Showing papers in "Journal of Statistics and Management Systems in 2000"
TL;DR: The generating function of the number of customers in the system and in orbit in stationary regime and the stochastic decomposition property and the problem of the optimal control of the vacation policy are obtained.
Abstract: We consider an MX /G/1 retrial queue with batch arrivals and server vacations, when the works for service and vacation tasks are arbitrary distributed. We obtain here the generating function of the number of customers in the system and in orbit in stationary regime. We also discuss stochastic decomposition property and the problem of the optimal control of the vacation policy.
21 citations
TL;DR: In this paper, the authors consider a discrete time, finite horizon problem of optimization of the financing/dividend decisions concerning a multi-period investment project and obtain the optimal levels of debt and equity capital for each period and the optimal dividend payment scheme, under various financial constraints.
Abstract: In this paper we consider a discrete time, finite horizon problem of optimization of the financing/dividend decisions concerning a multiperiod investment project. We assume that for each subperiod of a given time interval the cash movement generated by the project, the borrowing rate and the rate of return on firm’s liquidity are stochastic variables with a known distribution. Adopting an accounting point of view, we assume as objective function the expected amount of retained earnings at the end of the time horizon. Our aim is to obtain the optimal financing/dividend policy for the project in question, i.e. the optimal levels of debt and equity capital for each period and the optimal dividend payment scheme, under various financial constraints.
6 citations
TL;DR: In this article, the authors considered a modified lot size reorder point model with imperfect production process, where the unsatisfied demand is assumed to be a mixture of backorders and lost sales.
Abstract: This paper considers a modified lot size reorder point model with imperfect production process, where the unsatisfied demand is assumed to be a mixture of backorders and lost sales. It investigates the effects of investing in process quality improvement on the model. Specifically, we discuss the case where only partial information of lead time demand is known, and solve the problem by applying the minimax distribution free approach. An algorithm procedure is established to obtain the optimal lot size, reorder point and process quality level. Numerical examples are provided to illustrate the results derived.
5 citations
TL;DR: In this article, the authors proposed new ratio and product type estimators for estimating the mean of finite population using information on multi-auxiliary variables and calculated the bias and mean square error (M. S. E) of these estimators.
Abstract: This paper proposes new ratio and product type estimators for estimating the mean of finite population using information on multi-auxiliary variables. The Bias and Mean square error (M. S. E.) of these estimators are calculated. These estimators are compared for their precision with usual mean per unit, ratio and product estimators and are found to be more efficient in many practical situations.
4 citations
TL;DR: In this article, a model is presented to analyze the effect of various exogenous parameters such as the resource stock level, technical progress, and market demand on the optimal point of pollution abatement.
Abstract: Since pollution abatement activities require the consumption of resource, they can be seen as an exchange of resource for clean environment. In perspective of finite resource supply and sustainable development, a model is presented to analyze the effect of various exogenous parameters such as the resource stock level, technical progress, and market demand, etc. on the optimal point. The results reveal that (1) the society with less resource stock must take some other measures such as technology innovation to increase its production level and improve its environment, (2) the increase in production is limited by technological progress, and (3) the increase in market demand leads to the increase in production, but also make environmental quality worse.
4 citations
TL;DR: In this article, a multiobjective fractional variational control problem is considered and the Wolfe type and Mond-Weir type duality results are established under generalized (F, ρ)-convexity assumptions.
Abstract: A multiobjective fractional variational control problem is considered. Wolfe type and Mond-Weir type duality results are established under generalized (F, ρ)-convexity assumptions.
4 citations
TL;DR: In this article, the authors derive solutions that are based on the use of estimators which are functions of the estimated density function, which are consistent and can be used to determine the optimal burn-in-time.
Abstract: The determination of the optimal burn-in-time is related with the minimization of the expected costs of the manufacturing and/or the warranty. We derive solutions that are based on the use of estimators which are functions of the estimated density function. They are consistent.
3 citations
TL;DR: In this article, a linear regression model is applied to Bangladesh agricultural data to measure the agricultural output using farm size, labour, and biological-chemical as input regressors to determine to what extent the efficiency of the model is affected due to different geographical regions.
Abstract: The main objective of this study is to estimate a linear regression model for survey data and to determine to what extent the efficiency of the model is affected due to different geographical regions. The Cobb-Douglas production function is used to estimate the unknown parameters. The linear regression model is applied to Bangladesh agricultural data to measure the agricultural output using farm size, labour, and biological-chemical as input regressors.
3 citations
TL;DR: In this article, a double-ended queueing system in which either customers which arrive in a group of random size or idle servers which may also serve in batches is studied, where the arriving customers form a queue for s...
Abstract: A double ended queueing system in which either customers which arrive in a group of random size or idle servers which may also serve in batches is studied. The arriving customers form a queue for s...
3 citations
TL;DR: In this article, a dynamic optimal model of sustainable development is proposed to maximize the total present utility value of current and future generations under the consideration of environmental protection and economic growth, and the objectives of the model are to maximise the total current utility value and future future utility value.
Abstract: The purpose of this paper is to construct a dynamic optimal model of sustainable development. Under the consideration of environmental protection and economic growth, the objectives of the model are to maximize the total present utility value of current and future generations. We know that the capital is a necessary factor to develop the economy, so we consider that the capital is the only input factor for production function. To internalize the externality, the environmental protection policy is to collect the pollution tax not only from producer but also from consumer in order to be in accordance with the spirit of social justice. And the balanced budget should make the pollution tax revenue be adequate to provide the government pollution control and public expenditure. This paper applies the dynamic optimization theory to construct the model, we have descriptions of the model and also have some inferences as conclusions.
