广东核电站的人可靠性分析

人的可靠性分析是广东核电站PSA研究中的一个重要部分,其目的是研究电站中人的行为对反应堆堆芯熔化频率的影响,文章对广东核电站事故序列中可能出现的人误进行了定性和定量化分析,给出了PSA研究中需要的人误概率值。详细的人因分析将在以后的工作中进行。

基于相关性的人机系统可靠性模型

本文在剖析人机系统中操作者行为特征的基础上 ,考虑到操作者行为的自适应性、自学习能力及其行为形成主因子 ,着重结合操作者行为的相关性—感知作用于判断决策后影响到动作 ,建立了人机系统中操作者行为模式 ,并推导出计算操作者可靠度的公式 ,求出了相应参数。最后进行了实例量度 ,同时定量辨识了行为相关性对人可靠性的制约程度 。

加压注射法硬膜外穿刺的临床应用

判断硬膜外穿刺成功与否主要采用负压和悬滴试验。这种方法在小儿和老年人可靠性不及青壮年,而且有时出现假阳性,以致造成硬膜外阻滞失败。我院自1985年以来采用加压注射法后,取得了较好的效果,总结如下。 1 操作方法 硬膜外常规穿刺进针2～3cm,达棘间或黄韧带时,接上2ml注射器(内有生理盐水1ml。

APPLICATION OF HUMAN COGNITIVE MODEL FOR TIME DEPENDENT OPERATOR BEHAVIOR IN CHINESE NPP

This paper discusses some issues on human reliability model of time dependent human behavior. Some results of the crew reliability experiment on Tsinghua training simulator in China are given, Meanwhile, a case of calculation for human error probability during anticipated transient without scram (ATWS) based on the data drew from the recent experiment is offered.

Improved Mixed Integer Optimization Approach for Data Rectification with Gross Error Candidates

Mixed integer linear programming （MILP） approach for simultaneous gross error detection and data reconciliation has been proved as an efficient way to adjust process data with material, energy, and other balance constrains. But the efficiency will decrease significantly when this method is applled in a large-scale problem because there are too many binary variables involved. In this article, an improved method is proposed in order to gen- erate gross error candidates with reliability factors before data rectification. Candidates are used in the MILP objec- tive function to improve the efficiency and accuracy by reducing the number of binary variables and giving accurate weights for suspected gross errors candidates. Performance of this improved method is compared and discussed by applying the algorithm in a widely used industrial example.

Research on Oil/Gas In-pipe Inspection Robot

A new type of in-pipe mobile robot was designed and developed on the basis of w heel in-pipe robot and crawler in-pipe robot. The three sets of driving wheels circumferentially 120° apart in the cross section, both front and rear driving wheels are distributed on the same parallelogram mechanis m. The driving motor drives the three sets of driving wheels by worm couple, the regulating motor makes the three sets of driving wheels push against the pipe inwall with stable and adequate pressing force by the ball screw pair and p ressure sensor, so the in-pipe robot can provide adequate and stable traction force. The robot mechanism is simple and sm all in size and work reliably . It is particularly suitable to the pipe with diameter 400～650 mm.

Quantitative Human Reliability Analysis for Crew During Shipping Operation

A simplified bi-variable human error probability calculation method is developed by incorporating two common performance condition( CPC) factors, which are modified from factors employed in cognitive reliability and error analysis method(CREAM) to take into account the characteristics of shipping operations. After the influencing factors are identified, Markov method is used to calculate the values of human reliability. The proposed method does not rely on the involvement of experts in the field of human factor nor depend on historical accidents or human error statistics. It is applied to the case of the crew on board of an ocean going dry bulk carrier. The caculated results agree with the actual case, which verifies the validity of the model.

The Concept of Human Reliability Assessment Tool CREAM and Its Suitability for Shipboard Operations Safety

Shipboard operations as a hazardous process require the human element to be aware of any operation risks. Since the concept of human error exposed to ample arguments, the introduction of human element concerns to practices rather than other means is essential because the provenance of accidents is human error. HRA （human reliability assessment） is a theoretical framework to assess the human actions for predicting the potential human error probability of a certain given task or operation scenario. Furthermore, surveillance of the human performance is through the task by steps and sub-steps. The CREAM （cognitive reliability and error analysis method） tool is the second generation of HRA which emphasizes the features of the context and utilized as retrospective and prospective tool. The paper illustrates the basic and extended version of CREAM and its suitability for critical shipboard operations safety assessment.

