Measures of information for continuous observations

Certain measures of information between a state process and an observation process and between a state process and an estimate of the state process are considered. The observations are assumed to have sample paths which are almost surely continuous. The calculus of martingales and probability measure transformations are used to determine representations of the observation process and the state estimate on different probability spaces obtained by a change in the sub-o-algebra and/or the probability measure. The Radon-Nikodym derivatives required to calculate the information theoretic quantities are obtained from these representations.     

A PCA-Based PCM Data Analyzing Method for Diagnosing Process Failures

In an IC process line, after a process is finished, the process control module or monitor (PCM) is tested and the data are examined so that the status of the process quality is known. In the case of a process failure, the root cause of the failure must be analyzed, and relevant actions must be taken to correct it. In this paper, we describe a novel way of diagnosing process failures. First, the tested PCM parameters, which are correlated to each other, are analyzed and transformed to a new set of independent parameters using principal component analysis (PCA). In the second step, the most important eigenvectors from PCA calculation are identified, and the causes of the process failures can therefore be extracted. Furthermore, using the PCA eigenvectors as a coordinate base, the state space of a process can be constructed. As a result, the process states from different lots of wafers can be compared; thus, it is possible to trace the IC processes, or even to predict a possible process failure, before it happens     

Process Platform Planning for Variety Coordination From Design to Production in Mass Customization Manufacturing

The key challenge of implementing mass customization manufacturing lies in the variety dilemma exhibited by frequent design changes and recurrent process variations. A holistic view of variety handling gives rise to the importance of variety coordination from design to production. This paper proposes a concept of process platform for coordinating product and process variety. Fundamental issues of process platforms are studied regarding generic product and process structures, generic planning, and generic variety representation. Variety handlers and associated states are introduced to model the meta-structure inherent in variety coordination. A set of modeling formalisms are developed to provide a powerful syntactic model to support rigorous analysis and manipulation of process platforms, while facilitating the application of semantics to support process platform enactment and detailed observations from a number of perspectives involving customers, design and production. Also reported is a case study of mass customization manufacturing of vibration motors for mobile phone products. The managerial implications of process platform planning are further discussed     

Automated analysis structures for BiCMOS process simulation, development, and verification

This paper presents a system of BiCMOS process step simulation, development, and verification using automatically generated physical test structures. During process development, detailed unit process step deliverables are compiled in a document called the process technology table (PTT). These targets are initially set by equipment capabilities, product needs, and process simulations, but every PTT entry must be ultimately verified on silicon. Therefore, the process development engineers require a method of specifying, simulating, and analyzing a large variety of process test structures. A computer-aided design system to do this has been developed. The particulars of its use during the integration of a 0.35-/spl mu/m BiCMOS process flow are presented. Details about a novel cross-sectional structure labeling and identification scheme are also presented.     

Statistical methods for the estimation of process variation effects on circuit operation

In this paper, a technology computer-aided design (TCAD) driven method for accurate prediction of the performance spread of integrated circuits due to process variations is presented. The methodology starts with the development of the nominal process recipe and process simulators are calibrated to an existing process to obtain nominal device characteristics. After determining nominal process parameters, their variations are introduced followed by screening experiments to determine the relative effects of given process variations on the input-output delay and the average power dissipation in a circuit. Response surface models (RSMs) are then generated based on critical process factors identified. Process parameter optimization is performed using these RSM models to tune the mean circuit performance and to improve the yield. This methodology is demonstrated on a 33-stage ring oscillator manufactured with a CMOS design flow. The proposed methodology maps the process domain to design space, and plays a key role in design for manufacturability (DFM) to quantify direct impact of the process variations on circuits.     

Run-by-run estimation-based control of meniscus coating

This paper describes the application of process control techniques to the meniscus coating process. Meniscus coating may be used to deposit polymers used in integrated circuits and electronics packages. Three control schemes are presented and each employs Kalman filtering to identify process coefficients. The three schemes differ according to the process model and amount of process information that is available. The dominating process parameters are applicator speed and material viscosity which affect the output of film thickness. The first scheme addresses the case where the least amount of information is known; viscosity is not measured. Identification and control is applied to a meniscus coater that does not have hardware to sense viscosity. In the second control scheme, viscosity sensors are used. However, limitations of the process model and the nature of the process produce controller lag in the presence of a shift in the process. This lag is undesirable in a manufacturing setting, therefore the third scheme is introduced which improves upon the second by reducing lag. The third scheme employs curves fitted to a history of process data to reinitialize the coefficient estimates when there is a shift in the process     

