• 품질경영학회지
• /
• 제32권4호
• /
• pp.242-251
• /
• 2004

Several statistical methods are introduced 1=o analyze the accelerated failure time data. Most frequently used method is the log-linear approach with parametric assumption. Since the accelerated failure time experiments are exposed to many environmental restrictions, parametric log-linear relationship might not be working properly to analyze the resulting data. The models proposed by Buckley and James(1979) and Stute(1993) could be useful in the situation where parametric log-linear method could not be applicable. Those methods are introduced in accelerated experimental situation under the thermal acceleration and discussed through an illustrated example.

• 품질경영학회지
• /
• 제22권2호
• /
• pp.33-40
• /
• 1994

Most software reliability models and other methods attempt to estimate some measures based on its fault history. There are several phases of the software life cycle including testing phase. We can propose it's stopping rule to decide when to stop the testing and pass it on to the next phase by considering the detailed structure of software and calculating the failure rate when each fault was detected. Downs (1985) proposed a method which was developed for estimating the failure rate applicable only to two-level profiles. In this paper, I extended to profiles involving more levels.

• 품질경영학회지
• /
• 제30권4호
• /
• pp.78-85
• /
• 2002

The problem of trend change in the mean residual life is great interest in the reliability and survival analysis. In this paper, a new test statistic for testing whether or not the mean residual life changes its trend is developed. It is assumed that neither the change point nor the proportion at which the trend change occurs is known. The asymptotic null distribution of test statistic is established and asymptotic critical values of the asymptotic null distribution is obtained. Monte Carlo simulation is used to compare the proposed test with previously known tests.

• Journal of Information Processing Systems
• /
• 제14권3호
• /
• pp.607-620
• /
• 2018

The problem surrounding methods of implementing the software testing process has come under the spotlight in recent times. However, as compliance with the software testing process does not necessarily bring with it immediate economic benefits, IT companies need to pursue more aggressive efforts to improve the process, and the software industry needs to makes every effort to improve the software testing process by evaluating the Test Maturity Model integration (TMMi). Furthermore, as the software test process is only at the initial level, high-quality software cannot be guaranteed. This paper applies TMMi model to Automobile control software testing process, including test policy and strategy, test planning, test monitoring and control, test design and execution, and test environment goal. The results suggest improvement of the automobile control software testing process based on Test maturity model. As a result, this study suggest IT organization's test process improve method.

• Tribology and Lubricants
• /
• 제36권3호
• /
• pp.161-167
• /
• 2020

Petroleum is the most used energy source in Korea with a usage rate of 39.5% among the available 1st energy source. The price of liquid petroleum products in Korea includes a lot of tax such as transportation·environment·energy tax. Thus, illegal production and distribution of liquid petroleum is widespread because of its huge price difference, including its tax-free nature, from that of the normal product. Generally, illegal petroleum product is produced by illegally mixing liquid petroleum with other similar petroleum alternatives. In such case, it is easy to distinguish whether the product is illegal by analyzing its physical properties and typical components. However, if one the components of original petroleum product is added to illegal petroleum, distinguishing between the two petroleum products will be difficult. In this research, we inspect illegally produced gasoline, which is mixed with methyl tertiary butyl ether (MTBE) as an octane booster. This illegal gasoline shows a high octane number and oxygen content. Further, we analyze the different types of green dyes used in illegal gasoline through high performance liquid chromatography (HPLC). We conduct component analyses on the simulated sample obtained from premium gasoline and MTBE. Finally, the illegal gasoline is defined as premium gasoline with 10% MTBE. The findings of this study suggest that illegal petroleum can be identified through an analytic method of components and simulated samples.

• 방송공학회논문지
• /
• 제2권1호
• /
• pp.24-35
• /
• 1997

디지털 위성 방송의 비디오 화질 의 주관적 평가 시험을 MPEG-2 MP@ML 표준에 기초하여 설계된 하드웨어 부호화기/복호화기 기본 화질 평가와 위성 전송 에러 화질 및 전송 시스템 성능에 따른 화질 열화에 대한 시험을 위성 시뮬레이터(Satellite Simulator)를 사용해 실시간에서 수행하였다. 평가 방법으로는 CCIR 500-5의 2중 자극 열화 척도법과 2중 자극 연속 화질 척도법을 사용하였다. 또한 디지털 위성 방송 시스템의 화질을 전체 시스템 즉 MPEG-2코덱, 다중화 장치, 채널 코덱, 변복조기, 안테나 등을 연계시켜 여러 비트율과 비트 오류율에서 평가 시험을 수행함으로써 시스템 전반적인 성능을 평가하고 위성 전송로와 수신 시스템을 연계한 전송로 환경을 고려한 보다 통합적인 화질 평가 시험을 수행하였다. 특히 전송로 오류 화질 평가에 있어서 주어진 5가지의 BER에 대하여 전송 에러 화질은 평균적으로 5단계 카테고리에서 3.9이상을 유지함을 알 수 있었다. 필름 모드와 같은 낮은 비트율(특히 2Mbps)에서 코덱 시스템의 부호화 화질의 성능은 영상 소스의 통계적 성질에 따라 크게 좌우됨을 알 수 있었고 평균적으로 절대 평가 기준에서 2.7정도를 기록하였다.

