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Intermodal Freight Network Design for Transport of Perishable Products 被引量:4
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作者 Maxim A. Dulebenets Eren E. Ozguven +1 位作者 Ren Moses Mehmet B. Ulak 《Open Journal of Optimization》 2016年第4期120-139,共20页
The amount of perishable products transported via the existing intermodal freight networks has significantly increased over the last years. Perishable products tend to decay due to a wide range of external factors. Su... The amount of perishable products transported via the existing intermodal freight networks has significantly increased over the last years. Perishable products tend to decay due to a wide range of external factors. Supply chain operations mismanagement causes waste of substantial volumes of perishable products every year. The heretofore proposed mathematical models optimize certain supply chain processes and reduce decay of perishable products, but primarily deal with local production, inventory, distribution, and retailing of perishable products. However, significant quantities of perishable products are delivered from different continents, which shall increase the total transportation time and decay potential of perishable products as compared to local deliveries. This paper proposes a novel optimization model to design the intermodal freight network for both local and long-haul deliveries of perishable products. The objective of the model aims to minimize the total cost associated with transportation and decay of perishable products. A set of piecewise approximations are applied to linearize the non-linear decay function for each perishable product type. CPLEX is used to solve the problem. Comprehensive numerical experiments are conducted using the intermodal freight network for import of the seafood perishable products to the United States to draw important managerial insights. Results demonstrate that increasing product decay cost may significantly change the design of intermodal freight network for transport of perishable products, cause modal shifts and affect the total transportation time and associated costs. 展开更多
关键词 freight transportation Network Design Perishable Products Shelf Life OPTIMIZATION
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Calibration and Validation of Strategic Freight Transportation Planning Models with Limited Information 被引量:1
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作者 Bart Jourquin 《Journal of Transportation Technologies》 2016年第5期239-256,共18页
Strategic transportation network models are often used as support tools in the framework of decisions to be taken at the policy level, such as the Trans-European Network projects. These models are mostly setup using a... Strategic transportation network models are often used as support tools in the framework of decisions to be taken at the policy level, such as the Trans-European Network projects. These models are mostly setup using aggregated or limited data. If their calibration is regularly mentioned in the literature, their validation is barely discussed. In this paper, several modal choice model specifications that make only use of explanatory variables available at the network level are described and applied to a large scale case. A validation exercise is performed at three levels of aggregation. The paper is designed from a strategic transport planning perspective, and does not present new modal choice formulations or assignment procedures. Its main added value is the focus on calibration and validation considerations. Despite the limited explanatory information used, the global performance of the best models can be considered as satisfactory. However, the quality of the models varies from mode to mode, the use of railway transport being the most difficult to predict without more specific input. 展开更多
关键词 CALIBRATION VALIDATION NETWORK freight transport Modal Choice ASSIGNMENT
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Estimating Elasticities for Freight Transport Using a Network Model: An Applied Methodological Framework
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作者 Bart Jourquin 《Journal of Transportation Technologies》 2019年第1期1-13,共13页
