• 한국경영과학회지
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• 제21권3호
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• pp.143-157
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• 1996

This paper addresses the effects of an imperfect production process on the optimal production quantity and quality inspection policies. The system is assumed to deteriorate during the production process. The result are either the production of a number of defective items or the breakdown of the production meachine. A simple rule has been suggested to determine whether multiple quality in spection is workth or not. Furthermore, when multiple inspection policy is adopted, the optimal in spection schedule is shown to be equally spaced throughout the production cycle. Exact solution and approximation of the optimal production quantity and approximation of the optimal number of inspection are provided. Finally , to better understand the model of this paper, comparisons between this model and classical EMQ model are provided.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2006년도 추계학술대회
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• pp.391-402
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• 2006

Most previous studies considering inventory models for imperfect quality assumed that defective items could be completely detected by inspection and fixed before delivery to customers. This makes it difficult to adopt their research results to practice. This study reduces the assumption of perfect inspection, and presents an inventory model considering reverse logistics caused by imperfect inspection. System dynamics model is used to describe complex and dynamic problem and to show the effect of imperfect inspection on profit by simulation. Then, this article provides a guideline for the inspection policy which provides the maximum profit.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.290-293
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• 1996

This paper presents an EMQ model which determines an optimal production run length in a deteriorating machine. It is assumed that a machine is subject to a random deterioration from an in-control state to an out-of-control state with an arbitrary distribution and thus producing constant proportion of defective items. An average cost function and an optimal production run length are determined. A mistake in previous model is found and discussed. A mistake in previous model is found and discussed. Numerical experiments are carried out to see the behavior of the proposed model depending on the cost factors as well as machine parameters, and some interesting behaviors are observed.

• 품질경영학회지
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• 제8권2호
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• pp.15-22
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• 1980

This paper deals with the problem of determining a minimum cost sampling inspection plan for a single destructive testing by attribute. The cost for inspection lot is constructed by following three cost factors: (1) cost of inspection, (2) cost of accepted defective, (3) cost of rejected lot Using Hald's Bayesian approach in a single non-destructive testing, procedure's for finding the minimum cost single destructive sampling inspection plan by attribute are given. Assuming the uniform distribution as a prior-distribution and using numerical analysis by computer, a minimum cost single destructive sampling inspection plan by attribute for several lot sizes, unit cost, destructive testing cost, and salvage cost is given.

• 품질경영학회지
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• 제25권1호
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• pp.182-192
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• 1997

The well-known standard normal distribution has been used within the limit of standard variable value of u=3.59. However, the probability values above the limit are not given in the literature. In this study, a probability computation program for standard normal distribution to u=5.99 with the proportional normal distribution a, pp.oximation suggested by Abramowitz and Stegun, Hastings is developed. The new standard normal distribution table developed by the program is presented and will be of help to estimate of probability values for testing and estimation of process mean value, lot acceptable probability, defective percentage of PPM unit of an out-of specification limit, process capability, test power of control charts, probability and statistics.

• 품질경영학회지
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• 제22권4호
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• pp.13-27
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• 1994

This study is concerned with design of EWMA control charts for counted data. Control charts for the fraction defective and the number of defects are designed. Performance analysis is accomplished for validity of the designed EWMA control charts. Average run length(ARL) is adopted as a criterion for comparison. Simulation results show that the designed EWMA control charts have shorter ARL than pn, p and c control charts when the fraction nonconforming or the average defect number are shifted. This means that the designed control charts can detect the out of -control state of the process more fastly than the traditional control charts.

• 품질경영학회지
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• 제23권3호
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• pp.140-155
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• 1995

This paper proposes a quality control method of assembly parts based on parts inspection information. We use the parts inspection information for reduction of defective fraction in assembly and prediction of assembly quality. At first, we build the functional relationship between parts and assembled unit by regression analysis. Secondly, if we use the inspection informations of parts which are estimators of means and variances, we can predict the nonconforming probability of assembled unit and propose the best assembly method. In a case study, we showed the efficency of the proposed method in two part assembly.

• 가족자원경영과 정책
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• 제8권3호
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• pp.33-46
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• 2004

This study examined the effects of consumers' perceptions and expectations about refund on consumers' behavior to refund and its outcome. Major results of this study could be summarized as follows. First, consumers' perceptions and expectations about refund were higher in the case of defective products. However, consumers' behavior to refund were generally passive resulting in the low chance of refund. When there was no defects in product, consumers perceptions and expectations for refund were generally lower resulting in passive and the low chance of refund. Second, when there was defects in product, both consumers' perceptions and expectation tot refund influenced their active behaviors for refund, but not in the successful outcome. In contrast, when there was no defect, those two variables impacted on the behaviors for refund positively In addition, the more active those behaviors requesting for refunds were, the more successful outcome in refund request.

• 경영과학
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• 제16권2호
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• pp.79-92
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• 1999

This paper presents an automated visual inspection/measuring system for the door inner panel manufacturing process. The main objective of this research is to develop inspection applications with a machine vision system related to the determination or quantification of parameters such as dimension, shape, quality of surfaces, number of holes in a panel, and presence or absence of specific features. For quality measurements, we showed a subpixel image processing technology that will improve the consistency of results and level of precision. Also presented is a data analysis method th detect process shifts so that corrective action can be undertaken before more defective units are manufactured.

• 대한안전경영과학회지
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• 제22권3호
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• pp.9-14
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• 2020

A forklift accident occurs in the logisitcs center. there are many kinds of accidents such as a casualty accident or a minor accident, etc. there are many other causes of accident, including poor visibility and habitual operational mistakes The result of the accident is the phenomenon of cutting, falling, scratching of the product. In the case of minor accidents, workers do not report accidents, so the occurrence of accidents is unknown. The customer receives the goods and then notifies them that they are defective product. After the product is returned, we can see that the forklift accident caused the problem of the product The result of the late response affects the image of the enterprise. In this study, we recognized the need for safety education to prevent accidents and found out which of the education items could raise awareness of safety. As result of the study, disinfection and forklift maneuverability regarding speed were mentioned as the most important items in education.