Transport Costs in the Automotive Supply Chain

The study, carried out within the LogNet research project financed by Calabria region, deals with the analysis of the automotive supply chain. In particular, after a first examination of the characteristics of the whole automotive supply chain, attention was focussed on its final part, that is, on transport and end-market distribution. The paper proposes specific models, which are differentiated by the transport mode （road, rail, sea） they are involved, to estimate the temporal and monetary costs related to the activity of goods distribution to the compounds/end-clients. The proposed mode/ling formulations concern two different areas of investigation： the network segment and interchange nodes. Each cost item is also calculated through aggregate formulations （where the cost is function of a single significant variable in relation to a unit cost parameter） and disaggregate formulations （where each cost item is separately considered）. The models have been applied to a study carried out for the modal transfer of vehicles in the port of Gioia Tauro, south of Italy. The analysis has allowed, on the one hand, to calibrate certain models and, on the other, to simulate certain scenario hypotheses to verify the technical feasibility of a different structure for the automotive supply chain in Italy.

Optimizing a Transportation System Using Metaheuristics Approaches (EGD/GA/ACO): A Forest Vehicle Routing Case Study

The large-scale optimization problem requires some optimization techniques, and the Metaheuristics approach is highly useful for solving difficult optimization problems in practice. The purpose of the research is to optimize the transportation system with the help of this approach. We selected forest vehicle routing data as the case study to minimize the total cost and the distance of the forest transportation system. Matlab software helps us find the best solution for this case by applying three algorithms of Metaheuristics: Genetic Algorithm (GA), Ant Colony Optimization (ACO), and Extended Great Deluge (EGD). The results show that GA, compared to ACO and EGD, provides the best solution for the cost and the length of our case study. EGD is the second preferred approach, and ACO offers the last solution.

TRANSPORT COSTS AND CHINA'S EXPORTS:SOME EMPIRICAL EVIDENCES

Based on a new panel data set covering exports of four Chinese port cities to 32 countries and Hong Kong over the period of 1997-2008, this paper extends the conventional gravity model to assess the impacts of transport costs and port efficiency on China＇s exports. The results can be summarized as three main findings： （1） The improvements of port efficiency and reduction of road transport costs play a vital role in China＇s export competitiveness in the global market. The coefficient estimates on them are relatively large, around 0.72 and -0.89, respectively; （2） The effect of transport costs and port efficiency on China-to-Asia exports significantly exceeds that on China-to-Europe and China-to-America exports; （3） The overall estimated elasticity of road, railroad and port measure is 1.66, which is almost three times that of the average wage of port cities. The empirical results provide strong evidences that upgrading China＇s transport service networks should offer greater scope for maintaining and increasing its competitive edge in low cost productions. The findings offer some insights and priorities for government policy making.

A Study on Transport Costs and China＇s Exports： An Extended Gravity Model

This paper suggests an extending conventional gravity model design to empirically analyze the effect of transport costs and port efficiency on China's export flows. It shows that factor endowment and transport costs variables affect export trade value in directions that New Trade Theory(NTT) predicted. Also, the evidence indicates that, controlling for the effects of transport costs on trade, variables in traditional gravity model are consistent with previous empirical studies in both magnitudes and directions. Moreover, more than 22% of the variation in Chinese export trade can be explained by those three variables alone. The findings reported in this paper empirically explains how seriously transport costs and port efficiency affect China's export growth by comparing effects of labour production factor costs on external trade. It suggests that the improvement of port efficiency and reduction of road transport costs play a vital role in China's export competitiveness in the global market.

Composite Sustainable Indicators Framework for Cost Assessment of Land Transport Mode in Lebanon Cities

The aim of the work performed in this paper is to present a composite indicators framework to guide sustainable transportation planning in Lebanon by assessing the sustainability marginal cost of Land Transport modes used mostly based on ICE (internal combustion engine) auto dependence. The framework covers 6 indicators of the triple bottom line of sustainability (economy, society, and environment): operating cost, energy consumption, noise exposure, congestion delay, emissions, and safety. The framework process follows an evaluation toolkit that monitors the cost implied from listed individual indicators of transport mode. Moreover, this evaluation methodology can be used to estimate to an acceptable degree the cost variation resulting from transport mode modifications within same geographical zone. This cost variance is the main interest of investors and decision makers seeking profits and successful results of their transportation planning process. A case study is executed in Lebanon GBA (Greater Beirut Area), where the annual cost of an alternative consisting of light rail transit (LRT) to passenger cars (PC) system is assessed;applying the stated methodology. Results show clearly an environmental amelioration with a reduction of 4,651,817,100 MJ of energy and 181,936 ton of CO2 emissions in addition to a saving of 255,643,035$ annually.