This paper presents a general framework that can be used to estimate direct and cross elasticities for freight transport using a network model. This methodology combines operational research (network assignments in a ... This paper presents a general framework that can be used to estimate direct and cross elasticities for freight transport using a network model. This methodology combines operational research (network assignments in a geographical information system) with more classical econometrics (multinomial logit choice models). The application of the method to a real-world case is illustrated by a simple model that relies on the generalized cost of transport as the only explanatory variable in the utility function. The methodological framework allows, however, for the implementation of more complex functions. Beside the generalized cost functions for road, rail and inland waterways transport, the network model needs origin-destination matrixes and digitized networks. They are imported from ETIS Plus, a European transport policy information system. A set of direct and cross elasticities is presented. The estimated values are obtained using two methods: the first computes standard elasticities, while the second estimates arc elasticities. Figures are presented for Europe and for a large region around the Benelux countries, where more competition exists between the three modes of interest. 展开更多
关键词 ELASTICITY Estimations freight transport Network MODEL CONDITIONAL LOGIT MODEL Validation
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Model of Freight Transportation between the Czech Republic and the US
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作者 Helena Binova Petr Toman 《Journal of Civil Engineering and Architecture》 2015年第4期475-484,共10页
Maritime transportation is one of the most important and extensive transportation modes in the world. Maritime transportation is the backbone of contemporary world trade and therefore special attention should be paid ... Maritime transportation is one of the most important and extensive transportation modes in the world. Maritime transportation is the backbone of contemporary world trade and therefore special attention should be paid to all subjects concerning this mode of transportation. It is also necessary to complement maritime transportation by other modes, such as rail and/or truck (road). This article deals with the problems of maritime transportation and provides the summary of recent developments, trends and statistics mainly on transatlantic maritime routes (Europe to US). Besides maritime transportation, this thesis also reviews the trends and statistics of rail and truck (road) transportation in US and Europe. The authors considers four Czech biggest cities (points of origin), five European ports, eight US ports and 10 biggest cities in US (points of destination). The adapted TCMMSP (transnational collaborative multi-mode shipping problem) is applied to this case study and it seeks to solve the transportation of a set of five shipments with unique O-D (origin-destination) pairs and volume. The end of the thesis summarizes the results and analyses the average costs, optimal set volume, optimal shipment routing and port analysis. 展开更多
关键词 Maritime transport freight trade Czech Republic US.
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Accessibility Measures in Modal Choice Models: A Proof of Concept Applied to Freight Transport
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作者 Bart Jourquin 《Journal of Transportation Technologies》 2023年第1期38-60,共23页
Modal choice models applied to interregional or international freight transportation network models are often based on rather coarse origin-destination matrices, containing annual transported tonnages between (sub)reg... Modal choice models applied to interregional or international freight transportation network models are often based on rather coarse origin-destination matrices, containing annual transported tonnages between (sub)regions, for instance. Generally, only basic (sometimes constructed) independent variables (transportation costs or transit times) are used because other variables such as shipment sizes, service frequencies, etc. are not available. Using origin-destination matrices and an assignment model, it is also possible to compute spatial accessibility measures that can further be used as additional explanatory variables. Indeed, several published studies have identified network accessibility as an important element in the mode-choice decision. This paper also shows that the inclusion of an accessibility measure in the utility functions of a logit model substantially improves the performance of a transportation network model, both in the modal choice and the assignment levels of the classical four-step model. Consequently, the assignment of the estimated modal demands results in more accurate estimated traffic on the networks. The model presented in this paper is to be considered as a proof of concept because its workflow should further be streamlined to make it easily useable by modelers. 展开更多
关键词 freight transport Model Modal Choice ACCESSIBILITY ASSIGNMENT
