基于组合赋权-集对分析的煤矿煤尘爆炸危险性评价研究

针对目前煤尘爆炸危险性评价研究较少、各评价因素选择偏差较大的问题,通过分析煤尘爆炸特性,提出以煤尘可爆性危险、煤尘爆炸浓度危险、点火源危险3个必要条件为一级指标,煤质变异程度、挥发分、水分、灰分等14个二级指标,以层次分析法确定各指标的主观权重,以熵权法确定各指标的客观权重,利用乘法归一化方法对各指标的组合权重进行计算,构建集对分析-组合赋权煤尘爆炸危险性评价模型,并将该模型与已较成熟的改进FAHP模型、模糊事故树模型、灰色聚类评估体系、未确知测度评价模型一同应用于济宁某矿的煤尘爆炸危险性评价过程中,结果显示:集对分析-组合赋权评价模型、改进FAHP模型、灰色聚类评估体系评价结果为一般危险等级,模糊事故树模型的评价结果为较安全等级,集对分析-组合赋权煤尘爆炸危险性评价模型评价结果与改进FAHP模型、灰色聚类评估体系、未确知测度评价模型的评价结果一致,该模型对煤尘爆炸危险的评价具有较好的适用性。     

"三下"煤炭资源回收难易程度的权重分析-模糊综合评价研究

详细分析了“三下”煤炭资源加收难易程度的影响因素，阐述了权重分析－模糊综合评判的基本原理，以建筑物下煤炭资源为例讨论了确定各影响因素权重的过程，在此基础上结合实例给出了“三下”煤炭资源回收难易程度的模糊综合评价过程，并进行了验证分析，为“三下”煤炭资源补偿费征收、“三下”煤炭资源评价与管理以及“三下”采煤方案的科学决策提供理论与方法依据。     

Weighting ensemble least-square method for flutter derivatives of bridge decks

In this paper, a reliable but simple identification method, here called the weighting ensemble least-square method (WELS), has been developed to extract all eight flutter derivatives of bridge deck from free vibration records. For every wind speed, free vibration test of section model is generally repeated several times in order to obtain more reliable parameter estimates. In the WELS method, many free vibration records at the same wind speed are regarded as an ensemble. The common mode parameters are then identified simultaneously from the ensemble data. The parameter fit is obtained by a nonlinear least-square method. Weighting factors are proposed to make each experiment record with the same weight in total residual error analysis. The ensemble composed of many records can reduce the effect of the colored noise of few records on the convergence of least-square iteration process. The flutter derivatives of two section models are identified to indicate the reliability and effectiveness of the WELS method.     

Problem of the reference height of the projectile trajectory as a reduced meteo-ballistic weighting factor

This paper deals with the issue of preparation of the aiming angles with the use of tabular firing tables and needed determination of the ballistic elements μB （ballistic wind wB Wxm WzB, ballistic （virtual） temperature τB, ballistic density ρB） from the standardized met messages. The weighting factors are used for the calculation of ballistic elementsμB that are incorporated into the trajectory calculations characteristics of weapon and ammunition. Two different methodologies practically used in the praxis are analysed and compared. For the comparison of the two methodologies the reference height of trajectory determined from the weighting factor functions is employed. On the basis of the analyses conducted, the potential for further increase in accuracy of these aiming angles preparation methods is pointed out.     

Using retrospective sampling to estimate models of relationship status in large longitudinal social networks

Estimation of longitudinal models of relationship status between all pairs of individuals (dyads) in social networks is challenging due to the complex inter-dependencies among observations and lengthy computation times. To reduce the computational burden of model estimation, a method is developed that subsamples the “always-null” dyads in which no relationships develop throughout the period of observation. The informative sampling process is accounted for by weighting the likelihood contributions of the observations by the inverses of the sampling probabilities. This weighted-likelihood estimation method is implemented using Bayesian computation and evaluated in terms of its bias, efficiency, and speed of computation under various settings. Comparisons are also made to a full information likelihood-based procedure that is only feasible to compute when limited follow-up observations are available. Calculations are performed on two real social networks of very different sizes. The easily computed weighted-likelihood procedure closely approximates the corresponding estimates for the full network, even when using low sub-sampling fractions. The fast computation times make the weighted-likelihood approach practical and able to be applied to networks of any size.     

Simulation of the anode structure for capacitive Frisch grid CdZnTe detectors

CdZnTe (CZT) capacitive Frisch grid detectors can achieve a higher detecting resolution.The anode structure might have an important role in improving the weighting potential distribution of the detectors.In this paper,four anode structures of capacitive Frisch grid structures have been analyzed with FE simulation,based on a 3-dimensional weighting potential analysis.The weighting potential distributions in modified anode devices (Model B,C and D) are optimized compared with a square device (Model A).In model C and D,the abrupt weighting potential can be well modified.However,with increased radius of the circular electrode in Model C the weighting potential platform away from the anode becomes higher and higher and in Model D,the weighting potential does not vary too much.     

关于空调冷冻水输送能效比计算的一点看法

本文针对在《公共建筑节能设计标准》（GB50189—2005）中提出的空调冷冻水输送能效比计算公式不能满足复杂、新型空调方式（如多级泵系统、冷辐射系统等）的要求，提出了根据空调计算冷负荷分布的“加权法”对整个水系统的输送能效比进行计算的新方式，供设计研究人员进行参考。     

A novel retrieval approach reflecting variability of syntactic phrase representation

In this paper, we introduce variability of syntactic phrases and propose a new retrieval approach reflecting the variability of syntactic phrase representation. With variability measure of a phrase, we can estimate how likely a phrase in a given query would appear in relevant documents and control the impact of syntactic phrases in a retrieval model. Various experimental results over different types of queries and document collections show that our retrieval model based on variability of syntactic phrases is very effective in terms of retrieval performance, especially for long natural language queries.     

电离辐射的生物效应——ICRP 60号出版物附件B内容简介及讨论

本文简要介绍了国际放射防护委员会(ICRP)1990年建议书(ICRP 60号出版物)附件 B 的主要内容,并对危险系数、组织权重因子及新的放射性核素年摄入量限值等有关问题进行了初步讨论。