Vector network equilibrium problems with capacity constraints of arcs

In this paper, we study a (weak) vector equilibrium principle with capacity constraints of arcs and common arcs in some different paths. We obtain some necessary and sufficient conditions for a (weak) vector minimum cost flow. By virtue of a (weak) Δ-equilibrium principle, we also derive some necessary and sufficient conditions for a weak vector equilibrium flow.     

Do hotel REIT companies face investment constraints? A comparison with C-corporation hotel companies

This study investigates whether corporate investment by REIT hotel companies (hotel REITs hereafter) is more constrained than investment by C-corporation hotel companies (hotel C-corps hereafter). The investments of hotel REITs and hotel C-corps are examined by comparing the sensitivities of investment to cash flow and investment opportunities between the two groups. Results show that the sensitivity of investment to cash flow is positive and significantly higher for hotel REITs than for hotel C-corps, suggesting that hotel REITs are likely to experience more constraints on their corporate investment. This finding suggests that hotel firms and owners should be more cautious about electing to be a REIT if they are planning large investments in the future. In addition, this finding has policy implications; even a small reduction in the rate of mandatory dividend payouts could significantly increase hotel REITs’ corporate investments.     

再论三峡库区旅游地空间的变动与重构——对《论三峡库区旅游地空间的变动与重构》的检验与发展

文章在梳理总结现有三峡旅游地空间结构研究的基础上,以2003～ 2009年三峡旅游地15区县的国内游客数和国内旅游收入数据为基础,运用位序—规模律对空间结构的变动进行了量化研究.文章发现,三峡旅游地总体上已经从空间极化阶段向均衡阶段转变,旅游产品变化、旅游交通完善和政府主导的跨区旅游企业整合等是影响空间重构的主要因素,并还将持续发挥影响.目前三峡旅游地已经形成了以万州和宜昌(夷陵—秭归)为组织核心,东段以三峡大坝—巫山—奉节为主要旅游吸引物,长江主航道、沪蓉、沪渝高速为主要轴线的旅游空间结构,但西段旅游组团的核心由丰都转为武隆,更多地表现为重庆都市圈旅游的特点,旅游空间结构的“东西分化”趋势明显；并有沿大宁河、神农溪等跨区旅游合作轴线向神农架和恩施州南北扩张的趋势.     

Technological diversity,knowledge flow and capacity,and industrial innovation

ABSTRACT

This article examines the effect of technological diversity, knowledge flow and capacity on industrial innovation performance. We suggest that there is an inverse U-shaped relationship between technological diversity and industrial innovation performance. Moreover, knowledge flow and knowledge capacity are hypothesised as negatively moderating the effect of technological diversity on industrial innovation performance. We use negative binomial regression to test the hypotheses in a panel data of 360 industry-year cases and the findings support our prediction. Managerial implications and future research directions are discussed.     

应对高峰期客流的铁路运输组织策略研究

随着我国经济的迅猛发展,铁路客运出现了越来越多的客流高峰期。文章探讨在既有设施设备条件约束下,需要采用特殊运输组织方法解决客流高峰期问题。分析了客流高峰期的组成结构及行程原因后,提出了应对高峰期客流的运输组织策略。     

实流校准三相分离式原油产量计量装置方法的探讨

根据三相分离式原油产量计量装置的工作特点，在油井井场，设计了一种实液校准油井原油产量计量装置的流程、测试步骤及数据计算与误差处理。通过对三相分离式单井计量装置的现场实液检测，为今后对三相流计量装置的现场测试提供了一种测试方法和思路。     

原油动态计量技术在仪长管道上的应用

介绍了仪长管道原油动态交接计量的现状,探讨了原油动态计量交接中误差产生的原因,分析了流量计、原油密度、原油含水量、油品温度和压力以及其它因素引起的误差,提出了消减误差的方法及措施。     

注水站流量计在线测试方法的探讨

对胜利油田注水流量计量现状进行了调研分析,提出了用现场注水罐作标准器,对注水流量计进行在线测试的方法,解决注水流量计量不准的问题。通过现场实验和数据分析,证明了该测试方法的可行性。     

基于遗传算法的城际客运专线列车开行方案研究

分析城际客运专线列车开行方案的特点。以旅客时间消耗最小为目标，建立城际客运专线旅客列车开行方案的最小费用流模型。根据模型的特点，设计相应的遗传算法，并对遗传算法的适应值函数、算法步骤和算法复杂度进行分析。分析结果表明，该算法是一个收敛于全局最优解的近似有效算法。     

A study on X party material flow: the theory and applications

A thorough study of X party material flow (XPMF), its theory and its applications is conducted in this research. The X material flow concept is an extension of the material flow (MF) theory. To further elucidate that XPMF is one type of MF service model with PMF (party, material, flow) fractal structure and the characteristics of XPMF, we develop the three-pyramid synergetic operational model of XPMF. Through the analysis of several cases, we believe that OIR (Objective relational grade, Information sharing grade, and Resource complementary grade) is the set of order parameters that control and determine the formation of XPMF new structure and its degree of being ordered. Therefore it reveals the mechanism of XPMF formation and evolution. We also provide the principles and the methods for XPMF control.