Process simplification in DRAM manufacturing

DRAM manufacturers are driving the quest for integration friendly, simplified, and statistically-controlled process development. In the DRAM field, strong emphasis must be placed on “process simplification” as a means of staying cost effective and competitive. In order to examine process architecture and process integration, both at the module and system levels, it is emphasized that using correct statistical methods in conjunction with advanced technology is important. For simplified process development and integration, many aspects of the new process assessment are data driven. Also, it is critical to understand the source of variation in the process, obtain process stability, and assess the process capability relative to specifications of manufacturability and functionality. Statistical process control techniques are a requirement for interpreting the results of process capability studies, as will be discussed in this paper. In this paper, we have emphasized that both statistical methods and technological innovation are required for process optimization. We have investigated several examples that illustrate the methodology followed for the development of statistically controlled, production-worthy processes. The process improvement strategy is described both for gate stack and the DRAM cell. The focus of the results described here is both in the context of enhancing process capability for existing processes and evaluating alternate process options that can be accomplished through the use of advanced process technology     

A framework for process change

Forces such as technology change and increased competition provide opportunities and challenges that drive a firm to continuously evaluate and modify its resource capabilities. As a consequence, a firm's process change strategy is of paramount importance for sustained manufacturing success. However, fundamental elements of process change strategy are not well understood. Long term performance benefits associated with potential process change alternatives are often unclear. Moreover, uncertainty exists regarding the actual benefits that may be attained from various types of process change. Critical issues impacting the proper implementation of process change are frequently underestimated or largely ignored. Therefore, despite the improved performance sought, process change often leads to lower productivity, excessive equipment downtime, and deterioration in quality. As the authors review the relevant empirical and normative literature, a framework emerges that characterizes the salient features of a firm's process change strategy. The underlying dynamics of process change are explored and strategies are discussed to reduce the short-term disruption and enhance the long-term gain. In particular, the authors demonstrate the importance of creating and applying knowledge to improve the outcome of process change. They describe managerial actions that can be taken to reduce various sources of uncertainty associated with process change. Moreover, they identify key contributions as well as limitations of the existing normative literature on process change. Insights from the empirical literature are given that both support elements of the existing normative models and provide direction for future normative research. Thus, the authors seek to aid practicing managers and researchers alike to better understand the full scope and implications of process change.     

无铅回流焊接的实施

电子产品无铅化,这是人类保护环境的举措,在实施过程中会遇到很多问题,如材料、工艺、检查等,作为我们电子行业无铅工艺的推进者,是要从实际中总结经验教训,把不知的通过试验变成知道的,把不成熟的过程工艺试验变为成熟工艺,把生产过程中出现的不良现象逐渐减少,优化工艺过程,把无铅工艺成熟化.在这里通过无铅生产实施过程中总结出来的一些看法,特别是无铅回流焊接实施,谈谈考虑的因素,作为无铅回流焊接实施者的参考.     

扩展自相似过程的表示及其性质

本文对于文献[5]中所提出的扩展自相似过程，给出了这一过程的一般表示形式，并基于此对扩展自相似过程进行了详细的解释，给出了扩展自相似过程压缩函数的基本性质，对于深入理解扩展自相似过程的行为机理、建立数据和过程的扩展自相似模型及有关扩展自相似过程的研究与应用有重要意义。最后给出了有关自相似过程判断的实验结果。     

On the Slepian process of a random Gaussian trigonometricpolynomial

It is proved that the Slepian process of a stationary trigonometric polynomial with Gaussian coefficients has a Karhunen-Loeve expansion consisting of a finite number of terms, and that each eigenfunction is itself a finite trigonometric polynomial. Upper bounds for the error which results when replacing the Slepian process corresponding to a general Gaussian stationary process by the Slepian process corresponding to its finite trigonometric approximation are obtained. A numerical example is given and the results are used to estimate by simulation the distribution of the excursion time above a level of a particular Gaussian stationary process     

一种软件开发新方法--过程模式

目前,软件开发的复杂性不断提高,过程模式为减少软件开发过程中的复杂性提供了一个很好的工具,为给定的任务提供了一个结构化的方法.文中首先阐明了过程、模式,以及过程模式的定义,接着描述了过程模式的3种类型:任务过程模式,步骤过程模式,阶段过程模式.过程模式是实践验证的软件开发方法,软件开发机构可用它来提高软件的质量、可维护性和可扩展性.     

Gallium-arsenide process evaluation based on a RISC microprocessorexample

The authors evaluate the features of a gallium-arsenide E/D MESFET process in which a 32-b RISC microprocessor was implemented. The design methodology and architecture of this prototype CPU are described. The performance sensitivities of the microprocessor and other large circuit blocks to different process parameters are analyzed, and recommendations for future process features, circuit approaches, and layout styles are made. These recommendations are reflected in the design of a second microprocessor using a more advanced process that achieves much higher density and performance     

Learning method for identification of process dynamics

The dynamic behaviour of some parts of a process can be relatively easily used as part of a process model (the initial process model). Small perturbations are applied to the process input, and the initial process model can be updated by a learning procedure to give an updated process model, which should accurately match the process.     

