• 제목/요약/키워드: Fatigue criteria

검색결과 259건 처리시간 0.024초

근피로 유발 후 신장운동시 심부투열치료가 슬관절 위치감각에 미치는 영향 (An Influence Stretching Exercise with Ultrasound and Microwave Application Having on Knee Joint Position Sense after Induction to Muscle Fatigue)

  • 박장성;최은영;정화수
    • 대한임상전기생리학회지
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    • 제8권1호
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    • pp.37-42
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    • 2010
  • Purpose : This study will recognize about the influences that stretching exercise with ultrasound and microwave application has on a knee joint position sense after induction to muscle fatigue. Methods : The object by each ten people divided at random thirty physical healthy adult men to constant group 1, group 2, group 3 to the objects. Treadmill exercised for induction to muscle fatigue, and let an exercise intensity decided on 85% of the maximum heart beat number with the goal heart beat number, and you exercise. Goal heart beat number measured as used heat rate monitor, and measured a oneself at the scale in order to recognize own physical state after end treadmill exercise to all objects to criteria to evaluate an ability shown in case of sports. Knee joint position sense used a N-K table, and experimenter did so as adaptation got passively arbitrary three angle done, and to order an original position. The object carried in person out one angle that experimenter designated, and measured repeatedly an error along him to this three times after being so. Rear before induction to muscle fatigue a position sense and measured after stretching exercise application, and played. Stretching exercise after induction applied stretching exercise, stretching exercise with ultrasound, stretching exercise with microwave, and applied to each group 1, group 2 and group 3 to muscle fatigue. Results : The result each group the difference which considers does not come out it was not but, improvement of the position sense is the possibility of knowing was from group 1, group 2 and group 3. Conclusion : These findings stretching exercise and stretching exercise with ultrasound and microwave after induct ion give help to a position sense elevation, and execute stretching exercise, and be effective against damage prevention by physical insecurity to muscle fatigue, and look.

Wind spectral characteristics on fatigue responses of towerbase and moorings of a floating offshore wind turbine

  • Udoh, Ikpoto E.;Zou, Jun
    • Ocean Systems Engineering
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    • 제9권2호
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    • pp.191-218
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    • 2019
  • The tower-platform interface and mooring system of floating offshore wind turbines (FOWTs) are some of the most critical components with significant influences on overall project costs. In addition to satisfying strength requirements, it is typical and vital to meet fatigue criteria for a service life of 25 years or more. Wind spectra characteristics considered in analysis can penalize fatigue designs, leading to unnecessary costs. The International Electrotechnical Commission (IEC, 2009) recommends the use of site-specific wind data (spectrum, turbulence intensity, etc.) in design of FOWTs, but for offshore sites it is often the case that such data is unavailable and land-based data are used as surrogates in design. For such scenarios, it is worth investigating whether such alternative approach is suitable and accurate, and understanding the consequence of the selection of wind spectral characteristics on fatigue design. This paper addresses the impact of the subsequent selection on fatigue responses of towerbase and mooring system in a FOWT, as a sequel to the paper by Udoh and Zou (2018) which focused on impacts on strength design. The 5 MW semi-submersible FOWT platform with six mooring lines implemented in the preceding study is applied in analysis. Results indicate significant variations in resulting fatigue life with considered wind parameters. Thus, it is critical to apply proper wind spectra characteristics for analysis and design of FOWTs to avoid unnecessary conservatism and costs. Based on the findings of this study, more explicit guidance on the application of turbulence intensities for IEC-recommended models in offshore sites could lead to more accurate load estimates in design of FOWTs.

운전이력을 고려한 지역난방 열배관의 피로수명 평가 및 최적화 (Fatigue Life Evaluation and Optimization for District Heating Pipes Considering Operating Temperature Transition Data)

  • 안민용;정성욱;이상민;장윤석;최재붕;김영진;김상호;김연홍
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.581-584
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    • 2005
  • A district heating(DH) system supplies environmentally-friend heat and is appropriate for reduction of energy consumption and/or air pollutions. The objectives of this paper are to systematize data processing of transition temperature, investigate its effects on fatigue life of DH pipes and optimization for size of DH pipes. A relational database management system as well as reliable fatigue life evaluation procedures is established for Korean DH pipes. Also, since the prototypal evaluation results satisfied both cycle-based and stress-based fatigue criteria. Through the optimum design process, the cross section diminished 18.64% and the CUF diminished 23.35%. So, it can be used as useful information in the future for optimal design, operation and energy saving via setting of efficient condition and stabilization of water temperature.

