The flow-refueling location problem for alternative-fuel vehicles

Beginning with Hodgson (Geogr.Anal.22(1990) 270), several researchers have been developing a new kind of location-allocation model for “flow capturing.” Instead of locating central facilities to serve demand at fixed points in space, their models aim to serve demand consisting of origin-destination flows along their shortest paths. This paper extends flow-capturing models to optimal location of refueling facilities for alternative-fuel (alt-fuel) vehicles, such as hydrogen fuel cells or natural gas. Existing flow-capturing models assume that if a flow passes just one facility along its path, it is covered. This assumption does not carry over to vehicle refueling because of the limited range of vehicles. For refueling, it may be necessary to stop at more than one facility in order to successfully refuel the entire path, depending on the vehicle range, the path length, and the node spacing. The Flow Refueling Location Model (FRLM) optimally locates p refueling stations on a network so as to maximize the total flow volume refueled. This paper presents a mixed-integer programming formulation for the nodes-only version of the problem, as well as an algorithm for determining all combinations of nodes that can refuel a given path. A greedy-adding approach is demonstrated to be suboptimal, and the tradeoff curve between number of facilities and flow volume refueled is shown to be nonconvex.     

Mickey Mouse and the IDioT principle for assessing research contribution: discussion of ‘Is the relationship between investment and conditional cash flow volatility ambiguous,asymmetric or both?’

Keefe and Tate ( 2013 ) provide both interesting and worthwhile insights into whether, under what circumstances and to what extent cash flow volatility impacts corporate investment. In the current paper, I have two related goals. First, more narrowly, I provide a constructively critical commentary on salient aspects of their empirical strategy, giving particular emphasis to the key drivers of Keefe and Tate's contribution to the literature. Second, illustrated in the context of Keefe and Tate, my broader goal is to give general advice especially aimed at novice researchers on how to make any empirical study more appealing to a critical reader.     

如何利用Excel编制现金流量表

在会计实务工作中,利用Excel软件编制现金流量表,既可减轻会计人员的工作量,又可提高会计工作效率,从而实现会计工作的无纸化。利用Excel编制现金流量表主要包括制作会计科目代码表单、制作现金流量项目代码表单、制作凭证表单和制作现金流量表等步骤。     

浅谈债务重组等五项会计准则的修改

财政部发布的八项具体会计准则和《企业会计制度》,其中包括债务重组等在内的五项准则,是在先前颁布的准则基础上所做的修改,这五项会计准则的修改主要是针对其在实际应用过程中出现的一系列问题所做出的。     

所有权性质、融资约束与企业投资——基于投资现金流敏感性的经验证据

本文通过研究中国制造业上市公司投资支出与其内部现金流的敏感性,分析经济转轨过程中不同所有权企业融资约束的变动情况。研究发现:(1)制造业上市公司存在明显的融资约束,且民营企业的融资约束明显高于国有企业;(2)在研究期间,全部样本企业的投资现金流敏感性随时间逐渐降低;(3)预算软约束的存在,使得国有企业投资现金流敏感性随时间下降的幅度比民营企业低。     

现金流管理研究现状评介及展望

近年来,现金流受到报表使用者的广泛关注,但现金流操控开始盛行颠覆了人们以往认为现金流不可操控的认知.学术界借助盈余管理较为成熟的研究体系去识别现金流操控现象及其动机,对会计与财务研究有较大贡献.然该研究还处于起步阶段,许多方面尚待深入,且研究方法大都脱胎于盈余管理,缺乏创新思路.学术界急需对我国现金流管理的研究方向重新思考,借此为今后提供理论支持和方向指导.     

电导传感器测量油井流量与含水率

井下油水两相流的流量和含水率在油井多参数测试中,是两个非常重要的测量参数。本文介绍了电导传感器的工作原理,并介绍了使用电导传感器测试油井中流量和含水率,并通过互相关算法对测试数据进行处理最终计算出流量的方法。     

京津冀地区城市流强度时空动态实证研究

随着科技水平的提高,交通、通讯条件的改善,城市联系愈来愈密切,并呈现出网络化特征。本文基于城市流强度理论模型,对京津冀地区13座城市5年的外向功能量、城市流强度、城市流倾向度等指标进行测算,并进行时间、空间动态比较分析,将京津冀地区集聚扩散中心划分为三个等级。针对京津冀地区城市群的功能联系现状,提出各城市应进一步加强城市间合作和交流,利用中心城市的影响力带动整个地区的发展。     

基于现金流量指标的财务危机预警模型分析

由于企业生产经营得以持续的基本条件是获得足够的现金流量,本文以现金流为主线,探讨如何准确把握现金流量指标来进行财务预警。在指标的选取上采用了时差相关分析法,筛选出财务预警所需的先行或一致性指标。最后以上市公司的财务报表为数据来源进行实证研究,证明了现金流量指标确有超前的财务危机预警功能。     

公司治理耗散性高阶有序跃迁研究

公司治理作为人类经济社会中一个开放型系统，其基本构件——各个子系统序参量变化，可不断地产生高阶有序跃迁，进而引发治理系统形成新的稳态耗散结构。其耗散机理主要表现为远离平衡状态的非线性和非稳定性，状态序参量在开放态下的变动方向、速率和跃迁水平，耗散跃迁的对称性自发破缺压分岔，微涨落的非线性放大和非平衡相变。中国公司治理必须完善其构件的开放性发挥，其交互效应形成耗散结构的高阶有序跃迁，优化结构。完善功能，达到“无为而治”的境界。