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This paper proposes a modified nonlinear viscoelastic Bilston model (Bilston et al., 2001, Biorheol., 38, pp. 335-345). for the modeling of brain tissue constitutive properties. The modified model can be readily implemented in a commercial explicit finite element (FE) code, PamCrash. Critical parameters of the model have been determined through a series of rheological tests on porcine brain tissue samples and the time-temperature superposition (TTS) principle has been used to extend the frequency to a high region. Simulations by using PamCrash are compared with the test results. Through the use of the TTS principle, the mechanical and rheological behavior at high frequencies up to [10.sup.4] rad/s may be obtained. This is important because the properties of the brain tissue at high frequencies and impact rates are especially relevant to studies of traumatic head injury. The averaged dynamic modulus ranges from 130 Pa to 1500 Pa and loss modulus ranges from 35 Pa to 800 Pa in the frequency regime studied (0.01 rad/s to 3700 rad/s). The errors between theoretical predictions and averaged relaxation test results are within 20% for strains up to 20%. The FEM simulation results are in good agreement with experimental results. The proposed model will be especially useful for application to FE analysis of the head under impact loads. More realistic analysis of head injury can be carried out by incorporating the nonlinear viscoelastic constitutive law for brain tissue into a commercial FE code. [DOI: 10.1115/1.2264393] Keywords: traumatic brain injury, rheological test, material properties, finite element simulation, impact biomechanics

It cannot be denied that environmental consciousness is becoming important. Ironically, legislation is probably the most satisfactory driver for pushing manufacturers to take environmental concerns into design considerations. In fact, the European Union introduced a new law (directive 2005/32/EC) for regulating the environmental consequences of all energy-using products (EuPs) in August 2007, the scope of which covers all products that rely on energy sources in any form for operation. Design alternatives are required in the product development stage so that environmental concerns can be considered as a decision parameter. In complying with the directive, life-cycle assessment (LCA) is a useful tool to draw conclusions and to compare the performance of alternatives. In this connection, a case study is carried out to assess the environmental impact of a personal electronic product through LCA, subject to the scope of the stated directive. The objectives of this paper are threefold: (i) to report the case in relation to the directive; (ii) to summarise the results of the LCA accordingly; and (iii) to suggest a new conceptual design and to compare the LCA of this new design with the original design. [ABSTRACT FROM PUBLISHER]

Reverse logistics has become more and more important to the automobile industry, owing to various reasons including unavoidable product recalls, legislative policy regarding environmental and sustainable issues, etc. In fact, the need for recovery of returned vehicles has been receiving more attention than ever before due to growing environmental concerns. Ironically, not many automobile manufacturers have a satisfactory reverse logistics system for recovering and reusing returned vehicles. This is partly because the effort devoted to this area is not very systematically investigated. In this connection, this paper aims at investigating the reverse logistics activities of the automobile industry, and to provide a framework for those activities. Firstly, the drivers for reverse logistics in this industry are revisited. Key components which are valuable and feasible for reuse or remanufacture are then identified. Based on this investigation, a framework of reverse logistics for the automobile industry is proposed. This is based on several evaluation factors (i.e. value of reversed products, legislation perspective and cost issues). Implementation issues and managerial implications are also summarised. [ABSTRACT FROM PUBLISHER]

The performance of a Flexible Manufacturing System (FMS) largely depends on how the control system can control the flow of entities in the system. The control system takes control decisions based on the information provided as an input to the decision-making process. Therefore, it is important that the decision-making process and information systems operate in a synchronised manner with respect to the FMS characteristics. This can also be referred to as a Decision-Information-Synchronisation (DIS) operating zone implemented in the control system. To study the DIS in the present research, three types of visibility for decision-makers in FMS shop-floor control have been identified: (1) no local visibility, (2) physical local visibility and (3) physical and information local visibility of decision-maker/operator. These alternative visibilities and automation levels of decision and information system provide the hybrid environments of FMSs control. The current paper presents an approach to identify the DIS operating zone of FMS with suitable visibility of decision-maker and automation level. Simulation results show that under non-real-time control (low automation level in decision and information system) with physical local visibility, the FMS system performs comparable with the real-time control (high automation level in decision and information system) when routing flexibility levels are presented. Under the current global competitive environment, this study helps industrial managers determine a suitable level of visibility and automation in planning an FMS control system in order to obtain the desired performance at the lower cost. [ABSTRACT FROM AUTHOR]