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

  • 이동항;이관호
    • 한국산학기술학회논문지
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    • 제14권5호
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    • pp.2511-2515
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    • 2013
  • 본 아스팔트 바인더의 피로균열 및 저온균열 특성을 개선하기 위하여 페타이어 열분해 공법의 부산물인 카본블랙을 이용하였다. 원아스팔트에 열분해 카본블랙 0%, 5%, 10%, 15% 및 20%를 혼합하였고, 동적전단유동기시험 및 처짐보유동기시험을 시행하였다. 열분해 카본블랙을 혼합한 아스팔트 바인더의 피로균열이 감소하는 경향을 나타내었고, 저온에서의 균열은 -12도까지는 개선되었으나, -18도에선 기준을 초과하는 것으로 나타났다.

국제 철도 연맹 규정(UIC Code)에 따른 RCV 대차 프레임 구조 안전성 평가 (RCV bogie frame structure safety evaluation according to UIC Code)

  • 노상철;박지형;강신유
    • 산업기술연구
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    • 제43권1호
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    • pp.7-13
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    • 2023
  • Nowadays, traffic congestion is emerging as a major problem due to the rapid population growth and the increase in automobiles. The train is a convenient means of transportation that can efficiently solve these problems. Trains have been developed in line with human aspirations for a long time, but research on safety is still insufficient. This study aims to check safety by conducting static tests and fatigue tests on bogie frames, and to help develop bogie frames in the future. For the static test, a strain gauge was attached to the point where the local stress concentration was expected beforehand, and the result value was derived, compared with existing theories, and expressed as a Goodman diagram. In the fatigue test, a total of 10 million loads were applied over three stages, and no cracks appeared in the non-destructive test conducted after each stage. Both tests were conducted according to the strict test method of the bogie frame presented by the UIC Code. It satisfied both fatigue life and strength evaluation criteria and was judged to be a bogie frame usable for safe train production.

한의학 교육에서 내상발열(內傷發熱) 증례를 이용한 표준화환자 프로그램 개발 연구 (Developing a Standardized Patient Program using Internal Damage Fever Cases in Korean Medical Education)

  • 조학준;조나영
    • 대한한의학원전학회지
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    • 제33권4호
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    • pp.33-56
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    • 2020
  • Objectives : The objective of this paper is to develop a standardized patient program with a focus on diagnosis and treatment of internal damage fever in Korean Medical education. Methods : First, cases of diagnosis and treatment of internal damage fever were collected from various classical texts, then a module was developed according to pre-existing standardized patient program's protocols based on selected cases. Careful consideration was given to developing evaluation criteria on history taking and physical examination that are necessary to accurately differentiating the 9 types. Results : Nine types of differentiation models on internal damage fever were selected, which are qi deficiency from overexertion/fatigue and famish; blood deficiency from overexertion/fatigue, famish and fullness; fire stagnation from excessive eating and cold foods; food damage; yang deficiency; yin deficiency; phlegm; stagnated blood; liver qi stagnation. For each type, evaluation criteria in regards to history taking, physical examination, communication with patient, and patient education were developed. Conclusions : When developing a standardized patient program using internal damage fever cases, it would better reflect the characteristics of Korean Medicine in clinical education of Korean Medicine if the program is based on classical texts. It would also be useful in evaluating students' graduation competence in exams such as CPX.

교번흐름 조건에 따른 토목섬유 필터층의 재료분리 및 지오텍스타일의 피로영향 분석 (Fatigue Effect and Particle Rearrangement of Geosynthetics Filter Layer with Cyclic Flow Conditions)

  • 오영인;유전용;김현태
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2005년도 춘계 학술발표회 논문집
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    • pp.1554-1561
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    • 2005
  • Geotextiles form one of the two largest groups of geosynthetics and it is consisted two major types of synthetic material (Woven, Non-woven). The functions of geotextiles are separation, reinforcement, filtration, drainage and as a moisture barrier. Within these functions, however, there are a large number of applications or use areas. Although the many research scholar and engineer developed and established the design criteria and construction methodology of geosynthetics filter layer, because the lack of suitable design terminology and uncertainty of long term durability, sustainable research still needed for optimum design methodology to the complicate field conditions. Especially, more intensive research needed about under the cyclic flow condition and fine silty sand base material. In this paper, the filter model test performed under cyclic flow with various boundary conditions (period and frequency of cyclic flow, types of geosynthetic filter material, surcharge etc.).

