586 resultados para Power transformers, partial discharges, UHF, detectors, antennas, design methodology


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The recent explosive growth in advanced manufacturing technology (AMT) and continued development of sophisticated information technologies (IT) is expected to have a profound effect on the way we design and operate manufacturing businesses. Furthermore, the escalating capital requirements associated with these developments have significantly increased the level of risk associated with initial design, ongoing development and operation. This dissertation has examined the integration of two key sub-elements of the Computer Integrated Manufacturing (CIM) system, namely the manufacturing facility and the production control system. This research has concentrated on the interactions between production control (MRP) and an AMT based production facility. The disappointing performance of such systems has been discussed in the context of a number of potential technological and performance incompatibilities between these two elements. It was argued that the design and selection of operating policies for both is the key to successful integration. Furthermore, policy decisions are shown to play an important role in matching the performance of the total system to the demands of the marketplace. It is demonstrated that a holistic approach to policy design must be adopted if successful integration is to be achieved. It is shown that the complexity of the issues resulting from such an approach required the formulation of a structured design methodology. Such a methodology was subsequently developed and discussed. This combined a first principles approach to the behaviour of system elements with the specification of a detailed holistic model for use in the policy design environment. The methodology aimed to make full use of the `low inertia' characteristics of AMT, whilst adopting a JIT configuration of MRP and re-coupling the total system to the market demands. This dissertation discussed the application of the methodology to an industrial case study and the subsequent design of operational policies. Consequently a novel approach to production control resulted. A central feature of which was a move toward reduced manual intervention in the MRP processing and scheduling logic with increased human involvement and motivation in the management of work-flow on the shopfloor. Experimental results indicated that significant performance advantages would result from the adoption of the recommended policy set.

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Product reliability and its environmental performance have become critical elements within a product's specification and design. To obtain a high level of confidence in the reliability of the design it is customary to test the design under realistic conditions in a laboratory. The objective of the work is to examine the feasibility of designing mechanical test rigs which exhibit prescribed dynamical characteristics. The design is then attached to the rig and excitation is applied to the rig, which then transmits representative vibration levels into the product. The philosophical considerations made at the outset of the project are discussed as they form the basis for the resulting design methodologies. It is attempted to directly identify the parameters of a test rig from the spatial model derived during the system identification process. It is shown to be impossible to identify a feasible test rig design using this technique. A finite dimensional optimal design methodology is developed which identifies the parameters of a discrete spring/mass system which is dynamically similar to a point coordinate on a continuous structure. This design methodology is incorporated within another procedure which derives a structure comprising a continuous element and a discrete system. This methodology is used to obtain point coordinate similarity for two planes of motion, which is validated by experimental tests. A limitation of this approach is that it is impossible to achieve multi-coordinate similarity due to an interaction of the discrete system and the continuous element at points away from the coordinate of interest. During the work the importance of the continuous element is highlighted and a design methodology is developed for continuous structures. The design methodology is based upon distributed parameter optimal design techniques and allows an initial poor design estimate to be moved in a feasible direction towards an acceptable design solution. Cumulative damage theory is used to provide a quantitative method of assessing the quality of dynamic similarity. It is shown that the combination of modal analysis techniques and cumulative damage theory provides a feasible design synthesis methodology for representative test rigs.

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This paper is based a major research project run by a team from the Innovation, Design and Operations Management Research Unit at the Aston Business School under SERC funding. International Computers Limited (!CL), the UK's largest indigenous manufacturer of mainframe computer products, was the main industrial collaborator in the research. During the period 1985-89 an integrated production system termed the "Modular Assembly Cascade'' was introduced to the Company's mainframe assembly plant at Ashton-under-Lyne near Manchester. Using a methodology primarily based upon 'participative observation', the researchers developed a model for analysing this manufacturing system design called "DRAMA". Following a critique of the existing literature on Manufacturing Strategy, this paper will describe the basic DRAMA model and its development from an industry specific design methodology to DRAMA II, a generic model for studying organizational decision processes in the design and implementation of production systems. From this, the potential contribution of the DRAMA model to the existing knowledge on the process of manufacturing system design will be apparent.

