• 한국경영과학회:학술대회논문집
• /
• 대한산업공학회/한국경영과학회 1994년도 춘계공동학술대회논문집; 창원대학교; 08월 09일 Apr. 1994
• /
• pp.78-78
• /
• 1994

• 대한산업공학회지
• /
• 제22권1호
• /
• pp.51-63
• /
• 1996

In this paper, we develop two replacement-type reliability acceptance sampling plans(RASPs) for the gamma lifetime distribution assuming that the shape parameter is known. The two plans are respectively based upon failure-free period and hybrid life tests. We then compare the plans in terms of expected test time to reach a decision, power, etc. Computational results indicate among others that the failure-free period RASP has a shorter expected completion time than the corresponding hybrid RASP when the true scale parameter is 'large'. Finally, sensitivity analyses reveal that the effects of the uncertainties involved in the assumed shape parameter on the producer and the consumer risks are in favorable directions for both parties for both types of plans.

• 한국시뮬레이션학회논문지
• /
• 제9권2호
• /
• pp.75-87
• /
• 2000

In this paper, nonstationary multiple sampling plans are discussed which are difficult to solve by analytical method when there exists dependency between the sample data. The initial solution is found by the sequential sampling plan using the sequential probability ration test. The number of acceptance and rejection in each step of the multiple sampling plan are found by grouping the sequential sampling plan's solution initially. The optimal multiple sampling plans are found by simulation. Four search methods are developed U and the optimum sampling plans satisfying the Type I and Type ll error probabilities. The performance of the sampling plans is measured and their algorithms are also shown. To consider the nonstationary property of the dependent sampling plan, simulation method is used for finding the lot rejection and acceptance probability function. As a numerical example Markov chain model is inspected. Effects of the dependency factor and search methods are compared to analyze the sampling results by changing their parameters.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2008년도 춘계학술대회 논문집
• /
• pp.997-998
• /
• 2008

• 한국IT서비스학회지
• /
• 제13권4호
• /
• pp.309-324
• /
• 2014

This case study focuses on the preparing a guide for the plan to the companies that want to build a business document system for the centralized services under the cloud computing. Total 3 Operating companies with regard to cloud computing issues are introduced for this purpose. Analyzing the usage and development direction of the selected companies were performed to set up plans. Through this in-depth needs of the user's point of view for the management of business documents, The necessary improvements in the process of collaboration and document sharing were derived. Business documents centralized service plans were proposed based on cloud computing models. Practical experiences of the companies were helpful to present the details of the operational strategy and operational plans. Especially with minimal staff input and verification process, Sample method for the automatic generating of the new document file name is introduced. A test bed before operating the enterprise-wide system were presented with information that is to be considered when building systems.

• 대한산업공학회지
• /
• 제17권1호
• /
• pp.95-108
• /
• 1991

For the case where the lifetime at a constant stress level has exponential distribution, optimal accelerated life test plans are developed under the assumptions of intermittent inspection and Type I censoring. In a optimal plan, the low and high stress levels, the proportion of test units allocated and the inspection times at each stress are determined such that the asymptotic variance of the maximum likelihood estimator of logarithmic transformed mean at the use condition is minimized. In addition to the optimal plan in which numerical technique to solve the set of nonlinear equations must be employed to determine inspection times at each stress level, we also propose another plans which employ equally-spaced or equal probability inspection schemes at two overstress levels of corresponding optimal one. For both optimal and proposed plans, computational results indicate that the asymptotic variance of the estimated mean at the use stress is insensitive to number of inspections at overstress levels for the range of parameter values considered.

• 한국환경교육학회지:환경교육
• /
• 제20권3호
• /
• pp.1-17
• /
• 2007

The purpose of this study was to establish objectives for ninth grade studies of heredity and evolution in middle school in an attempt to foster students' consciousness of bioethics, and it's additionally intended to develop and apply lesson plans handling different points at issue and to determine the effects of the lesson plans on the bioethics of middle school students. The subjects in this study were 152 ninth graders in a middle school, whose science scores were similar. An experimental group and a control group were made up of 76 students respectively, and a pretest was conducted with test paper developed by this researcher to assess their awareness of bioethics. The experimental group took lessons by using the teaching plans prepared in this study, and the control group received typical education according to the curriculum. And then a posttest was implemented with test paper developed in this study to compare the two groups. In addition their science grades were compared as well. The findings of the study were as follows: First, seven learning objectives were selected from three units related to bioethics in the third-year 8th category of heredity and evolution of middle school. Second, in order to attain the selected learning objectives, four session lesson plans were prepared. Third, the experimental group that studied using by the lesson plans made better progress in bioethics awareness and the gap between the two was statistically significant(t=6.61, p<.001). The former were ahead of the latter in consciousness about species equity(t=7.71, p<.001), the dignity of life (t=3.78, p<.001), human rights(t=2.99, p<.01) and equity among generations(t=2.66, p<.01), but not in awareness of the diversity of species. Fourth, there was no significant gap in science scores between the students studied according to the curriculum and those who received instructions by using the lesson plans developed in the study.

• 품질경영학회지
• /
• 제43권2호
• /
• pp.169-184
• /
• 2015

Purpose: This paper is concerned with optimally designing accelerated degradation test (ADT) plans based on a gamma process for the degradation model. Methods: By minimizing the asymptotic variance of the MLE of the q-th quantile of the lifetime distribution at the use condition, the test stress levels and the proportion of test units allocated to each stress level are optimally determined. Results: The optimal plans of ADT are developed for various combination of parameters. In addition, a method for determining the sample size is developed, and sensitivity analysis procedures are illustrated with an example. Conclusion: It is important to optimally design ADT based on a gamma process under the condition that a degradation process should be always nonnegative and strictly increasing over time.

• 대한산업공학회지
• /
• 제22권3호
• /
• pp.459-471
• /
• 1996

This paper considers ramp tests for exponential lifetime distribution when there are limitations on test stress and test time. The inverse power law and a cumulative exposure model are assumed. Maximum likelihood (ML) estimators of model parameters and their asymptotic covariance matrix are obtained. The optimum ramp test plans are also found which minimize the asymptotic variance of the ML estimator of the log mean life at design constant stress. For selected values of the design parameters, tables useful for finding optimal test plans are given. The effect of the pre-estimates of design parameters is studied.

• Journal of Information Processing Systems
• /
• 제1권1호
• /
• pp.75-78
• /
• 2005

Although many tests for stabilization of the software have been done, vulnerability test for a system run by combination of the software of various products has not been conducted enough. This has led to increased threats and vulnerability of system. Especially, web-based software system, which is public, has inherent possibility of exposure to attacks and is likely to be seriously damaged by an accident. Consequently, comprehensive and systematic test plans and techniques are required. Moreover, it is necessary to establish a procedure for managing and handling the results of vulnerability test. This paper proposes vulnerability test plans and designs for implementing automated tools, both of which can be complied with on web-based software systems.