• Journal of Korean Society for Quality Management
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• v.50 no.2
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• pp.265-286
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• 2022

Purpose: The time and cost of a project activity exists in a selected mode and there is a quality level for the selected mode, and the time and cost of the current activity is determined by the quality level of the preceding activity. When an activity is a predecessor activity of an activity, it is characterized as a trade-off problem in which the time and cost of the activity are determined according to the quality level of the activity. Methods: A neighbor search heuristic algorithm obtains a solution by (1) randomly determining the mode, quality level, and assignment order for each activity. (2) get a solution by improving the solution by changing the possible modes and quality levels; (3) to find a solution by improving the solution from the point where it is feasible to advance the start time. Here, Case[1] is a method to find the optimal solution value after repeating (1). Case [2] is a method for finding a solution including (1) and (2). Case [3] refers to a method for finding solutions including (1), (2), and (3). Results: It can be seen that the value of the objective function presented by the algorithm changes depending on how the model of the heuristic algorithm is designed and applied. In other words, it suggests the importance of algorithm design and proves the importance of the quality problem of activities in the project schedule. Conclusion: A study significance of the optimization algorithm and the heuristic algorithm was applied to the effect of the quality of the preceding activity on the duration and cost of itself and the succeeding activity, which was not addressed in the project schedule problem.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.3
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• pp.145-153
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• 2018

Taguchi regarded the concept of quality as 'total loss to society due to fluctuations in quality characteristics from the time of supplied to the customer.' The loss function is a representative tool that can quantitatively convert the loss that occurs due to the deviation of the quality characteristic value from the target value. This has been utilized in various studies with the advantage that it can change the social loss caused by fluctuation of quality characteristics to economic cost. The loss function has also been used extensively in the study of producer specification limits. However, in previous studies, only the second order loss function of Taguchi is used. Therefore, various types of losses that can occur in the process can't be considered. In this study, we divide the types of losses that can occur in the process considering the first and second loss functions and the Spiring's reflected normal loss function, and perform total inspection before delivering the customer to determine the optimal producer specification limit that minimizes the total cost. Also, we will divide the quality policy for the products beyond the specification limits into two. In addition, we will show the illustration of expected loss cost change of each model according to the change of major condition such as customer specifications and maximum loss cost.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.33
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• pp.39-43
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• 1995

The purpose of this article was to understand the individual proportion of quality costs which have been expended by manufacturing industries in Seoul and Kyunggido district. The collected data on 72 firms could be use for an empirical analysis and the ratio test was implementented with the questionnaires. The finding were as following : by conparison with the proportion of quality cost in typical manufacturing industrial of U.S., We concluded that total quality cost was occupied with a small portion of sale. Also as compared with the individual item of quality cost, it was noted that the proportion of prevention cost had increased in a relatively large company.

• Journal of Korea Society of Digital Industry and Information Management
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• v.7 no.3
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• pp.137-150
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• 2011

Long-term customer retention strategies with switching cost is very important for gaining a competitive advantage in on-line shopping mall environment. The purpose of this study is to investigate the affecting factors of switching cost in terms of on-line shopping mall's quality and the effects of it on customers' behavior moderating commitment. According to the result, information quality and customized information were found to be significantly related to social switching cost, and also royalty program and product differentiation were found to be significantly related to lost benefit cost and procedural cost respectively. When it comes to the relationship between switching cost and commitment, results shows that social switching cost is not significantly related to affective commitment. Lost benefit cost and procedural cost, however, were found to be significantly related to affective commitment and calculative commitment respectively. Finally, affective commitment was found to bolster repurchase intention and control negative WOM, and calculative commitment was found to bolster both repurchase intention and negative WOM.

