绿色货运发展的问题与对策研究

发展绿色货运对促进货运行业节能减排,提高运输效率具有十分重要的意义。本文首先介绍了绿色货运产生的背景,接着阐述了绿色货运的内涵,然后探讨了我国发展绿色货运中存在的主要问题,最后提出了发展绿色货运的对策与建议。     

Optimal route decision with a geometric ground-airborne hybrid model under weather uncertainty

Adverse weather is the dominant cause of delays in the National Airspace System (NAS). Since the future weather condition is only predictable with a certain degree of accuracy, managing traffic in the weather-affected airspace is a challenging task. In this paper, we propose a geometric model to generate an optimal combination of ground delay and route choice to hedge against weather risk. The geometric recourse model (GRM) is a strategic Probabilistic Air Traffic Management (PATM) model that generates optimal route choice, incorporating route hedging and en-route recourse to respond to weather change: hedged routes are routes other than the nominal or the detour one, and recourse occurs when the weather restricted airspace becomes flyable and aircraft are re-routed to fly direct to the destination. Among several variations of the GRM, we focus on the hybrid Dual Recourse Model (DRM), which allows ground delay as well as route hedging and recourses, when the weather clearance time follows a uniform distribution. The formulation of the hybrid DRM involves two decision variables - ground delay and route choice - and four parameters: storm location, storm size, maximum storm duration time, and ground-airborne cost ratio. The objective function has two components: expected total ground delay cost and expected total airborne cost. We propose a solution algorithm that guarantees to find the global optimum of the hybrid-DRM. Based on the numerical analysis, we find that ground-holding is effective only when combined with the nominal route. Otherwise, it is optimal to fly on the route determined by the DRM without ground delay. We also find the formula of the threshold ground-airborne cost ratio, which we call the Critical Cost Ratio (CCR), that determines the efficacy of ground delay: the higher the CCR, the more effective the strategies involving ground delay. We conclude that both ground delay and route hedging should be considered together to produce the best ATM decisions.     

对绿色建筑的几点思考

绿色建筑是指在建筑的全寿命周期内,最大限度地节约资源,保护环境和减少污染,为人们提供健康的使用空间,与自然和谐共生的建筑。其具体的概念是在建筑全生命周期中平衡建筑环境的性能及人们对资源的消耗,对环境的影响。在该前提下创建的建筑空间能够使人们可高效、健康地工作和生活。     

瑞士R&D经费投入分析

R&D经费投入是评价一个国家科技发展水平和科技实力的重要指标,也是衡量一个国家创新能力和水平的重要尺度。文章对瑞士R&D经费投入规模及强度(R&D/GDP)进行了深入的分析研究。     

无锡市自主创新的发展现状和问题

自主创新是实现无锡可持续发展的重要战略,也是无锡建设"国家战略与地方特色相互交融的创新型城市"的客观要求.本文介绍了无锡市自主创新发展的现状,同时也分析了目前所面临的主要问题,认为在政府科技投入、研发人员数量以及发明专利数量方面与其他城市相比还存在较大的差距.     

Quality management,environmental management maturity,green supply chain practices and green performance of Brazilian companies with ISO 14001 certification: Direct and indirect effects

This study aims to test a new conceptual model based on the relationship between quality management (QM), environmental management maturity (EMM), adoption of external practices of green supply chain management (GSCM) (green purchasing and collaboration with customers) and green performance (GP) with data from 95 Brazilian firms with ISO 14001. To our knowledge, such links and relationships are not simultaneously identified and tested in the literature. The results indicate the validation of all of the research hypotheses. This paper highlights that an improvement in green performance will require attention to quality management, environmental management maturity, and green supply chain.     

Changes of Thai economy since 19701 1

Within the last 30 years, the number of Thai population increased from 35 million to 62 million, the general price level went up 6 times, and Thai currency baht devaluated 2.2 times against the dollar. The industrial production increased 36 times nominally. The biggest industry of Thailand changed from agriculture to manufacture, and the total value of exports jumped by 192 times and that of imports grew by 95 times. Thai current account balance had recorded a deficit every year from 1970 to 1996. During the same period of time, however, the capital account balance had shown surplus. The inflow of foreign capital was the only stronghold of Thai economy at that time. In 1997, Thailand suddenly experienced a total change of its external environment From then on, Thai current account shifted from a deficit to a surplus and Thai capital account turned from a surplus to a deficit. The conclusion of this paper indicates that the future of Thai economy is heavily dependent on whether the amount of surplus in Thai current account could surpass the deficit in Thai capital account     

影响我国税收收入因素的实证分析

税收是我国财政收入的重要组成部分,对维持社会稳定和促进经济增长有很大的作用。影响税收收入的因素来自于很多方面,从国内生产总值,财政支出和物价这三个方面进行研究,得出税收与三者的关系,为现行政策提供参考。     

山西财政运行特点、存在问题及对策

2001年1-10月，山西宏观经济保持了持续，稳定增长的发展态势，财政收入大幅度增长，并高于GDP的增长速度，收支规模趋于合理，呈现出四大特点，但同时由于经济基础薄弱，自然条件较差等因素。存在着不容忽视的问题。因此，必须采取相应的对策。     

对绿色GDP核算的几点思考

本文指出现行GDP的缺陷,论述了绿色GDP的必要性,并对当前一些绿色GDP核算尝试性的方法进行分析,提出在绿色GDP核算中,固定资产折旧部分不是当期新创造的价值,要给予扣除。并对绿色GDP核算中存在的难点进行了探讨。