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Purpose – The purpose of this paper is to understand the internal branding process from the perspective of service providers in Thailand. It will reveal the key internal branding mechanisms and empirically assess the relationship between internal branding and employees' brand attitudes and performance. Design/methodology/approach – A case study representing the Thai hotel industry is adopted with mixed methodologies. In-depth interviews are first carried out with 30 customer-interface employees in six major hotels in Thailand. On a census basis, a quantitative survey with 699 respondents from five major hotels in Thailand follows. Findings – Internal branding coordinating marketing with human resource management has a statistically significant impact on attitudinal and behavioural aspects of employees in their delivery of the brand promise. As employees' brand commitment do not have a statistically significant relationship with employees' brand performance, it is not regarded as a mediator in the link between internal branding and employees' brand performance. Practical implications – A number of significant managerial implications are drawn from this study, for example using both internal communication and training to influence employees' brand-supporting attitudes and behaviours. Still, it should be noted that the effect of internal branding on employee behaviours could be dependent on the extent to which it influences their brand attitudes. Originality/value – The paper provides valuable insights, from the key internal audience's perspectives, into an internal branding process. It has empirically shown the relationship between internal branding and the behavioural outcome as well as the partial meditating effects of employees' brand identification, commitment and loyalty.

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Purpose – The purpose of this paper is to investigate the extent of retail change in the UK grocery sector over the last 30 years. Design/methodology/approach – In 1980, a press article by Richard Milner and Patience Wheatcroft attempted to anticipate retail change by 1984. Taking that as a template, the paper examines how retail did, in fact, change over a much longer timescale: with some unanticipated innovations in place even by 1984. Reference is made to academic research on grocery retailing in progress at the time and which has recently been revisited. Findings – Although Milner and Wheatcroft tackled the modest task of looking ahead just four years, the content of their article is intriguingly reflective of the retail structure and systems of the UK at the time. Whilst some innovations were not anticipated, the broad themes of superstore power and market regulation still command attention 30 years on. Originality/value – Through reconsidering 30 years of retail change, the paper highlights that with time how do you shop has come to pose at least as interesting a question as where do you shop.

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Purpose – The collapse of world economic systems brought the interconnectedness between business and global events sharply into focus. As Starkey points out: “leading business schools need to overcome their fascination with a particular form of finance and economics […] to broaden their intellectual horizons […] (and to) look at the lessons of history and other disciplines”. The purpose of this paper is to provide evidence from three years of research on the Aston MBA suggesting that an emphasis on developing capabilities within a far broader, connected and reflexive business curriculum is what business students and practitioners now recognise as an essential way forward for responsible management education. Design/methodology/approach – This research paper examines the reflective accounts of 300 MBA students undertaking a transdisciplinary Business Ethics, Responsibility and Sustainability core module. Findings – As Klein argues, transdisciplinarity is simultaneously an attitude and a form of action. The student reflections provide powerful discourses of individual learning and report a range of outcomes from finding “the vocabulary or the confidence” to raise issues to acting as “change agents” in the workplace. Originality/value – As responsibility and sustainability requires learners, researchers and educators to engage with real world complexity, uncertainty and risk, conventional disciplinary study, especially within business, often proves inadequate and partial. This paper demonstrates that creative and exploratory frames need to be developed to facilitate the development of more connected knowledge – informed by multiple stakeholders, able to contribute heterogeneous skills, perspectives and expertise.

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Purpose – The purpose of this paper is to examine developments in the field of organizational change (OC) with reference to the context of India. It highlights the need to analyze this topic in the present Indian economic environment and discusses the main developments reported in the Indian literature on the same. Design/methodology/approach – Empirical evidence based on a qualitative analysis of a case study undertaken at a public-private partnership transformation at North Delhi Power Limited (NDPL) in India is presented. Findings – The findings focus on trust building and belongingness for the employees, establishing a high-performance orientation, quality improvements, and the resultant transformations at NDPL. The analysis indicates a number of ways by which NDPL sought to improve its efficiency in order to better adapt to the rapidly changing Indian business environment. Practical implications – Based on the findings, the paper identifies key messages for policy makers and change agents regarding how to transform companies in the rapidly changing business contexts of emerging markets such as India. Originality/value – The paper offers an in-depth analysis of OC practices in a large organization in India.

