18 resultados para data gathering

em Aston University Research Archive


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Energy consumption has been a key concern of data gathering in wireless sensor networks. Previous research works show that modulation scaling is an efficient technique to reduce energy consumption. However, such technique will also impact on both packet delivery latency and packet loss, therefore, may result in adverse effects on the qualities of applications. In this paper, we study the problem of modulation scaling and energy-optimization. A mathematical model is proposed to analyze the impact of modulation scaling on the overall energy consumption, end-to-end mean delivery latency and mean packet loss rate. A centralized optimal management mechanism is developed based on the model, which adaptively adjusts the modulation levels to minimize energy consumption while ensuring the QoS for data gathering. Experimental results show that the management mechanism saves significant energy in all the investigated scenarios. Some valuable results are also observed in the experiments. © 2004 IEEE.

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Ad hoc wireless sensor networks (WSNs) are formed from self-organising configurations of distributed, energy constrained, autonomous sensor nodes. The service lifetime of such sensor nodes depends on the power supply and the energy consumption, which is typically dominated by the communication subsystem. One of the key challenges in unlocking the potential of such data gathering sensor networks is conserving energy so as to maximize their post deployment active lifetime. This thesis described the research carried on the continual development of the novel energy efficient Optimised grids algorithm that increases the WSNs lifetime and improves on the QoS parameters yielding higher throughput, lower latency and jitter for next generation of WSNs. Based on the range and traffic relationship the novel Optimised grids algorithm provides a robust traffic dependent energy efficient grid size that minimises the cluster head energy consumption in each grid and balances the energy use throughout the network. Efficient spatial reusability allows the novel Optimised grids algorithm improves on network QoS parameters. The most important advantage of this model is that it can be applied to all one and two dimensional traffic scenarios where the traffic load may fluctuate due to sensor activities. During traffic fluctuations the novel Optimised grids algorithm can be used to re-optimise the wireless sensor network to bring further benefits in energy reduction and improvement in QoS parameters. As the idle energy becomes dominant at lower traffic loads, the new Sleep Optimised grids model incorporates the sleep energy and idle energy duty cycles that can be implemented to achieve further network lifetime gains in all wireless sensor network models. Another key advantage of the novel Optimised grids algorithm is that it can be implemented with existing energy saving protocols like GAF, LEACH, SMAC and TMAC to further enhance the network lifetimes and improve on QoS parameters. The novel Optimised grids algorithm does not interfere with these protocols, but creates an overlay to optimise the grids sizes and hence transmission range of wireless sensor nodes.

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RFID is one of the contemporary technologies that has the potential to enable improved data gathering and cross-companies integration, and thus achieve cost efficiency. However, RFID has not yet become primary approach to collect data from the supply chain activities. This is partly due to (relative) high cost of implementation, partly due to technical deficiencies, as well as cross-company systems integration issues. This paper discusses a potential application area for RFID technology, which is environmentally sustainable supply chain management. The paper discusses the current practices in green supply chain management, and proposes possible applications of RFID enabling green supply chain management. The paper also proposes an idea of ad hoc RFID systems which are rapidly deployable and require minimal, if at all, pre-existing infrastructure. © 2010 IEEE.

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The research investigates the past, present and potential future role of Information Specialists (ISps) in process oriented companies. It tests the proposition that ISps in companies that have undertaken formal process reengineering exercises are likely to become more proactive and more business oriented (as opposed to technically oriented) than they had previously been when their organisations were organised along traditional, functional lines. A review of existing literature in the area of Business Process Reengineering and Information Management reveals a lack of consensus amongst researchers concerning the appropriate role for ISps during and after BPR. Opinion is divided as to whether IS professionals should reactively support BPR or whether IT/IS developments should be driving these initiatives. A questionnaire based ‘Descriptive Survey’ with 60 respondents is used as a first stage of primary data gathering. This is followed by follow-up interviews with 20 of the participating organisations to gather further information on their experiences. The final stage of data collection consists of further in-depth interview with four case study companies to provide an even richer picture of their experiences. The results of the questionnaire are analysed and displayed in the form of simple means, frequencies and bar graphs. The ‘NU-DIST’ computer based discourse analysis package was tried in relation to summarising the interview findings, but this proved cumbersome and a visual collation method is preferred. Overall, the researcher contends that the supposition outlined above is proven, and she concludes the research by suggesting the implications of these findings. In particular she offers a ‘Framework for Understanding and Action’ which is deemed to be relevant to both practitioners and future researchers.

