餐饮业在吉林省经济发展中的重要作用

餐饮业是满足人们对饮食方面需求的行业。“民以食为天”。餐饮业的快速发展满足了人们对吃好、喝好的要求,提高了人们的生活质量和消费水平,同时也促进了农业、农产品加工业、旅游业和会展业的发展。     

基于KPCA-SVM的公路客运量预测研究

支持向量机(Support Vector Machine,SVM)是建立在统计学习理论和结构风险最小化准则基础上的机器学习方法,该方法可以较好的解决以往很多学习方法的小样本、高维数、非线性和局部最小点等实际问题.本文利用支持向量机(SVM)回归理论和方法,建立基于核函数主成分支持向量机(Kernel Principal Component Analysis-Support Vector Machine,KPCA-SVM)回归模型,并用2000-2008年杭州市公路客运量为样本进行了预测,结果表明,KPCA-SVM模型具有较高的预测精度和可靠性,是一种有效的公路客运量预测方法.     

中国股市波动与成交量动态关系研究——基于分位数回归的角度

研究股市波动与成交量之间的动态关系对于了解股市的信息传导机制与微观结构有重要意义.本文基于广义混合分布假说理论,利用分位数回归方法对中国股市上证综指1994年1月至2007年12月的资料进行实证研究,结果发现:中国股市波动具有长期的持续性,负向消息对股市波动的影响大于正向消息;成交量与股市波动之间呈现显著的正向关系,即较大(小)的波动伴随着较大(小)的交易量,且这种关系随着波动增加而逐渐增强,同时具有不对称的特点.相对于传统实证方法,分位数回归对二者的动态关系提供了更完整的描述,能够弥补以往研究的不足.     

Trading frequency and event study test specification

We examine the effects of thin trading on the specification of event study tests. Simulations of upper and lower tail tests are reported with and without variance increases on the event date across levels of trading volume. The traditional standardized test is misspecified for thinly traded samples. If return variance is unlikely to increase, then Corrado's rank test provides the best specification and power. With variance increases, the rank test is misspecified. The Boehmer et al. standardized cross-sectional test (Event-study methodology under conditions of event-induced variance, Journal of Financial Economics 30, pp. 253–272) is properly specified, but not powerful, for upper-tailed tests. Lower-tailed alternative hypotheses can best be evaluated using the generalized sign test.     

THE GENERAL STRUCTURE OF OPTIMAL INVESTMENT AND CONSUMPTION WITH SMALL TRANSACTION COSTS

We investigate the general structure of optimal investment and consumption with small proportional transaction costs. For a safe asset and a risky asset with general continuous dynamics, traded with random and time‐varying but small transaction costs, we derive simple formal asymptotics for the optimal policy and welfare. These reveal the roles of the investors' preferences as well as the market and cost dynamics, and also lead to a fully dynamic model for the implied trading volume. In frictionless models that can be solved in closed form, explicit formulas for the leading‐order corrections due to small transaction costs are obtained.     

污水处理厂的脱氮除磷改造

结合城镇污水处理厂脱氮除磷改造工程实例，对老氧化沟进行功能区划分、设备改造：增加好氧区溶解氧浓度，降低缺（厌）区溶解氧浓度；同时适当增容，延长氧化沟水力停留时间和污泥泥龄。运行结果表明，系统出水主要指标稳定达到GB18918—2002一级A标准。     

箱式变电所在住宅小区中设计应注意的问题

箱式变电所以其显著优点,在住宅小区建设(改造)中得到推广应用。文章以南宁市某住宅小区为例,论述箱式变电所设计中应注意的问题。     

基于趋势分解的机场季节旅客吞吐量预测方法

针对机场季节旅客吞吐量的特点,提出了基于趋势分解的机场季节旅客吞吐量预测方法,其基本思想是:首先根据机场季节旅客吞吐量历史数据的移动平均数,计算平均季节指数并进行修正,然后构建机场季节吞吐量趋势变动模型,从而构建航线季节客运需求分析模型。仿真结果表明该方法可行且结果具有较高的精度,可作为预测机场季节旅客吞吐量的有效工具。     

The Expiration Effects of Stock-Index Derivatives: Empirical Evidence from the Taiwan Futures Exchange

Five index derivatives with the same expiration days, settlement days, and settlement systems have been consecutively traded on the Taiwan Futures Exchange (TAIFEX) since 1998. This paper examines the expiration effects of TAIFEX index derivatives on the underlying stock market between 1998 and 2002. Our empirical findings show no significant expiration effects on the expiration day, but evidence demonstrates that expiration effects have strengthened as more relative index derivatives are listed on the TAIFEX. Meanwhile, the expiration effects seem to shift to the opening of the settlement day. In general, the expiration effects in Taiwan are not as significant as those in U.S. markets but are stronger than those in the Hong Kong market. The special settlement procedures adopted by the TAIFEX may account for the difference.     

Tourism's climate mitigation dilemma: Flying between rich and poor countries

Stronger demand for medium- to long-haul air transport is the main driver of the tourism industry's increasing greenhouse gas (GHG) emissions, causing the current development of global tourism to be environmentally unsustainable. Efficiency improvements and biofuel usage are unlikely to maintain pace with the projected growth in transport volume. Therefore, curbing the growing demand for air transport has been suggested as another option for the sustainable development of tourism. However, the political and industry discourse concerning the restriction of air transport tends to label such a restriction as unethical, as such limits would impair the development that tourism brings to poor countries. This paper investigates the possible impacts of air travel restrictions on the least developed countries (LDCs) and non-LDCs by examining global tourism. The impacts on LDCs are found to be ‘neutral’ on average, with both losses and gains in tourist arrivals. The extent of any losses does not appear to be beyond the scope of possible economic compensation.