RESEARCH DIRECTIONS IN ELECTRONICS MANUFACTURING

The Workshop on Electronics Manufacturing Research was held in College Station, Texas, on February 24-26, 1992. It focused on the Industrial Engineering/Operations Research/Management Science disciplines and their capabilities in modeling, analysis, and manufacturing technology. The primary goal was to identify the critical research needs in electronics manufacturing and assembly that can be addressed by these disciplines and the means of accomplishing them.

Sponsors included the Production Systems Program of the National Science Foundation (NSF), three organizations at Texas A&M University (the Department of Industrial Engineering, the Texas Engineering Experiment Station, and the Institute of Manufacturing Systems), and SEMATECH. In addition. Ford Electronics, IBM, and INTEL each sponsored one representative.

Individuals recognized for their research accomplishments in the electronics industry were invited to participate. Representing ongoing programs across the United States and Mexico in industry, government, and academia, the group identified fertile research directions as a guide for the research community and sponsoring agencies. Interacting tracks dealt with semiconductor manufacturing and circuit card (and higher level) assembly. This paper documents the important research themes identified relative to three topic areas: integrating systems, models for design and operation of production/assembly systems, and assurance sciences. It also summarizes a lively discussion which sought ways to improve the effectiveness of university/industry partnering relationships. This paper includes essential recommendations that resulted from the Workshop, but the interested reader can obtain a somewhat more detailed Final Report from Dr. Wilbert E. Wilhelm, the Principal Investigator for the Workshop project.     

THROUGHPUT MAXIMIZATION IN FLEXIBLE MANUFACTURING SYSTEMS

Maximizing the throughput (or revenue generation) rate has become one of die most important criteria in die design and management of Flexible Manufacturing Systems (FMSs). This paper develops dynamic part-allocation policies for FMSs having finite storage capacity at each work station. Maximizing the throughput rate means that the resulting queueing network model has a state-dependent arrival process; therefore, product-form solutions do not hold. Consequently, several alternative modeling approaches are described and formulated for deriving die optimal part-routing policies. One of these optimal policies is based on a new initiated-suspension part-routing strategy. This strategy results in a reduced load on the material handling system while increasing die expected throughput (or revenue generation) rates of the manufacturing work stations. We also propose several efficient closed-loop heuristic policies that exploit die response structure of die optimal policies. These heuristic policies are of practical significance because they are extremely easy to compute and to implement, while die resulting FMS performance is nearly optimal.     

INTEGRATION OF TECHNIQUES IN PROCESS DEVELOPMENT

Recently, there has been renewed interest in the philosophy of investigation, and in particular, in its essentially inerative/adaptive nature. The iterative rather than the “one-shot” concept for experimentation has profound implications for the way we approach statistical inference, the use of data analysis, and experimental design. With this in mind it seems appropriate to make the following article more generally available. This article originally appeared more than 30 years ago in the transactions of the 11th Annual Convention of the American Society for Quality Control.     

DECISION SUPPORT IN RURAL TELECOMMUNICATION NETWORK PLANNING

In this work we present the relevant features and methodological approaches of a DSS (Decision Support System) for dynamic planning of rural telecommunication networks. We outline the complexities and difficulties of the formulation and of the planning process. A relevant feature of the model is the attempt to integrate AI techniques and specialized heuristics (using mathematical programming algorithms for particular sub-problems), aiming at obtaining solutions of better quality. The structure of the DSS is presented and justified as well as the main procedures of the model, regarded from the point of view of the decision environment.     

ROBOT TASK SCHEDULING IN A FLEXIBLE MANUFACTURING CELL

Effective sequencing and scheduling of the material handling system can have a major impact on the productivity of the manufacturing system. This is especially true in the case where material handling times are on par with machine processing times. In a dynamic, real-time environment, the optimal solution of this scheduling problem may be computationally infeasible.

In this paper, we develop a branch and bound approach which is coupled with quick, effective bounds to optimize the movement of a robot which serves the material handling requirements within a manufacturing cell. Computational results are given which explore the tradeoff between computation time and deviation from optimal for different scenarios.     

HEURISTIC APPROACHES FOR LOADING PROBLEMS IN FLEXIBLE MANUFACTURING SYSTEMS

Flexible manufacturing systems (FMSs) are able to process a wide variety of operations, but the specific mix of operations that can be performed at any point in time depends upon the combination of tools loaded onto the machines. The machines have tool magazines with finite capacities. We consider the problem of assigning operations and their associated tools to machines (or groups of machines) to maximize the throughput for a specified steady-state mix of orders. Since this objective is difficult to deal with directly, we use an intermediate objective of meeting workload targets for each machine group as closely as possible. A certain form of this intermediate objective has been shown to correlate highly with the original objective.

Since it is computationally intractable to find optimal solutions for problems with more than 20 operations, fast heuristic algorithms are developed. These algorithms are adapted from multi-dimensional bin-packing algorithms. Computational results are reported.     

