旅行社的旅游线路优化设置问题探讨

尽管在旅游线路的设计过程中需要解决的问题很多,但从优化的角度而言,如何设计出一条能实现出发地与目的地间的最短路径目标,便是其中的最为关键性的一个问题。由于不同的交通方式的不同组合能对应着不同的路程、时间与成本问题,因而,如何通过有效的选择来形成最佳的旅游线路也就有了相当的必要性。此外,在旅游线路设计与安排过程中,旅行社除了要合理安排和规划旅游线路的长度以力求不走回头路、不走冤枉路和形成有效的闭合回路外,还需充分考虑到其中的线路在时间安排上的合理问题;否则,再好的线路安排也会失去其内在的价值与影响力。     

关于产业集群技术创新的若干问题

产业集群的蓬勃发展带动了我国区域经济迅速发展,但当前我国产业集群中企业创新不足的问题日益显现,阻碍了产业集群的进一步发展,而要强化产业集群技术创新,关键是探寻技术创新的实现路径,整合创新要素,做出有利于推进产业集群技术创新的战略选择.     

政府在发展高等职业教育中的角色定位思考

高等职业教育是我国高等教育的有机组成部分,政府在发展高等职业教育培训中拥有无可争议的地位,但政府能否对自己的角色加以理性定位却事关高职教育的健康发展。依据中国的具体国情,本文提出政府在高职教育发展中应该扮演催化剂、支持者、激励者和调控者的理性角色。     

Generalized piecewise linear histograms

We extend the concept of piecewise linear histogram introduced recently by Beirlant, Berlinet and Györfi. The disadvantage of that histogram is that in many models it takes on negative values with probability close to 1. We show that for a wide set of models, the extended class of estimates contains a bona fide density with probability tending to 1 as the sample size n increases to infinity. The mean integrated absolute error in the extended class of estimators decreases with the same rate n^–2/5 as in the original narrower class.     

On the measurement of corporate diversification strategy: Evidence from large U.S. service firms

Actual, not potential, relatedness determines the results of diversification strategies. An external examination of a firm's businesses, products, markets and technologies permits an assessment of potential relatedness among its various businesses. Potential relatedness is, however, often not realized. Also, relatedness may be externally invisible. Hence, actual relatedness may diverge from externally measured potential relatedness. This paper provides evidence suggesting that measures of corporate diversification strategy based on internal data differ significantly from those based on externally available data.     

The adequacy of asymptotic approximations in the near-integrated autoregressive model with dependent errors

We consider the normalized least squares estimator of the parameter in a nearly integrated first-order autoregressive model with dependent errors. In a first step we consider its asymptotic distribution as well as asymptotic expansion up to order O_p(T⁻¹). We derive a limiting moment generating function which enables us to calculate various distributional quantities by numerical integration. A simulation study is performed to assess the adequacy of the asymptotic distribution when the errors are correlated. We focus our attention on two leading cases: MA(1) errors and AR(1) errors. The asymptotic approximations are shown to be inadequate as the MA root gets close to −1 and as the AR root approaches either −1 or 1. Our theoretical analysis helps to explain and understand the simulation results of Schwert (1989) and DeJong, Nankervis, Savin, and Whiteman (1992) concerning the size and power of Phillips and Perron's (1988) unit root test. A companion paper, Nabeya and Perron (1994), presents alternative asymptotic frameworks in the cases where the usual asymptotic distribution fails to provide an adequate approximation to the finite-sample distribution.     

现代企业财务风险的测定和防范

在市场竞争环境下，现代企业面临的各种风险不断增多，财务风险作为企业特有的风险日益突出，是企业利用融资财务杠杆的直接后果，企业必须重视财务风险的测定和防范，以增强企业财务实力。     

当前我国经济形势与金融对策

本文从GDP、物价、就业问题以及国际收支方面分析了今年国内宏观经济形势:总体上运行情况良好,但局部依然存在各种问题和困难。金融业作为服务部门,是现代经济的核心。本文着重从金融业改革的角度,按照科学的可持续发展观点,提出了几点对策,其中涉及到优化资源配置,维护金融稳定,深化金融改革,改进金融服务,推进信用建设等。