Capacity requirements planning for twin Fabs of wafer fabrication

Based on the assumption of infinite capacity, a Capacity Requirements Planning System (CRPS) is developed for twin fabs of wafer fabrication. Several shared equipments exist only in one of the twin fabs linked by an Inter-Fab Material Handling System. CRPS consists of four major modules. WIP-Pulling Module pulls work-in-process (WIP) that is the closest to the end of the process route to meet the Master Production Schedule. Workload Accumulation Module then calculates the expected equipment loading in different time buckets. If WIP cannot meet the Master Production Schedule (MPS) requirement, new wafer lots need to be released. Wafer Release Time Module is used to determine the release time of new lots by evaluating their expected equipment loading at the twin fabs on various time buckets. According to the lot release time, Wafer Start Fab Module can be used to evaluate the expected loading for each of the twin fabs and determine the start fab to optimise the workload balance among these twin fabs on various days. Based on experimental design, simulation results show that CRPS can balance the equipment loading between the twin fabs with shared equipment, on various days, and across various equipments at various levels of demands.     

Set-partitioning-based heuristic for balancing and configuration of automated flexible machining line

Flexible machining lines are used in a wide range of industries due to their ability of reconfiguration to meet high variety of customer demands. A novel problem is proposed in the current research to consider automated flexible machining line (AFML) with automated machining using computer numerical control machines and automated auxiliary operations using robots. A mixed-integer programming model for the current novel problem is developed. Moreover, a novel method named set-partitioning-based heuristic (SPH) is proposed to solve this new flexible machining line balancing problem to minimise the cycle time of the line and the performance is compared with both exact algorithm and random search algorithm. A set of benchmark instances based on different size of problems against different system parameters is made. Furthermore, sensitivity analysis of the system parameter in AFML is performed to know, how the number of machines and processing time can influence the cycle time and the utilisation of AFML. Computational experiments are performed to show the performance of the proposed method SPH against other methods and the results indicate that SPH performs best among all test methods in terms of solution quality and computation on both the proposed benchmark instances.     

液晶显示屏(LCD)用三醋酸纤维素(TAC)薄膜的发展现状与前景

本文阐述了三醋酸纤维素(TAC)薄膜的一些最新发展情况。三醋酸纤维素薄膜作为片基(0.12-0.14毫米厚)应用于制作照相胶片已有多年,近年却作为偏光板的支持体(0.04-0.08毫米厚),大量应用于制作液晶显示屏LCD,代替长期以来一直应用的阴极射线管CRT,由于其不产生对人体有害的射线,因而问世后大受欢迎,更因质量迅速提高,生产技术日益成熟,成本显著下降,故其生产规模和市场发展极为迅速。     

基于LTPS制程工艺的LCD/OLED显示用玻璃基板发展综述

随着显示行业高端消费品的发展要求,LTPS成为目前显示领域炙手可热的先进技术,但是由于国外技术封锁,国内全部依赖进口,因而我们必须自主研发,提升综合竞争力。本文基于平板显示最新发展动态和研发热点,综述了高分辨率LCD/OLED显示产品所用LTPS制程工艺种类与特点,以及LTPS制程工艺对玻璃基板的理化性能要求,其中,玻璃基板耐热性、热膨胀系数、紫外透过率、弹性模量是十分关键的技术指标;论述了溢流法生产工艺和浮法生产工艺所生产的LTPS玻璃基板的优势与劣势;总结了美国和日本开发满足LTPS制程工艺的玻璃基板产品状况;讲述了我国尚未形成技术和产业突破,亟须加大对LTPS制程工艺的玻璃基板的研发投入和产业探索的现状。     

An evaluation framework for product planning using FANP,QFD and multi-choice goal programming

Technological innovation and satisfaction of customer needs are the keys to survival and success for firms, especially in global competitive high-tech industries. Since new products are usually a source of new sales and profits, the success of new product development (NPD) is essential to maintain a competitive edge and to make a decent profit in a longer term. Therefore, how to develop products that deliver the quality and functionality customers demand while generating the desired profits becomes an important task for the manufacturers. In this paper, a framework with two phases is constructed for facilitating the selection of engineering characteristics (ECs) for product design. In the first phase, quality function deployment (QFD) is incorporated with the supermatrix approach of analytic network process (ANP) and the fuzzy set theory to calculate the priorities of ECs with the consideration of the interrelationship among factors and the impreciseness and vagueness in human judgments and information. In the second phase, multi-choice goal programming model is constructed by considering the outcome from the first phase and other additional goals, such as NPD cost and manufacturability, in the attempt to select the most suitable ECs. A case study of the product design process of backlight unit (BLU) in thin film transistor liquid crystal display (TFT-LCD) industry in Taiwan is carried out to verify the practicality of the proposed framework.     