Generation Reliability Assessment in Electricity Markets Using Cooperative and Non-cooperative Concepts and Intelligent Systems

Deregulation policy has caused some changes in the concepts of power systems reliability assessment and enhancement. In the present research, generation reliability is considered, and a method for its assessment is proposed using game theory and NN （neural networks）. Also, due to the stochastic behavior of power markets and generators＇ forced outages, MCS （monte carlo simulation） is used for reliability evaluation. Generation reliability merely focuses on the interaction between generation complex and load. Therefore, in the research, based on the behavior of players in the market and using game theory, two outcomes are considered： cooperation and non-cooperation. The proposed method is assessed on IEEE-Reliability Test System with satisfactory results. LOLE （loss of load expectation） is used as the reliability index and it will be shown that generation reliability in cooperation market is better than non-cooperation outcome.

A Multi-homed VPN Architecture Based on Extended SOCKS+TLS Protocols

A multi-homed VPN architecture based on extended SOCKSv5 and TLS was proposed. The architecture employs a dynamic connection mechanism for multiple proxies in the end system,i n which the security-demanded transmission connections can switch smoothly among the multiple proxies by maint aining a coherent connection context.The mechanism is transparent to application programs and can support th e building of VPN.With the cooperation of some other security components,the mechanism guarantees the reso urce availability and reliability of the end system against some attacks to the specific ports or hosts.

A component-based back-propagation reliability model with low complexity for complex software systems

Since most of the available component-based software reliability models consume high computational cost and suffer from the evaluating complexity for the software system with complex structures,a component-based back-propagation reliability model(CBPRM)with low complexity for the complex software system reliability evaluation is presented in this paper.The proposed model is based on the artificial neural networks and the component reliability sensitivity analyses.These analyses are performed dynamically and assigned to the neurons to optimize the reliability evaluation.CBPRM has a linear increasing complexity and outperforms the state-based and the path-based reliability models.Another advantage of CBPRM over others is its robustness.CBPRM depends on the component reliabilities and the correlative sensitivities,which are independent from the software system structure.Based on the theory analysis and experiment results,it shows that the complexity of CBPRM is evidently lower than the contrast models and the reliability evaluating accuracy is acceptable when the software system structure is complex.

A Statistical Analysis of Reliability of Audit Opinions as Bankruptcy Predictors

This research measures the reliability of audit firms in predicting bankruptcy for United States （US） listed financial institutions. The object of analysis is the going concern opinion （GCO）, widely considered as a bankruptcy warning signal to stakeholders. The sample is composed of 42 US listed financial companies that filed for Chapter 11 between 1998 and 2011. To highlight the differences between bankrupting and healthy firms, a matching sample composed of 42 randomly picked healthy US listed financial companies is collected. We concentrate on financial institutions, whereas the existing literature pays considerably greater attention to the industrial sector. This research imbalance is remarkable and particularly unexpected in the wake of recent financial scandals. Literature points out two main approaches on bankruptcy prediction： （1） purely mathematical; and （2） approaches based on a combination of auditor knowledge, expertise, and experience. The use of data mining techniques allows us to benefit from the best features of both approaches. Statistical tools used in the analysis are： Logit regression, support vector machines （SVMs）, and an AdaBoost meta-algorithm. Findings show a quite low reliability of GCOs in predicting bankruptcy. It is likely that auditors consider further information in supporting their audit opinions, aside from financial-economic ratios. The scant predictive ability of auditors might be due to critical relationships with distressed clients, as suggested by recent literature.

Reliability of Rapid Diagnostic Test （RDT） for Malaria among Pregnant Women in Ido-Ekiti, Western Nigeria

Background： Malaria is the commonest cause of anemia in pregnancy with severe consequence on the developing fetus. Recent clamor by the WHO for testing before treatment has driven a need to assess the effectiveness of available Rapid Diagnostic Tests （RDTs）. Objective： To determine the reliability of Rapid Diagnostic Tests （RDTs） for malaria among pregnant women booking in Federal Teaching Hospital, Ido-Ekiti, Nigeria. Materials and Methods： A cross-sectional study of 240 pregnant women were recruited at booking over a period of twenty weeks. A semi-structured questionnaire sought information about socio demographic data. Blood samples were taken for malaria and diagnosis was done using RDT and Microscopy. Results： Prevalence of malaria was 22.1% by microscopy and 27.5% by RDT. The sensitivity of RDT was 88.7% and specificity was 89.8%. The positive predictive value （PPV） of RDT was 71.2%, the Negative predictive value （NPV） of RDT was 96.6% and accuracy was 89.6%. The reliability of RDT was good （Kappa statistics = 0.731）. The reliability of RDTs when compared with that of Microscopy was also good （Kappa statistics = 0.722）. Conclusions： RDTs was an effective screening test for malaria among the respondents. Hence, primary care physician should utilize this resource by advocating for its availability.

