25 resultados para lifecycle

em Aston University Research Archive


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Biomass is projected to account for approximately half of the new energy production required to achieve the 2020 primary energy target in the UK. Combined heat and power (CHP) bioenergy systems are not only a highly efficient method of energy conversion, at smaller-scales a significant proportion of the heat produced can be effectively utilised for hot water, space heating or industrial heating purposes. However, there are many barriers to project development and this has greatly inhibited deployment in the UK. Project viability is highly subjective to changes in policy, regulation, the finance market and the low cost incumbent; a high carbon centralised energy system. Unidentified or unmitigated barriers occurring during the project lifecycle may not only negatively impact on the project but could ultimately lead to project failure. The research develops a decision support system (DSS) for small-scale (500 kWe to 10 MWe) biomass combustion CHP project development and risk management in the early stages of a potential project’s lifecycle. By supporting developers in the early stages of project development with financial, scheduling and risk management analysis, the research aims to reduce the barriers identified and streamline decision-making. A fuzzy methodology is also applied throughout the developed DSS to support developers in handling the uncertain or approximate information often held at the early stages of the project lifecycle. The DSS is applied to a case study of a recently failed (2011) small-scale biomass CHP project to demonstrate its applicability and benefits. The application highlights that the proposed development within the case study was not viable. Moreover, further analysis of the possible barriers with the DSS confirmed that some possible modifications to be project could have improved this, such as a possible change of feedstock to a waste or residue, addressing the unnecessary land lease cost or by increasing heat utilisation onsite. This analysis is further supported by a practitioner evaluation survey that confirms the research contribution and objectives are achieved.

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The verification and validation of engineering designs are of primary importance as they directly influence production performance and ultimately define product functionality and customer perception. Research in aspects of verification and validation is widely spread ranging from tools employed during the digital design phase, to methods deployed for prototype verification and validation. This paper reviews the standard definitions of verification and validation in the context of engineering design and progresses to provide a coherent analysis and classification of these activities from preliminary design, to design in the digital domain and the physical verification and validation of products and processes. The scope of the paper includes aspects of system design and demonstrates how complex products are validated in the context of their lifecycle. Industrial requirements are highlighted and research trends and priorities identified. © 2010 CIRP.

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AKT is a major research project applying a variety of technologies to knowledge management. Knowledge is a dynamic, ubiquitous resource, which is to be found equally in an expert's head, under terabytes of data, or explicitly stated in manuals. AKT will extend knowledge management technologies to exploit the potential of the semantic web, covering the use of knowledge over its entire lifecycle, from acquisition to maintenance and deletion. In this paper we discuss how HLT will be used in AKT and how the use of HLT will affect different areas of KM, such as knowledge acquisition, retrieval and publishing.

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Singapore's electronics manufacturers are facing many questions. In the computer hard-drive industry, where the problem of obsolescence is common and where a product's lifecycle may be only six months, manufacturers are anxious to know what the next order-winning criteria will be. Since low labour costs are no longer a key factor, many organisations are developing their competencies in research and development, sales and marketing, logistics and supply chain management in order to maintain competitiveness. This paper illustrates how Seagate has envisaged a climate of cooperation and collaboration to better serve its customers in the areas of technology, cost and delivery. The paper is based on observations and findings following a longitudinal case study approach at the Seagate Storage Product Group (SPG) in Singapore. The seven-stage implementation framework adopted by Seagate in their SCM project is discussed, together with the process of how Seagate has created a paradigm shift towards a new culture of teamwork-based collaboration.

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Customer Base Analysis is perhaps the first stage of analysis in customer value, aiming to predict purchase frequency and customer lifecycle. An important part of the customer purchase frequency and its retention has to do with the service upgrade. Many models have tried to predict purchase frequency as well as upgrading. The comparison of these models seems important to provide academics with a picture of the current situation. The purpose of this research is to evaluate how models can predict service upgrade among a customer database of an online DVD rental company and suggest an alternative based on data mining techniques and data on historical transactions.

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Polymers are subject to oxidation throughout their lifecycle. Antioxidants are generally incorporated in polymers to inhibit or minimise oxidative degradation. Hindered phenolic antioxidants are important stabilisers for polyolefins. However, hindered phenols undergo chemical transformations while performing their antioxidant function during processing and fabrication. In addition, antioxidants are subject to loss from polymers during processing, or subsequently in-service. Migration of antioxidants is a major concern in applications involving polymers in direct contact with food and human environment. This concern is compounded by the realisation that very little is known about the nature and the migration behaviour of antioxidant transformation products. In this work, the antioxidant role of the biological antioxidant -tocopherol (Vitamin E) , which is structurally similar to many synthetic hindered phenols, is investigated in low density polyethylene (LDPE) and polypropylene (PP). The melt stabilising effectiveness of -tocopherol (Toc) was found to be very high, higher than that of commercial hindered phenol antioxidants, such as Irganox 1076 (Irg 1076) and Irganox 1010 (Irg 1010), after multiple extrusions, especially at very low concentrations. The high antioxidant activity of Toc was shown to be due, at least in part, to the formation of transformation products during processing. The main products formed are stereoisomers of dimers and trimers, as well as aldehydes and a quinone - the relative concentration of each was shown to depend on the processing severity, the initial antioxidant concentration and oxygen availability. These transformation products are shown to impart better, similar or lower melt stability to the polymer than the parent antioxidant. The nature of the products formed from Toc during processing was compared with those formed during processing of Irg 1076 and Irg 1010 with LDPE and a mechanism for the melt stabilisation of Toc was proposed and compared with the stabilisation mechanisms of the synthetic antioxidants Irg 1076 and Irg 1010.