LED分区背光光扩散性能研究

液晶显示器的区域动态调光技术中,各分区背光确定后,为了保证背光降低后的亮度和显示效果,需要对液晶像素进行精确补偿。本文采用低通滤波方法模拟LED背光源在背光模组中传播时的扩散过程,得到光扩散函数模板参数,进而得知各像素的实际背光亮度,据此对液晶像素进行精确补偿。在直下式LED分区背光液晶显示系统上,通过具体图像验证了该方法的准确性。该方法采用常见的测试设备,可操作性强,精度高。经验证,背光分区为32个时,32个分区的相对误差平均值为6.41%。在动态区域调光液晶电视样机中实现了本文的扩散方法,和没有调光的电视相比,节能率达到27.06%,画面无拖尾现象。     

Disassembly process planning algorithms for end-of-life product recovery and environmentally conscious disposal

Disassembly process planning is an act of preparing detailed operation instructions for disassembling used or an end-of-life (EOL) product to recover or dispose of its constituent parts or subassemblies. The main decisions are: (a) disassembly level; (b) disassembly sequence; and (c) EOL options such as reuse, remanufacturing, recycling, incineration, landfill, etc. This study deals with the three decision variables simultaneously in the parallel disassembly environment for the objective of maximising the profit. Unlike previous studies, we consider practical constraints, i.e., reuse probability and environmental impacts of parts or subassemblies, sequence-dependent setup costs, regulation on recovery rate, and incineration capacity. To represent and solve the problem, we develop an extended AND/OR graph, and then suggest a two-phase algorithm. To show the effectiveness of the proposed algorithm, two case studies have been carried out on an automatic pencil and a telephone. Also, test results on other general product structures are reported.     

An amorphous oxide semiconductor thin-film transistor route to oxide electronics

Amorphous oxide semiconductor (AOS) thin-film transistors (TFTs) invented only one decade ago are now being commercialized for active-matrix liquid crystal display (AMLCD) backplane applications. They also appear to be well positioned for other flat-panel display applications such as active-matrix organic light-emitting diode (AMOLED) applications, electrophoretic displays, and transparent displays. The objectives of this contribution are to overview AOS materials design; assess indium gallium zinc oxide (IGZO) TFTs for AMLCD and AMOLED applications; identify several technical topics meriting future scrutiny before they can be confidently relied upon as providing a solid scientific foundation for underpinning AOS TFT technology; and briefly speculate on the future of AOS TFTs for display and non-display applications.     

A spread-sheet model for efficient production and scheduling of a manufacturing line/cell

In this paper we develop an efficient spread-sheet production planning/scheduling model for a resource-constraint production line or a manufacturing cell that produces several products but one at a time with significant changeover time and changeover cost. There are also management and physical constraints related to the operating hours, production capacity and amount of inventory allowed. The production line/cell supplies several products to customers who pull the products according to their own operating policy (working hours) that may be different from manufacture's operating hours. We also show several real-world applications and highlight the benefits and merits of the model.     

垂直通道内低温液体过冷流动沸腾传热的数值预测模型

ONB和OSV分别是过冷流动沸腾中气泡形成的却始位置及气泡开始挣脱壁面的位置,准确预测ONB及OSV的位置对于分析低温液体的流动沸腾过程具有十分重要的意义.根据传热机理的不同将低温液体过冷流动沸腾通道划分为3个区,建立了各区内沸腾传热的机理模型及各区边界的判断标准,并将新建立的理论模型纳入双流体模型实现了数值求解,根据数值计算的结果可以很方便地判断ONB及OSV的位置.建立的模型有助于从机理上实现低温液体过冷流动沸腾传热的准确预测.     

A methodological framework for the triple bottom line accounting and management of industry enterprises

Since the 1970s the purpose of the environmental protection campaign has been to try to halt the gradual deterioration of our natural habitat. Reactive and pro-active strategies were developed to incorporate environmental and social concerns into economic development beyond regulatory compliance. In this research, we present a methodology to support the new era of sustainable development for all the three areas, which implements the triple bottom line (TBL) accounting mechanism by using quantitative models. A broad TBL framework is developed to track and categorize sustainability information at the corporate level through a sustainability index system. A ‘sustainability optimization’ model incorporates environmental and social costs and values into economic activities to support the decisions of the management. This methodology can help decision makers to make ‘green’ plans, and provide strategic directions for future development.     

声振系统中高频能量流分析法研究进展

能量流分析法是预测声振系统中高频动力响应的一种有效手段,该方法引入的假设条件较少,并可基于声振系统的几何模型计算随空间变化的稳态动力响应,应用上具有很大的优点。本文首先回顾了不同结构件（包括杆、梁、板及复合结构）各种波场的能量微分方程及其理论基础的发展过程,然后,针对不同类型的声振系统耦合形式,包括结构/结构耦合,结构/流体耦合及其它耦合情况,说明了基于能量流分析的耦合问题处理方法的发展,最后,说明了计算随机激励下声振系统响应的随机能量流分析法的相关研究,以及其与经典统计能量分析法间理论关系研究的进展情况。     

GCPOF: a novel optical flow estimation algorithm leveraged by sparse ground control points

As a fundamental task in computer vision, optical flow estimation algorithms aim to establish dense pixel correspondences between image frames. This paper presents a novel optical flow estimation framework called GCPOF to handle large displacement and scale variations of scene objects, which appear frequently and pose great challenges in practice. Within the framework of GCPOF, large displacement and scale variations are captured by a new problem formulation leveraged by sparse ground control points. We present detailed theoretical derivation of the solution to the problem based on iterative reweighted least squares. Both qualitative and quantitative evaluations on synthetic and real images demonstrate that GCPOF is able to handle optical flow fields with large displacement and scale variations properly, and it runs significantly faster than relevant optical flow estimation methods.     

