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

• Journal of Korean Institute of Industrial Engineers
• /
• v.24 no.2
• /
• pp.279-285
• /
• 1998

A quality inspection procedure interchangeably using the performance and screening variables is proposed. At the start of the inspection, the performance variable is measured for all items. As soon as i consecutive items are found to be free of defects, the screening variable is measured instead of the performance variable. If an item is rejected, the inspection based on the performance variable is resumed. All nonconforming items found in the inspection are either reworked or replaced with conforming items. It is assumed that the performance variable is dichotomous, and the screening variable given the performance variable is normally distributed with known mean and variance. The average outgoing quality (AOQ) expression is derived, and the methods of finding the inspection procedure with a specified average outgoing quality limit (AOQL) are presented.

• Journal of Chest Surgery
• /
• v.17 no.4
• /
• pp.691-697
• /
• 1984

After the real birth of vascular surgery occurred with the introduction of the first practical arterial prosthesis about 50 years ago, a variety of potential vascular graft had been tested and rejected. Polytetrafluoroethylene [Teflon, PTFE] was first used as a vascular prosthesis in 1957. Thereafter this pros-thesis was first used clinically in 1972 and has subsequently been widely applied as a small and medium sized vessel replacement because it is easy to use and readily available. There are numerous reports of good results about Polytetrafluoroethylene graft. We experienced the three cases of arterial bypass graft using polytetrafluoroethylene vascular pros-thesis. First, 21 years old female patient had suffered from Takayasus disease which affected the left subclavian artery and right subclavian-left axillary extra anatomical bypass graft as done. Second, 64 years old male patient had suffered from Leriche syndrome for 12 years and the left axillofemoral and femorofemoral extra anatomical bypass graft was done. Third, 34 years old male patient had suffered from recurrent Buergers disease which affected the left popliteal artery and the isolated popliteal artery segment bypass graft was done. Relatively satisfactory result was obtained in early post-operative period in all three cases.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.35 no.1
• /
• pp.97-109
• /
• 2010

In this paper, we study a joint design problem of sampling inspections and service capacities for multi-products. Products are supplied in batches after rectifying inspections, that is, rejected lots are 100% inspected and defective products are reworked to good ones. When supplied, all defective products are uncovered through total inspection and returned to service. By exploiting the first and second order properties of the objective function, we identify the optimal inspection policies and service capacities for individual products, and develop allocation algorithms to obtain an optimal allocation of the limited total service capacity to products with the small number of computations.

• Journal of Korea Technology Innovation Society
• /
• v.8 no.1
• /
• pp.116-134
• /
• 2005

This paper investigates the relationships between export and firm characteristics, focusing on technology factors. It is based on a longitudinal data covering listed firms in the Korean manufacturing industry. A regression model for the determinant of export/sales ratio including dynamic adjustment process is tested on a cross-section sample of the year 2001. Empirical findings suggest that there is no significant relationship between export/sales ratio and firm's technological level. The hypotheses concerning human capital intensity and physical capital intensity are also rejected. But we found a positive and inversely U-shaped relationship between firm size and export/sales for basic material and capital good industry. As a dynamic aspect, we found that the pattern of export/sales ratio changed unstably over the last decade. Finally, some policy implications are presented.

• Journal of Korean Institute of Industrial Engineers
• /
• v.27 no.4
• /
• pp.366-373
• /
• 2001

Economic component screening procedures for multi-component assembly products supplied with warranty are proposed. It is assumed that the screening variable is continuous and the performance variable is dichotomous. Logistic and normal models are considered; the proportion of conforming items is a logistic function of the screening variable in the logistic model and the screening variable given the performance variable is normally distributed in the normal model. Cost models are constructed which involve three cost components; screening inspection cost for each component, cost due to disposing a rejected component, and warranty cost for an assembly product. Methods of finding the optimal screening procedures are presented and numerical examples are given.

• The Journal of the Korean life insurance medical association
• /
• v.2 no.1
• /
• pp.3-16
• /
• 1985

Necessity of life insurance is stronger for people who feel some anxiety of their health. However, in fact, it is not permitted for them to get a contract, because life insurance stands on the mutual benefit system. Life insurance must be impartial to all applicants. However, it is very reasonable that an applicant, who has high medical impairment like heart infarction or cancer, is rejected, to have a contract by underwriting decision. On the other hand, if his medical impairment is not so severe, we might accept his application by giving some restriction. Numericalratingsystem by hunter-rogers gave us one of solutions to this problem. We can keep impartiality by using more restrictive decision, in order that we demand additional payment to the impairment applicant according to his mortality. We call this system as substandard life insurance. In this system we need detail information about impairments of applicants in order to decide the condition of substandard risks. Therefore, medical examiners are required to have high diagnostic technique.

• Korean Management Science Review
• /
• v.33 no.3
• /
• pp.89-103
• /
• 2016

In this paper, we design sampling inspections and service capacities simultaneously for multi-products. Products are supplied in batches after rectifying inspections, that is, rejected lot is subject to total inspection and defective products are reworked to good ones. When supplied, all defective products are uncovered and returned to service. Particularly, we extend Kim [1] by introducing the fixed costs of providing services and show that the cost function of a product is no longer linear or convex in terms of the level of service provision. We develop a framework for a product to deal with this joint design problem and a dynamic programming algorithm for multi-products which allocates the given number of the total service capacities among products with the considerably smaller computations than the total number of possible allocations.

• Journal of Labour Economics
• /
• v.24 no.3
• /
• pp.1-12
• /
• 2001

Seoul/Kyungki-born workers have higher wages than other regions-born workers. In order to determine whether this difference is due to taste or statistical discrimination, an econometric model is suggested and a test is done with it. According to the test, the hypothesis that the difference is wholly due to taste discrimination is rejected: a part of the difference is due to statistical discrimination. Since statistical discrimination in this paper comes out in the process of a worker's wage being determined according to his productivity, it is no problem for the government to intervene in.

• Journal of Korean Physical Therapy Science
• /
• v.8 no.1
• /
• pp.781-786
• /
• 2001

The purpose of this study is to provide the direction of the policy forwelfare of the home - based service by identifying the problem and improvement of the home - based service. In the fast growing society like korea social welfare policy for the home - based service. The core hypotheses, of this research that home - based services canexpand social support network and improve life satisfaction were aceptedor rejected, In other words, while the home - based services expanded the lold people social support network through the activities of social workers and volunteers, these services considering the findings of the this study, we can conclude that the current home - based services provided by social welfare have an effect upon increasing old peoples social support. But these services have no effect upon improving life satisfaction index.