• 한국지반공학회지:지반
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• 제12권6호
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• pp.37-50
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• 1996

본 연구는 국내 고속도로의 암반사면의 현장조사를 실시하여 암반사면의 붕괴형상 및 특징을 암종 및 지질구조에 따라 분류하였으며 사면의 암종에 따른 붕괴규모, 붕괴시기 등을 분류하고 불안정한 사면에 영향을 주는 주요 지질구조에 대해 분석하였다. 연구결과, 붕괴 빈도가 높은 사면은 한반도의 남동측에 나타나는 중생대 백악기 퇴적암층과 경기일원 및 강원도 일원의 비교적 넓게 분포하고 있는 선캠브리아기의 편마암, 편암지대에 분포하는 것으로 나타났다. 암종에 따른 붕괴유형은 화성암이 낙석, 평면파괴, 토층유실, 원호파괴의 붕괴유형을 보이나 붕괴빈도가 비교적 낮고 퇴적암에서는 평면파괴가 우세하게 나타났으며 계일층의 차별적인 풍화에 의해 붕락형의 붕괴유형을 보이기도 하였다. 그리고 변성암에서는 암질불량으로 인한 원형파괴, 단층구조 및 엽리 등으로 인한 쐐기파괴, 평면파괴양상을 보였다. 지질구조에 따른 붕괴는 퇴적암에서는 주로 층리에 의해서는 붕괴가 발생되었으며 화성암에서는 절리, 그리고 변성암에서는 단층과 암질불량에 의한 붕괴가 우세한 것으로 나타났다.

• 품질경영학회지
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• 제18권2호
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• pp.33-42
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• 1990

This paper proposes the maintenance model of multi-component system when the failure characteristics and types of components are considered. In this model, it is assumed that a system is composed of a critical component, a major component and a minor component. Also, failure types is classified into major failure and minor failure. If major failure occurs to critical component before system age replacement time, the system is renewed. If major failure does not occur until its age replacement time, preventive maintenance is performed at age replacement time T. Minimal repairs are carried out after each minor failure. Major component is minimal-repaired if any failure is discovered during operation. Minor component should be replaced as soon as any failure is found. This paper determines the optimal replacement time of the system which minimizes total maintenance cost. Numerical example illustrates these results.

• 산업경영시스템학회지
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• 제21권45호
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• pp.301-307
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• 1998

This paper proposes free warranty interval for repairable items when the failure types of item are considered. Failure types are classified into major failure and minor failure. If major failure occurs during warranty period, the item is replaced and if minor failure occurs during warranty period, the item is minimally repaired. This paper determines the optimum free warranty interval which minimizes total expected cost of the free warranty cost model. Numerical example is shown in which failure time of item has weibull distribution.

• 한국국방경영분석학회지
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• 제25권2호
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• pp.144-157
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• 1999

In this paper, we consider a new preventive replacement policy for the system which deteriorates while it is in operation with an increasing failure rate. The system is subject to two types of failure. A type 1 failure is repairable while a type 2 failure is not repairable. In the new policy, a system is replaced at the age of $t_p$ or at the instant the$\textsc{k}^{th}$ type 1 failure occurs, whichever comes first. However, if a type 2 failure occurs before a preventive replacement is performed, a failure replacement should be made. We assume that a type 1 failure can be rectified with a minimal repair. We also assume that a replacement takes a non-negligible amount of time while a minimal repair takes a negligible amount of time. Under a cost structure which includes a preventive replacement cost, a failure replacement cost and a minimal repair cost, we develop a model to find the optimal ($\textsc{k},t_p$) policy which minimizes the expected cost per unit time in the long run while satisfying a system availability constraint.

• 한국조리학회지
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• 제22권8호
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• pp.204-218
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• 2016

The purpose of this study is to identify the differences in the effect of service recovery efforts on consumers satisfaction, word of mouth intentions, and revisit intentions when exposed to service failure situations. The service failure situation was classified into outcome-related and process-related failures. The service recovery effort was divided into financial and emotional efforts. Using a scenario technique, this study collected data from diners in Daegu and Gyoungbuk province. The results of the empirical analysis show that the effect of service recovery efforts varies depending on types of service failures and recovery efforts. Also, the interaction between service failure types and service recovery efforts was confirmed.

• International Journal of Reliability and Applications
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• 제4권2호
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• pp.51-56
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• 2003

A k-out-of-n system with n identical and independent components is considered in which the components takes two types of function: 0 (open-circuit) or 1 (closed) on command (e.g. electromagnetic relays and solid state switches). Components are subject to two types of failure on command: failure to close or failure to open. In our k-out-of-n system, failure of (n-k)＋1 or more components to close causes to the close failure of the system, or failure of k or more components to open causes the open failure of the system. The long-run average cost rate is obtained. We find the optimal k minimizing the long run average cost rate for given n. A numerical example is presented.

