitable conditions for accepting incoming traffic; the proposed system performs well under different traffic settings, and it successfully adapts to changes in the operating environment.Comment: 11 pages, 9 Figures, http://www.wipo.int/pctdb/en/wo.jsp?WO=201002636

Mining association rules for admission control and service differentiation in e-commerce applications

Workload demands in e-commerce applications are very dynamic in nature, therefore it is essential for internet service providers to manage server resources effectively to maximise total revenue in server overloading situations. In this paper, a data mining technique is applied to a typical e-commerce application model for identification of composite association rules that capture user navigation patterns. Two algorithms are then developed based on the derived rules for admission control, service differentiation and priority scheduling. Our approach takes the following into consideration: a) only final purchase requests result in company revenue; b) any other request can potentially lead to a final purchase, depending upon the likelihood of the navigation sequence that starts from current request and leads to final purchase; c) service differentiation and priority assignment are based on aggregated confidence and average support of the composite association rules. As identification of composite association rules and computation of confidence and support of the rules can be pre-computed offline, the proposed approach incurs minimum performance overheads. The evaluation results suggest that the proposed approach is effective in terms of request management for revenue maximisation

Economic impact of energy saving techniques in cloud server

In recent years, lot of research has been carried in the field of cloud computing and distributed systems to investigate and understand their performance. Economic impact of energy consumption is of major concern for major companies. Cloud Computing companies (Google, Yahoo, Gaikai, ONLIVE, Amazon and eBay) use large data centers which are comprised of virtual computers that are placed globally and require a lot of power cost to maintain. Demand for energy consumption is increasing day by day in IT firms. Therefore, Cloud Computing companies face challenges towards the economic impact in terms of power costs. Energy consumption is dependent upon several factors, e.g., service level agreement, virtual machine selection techniques, optimization policies, workload types etc. We address a solution for the energy saving problem by enabling dynamic voltage and frequency scaling technique for gaming data centers. The dynamic voltage and frequency scaling technique is compared against non-power aware and static threshold detection techniques. This helps service providers to meet the quality of service and quality of experience constraints by meeting service level agreements. The CloudSim platform is used for implementation of the scenario in which game traces are used as a workload for testing the technique. Selection of better techniques can help gaming servers to save energy cost and maintain a better quality of service for users placed globally. The novelty of the work provides an opportunity to investigate which technique behaves better, i.e., dynamic, static or non-power aware. The results demonstrate that less energy is consumed by implementing a dynamic voltage and frequency approach in comparison with static threshold consolidation or non-power aware technique. Therefore, more economical quality of services could be provided to the end users

Master of Science

thesisHuman-environment interaction has long been a primary theme of geographic thought. Public lands policies, and particularly wilderness designations, significantly shape the natural environment in western states such as Utah. Geographic information science and the Internet are now important parts of the policy-making toolkit, replacing paper maps and potentially leading to more democratization of wilderness and other important, long-term land use decisions. Geographical concepts such as regions are often employed in public land debates. Nongeographers have driven many of these developments. The goal of this research is to demonstrate a simple, low-cost, and accurate geographic information system (GIS) using an open-source approach and freely distributable datasets. The online Utah Wilderness Atlas will provide spatial and descriptive wildlands resource information to a general audience. It is now easier than ever to produce and exchange geospatial data; however, such data can still be difficult to use. Datasets vary in accuracy, source scale, and spatial extent and may be poorly documented. Casual users may not know where to look for the most appropriate or reliable data, and they may not have the skills or the computer software to convert specialized file formats into meaningful maps. The Utah Wilderness Atlas provides maps that can be read with a standard Web browser

EMMON - EMbedded MONitoring

Despite the steady increase in experimental deployments, most of research work on WSNs has focused only on communication protocols and algorithms, with a clear lack of effective, feasible and usable system architectures, integrated in a modular platform able to address both functional and non–functional requirements. In this paper, we outline EMMON [1], a full WSN-based system architecture for large–scale, dense and real–time embedded monitoring [3] applications. EMMON provides a hierarchical communication architecture together with integrated middleware and command and control software. Then, EM-Set, the EMMON engineering toolset will be presented. EM-Set includes a network deployment planning, worst–case analysis and dimensioning, protocol simulation and automatic remote programming and hardware testing tools. This toolset was crucial for the development of EMMON which was designed to use standard commercially available technologies, while maintaining as much flexibility as possible to meet specific applications requirements. Finally, the EMMON architecture has been validated through extensive simulation and experimental evaluation, including a 300+ nodes testbed