压蒸条件下热碱溶液中白云石的稳定性1．反应的热力学基础

通过计算热碱溶液中白云石与岩石中的杂质成份及水泥水化产物间可能发生的化学反应的平衡条件来评估压蒸条件下热碱溶液中白云石的稳定性。热碱溶液中白云石与石英、微斜长石、滑石、硬石膏、氢氧化钙或ＯＨ－有可能发生化学反应，白云石与白云母、绿泥石或水硅钙石之间的反应在热力学上是不可能的。     

PRODUCTION SCHEDULING IN A FLEXIBLE MANUFACTURING SYSTEM WITH SETUPS

A model is presented for the planning and scheduling of production batches in a flexible manufacturing system environment in which setup costs and times are nonnegligible and alternate routings are possible. The formulation is an integer program with a multicommodity flow network structure. A heuristic procedure based on price-directive decompostion using column generation is used to obtain solutions. Numerical experimentation is performed to assess die quality of the heuristic versus optimal solutions, and to determine the impact of routing flexibility on total cost, inventory levels, bottlenecks, capacity utilization, throughput time, number of setups and split lots. Important cost-benefit trade-off implications are shown for the design of flexible manufacturing systems.     

DECISION MAKING IN A GAME FOR REPLENISHMENT OF PERISHABLES

In the exercise described in this paper, players assume the role of retailers of a perishable commodity which is subject to variable demand. Each player makes a decision about the re-order quantity at the beginning of a cycle and penalties are imposed for leftovers or runouts at the end of the cycle. The performance of players can be compared with the optimal rule of a theoretical model, in which the demand distribution is assumed to be stationary. Experiments were conducted to study whether players improved their performance with time, whether managers with industrial experience performed better than players with little or no experience, whether the theoretical model was helpful in improving performance and whether the pattern of decisions was affected by the generated demand data.     

OTHER INCOME PATTERNS AND STOCHASTIC CONSIDERATIONS IN ECONOMIC DECISION MAKING

The purpose of this paper is two fold: first to provide a method for evaluating projects which have an income pattern describable by a polynomial function of time, and to provide a means for evaluating projects which exhibit a yearly growth or decline in earnings while maintaining the ability to account for the time pattern of earnings, and second to bring forth an assessment technique which will reflect the possibility of attaining various levels of income for each of the periods of interest. Methods utilized in developing the various models are based on the concept of dynamic return.

The future and present worths of a project are calculated for the case in which the earnings follow a pattern of the form given by either Ct^m or C(l — t)^m. Two types of growth patterns, geometric, in which earnings increase or decline by a fixed percentage each year, and arithmetic, in which earnings increase or decrease by a fixed amount each year, are analyzed. Finally, an income model based on the binomial distribution is developed for evaluating projects which could have two income levels, each having an associated probability. Upper and lower confidence limits for the present and future worths of the project are calculated. Extensions are noted which will permit the inclusion of any of a number of levels of profit for each year of the project.     

超疏水表面的制备技术及其应用

就超疏水膜的制备技术及其应用的最新成果进行了概括.利用含氟材料极低的表面能,将掺杂技术、气相沉积、溶液凝胶、等离子刻蚀、等离子沉积、碳纳米管阵列排布等技术有机结合,可获得适宜的表面粗糙度和微观构造,能显著提高材料的超疏水性能.其独特超疏水的性质,在国防、工农业生产和日常生活中有着广泛的应用前景.     

地震工程中动力方程求解的逐步积分方法

许多数值逐步积分方法在地震动力问题分析中得到了应用，但对于每一问题选用适当的逐步积分方法非常必要。本文介绍了地震工程中应用的一些时域数值逐步积分方法，分析与阐述了它们的基本特性（计算稳定性，精度，高频能耗性，幅值超越性），并在此基础上就合理地选用数值逐步积分方法问题给出了建议。     

移动分布荷载下层状粘弹性体系的动力响应分析

以粘弹性Burgers模型模拟沥青面层,建立了路面结构层状粘弹性体系模型。利用积分变换和传递矩阵法,并结合广义Duhamel积分,推导出了移动分布荷载作用下层状粘弹性体系动力响应的解析解。利用样条插值函数开发了计算奇异、振荡函数多重无穷积分的计算程序,完成了动力响应从波数-频率域到时间-空间域的转化,与已有文献数据和有限元结果进行了比较,显示出了较好的一致性。结合算例分析了移动分布荷载作用下层状粘弹性体系的振动特性。结果表明,粘弹性解大于弹性解,Burgers模型能反映沥青路面变形的滞后现象,层状粘弹性体系的垂向位移随行车速度和Burgers模型材料参数的增加而减小。     

A QUALITY CONFIDENCE PROCEDURE FOR GDSS APPLICATION IN MULTICRITERIA DECISION MAKING

This paper introduces a procedure for improving the quality of group decision making. Emphasis is placed on the identification of outliers and on the establishment of confidence limits in group decision making. Participants in group decision making whose opinions fall outside the group's tolerance level are further studied to annex the source of this variation.

The study presents 30 stakeholders with the task of deciding whether or not to adopt a new manufacturing technology (computer integrated manufacturing). The goal in either choice is the improvement of the total productivity of the organization. The decision made by this group is based on a pairwise comparison of seven manufacturing dimensions. Priorities for these criteria are generated using me analytic hierarchy process (AHP). These priorities are analyzed to identify potential outliers. Procedures on how to manage these outliers in order to improve the quality of decisions arrived at by the group are provided.