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Empirical Analysis of Multiple-Criteria Decision-Making (Mcdm) Process for Freight Transportation Mode Selection
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作者 Emmanuel Anu Thompson Ruhaimatu Abudu Shiyuan Zheng 《Journal of Transportation Technologies》 2022年第1期28-41,共14页
I<span style="font-family:Verdana;">n Ghana, freight transport is growing continuously every year due to its location and business processes. However, road transport carries 86% of frei</span><... I<span style="font-family:Verdana;">n Ghana, freight transport is growing continuously every year due to its location and business processes. However, road transport carries 86% of frei</span><span style="font-family:Verdana;">ght despite its numerous negative impacts. Hence, the government has invested in rail transport, with 70% of its capacity is for freight transport in her busy freight transport corridor (eastern transport regions of Ghana). Thus, awareness of criteria considered when deciding on freight transport becomes vital. Hence, this study aims to improve the understanding of the fa</span><span style="font-family:Verdana;">ctors of freight transport mode selection in Ghana from the decision-</span><span style="font-family:Verdana;">making process by identifying criteria that affect their decisions on mode transportation. The combination of Fuzzy AHP and Topsis is used to find the weights and suggest suitable alternatives for the decision-makers in the Eastern transport regions of Ghana. The result of this study shows that the criteria to consider when selecting freight transport mode in the regions are prioritized in other of Transport cost (0.6544), transport Time factors (0.2562), reliability, and flexibility (0.0605), and security, Risk of damage and lose factors (0.0287). Additionally, the suitable mode(s) of transportation in the stated corridor is owned truck carrier transport compared to the railroad, road-barge, and Contracted Carrier, thus, in descending order. The results provide organizations to prioritize these factors when deciding to select freight transport mode. At the same time, the government must remove some inputs that result in high transport cost</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;">, enforce</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">policies, and invest in the appropriate mode.</span> 展开更多
关键词 freight transport Mode MCDM Fuzzy AHP TOPSIS and Ghana
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The Comparison of Basic Transportation Infrastructure and Freight Villages' Locations between Germany and Turkey
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作者 Cenk Hamamcloglu Senay Oguztimur 《Journal of Traffic and Transportation Engineering》 2017年第2期77-92,共16页
Transportation infrastructure and logistics facilities are partly different in both Turkey and Germany in terms of geographical location, industrial history and economy. The world witnesses the highest logistics perfo... Transportation infrastructure and logistics facilities are partly different in both Turkey and Germany in terms of geographical location, industrial history and economy. The world witnesses the highest logistics performance index score in Germany. Meanwhile, Turkey experiences a promptly development. As Europe's largest economy and second most populous nation, Germany leads in developing logistics strategies and services as a key member of the EU's economic and political structure. On the other hand, Turkey possesses a strategic location between the continents but conventionally problems in transportation mode sprit and interconnectivity of systems that interfere with "hub" role for its region and achieve economic benefit. This paper aims to focus on transportation mode sprit and location decision of freight villages in Germany to understand the mind behind success. With this purpose, first section is substantially based on secondary data gathered from Turkish/German Statistical Institutes, Ministries of Transportation and NGO's of the sector and academic studies. Finally, the lessons to be taken for Turkey's future policies are presented. Results indicate that, the finest detail is hidden behind the railway investments and their connections with other modes for Turkey. Germany's logistics workforce and infrastructure is geographically spread all over the country, but in Turkey, unbalanced regional development force country to polarised developed regions in the western part. 展开更多
关键词 transportation freight village GERMANY Turkey.
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Development of Freight Transport in Indonesia: Towards Sustainability Transport
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作者 Elly Sinaga 《Journal of Traffic and Transportation Engineering》 2021年第1期19-25,共7页
