• Title/Summary/Keyword: Reliability impact

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Particle Impact Damage behaviors in silicon Carbide Under Gas Turbine Environments-Effect of Oxide Layer Due to Long-Term Oxidation- (세라믹 가스터빈 환경을 고려한 탄화규소의 입자충격 손상거동-장기간 산화에 따른 산화물층의 영향-)

  • 신형섭
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.4
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    • pp.1033-1040
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    • 1995
  • To simulate strength reliability and durability of ceramic parts under gas turbine application environments, particle impact damage behaviors in silicon carbide oxidized at 1673 K and 1523 K for 200 hours in atmosphere were investigated. The long-term oxidation produced a slight increase in the static fracture strength. Particle impact caused a spalling of oxide layer. The patterns of spalling and damage induced were dependent upon the property and impact velocity of the particle. Especially, the difference in spalling behaviors induced could be explained by introducing the formation mechanism of lateral crack and elastic-plastic deformation behavior at impact sit. At the low impact velocity regions, the oxidized SiC showed a little increase in the residual strength due to the cushion effect of oxide layer, as compared with the as-received SiC without oxide layer.

Statistical analysis of the energy for cable cutting (케이블 절단에 필요한 에너지 통계적 분석)

  • Choi, Chang-Sun;Kang, Won-Kyu
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.11a
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    • pp.400-403
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    • 2011
  • We performed Instron and Impact tests to estimate necessary explosive charge weight for cutting the cable whose diameter is 22 mm. The cutting energy measured by Instron was 21.3 J. Impact test were performed 8 times each at 5 different energies. The Impact test results were analysed by Probit methods. The cutting energy was calculated 37.7 J with 99.99% probability at 99% confidence, which is roughly equivalent to 250 mg of Zirconium potassium Perchlorate (ZPP).

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Design for Improving Impact Resistance of Microwave Oven Using Drop/Impact Analysis (낙하/충격해석을 통한 전자렌지의 내충격설계)

  • Kim, J.G.;Kim, J.Y.;Kim, H.S
    • Journal of Power System Engineering
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    • v.13 no.3
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    • pp.53-58
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    • 2009
  • The importance of cost reduction has grown bigger to ensure the competetive power of products in the electric home appliances industry. Thus, it is necessary to assess the reliability due to drop-impact happenning in process of distribution of microwave ovens with the panel and cavity of thinner thickness for cost reduction. In the present study, the drop/impact simulation using the explicit code LS-DYNA3D has been carried out for improving the impact resistance of a microwave oven. This CAE-based design approach can be successfully applied to enhance the deteriorated dynamic behavior under the impact conditions of dropping height 70cm according to ISTA procedure 2A.

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Improvement of Service Tree Analysis Using Service Importance (서비스 중요도를 사용한 서비스나무분석의 개선)

  • Park, Jong Hun;Hwang, Young Hun;Lee, Sang Cheon
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.40 no.2
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    • pp.41-50
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    • 2017
  • The purpose of this paper is to improve the service tree analysis introduced recently by Geum et al. [15]. Service tree analysis structures the service based on the customer participation perspective and provides a qualitative analysis method categorizing the service elements on the basis of its impact to top service. This paper attempts to apply the concept of reliability importance to the service tree analysis as a perspective of quantitative analysis, which is considered little in Geum et al. [15]. Reliability importance is a measure of the structural impact of the components that make up the system on the system lifetime in reliability engineering field and often used in fault tree analysis. We transform the reliability importance into service importance in accordance with service tree analysis, so that the influence of service elements on the service can be judged and compared. The service importance is defined as the amount of change of the service according to the change of the service element, therefore, it can be utilized as an index for determining a service element for service improvement. In addition, as an index for paired service elements, the relationship between the two service components can be measured by joint service importance. This paper introduces conceptual changes in the process of applying reliability importance to service analysis, and shows how to use the service importance for identifying the priority of service element for the final service and improving customer satisfaction through an example. By using the service importance and joint service importance in service tree analysis, it is possible to make efficient decision making in the process of determining the service elements for analyzing and improving the service.

The Impact of Artificial Intelligence Adoption in Candidates Screening and Job Interview on Intentions to Apply (채용 전형에서 인공지능 기술 도입이 입사 지원의도에 미치는 영향)

  • Lee, Hwanwoo;Lee, Saerom;Jung, Kyoung Chol
    • The Journal of Information Systems
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    • v.28 no.2
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    • pp.25-52
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    • 2019
  • Purpose Despite the recent increase in the use of selection tools using artificial intelligence (AI), far less is known about the effectiveness of them in recruitment and selection research. Design/methodology/approach This paper tests the impact of AI-based initial screening and interview on intentions to apply. We also examine the moderating role of individual difference (i.e., reliability on technology) in the relationship. Findings Using policy-capturing with undergraduate students at a large university in South Korea, this study showed that AI-based interview has a negative effect on intentions to apply, where AI-based initial screening has no effect. These results suggest that applicants may have a negative feeling of AI-based interview, but they may not AI-based initial screening. In other words, AI-based interview can reduce application rates, but AI-based screening not. Results also indicated that the relationship between AI-based initial screening and intentions to apply is moderated by the level of applicant's reliability on technology. Specifically, respondents with high levels of reliability are more likely than those with low levels of reliability to apply for firms using AI-based initial screening. However, the moderating role of reliability was not significant in the relationship between the AI interview and the applying intention. Employing uncertainty reduction theory, this study indicated that the relationship between AI-based selection tools and intentions to apply is dynamic, suggesting that organizations should carefully manage their AI-based selection techniques throughout the recruitment and selection process.

