110 research outputs found

    Machine Learning

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    Machine Learning can be defined in various ways related to a scientific domain concerned with the design and development of theoretical and implementation tools that allow building systems with some Human Like intelligent behavior. Machine learning addresses more specifically the ability to improve automatically through experience

    Investigations into Elasticity in Cloud Computing

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    The pay-as-you-go model supported by existing cloud infrastructure providers is appealing to most application service providers to deliver their applications in the cloud. Within this context, elasticity of applications has become one of the most important features in cloud computing. This elasticity enables real-time acquisition/release of compute resources to meet application performance demands. In this thesis we investigate the problem of delivering cost-effective elasticity services for cloud applications. Traditionally, the application level elasticity addresses the question of how to scale applications up and down to meet their performance requirements, but does not adequately address issues relating to minimising the costs of using the service. With this current limitation in mind, we propose a scaling approach that makes use of cost-aware criteria to detect the bottlenecks within multi-tier cloud applications, and scale these applications only at bottleneck tiers to reduce the costs incurred by consuming cloud infrastructure resources. Our approach is generic for a wide class of multi-tier applications, and we demonstrate its effectiveness by studying the behaviour of an example electronic commerce site application. Furthermore, we consider the characteristics of the algorithm for implementing the business logic of cloud applications, and investigate the elasticity at the algorithm level: when dealing with large-scale data under resource and time constraints, the algorithm's output should be elastic with respect to the resource consumed. We propose a novel framework to guide the development of elastic algorithms that adapt to the available budget while guaranteeing the quality of output result, e.g. prediction accuracy for classification tasks, improves monotonically with the used budget.Comment: 211 pages, 27 tables, 75 figure

    Combining SOA and BPM Technologies for Cross-System Process Automation

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    This paper summarizes the results of an industry case study that introduced a cross-system business process automation solution based on a combination of SOA and BPM standard technologies (i.e., BPMN, BPEL, WSDL). Besides discussing major weaknesses of the existing, custom-built, solution and comparing them against experiences with the developed prototype, the paper presents a course of action for transforming the current solution into the proposed solution. This includes a general approach, consisting of four distinct steps, as well as specific action items that are to be performed for every step. The discussion also covers language and tool support and challenges arising from the transformation

    Seventh Biennial Report : June 2003 - March 2005

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    Ecosystemic Evolution Feeded by Smart Systems

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    Information Society is advancing along a route of ecosystemic evolution. ICT and Internet advancements, together with the progression of the systemic approach for enhancement and application of Smart Systems, are grounding such an evolution. The needed approach is therefore expected to evolve by increasingly fitting into the basic requirements of a significant general enhancement of human and social well-being, within all spheres of life (public, private, professional). This implies enhancing and exploiting the net-living virtual space, to make it a virtuous beneficial integration of the real-life space. Meanwhile, contextual evolution of smart cities is aiming at strongly empowering that ecosystemic approach by enhancing and diffusing net-living benefits over our own lived territory, while also incisively targeting a new stable socio-economic local development, according to social, ecological, and economic sustainability requirements. This territorial focus matches with a new glocal vision, which enables a more effective diffusion of benefits in terms of well-being, thus moderating the current global vision primarily fed by a global-scale market development view. Basic technological advancements have thus to be pursued at the system-level. They include system architecting for virtualization of functions, data integration and sharing, flexible basic service composition, and end-service personalization viability, for the operation and interoperation of smart systems, supporting effective net-living advancements in all application fields. Increasing and basically mandatory importance must also be increasingly reserved for human–technical and social–technical factors, as well as to the associated need of empowering the cross-disciplinary approach for related research and innovation. The prospected eco-systemic impact also implies a social pro-active participation, as well as coping with possible negative effects of net-living in terms of social exclusion and isolation, which require incisive actions for a conformal socio-cultural development. In this concern, speed, continuity, and expected long-term duration of innovation processes, pushed by basic technological advancements, make ecosystemic requirements stricter. This evolution requires also a new approach, targeting development of the needed basic and vocational education for net-living, which is to be considered as an engine for the development of the related ‘new living know-how’, as well as of the conformal ‘new making know-how’

    Addressing concerns in performance prediction : the impact of data dependencies and denormal arithmetic in scientific codes

