scholarly journals Earliest Arrival Evacuation Planning: Two-Terminal Case

Author(s):  
Ram Uday Sah ◽  
Shree Ram Khadka

<p>Evacuation planning problem can be considered as a dynamic flow problem on the dynamic network. In a dangerous situation, as many individuals as possible should be rescued from a dangerous zone to a safety zone as quickly and efficiently as possible. The earliest arrival flow problem is to send a maximal amount of dynamic flow reaching the safety zone sink not only for the given time horizon, but also for any earlier moment of the time horizon. In this paper we discuss the optimization formulation of the earliest arrival evacuation planning problem with efficient solution procedure.</p><p><strong>Journal of Advanced College of Engineering and Management,</strong> Vol. 2, 2016, page: 57-62</p>

2018 ◽  
Vol 14 (1) ◽  
pp. 107-114
Author(s):  
Phanindra Prasad Bhandari ◽  
Shree Ram Khadka

Shifting as many people as possible from disastrous area to safer area in a minimum time period in an efficient way is an evacuation planning problem (EPP). Modeling the evacuation scenarios reflecting the real world characteristics and investigation of an efficient solution to them have become a crucial due to rapidly increasing number of natural as well as human created disasters. EPPs modeled on network have been extensively studied and the various efficient solution procedures have been established where the flow function satisfies the flow conservation at each intermediate node. Besides this, the network flow problem in which flow may not be conserved at nodes necessarily could also be useful to model the evacuation planning problem. This paper proposes an efficient solution procedure for maximum flow evacuation planning problem of later kind on a single-source-single-sink dynamic network with integral arc capacities with holding capability of flow (evacuees) in the temporary shelter at intermediate nodes. Journal of the Institute of Engineering, 2018, 14(1): 107-114


2019 ◽  
Vol 36 (1-2) ◽  
pp. 11-16
Author(s):  
Shree Ram Khadka ◽  
Phanindra Prasad Bhandari

Efficient evacuation plan with which a maximum evacuees can be sent as soon as possible from the disastrous place to the safe place is an important notion during the response phase of the disaster management. Such a plan in terms of optimization models has been extensively studied in a various scenarios, see [3]. The optimization models have been based on the flow conservation constraint which permits an evacuee to be taken out of the disastrous place only if it can be sent into the safe place. However, the evacuation plan model with no flow conservation can keep several evacuees in the relatively safe places besides the evacuees which could be sent into the safe place. In this paper, we describe an optimization model for the evacuation plan based on the non-conservation flow constraint with an efficient solution procedure which keeps a maximum evacuees on the prioritized intermediate places besides a maximum evacuees into the specified safe place.


2020 ◽  
Vol 37 (1-2) ◽  
pp. 1-13
Author(s):  
Iswar Mani Adhikari ◽  
Tanka Nath Dhamala

Evacuation planning problem deals with sending the maximum number of evacuees from the danger zone to the safe zone in minimum time as eciently as possible. The dynamic network flow models for various evacuation network topology have been found suitable for the solution of such a problem. Bus based evacuation planning problem (BEPP), as an important variant of the vehicle routing problem (VRP), is one of the emerging evacuation planning problems. In this work, an organized overview of this problem with a focus on their solution status is compactly presented. Arrival patterns of the evacuees including their transshipments at different pickup locations and their assignments are presented. Finally, a BEPP model and a solution for a special network are also proposed.


2020 ◽  
Vol 10 (1) ◽  
pp. 25-32
Author(s):  
Phanindra Prasad Bhandari ◽  
Shree Ram Khadka

The optimization model of the maximum flow evacuation planning problem efficiently sends a maximum number of evacuees along with the routes of their transshipment from the disastrous zone, the source, to the safe zone, the sink, over a given time horizon. The limitation of the problem with the flow conservation constraint at the intermediate nodes is that even one more evacuee cannot be sent out from the source, if the evacuee cannot reach the sink. However, evacuators must attempt to send out as many evacuees as possible to safer places despite the sink. There may be relatively safe places in between the source and the sink. The limitation is due to the flow conservation constraint. In this paper, we remodel the problem with non-conservation flow constraint and propose an efficient algorithm. With this approach one can send as many evacuees as in the flow conservation case from the source to the sink. Moreover, a maximum number of evacuees can also be sent to the relatively safe places in between the source and the sink. The routes of their transshipment can also be identified.


