建模与仿真的动态V＆V技术综述

校核与验证（V＆V）技术包括非正规、静态、动态和正规四类技术，是保证建模与仿真（M＆S）的可信度的重要手段。动态V＆V技术是其中应用范围较广、数学和逻辑上比较正规的技术。它要求模型转化为应用并被执行，根据模型的执行行为来评价模型的精确性。首先简要介绍了M＆S的VV＆A和校核与验证技术的分类情况，然后论述了动态校核与验证技术并分析了各自的特点，最后介绍了在建模与仿真过程中动态V＆V技术的适用范围。对用于校核与验证的动态测试技术和统计技术作了重点介绍。     

Approximate methods for simulation and verification of numerically controlled machining programs

Algorithms for simulation and verification of Numerically Controlled (NC) machining programs are presented. Compared to NC simulation based on conventional solid modeling systems, these models are designed to give approximate results, but with a substantial decrease in computer time. The surfaces of the part are discretized into a Surface Point Set (SPS) with a point spacing dependent on cutting tool size and shape local surface curvature and the desired accuracy of the approximate simulation. The surface-surface intersection calculations of the solid modeling approach are replaced by the intersection of the surface of the tool movement envelope with straight lines emanating from the surface points. The methods are applicable to both 3 and 5 axis machining. Samples test cases are presented, and implementation and efficiency issues are discussed.     

STATE VERIFICATION FOR SYNCHRONOUS CIRCUITS

This paper presents the techniques of implicit traversing and state verification for sequential finite state machines(FSMs) based of on the state collapsing of state transition graph(STG). The problems of state designing are described. In order to achieve high state enumeration coverage, heuristic knowledge is proposed.     

Specifying Cash-Point with DisCo

We describe how the cash-point service problem of Formal Methods ’99 is specified using DisCo [Dis, JKS91]. Received January 2000 / Accepted in revised form December 2000     

Verification of Erlang Processes by Dependency Pairs

Erlang is a functional programming language developed by Ericsson Telecom, which is particularly well suited for implementing concurrent processes. In this paper we show how methods from the area of term rewriting are presently used at Ericsson. To verify properties of processes, such a property is transformed into a termination problem of a conditional term rewriting system (CTRS). Subsequently, this termination proof can be performed automatically using dependency pairs. The paper illustrates how the dependency pair technique can be applied for termination proofs of conditional TRSs. Secondly, we present three refinements of this technique, viz. narrowing, rewriting, and instantiating dependency pairs. These refinements are not only of use in the industrial applications sketched in this paper, but they are generally applicable to arbitrary (C)TRSs. Thus, in this way dependency pairs can be used to prove termination of even more (C)TRSs automatically. Received: October 6, 1999     

On coupling 1D non-isothermal heat and mass transfer in porous materials with a multizone building energy simulation model

Hygroscopic materials available in the interior of buildings such as wood, gypsum, paper etc, are able to absorb moisture if the relative humidity of the room increases and release it again if the relative humidity decreases. This moisture buffering phenomenon is often accounted for in a simplified way in Building Energy Simulation programs (BES) e.g. TRNSYS, which limits their applicability. Nevertheless several building applications require an accurate prediction of the indoor relative humidity already from the design stage.     

脉冲行波管阴极蒸发现象的验证与解决

针对某型脉冲行波管工作中出现失效的问题,通过试验分析确定失效是由阴极蒸发所致,在对阴极进行试验研究的基础上,找出了阴极的蒸发规律,通过采取改进阴极预处理工艺和适当降低阴极温度等措施,解决了阴极改盐后产生的蒸发问题;而增加行波管测试老炼时间,则提高了行波管工作稳定性和质量一致性。     

LTV model in consultant sector. Case study: mental health clinic

Since the early 1980s, customer relationship management (CRM) has been important in the new competitive business environment. Today, due to development of competitive factors in the business, the enterprise's need to create and retain effective relations with customers has been highlighted more and more. With the aim of customer scoring applications, the most profitable customers can be identified. In this paper, we categorized customers by three types of values for the clinic by using logistic regression as a data-mining technique, and calculated the customer defection and future purchase probability in a mental health clinic of the university of Tehran. Model verification and validation (using lift chart) was done and customer segmentation and analysis presented with proper marketing strategies.     

Process modeling and analysis of manufacturing supply chain networks using object-oriented Petri nets

This paper presents a systematic methodology for modeling and analysis of manufacturing supply chain business processes. The proposed approach first employs Computer Integrated Manufacturing Open System Architecture (CIMOSA) behavior rules to model the business process routing structures of manufacturing supply chain networks. Object-oriented predicate/transition nets (OPTNs) are then developed for the modular modeling and analysis of process models. Based on the structure of OPTNs, a procedure to obtain the system's P-invariants through objects’ P-invariants is suggested. From the P-invariants obtained, system structural properties such as deadlock and overflow can be analyzed. By using Petri net unfolding techniques and by extracting the process model of each object from the entire process model, the sequencing analysis for operations in supply chain processes becomes possible. Several manufacturing supply chain examples are used to illustrate the effectiveness of the proposed method.     

A dynamic specification to automatically debug and correct various divider circuits

This paper presents a formal technique to verify and debug division circuits on fixed point numbers. The proposed technique is based on a reverse-engineering mechanism of obtaining a high level model of the gate level implementation and also introducing an intermediate representation of the specification that makes equivalence checking between two models possible. The main advantage of this representation is the fact that the specification is dynamically updated according to the information obtained from the implementation. At the end, if two updated models are not equivalent, possible bugs can be localized and then corrected automatically by analyzing the difference, if possible. Experimental results show the robustness of the proposed technique in comparison with other contemporary methods in terms of the run time and also show that two orders of magnitude average speedup is obtained.