Simplicity, totality and change: a logistic viewpoint in inventory management
Abstract This paper demonstrates that even a simplified model works well when the model is revised from time to time. A new type of management problem results: easy-to-create models which cannot be validated.
A Case Study in System Dynamics Optimization
This paper presents the use of optimization as a tool for policy analysis and design in system dynamics models, and presents a demonstration of its use on the ‘project model’ developed by G. P. Richardson and A. L. Pugh III in their book Introduction to System Dynamics Modelling with DYNAMO. The use of optimization to design parameters, table functions and new model structure is shown to produce a very significantly improved performance for this model compared to conventional approaches.
Ultrathin Wafer Pre-Assembly and Assembly Process Technologies: A Review
Ultrathin silicon wafer technology is reviewed in terms of the semiconductor applications, critical challenges, and wafer pre-assembly and assembly process technologies and their underlying mechanisms. Mechanical backgrinding has been the standard process for wafer thinning in the semiconductor industry owing to its low cost and productivity. As the thickness requirement of wafers is reduced to below 100 μm, many challenges are being faced due to wafer/die bow, mechanical strength, wafer handling, total thickness variation (TTV), dicing, and packaging assembly. Various ultrathin wafer processing and assembly technologies have been developed to address these challenges. These include wafer carrier systems to handle ultrathin wafers; backgrinding subsurface damage and surface roughness reduction, and post-grinding treatment to increase wafer/die strength; improved wafer carrier flatness and backgrinding auto-TTV control to improve TTV; wafer dicing technologies to reduce die sidewall damage to increase die strength; and assembly methods for die pick-up, die transfer, die attachment, and wire bonding. Where applicable, current process issues and limitations, and future work needed are highlighted.