• Management Science and Financial Engineering
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• v.1 no.1
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• pp.39-66
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• 1995

This article presents a new model called the periodic square wave(PSW) to describe the material flow of periodic processes involving an intermediate buffer. The material flows into and out of the intermediate buffer are assumed to be periodic square shaped. By using this model, It is proved that the classical economic lot size model with finite supply rate, the so-called EPQ model, can be applicable to the arbitrary periodic demand case. This new model relaxes the original assumption of the constant demand. It is shown, as a unique application example, that the explicit solution for determining both upstream and downstream economic lot size can be obtained with the aid of the PSW model. The PSW model provides more accurate information on analyzing the inventory and production system than the classical approach, without losing simplicity and increasing the computational burden.

• Journal of Korean Society for Quality Management
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• v.30 no.3
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• pp.53-65
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• 2002

This paper studies an economic manufacturing quantity (EMQ) model with two types of failures and planned preventive maintenance of the production facility. One is a type I (major) failure which should be corrected by a failure maintenance and the other is a type H (minor) failure which can be minimally repaired without interrupting the production run. The objective is to determine the lot size and preventive replacement policy minimizing the long-run expected cost per unit time. We consider a control policy with a constant production lot size and preventive maintenance after completing n production runs. It is assumed that both preventive and failure maintenance times are random and the demand arriving during a stock-out period is lost. An expression for the expected cost per unit time is obtained in the general case. A special case is discussed and numerical results are provided.

• Journal of Korean Society for Quality Management
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• v.16 no.2
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• pp.82-91
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• 1988

This study is concerned with the development of the economic sampling inspection plan when it is possible to carry out a nondestructive screening inspection for the rejected lots by substitutive characteristics closely related to the original quality characteristic. It is assumed that the probabilities of those errors depend linearly on the fraction defective of the process. The inspection policies considered are as follows: take a random sample of size n from the lot of size N and perform a destructive test on the sample. If the number of the defective items is not greater than a critical number C, accept the lot. Expected cost functions are obtained when the process average can be considered to follow a beta distribution and the way of finding the optimal values of (n, c) is to be explored.

• IE interfaces
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• v.12 no.3
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• pp.468-479
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• 1999

Lean production system can be defined as customer(product)-oriented production system with small lot size and flow-shop layout based on the JIT(Just-in-time) principles. In this paper, we introduce a case example of implementation of the Lean product ion system for manufacturing line of electronic component which has both machine processes and manual jobs. We also investigate the issues of implementing the Lean production system with the viewpoints of layout design scheme and JIT management rules. In the layout design, we propose the cell-line which has flow-shop layout with small lot size. In the management rules, the superior cell rule is applied in order to boost the needs of kaisen up. As the results of implementing the Lean production system, production lead time is decreased from 5 days to 1.5 days and also productivity and quality level arc surprisingly increased.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.2035-2036
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• 2006

Most industrial robot have not load control box because of robot's weight and volume. A robot is connected to its control box by cables. and then there are a lot of problem for transfer, management and operation of robot. Now a day, A lot of control module are made small size by development of electronics part technology and control technology and they are developing as embedded and loading system. For that, control module and its servo system for a mobile robot is developed. they are small size in comparison with conventional products.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.453-454
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• 2010

Statical analysis for determination of LOT size was performed to make inspection standards on concrete pavement site applied correspondingly to KS Q 0001. As a result, minimum sampling frequency of strength inspection to certify the required flexural strength was analysed once for each $300m^3$ or once per day, nor less than.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.7
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• pp.750-755
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• 2014

Product shortage which causes backordering and/or lost sales cost is very popular in chemical industries, especially in commodity polymer business. This study deals with backordering cost in the supply chain optimization model under the framework of process-inventory network. Classical economic order quantity model with backordering cost suggested optimal time delay and lot size of the final product delivery. Backordering can be compensated by advancing production/transportation of it or purchasing substitute product from third party as well as product delivery delay in supply chain network. Optimal solutions considering all means to recover shortage are more complicated than the classical one. We found three different solutions depending on parametric range and variable bounds. Optimal capacity of production/transportation processes associated with the product in backordering can be different from that when the product is not in backordering. The product shipping cycle time computed in this study was smaller than that optimized by the classical EOQ model.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.4 no.5
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• pp.11-14
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• 1981

This study intends to decide the economic sample size based on the cost of sampling Inspection for destructive testing. The marginal percent defective is used as the lot tolerance percent defective (LTPD), and the Newton's iterative method is adopted to calculate the optimum sample size(n), given by the consumer's risk($\beta$ - risk) and the acceptance number(c).

• Proceedings of the Safety Management and Science Conference
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• 2000.05a
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• pp.77-86
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• 2000

This paper deals with the problem of determining the retailer's optimal price and order size under the condition of order-size-dependent delay in payments. It is assumed that the length of delay is a function of the retailer's total amount of purchase. The constant price elasticity demand function is adopted which is a decreasing function of retail price. Investigation of the properties of an optimal solution allows us to develop an algorithm whose validity is illustrated through an example problem.

• Korean Institute of Interior Design Journal
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• no.38
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• pp.116-124
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• 2003

The purpose of this study was provide basic data for homemakers' housing notion according to unit size in apartment. This study was conducted by questionnaires that concerning about middle class homemakers whom they lived in Bundang. The results of this study were as follows; 1) In research on the homemakers' general quality, 20pyung unit size was alike 30pyung unit size and 40pyung unit size was similar to 50pyung unit size. 2) Homemakers' perception according to unit size in apartment was various; (a) 20pyungㆍ30pyung unit size-effective household space for husbands' participation, more sports facilities, parking lot space etc. (b) 40pyungㆍ50pyung unit size-homemakers' individual room, ordering and variable unit plan etc. 3) In research on the homemakers' needs, each of unit size was analogous to storage, common facility, new design and new housing form etc.