1,310 research outputs found

    Implementing centralised IT service management: drawing lessons from the public sector

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    [Abstract]: The IT service management model represents a paradigm shift for IT organisations as it deemphasizes the management of IT assets and focuses on the provision of quality end-to-end IT services. This paper presents part of an in-depth study that examines the experience of a government agency, Queensland Health, in the implementation of a centralised IT service management model based on the ITIL framework. The paper sheds light on the challenges and breakthroughs, distils a set of critical success factors and offers a learning opportunity for other organisations. Outsourcing some activities and tool requirements to vendors was seen as one contributor to success although ensuring effective technology transfer to in-house staff was also necessary. Another success factor was centralisation of IT services. Commitment of senior management was also crucial as was a recognition of the need for effective change management to transform the organisational culture to a service-oriented focus

    DKVF: A Framework for Rapid Prototyping and Evaluating Distributed Key-value Stores

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    We present our framework DKVF that enables one to quickly prototype and evaluate new protocols for key-value stores and compare them with existing protocols based on selected benchmarks. Due to limitations of CAP theorem, new protocols must be developed that achieve the desired trade-off between consistency and availability for the given application at hand. Hence, both academic and industrial communities focus on developing new protocols that identify a different (and hopefully better in one or more aspect) point on this trade-off curve. While these protocols are often based on a simple intuition, evaluating them to ensure that they indeed provide increased availability, consistency, or performance is a tedious task. Our framework, DKVF, enables one to quickly prototype a new protocol as well as identify how it performs compared to existing protocols for pre-specified benchmarks. Our framework relies on YCSB (Yahoo! Cloud Servicing Benchmark) for benchmarking. We demonstrate DKVF by implementing four existing protocols --eventual consistency, COPS, GentleRain and CausalSpartan-- with it. We compare the performance of these protocols against different loading conditions. We find that the performance is similar to our implementation of these protocols from scratch. And, the comparison of these protocols is consistent with what has been reported in the literature. Moreover, implementation of these protocols was much more natural as we only needed to translate the pseudocode into Java (and add the necessary error handling). Hence, it was possible to achieve this in just 1-2 days per protocol. Finally, our framework is extensible. It is possible to replace individual components in the framework (e.g., the storage component)

    Pipeline Task Scheduling with Appication to Network Processors

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    Chip Multi-Processors (CMPs) are now available in a variety of systems and provide the opportunity for achieving high computational performance by exploiting application-level parallelism. In the communications environment, network processors (NPs), designed around CMP architectures, are generally usable in a pipelined manner. This leads to the need for static scheduling of tasks on processor pipelines. This thesis considers problems associated with determining optimal schedules for such pipelines. A collection of algorithms is presented with their utility determined by the size and other characteristics of the system. The algorithms employ heuristics, dynamic programming and statistical methods to schedule tasks derived from multiple application flows on pipelines with an arbitrary number of stages. Experimental results indicate that while the dynamic programming algorithm obtains the optimal schedules, heuristics and statistical methods obtain schedules within 10% of the optimal, 95% of the time. Examples are given to show the use of these algorithms for general pipeline/algorithm design and for use in the Network Processor environment with typical networking applications

    Implementing Centralised IT Service Management: Drawing Lessons from the Public Sector

    Get PDF
    The IT service management model represents a paradigm shift for IT organisations as it deemphasizes the management of IT assets and focuses on the provision of quality end-to-end IT services. This paper presents part of an in-depth study that examines the experience of a government agency, Queensland Health, in the implementation of a centralised IT service management model based on the ITIL framework. The paper sheds light on the challenges and breakthroughs, distils a set of critical success factors and offers a learning opportunity for other organisations. Outsourcing some activities and tool requirements to vendors was seen as one contributor to success although ensuring effective technology transfer to in-house staff was also necessary. Another success factor was centralisation of IT services. Commitment of senior management was also crucial as was a recognition of the need for effective change management to transform the organisational culture to a service-oriented focus