Study on Rural Solid Waste Collection and Transportation Mode and Route Optimization Strategy in the Cold Regions of Northern China

Rural vitalization is a major strategy for reform and development of agriculture and rural areas in China,the key task of which is improving rural living environment.Imperfect rural solid waste(RSW)collection and transportation system exacerbates the pollution of RSW to rural living environment,while it has not been established and improved in the cold region of Northern China due to climate and economy.Through the analysis of the current situation of RSW source separation,collection,transportation and disposal in China,an RSW collection and transportation system suitable for the northern cold region was developed.Considering the low winter temperature in the northern cold region,different requirements for RSW collection,transportation and terminal disposal,scattered source points and single terminal disposal nodes in rural areas,the study focused on determining the number and location of transfer stations,established a model for transfer stations selection and RSW collection and transportation routes optimization for RSW collection and transportation system,and proposed the elite retention particle swarm optimization–genetic algorithm(ERPSO–GA).The rural area of Baiquan County was taken as a representative case,the collection and transportation scheme of which was given,and the feasibility of the scheme was clarified by simulation experiment.

Study on the Transportation Problem of Petrol Secondary Distribution with Considering Shortage Cost

Petrol is a kind of strategic natural resources. Provide legitimate transportation plans for the petrol secondary distribution are the key links to guarantee the petrol provision. If the total supply is insufficient, some petrol stations can’t avoid shortage because their demands could not be met. So the shortage cost will appear. This paper studies the problem of how to arrange the transportation plan in order to minimize the total cost when the total volume of supply is insufficient. Given the storage volume, the sales rate and the unit shortage cost of every petrol station, considering the full loading constraints of the compartment vehicle, a mixed integer programming model for minimizing the total cost of petrol secondary distribution is established. A Lingo program is compiled for solving the model. Finally, simulation on an example has been done and a reasonable transportation plan is obtained. The model and algorithm in this paper can provide a theoretical basis for dispatching department to make transportation plan.

Minimum Cost of Capacity Expansion for Time-Limited Transportation Problem On-Demand

The minimum cost of capacity expansion for time-limited transportation problem on-demand (MCCETLTPD) is to find such a practicable capacity expansion transportation scheme satisfying the time-limited T along with all origins’ supply and all destinations’ demands as well as the expanding cost is minimum. Actually, MCCETLTPD is a balance transportation problem and a variant problem of minimum cost maximum flow problem. In this paper, by creating a mathematical model and constructing a network with lower and upper arc capacities, MCCETLTPD is transformed into searching feasible flow in the constructed network, and consequently, an algorithm MCCETLTPD-A is developed as MCCETLTPD’s solution method basing minimum cost maximum flow algorithm. Computational study validates that the MCCETLTPD-A algorithm is an efficient approach to solving the MCCETLTPD.

考虑实质性降本的物流成本评价指标及相关对策建议

为科学评判物流成本,提升物流成本评价指标的系统性、全面性,首先,对物流成本、宏观物流成本的概念进行辨析,通过国内外对比、实地调研等方法,深入分析我国物流成本构成、物流发展阶段与水平,并从产业结构、平均运距、运输结构三方面探讨宏观物流成本影响因素;然后,提出单位货物运输周转量支撑GDP产出值、单位货物运输周转量物流成本、物流费用增速与GDP增速之比(或之差)、社会物流总费用占社会物流总额比重等物流成本评价补充指标,从不同维度弥补了“社会物流总费用与GDP的比率”作为物流成本单一宏观评价指标的局限性;最后,基于实质性降本视角,分析制约物流成本的深层原因,并从降低多式联运成本,优化运输组织,加快发展物流领域新质生产力,实现精益化仓储管理,提升供应链一体化管理水平等方面,提出降低物流成本的对策建议。

拥堵收费下考虑船主心理期望成本的过坝策略研究

本文针对内河航运中水利枢纽通航拥堵问题,在拥堵收费下引入心理期望成本,以探寻面向双过坝模式(通航建筑物过坝和翻坝转运)的优化策略。首先,应用非抢占式M/M/1排队系统,构建了以综合过坝成本为参考点的决策模型,提出了三种情形(无心理期望成本、通航建筑物过坝的心理期望成本、双过坝模式的心理期望成本)下的船舶过坝优化策略,并对比分析了通航建筑物过坝比率、船舶平均等待时间和过坝系统总成本;然后,引入对翻坝转运的补贴策略,通过调整心理期望成本水平,来影响船舶过坝策略选择;最后,以三峡工程为例,验证了上述模型的有效性。结果表明:在拥堵收费下,考虑船主心理期望成本,可以促进过坝方式的转移,降低船舶过坝平均等待时间,且双过坝模式中均考虑该因素更有利于提升通航效率;同时,实施翻坝转运补贴策略,能充分发挥心理期望成本的调节作用,从而有效缓解水利枢纽通航拥堵问题。