Indonesia as the largest archipelagic country has potential market for freight transport.Unfortunately according to Logistics Performance Index(LPI)by the World Bank in 2012,Indonesia National Logistics System perform... Indonesia as the largest archipelagic country has potential market for freight transport.Unfortunately according to Logistics Performance Index(LPI)by the World Bank in 2012,Indonesia National Logistics System performance still have not optimal.Congestion become one of problem issue which caused the cost of logistics in Indonesia is more expensive for the similar routes in other Asia country.Besides,the use of road transport for freight is still dominating in Indonesia.In order to accelerate the Indonesia economy development and solve out the transport modal split issue,the government has declared the Master Plan for the Acceleration and Expansion of Indonesian Economic Development(MP3EI).In which through this policy the government is trying to improve and develop all the infrastructure of the transport sector including multimodal transport and greenhouse gas emissions(GHG)reduction.This paper tries to give explanation toward logistics transport and its problem,current condition on freight transport and the government policies in Indonesia.The method is usingdescriptive analyse with qualitative data and interview method to gain the detail information from the stakeholder. 展开更多
关键词 freight transport LOGISTICS Indonesia mp3ei MULTIMODAL GREENHOUSE
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Choosing Multimodal Freight Mix: An Integrated Multi-Objective Multicriteria Approach
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作者 Mohammad Anwar Rahman 《Journal of Transportation Technologies》 2024年第3期402-422,共21页
Multimodal freight transportation emerges as the go-to strategy for cost-effectively and sustainably moving goods over long distances. In a multimodal freight system, where a single contract includes various transport... Multimodal freight transportation emerges as the go-to strategy for cost-effectively and sustainably moving goods over long distances. In a multimodal freight system, where a single contract includes various transportation methods, businesses aiming for economic success must make well-informed decisions about which modes of transport to use. These decisions prioritize secure deliveries, competitive cost advantages, and the minimization of environmental footprints associated with transportation-related pollution. Within the dynamic landscape of logistics innovation, various multicriteria decision-making (MCDM) approaches empower businesses to evaluate freight transport options thoroughly. In this study, we utilize a case study to demonstrate the application of the Technique for Order Preference by Similarity to the Ideal Solution (TOPSIS) algorithm for MCDM decision-making in freight mode selection. We further enhance the TOPSIS framework by integrating the entropy weight coefficient method. This enhancement aids in assigning precise weights to each criterion involved in mode selection, leading to a more reliable decision-making process. The proposed model provides cost-effective and timely deliveries, minimizing environmental footprint and meeting consumers’ needs. Our findings reveal that freight carbon footprint is the primary concern, followed by freight cost, time sensitivity, and service reliability. The study identifies the combination of Rail/Truck as the ideal mode of transport and containers in flat cars (COFC) as the next best option for the selected case. The proposed algorithm, incorporating the enhanced TOPSIS framework, benefits companies navigating the complexities of multimodal transport. It empowers making more strategic and informed transportation decisions. This demonstration will be increasingly valuable as companies navigate the ever-growing trade within the global supply chains. 展开更多
关键词 Multimodal freight transport MCDM TOPSIS Entropy Technique COFC
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Urban Freight Consolidation Model for Post-Hauler Planning
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作者 Mohammad Anwar Rahman 《Journal of Transportation Technologies》 2024年第2期255-272,共18页
