Loading...
Search for:
capacity-constraints
0.007 seconds
Generating dependent random variables over networks
, Article 2011 IEEE Information Theory Workshop, ITW 2011 ; 2011 , Pages 698-702 ; 9781457704376 (ISBN) ; Anantharam, V ; Sharif University of Technology
Abstract
In this paper we study the problem of generation of dependent random variables, known as the coordination capacity [4], [5], in multiterminal networks. In this model m nodes of the network are observing i.i.d. repetitions of X (1), X (2),⋯, X (m) distributed according to q(x (1),⋯, x (m)). Given a joint distribution q(x (1),⋯,x (m), y (1), ⋯, y (m)), the final goal of the i th node is to construct the i.i.d. copies of Y (i) after the communication over the network where X (1), X (2),⋯, X (m), Y (1), Y (2),⋯, Y (m) are jointly distributed according to q(x (1), , x (m), y (1),⋯,y (m)). To do this, the nodes can exchange messages over the network at rates not exceeding the capacity constraints...
Solving Traffic Assignment Problem with Side Constraints
, M.Sc. Thesis Sharif University of Technology ; Zokaei Aashtiani, Hedayat (Supervisor)
Abstract
In recent years, traffic assignment problem with side constraints has been considered because of the importance of transportation supply management. Side constraints which are appeared due to imposing the traffic control policies are usually represented in form of link, node or district capacity constraints. Although link capacity constraint has been extensively studied, only a few papers on the other types of constraints such as capacity constraint on inflow to a district of city exist in the literature. In this research a method based on dynamic penalty function (DPF) is presented to solve traffic assignment problem with side constraints. Solution algorithm has been coded in a programming...
A constraint-based performance comparison of hypercube and star multicomputers with failures
, Article 19th International Conference on Advanced Information Networking and Applications, AINA 2005, Taipei, 28 March 2005 through 30 March 2005 ; Volume 1 , 2005 , Pages 841-846 ; 1550445X (ISSN); 0769522491 (ISBN); 9780769522494 (ISBN) ; Sarbazi Azad, H ; Sharif University of Technology
2005
Abstract
Many theoretical studies have compared the hypercube and star graphs from a graph theoretical viewpoint, under structural and algorithmic properties. None of these studies have, however, considered real working conditions and implementation constraints. In this paper, the hypercube and star graphs are compared in view of fault tolerance and technological implementation constraints. In order to realize a fair comparison, we use the unsafely-vector fault tolerant routing algorithm, recently introduced in [1] and [2], for the hypercube and star graph. Under two implementation constraints, namely constant bisection bandwidth and constant node pin-out, we have compared the performance of the two...
The Assortment Planning Problem Consisting Capacity Constraint and Discount Policy with Metahuristic Solution Methods
, M.Sc. Thesis Sharif University of Technology ; Shavandi, Hassan (Supervisor)
Abstract
Assortment planning considers the problem of product classification in order to maximize the profit by considering related constraints. Integrating the assortment planning with inventory management plays an essential role in retail optimization. The importance of integrating these problems is related to customer behavior in substituting the products in case of shortage. The customer checks the availability of products in order of his/her priorities and buys a product if available otherwise leaving the store without purchase if he/she cannot find a product according to his/her preferences. Customer preferences are modeled through the definition of consumer types, where a type is a ranking of...
Mass Transport Between Stationary Random Measures
, Ph.D. Dissertation Sharif University of Technology ; Alishahi, Kasra (Supervisor) ; Haji Mirsadeghi, Mir-Omid (Co-Advisor)
Abstract
Given two stationary random measures on Rd, we study transport kernels between them that are translation-covariant. We will provide an algorithm that constructs such a transport kernel, with some assumption on their intensities. As a result, this algorithm can be used to construct the Palm version of an ergodic random measure by simply applying a (random) translation and vice versa, to reconstruct the distribution of the random measure from its Palm distribution. Given realizations of the two random measures, our algorithm provides its result in a deterministic way. The existence of such transport kernels is proved in [18] in an abstract way. Nevertheless, there has been tremendous interest...
