Research Output
Articles
Publication Date: 2020
Transportation (00494488)47(1)pp. 417-443
Due to the interaction among different planning levels and various travel demands during a day, the transit network planning is of great importance. In this paper, a bi-objective multi-period planning model is proposed for the synchronization of timetabling and vehicle scheduling. The main aim of the problem is to minimize the weighted transfer waiting time in the interchange stations along with the operational costs of vehicles. In order to demonstrate the effectiveness of the proposed integrated model, a real case study of Tehran subway is considered. The proposed model is solved by the ε-constraint method and some outstanding results are achieved. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.
Publication Date: 2020
KSCE Journal of Civil Engineering (12267988)24(10)pp. 3050-3063
The disaster response routes play a crucial role in transporting injured people and goods during the 72 golden hours after disaster. These routes connect the major disaster relief centers. Prior identification of the disaster response routes for a city enables the response teams to reach the disaster locations quickly and conduct relief and rescue operations without being obstructed by the outbound flow of evacuees from the city. These routes should not generally be used by the public unlike the evacuation routes. In this paper, a multi-objective stochastic disaster response routes design problem is presented. In this study, with the goal of reducing vulnerability, the disaster response routes network can be protected against disaster scenarios to maintain its connectivity using more independent routes. An exact approach including a bounded objective function method for considering the multi-objective functions, including the network factors (OD connectivity, vulnerability, and management) and an exact method (branch-and-cut) for solving the proposed model are suggested. The results for Sioux-Falls and Tehran networks show the effectiveness of the model. © 2020, Korean Society of Civil Engineers.
Babaei, M.,
Shariat mohaymany, A.,
Nikoo, N.,
Ghaffari, A. Publication Date: 2019
Journal of Humanitarian Logistics and Supply Chain Management (20426747)9(2)pp. 250-269
Purpose: One of the problems in post-earthquake disaster management in developing countries, such as Iran, is the prediction of the residual network available for disaster relief operations. Therefore, it is important to use methods that are executable in such countries given the limited amount of accurate data. The purpose of this paper is to present a multi-objective model that seeks to determine the set of roads of a transportation network that should preserve its role in carrying out disaster relief operations (i.e. known as “emergency road network” (ERN)) in the aftermath of earthquakes. Design/methodology/approach: In this paper, the total travel time of emergency trips, the total length of network and the provision of coverage to the emergency demand/supply points have been incorporated as three important metrics of ERN into a multi-objective mixed integer linear programming model. The proposed model has been solved by adopting the e-constraint method. Findings: The results of applying the model to Tehran’s highway network indicated that the least possible length for the emergency transportation network is about half the total length of its major roads (freeways and major arterials). Practical implications: Gathering detailed data about origin-destination pair of emergency trips and network characteristics have a direct effect on designing a suitable emergency network in pre-disaster phase. Originality/value: To become solvable in a reasonable time, especially in large-scale cases, the problem has been modeled based on a decomposing technique. The model has been solved successfully for the emergency roads of Tehran within about 10 min of CPU time. © 2019, Emerald Publishing Limited.