Freight transportation in urban areas has increased significantly in a shorter period due to the widespread use of e-commerce, fast delivery, and population growth. Recently, a noticeable government initiative aimed a... Freight transportation in urban areas has increased significantly in a shorter period due to the widespread use of e-commerce, fast delivery, and population growth. Recently, a noticeable government initiative aimed at creating an effective, acceptable, and sustainable city logistics policy. This paper examines freight consolidation as a transportation strategy for optimizing last-mile delivery costs. Freight consolidation involves combining smaller shipments from various origins into a single, larger shipment for more efficient transportation to a common destination. This approach is particularly beneficial for last-mile delivery, where frequent deliveries of smaller quantities are frequently visible. Finally, we provide an illustrative example targeting urban freight stakeholders for practicing possible consolidation methodology. The result in the illustrative example shows that freight with 3-day consolidation, despite the delay penalty, is cheaper than daily shipping, and both are cheaper than 2-day consolidated shipping. The study will benefit urban businesses and freight services. 展开更多
关键词 freight Consolidation Urban transport Intermodal Last-Mile Delivery
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Spatial Accessibility to Shopping Malls in Nanjing,China:Comparative Analysis with Multiple Transportation Modes 被引量:1
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作者 LI Ang CHEN Jie +2 位作者 QIAN Tianlu ZHANG Wenhan WANG Jiechen 《Chinese Geographical Science》 SCIE CSCD 2020年第4期710-724,共15页
This study attempts to evaluate the rationality of the spatial layout of shopping malls and identify the urban area with poor shopping mall accessibility,as well as to provide a reference and assist decision-making fo... This study attempts to evaluate the rationality of the spatial layout of shopping malls and identify the urban area with poor shopping mall accessibility,as well as to provide a reference and assist decision-making for planning.Using the case of Nanjing,China,this study developed a method to evaluate the accessibility of shopping malls by three transport modes(car traffic,public transit,and bicycle).Specially,we divide the urban space into a regular hexagonal grid and harvest the total travel time from each of 7204 hexagon centroids to each of 129 shopping malls using the Baidu Internet map.The door-to-door travel time approach is used to evaluate all travel stages(walking,waiting,transfer,and transportation)based on travel time calculations.We further divide the shopping malls into two levels(super-regional and regional)based on the Dianping App’s information and develop the indicator of accessibility to shopping malls:the number of shopping malls within tolerance time thresholds and apply the closest facility and cumulative opportunities methods to measure accessibility scores.The results show that the accessibility estimations vary greatly with transport modes.The accessibility of shopping malls presents a concentric ring trend centered on the city center under the car traffic and bicycle modes.And public transit accessibility tends to axially extend due to the topology of bus routes and metro lines.In particular,we observe that the accessibility of shopping malls in Nanjing has an uneven spatial distribution pattern,with high accessibility values in the central urban areas and lots of underserved areas in urban fringe regions.Based on the accessibility measurements,we finally map the poor accessibility area and propose corresponding implications for urban planning. 展开更多
关键词 spatial accessibility shopping mall access transport mode door-to-door travel time internet maps
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Discussion on the Logistics Construction of Railway Container Freight Stations
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作者 Chi Yonglin(迟永林) +1 位作者 Zhang Jin(张锦) 《Journal of Southwest Jiaotong University(English Edition)》 2002年第2期122-129,共8页
From the perspective of logistics, the article discusses some essential functions and service functions of railway container freight stations. Then it plans the construction of the logistics operation system of contai... From the perspective of logistics, the article discusses some essential functions and service functions of railway container freight stations. Then it plans the construction of the logistics operation system of container freight stations, and designs five main operating yards such as deconsolidation and groupage .yard, storage and distribution yard, container receiving-departure yard, container stack yard, and special cargo yard. The management pattern is discussed under the direction of modern business management theory. The ideas presented in this article is significant to the construction of railway container freight stations. 展开更多
关键词 cargo movement freight stations railway terminals container transport railway container freight station logistics construction
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Optimization Model of Regional Comprehensive Freight Hub Location
