汽车柴油发动机可靠性试验的重要性和必要性

文章针对当前汽车柴油发动机产品在可靠性方面存在的主要问题,结合国家试验标准,通过列举某台国产汽车柴油机可靠性试验中出现的故障情况及排除措施,纠正此类可靠性试验保养操作中的常见误区,阐明进行汽车柴油机可靠性试验的重要性和必要性。     

抽油机皮带张紧装置可靠性设计与改进

结合采油现场,通过综合分析抽油机调整皮带操作流程的表现形式,提出了研制抽油机皮带张紧装置,优化皮带轮传动系统结构,改变现有抽油机皮带调整方式的设计方案.应用FMEA方法对张紧系统、支架系统和从动系统进行故障模式影响分析,确定了经济合理、满足现场需要的改进方案.经过可靠性试验筛选,研制成功了抽油机皮带张紧装置,在实现手动张紧皮带的同时,弹簧自动复位张紧装置能够动态调整抽油机皮带的张紧度,可靠性增强,现场操作效率大大提高,推广应用前景广阔.     

质量可靠性技术在原油罐防腐中的应用

针对原油罐较易发生腐蚀的部位,从防腐涂料的选择、防腐蚀涂料的施工、罐底阴极保护等方面,阐述了提高油罐防腐性能的措施、新材料的应用及工程中应遵守的规则和注意事项等.在保证材料的可靠性、工艺的可靠性、人的可靠性、环境的可靠性的基础上,实现油罐防腐性能的可靠性.     

Reproducibility investigation of elicitation techniques in risk assessment for hydraulic turbines

Abstract

Certain elicitation techniques exert some control on expert opinions by leading them to a consensus or to a specific choice. In the absence of such guidelines, experts rely on their own knowledge to formulate opinions. This can result in large dispersions and affects the decision maker’s judgment. In this situation, we wonder what the relevant elicitation techniques are and how we can help experts to express their knowledge. From literature review, it is hard to decide if elicitation techniques are equivalent or not, which justifies the reproducibility analysis that we carry out in this paper. In this study, multiple experts have been involved in order to predict the defect size in hydraulic turbines, according to four proposed elicitation techniques. The comparison between these techniques was performed based on a suggested algorithm using the area metric concept. Our Findings show that elicitation techniques with ‘support’ tend to limit variations between experts and might be suitable only when prior knowledge on the expected elicited variable is available. Otherwise, we can end up with a distorted opinion of the elicited variable and an erroneous risk assessment.     

Domain-independent approach to risk reduction

Abstract

The popular domain-specific approach to risk reduction created the illusion that efficient risk reduction can be delivered successfully solely by using methods offered by the specific domain. As a result, many industries have been deprived of efficient risk reducing strategy and solutions. This paper argues that risk reduction is underlined by domain-independent methods and principles which, combined with knowledge from the specific domain, help to generate effective risk reduction solutions. In this respect, the paper introduces a powerful method for reducing the likelihood of computational errors based on combining the domain-independent method of segmentation and local knowledge of the chain rule for differentiation. The paper also demonstrates that lack of knowledge of domain-independent principles for risk reduction misses opportunities to reduce the risk of failure even in a mature field like stress analysis. The domain-independent methods for risk reduction do not rely on reliability data or knowledge of physical mechanisms underlying possible failure modes and are particularly well suited for developing new designs, with unknown failure mechanisms and failure history. In many cases, the reliability improvement and risk reduction by using the domain-independent methods reduces risk at no extra cost or at a relatively small cost. The presented domain-independent methods work across unrelated domains and this is demonstrated by the supplied examples which range from various areas of engineering and technology, computer science, project management, health risk management, business and mathematics. The domain-independent risk reduction methods presented in this paper promote building products and systems characterised by high-reliability and resilience.     

电力市场监管理论与实践的探讨

就市场成员市场力、串谋等问题分析了电力市场运营监管思路及其相关措施;在电力市场环境下。从电力系统安全运行导则、继电保护及安全控制原则、发电机组检修计划等方面分析了电力系统可靠性的监管思路及其相关措施;讨论了电力市场投机行为及其监管措施。     

提高软件可靠性的途径

从软件工程的角度出发,分析了软件开发过程中可能出现的软件错误类型和常见的软件故障,从中得出了一些提高软件可靠性的途径。     

中美会计信息质量特征比较

从结构、内容、主要质量特征的定义入手,对中美会计信息质量特征进行了比较,并提出了改进与完善我国会计信息质量特征的具体建议。     

Integrating expected coverage and local reliability for emergency medical services location problems

Daskin's MEXCLP model [Daskin M. A maximum expected covering location model: formulation, properties, and heuristic solution. Transportation Science 1983;17:48-70] was one of the first efforts to capture the stochastic nature of emergency medical services (EMS) location problems within a mixed-integer formulation. With their subsequent introduction of MALP, ReVelle and Hogan [The maximum availability location problem. Transportation Science 1989;23:192-200] offered two key advances, local vehicle busyness estimates and the α-reliability objective. While these constructs have influenced many subsequent EMS location models, they have been subjected to relatively little empirical analysis. To address this, we introduce the LR-MEXCLP, a hybrid model combining the local busyness estimates of MALP with the maximum coverage objective of MEXCLP. We then solve a series of problems with all three models and employ simulation to estimate aggregate service levels. We find that LR-MEXCLP leads to modest but consistent service gains over both MALP and MEXCLP. These results support the merits of local busyness estimates, but they also suggest that the α-reliability objective may be inappropriate when seeking to maximize aggregate system response capabilities. More generally, our research underscores the utility of (a) linking modeling assumptions and goals with real-world application contexts, and (b) employing simulation or other techniques to validate theoretical results.     

机构运动的可靠性设计

将可靠性概念引入机构设计，讨论了机构运动可靠性的数学模型及其求解方法。在综合过程中同时考虑综合方法本身带来的方法误差和构件尺寸制造误差及装配误差对机构输出构件运动精度的影响，使综合结果满足预定的运动可靠度要求，并给出了计算实例。