高管配置、非效率投资与内部控制关系--基于上市家族企业的经验证据

针对中国家族企业内部控制对投资效率的治理作用问题,以2010—2013年上市家族企业为研究样本,从内部控制这一视角出发,结合家族企业特征引入高管配置要素,将微观的内部控制与宏观的公司治理结合起来,系统考察企业的非效率投资与内部控制之间的关系。研究结果表明：在其他条件一定的情况下,内部控制能有效抑制企业的非效率投资,且对于高管集权的家族企业,这种抑制作用得到大大增强,反之则抑制作用不明显。此外,当高管由家族人员担任时,内部控制对非效率投资的抑制作用得到显著的提升,而当高管由非家族人员担任时,这种抑制作用并不显著。     

中国网络游戏产业集中度分析

产业集中度是研究产业市场结构的重要指标,对研究网络游戏产业市场组织有着重要作用。通过对2006年到2011年第一季度中国网络游戏市场的集中度计算得出目前我国网络游戏市场产业集中度较高属于垄断竞争的产业。在对我国网游产业的集中度形成原因进行分析的基础上对未来产业发展提出预测及政策建议。     

A concentration study of principal components

Influence functions are commonly used as diagnostic tools in order to investigate sensitivity aspects in principal component analysis. This paper suggests a practical alternative for the eigenvalues by introducing a sensitivity measure derived from the classical Lorenz curve and associated Gini index. The results are illustrated by analysing an example.     

Improved estimators for the location of double exponential distribution

In this paper, attention is focused on estimation of the location parameter in the double exponential case using a weighted linear combination of the sample median and pairs of order statistics, with symmetric distance to both sides from the sample median. Minimizing with respect to weights and distances we get smaller asymptotic variance in the second order. If the number of pairs is taken as infinite and the distances as null we attain the least asymptotic variance in this class of estimators. The Pitman estimator is also noted. Similarly improved estimators are scanned over their probability of concentration to investigate its bound. Numerical comparison of the estimators is shown.     

新型农村合作医疗制度公平性研究——基于黑龙江省农村新型合作医疗试点县的实证分析

利用黑龙江省林甸县和呼兰县607户农村居民的调查数据，对黑龙江省新型农村合作医疗制度公平性进行了研究。结果表明，在健康公平性和卫生服务利用公平性方面，新型农村合作医疗参加组居民优于未参加组；在卫生筹资公平性方面，未参加组居民优于参加组，说明合作医疗资金筹资制度设计仍没有实现垂直公平。建议采取划分农民等级、缴纳不同费用的办法实现合作医疗筹资的垂直公平。     

海峡两岸农产品贸易结构研究

对两岸农产品贸易现状分析后发现,两岸农产品贸易结构存在以下特点:产业内贸易程度低、贸易产品集中度高、比较优势产品贸易增长较快。在此基础上提出建议:(1)在ECFA框架下积极发展两岸农产品贸易;(2)两岸有关部门应统筹安排相关产品进出口;(3)减少不确定因素对两岸农产品贸易关系的影响;(4)建立台湾农产品市场消费、农产品贸易等数据库。     

Application of Geostatistics to Risk Assessment

Geostatistics offers two fundamental contributions to environmental contaminant exposure assessment: (1) a group of methods to quantitatively describe the spatial distribution of a pollutant and (2) the ability to improve estimates of the exposure point concentration by exploiting the geospatial information present in the data. The second contribution is particularly valuable when exposure estimates must be derived from small data sets, which is often the case in environmental risk assessment. This article addresses two topics related to the use of geostatistics in human and ecological risk assessments performed at hazardous waste sites: (1) the importance of assessing model assumptions when using geostatistics and (2) the use of geostatistics to improve estimates of the exposure point concentration (EPC) in the limited data scenario. The latter topic is approached here by comparing design-based estimators that are familiar to environmental risk assessors (e.g., Land's method) with geostatistics, a model-based estimator. In this report, we summarize the basics of spatial weighting of sample data, kriging, and geostatistical simulation. We then explore the two topics identified above in a case study, using soil lead concentration data from a Superfund site (a skeet and trap range). We also describe several areas where research is needed to advance the use of geostatistics in environmental risk assessment.     

基于县域经济范围的山西中小企业产业集聚度研究

首先采用企业数量集中度系数、就业人数区位熵等产业集聚度相关测度指标考察了山西省县域经济中中小企业的产业集聚度,得到了山西县域经济中小企业产业集群的分布现状;其次,根据分布现状绘制出了山西县域经济产业集群分布示意图;最后,对山西中小企业产业集群的分布规律与发展趋势作了进一步探究和总结.     

Derivation of Noncancer Reference Values for Acrylonitrile

Dose‐response assessments were conducted for the noncancer effects of acrylonitrile (AN) for the purposes of deriving subchronic and chronic oral reference dose (RfD) and inhalation reference concentration (RfC) values. Based upon an evaluation of available toxicity data, the irritation and neurological effects of AN were determined to be appropriate bases for deriving reference values. A PBPK model, which describes the toxicokinetics of AN and its metabolite 2‐cyanoethylene oxide (CEO) in both rats and humans, was used to assess the dose‐response data in terms of an internal dose measure for the oral RfD values, but could not be used in deriving the inhalation RfC values. Benchmark dose (BMD) methods were used to derive all reference values. Where sufficient information was available, data‐derived uncertainty factors were applied to the points of departure determined by BMD methods. From this assessment, subchronic and chronic oral RfD values of 0.5 and 0.05 mg/kg/day, respectively, were derived. Similarly, subchronic and chronic inhalation RfC values of 0.1 and 0.06 mg/m³, respectively, were derived. Confidence in the reference values derived for AN was considered to be medium to high, based upon a consideration of the confidence in the key studies, the toxicity database, dosimetry, and dose‐response modeling.     

血糖近红外光谱分析中两种常用化学计量学方法的比较

采用主成分回归和偏最小二乘法分别对血糖近红外光谱进行分析,建立数学校正模型。主成分回归模型的相关系数为 0 9294,偏最小二乘法模型相关系数为 0 9998。对两种方法进行比较,确定对血糖近红外光谱分析的方法。