scholarly journals Bi-Objective Modelling for Hazardous Materials Road–Rail Multimodal Routing Problem with Railway Schedule-Based Space–Time Constraints

Author(s):  
Yan Sun ◽  
Maoxiang Lang ◽  
Danzhu Wang
Urban Studies ◽  
2020 ◽  
pp. 004209802091641
Author(s):  
Zifeng Chen ◽  
Anthony Gar-On Yeh

The concept of conventional place-based accessibility, despite being well researched, tends to ignore people’s space–time constraints arising from mandatory activities (e.g. work and household duties), which confine people’s potential movement and delimit the accessible opportunities. As people with different socioeconomic statuses may have different space–time constraints even while living in similar locations, using the place-based measures could lead to an underestimation of accessibility inequality. This study applies a space–time measure to unravel the disparities in service accessibility in suburban China. Since the late 1970s, suburbanisation in Chinese cities has fostered income inequality and has elevated other dimensions (e.g. institutional status and gender) of disparity within each income class. Within this context, we conduct a case study of suburban neighbourhoods in Guangzhou, based on the activity diary data derived from a home-based questionnaire survey. Findings indicate that the use of a space–time measure effectively captures the disparities in service accessibility among residents in suburban Guangzhou. On the basis of structural equation modelling, we further identify that certain socioeconomic groups (e.g. high-income residents, public sector workers, local hukou holders, male household heads and welfare housing residents) tend to experience fewer space–time constraints from rigid activities, such as work, commuting and household duties, and are thus more advantaged in accessing service facilities. These findings imply that urban planning should address the space–time perspective to promote equal service access for the highly heterogeneous social groups in suburban China and to incorporate time-sensitive policies (e.g. flexitime policies).


1997 ◽  
Vol 1602 (1) ◽  
pp. 101-109 ◽  
Author(s):  
João Coutinho-Rodrigues ◽  
John Current ◽  
João Climaco ◽  
Samuel Ratick

Hazardous materials (hazmat) logistics management has received increased attention in the past two decades. Important decisions in such management include the selection of sites for hazmat processing and storage, the selection of transportation routes from sources to processing facilities, and the determination of quantities of hazmat shipped over these routes. These decisions are frequently based on multiple criteria (e.g., cost, risk, equity). A personal computer–based, interactive spatial decision-support system was designed to assist decision makers with such problems. Although presented within the framework of a hazmat problem, the system’s components can be modified to analyse any multiobjective location, routing, or location-routing problem.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Bochen Wang ◽  
Qiyuan Qian ◽  
Zheyi Tan ◽  
Peng Zhang ◽  
Aizhi Wu ◽  
...  

This study investigates a multidepot heterogeneous vehicle routing problem for a variety of hazardous materials with risk analysis, which is a practical problem in the actual industrial field. The objective of the problem is to design a series of routes that minimize the total cost composed of transportation cost, risk cost, and overtime work cost. Comprehensive consideration of factors such as transportation costs, multiple depots, heterogeneous vehicles, risks, and multiple accident scenarios is involved in our study. The problem is defined as a mixed integer programming model. A bidirectional tuning heuristic algorithm and particle swarm optimization algorithm are developed to solve the problem of different scales of instances. Computational results are competitive such that our algorithm can obtain effective results in small-scale instances and show great efficiency in large-scale instances with 70 customers, 30 vehicles, and 3 types of hazardous materials.


2019 ◽  
Vol 206 ◽  
pp. 976-986 ◽  
Author(s):  
Gustavo A. Bula ◽  
H. Murat Afsar ◽  
Fabio A. González ◽  
Caroline Prodhon ◽  
Nubia Velasco

Motor Control ◽  
2013 ◽  
Vol 17 (4) ◽  
pp. 323-339
Author(s):  
Yeou-Teh Liu ◽  
Tsung-Yu Hsieh ◽  
Karl M. Newell

Algorithms ◽  
2018 ◽  
Vol 11 (5) ◽  
pp. 69 ◽  
Author(s):  
Lucia Cassettari ◽  
Melissa Demartini ◽  
Roberto Mosca ◽  
Roberto Revetria ◽  
Flavio Tonelli

2017 ◽  
Vol 2017 ◽  
pp. 1-11
Author(s):  
Liangpeng Gao ◽  
Yanjie Ji ◽  
Yang Liu ◽  
Baohong He

Interactions among family members can yield valuable information for interpreting individual travel decisions. Typically, each family member plays a set role and travel decisions are made by considering the combined needs of household members. This study investigates both multiactivity and multiperson interactions in urban nuclear families and proposes the novel concepts of “activity-restriction degree” and “activity-constraint niche” to quantify the degree of space-time constraints within time geography. A structural equation model is employed to analyze intrahousehold interactions based on individual activity-travel patterns during the workday. The results indicate that the links between family members reflect behavioral responses (with constraints) between individuals and other family members. Household interaction constraints not only influence individual travel decisions but also affect the realization of the household activity for everyone. These interactions lead to reasonable adjustments and mutual support and to the identification of efficient activity patterns that meet the demands of the entire household.


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