Optimal location of dwell points in a single loop AGV system with time restrictions on vehicle availability

Since the workload of a manufacturing system changes over time, the material handling equipment used in the facility will be idle at certain time intervals to avoid system overload. In this context, a relevant control problem in operating an automated guided vehicle (AGV) system is where to locate idle vehicles. These locations, called dwell points, establish the response times for AVG requests. In this article, a dynamic programming algorithm to solve idle vehicle positioning problems in unidirectional single loop systems is developed to minimize the maximum response time considering restrictions on vehicle time available to travel and load/unload requests. This polynomial time algorithm finds optimal dwell points when all requests from a given pick-up station are handled by a single AGV. The proposed algorithm is used to study the change in maximum response time as a function of the number of vehicles in the system.Dynamic programming Automated guided vehicles Dwell points

A COMPOUNDING ALGORITHM FOR 1-FAULT TOLERANT BROADCAST NETWORKS

This theoretical paper presents a new construction algorithm for sparse 1-fault tolerant minimal broadcast networks (1-FTMBNs). To construct a large 1-FTMBN with the algorithm, identical nodes in copies of a broadcast network that is not fault tolerant are connected according to the edge structures of two known 1-FTMBNs with a special property. In most cases, computational results with this algorithm produce the best-known bounds on the cardinalities of the edge sets of the sparsest 1-FTMBNs with an odd number of nodes.Construction algorithm, minimal broadcast network, fault tolerant network, broadcast protocol

Binary linear programming models for robust broadcasting in communication networks : [data]

Output files showing optimal network configurations. Abstract from related article: Broadcasting is an information dissemination process in communication networks whereby a message, originated at any node of a network, is transmitted to all other nodes of the network. In c-broadcasting, each node having the message completes up to c transmissions to its neighbors over the communication lines in one time unit. In a k-fault tolerant broadcast network, the broadcasting process can be accomplished even if k communication lines fail. This paper presents innovative binary linear programming formulations to construct c-broadcast graphs, k-fault-tolerant broadcast graphs, and their time-relaxed versions. The proposed mathematical models are used to generate eight previously unknown minimum c-broadcast graphs, new upper bounds for eleven other instances of the c-broadcast problem, and over 30 minimum k-fault-tolerant c-broadcast graphs. The paper also provides a construction method to produce an upper bound for an infinite family of k-fault-tolerant c-broadcast graphs