• 제목/요약/키워드: Central fatigue

검색결과 113건 처리시간 0.026초

귀비탕과 그 변방의 만성피로증후군 증상완화에 대한 효용성: 체계적인 문헌고찰 (Is Gwibitang and its modification beneficial for alleviating symptoms in chronic fatigue syndrome: A systematic review and meta-analysis)

  • 남동현
    • 대한한의학방제학회지
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    • 제28권2호
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    • pp.199-209
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    • 2020
  • Objectives : The purpose of this systematic review is to confirm whether Gwibitang is beneficial in chronic fatigue syndrome (CFS). Methods : Clinical trials were searched from databases including Pubmed, Embase, Central Cochrane, CNKI, Wanfang, CQVIP, CiNii, OASIS, Koreamed, and NDSL. The eligible study design was limited into randomized controlled trial, quasi-randomized controlled trial and controlled clinical trial. The outcomes included general effectiveness as nominal scale, and fatigue severity, insomnia severity and quality of life as interval or ratio scale. The meta-analysis and assessment of risk of bias was performed based on the data extracted from the selected trials. Results : The results of eight randomized controlled trials (n=596) were included in the meta-analysis. The results of the synthesis showed Gwibitang is beneficial substantially for relieving and managing the general symptoms, and its heterogeneity was not in important level (RR 0.26 [95% CI 0.17, 0.39], Z=6.47, P<0.00001, I2=0%). Gwibitang was beneficial for alleviating fatigue (SMD -0.78 [95% CI -1.27, -0.30], Z=3.17, P=0.002), but its certainty was low. In case of insomnia, too few trials had been found and their risk of bias was substantial, so no conclusions had been brought to. Conclusions : We found an evidence that Gwibitang could be beneficial for managing and alleviating main symptoms in CFS patients.

자동차 브레이크 부품용 S45C 소재의 레이저 용접특성 평가 (Laser Welding Properties of the S45C using Automobile Brake Parts)

  • 심기중;조원용;김용관;최규재
    • 한국자동차공학회논문집
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    • 제22권1호
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    • pp.103-109
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    • 2014
  • This paper represents the s-cam manufacturing process with the high-carbon steel like S45C using laser welding system. Laser welding of the high-carbon steel is generally difficult because of hardening of the weld zone. Also, existing s-cam manufacturing process, electric resistance welding system, have some problems like increase of production and development cost. To solve those problems, we are introduced the laser welding system with the pre-heating system for precision welding of s-cam with separated shaft and cam part. S-cam manufactured with optimum laser welding conditions is verified the performance like tensile strength, torsional strength and fatigue test. Strength and fatigue test results are described.

고무차륜형 AGT 주행장치의 진동피로해석 (Vibration Fatigue for the Bogie frame of the Rubber Wheel AGT)

  • 유형선;윤성호;변상윤;편수범
    • 한국철도학회논문집
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    • 제3권3호
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    • pp.117-124
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    • 2000
  • The rubber wheel-type AGT has two major kinds of bogie; one is the bogie type and the other steering one. Both are important vehicular structure to support the whole running vehicle and passenger loads. This paper deals with the static analysis for the two types of bogie frame subjected to combined external forces, as well as independent ones specified in UIC 515-4. Furthermore, the dynamic analysis is performed under vibrational loading conditions so as to compare dynamic characteristics, Numerical results by using commercial packages, I-DEAS and NASTRAN show that maximum stresses do not exceed the yield strength level of material used for both bogies. From an overall viewpoint of strength, the bogie type turns out to be superior to the steering type except for the case of a lateral loading. It is also observed that the steering type shows a characteristics of low frequency behavior during a course of searching for structurally weak areas to be stiffened. The vibrational fatigue analysis for each bogie frame depends on the loading time history conditions which is applied. Time History Central Database List in the NASTRAN package. Subsequent1y, the fatigue life of bogie type is longer than the steering type.