Study on the Effect of Message Sidedness on Brand Attitudes of Luxury Fashion Brands Regarding Eco-Friendly Activities: The Moderating Role of Regulatory Focus (럭셔리 패션브랜드의 친환경 활동에 대한 메시지 측면성이 브랜드 태도에 미치는 영향 연구: 조절초점의 역할을 중심으로)

  • Hye Yeon Jeong;Ho Jung Choo
    • Fashion & Textile Research Journal
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    • v.26 no.3
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    • pp.251-264
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    • 2024
  • This study identified the structural impact relationships, mediated by information reliability and brand authenticity, of different types of environmental messages from the perspective of luxury fashion brands, leading to formation of brand attitudes. Additionally, the study investigated how the impact of message sidedness on the formation of information reliability and brand authenticity varies according to consumers' regulatory focus tendencies. Data were collected through online surveys targeting individuals from Generation MZ, utilizing a professional research firm. A total of 300 respondents (150 for one-sided scenarios and 150 for two-sided scenarios) were selected. The collected data were validated using SPSS and AMOS. The following results were obtained. First, message sidedness influenced information reliability and brand authenticity, both of which demonstrated positive effects on brand attitude as mediating factors. However, message sidedness did not directly affect brand attitude. Second, consumers with both promotion and prevention focus tendencies perceived higher information reliability in two-sided message scenarios, and the perception difference in information reliability based on message sidedness was more pronounced among consumers with a prevention focus. Additionally, consumers with a prevention focus did not show a significant difference in brand authenticity between one- and two-sided message scenarios, while consumers with a promotion focus demonstrated an increase in brand authenticity in two-sided message scenarios compared to one-sided ones.

Selection of the standard impact sounds similar to the human impact sounds in reinforced concrete floors (실충격음과 표준충격원으로 발생된 바닥충격음의 비교)

  • Sato, Shin-Ichi;Lee, Pyoung-Jik;Jeon, Jin-Yong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.1167-1172
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    • 2007
  • This study investigates human floor impact sounds; not only the children's jumping and running represented by heavy-weight impact source such as bang machine and impact ball but also the high-heel walking and the light weight object dropping represented by tapping machine in the standard measurements. However, due to reliability problems as a standard impactor, bang machine has not been included in the new draft of ISO 10140 Part 3: Measurement of impact sound insulation. Therefore, the procedure to convert the floor impact sound level of the bang machine into that of the impact ball has been demanded because the bang machine has been only the standard heavy-weight standard impact source and much of its data has been collected, This study indicates that the use of impact ball is reliable and that the bang machine data can be successfully converted into the impact ball data in case of box-frame type reinforced concrete structures.

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Variation of reliability-based seismic analysis of an electrical cabinet in different NPP location for Korean Peninsula

  • Nahar, Tahmina Tasnim;Rahman, Md Motiur;Kim, Dookie
    • Nuclear Engineering and Technology
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    • v.54 no.3
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    • pp.926-939
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    • 2022
  • The area of this study will cover the location-wise seismic response variation of an electrical cabinet in nuclear power point (NPP) based on classical reliability analysis. The location-based seismic ground motion (GM) selection is carried out with the help of probabilistic seismic hazard analysis using PSHRisktool, where the variation of reliability analysis can be understood from the relation between the reliability index and intensity measure. Two different approaches such as the first-order second moment method (FOSM) and Monte Carlo Simulation (MCS) are helped to evaluate and compare the reliability assessment of the cabinet. The cabinet is modeled with material uncertainty utilizing Steel01 as the material model and the fiber section modeling approach is considered to characterize the section's nonlinear reaction behavior. To verify the modal frequency, this study compares the FEM result with recorded data using Least-Squares Complex Exponential (LSCE) method from the impact hammer test. In spite of a few investigations, the main novelty of this study is to introduce the reader to check and compare the seismic reliability assessment variation in different seismic locations and for different earthquake levels. Alongside, the betterment can be found by comparing the result between two considered reliability estimation methods.

A Study on Reliability Growth of P-3 Essential Avionic Equipments and Operational Availability Simulation (해상초계기 주요 항공전자장비 신뢰도 성장 분석 및 운용가용도 시뮬레이션)

  • Park, Jihoon;Ma, Jungmok
    • Journal of the Korea Institute of Military Science and Technology
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    • v.23 no.2
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    • pp.168-175
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    • 2020
  • Failure of essential avionic equipments have a significant impact on the operations and safety of P-3 maritime patrol aircraft. Therefore, avionic equipments of P-3 are required to have higher reliability. Based on the field failure data, this paper studies the reliability growth of essential avionic equipments in P-3 using Duane model. Additionally, a simulation model is built and implemented for identifying the operational availability according to the field failure data of avionic equipments.

Development of a Strut Mount with High Reliability by Improving Durability (내구성 향상을 통한 고 신뢰성 Strut Mount 개발)

  • Chung, Chan-Hong
    • Journal of Applied Reliability
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    • v.11 no.1
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    • pp.31-41
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    • 2011
  • A strut mount is an important part of vehicles which reduces the vibration and the impact transmitted from the wheels while supporting a shock absorber and a coil spring. Rubber compounding, shape design, and process design technologies are important components to improve the functionality of a strut mount such as durability, static, dynamic, and torsional characteristics. Among them the rubber compounding technology is the key technology which dominates the quality of a strut mount. In this study a strut mount with high reliability has been developed by adopting new rubber compounding and improving the shape of the inner plate and the isolator. Through the tests for prototypes it has been shown that the durability has been improved more than 2.5 times, from about 60,000 cycles to about 160,000 cycles.