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作者 陈大伟 徐中 李旭宏 《Journal of Southwest Jiaotong University(English Edition)》 2009年第3期240-247,共8页
An optimization model for the regional comprehensive freight hub location problem was built up from the viewpoint of the minimum cost of freight system. The construction method for regional comprehensive intermodal fr... An optimization model for the regional comprehensive freight hub location problem was built up from the viewpoint of the minimum cost of freight system. The construction method for regional comprehensive intermodal freight network was put forward, and three constraints of the reasonable and feasible path of the intermodal transport, i. e. , reasonable sequence, reasonable freight distance, and reasonable conversion times, were proposed according to the general concepts of the intermodal freight. Then the method for solving the model was given based on the super network and genetic algorithm. Finally, the model and the solution were verified by case study. 展开更多
关键词 Comprehensive transportation freight hubs Hub location
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多情景模拟下的跨境铁路运输时效研究——以中老铁路为例 被引量:3
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作者 黄洁 熊美成 +2 位作者 王姣娥 高阳 李永玲 《地理科学》 CSSCI CSCD 北大核心 2024年第1期91-98,共8页
跨境铁路运输是中国与周边国家陆路联通的重要环节。跨境铁路运输时效既受线路畅通情况、基础设施技术等级等“硬联通”因素的制约,也受到海关条例、口岸畅通水平等“软联通”因素的影响。因此,跨境铁路运输时效研究应充分考虑不同情景... 跨境铁路运输是中国与周边国家陆路联通的重要环节。跨境铁路运输时效既受线路畅通情况、基础设施技术等级等“硬联通”因素的制约,也受到海关条例、口岸畅通水平等“软联通”因素的影响。因此,跨境铁路运输时效研究应充分考虑不同情景,以期更科学地模拟运输时长的变化机理。本文以中老铁路(中国昆明−老挝万象,简称中老铁路)为例,在梳理中老铁路沿线地区社会经济概况及基础设施发展水平的基础上,考虑不同运营速度、通关时间、铁轨换装、多式联运等因素,构建了长途跨境运输时间的计算模型,采用多情景模拟方法,解析了中老铁路运的优势距离及客货运时效变化。研究表明:①中老铁路有助于沿线跨境运输时间显著减少。相比公路运输,客货运时间优势均超过20%;②通关时间是影响跨境铁路运输的关键要素之一,占运输总时长的20%~60%;③铁海联运是中老铁路运输进一步提升运输效率的途径,能有效缩短老挝至日本的总运输时间。 展开更多
关键词 跨境运输 客货运组织 中老铁路 情景模拟 运输时效
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ComplexTrans-Global Rail-Road Transportation System Economical and Clustered Individual and Individualised Public Transport also Prevents the Spread of Covid 19
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作者 Jiri Hofman Roman Cermak 《Journal of Civil Engineering and Architecture》 2021年第5期255-276,共22页
Land transport can no longer meet the requirements.European transport can be described by these words−crowded motorways and cities,dangerous emissions,ubiquitous traffic accidents,delays,expensive railways.Solutions a... Land transport can no longer meet the requirements.European transport can be described by these words−crowded motorways and cities,dangerous emissions,ubiquitous traffic accidents,delays,expensive railways.Solutions are being sought to transfer a large part of passengers and especially freight transport to(high-speed)rail,and efforts are moving towards electromobility,car-sharing,5G-connectivity,autonomous driving,MaaS(Mobility as a Service)-coordinated transport or hyperloop-type solutions.However,all these solutions have additional challenges and limitations.Solutions are not being searched where they really exist-in the mutual adaptation of road and rail vehicles and their deep cooperation.The ComplexTrans project shows that simply adapting the dimensions and functions of road and rail vehicles can eliminate(or at least significantly reduce)all the problems of existing land transport.The main features of the ComplexTrans system are sufficient parking spaces,reduction of urban and non-urban congestion,electric vehicles with unlimited range and cheaper than standard cars,cheaper and more accessible battery charging,“autonomous ride”,solving the overlap between passenger and freight rail transport and making it self-financing,transferring intercity freight transport to rail,replacing part of continental air transport and many others.The cost-effective and clustered individual transport and individualised public transport of the ComplexTrans system also bring very significant reductions in the risk of transmission of covid-19 and other contagious diseases during transport. 展开更多
关键词 land transport intermodal transport mixed transport road and rail transport passenger and freight transport city transport intercity transport private transport public transport MAAS covid prevention in public transport e-mobility autonomous ride car parking traffic density reduction platooning range extender battery exchange energy need reduction CO2 emissions reduction V2G transport and energy sector cooperation energy safety
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Evaluation and Effectiveness of Reallocating Traffic Signal Timing at Corridors with High Freight Volume
