公路建设项目经济评价方法及应用

公路建设项目经济评价是可行性研究的重要内容，旨在评价拟建项目的经济合理性和可行性，为投资决策和方案比选提供依据。以北方某公路工程可行性研究中经济评价为实例，分析研究目前公路建设项目经济评价内容和方法。     

Working Less and Bargain Hunting More: Macroimplications of Sales during Japan's Lost Decades

Standard New Keynesian models have often neglected temporary sales. In this study, we ask whether this treatment is appropriate. We use Japanese scanner data covering the last two decades and find a negative correlation between the frequency of sales and hours worked. We then construct a model that takes households' decisions regarding their allocation of time for work, leisure, and bargain hunting into account. We show that the decline in hours worked explains the rise in the frequency of sales. The real effect of monetary policy shocks weakens by around 40% due to temporary sales, but monetary policy still matters.     

Optimal pair-trading strategy over long/short/square positions—empirical study

Suzuki [Automatica, 2016, 67, 33–45] solves the optimal, finitely iterative, three-regime switching problem for investing in a mean-reverting asset that follows an Ornstein–Uhlenbeck price process and find explicit solutions. The remarkable feature of this model is that the investor can explicitly take either a long, short or square position and can switch the position, with transaction costs, during the investment period. We run empirical simulations of such multiple-regime switching models. There are very few such attempts in the existing literature because it is difficult to find, first, an explicit solution to the problem and second, appropriate financial assets that follow the artificial stochastic process required by the mathematical model. According to the Monte Carlo simulations of the optimal pair-trading strategy, the mean daily Sharp ratio is more than 2.3, whereas the mean Sharp ratio for the historical simulation of the ‘stub’ pairs (combinations of parent/subsidiary companies) is 0.6886. We believe that the results obtained from performing the empirical simulations are remarkable and consider that the optimal switching strategy of the rigorous mathematical model is applicable to businesses in the real world. For the reference many pseudo-program codes are added, which can help to replicate the optimal trading strategies.     

Sharing my way to success: A case study on developing entrepreneurial ventures using social capital in an OSS community

While Open Source Software (OSS) communities provide opportunities for knowledge creation, we have a limited understanding of how entrepreneurs leverage OSS communities for their entrepreneurial ventures. Using social capital theory in a mixed methods case study, we compare entrepreneur and non-entrepreneur behaviors to investigate how entrepreneurs build social capital within an OSS community. This study shows that entrepreneurs differentiate themselves from non-entrepreneurs by focusing on cognitive and relational capital building activities, which in return makes it possible for them to leverage their social capital to influence and shape the environment in which they are operating. Our findings suggest that entrepreneurs strategically select which activities within the community to expend their limited resources on (e.g., developing code over participating in email conversations) and build their social capital more through their actions than through their words (e.g., showing their commitment to the community through code commits, bug fixes, and documentation). Given the liabilities of newness and smallness as well as other challenges faced by entrepreneurs, applying an open innovation strategy in OSS communities could be one approach where entrepreneurs, by developing and freely revealing their intellectual property to the community, share their way to success via OSS-infused entrepreneurial business ventures.     

基于主成分与聚类分析法的城市土地利用规划分区研究——以广州市为例

[目的]土地利用分区是土地利用总体规划的核心内容之一,是合理确定土地利用方向,优化土地利用结构与布局的重要途径。为了对广州市土地利用及未来发展方向提供理论指导,结合其土地利用现状和特点,选取土地利用结构、土地开发利用程度、社会经济状况和环境资源承载力4项一级指标及15项二级指标,建立土地利用综合分区指标体系。[方法]通过SPSS19.0软件,运用主成分分析法提取出前4个主成分,并将其作为新的样本数据,采用层次聚类分析法对广州市土地利用进行综合分区。[结果]根据聚类分区结果,将广州市分为4类土地利用区:中心发达区,包括荔湾区、海珠区、天河区和越秀区;综合发展区,包括白云区、番禺区、花都区、增城区和从化区;重点潜力区即南沙区;资源组合区是(新)黄埔区。根据各分区的差异性,提出各区域土地资源开发利用中存在的主要问题及未来发展方向。[结论]根据各区的自然经济条件及土地利用状况,将广州市分为4类土地利用区具有合理性,能为广州市今后土地利用规划的科学编制提供参考。     

