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451.
电力系统在线安全分析偶然事故排序方法的改进   总被引:5,自引:1,他引:5  
考虑到系统元件发生故障的不确定性,把对偶然事故排序中通常采用的系统行为指标(performance index)同系统状态概率相结合,形成偶然事故对系统影响的期望值,以此对偶然事故进行排序,使得对偶然事故的选择更具有合理性。分别对IEEE-RTS24母线和73母线系统进行试算,说明考虑事故发生概率对偶发事故进行排序选择是很有必要的。  相似文献   
452.
In web browsers, a variety of anti-phishing tools and technologies are available to assist users to identify phishing attempts and potentially harmful pages. Such anti-phishing tools and technologies provide Internet users with essential information, such as warnings of spoofed pages. To determine how well users are able to recognise and identify phishing web pages with anti-phishing tools, we designed and conducted usability tests for two types of phishing-detection applications: blacklist-based and whitelist-based anti-phishing toolbars. The research results mainly indicate no significant performance differences between the application types. We also observed that, in many web browsing cases, a significant amount of useful and practical information for users is absent, such as information explaining professional web page security certificates. Such certificates are crucial in ensuring user privacy and protection. We also found other deficiencies in web identities in web pages and web browsers that present challenges to the design of anti-phishing toolbars. These challenges will require more professional, illustrative, instructional, and reliable information for users to facilitate user verification of the authenticity of web pages and their content.  相似文献   
453.
人工神经网络和短时仿真结合的暂态安全评估事故筛选方法   总被引:13,自引:5,他引:13  
结合人工神经网络(ANN)和短时数字仿真提出一个用于在线暂态安全评估的事故筛选方法,将3层BP网络作为模式分类器,用来建立稳定评估结果和所选特征量之间的映射关系,在故障切除时刻终止的短时数字仿真被用来生成ANN的输入量,每个ANN处理一个特定的事故状态,使用一个半监督学习算法,ANN可产生一个能够指示相对稳定度的连续分布的暂态稳定指标,基于这个连续分布的稳定指标,设置一个相对保守的分类门槛值,避免  相似文献   
454.
Contingency management (CM) interventions usually reinforce submission of drug-negative specimens, but they can also reinforce adherence with goal-related activities. This study compared the efficacy of the 2 approaches. Substance-abusing outpatients (N = 131) were randomly assigned to 1 of 3 12-week treatments: standard treatment (ST), ST with CM for submitting negative urine toxicology screens, or ST with CM for completing goal-related activities. CM patients remained in treatment longer and achieved more abstinence than ST patients, but the CM condition that reinforced submission of negative samples resulted in better outcomes than the CM condition that reinforced goal-related activities. Abstinence at 6- and 9-month follow-ups did not differ by group, but longest duration of abstinence achieved during treatment was associated with abstinence posttreatment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
455.
Our case study explored a Local Resilience Forum's (LRF) civil contingency response to COVID-19 in the United Kingdom. We undertook 19 semistructured ethnographic longitudinal interviews, between March 25, 2020 and February 17, 2021, with a Director of a Civil Contingencies Unit and a Chief Fire Officer who both played key roles within their LRF. Within these interviews, we focused on their strategic level decision-making and how their relationship with national government impacted on local processes and outcomes. Using a form of grounded theory, our data describe the chronological evolution of an increasingly effective localized approach toward outbreak control and a growing resilience in dealing with concurrent emergency incidents. However, we also highlight how national government organizations imposed central control on aspects of the response in ways that undermined or misaligned with local preparedness. Thus, during emergencies, central governments can undermine the principle of subsidiarity and damage the ways in which LRFs can help scaffold local resilience. Our work contributes to the theoretical understanding of the social psychological factors that can shape the behaviour of responder agencies during a prolonged crisis. In particular, the implications of our analysis for advancing our conceptual understanding of strategic decision-making during emergencies are discussed.  相似文献   
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