进口经纬仪检定中亟待解决的问题

总结了作者几年来从事进口经纬仪检定工作的部分体会，就存在的几个问题进行了讨论。     

STG-BASED VERIFICATION AND TEST GENERATION

This paper presents the techniques of verification and Test Generation(TG) for sequential machines (Finite State Machines, FSMs) based on state traversing of State Transition Graph(STG). The problems of traversing, redundancy and transition fault model are identified. In order to achieve high fault coverage collapsing testing is proposed. Further, the heuristic knowledge for speeding up verification and TG are described.     

221厂核设施退役工程的竣工验收辐射检测

本文叙述２２１厂核设施退役工程的竣工验收辐射检测，内容涉及竣工验收辐射检测小组的职能和组织形式，验收检测标准，验收检测的实施及其主要结果。     

An analysis of BioHashing and its variants

As a result of the growing demand for accurate and reliable personal authentication, biometric recognition, a substitute for or complement to existing authentication technologies, has attracted considerable attention. It has recently been reported that, along with its variants, BioHashing, a new technique that combines biometric features and a tokenized (pseudo-) random number (TRN), has achieved perfect accuracy, having zero equal error rates (EER) for faces, fingerprints and palmprints. There are, however, anomalies in this approach. These are identified in this paper, in which we systematically analyze the details of the approach and conclude that the claim of having achieved a zero EER is based upon an impractical hidden assumption. We simulate the claimants’ experiments and find that it is not possible to achieve their reported performance without the hidden assumption and that, indeed, the results are worse than when using the biometric alone.     

A note on the attractor-property of infinite-state Markov chains

In the past 5 years, a series of verification algorithms has been proposed for infinite Markov chains that have a finite attractor, i.e., a set that will be visited infinitely often almost surely starting from any state. In this paper, we establish a sufficient criterion for the existence of an attractor. We show that if the states of a Markov chain can be given levels (positive integers) such that the expected next level for states at some level n>0 is less than n−Δ for some positive Δ, then the states at level 0 constitute an attractor for the chain. As an application, we obtain a direct proof that some probabilistic channel systems combining message losses with duplication and insertion errors have a finite attractor.     

分布实时系统的概率规范和证明形式化

1引言 随着数字系统变得越来越小、越来越便宜,它们用于物理过程控制和与物理过程互协作的机会将越来越多。互相协作的过程如果出现意外行为,后果将可能很严重。这种意外为不仅仅指程序和数字     

Wang laboratories' VLSI design strategy or Putting blinders on your engineers keeps your horse in the race

The article discusses the rationale used to make the decision to implement a constrained design capability for VLSI in Wang. A CAD/CAM system will be put in place that will permit product designers to achieve design and manufacturing turn-a-round times that are consistent with a product development cycle of 18 to 24 months. The functional requirements of the various subsystems are discussed as well as those for the excutive, the data base, and the audit capability. The latter capabilities are necessary to achieve a controlled constrained design environment.     

Verifying abstract data types with SNOBOL4

The presentation of an abstract data type by a series of equational axioms has become an accepted specification mechanism. Verifying the correctness of such specifications has been recognized as a problem troubling their use. A means is presented for experimenting with a directly executable version of the axioms without having to choose representations for the data structures or describe algorithms for the operations.