• Title/Summary/Keyword: 피로 성능

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세계의 신형 전투함 현황 (1)

  • Gang, Dong-Gyun
    • Defense and Technology
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    • no.3 s.181
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    • pp.64-79
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    • 1994
  • TYPE 23 함정의 기본적인 주 임무는 대잠전의 탐색 능력을 극대화하기 위한 매우 정숙한 함정으로 잠수함에 의해 탐지되는 것을 피하고 함정의 수중 탐지 장비가 최적의 성능을 발휘할 수 있도록 해 주는데 있다.

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A Study on the Fatigue Characteristics and Life Prediction of the Tire Sidewall Rubber (타이어 사이드월 고무의 피로특성 및 수명예측에 관한 연구)

  • Moon, Byungwoo;Kim, Yongseok;Jun, Namgyu;Koo, Jae-Mean;Seok, Chang-Sung;Hong, Ui Seok;Oh, Min Kyeong;Kim, Seong Rae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.41 no.7
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    • pp.629-634
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    • 2017
  • In the case of the UHP (Ultra high performance) tire that the demand has increased rapidly, compared with the commonly used tire, severe deformation has been observed because of the low aspect ratio. When repeated deformations are applied to the sidewall rubber, accumulated fatigue damage may cause fatigue failure. Thus, the evaluation of the durability of the tire sidewall rubber has become a very important issue to prevent accidents that occur while the vehicle is running. However, the research and design criteria for the durability performance of the tire sidewall rubber hardly exist. In this study, we suggest a lifetime prediction formula using strain energy density obtained by performing tensile tests and fatigue tests on two different kinds of the tire sidewall compounds. Additionally, the applicability of our findings for low fuel consumption tires was reviewed by converting the fatigue life of the sidewall rubber into the expected mileage of the tire.

Development and Performance Analysis of Predictive Model for KOSPI 200 Index using Recurrent Neural Networks (순환 신경망 기술을 이용한 코스피 200 지수에 대한 예측 모델 개발 및 성능 분석 연구)

  • Kim, Sung Soo;Hong, Kwang Jin
    • Journal of Korea Society of Industrial Information Systems
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    • v.22 no.6
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    • pp.23-29
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    • 2017
  • Due to the success of Wealthfront, Betterment, etc., there is a growing interest in RoboAdvisor that is an automated asset allocation methodology globally. RoboAdvisor minimizes human involvement in managing assets, thereby reducing the costs of using services and eliminating human psychological factors. In this paper, we developed a predictive model for the KOSPI 200 Futures Index using deep learning, in order to replace the existing technical analysis technique. And the proposed model confirmed that When the KOSPI 200 Gift Index is small, it can be used to predict direction and price of index. In combination with the existing technical analysis, It is confirmed that the proposed models combining with existing technical analyses and can be applied to the RoboAdvisor Service in the future.

광커넥터의 성능저하 요인에 관한 고찰

  • An, Seung-Ho;Jeon, Oh-Gon;Jung, Meong-Young;Choi, Tae-Gu
    • ETRI Journal
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    • v.14 no.1
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    • pp.108-117
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    • 1992
  • 광통신 시스팀에서 신호접속용으로 사용되는 광커넥터의 결합기구 중 세라믹 페룰-슬리브의 정렬기구에서 발생하는 성능저하 현상을 다루었다. 성능저하 현상으로 페룰 단면연마시 발생하는 Vertex Eccentricty, 좌굴현상, 환경에 따른 탄성 및 응력의 변화, 마모, 피로파괴 등에 대한 이론적인 배경과 실험결과를 토대로 특성에 대한 영향을 분석하였다.

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An Evaluation of the Performance of Query Expansion Using Citation Information of Retrieved Documents (검색 문헌의 인용 분석을 통한 질의확장의 성능 평가 연구)

  • Yu, So-Young;Jung, Young-Mee
    • Proceedings of the Korean Society for Information Management Conference
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    • 2005.08a
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    • pp.305-310
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    • 2005
  • 이 연구에서는 주제검색을 통해 검색된 문헌들의 인용정보를 이용한 질의확장 기법을 제안하였으며 이 제안된 기법의 성능을 일반적 질의확장 기법인 지역적 질의확장 및 전역적 질의확장과 비교 평가하였다. 연구 결과 인용기반 질의확장 기법이 전역적 및 지역적 질의확장 기법에 비해 우수한 성능을 보임을 확인하였으며, 특히 피인용 표제어를 이용한 질의확장 검색의 효용성을 실험을 통해 밝혀냈다.

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Multilevel Secure Scheduler based on Two Version Two Phase Locking (2버전 2단계 로킹을 기반으로 하는 다단계 보안 스케줄러)

  • 유진호
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.6 no.1
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    • pp.61-82
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    • 1996
  • 데이타베이스 시스템의 다단계 보안을 위해 비밀 채널의 제거는 필수적인 것이다. 본 논문은 비밀채널<8>을 제거하고 성능향상을 위해 보안 2버전 2단계 로킹을 제안한다. 보안 2버전 2단계 로킹은 기본 2PL에 부가적으로 2개의 버전과 보안 요소를 고려한 것이다. 즉, 상위등급 트랜잭션 판독과 하위등급 트랜잭션 기록 사이의 충돌을 피하고 상위등급 판독연산과 동일등급 사이의 성능을 향상시키기 위한 방법이다. 기존의 보안 2단계 로킹기법과는 달리 2개 버전의 데이타와 희사기법을 사용하여, 데이타의 신선도가 떨어지지 않으면서 성능의 향상을 얻을 수 있게 한다.