Integration of occupational health and safety in the facility layout planning,part II: design of the kitchen of a hospital

Facility layout design has an important effect on the performance of manufacturing systems. It intends to determine relative location of departments and machines within a plant. A good layout design must ensure that a set of criteria and objectives are met and optimised, e.g. area requirements, cost, communication and safety. The most common objective used in facility planning methods is to minimise the transportation cost. However, factors such as the plant safety, flexibility for future design changes, noise and aesthetics must be considered as well. In this paper, a case study is carried out to investigate the safety concerns in facility layout design. In this regard, a facility layout planning methodology, integrating occupational health and safety (OHS) is presented. This methodology considers transportation cost as well as safety in the facility design. By this means, OHS issues are considered at the design stage of the facility. In other words, this research demonstrates the improvements in the layout design by integrating safety aspects.     

A framework for diagnosing the delivery reliability performance of make-to-order companies

Improving performance in terms of delivery reliability is increasingly important for make-to-order (MTO) companies. Detecting improvement opportunities requires a structured diagnosis of the current performance. General problem-solving literature provides structures for diagnosis processes in general, but – depending on the performance problem to be diagnosed – a theoretical framework based on domain-specific scientific knowledge is required. This paper presents a framework for diagnosing delivery reliability performance in MTO companies. The framework consists of a diagnosis tree that structures the diagnosis process, enabling one to navigate from the achieved performance to the underlying causes related to production planning and control (PPC). A theoretical foundation, enabling the possible causes of unreliable deliveries to be structured, is based on recent scientific developments in PPC literature. Three case studies exemplify the use of the framework. The developed framework shows its particular strengths in (1) selecting the right problem areas, (2) providing the right diagnosis instruments, and (3) detecting causes related to PPC decisions. It also supports diagnosis from quantitative data available in standard ERP software packages and enables diagnosis triangulation using qualitative data from the underlying decision processes.     

A mathematical formulation and anarchic society optimisation algorithms for integrated scheduling of processing and transportation operations in a flow-shop environment

This paper addresses a permutation flow-shop scheduling problem where there are a finite number of transporters to carry jobs from each machine to its subsequent machine. The problem is first formulated as a mixed-integer linear programme, and then two anarchic society optimisation (ASO) algorithms are developed to solve large-sized instances of the problem. The numerical experience shows that the ASO algorithms are considerably effective and efficient. Finally, a sensitivity analysis is carried out to study the performance of the manufacturing system versus the transportation times and the number of transporters.     

Rapid evaluation of notch stress intensity factors using the peak stress method: Comparison of commercial finite element codes for a range of mesh patterns

The peak stress method (PSM) is an engineering, finite element (FE)‐oriented method to rapidly estimate the notch stress intensity factors by using the singular linear elastic peak stresses calculated from coarse FE analyses. The average element size adopted to generate the mesh pattern can be chosen arbitrarily within a given range. Originally, the PSM has been calibrated under pure mode I and pure mode II loadings by means of Ansys FE software. In the present contribution, a round robin between 10 Italian universities has been carried out to calibrate the PSM with 7 different commercial FE codes. To this aim, several two‐dimensional mode I and mode II problems have been analysed independently by the participants. The obtained results have been used to calibrate the PSM for given stress analysis conditions in (i) FE software, (ii) element type and element formulation, (iii) mesh pattern, and (iv) criteria for stress extrapolation and principal stress analysis at FE nodes.     

A System for Monitoring and Measuring the Volume Flow Rate of a Liquid Based on the M1821BM85A Microprocessor

It is shown that the transfer into a recording instrument of a measured volume flow rate of low-viscosity liquids in the form of a PWM-signal, and also software and hardware for carrying out the functions of monitoring and self-diagnostics and for eliminating the random component of the errors and subregulation using external crossing components in combination with the use of the M1821BM85A microprocessor, ensures the functional reliability of the monitoring and measuring system, thereby satisfying the requirements for their use in industrial and transport systems.     

Testing of numerical methods,convective schemes,algorithms for approximation of flows,and grid structures by the example of a supersonic flow in a step-shaped channel with the use of the CFX and fluent packages

An unsteady supersonic flow of a nonviscous gas with a Mach number M = 3 in a step-shaped channel has been calculated. The accuracy of the forecasts made has been analyzed on the basis of the Roe dissipation model and the advective upwind splitting method with the use of convective schemes of the second and third orders of accuracy and algorithms for approximation of flows. Triangular and polyhedral grids have been tested. The mechanism of formation of an artificial physical instability on grid structures with a local-gradient adaptation has been considered. It is shown that the existence of a singular point — a right corner — in the computational region causes a large phase change in the evolution of the flow. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 82, No. 2, pp. 326–330, March–April, 2009.