• Communications for Statistical Applications and Methods
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• v.12 no.1
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• pp.11-18
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• 2005

Assume that the life times of the units under test follow the Rayleigh distribution and the test is terminated at a pre assigned time. Acceptance sampling plans are developed for this situation. The minimum sample size necessary to ensure the specified average life are obtained and the operating characteristic values of the sampling plans and producer's risk are given. An example is given to illustrate the methodology.

• Industrial Engineering and Management Systems
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• v.14 no.2
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• pp.183-195
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• 2015

In this paper, we propose a two-stage group acceptance sampling plan for generalized inverted exponential distribution under truncated life test. Median life is considered as a quality parameter. Design parameters are obtained to ensure that true median life is longer than a given specified life at certain level of consumer's risk and producer's risk. We also explore situations under which design parameters based on median lifetime can be used for other percentile points. Tables and specific examples are reported to explain the proposed plans. Finally a real data set is analyzed to implement the plans in practical situations and some suggestions are given.

• Journal of Korean Society of Rural Planning
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• v.26 no.3
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• pp.25-38
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• 2020

The purpose of this study is constructing a regional-level crop acreage choice model incorporating the impacts of producer risk aversion, and applying the constructed model to the Korean policy that promotes rice paddy conversion into non-rice crop fields. The study adopts the approach of Paris (2018) which estimates the absolute risk aversion coefficient inside of a positive mathematical programming model. A panel data set of 143 cities/counties is used for the empirical study where agricultural land in each region is allocated to 8 crops. Our estimated absolute risk aversion coefficients are smaller than those of Paris (2018), but are a little bit larger than those of the existing Korea studies based on survey or econometric methods. We found that there are close relationships among the estimated risk aversion, regional characteristics, and farming patterns. We also found that incorporating the estimated risk attitudes results in substantial differences in the impacts of the rice paddy conversion policy.

• International Journal of Human Ecology
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• v.6 no.2
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• pp.63-72
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• 2005

This paper considered the impact of changing the product liability rule from consumer to producer liability on product safety under asymmetric information. In particular, it has been attempted to remove several constraints on antecedent studies. The main results of the study are as follows: under the misperception of the risk on a product, consumers may underestimate the probability of product failure. In this case, the accident rate can be lowered under the producer's liability rule. However, even under the asymmetric information, a consumer's estimation on the probability may be converged with the expected risk level, which could be called the 'rational expectation.' In this situation the probability of product failure can be lowered under the strict liability with contributory negligence. Additionally, it is possible to reduce the probability of product failure when a legal rule that imposes liability on cheapest cost avoider is admitted.

• Industrial Engineering and Management Systems
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• v.11 no.4
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• pp.390-396
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• 2012

The present paper extends the idea of tightened-normal-tightened sampling scheme to group acceptance sampling plans under the time truncated life tests. We consider three famous distributions that are widely used in the area of reliability such as the generalized exponential distribution, the Weibull distribution, and the Birnbaum-Saunders distribution in the proposed sampling plan. The plan parameters are determined such that the producer's risk and the consumer's risk are satisfied at the specified median life. Extensive tables showing plan parameters are provided at various values of the experiment time and the consumer's risk for each of three distributions for the practical use. Some examples are given to illustrate the procedure of the proposed plan.

• Journal of the Korea Safety Management & Science
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• v.6 no.2
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• pp.91-101
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• 2004

Consumers require various quality characteristics including safety. The reduction of risk concerned on product safety becomes an urgent issue in leading companies. The strategy for customer satisfaction by choosing attractive quality characteristic is not enough for risk reduction in view of producer. This paper presents a method for choosing quality characteristics and risk characteristics by integrating QFD based on quality requirements and AHP based on safety requirements, also shows its application for complex equipment.

• Proceedings of the Safety Management and Science Conference
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• 2004.05a
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• pp.137-144
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• 2004

Consumers require various quality characteristics including safety. The reduction of risk concerned on product safety becomes urgent issue in leading companies. The strategy for customer satisfaction by choosing attractive quality characteristic is not enough for risk reduction in view of producer. This paper presents a method for choosing quality characteristics and risk characteristics by integrating QFD based on quality requirements and AHP based on safety requirements, also shows its application for complex equipment.

• Communications for Statistical Applications and Methods
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• v.18 no.4
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• pp.403-411
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• 2011

This paper deals with a group acceptance sampling plan for time truncated tests which are based on the total number of failures from the whole group assuming that the life time of an item follows the Dagum (inverse Burr) distribution. This study is developed when a multiple number of items as a group can be tested simultaneously in a tester. The minimum number of groups required for a given group size and acceptance number is determined such that the producer and consumer risks are satisfied simultaneously at the specified quality level, while the termination time and the number of testers are specified. Comparisons are made between the proposed plan and the existing plan on the basis of size of the groups. Two real examples are provided.

• International Journal of Reliability and Applications
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• v.15 no.2
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• pp.77-84
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• 2014

In this paper, a optimal designing methodology is proposed to determine the parameters for skip-lot sampling plan of type SkSP-2 plan with double sampling plan as reference plan, when the lifetime of the product follows generalized exponential distribution. The two points on the operating characteristic curve approach are used to find the optimal parameters for the proposed plan. The plan parameters are determined so as to minimize the average sample number subject to satisfying simultaneously both producer and consumer risks at the acceptable and limiting quality levels respectively.

• Communications for Statistical Applications and Methods
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• v.17 no.1
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• pp.89-98
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• 2010

In this paper, a two-stage group sampling plan based on the time truncated life test is proposed for the Weibull distribution. The design parameters such as the number of groups and the acceptance number in each stage are determined by satisfying the producer's and consumer's risks simultaneously when the group size and the test duration are specified. The acceptable reliability level is expressed by the ratio of the true mean life to the specified life. It was demonstrated from the comparison with single-stage group sampling plans that the proposed plan can reduce the average sample number or improve the operating characteristics.