A Factor Analysis of the Tourism in the Mexican Province of Michoacan

The tourism is a key branch in the world wide economy nowadays, and revenues account for one third of total income in the world. Many nations are trying to improve their tourism sector attracting more tourists every year in order to impact social welfare. This study addresses two research questions： （1） What are the factors that impact on tourism sector？ and （2） Does the tourism really impact on social welfare of the communities？ The objectives of this work are to analyze the variables that impact on the tourism in the Mexican providence of Michoacan and also to find out if the tourism sector is impacting on social welfare of the province, with the propose of answering this questions 41 variables were selected being 63 municipalities of Michoacan province in the case of study. Analysis Factorial of Correspondences （AFC） through the analysis of principal components methodology is employed in this article. The analysis is divided into five phases： （1） reliability testing; （2） the calculation of a matrix that expresses the joint variability of the variables; （3） extraction of the optimal number of factors; （4） the rotation of solutions for the ease of interpretation; and （5） the estimation of the scores graphically. The results showed that the variables that impact on tourism are several the most representative tourism infrastructure and complementary services restaurants, lodging with category five- and four- star travel, visitors foreign share of the Economic Active Population （EAP） in the tertiary sector, percentage of EAP women, percentage of economically active men and Gross Domestic Product （GDP） per capita among others. However the analysis of the Human Development Index （HDI） is not associated with the tourism variables

Dorsalis pedis arterialized venous flap for hand and foot reconstruction

Objective：To report the results of repair of skin defects in the extremities with arterialized venous flap harvested from the lateral aspect of the dorsum of the foot.Methods：Six cases of skin and soft tissue defects over the foot and hands were resurfaced by free arterialized venous flaps,including five patients with skin defects of the hands,and one with defects at the dorsum of the foot.The flaps were harvested from the lateral aspect of the dorsum of the foot with the sizes ranging from 2 cm×5.5 cm to 6 cm×11 cm.Two veins at the proximal margin of the flap were retained,one of which was anastomosed to a recipient bed artery to provide arterial inflow and the other was anastomosed to a recipient bed vein for venous outflow.Results：All flaps demonstrated mild edema and survived completely.Blisters appeared on four flaps.Using this technique,we achieved good functional and cosmetic results in this series.Conclusions：Dorsalis pedis arterialized venous flap with rich vascular communications could enhance peripheral perfusion and decrease congestion of venous flaps,thereby improves reliability and utility for extremity reconstruction.

Human Reliability Analysis Method on Armored Vehicle System Considering Error Correction

Human reliability analysis(HRA) is an expansion of man-machine engineering. It is also a new multidisciplinary based on behavioral science, cognitive science, information processing, system analysis and probability statistics in order to analyze, predict, reduce and prevent human errors. Firstly, the quantitative analysis model of HRA is proposed based on Markov process theory by using human error probability(HEP) and error correction cycle(ECC) as parameters. And human reliability evaluation criterion is built. Then, the HRA process considering error correction is proposed based on cognitive reliability and error analysis method(CREAM). Finally, according to the characteristics of armored vehicle system, common performance condition(CPC) in CREAM is improved.A reliability impact index is characterized by the overall contexts of tasks. Human reliability evaluation criterion of armored vehicle system is formulated. And the result of HRA is obtained based on the method presented in this paper. In addition, the relative weights are estimated by combining scale of 10/10—18/2 and analytical hierarchy process(AHP), and the triangular fuzzy number considering confidence factor and optimism index is adopted in order to reduce the subjectivity. The analysis results show that the method presented in this paper is reasonable and feasible. Meantime, the method can provide guidance for human reliability analysis of other weapon systems.

A robust and efficient structural reliability method combining radial-based importance sampling and Kriging

Simulation based structural reliability analysis suffers from a heavy computational burden, as each sample needs to be evaluated on the performance function, where structural analysis is performed. To alleviate the computational burden, related research focuses mainly on reduction of samples and application of surrogate model, which substitutes the performance function. However,the reduction of samples is achieved commonly at the expense of loss of robustness, and the construction of surrogate model is computationally expensive. In view of this, this paper presents a robust and efficient method in the same direction. The present method uses radial-based importance sampling (RBIS) to reduce samples without loss of robustness. Importantly, Kriging is fully used to efficiently implement RBIS. It not only serves as a surrogate to classify samples as we all know, but also guides the procedure to determine the optimal radius, with which RBIS would reduce samples to the highest degree. When used as a surrogate, Kriging is established through active learning, where the previously evaluated points to determine the optimal radius are reused. The robustness and efficiency of the present method are validated by five representative examples, where the present method is compared mainly with two fundamental reliability methods based on active learning Kriging.