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Jackson System Development (JSD) is an operational software development method which addresses most of the software lifecycle either directly or by providing a framework into which more specialised techniques can fit. The method has two major phases: first an abstract specification is derived that is in principle executable; second the specification is implemented using a variety of transformations. The object oriented paradigm is based on data abstraction and encapsulation coupled to an inheritance architecture that is able to support software reuse. Its claims of improved programmer productivity and easier program maintenance make it an important technology to be considered for building complex software systems. The mapping of JSD specifications into procedural languages typified by Cobol, Ada, etc., involves techniques such as inversion and state vector separation to produce executable systems of acceptable performance. However, at present, no strategy exists to map JSD specifications into object oriented languages. The aim of this research is to investigate the relationship between JSD and the object oriented paradigm, and to identify and implement transformations capable of mapping JSD specifications into an object oriented language typified by Smalltalk-80. The direction which the transformational strategy follows is one whereby the concurrency of a specification is removed. Two approaches implementing inversion - an architectural transformation resulting in a simulated coroutine mechanism being generated - are described in detail. The first approach directly realises inversions by manipulating Smalltalk-80 system contexts. This is possible in Smalltalk-80 because contexts are first class objects and are accessible to the user like any other system object. However, problems associated with this approach are expounded. The second approach realises coroutine-like behaviour in a structure called a `followmap'. A followmap is the results of a transformation on a JSD process in which a collection of followsets is generated. Each followset represents all possible state transitions a process can undergo from the current state of the process. Followsets, together with exploitation of the class/instance mechanism for implementing state vector separation, form the basis for mapping JSD specifications into Smalltalk-80. A tool, which is also built in Smalltalk-80, supports these derived transformations and enables a user to generate Smalltalk-80 prototypes of JSD specifications.

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The current rate of global biodiversity loss led many governments to sign the international agreement ‘Halting Biodiversity Loss by 2010 and beyond’ in 2001. The UK government was one of these and has a number of methods to tackle this, such as: commissioning specific technical guidance and supporting the UK Biodiversity Acton Plan (BAP) targets. However, by far the most effective influence the government has upon current biodiversity levels is through the town planning system. This is due to the control it has over all phases of a new development scheme’s lifecycle.There is an increasing myriad of regulations, policies and legislation, which deal with biodiversity protection and enhancement across the hierarchical spectrum: from the global and European level, down to regional and local levels. With these drivers in place, coupled with the promotion of benefits and incentives, increasing biodiversity value ought to be an achievable goal on most, if not all development sites. However, in the professional world, this is not the case due to a number of obstructions. Many of these tend to be ‘process’ barriers, which are particularly prevalent with ‘urban’ and ‘major’ development schemes, and is where the focus of this research paper lies.The paper summarises and discusses the results of a questionnaire survey, regarding obstacles to maximising biodiversity enhancements on major urban development schemes. The questionnaire was completed by Local Government Ecologists in England. The paper additionally refers to insights from previous action research, specialist interviews, and case studies, to reveal the key process obstacles.Solutions to these obstacles are then alluded to and recommendations are made within the discussion.

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This research examines the evolution of interorganizational relationships in a franchising context. Using U-curve theory, we develop three hypotheses and contrast them with traditional lifecycle theory. Three groups of constructs are affected by lifecycle: cooperation variables, dependence variables, and relationship variables. Four distinct stages emerge, with highest levels of variables in the honeymoon stage, lower levels in routine and crossroad stages, and increasing levels in the stabilization stage. Franchisors should strive for “stability on high levels” before operational realities influence the franchisees. Franchisees’ intermediate lifecycle phases are most critical for the system, since opportunistic behavior and switching are most likely.

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This chapter looks at how the current global economic crisis has impacted upon the global automotive industry from an operations and supply chain perspective. It presents an empirical and theoretical background to help long and short term planning for organisations experiencing adverse trading conditions. The empirical research study (conducted between 2004-07 primarily in Germany) revealed that organisations are able to make short term improvements to performance by reducing costs and making process and structural improvements, but in the long term the deeper rooted causes of the industry can in part only be dealt with by improving interfirm R&D collaborations based upon competencies rather than cost related issues. A new approach known as Collaborative Enterprise Governance is presented which supports the design and management of competitive sustainable enterprises; it consists of a data capture tool, a body of knowledge and a dynamic reference grid to show how many part-to-part company relationships can exist simultaneously to make up productprocess focused enterprises. Examples from the German automotive industry are given, impact upon the overall product development lifecycle and the implications for organisational strategists are discussed. © 2010 Nova Science Publishers, Inc. All rights reserved.

