Rajan Batta - Academia.edu (original) (raw)
Papers by Rajan Batta
Socio-Economic Planning Sciences
Annals of Operations Research, 2002
This paper studies a facility location problem with stochastic customer demand and immobile serve... more This paper studies a facility location problem with stochastic customer demand and immobile servers. Motivated by applications to locating bank automated teller machines (ATMs) or Internet mirror sites, these models are developed for situations in which immobile service facilities are congested by stochastic demand originating from nearby customer locations. Customers are assumed to visit the closest open facility. The objective of this problem is to minimize customers' total traveling cost and waiting cost. In addition, there is a restriction on the number of facilities that may be opened and an upper bound on the allowable expected waiting time at a facility. Three heuristic algorithms are developed, including a greedy-dropping procedure, a tabu search approach and an ε-optimal branch-and-bound method. These methods are compared computationally on a bank location data set from Amherst, New York.
Computers & Operations Research, 2002
Computers & Operations Research, 2003
In this paper, we study a budget constrained location problem in which we simultaneously consider... more In this paper, we study a budget constrained location problem in which we simultaneously consider opening some new facilities and closing some existing facilities. Motivations for this problem stem from applications where, due to a change in the distribution of customer demand, the existing facility system no longer provides adequate service. The objective is to minimize the total weighted travel
Computers & Operations Research, 2002
... location models have been relatively few. In the two papers by Beasley and Chu [8] and Lorena... more ... location models have been relatively few. In the two papers by Beasley and Chu [8] and Lorena and de Souza-Lopez [9], the authors have focussed on the application of GAs to set covering problems. For location models as such ...
Transportation Research Part C-emerging Technologies, 2000
Shipping hazardous material (hazmat) places the public at risk. People who live or work near road... more Shipping hazardous material (hazmat) places the public at risk. People who live or work near roads commonly traveled by hazmat trucks endure the greatest risk. Careful selection of roads used for a hazmat shipment can reduce the population at risk. On the other hand, ...
Operations Research Letters, 1993
ABSTRACT This paper presents work performed to address design and operational control issues for ... more ABSTRACT This paper presents work performed to address design and operational control issues for an Automated Guided Vehicle (AGV) based material handling system. Various design issues connected with flow path design, such as traffic flow along the guide paths, location and representation of intersections, buffers, pickup and dropoff points, are outlined. A network representation of the AVG system (AGVS) is presented. Operational control factors, such as demand selection and assignment, route planning and traffic management, idle AGV positioning, and AGV characteristics, are addressed. In particular, the performance of six demand selection policies, four demand assignment policies, and two idle AGV positioning policies are outlined. A very effective route-generation technique that provides conflict-free routes for multiple AGVs with varying speeds is presented. A large-scale simulation of a dynamic batch type manufacturing system to test the feasibility of the proposed scheme for real time control of AGVs and to determine the effect of several factors on several performance measures is presented. Our findings indicate that performance is significantly affected by vehicle speed, number of vehicles, demand arrival interval, idle AGV positioning, and the demand selection and assignment policy in use.
Socio-economic Planning Sciences, 1997
This paper presents an analytical approach to the tactical question: ‘What level of enforcement o... more This paper presents an analytical approach to the tactical question: ‘What level of enforcement over time allows one to eliminate a street market for illicit drugs while expanding the least possible total effort?’ The analysis is done in the context of Caulkins' model [6] which predicts the rate of change of dealers as a function of enforcement level and several
Transportation Science, 1989
ABSTRACT
Computers & Operations Research, 1990
ABSTRACT This paper examines the problem of finding the shortest path on a network subject to “eq... more ABSTRACT This paper examines the problem of finding the shortest path on a network subject to “equity” constraints. A Lagrangean dual bounding approach is utilized, which relaxes the “complicating constraints” of the problem. After solving the Lagrangean dual, the duality gap is closed by finding the t shortest paths with respect to the Lagrangean function. Both looping and loopless paths are considered. A quick-and-dirty heuristic procedure is also suggested. We report a sampling of our computational experiences with the model.
Transportation Science, 1991
ABSTRACT
European Journal of Operational Research, 1996
Operations Research, 1993
ABSTRACT Automated guided vehicles (AGVs) are a highly sophisticated and increasingly popular typ... more ABSTRACT Automated guided vehicles (AGVs) are a highly sophisticated and increasingly popular type of material handling device in flexible manufacturing systems. This paper details solution methodologies for the static routing problem in which demand assignment of the AGVs are known; the focus is to obtain an implementable solution within a reasonable amount of computer time. The objective is to minimize the makespan, while routing AGVs on a bidirectional network in a conflict-free manner. This problem is solved via column generation. The master problem in this column generation procedure has the makespan and vehicle interference constraints. Columns in the master problem are routes iteratively generated for each AGV. The subproblem is a constrained shortest path problem with time-dependent costs on the edges. An improvement procedure is developed to better the solution obtained at the end of the master-subproblem interactions. Several methods of iterating between the master and subproblem are experimented with in-depth computational experiments. Our empirical results indicate that the procedure as a whole usually generates solutions that are within a few percent of a proposed bound, within reasonable computer time.
Operations Research, 1990
In this paper, we develop and analyze a model to generate an equitable set of routes for hazardou... more In this paper, we develop and analyze a model to generate an equitable set of routes for hazardous material shipments. The objective is to determine a set of routes that will minimize the total risk of travel and spread the risk equitably among the zones of the ...