As supply chains continue to replace individual companies as the management arena for value-adding from the beginning of the twenty first century, understanding the supply chain management practices in a globalisation context becomes increasingly important. The Supply Chain Operations Reference (SCOR) Model, which was developed by the experts and practitioners of the Supply Chain Council, is a major framework for supply chain planning that features supply chain management practices and business process reengineering. Despite being an integrative guide with many merits, it only provides a 'top-down' approach that requires the comparative analyses of post- and pro-performance indices as a basis of business process modification. This study discusses the limitations of current SCOR analysis and provides a mapping technique—Causes/Effects, the SCOR Standard, and Mutual Solution (CESM)—for gap mapping, problem prioritisation, and business process modification in a supply chain setting. As such, it is one of the early empirical studies combining BPR and SCM disciplines. The research results can facilitate the implementation processes of multinational supply chain projects by identifying the gaps and linking them to the channel entities. [ABSTRACT FROM AUTHOR]

We investigated the effects of free space charges on hysteresis-loop measurement of compositionally graded ferroelectrics and found that they are quite likely to be responsible for the “polarization offsets” observed in experiments. Taking into account conduction by those free space charges, or time-dependent space-charge-limited conduction, our computer simulation of compositionally graded lead zirconate titanate, which is placed in the Sawyer–Tower circuit and driven by an alternating applied voltage, produced shifting of measured hysteresis loops where the shift magnitudes are comparable with published experimental data. It also produced the key features as observed in experiments: The “offsets:” (a) have a monotonous increase with electric-field amplitude, (b) change in direction when the composition gradient is inverted, and (c) develop like the typical charging-up of a capacitor. All these results suggest that time-dependent space-charge-limited conduction is a possible origin of the polarization offsets observed in compositionally graded ferroelectrics. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Byline: Felix T.S. Chan, H.K. Chan, Henry C.W. Lau, Ralph W.L. Ip Since the last decade, effective supply chain management has been regarded as the source of cost reduction, improvement of services, and gaining competitive advantages. Some researchers have already investigated several methods that could be employed to manage supply chains as well. However, not all companies can afford to implement all these methods properly. It is because these methods may not be suitable to every company or industry, and it would take a great effort (i.e. money) in doing so. This paper aims to highlight some critical success factors for managing global supply chains, which are obtained by analysis of case studies and related survey results in the literature. The focus of this paper would be put on the vendors' management side. It includes how to select vendors in lean and mass productions, the skills of developing and maintaining relationship by using product development and strategic suppliers' alliance. Suggestions will be given based on the evaluation of the cases and reported literature.

Byline: H.K. Chan, Felix T.S. Chan Radio Frequency Identification (RFID) is not a new technology and has been introduced for military applications for a long time. Nevertheless, it has been recognised as a device that may soon change the mode of operations throughout the supply chain. There is no question that the technology will reduce labour and improve accuracy in inventory management by improving inventory visibility. However, a review of recent research and the development of RFID technology in supply chain related applications indicated that deployment of the technology are restricted to the mandates of some giant players in the industries. It is still unclear that how return on investment of RFID-based projects could be justified. This paper aims to present a review of the technology and some recent development of RFID in relation to supply chain applications. Future research direction is then suggested.

Byline: Felix T.S. Chan, H.K. Chan, H.J. Qi Manufacturers have been exploring innovative strategies to achieve and sustain their competitive advantages by facing a new era of intensive global competition. Such a strategy is Supply Chain Management (SCM), which has gained a tremendous amount of attention from both researchers and practitioners since the last decade. Well-designed supply chain systems can substantially improve efficiency and product quality, and eventually enhance customer satisfaction and profitability. There is still a lack of integration between Performance Measurement Systems (PMSs) and practical requirements for supply chains. Performance Measurement (PM) is a vital task in SCM because it can help to monitor the progress, identify weak areas, enhance motivation, and strengthen accountability. The methodologies of business PM have been evolving for decades; numerous theories and models of PMS, ranging form design to implementation, have been proposed. However, the vast majority of PM models have concentrated on single business organisations or on partial performance areas. A commonly accepted PMS for supply chains is hardly available. This paper sets out to discuss and review recent development of PMSs, in particular those in relation to SCM, and to suggest further research direction in supply chain PMSs.