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Purpose - Studies the implementation of lean supply and partnership relationships in the UK food and farming industry to assess if these types of interventions are effective. Design/methodology/approach - Reviews the challenges affecting the UK supply chain for red meat. Describes the initiatives that were set up to develop a lean supply chain management approach and examines their application in the UK pig and beef industries. Assesses if these changes benefited all participants in the supply chains. Uses semi-structured interviews with key actors in each stage of the supply chain to do this, identifying the power relations within the supply chains and how these affected the outcomes for those participating in the chain. Findings - Concludes that lean initiatives were appropriate for the pig industry but were of limited value for the beef industry. Even within the pig industry, highlights that benefits were not shared equally, with producers, in particular, losing out. Lastly, points out that lean supply chain management is unlikely to be appropriate operationally and commercially in all circumstances in one industry. Argues for a differentiated policy approach and sets out a framework which enables decision makers to select industrial policy options. Research limitations/ implications - Describes the analysis and the framework developed from it. Originality/value - Assesses the effectiveness of lean supply chain management.

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Purpose: The purpose of this paper is to understand how reverse resource exchanges and resource dependencies are managed in the service supply chain (SSC) of returnable transport packaging (RTP). Design/methodology/approach: A single case study was conducted in the context of automotive logistics focusing on the RTP SSC. Data were collected through 16 interviews, primarily with managers of a logistics service provider (LSP) and document analysis of contractual agreements with key customers of the packaging service. Findings: Resource dependencies among actors in the SSC result from the importance of the RTP for the customer’s production processes, the competition among users for RTP and the negative implications of the temporary unavailability of RTP for customers and the LSP (in terms of service performance). Amongst other things, the LSP is dependent on its customers and third-party users (e.g. the customer’s suppliers) for the timely return of package resources. The role of inter-firm integration and collaboration, formal contracts as well as customers’ power and influence over third-party RTP users are stressed as key mechanisms for managing LSP’s resource dependencies. Research limitations/implications: A resource dependence theory (RDT) lens is used to analyse how reverse resource exchanges and associated resource dependencies in SSCs are managed, thus complementing the existing SSC literature emphasising the bi-directionality of resource flows. The study also extends the recent SSC literature stressing the role of contracting by empirically demonstrating how formal contracts can be mobilised to explicate resource dependencies and to specify, and regulate, reverse exchanges in the SSC. Practical implications: The research suggests that logistics providers can effectively manage their resource dependencies and regulate reverse exchanges in the SSC by deploying contractual governance mechanisms and leveraging their customers’ influence over third-party RTP users. Originality/value: The study is novel in its application of RDT, which enhances our understanding of the management of reverse exchanges and resource dependencies in SSCs.

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Purpose – Threats of extreme events, such as terrorist attacks or infrastructure breakdown, are potentially highly disruptive events for all types of organizations. This paper seeks to take a political perspective to power in strategic decision making and how this influences planning for extreme events. Design/methodology/approach – A sample of 160 informants drawn from 135 organizations, which are part of the critical national infrastructure in the UK, forms the empirical basis of the paper. Most of these organizations had publicly placed business continuity and preparedness as a strategic priority. The paper adopts a qualitative approach, coding data from focus groups. Findings – In nearly all cases there is a pre-existing dominant coalition which keeps business continuity decisions off the strategic agenda. The only exceptions to this are a handful of organizations which provide continuous production, such as some utilities, where disruption to business as usual can be readily quantified. The data reveal structural and decisional elements of the exercise of power. Structurally, the dominant coalition centralizes control by ensuring that only a few functional interests participate in decision making. Research limitations/implications – Decisional elements of power emphasize the dominance of calculative rationality where decisions are primarily made on information and arguments which can be quantified. Finally, the paper notes the recursive aspect of power relations whereby agency and structure are mutually constitutive over time. Organizational structures of control are maintained, despite the involvement of managers charged with organizational preparedness and resilience, who remain outside the dominant coalition. Originality/value – The paper constitutes a first attempt to show how planning for emergencies fits within the strategy-making process and how politically controlled this process is.

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This paper describes a design methodology to achieve optimal performance for a short-stroke single-phase tubular permanent-magnet motor which drives a reciprocating vapor compressor. The steady-state characteristic of the direct-drive linear-motor compressor system is analyzed, an analytical formula for predicting iron loss is presented, and a motor-design procedure which takes into account the effect of compressor loads under nominal operating condition is formulated. It is shown that the motor efficiency can be optimized with respect to two leading dimensional ratios. Experimental results validate the proposed design methodology. Copyright © 2010 IEEE.

