Protection Survivability Importance in Systems with Multilevel Protection

This paper considers systems that can have different states corresponding to different combinations of available elements constituting the system. Each state can be characterized by a performance rate, which is the quantitative measure of a system's ability to perform its task. Both the impact of external factors (attack) and internal causes (failures) affect system survivability, which is determined as the probability of meeting a given demand. In order to increase the system's survivability a multilevel protection is applied to its subsystems. This means that a subsystem and its inner level of protection are in turn protected by the protection of an outer level. This double‐protected subsystem has its outer protection and so forth. In such systems, the protected subsystems can be destroyed only if all of the levels of their protection are destroyed. Each level of protection can be destroyed only if all of the outer levels of protection are destroyed. In such systems, different protections play different roles in providing for the system's survivability. The evaluation of the relative influence of the protections' survivability on the survivability of the entire system provides useful information about the importance of these protections. The protection survivability importance index is introduced in order to evaluate this influence and an algorithm for evaluating the index is presented. The relevancy of protection is also considered. Illustrative examples are presented. Copyright © 2004 John Wiley & Sons, Ltd.     

全数字化保护系统考虑经济性的元件重要度分析

传统的元件重要度分析都是从纯粹的可靠性角度出发，没有考虑经济条件。文中综合考虑全数字化保护系统的制造成本以及因系统故障造成的经济损失这两方面因素，提出了考虑经济性的新型元件重要度度量模型。首先提出了基于故障率的元件成本———可靠性模型，进而得到全数字化保护系统的总成本———可靠性模型;然后定义了考虑经济性的元件重要度以及类型重要度，并推导出了计算公式;最后以典型全数字化保护系统为例，比较了考虑经济性的元件重要度与传统元件重要度的区别。结果表明，文中提出的新型元件重要度模型具有更大的动态范围，更易于区分保护元件之间的重要度，对优化系统可靠性设计更具指导意义。     

A new importance measure for risk-informed decision making

In this paper, we introduce a new importance measure, the differential importance measure (DIM), for probabilistic safety assessment (PSA). DIM responds to the need of the analyst/decision maker to get information about the importance of proposed changes that affect component properties and multiple basic events. DIM is directly applicable to both the basic events and the parameters of the PSA model. Unlike the Fussell–Vesely (FV), risk achievement worth (RAW), Birnbaum, and criticality importance measures, DIM is additive, i.e. the DIM of groups of basic events or parameters is the sum of the individual DIMs. We discuss the difference between DIM and other local sensitivity measures that are based on normalized partial derivatives. An example is used to demonstrate the evaluation of DIM at both the basic event and the parameter level. To compare the results obtained with DIM at the parameter level, an extension of the definitions of FV and RAW is necessary. We discuss possible extensions and compare the results of the three measures for a more realistic example.     

Leading us not into temptation: Momentary allurements elicit overriding goal activation.

The present research explored the nature of automatic associations formed between short-term motives (temptations) and the overriding goals with which they interfere. Five experimental studies, encompassing several self-regulatory domains, found that temptations tend to activate such higher priority goals, whereas the latter tend to inhibit the temptations. These activation patterns occurred outside of participants' conscious awareness and did not appear to tax their mental resources. Moreover, they varied as a function of subjective goal importance and were more pronounced for successful versus unsuccessful self-regulators in a given domain. Finally, priming by temptation stimuli was found not only to influence the activation of overriding goals but also to affect goal-congruent behavioral choices. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

大型核电站全厂断电事故的失效模式分析

运用故障树分析方法，对核电站全厂断电事故进行分析。建造了全厂断电事故即厂用电力系统Ａ、Ｂ两列６．６ｋＶ交流应急母线ＬＨＡ和ＬＨＢ同时失电故障树。利用ＳＥＴＳ程序及法国标准９０万千瓦压水堆核电站２００堆年运行经验反馈的可靠性数据，对全厂断电故障树作了定性、定量分析，得到了全厂断电事故的发生概率。给出了全厂断电事故的主要失效模式及发生的概率和事件的重要度。     

Importance measures in ranking piping components for risk informed in-service inspection

Risk informed in-service inspection aims at prioritising the components for inspection within the permissible risk level thereby avoiding unnecessary inspections. Various methods have been evolved for prioritisation, in which the importance measure approach has gained a wide popularity. This paper presents an importance measure that can be employed to prioritise components of any dimension, which is normally required from the point of view of carrying out a risk informed in-service inspection of nuclear power plants.     

Development of power system reliability analysis program with consideration of system operation

This paper describes a new program which analyzes the reliability of composite power systems with consideration of power system operational aspects. It uses the sequential Monte Carlo method and calculates annual risk indices for each load point. The program deals with the system problems involved in load flow, voltage, frequency, and small‐signal stability if necessary. The distinctive feature of the program is consideration of power system operation in a sequential manner, such as generation dispatch and system restoration after equipment failure. This makes possible the evaluation of both power system planning and operation from the reliability point of view. Several new methods of reducing calculation time are developed and implemented, including the concurrent LP/load flow method, which improves solvability. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 153(4): 20–31, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20138     

预序的实值函数表示

本文着重考虑预序的实函数表示问题，给出了由实函数表示的预序所拥有的几个固有性质，其中最主要的是可分离性。     

牛犊全粒面软鞋面革的制作工艺

介绍了牛犊全粒面软鞋面革的特点和制作过程中的技术操作要点。     

洁净煤技术在我国的研究进展

本文阐述了我国发展洁净煤技术的重要性和紧迫性，回顾了其最新进展，并指出了目前尚存在的问题及未来研究工作的方向。