An Algorithm for Timing Verification of Systems Constrained by Min–max Inequalities

To determine the maximum separation between events for nonrepetitive systems with max and linear constraints, there are the “iterative tightening from above” (ITA) approach and the “iterative tightening from below” (ITB) approach. Since such systems can be formulated as systems constrained by min–max inequalities, this paper gives an algorithm named MMIMaxSep for solving min–max inequalities. The algorithm is a generalization and a mathematically elegant reformulation of Yen et al.’s MaxSeparation algorithm which uses the ITB approach. Our numerical experiments indicate that MMIMaxSep is very efficient. Moreover, MMIMaxSep has a unique advantage of being able to directly handle tree-represented min–max functions, and its complexity is closely related to the complexity of computing cycle time of min–max functions.

Improving Speech Recognition Accuracy for Small Vocabulary Applications in Adverse Environments

The problem of improving the accuracy of small vocabulary isolated word speaker dependent speech recognition under adverse conditions such as factory environments is considered. A new approach to solving this problem, by using Output Probability Distributions (OPDs), is presented. OPDs improve the system performance by modelling inter-word relationships, something that a standard maximum likelihood (ML) technique fails to do. The system was tested using the TI46 database, corrupted with the NOISEX-92 database, as well as in a real-world factory environment, and achieved good results.     

Using an induction prover for verifying arithmetic circuits

We show that existing theorem proving technology can be used effectively for mechanically verifying a family of arithmetic circuits. A theorem prover implementing: (i) a decision procedure for quantifier-free Presburger arithmetic with uninterpreted function symbols; (ii) conditional rewriting; and (iii) heuristics for carefully selecting induction schemes from terminating recursive function definitions; and (iv) well integrated with backtracking, can automatically verify number-theoretic properties of parameterized and generic adders, multipliers and division circuits. This is illustrated using our theorem prover Rewrite Rule Laboratory (RRL). To our knowledge, this is the first such demonstration of the capabilities of a theorem prover mechanizing induction. The above features of RRL are briefly discussed using illustrations from the verification of adder, multiplier and division circuits. Extensions to the prover likely to make it even more effective for hardware verification are discussed. Furthermore, it is believed that these results are scalable, and the proposed approach is likely to be effective for other arithmetic circuits as well.     

基于FPGA的AVS视频解码芯片验证平台设计

针对AVS视频解码芯片仿真和验证的要求,提出了基于FPGA的验证平台框架。该验证平台主要用于对AVS解码芯片进行硬件模块的验证,从而为整个视频解码芯片的开发提供可靠的依据。该平台基于Nios II软核处理器,可使软件模块和硬件模块在一个平台下真正实现软硬件协同工作。基于该平台实现了多个硬件模块和AVS视频解码芯片的验证,其结果证明了该验证平台的正确性和可靠性。     

Livelocks in parallel programs

This paper is the second of a two-part series exploring the subtle correctness criterion of the absence of livelocks in parallel programs. In this paper we are concerned with the issue of proving this correctness criterion. It is shown that livelocks are not preserved by reduction, implying that reduction cannot be used directly in proving the absence of livelocks. Two applicable proof techniques are also presented. One is based on the notion of establishing sufficient conditions for livelock-freedom; the other is an extension of the well-founded set method for proving termination in sequential programs.     

Ontology-based empirical knowledge verification for professional virtual community

A professional virtual community provides an interactive platform for enterprise experts to create and share their empirical knowledge cooperatively, and the platform contains a tremendous amount of hidden empirical knowledge that knowledge experts have preserved in the discussion process. Therefore, enterprise knowledge management highly prioritises how to verify the empirical knowledge effectively before archiving it into enterprise knowledge repository for reuse. This work develops a novel scheme of ontology-based empirical knowledge verification for professional virtual community to assist domain experts in a professional virtual community to verify the logics of empirical knowledge, thus ensuring the quality of empirical knowledge and providing accurate knowledge decision support for knowledge workers. In particular, this work has the following objectives: propose an empirical knowledge verification model for a professional virtual community, design an ontology-based empirical knowledge verification process, develop techniques related to the ontology-based empirical knowledge verification and implement an ontology-based empirical knowledge verification mechanism with an illustrative example of securities trading. Results of this study facilitate efforts within the professional virtual community to verify empirical knowledge in order to provide knowledge workers with logic-correct empirical knowledge for decision support.     

探析俄罗斯出口认证发展趋势

本文简明扼要的介绍了俄罗斯GOST认证的含义,结合实例剖析GOST认证体系发展趋势。此外,从汽车安全以及环保两方面就GOST认证与我国的强制性认证做了比较,分析了两方面试验的关注点以及试验中暴露出来的整车问题。     

基于工作过程的戴维南定理学习之探讨

电工基础是一门理论性实践性都很强的专业基础课程,这门课程所涉及的定理,可以说在电子类专业中算是较多的,是多年来学生普遍反映较难学的一门课程,文章以戴维南定理为例,就如何讲好戴维南定理提出了自己的看法,由模拟仿真到定理得出再到后期实验验证,由感性认识到理性认识,再到实践升华,按照这样的思路,层层递近,把抽象的定理变成直观的,学生能触手可及的东西。这种基于工作过程的授课模式适合大多数基础薄弱的高职生,经多年的实践验证,学生真正做到了学有所获,学有所得。     

地震概查在快速找煤中的应用效果

地震概查一般在煤田预测的基础上进行,主要是通过稀疏的地震勘探线控制预测含煤区域,并对工作区有无进一步工作价值作出评价。以内黄隆起区进行地震概查工作为例,论述了地震概查在快速找煤中的应用及效果,在本次概查成果的基础上结合区内以往钻探资料,在较短的时间内实现了豫北地区找煤工作的重大突破,为河南提供了4处大型煤炭开发后备基地。同时,在工作过程中引入了“三边”工作制度及专家监审机制,保证了地震概查在快速找煤中的应用效果。