Hub location-routing network design under incomplete hub links and direct shipment
حسین
کریمی
خواجه نصیر الدین طوسی، مهندسی صنایع
author
text
article
2014
per
In a hub location problem network, the flow originated from an origin and shipped to a destination via some selected intermediate nodes called hub nodes since using discount factor of hubs. The hub nodes are fully interconnected in traditional hub location problem. In any origin-destination path there exists at least one hub element. Rather than directly connecting any pair of locations, all the paths are handled by the hub node. In this paper, a general configuration of hub location problems is considered. The model is presented for hub location-routing problem which any network topology can be structured. This model application is in the public transportation, telecommunication systems and financial networks. Incomplete hub network is deigned in the model. Furthermore, location and routing decisions are considered simultaneously in the model besides multiple allocation strategy. Moreover, non-hub nodes can be connected directly. Objective function of this model is minimized transshipment cost of flows and cost of constructing the network. Family of valid inequalities and some preprocessing are proposed to strengthening the model linear relaxation lower bound and improving solution time. Computational results over test problems driven from the literature show that using all valid inequalities and preprocessing perform better than using each of them separately and solve the model in a reasonable solution time.
Journal of Transportation Research
مرکز تحقیقات راه ، مسکن و شهرسازی
1735-3459
11
v.
2
no.
2014
https://www.trijournal.ir/article_11512_d41d8cd98f00b204e9800998ecf8427e.pdf
Estimation of shadow prices for environmental pollutions CO2، NOx & SO2 in transportation sector
میرحسین
موسوی
دانشگاه الزهرا، علوم اجتماعی
author
عباس
شاکری
علامه طباطبایی، اقتصاد
author
text
article
2014
per
Regarding necessity the scientific and clear criteria utilization for evaluating environmental costs, this research estimated a stochastic output distance function by measuring the environmental pollution parameters via analyzing in the transportation sector, as well as collecting the survey inputs and outputs production data. According to the Pigou’s theory which says each polluter should pay the costs of its pollution, given the lack of appropriate analytical methods for environmental policymaking, in this paper we made an estimate of shadow prices for environmental pollutions resulting from fossil fuel consumption in transportation sector. Accordingly, the average shadow prices in the transportation sector during the period of time from 1357 to 1389 for pollutants including nitrogen oxides (NOx) is equal to -121469.7 rials per ton-kilometer, sulfur dioxide (SO2) is equal to -131936.9 rials per ton-kilometer and for carbon dioxide (CO2) is equal to -488.4381 rials per ton-kilometer. These results suggested as a basic measure for planning to environmental policymakers to have a better knowledge of related economical-environmental effects of transportation sector and environmental costs.
Journal of Transportation Research
مرکز تحقیقات راه ، مسکن و شهرسازی
1735-3459
11
v.
2
no.
2014
https://www.trijournal.ir/article_11513_d41d8cd98f00b204e9800998ecf8427e.pdf