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Variations of the classical Vehicle Routing Problem (VRP) consider clients that require pick-up and delivery service, simultaneously or not. Each variation corresponds to a specific routing policy, applicable to a given context. Although several routing problems of this nature are defined in the literature, there are relationships among them that define one problem as a particular case of another,...
This work proposes a method to solve a locomotive selection problem in a gold mine situated near Belo Horizonte (Brazil) using queuing theory and simulation methods. This procedure also takes into account technical characteristics of the trains that operate in underground mines thus selecting a locomotive that is most appropriate for a specific operational environment.
This paper describes a computer-aided custom designed support system to reduce milk transportation costs. The model was developed in co-operation with Uruguay National Cooperative of Milk Producers (Conaprole). The vehicle routing model contains three inter-communicating parts: a) a Geographic Information System (GIS), b) external and internal interfaces, and c) a Vehicle Routing solver that includes...
Two classes of problems are considered within the framework of a general approach to solve optimisation problems with fuzzy coefficients, referred to as <X, M> and <X,R> models in the literature. This paper is concerned with the latter and proposes an approach which replaces the initial problem by a set of associated mutually interrelated models. To reduce the decision uncertainty region,...
A new approach for forecasting and detecting emergencies by condition monitoring, based on the bifurcation analysis, is proposed using an experimental study of pulse energy conversion systems. The proposed approach uses online monitoring of “dangerous” bifurcation boundaries in a system parameter space. It enables it to identify “dangerous” bifurcation situations potentially associated with emergencies...
The traditional method to construct Geographic Information System (GIS) is to first scan published maps, then undertake the important and difficult step to digitize maps data. The latter is a time consuming and labour intensive procedure. In this paper, a modeling method based on neural networks is proposed to extract road and other geographic Information from high-resolution satellite images to construct...
This paper introduces fuzziness in prioritized goal programming formulation of an unbalanced transportation problem with budgetary constraints keeping budget on the first priority. An efficient computational procedure is given for solving such model. The solution procedure is illustrated with a numerical example. We also compare our results with those obtained by Singh V. N. [9] for different priority...
In this paper we consider an M/M/c interdependent queueing model with controllable arrival rates. The steady state solutions and the system characteristics are derived and analyzed for this model. The results we have obtained are merely the extension of those for M/M/1 interdependent queueing model with controllable arrival rates discussed by K. Srinivasa Rao, P.Srinivasa Rao, T.Shobha [3]. The corresponding...
A closed form equation is developed for system reliability of an M-out-of-N warm standby system with R repairmen to repair the failed components. Under appropriate restriction, the equation reduces to system reliability of M-out-of-N warm standby system without repairmen. Also, the results of hot and cold standby systems without repairmen are derived as particular cases.
Past research in the area of inventory modeling has yielded a variety of inventory models that suit several situations. Yet there is a scope as well as a need to make a model more general and more flexible. In this paper, we develop an ordering cum pricing policy for a periodic review inventory system in which the demand is declining with time, and depends on the selling price, in terms of the price...
We have considered a multi-level linear programming problem, namely three-level linear programming problem (TLPP) and applied Karush-Kuhn-Tucker (KKT) transformation method to obtain the solution of the system. In the KKT transformation method, the lower level decision making problem is converted into the constraints of the higher level decision making problem. We have taken into account the non-negativity...
In this paper relationships between the solutions of the Variational- Like and Pre-Variational Problems with those of the Constrained Mathematical Programming Problems have been established. Sufficient conditions are obtained for Kuhn-Tucker points to be minima of the Constrained Mathematical Programming Problem, through the solutions of the Pre-Variational Problems.
In this paper, a deterministic inventory model is developed for deteriorating items with stock-dependent demand and shortages. The conditions of permissible delay in payments are also taken into consideration. In addition, the shortages are neither completely backlogged nor completely lost assuming the backlogging rate to be inversely proportional to the waiting time for the next replenishment. Numerical...
Two Non-homogeneous poisson process (NHPP) models are introduced which incorporate the impact of test effort and imperfection in debugging. In model I it is assumed that every time an error is rectified there is a probability p that the rectification is imperfect and the error may precipitate at a later stage. This p is assumed to be same for all the errors. In model II we classify errors into two...
We consider an unconstrained minimization reformulation of the complementarity problem (CP) on Rn. The merit function introduced here is by using Fukushima’s regularized gap function and it is proved that the global minimizers coincide with the solution of CP. This paper also shows that even if (Ψ1, Ψ2) — monotone generalizes the classical definition of monotone, there is no guarantee on the existence...
In a multi-stage production/inventory system, customer service level is a function of the service levels at individual stages. The objective of a multi-stage system can be defined in terms of determining the stage-specific service levels, which minimize the total cost of the system subject to achieving a desired customer service level. The literature available so far discusses the service level perspective...
Structural redundancies in large scale mathematical programming models are nothing uncommon and large scale Linear Programming Problems (LPP) are no exception. The presence of such embedded redundancies is hardly disputed and can play havoc with LP solution procedures and greatly hamper the solution effort. It is necessary to understand the modelling implications of these embedded redundancies as...
The special case of uncapacitated transhipment problem considered in this paper is a minimum cost flow problem with infinite arc capacities and flow takes place in stages i.e. from plants, goods move to warehouses, and from warehouses they move to the markets. This problem can also be posed as a simple transportation problem for which Sharma and Sharma [9] have given an O(cn2) procedure which obtains...
Efficiency models of data envelopment analysis are extended here to include the transition from micro to macro levels, where the latter provides an overall measure of market efficiency. The dynamics of the entry and exit behavior, the impact of demand uncertainty on capacity utilization and the specification of the dynamic cost frontier are analyzed in some detail and empirically illustrated in terms...
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