军队安全管理中的脆性风险分析及其评估方法

安全管理作为部队日常管理的重要职能,对维持部队安全稳定具有重要作用.为全面分析其可能面临的风险威胁,促进军队安全管理模式转型,在分析军队安全事故的基础上,提出了基于脆性风险熵的安全管理脆性风险分析及评估方法.结合脆性传递原理,提出了安全管理对象间基于不同脆性关系和风险事件相关性的脆性概率计算方法;按照安全事故的分类原则,量化确定了军队管理对象的风险等级,并结合直觉模糊集的基本原理提出了相应的脆性风险量化方法.最后以某部某次危险品输送任务为例进行说明,梳理任务各执行阶段中的脆性传递关系及触发过程,并通过分析各管理对象的脆性风险熵及其脆性风险值变化验证脆性变化的基本规律,结果表明,其变化趋势满足安全管理对风险触发过程的认知.     

The concept of population and maximum difference between two results of analysis

 The concept of population, which is widely used in mathematical statistics, is discussed in relation to the calculation of maximum difference between two results of analysis (permissible range) which is an important parameter of quality for analytical methods. It is shown how the sample size can influence the results of the calculation.     

Laboratory accreditation – where next?

 Laboratory accreditation is now well established and can justly claim to have had a beneficial impact on the quality of the services provided by accredited laboratories. However, the needs of laboratories and their customers are continually evolving. It is necessary for accreditation practices to keep abreast of these changing requirements if they are to continue to be of benefit to laboratories and their customers. This paper gives a brief review of current accreditation practice and suggests some changes that should be made to help laboratories meet the demands made on them by their customers. Received: 2 July 1998 · Accepted: 3 August 1998     

Estimating the half-life of 241Pu and its uncertainty

Measuring the double isotope atomic abundance ratio as function of time of a homogenized stock of plutonium using mass spectroscopy provides a means to estimate the half-life of ²⁴¹Pu, denoted here as t_1/2,241. After a logarithmic transformation, estimating t_1/2,241 along with a justifiable associated uncertainty is reduced to the analysis of a linear relationship, as illustrated in this paper using 15 published data pairs (time, log(double isotope ratio)) of Wellum et al. (2009) that span approximately 31 years (greater than two half-lives). However, as noted by Wellum et al. (2009), the published 15 data pairs exhibit inconsistencies that indicate possible underestimation of individual experimental uncertainties. Similar inconsistencies often arise in multi-experiment comparisons of the same estimated quantity, typically because some components of uncertainty such as individual experimental biases are difficult to identify and assess. It is therefore an important and common problem. In such cases the experimental data must be supplemented with other information to make plausible uncertainty estimates. We therefore analyze the data pairs under several different assumptions regarding total experimental uncertainties and show quantitatively that the best estimate of t_1/2,241 and of its uncertainty depend on the assumptions regarding experimental uncertainties. It is unlikely in this context that the 15 data pairs and associated estimated experimental uncertainties could guide one toward a very certain choice among the reasonable sets of assumptions regarding total experimental uncertainties. Thus a definitive recommendation cannot be singled out. Fortunately, the best estimates and associated uncertainties arising from different yet tenable assumptions regarding experimental uncertainties are all in reasonably close agreement. And, one of those best estimates we provide (with approximately 95% confidence limits) is (14.329 ± 0.006[fit] ± 0.029[bias]) years, which uses similar data stratification arguments as in Wellum et al. (2009) but a completely different approach. Furthermore, this estimate of t_1/2,241 agrees closely with the value recommended in Wellum et al. (2009) of (14.325 ± 0.024) years. We conclude that the value of t_1/2,241 supported by the available data is robust, despite evidence of some non-ideal behavior, and that alternative means of estimating t_1/2,241 and its uncertainty yield reasonably similar results.     

Quality control techniques for chemical analysis: some current shortcomings and possible future developments

Current approaches to quality control in chemical analysis are examined. Issues that frequently cause problems are proposed. Future developments relating to ways in which the incidence of mistakes might be reduced are discussed as possible supplements to more well-established quality control measures.     

A general repeat inspection plan for dependent multicharacteristic critical components

A component is critical if it causes disaster or a very high cost upon failure. Multicharacteristic critical components exist in many systems. Such components could be a part of an aircraft, space shuttle, a special weapon system or a gas ignition system. In many situations, characteristics’ failures of these components are statistically dependent. In this paper, a new inspection plan for such components is proposed. A mathematical model that depicts the plan is developed and an example demonstrating the results of the model is given. The advantage of this model over the other model where independence of the characteristics’ failure is assumed for the case of dependency is illustrated. The model resulted in an average of 32.4% reduction in cost compared to the situation where the dependency case is solved assuming statistical independence.     

A quality of service negotiation-based vertical handoff decision scheme in heterogeneous wireless systems

This paper introduces a novel vertical handoff decision scheme. The objective is to provide users with enhanced quality of service (QoS) and maximize the network revenue. This scheme balances both-side interests via a suitably defined network merit function and a user–operator negotiation model. The merit function evaluates network performance based on user preferences and decides the most appropriate network for users. The negotiation model is defined as a semi-Markov decision process (SMDP). An optimal policy that maximizes the network revenue without violating QoS constraints is found by resolving the SMDP problem using Q-learning. Furthermore, a time-adaptive QoS monitoring mechanism is combined with the merit function in order to decrease the power consumption on terminal interface activation. The simulation results demonstrate that the proposed vertical handoff decision scheme enhances the performance in terms of power consumption, handoff call-dropping probability (HCDP) and network revenue.     

构建低碳经济下生产型企业业绩评价指标

发展低碳经济对生产型企业创新能源技术,发挥减排技术等方面提出了更高的要求。基于此,低碳经济下,生产型企业应从可持续健康发展的战略高度出发,结合企业自身情况,本着安全性、减量化、再利用、资源化的原则,重建业绩评价指标体系,引导和激励企业实现新的目标。     

A Product Shape Design and Evaluation Model Based on Morphology Preference and Macroscopic Shape Information

A product form design and evaluation model are proposed. In this method, the forms can be evaluated by three sub-evaluation models which can help designers to grasp consumers’ preferences. In the process, the overall shape is first disassembled into several shape elements, and a morphological chart is constructed. Then, the priority of shape elements is analyzed through the fuzzy analytical hierarchy process, and several required combinations are selected from a morphological chart. Moreover, the fuzzy comprehensive evaluation (I), preference questionnaire (II), and quadratic curvature entropy (III) of the selected combinations are analyzed. Finally, the results of I, II, and III are compared. In conclusion, the three sub-evaluation systems are consistent, which confirms the applicability of the proposed model.     

Determination of hydrocarbons in water – interlaboratory method validation before routine monitoring

The clarification of hydrocarbon input into the Baltic sea via rivers is one of the priority issues of the 4th Pollution Load Compilation (PLC-4) within the framework of international Baltic Sea marine monitoring. An interlaboratory comparison was conducted to check the applicability of a new method for the determination of hydrocarbons by solvent extraction and gas chromatography. Surrogate oil solutions with known hydrocarbon content were distributed among the participants for preparation of water samples of different hydrocarbon concentration. In using these concentrations as assigned values and by setting target values for precision, the proficiency of participating laboratories could be tested as a qualifying step before involvement in PLC-4 routine monitoring. The results of the exercise indicate that hydrocarbons in water samples can be monitored as a mandatory test item within the framework of PLC-4. Received: 31 October 2000 Accepted: 3 January 2001