• Journal of Mechanical Science and Technology
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• 제19권6호
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• pp.1280-1289
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• 2005

This paper presents the effects of corrosion environments of failure pressure model for buried pipelines on failure prediction by using a failure probability. The FORM (first order reliability method) is used in order to estimate the failure probability in the buried pipelines with corrosion defects. The effects of varying distribution types of random variables such as normal, lognormal and Weibull distributions on the failure probability of buried pipelines are systematically investigated. It is found that the failure probability for the MB31G model is larger than that for the B31G model. And the failure probability is estimated as the largest for the Weibull distribution and the smallest for the normal distribution. The effect of data scattering in corrosion environments on failure probability is also investigated and it is recognized that the scattering of wall thickness and yield strength of pipeline affects the failure probability significantly. The normalized margin is defined and estimated. Furthermore, the normalized margin is used to predict the failure probability using the fitting lines between failure probability and normalized margin.

• 한국수소및신에너지학회논문집
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• 제31권1호
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• pp.65-72
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• 2020

In this study, the purpose is to identify the risks of the facilities of packaged hydrogen stations. As a risk identification method, failure mode & effect analysis (FMEA), a qualitative risk assessment, was used to analyze failure mode and effects of component of each facility. The analysis criteria were used to derive the risk priority number (RPN) using the 5-point method according to severity, incidence, and detectability. The study analyzed a total of 141 components of 23 types that can be identified on the design of the packaged hydrogen filling station. As a result, 683 types of failures and their causes and effects were identified. and the RPN was number of a total of 1,485. Of these, 10 failure types with a RPN value of 40 or more were deemed necessary. In addition, a list of failure types with a severity score of 5 was identified and analyzed.

• The Journal of Advanced Prosthodontics
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• 제11권5호
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• pp.297-304
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• 2019

PURPOSE. This in vitro study investigated the repair bond strength of the zirconia ceramic after different aging conditions. MATERIALS AND METHODS. In order to imitate the failure modes of veneered zirconia restorations, veneer ceramic, zirconia, and veneer ceramic-zirconia specimens were prepared and were divided into 4 subgroups as: control ($37^{\circ}C$ distilled water for 24 hours ) and 3000, 6000, 12000 thermal cycling groups (n=15). Then, specimens were bonded to composite resin using a porcelain repair kit according to the manufacturer recommendation. The repair bond strength (RBS) test was performed using a universal testing machine (0.5 mm/min). Failure types were analyzed under a stereomicroscope. Two-way ANOVA and Bonferroni test were used for statistical analysis. RESULTS. The RBS values of zirconia specimens were statistically significant and higher than veneer ceramic and veneer ceramic-zirconia specimens in control, 3000 and 6000 thermal cycling groups (P<.05). When 12000 thermal cycles were applied, the highest value was found in zirconia specimens but there was no statistically significant difference between veneer ceramic and veneer ceramic-zirconia specimens (P>.05). Veneer ceramic specimens exhibited cohesive failure types, zirconia specimens exhibited adhesive failure types, and veneer ceramic-zirconia specimens exhibited predominately mixed failure types. CONCLUSION. Thermal cycling can adversely affect RBS of composite resin binded to level of fractured zirconia ceramics.

• 산경연구논집
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• 제9권7호
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• pp.19-32
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• 2018

Purpose - This paper aims at exploring the effects of failure types such as failure in promotion orientation and failure in prevention orientation on consumers' consumption behavior, and the moderation role of lay theories in the effects. Research design, data, and methodology - This study employed 2 between-subject designs(failure in promotion orientation vs. failure in prevention orientation) and also 2 (failure in promotion orientation vs. failure in prevention orientation) with implicit self as the within-subject. Chinese consumers participated in the empirical study, and to verify the hypotheses ANOVA, T-test and regression analysis were used. Results - Consumers were more likely to choose adaptive consumption behavior rather than compensatory consumption behavior when they were encountered with failure in promotion orientation versus failure in prevention orientation. Lay theories did play the moderation role in the effect of failure types on consumption behavior. The incremental theorists who think that effort is an important way to accomplish their learning goals showed more willingness to conduct compensatory consumption behavior rather than adaptive consumption behavior. Conclusions - Marketers should put more attention on the ways by which their products can help consumers self-improve when consumers encounter with failure. They should also be aware of the importance of consumers' mindsets when designing and developing advertising messages.