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Despite years of effort in building organisational taxonomies, the potential of ontologies to support knowledge management in complex technical domains is under-exploited. The authors of this chapter present an approach to using rich domain ontologies to support sense-making tasks associated with resolving mechanical issues. Using Semantic Web technologies, the authors have built a framework and a suite of tools which support the whole semantic knowledge lifecycle. These are presented by describing the process of issue resolution for a simulated investigation concerning failure of bicycle brakes. Foci of the work have included ensuring that semantic tasks fit in with users’ everyday tasks, to achieve user acceptability and support the flexibility required by communities of practice with differing local sub-domains, tasks, and terminology.

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Controlled polymerization of 2-chloro-1,3-butadiene using reversible addition–fragmentation chain transfer (RAFT) polymerization has been demonstrated for the first time. 2-Chloro-1,3-butadiene, more commonly known as chloroprene, has significant industrial relevance as a crosslinked rubber, with uses ranging from adhesives to integral automotive components. However, problems surrounding the inherent toxicity of the lifecycle of the thiourea-vulcanized rubber have led to the need for control over the synthesis of poly(2-chloro-1,3-butadiene). To this end, four chain transfer agents in two different solvents have been trialed and the kinetics are discussed. 2-Cyano-2-propylbenzodithioate (CPD) is shown to polymerize 2-chloro-1,3-butadiene in THF, using AIBN as an initiator, with complete control over the target molecular weight, producing polymers with low polydispersities (Mw/Mn < 1.25 in all cases).

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Purpose: The purpose of this paper is to investigate the use of high-value manufacturing (HVM) concepts in Scottish SMEs and define how they are being used to gain competitive advantage. Design/methodology/approach: Cross-sectional research carried out using a large-scale survey of 435 SMEs and semi-structured interviews of a subset of 50 SMEs. Findings: Findings indicate that HVM is not a homogeneous state but an umbrella term for a number of operational models adopted by manufacturers that are progressively moving from simple price-based production; companies must, as a foundation, be operationally excellent in all lifecycle phases before extending their capability by offering a more comprehensive service; HVM is not a static state but a journey that differs in nature for each manufacturer depending on the nature of its market and customer. Research limitations/implications: The approach to theory must be more integrated combining aspects of marketing, strategic and operational theory. Research must be carried out using the supply chain, rather than the firm, as the unit of analysis. Practical implications: Manufacturing efficiency has now become an order qualifier and competitive advantage should now be sought through the integration of design, production and service activities from strategic levels down to operational levels across all the functions of a business which link seamlessly to customer and supplier activities. Originality/value: This paper contains insights into Scottish SMEs and their practice of HVM; defines the activity that makes up HVM at an operational as opposed to an economic or strategic level; proposes a model that characterises the stages of HVM that SMEs transition through. © Emerald Group Publishing Limited.

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Polyolefins, which normally undergo high temperature manufacturing and fabrication operations, are susceptible to oxidation during each stage of their lifecycle. Stabilisers and antioxidants are used to inhibit the oxidative damage that is ultimately responsible for loss of physical properties, embrittlement and premature failure. Environmental awareness and health and safety considerations have spurred intense searches for new approaches to procure improved, safe, and more efficient antioxidants and stabiliser systems for polymers. Current activities have concentrated on two approaches: the first advocates the use of biological (naturally occurring) antioxidants, and the second relies on the use of reactive antioxidants that are chemically attached onto the polymer backbone for greater permanence and safety. Stabilisation of polyolefins through the use of vitamin E and some reactive, non-migratory antioxidants is the subject matter of this chapter.

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Construction customers are persistently seeking to achieve sustainability and maximize value as sustainability has become a major consideration in the construction industry. In particular, it is essential to refurbish a whole house to achieve the sustainability agenda of 80% CO2 reduction by 2050 as the housing sector accounts for 28% of the total UK CO2 emission. However, whole house refurbishment seems to be challenging due to the highly fragmented nature of construction practice, which makes the integration of diverse information throughout the project lifecycle difficult. Consequently, Building Information Modeling (BIM) is becoming increasingly difficult to ignore in order to manage construction projects in a collaborative manner, although the current uptake of the housing sector is low at 25%. This research aims to investigate homeowners’ decision making factors for housing refurbishment projects and to provide a valuable dataset as an essential input to BIM for such projects. One-hundred and twelve homeowners and 39 construction professionals involved in UK housing refurbishment were surveyed. It was revealed that homeowners value initial cost more while construction professionals value thermal performance. The results supported that homeowners and professionals both considered the first priority to be roof refurbishment. This research revealed that BIM requires a proper BIM dataset and objects for housing refurbishment.