Showing papers on "Process modeling published in 1982"
TL;DR: The use of process computers and microcomputers permits the application of methods which result in an earlier detection of process faults than is possible by conventional limit and trend checks as mentioned in this paper...
316 citations
01 Jan 1982
TL;DR: A detailed equation oriented model of a process for the production of ethylene oxide and ethylene glycol is developed to fill this void and GRG codes are found to provide the only practical approach to large scale design optimization.
Abstract: Meaningful evaluation of the utility and performance of available nonlinear programming techniques for engineering design optimization requires the availability of realistic design models. Such models have been notably lacking in the process design area. In this paper a detailed equation oriented model of a process for the production of ethylene oxide and ethylene glycol is developed to fill this void. The model involves a large number of variables and equality constraints which are by equation sequencing reduced to 22 independent and equality constraints which are by equation sequencing reduced to 22 independent variables, nineteen constraints, as well as bounds. The salient features of such models, their usefulness and limitations are presented. The applicability of available NLP algorithms and inherent difficulties in their application are discussed. Test results are reported with representative codes. GRG codes are found to provide the only practical approach to large scale design optimization.
15 citations
TL;DR: This representation gives an overview about different aspects of modeling and simulation techniques applied in these tools in the design of IC's as an aid to optimize devices, reduce design time and costs.
5 citations
TL;DR: In this article, the reliability of prediction in modeling in chemical engineering has been reviewed and the relation to fundamentals, the role of mathematics and computing, the place of dimensional analysis and the connection between micro-and macro-scale events.
3 citations
Journal Article•
2 citations
TL;DR: In this paper, the authors describe a hierarchical level of abstraction for the simulation of field effect transistor (FET) devices beyond the micron dimension, where geometry effects and high field transport on active devices are considered.
Abstract: Phys!cal understanding of submicron device phenomena is key to the efficient use of these structures in circuit applications and to the invention of new device structures and concepts. Modeling activities are categorized in hierarchical levels of abstraction which extends the concept of hierarchical system simulation down to the fundamental levels of process modeling. Major emphasis in field-effect transistor (FET) modeling beyond the micron dimension is on the incorporation of geometry effects and high field transport on active devices. As geometry sizes shrink, the effects of both carrier types become important even in unipolar devices. For very large-scale integrated (VLSI) circuits at these geometries modeling of parasitic devices like interconnections and isolation are important in determining circuit operation and performance.
2 citations
TL;DR: CHEMOS has been developed as a highly interactive process modeling program for use with undergraduate design projects and with undergraduate and graduate thesis projects and has routines to perform optimization calculation and can produce graphical output.
01 Jan 1982
TL;DR: In this paper, the current state-of-the-art in complete process modeling is summarized, and the important aspects of both technology modeling and computer simulation which make it possible to numerically simulate multiple diffused species, as well as redistribution effects associated with moving boundaries in oxidation and epitaxy, are discussed.
Abstract: This article summarizes the current state-of-the-art in complete process modeling. Important aspects of both technology modeling and computer simulation which make it possible to numerically simulate multiple diffused species -- arsenic-boron and phosphorus-boron -- as well as redistribution effects associated with moving boundaries in oxidation and epitaxy will be discussed.
TL;DR: In this paper, a parametric model of the industrial forehearth, developed using a forced perturbation signal is presented and its suitability for improved process control is discussed.