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作者 Ijeoma Ihuoma-Walter Celeste Chavis Adewole Oladele 《Journal of Architectural Environment & Structural Engineering Research》 2022年第2期25-33,共9页
The COVID-19 pandemic drastically altered traffic patterns across the globe.With more people staying at home and relying on delivery services,there was a reduction in passenger car traffic but an increase in freight t... The COVID-19 pandemic drastically altered traffic patterns across the globe.With more people staying at home and relying on delivery services,there was a reduction in passenger car traffic but an increase in freight traffic.This study investigates the changes in traffic volume and mode splits during the COVID-19 pandemic at the intersection of Broening Highway and Holabird Avenues and investigates traffic signal reallocation strategies that account for the changes in traffic.This study considers morning peak traffic volumes before and during COVID.A methodology was developed to evaluate and measure freight volumes and emissions.From the literature,the cost per kilogram of CO,VOC,and NOx was$5.85,$3,37,and$12.53,respectively.The intersection operated at a level of service(LOS)of C both pre-COVID and during COVID.Traffic volume decreased by 24.3%during COVID at the study location;car volumes declined by 50%,and truck volumes increased by 130%.The total rate of emissions decreased by 22.6%. 展开更多
关键词 Multi-modal transportation Signalized intersection freight Vehicle and persons delay COVID Value of time
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Development of a Freight Demand Model with an Application to California
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作者 Robert Lim Zhen(Sean)Qian H.M.Zhang 《International Journal of Transportation Science and Technology》 2014年第1期19-38,共20页
This paper discusses the disaggregation of the Federal Highway Administration’s Freight Analysis Framework(FAF)database(version 3.0)on freight origin-destination data and the development of linear regression equation... This paper discusses the disaggregation of the Federal Highway Administration’s Freight Analysis Framework(FAF)database(version 3.0)on freight origin-destination data and the development of linear regression equations to describe the relationships between commodity-based freight trip productions/attractions to specific economic variables.Instead of generating a production/attraction equation for each commodity,commodities are grouped in certain ways to simplify model development and application.We consider three grouping methods and two model selection criteria(with and without intercepts),which are compared in terms of goodness of fit with two data sets(FAF versions 2.0 and 3.0).Furthermore,the freight generation models are validated using county-level economic data in California and applied to predict year 2015 commodity outputs.The results of this study can help city,county,metropolitan and state level planning agencies develop their own customized freight demand generation models without performing costly large-scale surveys. 展开更多
关键词 freight transportation Trip generation model FAF3 Commodity flow
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基于嵌入式技术的无人驾驶货运系统设计 被引量:1
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作者 梁瑞 《微型电脑应用》 2024年第2期74-76,共3页
针对目前货运行业人力成本高且效率低的问题,设计一种基于嵌入式技术的无人驾驶货运系统。该系统通过摄像头扫描目标地址即可携带货物自动到达并返回,同时对于复杂货运场合可实现多系统独立工作。设计采用嵌入式芯片STM32F4和串级PID算... 针对目前货运行业人力成本高且效率低的问题,设计一种基于嵌入式技术的无人驾驶货运系统。该系统通过摄像头扫描目标地址即可携带货物自动到达并返回,同时对于复杂货运场合可实现多系统独立工作。设计采用嵌入式芯片STM32F4和串级PID算法,通过K210和OpenMV摄像头模块采集地址和轨迹信息,实现货运系统的自动运送过程。经测试,该系统能准确完成货运任务,反应灵敏,性价比高,可广泛应用于货运场合。 展开更多
关键词 嵌入式技术 无人驾驶 货运 PID控制
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基于多目标进化的超限超重货物运输专列路径优化方法
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作者 张英贵 刘家忱 雷定猷 《中国铁道科学》 EI CAS CSCD 北大核心 2024年第3期138-148,共11页
针对超限超重货物运输专列路径优化问题,引入限界改造和桥梁加固要素,以铁路运能损失、运输时间和运输费用的最小化为优化目标,构建铁路超限超重货物运输专列路径优化模型;考虑专列同时运送多件超限超重货物的特点,设计货物综合投影算法... 针对超限超重货物运输专列路径优化问题,引入限界改造和桥梁加固要素,以铁路运能损失、运输时间和运输费用的最小化为优化目标,构建铁路超限超重货物运输专列路径优化模型;考虑专列同时运送多件超限超重货物的特点,设计货物综合投影算法,并以Pareto支配关系框架下的NSGA-Ⅱ多目标进化算法为基础,结合基于移动不可行解的自适应惩罚函数的约束处理技术及超限超重货物运输专列开行特征,提出一种基于多目标进化的铁路超限超重货物运输专列路径优化算法。实例分析结果表明:该方法能高效合理地处理路径优化任务中的多个目标;与常用的3种约束多目标算法相比,设计的优化算法能使计算耗时降低0.24%~29.94%、超体积指标值提高4.25%~13.11%,并得到一组收敛性和多样性更好的相对最优方案。该方法克服了传统专列路径优化中单纯依靠经验或从备选方案中择优的弊端,可为铁路超限超重货物运输专列路径决策提供技术支持。 展开更多
关键词 铁路货物运输 超限超重货物运输专列 路径优化 多目标进化 约束处理技术 自适应惩罚函数
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考虑实质性降本的物流成本评价指标及相关对策建议
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作者 安然 孙东泉 冯淑贞 《交通运输研究》 2024年第4期103-114,136,共13页
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... 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。 展开更多
关键词 宏观物流成本 单位货物运输周转量物流成本 运输费用 保管费用 管理费用
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