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    To meet the increasing computational requirements of the scientific community, the use of parallel programming has become commonplace, and in recent years distributed applications running on clusters of computers have become the norm. Both parallel and distributed applications face the problem of predictive uncertainty and variations in runtime. Modern scientific applications have varying I/O, cache, and memory profiles that have significant and difficult to predict effects on their runtimes. Data-dependent sensitivities such as the costs of denormal floating point calculations introduce more variations in runtime, further hindering predictability. Applications with unpredictable performance or which have highly variable runtimes can cause several problems. If the runtime of an application is unknown or varies widely, workflow schedulers cannot e�ciently allocate them to compute nodes, leading to the under-utilisation of expensive resources. Similarly, a lack of accurate knowledge of the performance of an application on new hardware can lead to misguided procurement decisions. In heavily parallel applications, minor variations in runtime on individual nodes can have disproportionate effects on the overall application runtime. Even on a smaller scale, a lack of certainty about an application's runtime can preclude its use in real-time or time-critical applications such as clinical diagnosis. This thesis investigates two sources of data-dependent performance variability. The first source is algorithmic and is seen in a state-of-the-art C++ biomedical imaging application. It identifies the cause of the variability in the application and develops a means of characterising the variability. This 'probe task' based model is adapted for use with a workflow scheduler, and the scheduling improvements it brings are examined. The second source of variability is more subtle as it is micro-architectural in nature. Depending on the input data, two runs of an application executing exactly the same sequence of instructions and with exactly the same memory access patterns can have large differences in runtime due to deficiencies in common hardware implementations of denormal arithmetic1. An exception-based profiler is written to detect occurrences of denormal arithmetic and it is shown how this is insufficient to isolate the sources of denormal arithmetic in an application. A novel tool based on theValgrind binary instrumentation framework is developed which can trace the origins of denormal values and the frequency of their occurrence in an application's data structures. This second tool is used to isolate and remove the cause of denormal arithmetic both from a simple numerical code, and then from a face recognition application

    SeaFlows – A Compliance Checking Framework for Supporting the Process Lifecycle

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    Compliance-awareness is undoubtedly of utmost importance for companies nowadays. Even though an automated approach to compliance checking and enforcement has been advocated in recent literature as a means to tame the high costs for compliance-awareness, the potential of automated mechanisms for supporting business process compliance is not yet depleted. Business process compliance deals with the question whether business processes are designed and executed in harmony with imposed regulations. In this thesis, we propose a compliance checking framework for automating business process compliance verification within process management systems (PrMSs). Such process-aware information systems constitute an ideal environment for the systematic integration of automated business process compliance checking since they bring together different perspectives on a business process and provide access to process data. The objective of this thesis is to devise a framework that enhances PrMSs with compliance checking functionality. As PrMSs enable both the design and the execution of business processes, the designated compliance checking framework must accommodate mechanisms to support these different phases of the process lifecycle. A compliance checking framework essentially consists of two major building blocks: a compliance rule language to capture compliance requirements in a checkable manner and compliance checking mechanisms for verification of process models and process instances. Key to the practical application of a compliance checking framework will be its ability to provide comprehensive and meaningful compliance diagnoses. Based on the requirements analysis and meta-analyses, we developed the SeaFlows compliance checking framework proposed in this thesis. We introduce the compliance rule graph (CRG) language for modeling declarative compliance rules. The language provides modeling primitives with a notation based on nodes and edges. A compliance rule is modeled by defining a pattern of activity executions activating a compliance rule and consequences that have to apply once a rule becomes activated. In order to enable compliance verification of process models and process instances, the CRG language is operationalized. Key to this approach is the exploitation of the graph structure of CRGs for representing compliance states of the respective CRGs in a transparent and interpretable manner. For that purpose, we introduce execution states to mark CRG nodes in order to indicate which parts of the CRG patterns can be observed in a process execution. By providing rules to alter the markings when a new event is processed, we enable to update the compliance state for each observed event. The beauty of our approach is that both design and runtime can be supported using the same mechanisms. Thus, no transformation of compliance rules in different representations for process model verification or for compliance monitoring becomes necessary. At design time, the proposed approach can be applied to explore a process model and to detect which compliance states with respect to imposed CRGs a process model is able to yield. At runtime, the effective compliance state of process instances can be monitored taking also the future predefined in the underlying process model into account. As compliance states are encoded based on the CRG structure, fine-grained and intelligible compliance diagnoses can be derived in each detected compliance state. Specifically, it becomes possible to provide feedback not only on the general enforcement of a compliance rule but also at the level of particular activations of the rule contained in a process. In case of compliance violations, this can explain and pinpoint the source of violations in a process. In addition, measures to satisfy a compliance rule can be easily derived that can be seized for providing proactive support to comply. Altogether, the SeaFlows compliance checking framework proposed in this thesis can be embedded into an overall integrated compliance management framework

    Computer-Mediated Communication

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    This book is an anthology of present research trends in Computer-mediated Communications (CMC) from the point of view of different application scenarios. Four different scenarios are considered: telecommunication networks, smart health, education, and human-computer interaction. The possibilities of interaction introduced by CMC provide a powerful environment for collaborative human-to-human, computer-mediated interaction across the globe

    Bioinformatics

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    This book is divided into different research areas relevant in Bioinformatics such as biological networks, next generation sequencing, high performance computing, molecular modeling, structural bioinformatics, molecular modeling and intelligent data analysis. Each book section introduces the basic concepts and then explains its application to problems of great relevance, so both novice and expert readers can benefit from the information and research works presented here
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