近10年崇州市土地利用变化基本特征与空间格局

[目的]土地利用变化研究是揭示土地利用对人类活动响应程度的重要途径,通过对其变化特征及空间格局的研究讨论人地关系在不同地域空间上的强度与作用模式。[方法]基于2002年、2014年TM/ETM+影像,在RS和GIS技术的支持下,采用人机交互图像处理方法提取了崇州市土地利用信息,应用土地利用动态度、土地利用程度、空间转移图谱、城市扩展指数、缓冲分析模型和方法对崇州市近10年来土地利用变化时空特征进行了研究。[结果](1)土地利用类型以林地、耕地、建设用地为主,建设用地动态度最大达到5.72;整体土地利用程度由254.25增长到260.93,各乡镇变动值差异较大。(2)土地空间转换面积达1.850 85万hm~2,占研究区总面积的16.94%;增长面积最大的图谱单元依次是新增建设用地、新增耕地和新增林地;建设用地、耕地、水体与高程、坡度之间负相关性显著,坡度0°~6°是人类活动最频繁的区域。(3)中心城区建设用地面积大幅增长,缓冲范围内建设用地面积增加了2 120.76hm~2,城市中心自河流向东、东南、东北3个方向扩展。[结论]崇州市土地利用整体处于快速发展时期,地域差异明显,受人类活动影响显著。     

基于能量分析的农业生态可持续发展指数方法研究

[目的]农业可持续发展的研究首先面临的一个问题是如何对其进行有效评价,农业可持续发展评价一般采用多指标评价法,然而过多的指标给实际操作带来很多困难。文章从可持续发展评价理论创新和方法创新的需求出发,寻求建立一个简便易行的综合性指标——农业可持续发展指数(ASDI),以提高农业可持续发展评价的有效应和准确性。[方法]该文基于能量投入产出方法,利用Logistic曲线构建了ASDI,并以贵州省印江县为实证研究案例,对其农业生态的可持续性行进行评价分析。[结果]通过研究发现印江县的ASDI具有很大波动性,由于2002~2007年农业投入增加,印江县的ASDI呈现下降趋势,其中2007年因为投入过多而出现了负效应指数。[结论](1)利用一个简单的综合指标来评价农业可持续发展在理论和实践上是可行的;(2)ASDI作为农业可持续发展的研究,或将为生态安全预警提供了一个可供参考的指标。     

基于DEA模型的山东省农地利用经济效益分析

山东省农地面积较广,利用类型丰富,农地的合理利用对推进山东省农业经济发展及土地资源的可持续发展具有重要意义。文章阐述了山东省农地利用状况,从自然因素、土地投入、农业土地利用结构、农业从业人员素质、农产品市场意识及经营手段等方面探讨影响农地利用经济效益的因素,通过构建DEA模型,对农地利用经济效益进行应用分析,并提出加大农业用地投入和建设、优化农业用地结构和规模、强化市场经营意识和管理等提高山东省农地利用经济效益的对策建议,以期为山东省土地合理规划利用提供理论依据。     

城乡一体化进程中乡村土地利用效益评价

文章在实地(河北省邢台市)调研基础上,通过文献分析与成本分析相结合的方法对城乡一体化进程当中乡村土地利用效益进行系统的评价,并在此基础上揭示出目前我国在城乡一体化进程当中乡村土地利用过程当中存在的问题,并给予相应的建议。研究结果表明:我国城乡一体化进程当中,对我国乡村土地利用效益影响较大的主要因素有政府政策不合理、对于土地利用效益缺乏足够认识,这些原因直接导致在城乡一体化进程当中乡村土地耕地边际化现象严重、城市建设用地规模过大、土地生态效益低下及乡村土地配置不合理等现象的出现。基于对土地效益评价与我国目前乡村土地利用状况的深入分析,该文认为应从土地的经济效益、社会效益及生态效益对于目前城乡一体化进程当中存在的土地利用效益偏低的现象进行整改,例如提高土地的集约度,实行大规模的机械化生产进而提高土地的经济效益;通过合理规划商业用地、居民住房用地及农业用地的比例提高土地的社会效益;发展多种形式的生态养殖与特色旅游业促进土地生态效益的提高。