造船企业运用供需链目标成本管理的探索

针对我国目前造船企业目标成本管理中存在的问题,提出将目标成本管理拓展到整个造船供需链,运用基于供需链的目标成本管理来解决我国造船成本不断上升的问题,给出了造船供需链目标成本管理的实施方案.     

Optimal housing supply in a bid-rent equilibrium framework

In this study, we examine how the spatial distribution of housing supply impacts people’s residential choices and developers’ profitability. By optimally providing housing supply in a region, developers attempt to maximize their profits; on the other hand, if residents were given a chance to decide on housing supply, what patterns of housing supply they would prefer in order to maximize their consumer surpluses. This paper studies the interplay between these two perspectives. A nested multinomial-logit choice structure that encapsulates the bid-rent process is used to capture residents’ location and travel choices simultaneously, and the resultant rents at different locations. To investigate the optimal housing supply for these two stakeholders, we conduct sensitivity analyzes to explore the impact of different housing supply patterns on total rental profit and total consumer surplus. Specifically, analytical results are derived for a simple linear network with two residential locations and one destination under homogeneous and heterogeneous value(s) of time. The results of the sensitivity analyzes indicate that segregation of housing supplies at different locations for different income classes is, surprisingly, a “preferred” outcome by residents under consumer surplus maximization, whereas creating housing supply shortages at convenient locations is a natural outcome under housing profit maximization. These results provide insights on revealing the differences and tradeoffs in performance between these two different perspectives, and on where land use regulations may be needed to balance these two objectives.     

The capitalization of subway access in home value: A repeat-rentals model with supply constraints in Beijing

Urban rail transit enhances accessibility of the communities it serves and often contributes to the value of local real properties. A small number of studies have gone beyond the traditional cross-sectional hedonic analysis to use repeat-sales data in the US for more robust estimation of rail transit’s impact on property value. While the empirical literature generally supports the positive capitalization of rail transit in home value, it has produced widely varied estimates and failed to incorporate the theoretical insight that more elastic housing supply would reduce the extent of local amenities’ capitalization in home value. Observing Beijing’s rapid expansion of subway lines during the late 2000s, this study uses repeat rental transactions from 2005 to 2011 to investigate how home value reacts to the change in the home’s distance to nearest subway station. Repeat-rentals estimates suggest a rent-distance elasticity of −0.02, 70% below the cross-sectional hedonic estimate. Moreover, using the unique history of state-owned enterprise relocations as instrument for intra-city variation in land supply, we find that the capitalization of subway proximity in home value is weaker where land supply is more elastic. Our findings support the significant bias caused by omitted variables in the hedonic estimates and confirm housing supply’s role in explaining the intra-city spatial variation in estimates.     

公平理论参考下的供应链契约

以一个考虑公平关切行为的两级供应链Stackelberg博弈模型为研究对象,且零售商、供应商都是公平关切.文中以公平理论为参考下设置公平关切决策参考点,并在此基础上构建了考虑公平关切的效用函数,并研究了零售商在公平关切行为下对供应链最优决策和供应链协调的影响.研究表明:零售商的最优订货量随着供应商批发价格的增加而减少;零售商的最优订货量随其公平关切系数的增加而减少;在批发价格契约下,供应链不能达到系统最优,但是引进保险契约可以使供应链双方达到Pareto最优.最后通过算例分析对结论进行了验证.     

《消防给水及消火栓系统技术规范》在地下车站适用性研究

对《消防给水及消火栓系统技术规范》及《地铁设计规范》中地下车站室外消防给水系统设计、室外消火栓及消防泵房设置等相关条款进行对比，分析地铁工程室外消防给水系统消防用水量取值标准、室外消火栓设置位置及数量、消防泵房设置位置等方面按《消防给水及消火栓系统技术规范》的要求进行设计在工程实施上存在的难度。列举国内各地轨道交通单水源条件下室外消火栓给水系统在室外消防水池、消防泵组及市政消火栓设置方面采取的多种组合设计方案，同时以中南某城市轨道交通为例，对不同的设计方案进行技术经济比较分析。通过对轨道交通消防给水系统既有设计方案的总结分析，提出轨道交通消火栓系统设计应根据地铁工程特点，结合消防实际救援，采取最优设计方案。     

