• 대한기계학회논문집
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• 제11권1호
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• pp.154-159
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• 1987

본 논문에서는 제1보의 결과를 이용하여 절삭속도가 서로 다른 경우의 공구마 멸량을 단일공구에 집적하여 측정할 수 있는지의 가능성 여부를 검토한 후, 절삭속도 를 단계별로 변화시키면서 단일공구로 측정한 각 절삭속도에서의 마멸량(단계절삭자료 라 한다)을 이용하여 측면마멸곡선의 일반모델상수를 결정할 수 있는 계단절삭공식을 유도하였다. 또한 결정된 일반모델상수를 이용하여 Taylor지수와 상수를 구할 수 있 는 수정 Taylor방정식을 제시하고, 공구수명곡선을 구하였다. 그리고 본 연구결과의 신뢰성을 검증하기 위하여 SM45C, P20, 0.3mm/rev., 1.5mm(절삭깊이)의 절삭조건에서 절삭시간과 속도를 변수로 한 기존 시험법의 결과와 비교하였다.

• International Journal of Reliability and Applications
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• 제1권2호
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• pp.115-121
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• 2000

The trend change in aging properties, such as failure rate and mean residual life, of a life distribution is important to engineers and reliability analysts. In this paper we develop a test statistic for testing whether or not the failure rate changes its trend using censored data. The asymptotic normality of the test statistics is established. We discuss the efficiency values of loss due to censoring.

• 소성∙가공
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• 제12권2호
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• pp.88-93
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• 2003

Several alloy bearing steels have been starting to replace for conventional high carbon and high chromium bearing steel since 1980. In this paper the global bearing developing trends were summarized in several important aspects- developments in alloy bearing steels for improved service life, development of inclusion rating method in bearing steel and developments in bearing service life testing.

• International Journal of Reliability and Applications
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• 제13권1호
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• pp.49-56
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• 2012

Using total time on test transform (TTT), a new approach is taken for testing exponentiality versus the unknown age, exponential better than equilibrium life in convex ordering (EBELC). Selected critical values are tabulated for sample size n =2(2)50 and powers of the test are estimated for some commonly used distributions in reliability. Finally real example is presented to illustrate the theoretical results.

• 한국재료학회지
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• 제17권11호
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• pp.580-586
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• 2007

To enhance the reliability of a newly designed reciprocating compressor applied in a domestic compressor, accelerated life tests were developed using new definitions of the sample size and the $B_1$ life index. In $1^{st}$ accelerated life testing, the compressor was locked due to the fracture of the suction reed valve. The failure modes and mechanisms of the suction reed valve in the accelerated tests were found to be similar to that of the failed product in the field. The root cause of the failure was the overlap between the suction reed valve and the valve plate in the suction port. The missing parameters in the design phase were modified by expanding the trespan size, introducing tumbling process, changing the material and thickness for the valve, introducing a ball peening and brushing process for the valve plate. In $2^{nd}$ accelerated life testing, the compressor was locked due to the interference between the crank shaft and thrust washer. The corrective plan was to heat treat the crank shaft. The $B_1$ life of the compressor improved from 1.5 to 12.9 years.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2007년도 학술발표회 논문집
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• pp.385-386
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• 2007

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.184-189
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• 2004

Shot peening process is used as one of the various kinds of techniques to improve the fatigue properties. However, to obtain fatigue properties of metal materials, many efforts and time are needed. Because the fatigue life of shot peened metals increases highly. In this paper, fatigue properties of shot peened Al 7075-T6 are estimated using the fundamental of accelerated life test to reduce the experimental. Experimental results show that the estimated life data almost agree with actual rotary bending fatigue test data within 7% error.

• 한국신뢰성학회:학술대회논문집
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• 한국신뢰성학회 2005년도 학술발표대회 논문집
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• pp.75-82
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• 2005

In this paper, accelerated life testing(ALT) method and procedures for a are developed and applied to assess the reliability of the product. Relay is a device that can open and close the electric circuit electrically and is used for protecting and controlling the load. In this study, an accelerated life test method for predicting the mechanical life of a relay is developed using the relationship between stresses, failure mechanism and life characteristics of products. Using the ALT method, we performed life tests and analyzed the tests results. The proposed method and procedures may de extended and applied to testing similar kinds of products to reduce test times and costs of the tests remarkably.

• 보험의학회지
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• 제12권
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• pp.50-55
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• 1993

1) 생명보험(生命保險)에서의 Screening은 사정조건(査定條件)이며 충분(充分)한 기능(機能)을 갖인 기구(器具)이다. 2) Screening 기술(技術)은 의학적(醫學的)으로 충분(充分)히 명시(明示)되여 있으며 장래(將來)에도 일반적(一般的)인 임상적(臨床的)인 Rule에 따라야 한다. 3) Screening Parameter는 연령(年齡)이나 Risk-Group에 의(依)한 질병(疾病)의 Pattern에 따라야 한다. 4) Screening Parameter에서의 예후(豫後)의 추론(推論)은 임상의학적관찰(臨床醫學的觀察)과 Rule를 모두 고처(考處)하는 한(限)에서는 합법적(合法的)이다. 5) 민감(敏感)한 성격(性格)의 Screening 기술(技術)은 일관성(一貫性)있게 취급(取扱)하기 의(依)해서는 대단(大端)히 특별(特別)한 Rule를 필요(必要)로 한다. 6) HIV-항체시험(抗體試驗)과 같은 Screening-Parameter는 그들의 새로운 시험범위내(試驗範圍內)에서는 계속적(繼續的)인 과학적(科學的) Feedback를 필요(必要)로 한다. 7) 유전의학적시험(遺傳醫學的試驗은 생명보험(生命保險) Screening에서는 아직 사용(使用)하고 있지 않지만 생명보험의학(生命保險醫學)에서는 장래(將來)의 역할(役割)과 가능성(可能性)에 대(對)해서 검토(檢討)해야 될 것이다. 8) 보험업계(保險業界)의 Screening은 가능한(可能限) 역선택(逆選擇)을 배제(排除)하고 보험청약자(保險請約者)나 보험자(保險者)의 쌍방(雙方)에서 평균여명(平均餘命)을 짧게하는 어떠한 결함(缺陷)에도 같은 지식(知識)으로 대비(對備)해야 한다. 9) Screening에서의 Informed Consent, Counselling과 Confidentiality는 현재나 더욱 발전된 장래에서도 알맞게 취급하지 않으면 않된다.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1996년도 제23회 춘계학술대회
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• pp.122-127
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• 1996

In this paper, the effects of the film tinckness, pre-treatment and testing load on. the tribological characteristics have been studied. During the "Ring on-Disk" testing period silica-gel was used to remove the effect of humidity. As a result, increasing the film thickness revealed prolonged wear life, in the case or reasl the testing loads the dynamic friction coefficient was decreased gradually but in regarding the wear life, an intermideate contact pressure (4kgf/mm${2}$) revealed the maximum value. In regarding the surface protuberance friction an intermediate value of area fraction (60%) revealed maximum wear life. In this paper, the qualitative model in regarding the variation of the friction coefficient andworn depth was presented.presented.