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The purpose of this paper is twofold: first, a case study on applying lean principles in manufacturing operations to redesign and optimize an electronic device assembly process and its impact on performance and second, introducing cardboard prototyping as a Kaizen tool offering a novel approach to testing and simulating improvement scenarios.

The study employs value stream mapping, root cause analysis, and brainstorming tools to identify root causes of poor performance, followed by deploying a Kaizen event to redesign and optimize an electronic device assembly process. Using physical models, bottlenecks and opportunities for improvement were identified by the Kaizen approach at the workstations and assembly lines, enabling the testing of various scenarios and ideas. Changes in lead times, throughput, work in process inventory and assembly performance were analyzed and documented.

Pre- and post-improvement measures are provided to demonstrate the impact of the Kaizen event on the performance of the assembly cell. The study reveals that implementing lean tools and techniques reduced costs and increased throughput by reducing assembly cycle times, manufacturing lead time, space utilization, labor overtime and work-in-process inventory requirements.

This paper adds a new dimension to applying the Kaizen methodology in manufacturing processes by introducing cardboard prototyping, which offers a novel way of testing and simulating different scenarios for improvement. The paper describes the process implementation in detail, including the techniques and data utilized to improve the process.

The purpose of this paper is to describe the application of low‐glitch current cell in a digital to analog converter (DAC) to reduce the clock‐feedthrough effect and achieve a low power consumption.

A low‐glitch current switch cell is applied in a ten‐bit two‐stage DAC which is composed of a unary cell matrix for six most significant bits and a binary weighted array for four least significant bits (LSBs). The current cell is composed of four transistors to neutralize the clock‐feedthrough effect and it enables DAC to operate in good linearity and low power consumption. The prototype DAC is being implemented in a 0.35μm complementary metal‐oxide semiconductor process. The reduction in glitch energy and power consumption has been realized by preliminary experiment and simulation.

Compared to conventional current cell, more than 15 per cent reduction of glitch energy has been obtained in this work. The DAC is estimated that differential nonlinearity is within 0.1 LSB and the maximum power consumption is 68 mW at the sampling frequency of 100 MHz.

Comparison with other conventional work indicates that the current cell proposed in this paper shows much better performance in terms of switching spike and glitch, which may come from the extra dummy transistor in cell and reduce the clock‐feedthrough effect.

Rework is an integral part of printed circuit board assembly (PCBA) manufacturing. However, the state‐of‐the‐art for PCBA rework still relies on operator activity and is therefore semi‐automatic. As a result, the quality of rework depends very much on the skill of the operator. When developing an automatic PCBA rework cell, the cell controller is an essential part which organises and controls the overall rework operation. This paper describes the software modelling of the cell controller for the PCBA rework cell which has been implemented for reworking through‐hole and surface mounted components. The software model is based on hybrid representations and rule‐based control.

Small cells, or microcells, are often seen as a way to substantially enhance the capacity of cellular networks. Previous assumptions have been that by deploying a dense layer of small cells within a macrocell, capacity can be improved by an order of magnitude or more. However, there are complexities such as the need to share frequencies between macrocell and small cells, varying patterns of users, the balance between indoor and outdoor subscribers and the different options available within 4G for balancing loading. The purpose of this study is to understand the impact these real-world constraints have on the capacity enhancements that small cells can provide.

This paper describes a model that simulates the impact of small cell deployments in macrocells in a typical 4G network.

It shows that, in some cases, small cells can actually reduce capacity, while in the best case, maximum capacity gains are less than 100 per cent.

It shows that, in some cases, small cells can actually reduce capacity contrary to perceived wisdom.

The purpose of this paper is to investigate a light-trapping structure based on Ag nanograting for amorphous silicon (a-Si) thin-film solar cell. Silver nanopillar arrays on indium tin oxide layer of the a-Si thin-film solar cells were designed.

The effects of the geometrical parameters such as nanopillar radius (R) and array period (P) were investigated by using the finite element simulation.

The optimization results show that the absorption of the solar cell with Ag nanopillar structure and anti-reflection film is enhanced up to 29.5 per cent under AM1.5 illumination in the 300- to 800-nm wavelength range compared with the reference cell. Furthermore, physical mechanisms of absorption enhancement at different wavelength range are discussed according to the electrical field amplitude distributions in the solar cells.

The research is still in progress. Further studies mainly focus on the performance of solar cells with different nanograting materials.

This study provides a feasible method for light-trapping structure based on Ag nanograting for a-Si thin-film solar cell.

This study is promising for the design of a-Si thin-film solar cells with enhanced performance.

Functional plant layouts are normally adopted in organizations that manufacture large varieties of components in low annual volumes. Attempts to improve the efficiency of these layouts have normally focused on the identification and implication of group technology cells which process a limited range of parts using flow process principles. Cell layouts provide the condition for kanban control procedures to operate, hence the benefits of just‐in‐time can be achieved in batch processing environments. However, in high variety/low volume (HV/LV) environments there is often insufficient commonality between part types to justify the formation of cells. Describes an alternative plant layout procedure (process sequence cell layout) currently being developed that allocates equipment to cells according to their position in the process routes of components. Uses a case study to illustrate how such a layout may be identified for an organization that has a typical high variety/low volume environment. Discusses the problems that need to be overcome if such systems are to be implemented and offers a description of how integrated MRP II/kanban control mechanisms can be used to control production.