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Strategic planning and more specifically, the impact of strategic planning on organisational performance has been the subject of significant academic interest since the early 1970's. However, despite the significant amount of previous work examining the relationship between strategic planning and organisational performance, a comprehensive literature review identified a number of areas where contributions to the domain of study could be made. In overview, the main areas for further study identified from the literature review were a) a further examination of both the dimensionality and conceptualisation of strategic planning and organisational performance and b) a further, multivariate, examination of the relationship between strategic planning and performance, to capture the newly identified dimensionality. In addition to the previously identified strategic planning and organisational performance constructs, a comprehensive literature based assessment was undertaken and five main areas were identified for further examination, these were a) organisational b) comprehensive strategic choice, c) the quality of strategic options generated, d) political behavior and e) implementation success. From this, a conceptual model incorporating a set of hypotheses to be tested was formulated. In order to test the conceptual model specified and also the stated hypotheses, data gathering was undertaken. The quantitative phase of the research involved a mail survey of senior managers in medium to large UK based organisations, of which a total of 366 fully useable responses were received. Following rigorous individual construct validity and reliability testing, the complete conceptual model was tested using latent variable path analysis. The results for the individual hypotheses and also the complete conceptual model were most encouraging. The findings, theoretical and managerial implications, limitations and directions for future research are discussed.

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Initially the study focussed on the factors affecting the ability of the police to solve crimes. An analysts of over twenty thousand police deployments revealed the proportion of time spent investigating crime contrasted to its perceived importance and the time spent on other activities. The fictional portrayal of skills believed important in successful crime investigation were identified and compared to the professional training and 'taught skills’ given to police and detectives. Police practitioners and middle management provided views on the skills needed to solve crimes. The relative importance of the forensic science role. fingerprint examination and interrogation skills were contrasted with changes in police methods resulting from the Police and Criminal Evidence Act and its effect on confessions. The study revealed that existing police systems for investigating crime excluding specifically cases of murder and other serious offences, were unsystematic, uncoordinated, unsupervised and unproductive in using police resources. The study examined relevant and contemporary research in the United States and United Kingdom and with organisational support introduced an experimental system of data capture and initial investigation with features of case screening and management. Preliminary results indicated increases in the collection of essential information and more effective use of investigative resources. In the managerial framework within which this study has been conducted, research has been undertaken in the knowledge elicitation area as a basis for an expert system of crime investigation and the potential organisational benefits of utilising the Lap computer in the first stages of data gathering and investigation. The conclusions demonstrate the need for a totally integrated system of criminal investigation with emphasis on an organisational rather than individual response. In some areas the evidence produced is sufficient to warrant replication, in others additional research is needed to further explore other concepts and proposed systems pioneered by this study.

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The thesis addresses the economic impacts of construction safety in Greece. The research involved the development of a methodology for determining the overall costs of safety, namely the sum of the costs of accidents and the costs of safety management failures (with or without accident) including image cost. Hitherto, very little work has been published on the cost of accidents in practical case studies. Moreover, to the author’s belief, no research has been published that seeks to determine in real cases the costs of prevention. The methodology developed is new, transparent, and capable of being replicated and adapted to other employment sectors and to other countries. The methodology was applied to three construction projects in Greece to test the safety costing methodology and to offer some preliminary evidence on the business case for safety. The survey work took place between 1999 and 2001 and involved 27 months of costing work on site. The study focuses on the overall costs of safety that apply to the main (principal) contractor. The methodology is supported by 120 discrete cost categories, and systematic criteria for determining which costs are included (counted) in the overall cost of safety. A quality system (in compliance with ISO9000 series) was developed to support the work and ensure accuracy of data gathering. The results of the study offer some support for the business case for safety. Though they offer good support for the economics of safety as they demonstrate need for cost effectiveness. Subject to important caveats, those projects that appeared to manage safety more cost-effectively achieved the lowest overall safety cost. Nevertheless, results are significantly lower than of other published works for two main reasons; first costs due to damages with no potential to injury were not included and second only costs to main constructor were considered. Study’s results are discussed and compared with other publish works.

