北京华商大厦蓄冰空调系统DSM效益研究

蓄冰空调用电技术是电力需求侧管理(DSM)的一项重要措施。通过对北京华商大厦蓄冰空调系统的调查分析,得到了系统日/年用电量、用电能耗、日/年削峰电量、单位面积制冷负荷、单位温升制冷负荷、项目投资回收期等多项技术经济指标及结论,为推广蓄冰空调用电技术和制订各项政策提供了参考依据。     

典型地区大气光学湍流测量与模式研究

在东南沿海地区、合肥地区和西北干旱地区进行了常规气象参数和光学湍流的测量.从地域气候上分析三个实验点所具有的典型特征.分析了不同下垫面对近地面光学湍流强度的影响,提出了近地面和高空光学湍流估算方法,并探讨了光学湍流的预报模式.Bulk方法可用于估算陆地和海面上的Cn2.通过对输入参数进行适当调整,近地面湍流预报模式估算结果和实际测量结果在量级和变化趋势上较为一致.可以用常规气象参数估算光学湍流廓线,合肥上空的光学湍流可以用Hufnagel模式进行拟合.     

风电场风能资源评估几个关键问题分析

正确科学地对风资源进行评估,意义重大。针对我国风电场工程可行性研究报告的现状和GB/T 18709—2002《风电场风能资源测量方法》、GB/T 18710—2002《风电场风能资源评估方法》、《全国风能资源评价技术规定》等的某些条款进行了阐述,指出目前风资源评估中存在的一些问题并提出了一些建议,希望为以后的相关工作人员提供一个参考。     

光导管照明系统设计及工程应用

从天然采光的理念着手,介绍了光导管照明系统的概念,对系统中各部件的构成作了简要说明,并对光导管系统与传统照明的节能进行了分析比较。结合某工程现场要求,提出光导管照明系统设计思路和方案,并实际投入应用,随后对不同时段及不同天气条件下光导管照明效果进行测评及分析。结合工程实际状况及局限性,对工程上光导管系统设计及广泛应用提出建议,以期为同行提供参考。     

安全区代表工作思路探讨

从安全区代表的定义出发，对安全区的定义、安全区代表的产生、安全区代表的权利、安全区代表与安全员的联系与区别进行了分析，对安全区代表的人数设置以及任职条件进行了探讨。     

Numerical strategy for unbiased homogenization of random materials

This paper presents a numerical strategy that allows to lower the costs associated to the prediction of the value of homogenized tensors in elliptic problems. This is performed by solving a coupled problem, in which the complex microstructure is confined to a small region and surrounded by a tentative homogenized medium. The characteristics of this homogenized medium are updated using a self‐consistent approach and are shown to converge to the actual solution. The main feature of the coupling strategy is that it really couples the random microstructure with the deterministic homogenized model, and not one (deterministic) realization of the random medium with a homogenized model. The advantages of doing so are twofold: (a) the influence of the boundary conditions is significantly mitigated, and (b) the ergodicity of the random medium can be used in full through appropriate definition of the coupling operator. Both of these advantages imply that the resulting coupled problem is less expensive to solve, for a given bias, than the computation of homogenized tensor using classical approaches. Examples of 1‐D and 2‐D problems with continuous properties, as well as a 2‐D matrix‐inclusion problem, illustrate the effectiveness and potential of the method. Copyright © 2013 John Wiley & Sons, Ltd.     

Effectiveness of UK motorway services areas in reducing sleep-related and other collisions

In the UK, motorway service areas (MSAs) are believed to be helpful in reducing sleep (‘fatigue’) related collisions (SRCs), however, their actual effectiveness has yet to be evaluated. During a 2-3-year period, and over two sections of UK motorways comprising 14 MSA sites, assessments were undertaken of all fatal and injury road traffic collisions (RTCs), especially SRCs. Analyses examined whether there was: (i) a reduction in collisions 16 km beyond MSAs compared with the same distance beforehand; (ii) accumulation of collisions with increasing inter-MSA distances. Within the 16 km regions there was a non-significant fall in all RTCs from 355 before MSAs, to 304 afterwards. However, the 22% decrease in SRCs (108 vs. 84) was significant. Cars comprised the greatest reduction in SRCs possibly attributable to a MSA. Including and beyond these 16 km regions, there was no correlation between inter-MSA distances and accumulated RTCs or SRCs (n = 682 of which 181 were SRCs [26%]). There were obvious differences between MSAs in all these respects. Of the 23 fatal RTCs, 17 were SRCs. Whilst SRCs had their greatest daily incidence between 02:00 h and 06:00 h, as expected, MSAs seemed to have their least beneficial effect on SRCs during this vulnerable period, which is a matter for concern.     

2011年11月十大重要安全漏洞分析

国家计算机网络入侵防范中心在该文中介绍了2011年11月份的网络安全漏洞的整体情况,分别统计了“紧急”、“高”、“中”、“低”不同威胁级别的漏洞数量,并从中选取了十个重要安全漏洞,对其内容和危害进行了分析,进而提出了应对的措施.     

Estimating daily fat yield from a single milking on test day for herds with a robotic milking system

The objective of this study was to estimate the daily fat yield and fat percentage from one sampled milking per cow per test day in an automatic milking system herd, when the milking times and milk yields of all individual milkings are recorded by the automatic milking system. Multiple regression models were used to estimate the 24-h fat percentage when only one milking is sampled for components and milk yields and milking times are known for all milkings in the 24-h period before the sampled milking. In total, 10,697 cow test day records, from 595 herd tests at 91 Dutch herds milked with an automatic milking system, were used. The best model to predict 24-h fat percentage included fat percentage, protein percentage, milk yield and milking interval of the sampled milking, milk yield, and milking interval of the preceding milking, and the interaction between milking interval and the ratio of fat and protein percentage of the sampled milking. This model gave a standard deviation of the prediction error (SE) for 24-h fat percentage of 0.321 and a correlation between the predicted and actual 24-h fat percentage of 0.910. For the 24-h fat yield, we found SE = 90 g and correlation = 0.967. This precision is slightly better than that of present a.m.-p.m. testing schemes. Extra attention must be paid to correctly matching the sample jars and the milkings. Furthermore, milkings with an interval of less than 4 h must be excluded from sampling as well as milkings that are interrupted or that follow an interrupted milking. Under these restrictions (correct matching, interval of at least 4 h, and no interrupted milking), one sampled milking suffices to get a satisfactory estimate for the test-day fat yield.     

基于测试需求集的测试用例集极小化算法

测试用例集约简技术是生成最小测试用例集，最大限度地对软件进行科学有效的测试，从而降低软件测试的成本、提高测试效率的关键技术之一、结合国内外几种算法的策略的基础上，提出了一种基于测试需求集的最小测试用例集的生成方法，该方法能够保证得到优化代表集。