• 한국품질경영학회:학술대회논문집
• /
• 한국품질경영학회 1998년도 The 12th Asia Quality Management Symposium* Total Quality Management for Restoring Competitiveness
• /
• pp.277-286
• /
• 1998

This paper investigates the problem of determining optimal replacement policies for equipment subject to failures with cyclic rates. In many situations, the system failures depend on the operating environmental conditions that vary on time, usually with periodical manners. We use nonhomogeneous Poisson processes whose rate functions exhibit cyclic behavior as well as a long-term evolutionary trend to model the stochastic process of the failures when the rate of occurrence of the failures varies periodically, for example from day to day or between seasons. In this study, we compare optimal policies under the nonhomogeneous process with/without a cyclic component in the failure rate function. The analytical results for various situations are presented along with numerical examples using simulated data.

• 한국산업정보학회:학술대회논문집
• /
• 한국산업정보학회 1999년도 춘계학술대회 발표논문집
• /
• pp.145-153
• /
• 1999

We consider a Direct Input Output Manufacturing System(DIOMS) which has a munber of machine centers placed along a built-in Automated Storage/Retrieval System(AS/RS). The Storage/Retrieval (S/R) machine handles parts placed on pallets for the machine centers located at either one or both sides of the As/Rs. This report studies the operational aspect of DIOMS and determines the optimal operating policy by combining computer simulation and genetic algorithm. The operational problem includes: input sequencing control, dispatching rule of the S/R machine, machine center-based part type selection rule, and storage assignment policy. For each operating policy, several different policies are considered based on the known research results. In this report, using the computer simulation and genetic algorithm we suggest a method which gives the optimal configuration of operating policies within reasonable computation time.

• 대한산업공학회지
• /
• 제26권2호
• /
• pp.81-87
• /
• 2000

As for M/G/1 queueing system, we use various control policies, with which we can optimize the system. Up to now the most widely adopted policies are N-Policy, T-Policy, D-Policy, and so on. The existing researches are largely concerned to find an optimal operation condition or to optimize the system under single policy in M/G/1 system. There are, however, few literatures dealing with multiple control policies at once to enhance the flexibility of the model. In this study, we consider M/G/1 system adopting N-Policy and T-Policy simultaneously. If one of two conditions is satisfied, then, the server starts the service. We call this Min(N,T)-Policy. We find the probability distribution of the number of customers and mean waiting time in steady state and derive a cost function. Next, we seek the $N^*$, optimal threshold under various N values. Finally, we reveal the characteristics of cost function.

• 대한산업공학회지
• /
• 제23권2호
• /
• pp.403-420
• /
• 1997

In this paper, we examine the effect of production uncertainty to production control policies. First, we examine two famous production control policies, namely, MRP and JIT from the view point of shop floor control perspective, and analyze the differences between them due to demand fluctuations and activity time variations. Second, we conduct simulation studies on MRP and JIT to draw out the effects of demand fluctuations and activity time variations. Demand fluctuations are further classified into demand lumpiness and demand irregularity. And, activity time variations are further classified into stationary time variations and non-stationary time variations. Experimental results show that, in terms of demand fluctuations, MRP is affected by demand lumpiness, but JIT by demand irregularity. And we also see that both MRP and JIT are influenced by stationary time variation with respect to activity time variations.

• 산업경영시스템학회지
• /
• 제36권3호
• /
• pp.25-33
• /
• 2013

This study investigates the current status of the green growth policies of Korean public corporations and proposes some potential improvement ideas. A set of twenty global green trends are first elicited by using classified macro trends of environmental changes. The green trends are categorized into four key issues based on which domestic and international research efforts are compared. The management performance reports of Korean public corporations are then throughly analyzed to evaluate the validity of their strategic green tasks in relevant to the global green trends. Finally, we suggest some potential government policies for enhancing the existing green growth businesses of public corporations.

• 대한산업공학회지
• /
• 제12권1호
• /
• pp.31-41
• /
• 1986

In this paper, an integrated production inventory model is developed for two products on a single facility in which the raw materials are fed to the production system as required at the facility. The aim is to determine simultaneously the optimal production schedule for two products and the optimal procurement policies for the raw materials in a way that minimizes the total variable cost of the production system. The production schedule for the more frequently set-up product is formulated by the method of equal or unequal lot sizes. For the model developed, we present a computational scheme of finding the optimal policies and carry out sensitivity analysis through example problem.

• 한국경영과학회:학술대회논문집
• /
• 한국경영과학회 2006년도 추계학술대회
• /
• pp.323-326
• /
• 2006

We investigate pricing and ordering policies in a supply chain consisting of a single manufacturer and a single retailer. Demand at the retailer depends on the retail price and is assumed to be constant over time for the fixed price. The retailer places orders according to an EOQ policy and the manufacturer produces the order quantity according to a lot-for-lot policy. The retailer and the manufacturer cooperates each other to maximize the average profit for the supply chain. A mathematical model is presented and a solution procedure is developed to determine the optimal retail price and order quantity.

• 무역상무연구
• /
• 제53권
• /
• pp.155-180
• /
• 2012

Korea has the plans to improve nation and corporate global competitiveness through reducing the logistics costs. Ministry of Knowledge Economy, as the government department of in charge of the plan, establish industrial logistics policies in 2002 and 2007 and it's about time to set up the third industrial logistics policy in 2012. There are new trends for the logistics environment in terms of environment-friendly logistics, logistics securities, win-win collaboration etc. This study propose some harmonious plans between logistic productivity and the new trends in the field of logistics. For the purpose of that, we have evaluated the second industrial logistics policy. We propose the vision and objectives of the new industrial logistics policy. The vision is entering the line of industrial logistics developed nations through the sustainable logistics innovation, and the objects are smart & green logistics, win-win collaboration, lead the new logistics trends etc. We also propose the set the system and rules to push promote the new plan. In addition, industrial logistics is the new terminology setting out use by Ministry of Knowledge Economy.

• 한국안전학회지
• /
• 제28권1호
• /
• pp.6-11
• /
• 2013

In this study, the effect of damping and elastic nature on the control performance of a safety budget-industrial accident rate model in Korea is examined first. The effectiveness of such dynamic model in establishing safety policies is shown with a simple proportional-integral(PI) feedback control mechanism. Control performance of the safety system model is explained in view of maximizing the effect of IAPF and minimizing the absolute amount of IAFP. Control performance is then evaluated and proved to be effective to prevent and reduce the industrial accidents. Implications in feedback control of a safety system model suggested to optimization of safety policies are also explored. Without proper restructuring of the safety system, it would not be possible to hit the target industrial accident rate. Even if the control objective is met, the amount of industrial accident prevention fund required to reduce the industrial accident rate from the current level to the target level would be far beyond the social consensus.

• 한국산업융합학회 논문집
• /
• 제22권6호
• /
• pp.729-737
• /
• 2019

The world is now going through the era of the Fourth Industrial Revolution. Major global economies, including the United States, Germany, Japan and China, are fostering industries related to the fourth industrial revolution with policies and investments. South Korea is also setting up its fourth industrial revolution committee under the president, expanding policies and investment to foster industries related to the fourth industrial revolution, and increasing investment in research and development. Accordingly, government and private investment in industries and technologies related to the Fourth Industrial Revolution is made extensively around the world, and many related industries and technologies are being developed. In this paper, we will look into the status and problems of Advanced Concept Technology Demonstration projects that can quickly and easily introduce technologies related to the fourth industrial revolution in the private sector where many developments are taking place, and present the direction of development.