• Journal of the Korean Operations Research and Management Science Society
• /
• v.26 no.4
• /
• pp.39-45
• /
• 2001

Maximum and minimum of rendom variables are frequently encountered in the stochastic modelling for various OR problems. We summarize and extend characteristics of maximum and minimum, emphasizing the case in which random variables are independent and all of them except one are distributed exponential. As an application, we derive a transform-free expression for the M/G/1 queue length distribution.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.39 no.4
• /
• pp.71-74
• /
• 2014

A new classification framework called 'support feature machine' was introduced in [2] for analyzing medical data. Contrary to authors' claim, however, the proposed method is not designed to guarantee minimizing the use of the spatial feature variables. This paper mathematically remedies this drawback and provides comments on models from [2].

• Journal of the Korean Operations Research and Management Science Society
• /
• v.14 no.1
• /
• pp.1-15
• /
• 1989

Multistate survival data with censoring often arise in biomedical experiments. In particular, a four-state space is used for cancer clinical trials. In a four-state space, each patient may either respond to a given treatment and then relapse or may progress without responding. In this four-state space, a model which combines the Markov and semi-Markov models is proposed. In this combined model, the generalized maximum likelihood estimators of the Markov and semi-Markov hazard functions are derived. These estimators are illustrated for the data collected in a study of treatments for advanced breast cancer.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.22 no.1
• /
• pp.51-58
• /
• 1997

In this paper, we propose a stochastic LP model for determining an optimal input quantity in a single-product multi-stage production system with random yields. Due to the random yields in our model, each stage of the production system can result in defective items, which can be re-processed or scrapped at certain costs. We assume that the random yield at each stage follows an independent discrete empirical distribution. Compared to dynamic programming models that prevail in the literature, our model can easily handle problems of larger sizes.

• Journal of the military operations research society of Korea
• /
• v.13 no.1
• /
• pp.28-44
• /
• 1987

This thesis presents a model to assign targets and to determine gun ammunitions required for naval surface warfare. Delivery errors of weapon systems and vulnerability of moving targets are analyzed, then probability to kill moving battle sihps is computed. A weapon-target allocation model is proposed by using the Out of Kilter technique. A model to determine ammunitions required for killing moving targets is also designed. The models are evaluated by simulation and sensitivity analysis.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.18 no.2
• /
• pp.83-103
• /
• 1993

This paper addresses an optimization problem faced by a multi-server and multi-class customer system in manufacturing facilities and service industries. This paper presents a model of an integrated problem of server allocation and customer type partitioning. We approximate the problem through two types of models to make it tractable. As soution approach, the simulated annealing heuristic is constructed based on the general simulated annealing method. Computational results are presented.

• Journal of the military operations research society of Korea
• /
• v.6 no.1
• /
• pp.103-117
• /
• 1980

Stochastic duels have been studied by Ancker, William, Bhashyam, Gafarian, Jaiswal, Singh, and others, Stochastic duels are classified in terms of factors such as kill probability, ammunition, time duration, surprise, mobility, time of flight, etc. The purpose of this paper is to summarize and analyze the models of stochastic duels that have been studied so far, and to study the effect of the factors to the win probability.

• Journal of the military operations research society of Korea
• /
• v.18 no.2
• /
• pp.96-113
• /
• 1992

A time-varying nonhomogeneous poisson process approximation of the nonexponential stochastic Lanchester model is defined and evaluated over a range of combat parameters including initial force sizes. breakpoints. and interkilling random variables. The proposed approximation is far excellent and takes much less CPU time than the existing models. The sensitivity analysis was peformed to evaluate the efficiency of the proposed model and three recommended factors are suggested to guide the combat operators.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.16 no.1
• /
• pp.97-112
• /
• 1991

This paper describes two contrasting approaches to group decision making involving multiple criteria. A compromise programming method and the analytic hierarchy process are analyzed and compared by using an illustrative example of a computer model selection problem to demonstrate their usefulness as a viable tool for group decision making. This paper further considers some extensions and modifications of there two methods for future study.

• Journal of the military operations research society of Korea
• /
• v.25 no.1
• /
• pp.37-54
• /
• 1999

In this paper, we proposed a modeling method of continuous combat simulation by using VENSIM. VENSIM is a CASE tool for developing continuous simulation. It provides a simple and flexible way of building simulation models from causal loop or influence diagram. As a case model, we developed "a prototype model of battle"incorporating infantry, artillery, air defense weapon, aircraft, and guerrilla engagement.ngagement.