Characterization of parasitic transistors to evaluate CMOS processuniformity

The design and fabrication of several families of parasitic transistors available in a standard CMOS process are discussed and their application to process control examined. These transistors are characterized and their extracted parameters correlated with those obtained from CMOS devices. From these correlations it is concluded that parasitic transistors are very sensitive to changes in the process that influence the performance of MOS transistors. As a result parasitic transistors can be used in conjunction with standard MOS devices and test structures to provide a more complete picture of CMOS process variation     

Process mapping: one of three, new, special quality tools for management, quality and all other professionals

What is process mapping? Is it identifying, documentation, analyzing and developing an improved process. To use process mapping methodology, a completely new, different thought pattern occurs when the process is focused upon. Management's obsession with the outcomes must be abandoned and replaced with a focus on the process. A process map is used to understand your business and improve the performance of your processes. Why improve and manage processes? Processes produce an organization's products and/or services. Processes are critical to seizing and maintaining a competitive advantage. Processes are the vehicles for exceeding customer expectations and achieving organizational goals. The performance of individuals is only as good as the process will allow it to be. Processes, especially cross-functional business practices, are usually not documented, not standardized, not measured, not systematically and continually improved and not managed by the micro-process doer or owner. A process map is a visual aid for picturing work processes which shows how inputs and tasks are linked. A process map prompts new thinking about how work is done. It highlights major steps taken to produce an output, who performs the steps, and where these (major) problems consistently occur. Process mapping alerts one to areas in which a change in processes will have the greatest impact on improving quality. An excellent analogy of a process map is a `road map'. Teams become an important aspect of developing and using process maps. Very often, several functions, working separately and independently, are involved in a successful process.     

Dataflow process networks

We review a model of computation used in industrial practice in signal processing software environments and experimentally and other contexts. We give this model the name “dataflow process networks,” and study its formal properties as well as its utility as a basis for programming language design. Variants of this model are used in commercial visual programming systems such as SPW from the Alta Group of Cadence (formerly Comdisco Systems), COSSAP from Synopsys (formerly Cadis), the DSP Station from Mentor Graphics, and Hypersignal from Hyperception. They are also used in research software such as Khoros from the University of New Mexico and Ptolemy from the University of California at Berkeley, among many others. Dataflow process networks are shown to be a special case of Kahn process networks, a model of computation where a number of concurrent processes communicate through unidirectional FIFO channels, where writes to the channel are nonblocking, and reads are blocking. In dataflow process networks, each process consists of repeated “firings” of a dataflow “actor.” An actor defines a (often functional) quantum of computation. By dividing processes into actor firings, the considerable overhead of context switching incurred in most implementations of Kahn process networks is avoided. We relate dataflow process networks to other dataflow models, including those used in dataflow machines, such as static dataflow and the tagged-token model. We also relate dataflow process networks to functional languages such as Haskell, and show that modern language concepts such as higher-order functions and polymorphism can be used effectively in dataflow process networks. A number of programming examples using a visual syntax are given     

Orthogonal functionals of the Poisson process

In analogy to the orthogonal functionals of the Brownian-motion process developed by Wiener, ltô, and others, a theory of the orthogonal functionals of the Poisson process is presented making use of the concept of multivariate orthogonal polynomials. Following a brief discussion of Charlier polynomials of a single variable, multivariate Charlier polynomials are introduced. An explicit representation as well as an orthogonality property are given. A multiple stochastic integral of a multivariate function with respect to the Poisson process, called the multiple Poisson-Wiener integral, is defined using the multivariate Charlier polynomials. A multiple Poisson-Wiener integral, which gives a polynomial functional of the Poisson process, is orthogonal to any other of different degree. Several explicit forms are given for the sake of application. It is shown that any nonlinear functional of the Poisson process with finite variance can be developed in terms of these orthogonal functionals, corresponding to the Cameron-Martin theorem in the case of the Brownian-motion process. Finally, some possible applications to nonlinear problems associated with the Poisson process are briefly discussed.     

An extended Suzuki model for land mobile satellite channels and itsstatistical properties

This paper deals with the statistical characterization of a stochastic process which is a product of a Rice and lognormal process. Thereby, we consider the more general case where the two Gaussian noise processes describing the Rice process are correlated. The resulting process are named as extended Suzuki process, which can be used as a suitable statistical model for describing the fading behavior of large classes of frequency nonselective land mobile satellite channels. In particular, the statistical properties (e.g., probability density function (pdf) of amplitude and phase, level-crossing rate, and average duration of fades) of the Rice process with cross-correlated components as well as of the proposed extended Suzuki process are investigated. Moreover, all statistical model parameters are optimized numerically to fit the cumulative distribution function and the level-crossing rate of the underlying analytical model to measured data collected in different environments. Finally, an efficient simulation model is presented which is in excellent conformity with the proposed analytical model     

基于开发流程的测试流程管理

通过分析传统测试流程的缺点,根据软件开发流程各个阶段的特点,提出了建立基于开发流程的测试流程,通过对开发流程中各阶段文档和产品的评审和测试,形成详尽的测试文档,为提高软件开发效率和保障软件质量,提供了一套行之有效的管理方案。