    Object-based Control/Data-flow Analysis

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    Not only does a clear distinction between control and data flow enhance the readability of models, but it also allows different tools to operate on the two distinct parts of the model. This paper shows how the modelling based on control/data-flow analysis can benefit from an object-based approach. We have developed a translation mechanism that is faithful and gives an extra dimension (hierarchy) to the existing paradigm of control and data flow interacting in a model. Our methodology provides a comprehensible separation of these two parts, which can be used to feed another analysis or synthesis tools, while still being able to reason about both parts through formal methods of verification

    A documentation paradigm for an integrated software maintenance support environment

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    Recent advances in computer hardware have not been matched by comparable advances in computer software, inhibiting the production of reliable software at greater levels of productivity. Development of software is restricted by the so-called "maintenance backlog". Productivity in the maintenance sector has not kept pace with increasing annual labour costs, making the maintenance of software the major item in the budget, of organisations responsible for the development and maintenance of software. Gains in productivity can be anticipated by the exploitation of software-maintenance tools, within the framework of an Integrated .Software Maintenance Support Environment (ISMSE). for which a high-level design has been proposed in this thesis, offering comprehensive support for all phases of the software life-cycle, particularly the maintenance phase. A key factor in the reliable modification of software is the time taken to gain the prerequisite understanding, by a study of the system's documentation. This documentation degrades over a period of time, becoming unreliable, inhibiting maintenance of the software, which may be a large capital asset, ultimately, the software may become impossible to maintain, requiring replacement. Understanding gained during maintenance is wide-ranging and at various levels of abstraction, but is often NOT well-recorded, since no effective documentation system exists for recording the maintenance history of large software systems. The documentation paradigm in this thesis, used within the framework of an ISMSE, aims to provide a means of recording the knowledge gained during maintenance, facilitating easier future maintenance, and preserving the reliability of the documentation, so reducing the time required to gain an understanding of the software being maintained. This provides a powerful means of increasing productivity, while simultaneously preserving a valuable capital asset

    Program equipment for automation task simulation

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    Tato diplomová práce popisuje a porovnává vybraný počítačový software, jenž lze využít k modelování automatizačních úloh. Práce je rozdělena na několik částí podle využití jednotivých software v různých odvětvích automatizace.This diploma thesis paints and confronts chosen computer sofware, that we can use for automation task simulation. The thesis is separate into a few parts by kind of usage separate software in diffrent kinds of automation.

    The Second NASA Formal Methods Workshop 1992

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    The primary goal of the workshop was to bring together formal methods researchers and aerospace industry engineers to investigate new opportunities for applying formal methods to aerospace problems. The first part of the workshop was tutorial in nature. The second part of the workshop explored the potential of formal methods to address current aerospace design and verification problems. The third part of the workshop involved on-line demonstrations of state-of-the-art formal verification tools. Also, a detailed survey was filled in by the attendees; the results of the survey are compiled

    Performance analysis under finite load and improvements for multirate 802.11

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    Automatic rate adaptation in CSMA/CA wireless networks may cause drastic throughput degradation for high speed bit rate stations (STAs). The CSMA/CA medium access method guarantees equal long-term channel access probability to all hosts when they are saturated. In previous work it has been shown that the saturation throughput of any STA is limited by the saturation throughput of the STA with the lowest bit rate in the same infrastructure. In order to overcome this problem, we ¯rst introduce in this paper a new model for ¯nite load sources with multirate capabilities. We use our model to investigate the throughput degradation outside and inside the saturation regime. We de¯ne a new fairness index based on the channel occupation time to have more suitable de¯nition of fairness in multirate environments. Further, we propose two simple but powerful mechanisms to partly bypass the observed decline in performance and meet the proposed fairness. Finally, we use our model for ¯nite load sources to evaluate our proposed mechanisms in terms of total throughput and MAC layer delay for various network con¯gurations
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