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Following Andersen's (1986, 1991) study of untutored anglophone learners of Spanish, aspectual features have been at the centre of hypotheses on the development of past verbal morphology in language acquisition. The Primacy of Aspect Hypothesis claims that the association of any verb category (Aktionsart) with any aspect (perfective or imperfective) constitutes the endpoint of acquisition. However, its predictions rely on the observation of a limited number of untutored learners at the early stages of their acquisition, and have yet to be confirmed in other settings. The aim of the present thesis is to evaluate the explanatory power of the PAH in respect of the acquisition of French past tenses, an aspect of the language which constitutes a serious stumbling block for foreign learners, even those at the highest levels of proficiency (Coppieters 1987). The present research applies the PAH to the production of 61 anglophone 'advanced learners' (as defined in Bartning 1997) in a tutored environment. In so doing, it tests concurrent explanations, including the influence of the input, the influence of chunking, and the hypothesis of cyclic development. Finally, it discusses the cotextual and contextual factors that still provoke what Anderson (1991) terms "non-native glitches" at the final stage, as predicted by the PAH. The first part of the thesis provides the theoretical background to the corpus analysis. It opens with a diachronic presentation of the French past tense system focusing on present areas of competition and developments that emphasize the complexity of the system to be acquired. The concepts of time, grammatical aspect and lexical aspect (Aktionsart) are introduced and discussed in the second chapter, and a distinctive formal representation of the French past tenses is offered in the third chapter. The second part of the thesis is devoted to a corpus analysis. The data gathering procedures and the choice of tasks (oral and written film narratives based on Modern Times, cloze tests and acceptability judgement tests) are described and justified in the research methodology chapter. The research design was shaped by previous studies and consequently allows comparison with these. The second chapter is devoted to the narratives analysis and the third to the grammatical tasks. This section closes with a summary of discoveries and a comparison with previous results. The conclusion addresses the initial research questions in the light of both theory and practice. It shows that the PAH fails to account for the complex phenomenon of past tense development in the acquisitional settings under study, as it adopts a local (the verb phrase) and linear (steady progression towards native usage) approach. It is thus suggested that past tense acquisition rather follows a pendular development as learners reformulate their learning hypotheses and become increasingly able to shift from local to global cues and so to integrate the influence of cotext and context in their tense choice.

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This thesis is an examination of organisational issues faced by Third Sector organisations which undertake nonviolent direct action. A case study methodology is employed and data gathered from four organisations: Earth First!; genetiX Snowball; Greenpeace; and Trident Ploughshares. The argument commences with a review of the literature which shows that little is known of the organising of nonviolent direct action. Operational definitions of 'organisation' and 'nonviolent direct action' are drawn from the literature. 'Organisation' is conceptualised using new institutionalism. 'Nonviolent direct action' is conceptualised using new social movement theory. These concepts inform the case study methodology in the choice of case, the organisations selected and the data gathering tools. Most data were gathered by semi-structured interview and participant observation. The research findings result from theory-building arising from thick descriptions of the case in the four organisations. The findings suggest that nonviolent direct action is qualitatively different from terrorism or violence. Although there is much diversity in philosophies of nonviolence, the practice of nonviolent direct action has much in common across the four organisations. The argument is that nonviolent direct action is an institution. The findings also suggest that new institutionalism is a fruitful approach to studies of these organisations. Along with nonviolent direct action, three other institutions are identified: 'rules'; consensus decision-making; and 'affinity groups'. An unanticipated finding is how the four organisations are instances of innovation. Tentative theory is developed which brings together the seemingly incompatible concepts of institutions and innovation. The theory suggests preconditions and then stages in the development of new organisational forms in new social movements: innovation. The three pre-conditions are: the existence of an institutional field; an 'institution-broker' with access to different domains; and a shared 'problem' to resolve. The three stages are: unlocking existing knowledge and practice; bridging different domains of practice or different fields to add, develop or translocate those practices; and establishing those practices within their new combinations or novel locations. Participants are able to move into and between these new organisational forms because they consist of familiar and habitual institutional behaviour.

