基于可持续发展的区域矿产资源配置问题研究

本文基于矿产资源的有限性和不可再生性,确立了资源优化配置的多目标准则;在全面分析影响区域矿产资源优化配置的社会经济发展需求因素,区域资源基础及潜力因素,资源开发利用的能力和水平因素,区域生态环境承载力因素,资源安全储备因素,区域外资源可供性因素,配套资源及基础设施支持因素的基础上,建立了区域矿产资源合理开发规模和速度的评价指标体系和分析计算模型;就河北省矿产资源的合理开发问题进行了具体的实证分析,研究了多目标准则下区域矿产资源开发和利用在时间维度上的优化配置问题,为合理规划和调整区域矿产资源开发利用战略提供了有益参考。     

Explaining Real Commercial Rents Using an Error Correction Model with Panel Data

This paper presents rent models for retail and office property in the United Kingdom. Panel data are used covering eleven regions for 29 years, enabling us to overcome the limitations of a relatively short time series. We use an error correction model (ECM) framework to estimate long-run equilibrium relationships and short-term dynamic corrections. The combination of panel data and an ECM is an innovative approach that is still being developed in economics. We construct new supply series that combine infrequent stock data with more frequent construction data. Separate regional models are estimated for retail and office properties. The regions are then combined into a number of panels on the basis of the income and price elasticities in the long-run and short-run models. Unlike previous studies, we find no evidence of a board north–south divide between low growth and high growth regions. Like these studies we do find a London effect: in London, demand elasticities for space with respect to both price (rent) and income are much lower in magnitude. We conclude that, while the economic drivers may vary, there is no evidence of differences in the operation of the regional property markets outside London. Elasticities for retail and office are similar. Our final models are parsimonious with single measures of economic activity and of supply and always support the use of an ECM.     

容积式流量计有级容差调整在二维坐标系内的认识

以二维坐标系的方式，直观地分析了容差调整过程中流量计误差曲线坐标变化的情况，进而说明了有级容差调整的实质，并结合各专业厂家生产技术的实际情况，说明了调整齿轮选择表的正确使用。     

Real estate return correlations: Real-world limitations on relationships inferred from NCREIF data

Correlation estimates for returns between individual properties are subject to large inherent uncertainties due to limits on the amount of data that is likely to be available for the foreseeable future. After allowance for correlation sampling error, it is impossible to distinguish on an ex ante basis between the risk-reduction capabilities of mean-variance portfolio selection models and naive diversification without regard to property type or geographical location. The naive portfolio diversification strategies of typical institutional real estate portfolio managers are rational responses to limitations on the informational content of statistical analyses of historical real estate data.     

Inference with Dependent Data in Accounting and Finance Applications

We review developments in conducting inference for model parameters in the presence of intertemporal and cross‐sectional dependence with an emphasis on panel data applications. We review the use of heteroskedasticity and autocorrelation consistent (HAC) standard error estimators, which include the standard clustered and multiway clustered estimators, and discuss alternative sample‐splitting inference procedures, such as the Fama–Macbeth procedure, within this context. We outline pros and cons of the different procedures. We then illustrate the properties of the discussed procedures within a simulation experiment designed to mimic the type of firm‐level panel data that might be encountered in accounting and finance applications. Our conclusion, based on theoretical properties and simulation performance, is that sample‐splitting procedures with suitably chosen splits are the most likely to deliver robust inferential statements with approximately correct coverage properties in the types of large, heterogeneous panels many researchers are likely to face.     

Industry Costs of Equity: Incorporating Prior Information

I examine whether incorporating economically motivated prior information yields more accurate forecasts of industry costs of equity. I find that incorporating the long‐run mean of the Capital Asset Pricing Model (CAPM) parameters and the industry characteristics in the cross section produces more accurate parameter estimates, which subsequently translate into more accurate out‐of‐sample forecasts of industry costs of equity. The outperformance of this method over rolling‐window estimates becomes larger as the forecast horizon extends into the future. These findings provide evidence that the CAPM parameters have a long‐run mean‐reversion property and correlate with the industry characteristics in a systematic way.     

ETF Premiums and Liquidity Segmentation

Exchange traded funds (ETFs) provide a means for investors to access assets indirectly that may be accessible at a high cost otherwise. I show that liquidity segmentation can explain the tendency for ETFs to trade at a premium to net asset value (NAV) as well as the life‐cycle pattern in premiums. ETFs with larger NAV tracking error standard deviations (TESDs) tend to trade at higher premiums and the liquidity benefits offered by foreign ETFs and fixed income ETFs are revealed to be the most valuable to investors. Further tests validate that TESD has the desirable properties of a liquidity segmentation measure.     

The Effects of Oil Price on the Korean Economy: A Global VAR Approach

This article empirically explores the effects of oil price on the Korean economy using a Global VAR model. First, we evaluate the average connectedness of oil price with the Korean domestic variables over the precrisis period. We then investigate the time-varying contribution of oil price to the Korean financial and real sectors during and after the global financial crisis through recursive estimation. It is found that the contribution of oil price becomes very large in the case of real exports, equity prices, and real output, but plays a much less prevalent role in the remaining cases. In the meantime, the time-varying contribution of oil price to the Korean economy has not changed during and after the global financial crisis. Interestingly, we find that the Korean economy is affected mostly by overseas financial conditions in the short-term but it becomes more susceptible to oil price fluctuations in the long run, suggesting that Korea’s reliance on energy imports leaves the economy exposed to volatility in energy prices.     

An investigation of restaurant food safety performance: A comparison between ethnic and nonethnic and chain and independent restaurants in Louisiana

This study examines health inspection data from casual dining restaurants and compares differences of food code violations between ethnic and nonethnic restaurants. A total of 7,415 violations were retrieved from the restaurant inspection reports of 769 restaurants. Ethnic restaurants have more violations than nonethnic restaurant in categories related to food time/temperature violations, cross contamination, and food condition/surface/labels. Nonethnic and chain restaurants had fewer behavioral violations than ethnic and independently operated restaurants. Ethnic restaurants were 1.74 times more likely than nonethnic restaurants to have critical violations. Meanwhile, independent restaurants were 1.64 times more likely than chain restaurants to have critical violations.     

集装箱信息的条码化研究

现代集装箱码头很多作业已经实现了自动化或半自动化,但码头理货和闸口工作人员仍要用无线手提终端机人工输入集装箱信息。本文研究了使用条码技术(39条码和PDF417码)对集装箱信息进行编码。运用了文本压缩技术,将包含集装箱信息的PDF417码压缩为5行二维条码。通过将集装箱信息的条码化,并借助市场上已有的无线条码数据采集器扫描条码,可以实现码头理货和闸口工作人员录入数据的自动化,降低工作强度,提高生产效率。