依托湘桂运河的湖南省工程机械出口运费分析

运输费用分析是工程机械选择何种运输方式的重要决策依据。文章以三一重工的产品和运输需求为例,从运输方式的角度对工程机械进行分类,总结了公路运输和水路运输2种方式下工程机械运费的计算方法,根据湖南省货物运输市场的有关调研数据,对典型工程机械产品的运输费用进行了计算,对依托湘桂运河的新物流通道和现有物流通道2种物流通道的运费成本进行了比较分析。在此基础上,验证了水路滚装运输方式的可行性。研究为湖南省工程机械开展水路滚装运输提供了经济性分析参考,同时为湖南省内河航运绿色发展提供了新思路。

基于深度强化学习的农村物流运输路径自动选择研究

常规方法求解运输路径自动选择模型时,选择的运输路径的运输总成本较高,因此,提出基于深度强化学习的农村物流运输路径自动选择方法。通过分析农村流通供应链的特殊性确定目标函数,并基于目标函数设计运输路径自动选择模型,采用深度强化学习算法求解,设置状态-动作空间、奖励函数等要素完善动作选择过程,输出模型最优解,从而实现运输路径自动选择的目的。在实验论证中,所提方法所选运输路径的平均运输成本为8.35万元,相比对照方法更低。结果表明,设计的方法能够有效规划物流运输路径,降低运输成本。

城市交通拥堵组合治理政策仿真研究

为探究不同交通拥堵治理政策的作用与效果,从交通发展战略、交通需求管理、交通费用调节3个方面设计了16种政策模拟情形,通过Vensim PLE软件进行仿真模拟。结果表明,交通需求管理是治理交通拥堵最有效的方式,其次是交通发展战略和交通费用调节,该实验结果为城市交通优化提供了有益参考。未来治理城市交通拥堵时,应注重调节交通需求和供给之间的矛盾,综合运用土地规划、交通管理等手段,科学控制交通需求总量、出行方式和时空分布,以实现供需在不同阶段和层次上的相对平衡,从而确保城市交通系统的可持续发展。

交通设施改善、市场集聚效应与城市人口增长差异

针对中国城市人口增长率和城市规模明显分化的现象,本文从向心力的集聚效应和离心力的通勤成本视角进行研究。理论模型和1990—2020年全国人口普查数据的回归结果显示,地铁等交通设施改善和基于市场潜力的消费集聚效应会增大均衡时城市规模,区位基础等本地特征因素也会影响均衡城市规模。稳健性和异质性检验表明,交通设施的改善驱动高等级大城市人口的持续增长,来自市场潜力的集聚效应是中小城市人口增长的关键因素。进一步分解关键解释变量的计量结果表明,城市群,特别是都市圈的中小城市的人口快速增长得益于圈层结构中市场潜力带来的集聚效应,而内陆和东北的孤立中小城市因市场潜力弱而人口增长缓慢。机制分析结果显示,市场潜力通过增加产品需求和提升工资水平、交通设施改善通过提高有效劳动力数量和提升公共服务水平,吸引人口流入并推动人口增长,且房价调节关键解释变量与人口增长的关系。为促进城镇体系协调发展,国家应构建“中心城市-都市圈-城市群+外围中小城市”多层次空间格局,优化区域空间功能分工体系。

考虑鲁棒成本与绝对后悔的最短路径问题研究

为克服鲁棒偏差方法在处理区间路网时所求鲁棒最短路径的保守性问题,通过分析鲁棒成本的定义以及鲁棒最短路径过于保守的原因,结合算例分析提出了绝对后悔值的概念,并以鲁棒成本和绝对后悔值为目标函数建立了区间路网的多目标最短路径模型;根据最短路径模型的特点设计了分离路径决策变量与连续变量的Benders分解算法,同时基于传统有效路径的判断依据重新定义了符合该最短路径模型的有效路径,并在分解后的主问题模型中引入了有效路径约束以加快算法收敛速度;利用MATLAB生成了一个包含29个节点、70条双向通行路段的区间路网对模型与算法进行仿真测试。结果表明:考虑鲁棒成本和绝对后悔值的最短路径模型能在区间路网中找到不保守,且同时兼具鲁棒性的最短路径,能够有效克服鲁棒偏差方法的缺陷。