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Purpose: The paper aims to design and prove the concept of micro-industry using trigeneration fuelled by biomass, for sustainable development in rural NW India. Design/methodology/approach: This is being tested at village Malunga, near Jodhpur in Rajasthan. The system components comprise burning of waste biomass for steam generation and its use for power generation, cooling system for fruit ripening and the use of steam for producing distilled water. Site was selected taking into account the local economic and social needs, biomass resources available from agricultural activities, and the presence of a NGO which is competent to facilitate running of the enterprise. The trigeneration system was designed to integrate off-the-shelf equipment for power generation using boilers of approximate total capacity 1 tonne of fuel per hour, and a back-pressure steam turbo-generator (200 kW). Cooling is provided by a vapour absorption machine (VAM). Findings: The financial analysis indicates a payback time of less than two years. Nevertheless, this is sensitive to market fluctuations and availabilities of raw materials. Originality/value: Although comparable trigeneration systems already exist in large food processing industries and in space heating and cooling applications, they have not previously been used for rural micro-industry. The small-scale (1-2 m3/h output) multiple effect distillation (3 effect plus condenser) unit has not previously been deployed at field level. © Emerald Group Publishing Limited.

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Purpose: Short product life cycle and/or mass customization necessitate reconfiguration of operational enablers of supply chain (SC) from time to time in order to harness high levels of performance. The purpose of this paper is to identify the key operational enablers under stochastic environment on which practitioner should focus while reconfiguring a SC network. Design/methodology/approach: The paper used interpretive structural modeling (ISM) approach that presents a hierarchy-based model and the mutual relationships among the enablers. The contextual relationship needed for developing structural self-interaction matrix (SSIM) among various enablers is realized by conducting experiments through simulation of a hypothetical SC network. Findings: The research identifies various operational enablers having a high driving power towards assumed performance measures. In this regard, these enablers require maximum attention and of strategic importance while reconfiguring SC. Practical implications: ISM provides a useful tool to the SC managers to strategically adopt and focus on the key enablers which have comparatively greater potential in enhancing the SC performance under given operational settings. Originality/value: The present research realizes the importance of SC flexibility under the premise of reconfiguration of the operational units in order to harness high value of SC performance. Given the resulting digraph through ISM, the decision maker can focus the key enablers for effective reconfiguration. The study is one of the first efforts that develop contextual relations among operational enablers for SSIM matrix through integration of discrete event simulation to ISM. © Emerald Group Publishing Limited.

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Purpose – On 29 January 2001, Euronext LIFFE introduced single security futures contracts on a range of global companies. The purpose of this paper is to examine the impact that the introduction of these futures contracts had on the behaviour of opening and closing UK equity returns. Design/methodology/approach – The paper models the price discovery process using the Amihud and Mendelson partial adjustment model which can be estimated using a Kalman filter. Findings – Empirical results show that during the pre-futures period both opening and closing returns under-react to new information. After the introduction of futures contracts opening returns over-react. A rise in the partial adjustment coefficient also takes place for closing returns but this is not large enough to cause over-reaction. Originality/value – This is the first study to examine the impact of a single security futures contract on the speed of spot market price discovery.

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Purpose: The purpose of this paper is to examine the effect of the quality of senior management leadership on social support and job design, whose main effects on strains, and moderating effects on work stressors-to-strains relationships were assessed. Design/methodology/approach: A survey involving distribution of questionnaires was carried out on a random sample of health care employees in acute hospital practice in the UK. The sample comprised 65,142 respondents. The work stressors tested were quantitative overload and hostile environment, whereas strains were measured through job satisfaction and turnover intentions. Structural equation modelling and moderated regression analyses were used in the analysis. Findings: Quality of senior management leadership explained 75 per cent and 94 per cent of the variance of social support and job design respectively, whereas work stressors explained 51 per cent of the variance of strains. Social support and job design predicted job satisfaction and turnover intentions, as well as moderated significantly the relationships between quantitative workload/hostility and job satisfaction/turnover intentions. Research limitations/implications: The findings are useful to management and to health employees working in acute/specialist hospitals. Further research could be done in other counties to take into account cultural differences and variations in health systems. The limitations included self-reported data and percept-percept bias due to same source data collection. Practical implications: The quality of senior management leaders in hospitals has an impact on the social environment, the support given to health employees, their job design, as well as work stressors and strains perceived. Originality/value: The study argues in favour of effective senior management leadership of hospitals, as well as ensuring adequate support structures and job design. The findings may be useful to health policy makers and human resources managers. © Emerald Group Publishing Limited.