OPTIMAL SOFTWARE RELEASE POLICY BASED ON MARKOVIAN PERFECT DEBUGGING MODEL

In this paper we consider a Markovian perfect debugging model for which the software failure is caused by two types of faults, one which is easily detected and the other which is difficult to detect. When a failure occurs, a perfect debugging is immediately performed and consequently one fault is reduced from fault contents. We also treat the debugging time as a variable to develop a new debugging model. Based on the perfect debugging model, we propose an optimal software release policy that satisfies the requirements for both software reliability and expected number of faults which are required to achieve before releasing the software. Several measures, including the distribution of first passage time to the specified number of removed faults, are also obtained using the proposed debugging model.     

GI／G／1可修排队系统的注记

在文献［１］的基础上，进一步分析了在服务台可修的ＧＩ／Ｇ／１排队系统中服务台的如下可靠性问题：１）在忙期内的失效次数；２）在时间（０，ｔ］内的平均失效次数的近似计算；３）在忙期内的失效时间和工作时间；４）在时间（０，ｔ］内平均失效时间的近似计算，并且得到一些新的可靠性参数的计算结果。     

人机工程学的发展及人机系统的可靠性

本文介绍了人机工程学(工效学)这一新兴边缘学科的研究内容、发展及现状,讨论了人-机系统的可靠性并着重讨论了人的操作可靠性,探讨了按人为差错进行可靠性分析与可靠性估计的人为差错和可靠性分析逻辑推演法(HERALD法)及系统能力方法(SC方法)。 本文的结论可供系统管理工作者及设计工作者,特别是可靠性管理及可靠性设计工作者参考。     

Optimal and Acceptable Technical Facilities Involving Risks

Economic cost-benefit optimization of technical facility requires suitable "life saving cost" and/or an appropriate acceptance criterion if human life and limb are at risk. Traditionally, acceptance criteria implicit in codes of practice, standards, or regulations for well-defined fields of application are calibrated against past and present practice. This is all but satisfying. It is unclear whether present rules are already optimal. Extrapolations into new fields of application are extremely difficult. Direct cost-benefit analysis is proposed as an alternative. Based on the recently proposed "life quality index" (LQI), a rational acceptance criterion and so-called life saving cost are derived. The classical life quality index is reviewed, modified, and imbedded in modern economics theory. The results are then applied to technical facilities. The relation between optimization and the LQI-based acceptance criterion is discussed. The relevant economics literature is reviewed with respect to discount rates applicable for long-term investments into risk reduction. They should be as low as possible according to a recent mathematical result. Modern economic growth theory decomposes the output growth rate into the rate of time preference of consumption and the rate of economical growth multiplied by the elasticity of marginal utility of consumption. It is found that the rate of time preference of consumption should be a little larger than the long-term population growth rate. The public benefit rate (output growth rate) on the other hand should be smaller than the sum of the population growth rate and the long-term growth rate of a national economy, which is around 2% for most industrial countries. Accordingly, the rate of time preference of consumption is about 1%, which is also intergenerationally acceptable from an ethical point of view. Given a certain output growth rate there is a corresponding maximum financial interest rate in order to maintain nonnegativity of the objective function at the optimum. Finally, a simple demonstration example is added.     

Covariates and Random Effects in a Gamma Process Model with Application to Degradation and Failure

The gamma process is a natural model for degradation processes in which deterioration is supposed to take place gradually over time in a sequence of tiny increments. When units or individuals are observed over time it is often apparent that they degrade at different rates, even though no differences in treatment or environment are present. Thus, in applying gamma-process models to such data, it is necessary to allow for such unexplained differences. In the present paper this is accomplished by constructing a tractable gamma-process model incorporating a random effect. The model is fitted to some data on crack growth and corresponding goodness-of-fit tests are carried out. Prediction calculations for failure times defined in terms of degradation level passages are developed and illustrated.     

The South Oaks Gambling Screen: a review with reference to Australian use

The South Oaks Gambling Screen (SOGS) is a psychometric instrument widely used internationally to assess the presence of pathological gambling. Developed by Lesieur and Blume (1987) in the United States of America (USA) as a self-rated screening instrument, it is based on DSM-III and DSM-III-R criteria. This paper describes the origins and psychometric development of the SOGS and comments critically in relation to its construct validity and cutoff scores. Reference is made to the use of the SOGS in the Australian setting, where historically gambling has been a widely accepted part of the culture, corresponding to one of the highest rates of legalised gambling and gambling expenditure in the world. An alternative approach to the development of an instrument to detect people who have problems in relation to gambling is proposed.     

Parametric Modeling for Survival with Competing Risks and Masked Failure Causes

We consider a life testing situation in which systems are subject to failure from independent competing risks. Following a failure, immediate (stage-1) procedures are used in an attempt to reach a definitive diagnosis. If these procedures fail to result in a diagnosis, this phenomenon is called masking. Stage-2 procedures, such as failure analysis or autopsy, provide definitive diagnosis for a sample of the masked cases. We show how stage-1 and stage-2 information can be combined to provide statistical inference about (a) survival functions of the individual risks, (b) the proportions of failures associated with individual risks and (c) probability, for a specified masked case, that each of the masked competing risks is responsible for the failure. Our development is based on parametric distributional assumptions and the special case for which the failure times for the competing risks have a Weibull distribution is discussed in detail.     

物流系统的可靠度及其优化研究

物流系统是一个由众多物流单元组成的大系统,它的可靠性程度对企业和社会的平稳运行有着重大的影响.本文在建立物流单元的可靠度及其度量方法基础上,研究了物流系统逻辑组成结构对系统可靠度的影响,并探讨了在有物流能力和可靠度约束的情况下,如何优化物流系统逻辑结构和物流成本的方法.     

内部控制与财务报告可靠性

高质量会计信息的基本特征应主要表现为可靠性。有效的内部控制能够合理保证财务报告的可靠性,内部控制的首要功能是维护财务报告可靠性,内部控制环境是影响财务报告的可靠性的重要因素。完善以财务报告内部控制为基础的内部控制,是新形势下会计管理工作贯彻落实科学发展观、走长期可持续发展道路的必然要求,是促进经济健康运行、规范资本市场秩序、完善现代企业制度的现实需要。     

论软件成果的法律保护与管理

软件作为高新技术的组成部分，对其采用著作权、专利权、商标权、技术秘密的综合法律保护,是促进软件成果市场化、产业化的重要措施。职务软件成果的产权的界定与合同管理是维护软件市场秩序的保障，做好软件的著作权登记可为享受国家优惠政策和申请奖励储备条件。