基于需求层次理论的城市公共交通发展战略研究

针对目前城市交通供需结构不平衡的问题,以马斯洛需求层次理论模型为参考,结合城市交通需求和供给特性,分析其供求关系及层次结构,提出城市交通供需的响应关系和理想化城市交通出行结构。考虑时间、经济、舒适度等交通需求因素和环境、运营、基础设施、能耗等交通供给资源,以现状需求、资源、环境污染、运营、发展规模、时间为约束,从宏观和微观两个角度构建双层规划模型。以大连市为研究对象,基于现有交通出行结构开展成本分析,计算现有出行需求情况下,大连市城市交通结构的适宜比例,并将计算结果与现有出行结构进行比较。研究表明,优化的出行结构可以更好地满足现有城市交通的出行需求,满足城市交通可持续发展的目标,研究结果可为今后大连市公共交通发展提供参考。

数字经济发展对产业链供应链韧性的影响研究

在全球化深入发展与大国竞争加剧的背景下,强化产业链供应链韧性成为各国必须直面的重要议题。文章深入探讨了产业链供应链韧性的核心要素及其作用机制,主要从供需匹配度、稳定性以及供应质量提升三个维度进行了理论剖析。基于上市公司数据检验了数字经济发展对产业链供应链韧性的实际影响。结果显示,数字经济的迅猛发展显著提升了供需匹配的精确度、实现了稳定性的增强以及供应质量的优化,从而有效增强了产业链供应链的韧性。这一结果经过多种稳健性处理后依然成立。此外,文章研究还发现,数字经济的发展对大规模供应商、国有供应商以及市场化程度较高地区的企业产业链供应链韧性提升作用更大。最后,机制检验表明,数字经济发展主要通过减少企业沟通协调与库存运输成本实现产业链供应链韧性的升级。

动态环境下基于换电模式的电动车路径问题研究

在实际配送中,考虑车速受不同天气、不同时段的影响,根据电动车辆行驶速度与能耗之间的函数关系,以电动车固定行驶成本、能耗成本、时间惩罚成本构成的总运输费用最小为目标,以车辆载重、车辆电池容量、客户时间窗、车辆速度为约束条件,构建动态环境下基于换电模式和时变速度的电动汽车路径优化模型。用遗传算法对模型求解,采用实数编码、轮盘赌选择算子、随机单点交叉、随机变异的方式,并以小变异率提高局部搜索能力,然后与车辆速度恒定时的几种情况进行对比。试验结果表明,所建立的优化模型更符合实际情况,能够根据客户属性和动态环境下的路网特性,合理安排发车、规划配送路径和顺序,从而降低配送成本,为物流企业运营车辆和优化配送提供参考。

扩展帝国竞争算法求解分布式不相关并行机车间调度问题

针对考虑加工约束的分布式不相关并行机车间调度问题,以总运输成本、工厂间并行机齐停评价函数和工件种类平均切换次数均衡评价函数为优化目标,提出一种扩展帝国竞争算法进行求解。该算法在原始帝国竞争算法的基础上,增加了适于工厂分配的初始化工厂-工件序列群;根据传统帝国竞争算法容易陷入局部最优的缺点,将较劣序列同化分为了外部同化机制和内部同化机制,采用局部和全局相结合的搜索方式实现扩展帝国竞争算法的智能搜索行为;采用部分匹配交叉和单点变异更新工厂-工件序列群,保证工厂-工件序列的多样性。最后设计3个不同规模12个算例,通过仿真实验验证所提算法的有效性,同时对比相关领域研究成果验证了该算法在求解分布式多目标不相关并行机调度问题方面的优越性。

新质生产力赋能产业链供应链韧性提升研究——来自上市公司的经验证据

新质生产力以提升全要素生产率为核心,以颠覆式创新为主导不断推动产业变革。在大国博弈的时代背景下,文章通过供需关系匹配、供需关系维持以及供应质量提升三个维度对产业链供应链韧性的内涵与机制进行理论分析。通过2009—2022年中国上市公司高度细化的“上游企业—下游企业—年份”数据集,实证检验了新质生产力对产业链供应链韧性的影响。研究发现,新质生产力显著促进供需关系匹配、供需关系维持以及供应质量提升,进而提升产业链供应链韧性,该结论在经过内生性问题处理以及一系列稳健性检验后依然成立。机制检验结果表明,新质生产力通过降低协调沟通成本与运输库存成本提升产业链供应链韧性。此外,新质生产力对产业链供应链韧性的提升效果存在明显差异,在大型供应商、国有供应商以及高市场化地区样本中,新质生产力的促进作用更明显。研究结论为新质生产力提升产业链供应链韧性提供了经验支持,为加快产业链供应链韧性与安全水平提供了政策启示。