• 분석과학
• /
• 제25권2호
• /
• pp.102-113
• /
• 2012

현행 환경오염공정시험기준 중 먹는 물 수질공정시험기준과 실내공기질 공정시험기준에 대해 국제규격에 부합화된 KS ISO규격과의 일원화에 관해 연구하였다. KS규격 23,000여종을 대상으로 먹는 물 및 실내공기질관련 KS 규격을 조사하였다. 환경분야관련 KS규격은 KS I로 분류되며, 총 653종으로 조사되었으며, 이중 국제규격에 부합화된 KS I 규격은 583종으로 조사되었다. 먹는 물 수질공정 시험기준은 총 100개 기준을 대상으로 ISO/TC 147 "Water Quality" 관련 KS 규격 총 232종을 비교 검토하였으며, 실내공기질 공정시험기준은 "ISO/TC 146 "Air Quality" 관련 KS 규격 총 95종 규격을 비교 검토하였다. 문헌검토와 비교시험을 통해 먹는 물 및 실내공기질 공정시험기준과 일원화 가능한 국제규격에 부합화된 KS규격 연구결과 먹는물수질공정시험 100개 기준 중 사전일원화 완료 23개 기준, 일원화 가능 29개 기준, 일원화 불가 12개 기준, 대응 규격 없는 기준이 36개로 평가되었으며, 실내공기질 공정시험기준 17개 기준 중 사전일원화 완료 1개 기준, 일원화 가능 3개 기준, 일원화 불가 3개 기준, 대응규격 없는 기준이 10개 기준으로 평가되었다.

• International Journal of Contents
• /
• 제13권1호
• /
• pp.38-44
• /
• 2017

Increased use of software and complexity of software functions, as well as shortened software quality evaluation periods, have increased the importance and necessity for automation of software testing. Automating software testing by using machine learning not only minimizes errors in manual testing, but also allows a speedier evaluation. Research on machine learning in automated software testing has so far focused on solving special problems with algorithms, leading to difficulties for the software developers and testers, in applying machine learning to software testing automation. This paper, proposes a new machine learning framework for software testing automation through related studies. To maximize the performance of software testing, we analyzed and categorized the machine learning algorithms applicable to each software test phase, including the diverse data that can be used in the algorithms. We believe that our framework allows software developers or testers to choose a machine learning algorithm suitable for their purpose.

• 산경연구논집
• /
• 제10권9호
• /
• pp.37-43
• /
• 2019

이 논문은 즉석섭취식품으로 분류되는 김밥용 김에 관한 자가품질검사의 개선안을 제시하였다. 김밥용 김에 적용하는 검사항목 중 장염비브리오균은 3가지 측면에서 적합하지 않다. 첫째, 선행연구 가운데 김밥용 김에서 장염비브리오균을 발견한 사례가 전무하다. 둘째, 전수조사 성격의 자가품질검사 부정합 내역(2015~16년)에 김밥용 김이 적시된 적이 없다. 셋째, 국제기준인 CODEX 규정은 해조류에 장염비브리오균 검사 의무를 부여하지 않는다. 끝으로, 수출용 김과 조미김 및 기타 수산물가공품 유형에 해당 검사가 면제된다. 이에 따라 김밥용 김에 대한 장염비브리오균 검사의무의 면제는 타당하며 그에 따른 경제적 이득은, 특히 영세업체에 클 것으로 추정된다. 2018년 3월 중 총 75곳의 자가품질 검사기관에 대한 전화 및 서류조사 결과 업체당 수수료 절약 규모는 업체당 연평균 13만 원에 이를 것으로 산출하였다. 또한, 검사의 투명성과 효율을 제고하기 위해서는 검사기관 간 수수료의 조화가 필요할 것으로 판명되었다.

• 한국컴퓨터정보학회논문지
• /
• 제23권2호
• /
• pp.9-16
• /
• 2018

Recently, as various IP set-top boxes based on Android OS have been widely used in general households and public facilities, complaints about services and set-top boxes have continued to increase as much as other smart devices. In order to reduce this problem, the manufacturer performs the testing work before the product is commercialized. However, the testing can reduce potential defects in the product, but it can not prove that the product is free of defects. Therefore, the quality of the product can vary depending on how effective testing techniques are introduced. In this paper, we propose a new exploratory testing method that minimizes test case creation time and makes it easier to plan and execute test while simultaneously learning how to run the product under test. Using the first proposed method, the test time is reduced by about 16.7 hours and the defect detection rate is 25.4% higher than the formal specification-based testing method. Informally, the test time was shortened by about 4.7 hours and the defect detection rate was 13% higher than the informal experience-based testing method.