Socio-economic Planning Sciences, 1993
Transportation Science, 1988
Socio-Economic Planning Sciences
Annals of Operations Research, 2002
This paper studies a facility location problem with stochastic customer demand and immobile serve... more This paper studies a facility location problem with stochastic customer demand and immobile servers. Motivated by applications to locating bank automated teller machines (ATMs) or Internet mirror sites, these models are developed for situations in which immobile service facilities are congested by stochastic demand originating from nearby customer locations. Customers are assumed to visit the closest open facility. The objective of this problem is to minimize customers' total traveling cost and waiting cost. In addition, there is a restriction on the number of facilities that may be opened and an upper bound on the allowable expected waiting time at a facility. Three heuristic algorithms are developed, including a greedy-dropping procedure, a tabu search approach and an ε-optimal branch-and-bound method. These methods are compared computationally on a bank location data set from Amherst, New York.
Computers & Operations Research, 2002
Computers & Operations Research, 2003
In this paper, we study a budget constrained location problem in which we simultaneously consider... more In this paper, we study a budget constrained location problem in which we simultaneously consider opening some new facilities and closing some existing facilities. Motivations for this problem stem from applications where, due to a change in the distribution of customer demand, the existing facility system no longer provides adequate service. The objective is to minimize the total weighted travel
Computers & Operations Research, 2002
... location models have been relatively few. In the two papers by Beasley and Chu [8] and Lorena... more ... location models have been relatively few. In the two papers by Beasley and Chu [8] and Lorena and de Souza-Lopez [9], the authors have focussed on the application of GAs to set covering problems. For location models as such ...
Transportation Research Part C-emerging Technologies, 2000
Shipping hazardous material (hazmat) places the public at risk. People who live or work near road... more Shipping hazardous material (hazmat) places the public at risk. People who live or work near roads commonly traveled by hazmat trucks endure the greatest risk. Careful selection of roads used for a hazmat shipment can reduce the population at risk. On the other hand, ...
Operations Research Letters, 1993
ABSTRACT This paper presents work performed to address design and operational control issues for ... more ABSTRACT This paper presents work performed to address design and operational control issues for an Automated Guided Vehicle (AGV) based material handling system. Various design issues connected with flow path design, such as traffic flow along the guide paths, location and representation of intersections, buffers, pickup and dropoff points, are outlined. A network representation of the AVG system (AGVS) is presented. Operational control factors, such as demand selection and assignment, route planning and traffic management, idle AGV positioning, and AGV characteristics, are addressed. In particular, the performance of six demand selection policies, four demand assignment policies, and two idle AGV positioning policies are outlined. A very effective route-generation technique that provides conflict-free routes for multiple AGVs with varying speeds is presented. A large-scale simulation of a dynamic batch type manufacturing system to test the feasibility of the proposed scheme for real time control of AGVs and to determine the effect of several factors on several performance measures is presented. Our findings indicate that performance is significantly affected by vehicle speed, number of vehicles, demand arrival interval, idle AGV positioning, and the demand selection and assignment policy in use.
Socio-economic Planning Sciences, 1997
This paper presents an analytical approach to the tactical question: ‘What level of enforcement o... more This paper presents an analytical approach to the tactical question: ‘What level of enforcement over time allows one to eliminate a street market for illicit drugs while expanding the least possible total effort?’ The analysis is done in the context of Caulkins' model [6] which predicts the rate of change of dealers as a function of enforcement level and several
Transportation Science, 1989
ABSTRACT
Computers & Operations Research, 1990
ABSTRACT This paper examines the problem of finding the shortest path on a network subject to “eq... more ABSTRACT This paper examines the problem of finding the shortest path on a network subject to “equity” constraints. A Lagrangean dual bounding approach is utilized, which relaxes the “complicating constraints” of the problem. After solving the Lagrangean dual, the duality gap is closed by finding the t shortest paths with respect to the Lagrangean function. Both looping and loopless paths are considered. A quick-and-dirty heuristic procedure is also suggested. We report a sampling of our computational experiences with the model.
Transportation Science, 1991
ABSTRACT
European Journal of Operational Research, 1996
Operations Research, 1993
ABSTRACT Automated guided vehicles (AGVs) are a highly sophisticated and increasingly popular typ... more ABSTRACT Automated guided vehicles (AGVs) are a highly sophisticated and increasingly popular type of material handling device in flexible manufacturing systems. This paper details solution methodologies for the static routing problem in which demand assignment of the AGVs are known; the focus is to obtain an implementable solution within a reasonable amount of computer time. The objective is to minimize the makespan, while routing AGVs on a bidirectional network in a conflict-free manner. This problem is solved via column generation. The master problem in this column generation procedure has the makespan and vehicle interference constraints. Columns in the master problem are routes iteratively generated for each AGV. The subproblem is a constrained shortest path problem with time-dependent costs on the edges. An improvement procedure is developed to better the solution obtained at the end of the master-subproblem interactions. Several methods of iterating between the master and subproblem are experimented with in-depth computational experiments. Our empirical results indicate that the procedure as a whole usually generates solutions that are within a few percent of a proposed bound, within reasonable computer time.
Operations Research, 1990
In this paper, we develop and analyze a model to generate an equitable set of routes for hazardou... more In this paper, we develop and analyze a model to generate an equitable set of routes for hazardous material shipments. The objective is to determine a set of routes that will minimize the total risk of travel and spread the risk equitably among the zones of the ...
Socio-economic Planning Sciences, 1993
Transportation Science, 1988