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Purpose: Current conceptualisations of strategic flexibility and its antecedents are theory-driven, which has resulted in a lack of consensus. To summarise this domain the paper aims to develop and present an a priori conceptual model of the antecedents and outcomes of strategic flexibility. Discussion and insights into the conceptual model, and the relationships specified, are made through a novel qualitative empirical approach. The implications for further research and a framework for further theoretical development are presented. Design/methodology/approach: An exploratory qualitative research design is used applying multiple data collection techniques in a branch network of a large regional retailer in the UK. The development of strategic options and the complex relationship to strategic flexibility is investigated. Findings: The number and type of strategic options developed by managers impact on the degree of strategic flexibility and also on the ability of the firm to achieve competitive differentiation. Additionally, the type of strategic option implemented by managers is dependent on the competitive situation faced at a local level. Evidence of managers' limited perception of competition was identified based on their spatial embeddedness. Research limitations/implications: A single, in-depth case study was used. The data gathered is rich and appropriate for the exploratory approach adopted here. However, generalisability of the findings is limited. Practical implications: Strategic flexibility is rooted in the ability of front-line mangers to develop and implement strategic options; this in turn facilitates competitive differentiation. Originality/value: The research presented is unique in this domain on two accounts. First, theory is developed by presenting an a priori conceptual model, and testing through in-depth qualitative data gathering. Second, insights into strategic flexibility are presented through an examination of managerial cognition, resources and strategic option generation using cognitive mapping and laddering technique. © Emerald Group Publishing Limited.

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This paper reports findings of a two year study concerning the development and implementation of a general-purpose computer-based assessment (CBA) system at a UK University. Data gathering took place over a period of nineteen months, involving a number of formative and summative assessments. Approximately 1,000 students, drawn from undergraduate courses, were involved in the exercise. The techniques used in gathering data included questionnaires, observation, interviews and an analysis of student scores in both conventional examinations and computer-based assessments. Comparisons with conventional assessment methods suggest that the use of CBA techniques may improve the overall performance of students. However it is clear that the technique must not be seen as a "quick fix" for problems such as rising student numbers. If one accepts that current systems test only a relatively narrow range of skills, then the hasty implementation of CBA systems will result in a distorted and inaccurate view of student performance. In turn, this may serve to reduce the overall quality of courses and - ultimately - detract from the student learning experience. On the other hand, if one adopts a considered and methodical approach to computer-based assessment, positive benefits might include increased efficiency and quality, leading to improved student learning.

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Cognitive systems research involves the synthesis of ideas from natural and artificial systems in the analysis, understanding, and design of all intelligent systems. This chapter discusses the cognitive systems associated with the hippocampus (HC) of the human brain and their possible role in behaviour and neurodegenerative disease. The hippocampus (HC) is concerned with the analysis of highly abstract data derived from all sensory systems but its specific role remains controversial. Hence, there have been three major theories concerning its function, viz., the memory theory, the spatial theory, and the behavioral inhibition theory. The memory theory has its origin in the surgical destruction of the HC, which results in severe anterograde and partial retrograde amnesia. The spatial theory has its origin in the observation that neurons in the HC of animals show activity related to their location within the environment. By contrast, the behavioral inhibition theory suggests that the HC acts as a ‘comparator’, i.e., it compares current sensory events with expected or predicted events. If a set of expectations continues to be verified then no alteration of behavior occurs. If, however, a ‘mismatch’ is detected then the HC intervenes by initiating appropriate action by active inhibition of current motor programs and initiation of new data gathering. Understanding the cognitive systems of the hippocampus in humans may aid in the design of intelligent systems involved in spatial mapping, memory, and decision making. In addition, this information may lead to a greater understanding of the course of clinical dementia in the various neurodegenerative diseases in which there is significant damage to the HC.