Point queue models: A unified approach

In transportation and other types of facilities, various queues arise when the demands of service are higher than the supplies, and many point and fluid queue models have been proposed to study such queueing systems. However, there has been no unified approach to deriving such models, analyzing their relationships and properties, and extending them for networks. In this paper, we derive point queue models as limits of two link-based queueing model: the link transmission model and a link queue model. With two definitions for demand and supply of a point queue, we present four point queue models, four approximate models, and their discrete versions. We discuss the properties of these models, including equivalence, well-definedness, smoothness, and queue spillback, both analytically and with numerical examples. We then analytically solve Vickrey’s point queue model and stationary states in various models. We demonstrate that all existing point and fluid queue models in the literature are special cases of those derived from the link-based queueing models. Such a unified approach leads to systematic methods for studying the queueing process at a point facility and will also be helpful for studies on stochastic queues as well as networks of queues.     

Estimation of cost and CO2 emissions with a sustainable cross-border supply chain in the automobile industry: A case study of Thailand and neighboring countries

CO₂ emissions are increasing because of the growth in the cross-border supply chain, which is leading the locations of assembly plants and suppliers to spread across a wider area. Given that one passenger vehicle needs more than 20,000 components and parts, the automobile industry exploits the cross-border supply chain. Recently, the free cross-border movement of people, goods, capital, and information has accelerated in Asia. Therefore, a sustainable cross-border supply chain is required to reduce both CO₂ emissions and cost. This study estimates total CO₂ emissions per vehicle including production and transportation processes in Thailand and neighboring countries and the change in CO₂ emissions based on future policy scenarios that consider the automobile market and locational conditions in 2030. The results show that locating production close to the place of consumption and the electricity emissions factors in each country should be considered.     

Interplay between electricity and transport sectors – Integrating the Swiss car fleet and electricity system

Electric vehicles are seen as a future mobility option to respond to long term energy and environmental problems. The 2050 Swiss energy strategy envisages 30–75% introduction of electric cars by 2050, which is designed to support the goal of decarbonising the energy sector. While the Swiss government has decided to phase out nuclear electricity, deployment of electric cars can affect electricity supply and emission trajectories. Therefore, potential interactions between the electricity and transport sectors must be considered in assessing the future role of electric mobility. We analyse a set of scenarios using the Swiss TIMES energy system model with high temporal resolution. We generate insights into cross-sectoral trade-offs between electricity supply and electrification/decarbonisation of car fleets. E-mobility supports decarbonisation of car fleet even if electricity is supplied from large gas power plants or relatively low cost sources of imported electricity. However, domestic renewable based electricity generation is expected to be too limited to support e-mobility. Stringent abatement targets without centralised gas power plants render e-mobility less attractive, with natural gas hybrids becoming cost effective. Thus the cost effectiveness of electric mobility depends on policy decisions in the electricity sector. The substitution of fossil fuels with electricity in transport has the potential to reduce revenues from fuel taxation. Therefore it is necessary to ensure consistency between electricity sector and transport energy policies.     

基于CAN总线技术的客车起动与电源系统控制方法

阐述一种基于CAN总线技术的客车起动与电源系统及其控制方法,通过实时采集当前车辆电源状态,在发生电压异常时进行报警,并适时切断电源进行保护,以保证整车电气系统的安全,提高驾驶员的安全意识。     

城市老居住小区交通综合治理实践——以杭州市为例

老居住小区由于存在建设标准低、停车配建缺乏、社区管理薄弱等问题,近年来引发的停车供需矛盾激化、消防救护通道受阻、动静态交通秩序混乱、公共绿地损毁严重等系列矛盾日益突出,已严重影响居民生活环境,甚至威胁到生命财产安全,成为中国各大城市社会管理的一大难题。通过对老居住小区存在问题的成因及困境分析,提出以增加停车位为抓手的交通综合治理措施,实现现有资源的系统挖掘与整合,并形成有效的治理推进机制和建立可持续运行的长效管理机制,力求在技术措施、工作机制和政策保障上实现创新突破。同时,基于杭州市开展的老居住小区交通综合治理的实践经验,以及已实施并取得较好治理效果的案例,交通综合改善措施被证明切实可行。