Improving School Improvement

PREFACEIn opening this volume, you might be thinking:Is another book on school improvement really needed?Clearly our answer is yes. Our analyses of prevailing school improvement legislation, planning, and literature indicates fundamental deficiencies, especially with respect to enhancing equity of opportunity and closing the achievement gap.Here is what our work uniquely brings to policy and planning tables:(1) An expanded framework for school improvement – We highlight that moving from a two- to a three-component policy and practice framework is essential for closing the opportunity and achievement gaps. (That is, expanding from focusing primarily on instruction and management/government concerns by establishing a third primary component to improve how schools address barriers to learning and teaching.)(2) An emphasis on integrating a deep understanding of motivation – We underscore that concerns about engagement, management of behavior, school climate, equity of opportunity, and student outcomes require an up-to-date grasp of motivation and especially intrinsic motivation.(3) Clarification of the nature and scope of personalized teaching – We define personalization as the process of matching learner motivation and capabilities and stress that it is the learner's perception that determines whether the match is a good one.(4) A reframing of remediation and special education – We formulate these processes as personalized special assistance that is applied in and out of classrooms and practiced in a sequential and hierarchical manner.(5) A prototype for transforming student and learning supports – We provide a framework for a unified, comprehensive, and equitable system designed to address barriers to learning and teaching and re-engage disconnected students and families.(6) A reworking of the leadership structure for whole school improvement --We outline how the operational infrastructure can and must be realigned in keeping with a three component school improvement framework.(7) A systemic approach to enhancing school-community collaboration – We delineate a leadership role for schools in outreaching to communities in order to work on shared concerns through a formal collaborative operational infrastructure that enables weaving together resources to advance the work.(8) An expanded framework for school accountability – We reframe school accountability to ensure a balanced approach that accounts for a shift to a three component school improvement policy.(9) Guidance for substantive, scalable, and sustainable systemic changes –We frame mechanisms and discuss lessons learned related to facilitating fundamental systemic changes and replicating and sustaining them across a district.The frameworks and practices presented are based on our many years of work in schools and from efforts to enhance school-community collaboration. We incorporate insights from various theories and the large body of relevant research and from lessons learned and shared by many school leaders and staff who strive everyday to do their best for children.Our emphasis on new directions in no way is meant to demean current efforts. We know that the demands placed on those working in schools go well beyond what anyone should be asked to do. Given the current working conditions in many schools, our intent is to help make the hard work generate better results. To this end, we highlight new directions and systemic pathways for improving school outcomes.Some of what we propose is difficult to accomplish. Hopefully, the fact that there are schools, districts, and state agencies already trailblazing the way will engender a sense of hope and encouragement to those committed to innovation.It will be obvious that our work owes much to many. We are especially grateful to those who are pioneering major systemic changes across the country. These leaders and so many in the field have generously offered their insights and wisdom. And, of course, we are indebted to hundreds of scholars whose research and writing is a shared treasure. As always, we take this opportunity to thank Perry Nelson and the host of graduate and undergraduate students at UCLA who contribute so much to our work each day, and to the many young people and their families who continue to teach us all.Respectfully submitted for your consideration,Howard Adelman & Linda Taylo

Nas nuvens ou fora delas, eis a questão

Mestrado em Sistemas de InformaçãoO proposito desta dissertação é contribuir no sentido de uma melhor compreensão sobre a decisão de ir ou não ir para uma solução na cloud quando uma organização é confrontada com a necessidade de criar ou expandir um sistema de informação. Isto é feito recorrendo à identificação de factores técnicos e económicos que devem ser tomados em conta quando planeamos uma nova solução e desenvolver um framework para ajudar os decisores. Os seguintes aspetos são considerados: • Definição de um modelo de referência genérico para funcionalidades de um Sistemas de Informação. • Identificação de algumas métricas básicas para caracterizar performance e custos de Sistemas de Informação. • Analise e caracterização de Sistemas de Informação on-premises: Arquiteturas Elementos de custo Questões de Performance • Analise e caracterização de Sistemas de Informação Cloud: Topologias Estruturas de custo Questões de Performance • Estabelecimento de framework de comparação para a cloud versus on-premises • Casos de uso comparando soluções na cloud e on-premises; • Produção de guidelines (focadas no caso das clouds publicas) Para ilustrar o procedimento, são usados dois business cases, ambos com duas abordagens: uma dedicada aos Profissionais de IT (abordagem técnica), outra aos Gestores/Decisores (abordagem económica).The purpose of this dissertation is to contribute towards a better understanding about the decision to go or not to go for cloud solutions when an organization is confronted with the need to create or enlarge an information system. This is done resorting to the identification of technical and economic factors that must be taken into account when planning a new solution and developing a framework to help decision makers. The following aspects are considered: • Definition of a generic reference model for Information systems functionalities. • Identification of some basic metrics characterizing information systems performance. • Analysis and characterization of on-premisis information systems: Architectures Cost elements Performance issues • Analysis and characetrization of cloud information systems. Typology Cost structures Performance issues • Establishment of a comparison framework for cloud versus on-premises solutions as possible instances of information systems. • Use cases comparing cloud and on-premises solutions. • Production of guidelines (focus on public cloud case) To illustrate the procedure, two business cases are used, both with two approaches: one dedicated to IT Professionals (Technical approach), other to Managers/Decision Makers (Economic approach)

Exploring Czechs' and Greeks' mental associations of London: a tourist destination or a place to live in?

Existing literature on multiple place image domains is sparse with a notable lack of research on the extent to which the various images can be separated in the minds of individuals, and potential interrelationships among them. This study seeks to identify commonalities and divergences in the dimensions of image as a tourist destination and as a place to live in, from the outsider perspective, and explore how these two distinct representations of the same place can co-exist in peoples’ mind. Data were collected using 42 semi-structured interviews with Czech and Greek residents. Findings suggest that the two image domains share very similar image dimensions but are clearly differentiated in peoples’ mind as a result of identity salience. Destination image appears also to serve as a platform shaping peoples’ images of a locale as a place to live. The findings provide a comprehensive understanding of the notion of place image and have implications for place marketing