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실습선 승선기간에 의한 승선 집단별 피로도 분석에 관한 연구 (A Study on the Fatigue Analysis by the Boarding Period on Training Ship)

  • 김승연;박유진;이윤석
    • 해양환경안전학회지
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    • 제22권2호
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    • pp.160-166
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    • 2016
  • 승무원의 피로는 해양사고의 주요 원인으로 인식되고 있다. 해양사고 원인의 대부분을 차지하는 인적오류를 예방하기 위한 다양한 방안이 강구되고 있으나 인적요인에 직접적인 영향을 미치는 승무원의 피로에 관한 체계적인 연구는 아직 미흡한 실정이다. 본 연구는 교원 학생 직원, 그리고 남성 여성과 같이 다양한 승선경력 및 업무 형태를 가지고 있는 실습선 한바다호 승무원 128명을 대상으로 87일간의 해양실크로드 항해탐험 동안 이들의 피로도 변화를 분석하였다. 승선기간에 따른 승무원의 피로도 변화는 설문조사와 간호사의 개별 면담을 통해 이루어졌고, 수집된 데이터는 정량적인 통계 처리를 실시하여 피로도 요인으로 분류한 후, 승선 집단별로 피로도 요인의 변화를 비교하였다. 연구 결과 승무원의 피로도 요인은 정신적 피로도, 생리적 피로도, 신체적 피로도로 분류되었고, 승선기간에 따른 직위별, 성별 피로도 변화에 대한 반복측정 분산분석 결과, 직위별로는 교수 부원 집단이 학생 집단보다 정신적, 신체적 피로도를 더 많이 느끼는 것으로 나타났고, 성별로는 여성 승무원이 남성 승무원에 비해 신체적 피로도를 더 많이 느끼는 것으로 나타났다.

KTX 운행현황을 고려한 고속선 레일 연마 기준 정립에 대한 연구 (Study on the Establishment of Rail Grinding Criteria of High-Speed Railway Lines Considering the KTX Operation Circumstances)

  • 김만철;강태구
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 추계학술대회 논문집
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    • pp.377-385
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    • 2007
  • The importance of maintenance of rail surface defects is increasing more according to the KTX operation. That is because during high speed operation of rolling stock, rail surface defects may cause shortened fatigue life of rail, acceleration of track degradation and reduced ride comfort. The paper was intended to study the establishment of rail grinding criteria of high-speed railway lines considering the KTX operation circumstances. For this, the specimens of UIC 60 rail on Kyeong-Bu high-speed operation lines were collected and they were analyzed for metallographic structure and tested for the hardness. By analyzing the test results to the factors affecting the RCF causing the defects of rail surface, the study suggested the rail grinding criteria of the domestic high speed railway lines. As the factors affecting RCF, passing tonnage, running speed and track condition are considered.

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석유화학 플랜트 배관계의 응력 및 진동 평가와 적용에 관한 연구 (A Study on Stress and Vibration Evaluations and Application of Piping System in Petrochemical Plant)

  • 민선규;최명진;장승호
    • 한국공작기계학회논문집
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    • 제11권3호
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    • pp.110-116
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    • 2002
  • Here are shown on stress and vibration evaluations and application of piping system in petrochemical plant with and actual example. While stress evaluation by thermal growth has no argument on the calculated results, vibrational evaluations have some different results in accordance with the evaluation methods. In case of the static stress evaluation the ASME B3l.3 code defines 7000 cycles of fatigue lift: in operating the piping system with a design condition. However, the method of vibrational evaluation on piping systems in petrochemical plants has not been established clearly, yet. In this stuffy, it is purposed to present the requirement of a vibrational evaluation method for petrochemical plant piping system, with an actual application.