2 citations
TL;DR: In this article, the simultaneous determinations of optimal purchase timing and optimal order quantity at a purchase price discount in a generalized newsboy problem were investigated, where the distribution of the demand with a decreasing variance over the time represents the forecasting ability of the buyer.
Abstract: This paper deals with the simultaneous determinations of optimal purchase timing and optimal order quantity at a purchase price discount in a generalized newsboy problem. It is assumed that the distribution of the demand with a decreasing variance over the time represents the forecasting ability of the buyer. Thus, in addition to the well-known tradeoffs associated with stocking products under uncertain spot demand, there is an additional tradeoff associated with the purchase cost depending on the purchase timing. A model is proposed, and the solutions are interpreted and compared for some particular set of parameter values.
TL;DR: In this article, a multiobjective fractional programming problem involving invex functions is considered, using parametric approach, two types of duals and appropriate weak and strong duality theorems are established for efficient solutions by considering a sequence of equivalent single objective programming problems.
Abstract: Multiobjective fractional programming problem involving invex functions is considered. Using parametric approach, two types of duals and appropriate weak and strong duality theorems for invex and quasiinvex functions are established for efficient solutions by considering a sequence of equivalent single objective programming problems.
TL;DR: In this article, a multiobjective fractional variational control problem is considered and duality results are established under generalized (F, ρ)-convexity assumptions under Wolfe type and Mond-Weir type duality.
Abstract: A multiobjective fractional variational control problem is considered Wolfe type and Mond-Weir type duality results are also established under generalized (F, ρ)-convexity assumptions
TL;DR: In this paper, the authors compared the forecasting performance of the error correction model (ECM), the autoregressive conditional heteroscedastic (ARCH) model, the regression with ARMA error model (Reg-ARMA), and autoregression error model(Autoreg).
Abstract: The study is designed to demonstrate how the forecasting models with corrected error term can be effectively used to high performance forecasts for stock price applications. Another purpose of this study is to compare the forecasts generated by the error correction model (ECM), the autoregressive conditional heteroscedastic (ARCH) model, the regression with ARMA error model (Reg-ARMA) and the autoregressive error model (Autoreg). The accuracy of these forecasting models is measured by using the forecasting errors in a post-sample period. The results show that the forecasting performance of the ECM is the best, and the next best in Autoreg model while the worst is Reg-ARMA model.
TL;DR: In this article, the authors derived uniformly minimum variance unbiased estimators (UMVUEs) for series in scale parameter for a gamma distribution with a known shape parameter, and then obtained the UMVUE's of moments and reliability of an exponential distribution using these results.
Abstract: We derive uniformly minimum variance unbiased estimators (UMVUE’s) for series in scale parameter for a gamma distribution with a known shape parameter. We then obtain the UMVUE’s of moments and reliability of an exponential distribution using these results.
TL;DR: The (s, Q) inventory system with customer line items backordered with convex cost function is considered and a solution procedure is developed to generalize that described by Silver et al. to two decision variables.
Abstract: The aim of production management is to meet the customers’ wishes as far as possible by an optimal way. So, the customer-oriented production management becomes increasingly important with time. Based on this principle, this paper considers the (s, Q) inventory system with customer line items backordered. At first, this paper shows that the total relevant cost function is convex. Then, with the convexity, a solution procedure is developed to generalize that described by Silver et al. to two decision variables. Numerical examples are also given to illustrate the solution procedure.
TL;DR: In this article, the equality of two examinees' abilities using dichotomous two-parameter logistic model based on the item response data has been discussed and a large sample approximations are considered for the test.
Abstract: Abstract There have been lots of literature concerning estimations of examinees’ abilities, however, relatively few relates to hypothesis testing for equality of examinees’ abilities. This study first concerns tests for the equality of two examinees’ abilities using dichotomous two-parameter logistic model based on the item response data. When item parameters are all equal, exact test can be obtained which is based on the difference of two examinees’ scores. While item parameters are not all equal, large sample approximations are considered for the test. Test procedure is also extended to the situation that more than two examinees are involved. Finally, we discuss the testing for equality of a finite group of examinees’ abilities based on their item responses.
TL;DR: In this paper, the authors consider a continuous review inventory model with partial backorder rate and analyzes the effects of backorder rates as a control variable on the inventory system, through running the optimal backorder policy, the relevant inventory cost minimized to increase the competitive edge in business.
Abstract: This study considers a (Q, R) continuous review inventory model with a partial backorder rate, and analyzes the effects of backorder rate as a control variable on the inventory system. Through running the optimal backorder policy, we can have the relevant inventory cost minimized to increase the competitive edge in business. We discuss two models that are complete and partial information about the lead time demand distribution, that is, we first assume that the lead time demand follows a normal distribution, and then remove this assumption and only assume that the first and second moments of the probability distribution of lead time demand are known. For each case, we develop a procedure to find the optimal ordering policy.
TL;DR: In this article, the concept of a sublinear functional is extended to a becto-sub-linear functional, and the concepts of F-convex and generalized F-convolutional functions are extended to bectovex and generalized bectovox functions, respectively.
Abstract: In this paper, the concept of a sublinear functional is extended to a becto-sub-linear functional, and the concepts of F-convex and generalized F-convex functions are extended to bectovex and generalized bectovex functions, respectively. Next, a multiobjective programming problem, called the primal, is considered, and assuming the functions in the objectives and the constraints to be bectovex (generalized bectovex), a variety of sufficient conditions for efficient and properly efficient solutions are established. A Mond-Weir dual is introduced and the duality results relating the primal and the dual are established. Duality for a multiobjective fractional program is obtained as a special case.