南京市失业人口状况分析

根据"五普"南京市人口10%抽样调查数据,对南京市失业人口状况作了统计分析.分析结果表明,失业人口约占"非在业人口"的1/10略多,其中近2/3为"寻求再就业"人员.人口抽样失业率为6.08%,城区失业率较高,老城区人口失业问题更严重.15～25岁初次寻求就业和40～45岁寻求再就业的群体为两个"就业困难年龄段".女性群体在就业上处于明显弱势,其中25～45岁女性失业比例显著高于男性.但在初次寻找工作中,年轻男性碰到的困难大于年轻女性,而在失业后寻求再就业过程中,女性的困难远高于男性.     

Estimation of the mean of the exponential distribution using moving extremes ranked set sampling

Moving Extremes Ranked Set Sampling (MERSS) is a useful modification of Ranked Set Sampling (RSS). Unlike RSS, MERSS allows for an increase of set size without introducing too much ranking error. The method is considered parametrically under exponential distribution. Maximum likelihood estimator (MLE), and a modified MLE are considered and their properties are studied. The method is studied under both perfect and imperfect ranking (with error in ranking). It appears that these estimators can be real competitors to the MLE using the usual simple random sampling (SRS).     

Causes of accidents and the time of day

Abstract

The relationship between accidents and the time of day is not entirely clear. Although there is considerable evidence that performance is poorest in the early morning hours compared to at all other times, the degree to which this is translated into accidents is not understood. In this study work-related fatal accidents were analysed to determine whether the causes of these accidents vary with time. The analysis used a classification and coding system devised to describe the wider circumstances of the causes of fatalities. In terms of absolute numbers, fatalities were most common in the late morning or early afternoon. When these results were expressed in terms of the estimated number of workers at work, the proportion of fatal accidents occurring at night was more than double that occurring during the day. Behavioural factors were the most common cause of fatalities at all times, but most common in the early hours of the morning. Further analysis of the nature of the behavioural involvement showed that errors in automatic processing (skill-based errors) were the most common types of error and did not vary much with time of day. Rule-based errors were most common during the day whereas knowledge-based errors occurred mainly in the afternoon and night shifts. These results cast some doubt on the assumption that there is a direct relationship between the previously observed variations in performance across time and the ultimate safety outcome.     

Cu~(2+)的柠檬酸配合物与大环配体交换反应的研究

本文在λ=760nm,I=0.5×10~3mol/m~3(KNO_3),T=25℃,[Cu~(2+)]_(tot)=10[CyH]_(tot),和pH为3.30、3.50条件下,测定了大环配体5,5,7,12,12,14-六甲基-1,4,8,11-四氮杂环十四烷-N′-乙酸(简写为CyH)与Cu~(2+)的柠檬酸(LH_3)配合物配体交换反应。用ELORMA等计算程序算出假一级反应的表现速率常数k_(obs)以及双分子反应速率常数k_(Cu)~(CyH)和k_(CuL)~(CyH),且得到了相应的关系式。     

Further results in the optimal policy for imperfect inspection in discrete time

The paper reports investigations into how the optimal inspection interval for a fallible system with imperfect inspection is best determined. This work can be viewed as an extension of Raz and Ladany's 1992 work on imperfect inspection in discrete time. Here the cost functions are rewritten to include a probability conditioning that was omitted. In addition, an upper bound on the search space for the optimal inspection interval is presented. This bound allows one to find the global optimum with very modest computational effort. Insights gained from this bound and from the computational tests are used to present some general properties of the system.     

紫外线对水牛瘤胃真菌致死率的研究

本文采用在4℃冷却处理1—2h后的萌动孢子液经紫外线(Ultraviolet.UV)照射的方法,对水牛瘤胃真菌(Rumen fungi.RF)的诱变育种条件(主要是致死率与处理时间之间的关系)作了初步的研究。其结果为:致死率为100％、94.4％、70％、50％时,其相应的处理时间分别为8 min、3 min、1.67 min、1 min。     

对比分析理论与错误分析理论在大学英语教学中的应用

外语学习过程中由于受到母语和其它因素的干扰,不可避免的会出现错误,对比分析理论与错误分析理论对如何认识错误,分析错误和改正错误做出了不同的解释。本文从元认知策略着手,以学生遇到的实际困难为例,比较分析了师生在应用两种理论方面的具体情况,并对CA和EA在大学英语教学的应用提出了几点建议。     

Effects of Remanufacturable Product Design on Market Segmentation and the Environment

Despite documented benefits of remanufacturing, many manufacturers have yet to embrace the idea of tapping into remanufactured‐goods markets. In this article, we explore this dichotomy and analyze the effect of remanufacturable product design on market segmentation and product and trade‐in prices by studying a two‐stage profit‐maximization problem in which a price‐setting manufacturer can choose whether or not to open a remanufactured‐goods market for its product. Our results suggest that it is optimal for a manufacturer to design a remanufacturable product when the value‐added from remanufacturing is relatively high but product durability is relatively low and innovation is nominal. In addition, we find that entering a remanufactured‐goods market in and of itself does not necessarily translate into environmental friendliness. On the one hand, the optimal trade‐in program could result in low return and/or remanufacturing rates. On the other hand, a low price for remanufactured products could attract higher demand and thereby potentially result in more damage to the environment. Meanwhile, external restrictions imposed on total greenhouse gas emissions draw criticism in their own right because they risk stifling growth or reducing overall consumer welfare. Given these trade‐offs, we therefore develop and compare several measures of environmental efficiency and conclude that emissions per revenue can serve as the best proxy for emissions as a metric for measuring overall environmental stewardship.     

对转型期中国犯罪实际发案情况的估测

本文以联合国犯罪受害调查和公安部的立案不实调查为依据,对我国1978年以来犯罪的实际发案情况进行了估测。考虑到有许多犯罪案件发生后受害人没有报案以及立案不实顽症的客观存在,我国的犯罪问题实际上比以立案数为标准的统计值所反映的情况要严重得多。2004年全国犯罪发案数、犯罪率分别达到约2348万起、1800起／10万人,分别比同年犯罪立案数统计值 (471．8万起)和犯罪率统计值(363起／10万人)高4倍。不过,我国的犯罪率仍然低于世界平均水平。     

虚拟经济探微

随着发达国家经济虚拟化程度的加深 ,全球经济在运行过程中出现了许多新问题 ,这使得国内外许多学者越来越重视对虚拟经济问题的研究。从系统科学的角度看 ,虚拟经济是与实体经济相对应而在经济系统中存在的经济活动模式。虚拟经济的发展经历了闲置货币的资本化、生息资本的社会化、有价证券的市场化、金融市场的国际化和国际金融的集成化五个发展阶段。虚拟经济系统具有复杂性、介稳性、高风险性、寄生性和周期性的特性