• Journal of Nutrition and Health
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• v.39 no.8
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• pp.832-840
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• 2006

This study was performed to investigate the relationship between diet quality and food cost and identify the effects of food cost on healthy diet among Korean adult. Among the subjects of 2001 National Health and Nutrition Survey 1,641 men and 1,765 women aged from 30 to 49 years were selected and their information of dietary intakes, socio-demo-graphic information, and anthropometric data were analyzed. For the analysis, subjects were classified to quartile based on their daily food cost. Food guidelines provided by Korean Nutrition Society was regarded as a model of healthy diet. Subjects in the lowest quartile of food cost consumed inadequate amount of food from all food categories of the guidelines. Many subjects in the highest quartile not only satisfied the recommended amount of the Food Guide but also seemed to overeat high energy density foods. Even in the highest quartile, about 90% of subjects did not satisfied recommended amount of dairy products. According to the calculated cost of healthy diet, the average cost did not seem to be more expensive than the current mean food cost of the subjects, and most cost-sensitive food intake was observed in the meat fish beans eggs category. The implications of study results were: 1) all the high cost diets did not indicate the high quality of diet, 2) most practical matter of healthy diet in low income group seemed whether they could afford the expense of meat and fish, 3) nutrition education was required to most subjects for healthy diet.

• Journal of Korean Society for Quality Management
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• v.8 no.2
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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.

• The Journal of Information Systems
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• v.20 no.3
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• pp.161-186
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• 2011

To date, SCM research has mainly focused on the effects of controlled variables on SCM success and emphasized adoption strategies and critical success factors. Consequently, the effects of more uncontrolled variables such as partnership between SCM partners have been largely ignored. The purpose of this study, therefore, is to examine the effects of both controlled variables and uncontrolled variables on SCM performance through affecting RTE characteristics. The six factors examined in this study include Quality of information, partnership quality, Forecasting, Agility, Visibility, and SCM performance. In this study, SCM Performance was divided into three categories: Quality Performance, Cost Performance, Delivery Performance. All factors were examined from the perspective of part suppliers. The results of this study can be summarized as follows. First, SCM information quality positively affected SCM partnership quality, Forecasting, Agility, Visibility. Second, SCM partnership quality positively affected Forecasting, Agility. But, SCM partnership quality showed no significant effect on Visibility. Third, Forecasting had a significant impact on SCM performance. According to the detailed result of measuring SCM performance with Quality Performance, Cost Performance, Delivery Performance, although Forecasting affects Cost Performance, Delivery Performance directly, it does not affect Quality Performance directly. Fourth, Agility also had a significant impact on SCM performance. According to the detailed result of measuring SCM performance, Agility has significant impact on Quality Performance, Cost Performance, Delivery Performance. Fifth, Visibility, as expected, had a significant impact on SCM performance. According to the detailed result of measuring SCM performance, Visibility has significant impact on Quality Performance, Cost Performance, Delivery Performance.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.35
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• pp.17-24
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• 1995

The classification of quality costs by item is essencial to sum up the entire quality cost but the reality of classifying the quality cost by the firm is facing with difficulty in terms of grouping the concerned items. Meanwhile, the classification of items and calculating method of quality costs should be prepared in adcance with a certain standards and or regulations to figure out the accurate quality costs successfuly. This case study provides the contents of quality costs calulated by item and the method of calculation in detail which is applicable to automobile component industry md, also introduce how to set up the computing system of quality costs.

• Journal of Korean Society for Quality Management
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• v.21 no.1
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• pp.108-120
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• 1993

In this article an economic life test sampling plan is considered for repairable products when the products in each lot have the same interfailure time distribution, but the mean time between failure (MTBF) of a lot varies from lot to lot according to a known prior distribution. A cost model is constructed which consists of test cost, accept cost, and reject cost. Determination of the optimal plan which minimizes the expected average cost per lot is discussed. Numerical examples are presented to illustrate the use of the proposed sampling plans and sensitivity analyses for parameters of the prior distribution are performed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.218-228
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• 2020

The material industry is an important infrastructure industry that uses process technology in order to produce parts applied to the final product and determine the quality of the finished product. However, the market environment, which has been recognized as a 3D industry, has deteriorated recently and lost competitiveness compared to other material industry countries. This study analyzed the characteristics of forging companies and The study found that three characteristics of the forging industry, facility-oriented, order-based, and field-centered, and internal failure cost and external failure costs were set as the range of quality cost. A total of eight quality tasks were selected by applying the quality cost management system and continuous quality improvement process developed for large-scale A forging company, and improvement activity proved its effectiveness reducing quality costs by 63.3% compared to the previous year. The research helps forging companies establish a quality management strategy by systematically managing and analyzing quality costs.