基于优化排污函数的节能发电调度方案

针对目前节能发电调度的排污函数较为粗略的问题,利用ASPEN PLUS对燃煤电厂的锅炉燃烧流程进行模拟,通过SPSS软件对燃烧所产生的污染物进行回归分析,得出更加细化的排污函数。利用该函数,以发电产生的环境成本及燃料成本最优为目标,建立调度模型,并对包含26个节点、6台发电机的系统进行算例分析,验证了该排污函数和调度方案的有效性。     

基于模糊影响图的油气长输管道工程环境经济损益分析研究

为了能够较为准确地描述随机影响因素对油气管道工程环境影响经济损益产生的联合概率分布,文章基于模糊影响图建立了油气长输管道工程环境经济损益分析模型。对模型的构建进行了描述,介绍了模糊影响图概率推理的具体算法,并通过实例对油气长输管道工程环境经济损益的不确定性进行了分析评价,结果证明,该模型应用于油气长输管道工程环境经济损益分析是切实可行的。     

Implementing electronic identification for performance recording in sheep: II. Cost-benefit analysis in meat and dairy farms

Costs and secondary benefits of implementing electronic identification (e-ID) for performance recording (i.e., lambing, body weight, inventory, and milk yield) in dairy and meat ewes were assessed by using the results from a previous study in which manual (M), semiautomatic (SA), and automatic (AU) data collection systems were compared. Ewes were identified with visual ear tags and electronic rumen boluses. The M system used visual identification, on-paper data recording, and manual data uploading to a computer. The SA system used e-ID with a handheld reader in which performances were typed and automatic uploaded to a computer. The use of a personal digital assistant (PDA) for recording and automatic data uploading, which transformed M in a SA system, was also considered. The AU system was only used for BW recording and consisted of e-ID, automatic data recording in an electronic scale, and uploading to a computer. The cost-benefit study was applied to 2 reference sheep farms of 700 meat ewes, under extensive or intensive production systems, and of 400 dairy ewes, practicing once- or twice-a-day machine milkings. Sensitivity analyses under voluntary and mandatory e-ID scenarios were also included. Benefits of using e-ID for SA or AU performance recording mainly depended on sheep farm purpose, number of test days per year, handheld reader and PDA prices, and flock size. Implementing e-ID for SA and AU performance recording saved approximately 50% of the time required by the M system, and increased the reliability of the data collected. Use of e-ID increased the cost of performance recording in a voluntary e-ID scenario, paying only partially the investment made (15 to 70%). For the mandatory e-ID scenario, in which the cost of e-ID devices was not included, savings paid 100% of the extra costs needed for using e-ID in all farm types and conditions. In both scenarios, the reader price was the most important extra cost (40 to 90%) for implementing e-ID in sheep farms. Calculated extra costs of using the PDA covered more than 100% of the implementation costs in all type of sheep farms, indicating that this device was cost-effective for sheep-performance recording.     

北京市猪肉产业链各环节成本收益分析

通过对北京市猪肉产业链各环节相关主体进行深入调查,剖析了猪肉价格的形成过程以及各环节经营主体的成本收益情况.研究发现,一头生猪从养殖到屠宰最后进入到销售环节,利润在不同经营主体之间的分配从绝对量上来看,由高到低依次为零售、批发、屠宰、收购和养殖.     

电力市场下的需求响应研究

介绍了电力市场下的需求响应,包括需求响应的概念及其分类、需求响应成本和需求响应效益.分析了需求响应的短期市场影响效益、长期市场影响效益以及系统可靠性的效益等.同时,介绍了市场下的需求响应在国外的应用情况,并给出了在我国电力市场下实施需求响应的一些想法.     

水利事业预算项目绩效问题分析

政府财政预算支出的效果和效率问题当前受到社会高度关注.对预算项目的绩效评价是实行绩效预算的难点和制约瓶颈.通过水利事业预算项目有关绩效问题的分析,提出绩效指标设计思路与方法.     

Modeling Fault Coverage of Random Test Patterns

We present a new probabilistic fault coverage model that is accurate, simple, predictive, and easily integrated with the normal design flow of built-in self-test circuits. The parameters of the model are determined by fitting the fault simulation data obtained on an initial segment of the random test. A cost-based analysis finds the point at which to stop fault simulation, determine the parameters, and estimate fault coverage for longer test lengths. Experimental results on benchmark circuits demonstrate the effectiveness of this approach in making accurate predictions at a low computational cost. As compared to the cost of fault-simulating all the test vectors, the savings in computational time for larger circuits ranged from four to fourteen times. We also present an analysis of the mean and the variance of the fault coverage achieved by a random test of a given length. This analysis and simulation results demonstrate that while the mean coverage is determined by the distribution of the detectabilities of individual faults, the dual distribution of fault coverage of individual test vectors determines the variance.