我国企业协会的覆盖率及其相关制度的再设计

企业协会要行使行业代表、行业管理职能必须具有高的行业覆盖率。由于形成的途经的不同和产业链的细分，我国许多行业中普遍存在着“一业多会”现象，导致了企业协会的覆盖率降低、内耗严重，协会的应有功能无法充分发挥。研究表明：走出“一业多会”困境的出路在于强制入会制度的实施、政府背景的隐退和业务主管部门的取消，以及政府行业管理职能的择优转移和“第三部门”的形成。     

矿量分级制式观念有待创新

始自1909-1910年通行各国的多种矿量分级制式,在原则上是都以所谓地质信息的可靠性为标志。本文所倡议的矿量分级制式,将以总开发效益的可靠性为标志另行构筑,它能使矿块"级别-吨位-品位"指标的内在联系从幕后走到前台,使勘查者的各级矿量与开采者的三级矿量贯通一气。"级差品位指标制"在国内运行四十多年的成效,就是在块段吨位足够大的前提下尊重"级别-品位"依存关系的例证。     

中国省际劳均收入的收敛研究——基于核密度函数和Markov随机过程理论的分析

采用核密度函数和Markov随机过程理论研究了我国省区劳均收入分布的动态演变和发展趋势。研究发现,改革前我国省区劳均收入为多峰分布,其遍历分布为偏向低收入的双峰分布;改革后,劳均收入分布经历了从多峰到单峰再到双峰的演变过程,其遍历分布为偏向高收入的双峰分布。从长期发展趋势看,改革后我国多数地区将会收敛于高收入区间。     

Traffic density,congestion externalities,and urbanization in China

ABSTRACT

Although there is an abundant regional literature analyzing traffic congestion, only a few studies have explored extending such analysis with spatial effects. This study uses a dynamic spatial Durbin model and city-level panel data for the period 2003–14 to investigate the spatial spillover effects of traffic congestion on urbanization in China. The results show that there is an inverted ‘U’-shaped relationship between urbanization and traffic density in local and neighbouring cities, and congestion effects have appeared. In the short and long run, the spatial effects of traffic congestion have become an important force restricting the effective promotion of urbanization in China.     

ASYMPTOTIC BEHAVIOR OF DISTRIBUTION DENSITIES IN MODELS WITH STOCHASTIC VOLATILITY. I

We study the asymptotic behavior of distribution densities arising in stock price models with stochastic volatility. The main objects of our interest in the present paper are the density of time averages of a geometric Brownian motion and the density of the stock price process in the Hull–White model. We find explicit formulas for leading terms in asymptotic expansions of these densities and give error estimates. As an application of our results, sharp asymptotic formulas for the price of an Asian option are obtained.     

Cost of skeletal-related events in European patients with solid tumours and bone metastases: data from a prospective multinational observational study

Abstract

Objectives:

Patients with bone metastases often experience skeletal-related events (SREs: radiation or surgery to bone, pathologic fracture, and spinal cord compression). This study examined health resource utilization and costs associated with SREs.

Methods:

Data presented are from the European cohort (Germany, Italy, Spain, and the UK) of patients with solid tumours enrolled in a multi-national, prospective, observational study in patients with solid tumours or multiple myeloma. Patients with Eastern Cooperative Oncology Group score 0–2 and life expectancy ≥6 months, who experienced an SRE up to 97 days before enrolment, were eligible. Health resource utilization associated with SREs (including number/length of inpatient stays, numbers of procedures and outpatient visits) were collected through chart review for up to 97 days before enrolment and prospectively during follow-up. Country-specific cost calculations were performed.

Results:

In total, 478 eligible patients contributed 893 SREs to this analysis. Radiation to bone occurred most frequently (66% of total). Spinal cord compression (7%) and surgery to bone (10%) were the least common events, but most likely to require inpatient stays. The most costly SREs were also spinal cord compression (mean per SRE across countries, €4884–€12,082) and surgery to bone (€3348–€9407). Inpatient stays were the main cost drivers.

Limitations:

Health resource utilization used to calculate the costs associated with SREs may have been under-estimated as a result of exclusion of patients with low performance status or life expectancy; unavailable information and exclusion of resource consumption associated with pain. Thus, the estimate of associated costs is likely to be conservative.

Conclusions:

SREs result in considerable health resource utilization, imposing a substantial financial burden driven by inpatient stays. Treatments that prevent/delay SREs may help ease this burden, thereby providing cost savings across European healthcare systems.     

The Distributional Properties of the Debt to Equity Ratio: Some Implications for Empirical Research

The purpose here is to assess empirically the quasi-supply side model of the firm developed in the paper by Ashton et al. (2004 ) by testing the prediction of the model that the evolution of a firm's debt to equity ratio will be compatible with a non-linear (target adjustment) process whose underlying probability density function possesses no convergent moments. Using a thirty-two-year history of the debt to equity ratio for each of ninety 'mature' United Kingdom firms, a non-parametric estimation procedure shows that the debt to equity ratio evolves in terms of a process which is largely consistent with the predictions of this model. In particular, the evolution of the debt to equity ratio is compatible with a 'long (fat) tailed' density function with no convergent moments. This has the important implication, supported by our empirical analysis, that the linear dynamic models which characterize empirical work in this area will be mis-specified and will return inconsistent and temporally unstable estimates of the target adjustment process as a consequence.     

双峰聚乙烯的质量模型研究

在乙烯聚合反应机理的基础上,建立了采用环管反应器-流化床反应器串联工艺生产的双峰聚乙烯的熔体流动速率和密度的预测模型,并采用来自生产过程的动态响应数据对模型进行了优化。结果表明,该模型能够较好地预测双峰聚乙烯的熔体流动速率和密度,精度符合工业化生产要求,并可与先进控制技术相结合对产品的质量进行在线测控。     

提高热敏打印机性能的新方法

打印密度和打印速度是衡量一台打印机性能的重要指标,文章论述了如何在打印机原有硬件结构基础上,通过改变打印头电机驱动控制方式来提高打印密度;采用软件优化设计,优化打印头移动轨迹,加快打印速度,从而提升打印机性能。     

购销广告中的数学学问

本文通过对需求市场的分析，得出人们的潜在购买量随广告费的增加而增大。但实际需求量是随机的。为使问题简化，并做出定量分析，本文假定实际需求量服从均匀分布，并用数学方法确定广告费和购进量的最优值。