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Purpose: In today's competitive scenario, effective supply chain management is increasingly dependent on third-party logistics (3PL) companies' capabilities and performance. The dissemination of information technology (IT) has contributed to change the supply chain role of 3PL companies and IT is considered an important element influencing the performance of modern logistics companies. Therefore, the purpose of this paper is to explore the relationship between IT and 3PLs' performance, assuming that logistics capabilities play a mediating role in this relationship. Design/methodology/approach: Empirical evidence based on a questionnaire survey conducted on a sample of logistics service companies operating in the Italian market was used to test a conceptual resource-based view (RBV) framework linking IT adoption, logistics capabilities and firm performance. Factor analysis and ordinary least square (OLS) regression analysis have been used to test hypotheses. The focus of the paper is multidisciplinary in nature; management of information systems, strategy, logistics and supply chain management approaches have been combined in the analysis. Findings: The results indicate strong relationships among data gathering technologies, transactional capabilities and firm performance, in terms of both efficiency and effectiveness. Moreover, a positive correlation between enterprise information technologies and 3PL financial performance has been found. Originality/value: The paper successfully uses the concept of logistics capabilities as mediating factor between IT adoption and firm performance. Objective measures have been proposed for IT adoption and logistics capabilities. Direct and indirect relationships among variables have been successfully tested. © Emerald Group Publishing Limited.

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Current tools for assessing risks associated with mental-health problems require assessors to make high-level judgements based on clinical experience. This paper describes how new technologies can enhance qualitative research methods to identify lower-level cues underlying these judgements, which can be collected by people without a specialist mental-health background. Content analysis of interviews with 46 multidisciplinary mental-health experts exposed the cues and their interrelationships, which were represented by a mind map using software that stores maps as XML. All 46 mind maps were integrated into a single XML knowledge structure and analysed by a Lisp program to generate quantitative information about the numbers of experts associated with each part of it. The knowledge was refined by the experts, using software developed in Flash to record their collective views within the XML itself. These views specified how the XML should be transformed by XSLT, a technology for rendering XML, which resulted in a validated hierarchical knowledge structure associating patient cues with risks. Changing knowledge elicitation requirements were accommodated by flexible transformations of XML data using XSLT, which also facilitated generation of multiple data-gathering tools suiting different assessment circumstances and levels of mental-health knowledge. © 2007 Informa UK Ltd All rights reserved.

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This article discusses the structure, anatomical connections, and functions of the hippocampus (HC) of the human brain and its significance in neuropsychology and disease. The HC is concerned with the analysis of highly abstract data derived from all sensory systems but its specific role remains controversial. Hence, there have been three major theories concerning its function, viz., the memory theory, the spatial theory, and the behavioral inhibition system (BIS) theory. The memory theory has its origin in the surgical destruction of the HC, which results in severe anterograde and partial retrograde amnesia. The spatial theory has its origin in the observation that neurons in the HC of animals show activity related to their location within the environment. By contrast, the behavioral inhibition theory suggests that the HC acts as a ‘comparator’, i.e., it compares current sensory events with expected or predicted events. If a set of expectations continues to be verified then no alteration of behavior occurs. If, however, a ‘mismatch’ is detected then the HC intervenes by initiating appropriate action by active inhibition of current motor programs and initiation of new data gathering. Understanding the anatomical connections of the hippocampus may lead to a greater understanding of memory, spatial orientation, and states of anxiety in humans. In addition, HC damage is a feature of neurodegenerative diseases such as Alzheimer’s disease (AD), dementia with Lewy bodies (DLB), Pick’s disease (PiD), and Creutzfeldt-Jakob disease (CJD) and understanding HC function may help to explain the development of clinical dementia in these disorders.