2015 ◽  
Vol 3 ◽  
pp. 44-53
Author(s):  
Phanindra Prasad Bhandari ◽  
Shree Ram Khadka

Evacuation planning is becoming crucial due to an increasing number of natural and human-created disasters over last few decades. One of the efficient ways to model the evacuation situation is a network flow optimization model. This model captures most of the necessities of the evacuation planning. Moreover, dynamic network contraflow modeling is considered a potential remedy to decrease the congestion due to its direction reversal property and it addresses the challenges of evacuation route planning. However, there do not exist satisfactory analytical results to this model for general network. In this paper, it is tried to provide an annotated overview on dynamic network contraflow problems related to evacuation planning and to incorporate models and solution strategies to them developed in this field to date.


2018 ◽  
Vol 13 (1) ◽  
pp. 108-116
Author(s):  
Phanindra Prasad Bhandari ◽  
Shree Ram Khadka

 An attempt of shifting as more people as possible and/or their logistics from a dangerous place to a safer place is an evacuation planning problem. Such problems modeled on network have been extensively studied and the various efficient solution procedures have been established. The solution strategies for these problems are based on source-sink path augmentation and the flow function satisfies the flow conservation at each intermediate node. Besides this, the network flow problem in which flow may not be conserved at node necessarily could also be used to model the evacuation planning problem. This paper proposes a model for maximum flow evacuation planning problem on a single-source-single-sink static network with integral arc capacities with holding capability of evacuees in the temporary shelter at intermediate nodes and extends the model into the dynamic case. Journal of the Institute of Engineering, 2017, 13(1): 108-116


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
YiHua Zhong ◽  
ShiMing Luo ◽  
Min Bao ◽  
XiaoDie Lv

When designing the underground logistics system, it is necessary to consider the uncertainty of logistics nodes, high cost, and high risk. This paper employed the theories of uncertain graph and dynamic programming to solve the network planning problem of underground logistics system. Firstly, we proposed the concepts of uncertainty measure matrix and vertices structure uncertainty graph by using uncertainty measure and uncertainty graph. Secondly, vertices structure uncertainty graph of the underground logistics system was constructed based on our proposed vertices structure uncertainty graph and the uncertainty of logistics nodes. Thirdly, the dynamic programming model of the underground logistics system was established, and its solution algorithm was also designed by improving simulated annealing. Finally, the correctness and feasibility of the method was validated by using a numerical example of the underground logistics system in Xianlin district, Nanjing City in China.


Author(s):  
Ram Chandra Dhungana ◽  
Tanka Nath Dhamala

Many large-scale natural and human-created disasters have drawn the attention of researchers towards the solutions of evacuation planning problems and their applications. The main focus of these solution strategies is to protect the life, property, and their surroundings during the disasters. With limited resources, it is not an easy task to develop a universally accepted model to handle such issues. Among them, the budget-constrained network flow improvement approach plays significant role to evacuate the maximum number of people within the given time horizon. In this paper, we consider an evacuation planning problem that aims to shift a maximum number of evacuees from a danger area to a safe zone in limited time under the budget constraints for network modification. Different flow improvement strategies with respect to fixed switching cost will be investigated, namely, integral, rational, and either to increase the full capacity of an arc or not at all. A solution technique on static network is extended to the dynamic one. Moreover, we introduce the static and dynamic maximum flow problems with lane reversal strategy and also propose efficient algorithms for their solutions. Here, the contraflow approach reverses the direction of arcs with respect to the lane reversal costs to increase the flow value. As an implementation of an evacuation plan may demand a large cost, the solutions proposed here with budget constrained problems play important role in practice.


Author(s):  
Wojciech Szynkiewicz ◽  
Jacek Błaszczyk

Optimization-based approach to path planning for closed chain robot systems An application of advanced optimization techniques to solve the path planning problem for closed chain robot systems is proposed. The approach to path planning is formulated as a "quasi-dynamic" NonLinear Programming (NLP) problem with equality and inequality constraints in terms of the joint variables. The essence of the method is to find joint paths which satisfy the given constraints and minimize the proposed performance index. For numerical solution of the NLP problem, the IPOPT solver is used, which implements a nonlinear primal-dual interior-point method, one of the leading techniques for large-scale nonlinear optimization.


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