Rapid Transit Network Design For Maximizing Acceptable Transit Coverage
,
Ph.D. Dissertation
Sharif University of Technology
;
Shafahi, Yousef
(Supervisor)
Abstract
Designing a rapid transit network which is capable of providing a convenient coverage for passengers is studied in thisdoctoral thesis. First, a mathematical model of rapid transit network design which is a mixed integer program is presented (C_RTND). Objective function of the model is maximization of acceptable transit coverage and the model is capable of considering different rapid transit technologies. Furthermore, for each technology capacity constraint is considered in the model. Second, a heuristic algorithm is developed and used to solve the proposed model. The algorithm consists of 3 main parts: candidate line generation, network evaluation and a search algorithm for selecting a good...
An integrated simulation model and evolutionary algorithm for train timetabling problem with considering train stops for praying
, Article Proceedings - Winter Simulation Conference ; 2012 ; 08917736 (ISSN); 9781467347792 (ISBN) ; Sajedinejad, A ; Mardani, S ; Mohammadi, K. S. A. R. M ; Assoc. Comput. Mach.: Spec. Interest Group Simul. (ACM/SIGSIM); Institute of Industrial Engineers (IIE); Inst. Oper. Res. Manage. Sci.: Simul. Soc. (INFORMS-SIM); The Society for Modeling and Simulation International (SCS); Arbeitsgemeinschaft Simulation (ASIM) ; Sharif University of Technology
2012
Abstract
This paper presents a simulation-based optimization approach for railway timetabling, which is made interesting by the need for trains to stop periodically to allow passengers to pray. The developed framework is based on integration of a simulation model and an evolutionary path re-linking algorithm with the capability of scheduling trains, subject to the capacity constraints in order to minimize the total waiting times. A customized deadlock avoidance method has been developed which is based on a conditional capacity allocation. The proposed look-ahead deadlock avoidance approach is effective and easy to implement in the simulation model. A case study of the Iranian Railway (RAI) is...
SIMARAIL: Simulation based optimization software for scheduling railway network
, Article Proceedings - Winter Simulation Conference, 11 December 2011 through 14 December 2011, Phoenix, AZ ; 2011 , Pages 3730-3741 ; 08917736 (ISSN) ; 9781457721083 (ISBN) ; Mardani, S ; Hasannayebi, E ; Mohammadi K., S. A. R. M ; Kabirian, A ; Sharif University of Technology
2011
Abstract
This paper presents an event-driven simulation-based optimization method for solving the train timetabling problem to minimize the total traveling time in the hybrid single and double track railway networks. The simulation approach is well applied for solving the train timetabling problems. In present simulation model, the stations and block sections of the railway network are respectively considered as the nodes and edges of the network model. The developed software named SIMARAIL has the capability of scheduling trains in large scale networks respecting the capacity constraints and infrastructure characteristics. This simulation model for railway timetabling is based on a detailed...
Solving Detour-Based Fuel Stations Location Problems
, Article Computer-Aided Civil and Infrastructure Engineering ; Volume 31, Issue 2 , 2016 , Pages 132-144 ; 10939687 (ISSN) ; Aashtiani, H. Z ; Ghamami, M ; Marco Nie, Y ; Sharif University of Technology
Blackwell Publishing Inc
Abstract
This article studies the problem of locating fuel stations to minimize the extra cost spent in refueling detours, which belongs to a class of discretionary service facility location problems. Unlike many studies of similar problems in the literature, the proposed model considers capacity constraints and compares different ways to incorporate them in the formulation. Note that ignoring the capacity constraint results in nonoptimal and unrealistic solutions. The proposed models are solved using both an off-the-shelf solver (CPLEX) and a specialized meta-heuristic method (Simulated Annealing) developed in this study. The solution methods are tested and compared in two case studies; a test...