This paper aims to present a three‐dimensional computational fluid dynamics (CFD) model that simulates the fluid flow, species transport and electric current flow in PEM fuel cells.

The model makes use of a general‐purpose CFD software as a basic tool incorporating fuel cell specific submodels for multi‐component species transport, electrochemical kinetics, water management and electric phase potential analysis in order to simulate various processes that occur in a PEM fuel cell.

Three dimensional results for the flow field, species transport, including waster formations, and electric current distributions are presented for two test flow configurations in the PEM fuel cell. For the two cases presented, reasonable predictions have been obtained, and this provides an insight into the effect of the flow designs to the operation of the fuel cell.

It is appreciated that the CFD modeling of fuel cells is, in general, still facing significant challenges due to the limited understanding of the complex physical and chemical processes existing within the fuel cell. The model is now under further development to improve its capabilities and undergoing further validations.

The model simulations can provide detailed information on some of the key fluid dynamics, physical and chemical/electro‐chemical processes that exist in fuel cells which are crucial for fuel cell design and optimization.

The model can be used to understand the operation of the fuel cell and provide and alternative to experimental investigations in order to improve the performance of the fuel cell.

A critical step toward an efficient contact detection algorithm is to localize the contact search to the immediate neighborhood of each particle. In particular, cell‐based algorithms are simple and require O(N) computations but become inefficient when the particles are not roughly the same diameter. The purpose of this paper is to describe a hierarchical search method with the simplicity and efficiency of the neighbor search algorithm but which is insensitive to size gradation.

In this method, particles are allocated to cells based on their location and size within a nested hierarchical cell space. Contact searches are limited to neighboring particles of equal size within their own hierarchy and occasionally with particles of larger size when no contacts are found within their own hierarchy.

The method is shown to be effective for the most severe case of highly segregated particle distributions in which a large particle is surrounded by particles of much smaller size.

This paper is of value in concentrating on particular issues in implementing the hierarchical contact detection algorithm in a parallel computing environment using message‐passing interface.

This paper aims to evaluate nine types of electrical energy generation options with regard to seven criteria. The analytic hierarchy process (AHP) was used to perform the evaluation. The TOPSIS method was used to evaluate the best generation technology.

The options that were evaluated are the hydrogen combustion turbine, the hydrogen internal combustion engine, the hydrogen fuelled phosphoric acid fuel cell, the hydrogen fuelled solid oxide fuel cell, the natural gas fuelled phosphoric acid fuel cell, the natural gas fuelled solid oxide fuel cell, the natural gas turbine, the natural gas combined cycle and the natural gas internal combustion engine. The criteria used for the evaluation are CO₂ emissions, NOX emissions, efficiency, capital cost, operation and maintenance costs, service life and produced electricity cost.

The results drawn from the analysis in technology wise are as follows: natural gas fuelled solid oxide fuel cells>natural gas combined cycle>natural gas fuelled phosphoric acid fuel cells>natural gas internal combustion engine>hydrogen fuelled solid oxide fuel cells>hydrogen internal combustion engines>hydrogen combustion turbines>hydrogen fuelled phosphoric acid fuel cells> and natural gas turbine. It shows that the natural gas fuelled solid oxide fuel cells are the best technology available among all the available technology considering the seven criteria such as service life, electricity cost, O&M costs, capital cost, NOX emissions, CO₂ emissions and efficiency of the plant.

The most dominant electricity generation technology proved to be the natural gas fuelled solid oxide fuel cells which ranked in the first place among nine alternatives. The research is helpful to evaluate the different alternatives.

The research is helpful to evaluate the different alternatives and can be extended in all the spares of technologies.

The research was the original one. Nine energy generation options were evaluated with regard to seven criteria. The energy generation options were the hydrogen combustion turbine, the hydrogen internal combustion engine, the hydrogen fuelled phosphoric acid fuel cell, the hydrogen fuelled solid oxide fuel cell, the natural gas fuelled phosphoric acid fuel cell, the natural gas fuelled solid oxide fuel cell, the natural gas turbine, the natural gas combined cycle and the natural gas internal combustion engine. The criteria used for the evaluation were efficiency, CO₂ emissions, NOX emissions, capital cost, O&M costs, electricity cost and service life.

Outlines some major features that should be incorporated into the design of cell‐based manufacturing systems. Presents these features as a series of observations which are based on experiences gained during a three‐year period covering the implementation of such a system. Presents a set of rules that are commonly applied to the design, implementation and management of cell‐based manufacturing systems. Each rule is then examined in the context of actual experience and comments are given as to the major contribution made by each rule to the successful implementation of the manufacturing system. It is hoped that the information contained in this work will be of general interest to organizations moving towards similar implementations in that it presents one view of the problems that must be met, and some suggested solutions.