Evaluation of Pyrolysis Carbon Black Modified Asphalt Binder for Fatigue and Low Temperature Crack (열분해 카본블랙을 이용한 아스팔트 바인더의 피로 및 저온 성능 평가)

  • Lee, Dong-Hang;Lee, Kwan-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.5
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    • pp.2511-2515
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    • 2013
  • Carbon black from pyrolysis of waste tires was used to modify and improve the fatigue properties and low temperature cracking of asphalt binder. 0%, 5%, 10%, 15% and 20% of pyrolyzed carbon black was mixed. Couple of laboratory tests, such as dynamic shear rheometer test and bending beam rheometer test, were carried out. The use of pyrolyzed carbon black decreased the fatigue at room temperature and improved the resistance of low temperature cracking up to $-12^{\circ}C$, but, was off the criteria at $-18^{\circ}C$.

Improvement of SNMP Performance using the Group Polling (그룹폴링을 이용한 SNMP 성능 개선)

  • 홍종준
    • Journal of the Korea Society of Computer and Information
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    • v.5 no.4
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    • pp.120-125
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    • 2000
  • SNMP(Simple Network Management Protocol) could have the overhead of network, if the number of the agent system which is managed by the management system is increased by the polling for the collection of network management information and the reply traffic for it. In this Paper, the polling method used in SNMP is improved, and Group Polling method is proposed. This can reduce the overhead of network, on case that the agent system is to be increased. The proposed method collects information by grouping agent systems, and have smaller reply latency time and communication overhead than the previous method. So if the number of agent system or the Polling count is numerous, the proposed method is more efficient. As the result of the prototype test, the increasement of agent system can have small variation of traffic and transmission delay time.

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Performance Evaluation Method for Facility Inspection and Diagnostic Technologies (첨단기술을 활용한 시설물 점검 및 진단 기술 검·인증을 위한 성능평가 방법론)

  • Lee, Young-Ho;Bae, Sung-Jae;Jung, Wook;Cho, Jae-Yong;Hong, Sung-Ho;Nam, Woo-Suk;Kim, Young-Min;Kim, Jung-Yeol
    • Journal of the Society of Disaster Information
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    • v.16 no.1
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    • pp.178-191
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    • 2020
  • Purpose: This paper proposes a performance evaluation method for state-of-the-art facility inspection/diagnostic equipment through a trend survey of equipment and standardization systems of US, Japan, and Korea. This paper also suggests the priority of developing a performance evaluation method through expert interviews and surveys. Method: In this study, report for the last 5 years of FMS, state-of-the-art equipment of facility maintenance companies/safety diagnosis specialist agencies and papers/research reports/patents of NTIS were analyzed to identify recent trends of facility inspection/diagnostic equipment usages. standardization system of US, Japan, and Korea were analyzed to figure out a suitable form of a performance evaluation method for the domestic situation. And expert interview and survey were conducted to identify the priority of developing a performance evaluation method. Result: The performance evaluation method must be developed by the shape that only evaluates performance, regardless of types of equipment, on inspection item level for creative technology development. The priority of developing the performance evaluation method was identified as crack detection of concrete for durability evaluation and displacement/deformation/fatigue detection of concrete and steel for stability evaluation. Conclusion: The performance evaluation method will be developed firstly for the crack detection of concrete for durability evaluation and displacement/deformation/fatigue detection of concrete/steel for stability evaluation. In order to promote creative technology development, the performance evaluation method should be developed in a form that provides standardized specimens or testbeds and can be applied regardless of types of technologies.

Variation of Fatigue Properties in Nanoskinned Ti-6Al-4V - Rotating Bending and Axial Loading Tension-Compression Cycle - (Ti-6Al-4V 재의 UNSM 처리에 의한 피로특성변화 - 회전굽힘 피로시험과 축하중 인장압축 피로시험 비교 -)

  • Suh, Min-Soo;Pyoun, Young-Shik;Suh, Chang-Min
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.4
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    • pp.443-449
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    • 2012
  • Nanoskins were fabricated on a Ti-6Al-4V material by carrying out various surface treatments, i.e., deep rolling, laser shot peening, and ultrasonic nanocrystal surface modification (UNSM). These surface treatments are newly developed techniques and are becoming more popular for industrial applications. Fatigue tests were carried out using material test system (MTS); these tests included the axial loading tension-compression fatigue test (R = -1, RT, 5 Hz, sinusoidal wave) and rotating bending fatigue test (R = -1, RT, 3200 rpm). The analysis of the crack initiation pattern in the UNSM-treated material indicated that the crack was interior originating in the axial loading tension-compression cycle, and was surface originating in the bending fatigue test. UNSM treatment significantly improved the fatigue strength for the regime of above $10^6$ cycles that S-N curve of rotating bending stress clearly show the performance of a 5 mm titanium specimen after UNSM treatment is similar to that of an untreated 6 mm titanium specimen.