• The Korean Journal of Applied Statistics
• /
• v.6 no.2
• /
• pp.277-287
• /
• 1993

This paper is a generalization of single- and two-level skip-lot sampling plans to n-level, which can considerably reduce inspection cost when the level of submitted quality is high. In every skipping inspection of the generalized sampling plan, not only skipping parameters but also inspection fractions can be freely choosed. The general formula of the operating characteristic function for the n-level skip-lot sampling plan is derived. Also the operating characteristic curves of a reference plan, two-level and three-level skip-lot sampling plans are compared.

• Industry Promotion Research
• /
• v.8 no.1
• /
• pp.111-117
• /
• 2023

Sampling inspection methods for quality control have been proposed a lot in the industry. However, the sampling inspection method for reliability, which is a quality over time, has been relatively less presented, and there are not many literatures that are clearly summarized. Therefore, this paper focuses on the reliability conformity test to verify that the reliability evaluation scale value of the target is satisfied during the reliability test. To this end, first, we look at the conditions that both consumers and producers can satisfy in terms of the OC curve and find out what sampling methods satisfy the desired level of producer risk and consumer risk. Next, two methods of the reliability sampling methods such as attribute and variable reliability sampling methods are examined. Specifically, the attribute reliability sampling method is a form of sampling plan where n samples are tested for a certain period of T hours and the lot is accepted if the number of failures is less than or equal to a certain number c. On the other hand, the variable reliability sampling method is a form of sampling plan where the lot is accepted if the reliability evaluation scale such as MTBF satisfies a certain standard. Both sampling plans may also use inspection tables.

• The Korean Journal of Applied Statistics
• /
• v.8 no.2
• /
• pp.55-64
• /
• 1995

Three-level Skip-lot sampling plan split by two stages (Split2-SkSP0 is proposed by modifying multi-level skip-lot sampling plan proposed by Choi(1993), which has normal and terrace inspections on the first and the second stages, respectively. The plan is designed to work more higher level inspections when the quality of the submitted products are good, otherwise, return to the normal or the terrace inspection as fast as possible. Also, the formula of the operating characteristic function for the split skip-lot sampling plan is derived using the Markov chain approach. Also, operating characteristic properties of the proposed plans are studied and graphically compared with those of the multi-level skip-lot sampling plans.

• Proceedings of the Safety Management and Science Conference
• /
• 2006.11a
• /
• pp.255-267
• /
• 2006

제품을 로트(lot)단위로 구분하고 로트에서 취한 샘플을 검사하여 얻은 품질 특성의 값을 이용해서 로트의 합격여부를 판정하는 것을 샘플링검사(sampling inspection)라 하고, 검사하는 품질특성이 제품의 수명 특성치인 경우에 이를 신뢰성 샘플링 검사(reliability sampling inspection)라 한다. 그 중 벌크재료에 대한 샘플링 검사방식을 알아 보도록한다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2002.11a
• /
• pp.437-440
• /
• 2002

3차원 게임, 컴퓨터 시뮬레이션 등과 같은 대화적 가상환경의 사실성을 높이기 위해 충돌탐지는 절대 필요한 요소가 된다. 하지만 기존의 바운딩 볼륨 기반 기법들은 볼륨 계산의 복잡성 때문에 실시간 어플리케이션에서 정교한 검사를 수행하는데 어려움이 있었다. 본 논문에서는 바운딩 구와 꼭지점 샘플링을 이용한 정교하고도 효과적인 충돌탐지 방법을 제안한다. 한편, 제안된 기법에서는, 반드시 필요한 부분에서만 꼭지점을 이용한 충돌검사를 시행해서 충돌검사의 효율성을 높였고, 이를 위한 샘플링 툴을 제공하였다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.10
• /
• pp.531-538
• /
• 2017

In the case of hydraulic pressure type fuse, we accept or reject certain product lots by considering the number of defective products in the operating pressure test. Generally, this procedure, known as 'The inspection by attributes', has been most commonly used in the field of quality assurance of products. However, the method of inspection by attributes suffers because it tests more samples than inspection by variables. Even though the quality of the products has remained stable in the process condition, the same number of samples is required for every lot, which wastes time and money. This paper suggests that the lot acceptance procedure is changed from inspection by attributes to inspection by variables. We can calculate the statistical tolerance percent of defectives and compare this to the Acceptable Quality Level (AQL) in order to save money and time. It is also easier to monitor and control the quality of products by using the process capability index and x-bar charts. In conclusion, the procedure delivers mutual benefit to both the customer and the producer by securing high quality products and reference data.

• Journal of Korean Institute of Industrial Engineers
• /
• v.6 no.2
• /
• pp.37-47
• /
• 1980

A system of conditional sampling plans composed of three stages is developed. In the first stage, the decision to accept or reject the lot is based on the information obtained from the current lot. When a decision is not made in the first stage, a second stage is introduced and the information from the immediately preceding lot as well as the information from the current lot is used for the decision. When a decision is not made in the first stage, a second stage is introduced and the information from the immediately preceding lot as well as the information from the current lot is used for the decision. When a decision is not made in the second stage either, the decision is deferred until the information from the immediately following lot is obtained. Existing tables for constructing double sampling plans with $_2$=$2n_1$ can be used to find the parameters of these plans. These sampling plans can bring sizable savings in the amount of inspection when the process is relatively stable. The response delay to the change in process quality and the deferred events may be considered as shortcomings of these plans. However, these are not serious in practical applications, and the reduction in sample size may more than offset these shortcomings.

• The Korean Journal of Applied Statistics
• /
• v.10 no.2
• /
• pp.375-384
• /
• 1997

In this paper, chain-shaped multi-level skip-lot sampling plan is designed, which is a normal inspection plan between Choi(1993)'s tightened inspection plan and Choi(1995)'s reduced inspection plan. In every skipping inspection of the proposed plan, when designed numbers of consecutively inspected lots are accepted, switch to the next skipping inspection, and when a lot is rejected, switch to the skipping inspection of two-level lower. Also, the formulae of the operating chareacteristic function, average sampling number and average outgoing quality for the proposed skip-lot sampling plan are derived using the morkov chain approach and their properties are studied and graphically compared with those of the other multi-level skip-lot sampling plans.

• Journal of Korean Society for Quality Management
• /
• v.5 no.1
• /
• pp.11-15
• /
• 1977

• Journal of Korean Society for Quality Management
• /
• v.5 no.1
• /
• pp.20-22
• /
• 1977