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레일체결장치용 방진패드의 피로거동에 관한 해석적 연구 (Analytical Study on Fatigue Behavior of Resilient Pad for Rail Fastening System)

  • 최정열
    • 문화기술의 융합
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    • 제7권2호
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    • pp.405-410
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    • 2021
  • 본 연구에서는 레일체결장치용 방진패드의 사용수명 및 스프링강성을 평가하고자 비선형 재료모델 및 피로하중조건을 적용한 유한요소해석을 수행하였다. 피로해석 결과, 초기조건 대비 스프링강성의 변화율은 약 16%로 나타나 피로경화가 발생된 것으로 분석되었다. 방진패드의 길이방향으로 발생되는 응력은 중앙부와 외곽부(Edge)의 발생응력의 차이가 약 10배 이상 발생되었다. 또한 중앙부 보다 외곽 경계부의 등가응력이 2배 이상 크게 발생하는 것으로 분석되었다. 따라서 실제 사용조건에서 방진패드의 손상 및 변형 취약부는 방진패드의 모서리부분인 것으로 분석되었다. 피로해석을 통해 산출된 반복횟수에 따른 방진패드의 등가응력을 이용하여 방진패드의 피로수명선도를 도출하였다. 본 연구에서 도출한 방진패드의 피로수명선도를 이용하여 향후 다양한 하중조건에서 방진패드의 등가응력을 산출하여 해당조건에서의 피로수명을 예측하는 데에 활용이 가능할 것으로 판단된다.

홍삼 섭취가 유.무산소성 운동수행능력과 중추 및 말초피로에 미치는 영향 (Effects of red ginseng supplementation on aerobic.anaerobic performance, central and peripheral fatigue)

  • 윤성진;김기형;김창주;박해찬;강경희;김무정;강성목;곽욱헌;김형준
    • Journal of Ginseng Research
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    • 제32권3호
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    • pp.210-219
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    • 2008
  • 본 연구는 8주간의 홍삼 투여가 중추피로 및 말초피로에 미치는 영향과 홍삼 투여와 지구성 트레이닝을 병행 했을 경우, 홍삼이 유 무산소성 운동수행능력에 미치는 영향을 관찰하였다. 그 결과 홍삼 섭취와 지구성 트레이닝을 병행하는 것이 홍삼 섭취와 지구성 트레이닝을 단독으로 적용하는 것 보다 유산소성 운동수행능력과 말초피로에 높은 효과를 기대할 수 있으며, 홍삼의 섭취가 중추피로에도 긍정적인 영향을 미칠 것으로 기대된다. 하지만, 무산소성 운동수행능력에는 큰 영향을 주지 못하는 것으로 생각된다. 이에, 본 연구를 통해 검증된 홍삼의 피로회복 및 운동수행능력 향상 효과는 추후 일반인뿐만 아니라 운동선수의 운동능력향상 보조물(Ergogenic aid)로써 도움을 줄 것으로 기대된다.

다발성 경화증의 물리치료 (Physical Therapy for Multiple Sclerosis)

  • 김영민
    • 대한물리치료과학회지
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    • 제2권2호
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    • pp.533-544
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    • 1995
  • Multiple sclerosis is a chronic, pregressive, demyelinating, disease of the central nervous system. It is named for the formation of disseminated scarlike lesions primarily in the central white mattrer of the brain and spinal cord. These plaques are commonly found in the regions of the optic tracts, third and fourth ventricles, basal ganglia, midbrain, pons, and spinal cord. Multiple sclerosis is an unpredictable disease, typically presenting with an exacerbating-remitting course, although other clinical courses have been recognized. Common clinical findings include disturbances in sensation, muscle strength, tone, fatigue, coordination, vision, communication, bladder and bowel function, and cognitive and behavioral function. Physical therapy of the patient with multiple sclerosis is centered around decreasing symptoms, improving function, prevention secondary complications, and promoting successful psychological adjustment. It requires the comprehensive efforts of a health care team to provide coordinated and continuing care.

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듀얼 레일 형상에 적합한 철도차량의 차륜 형상 설계 (Design of Railway Vehicle Wheel Profile Suitable for Dual-rail Profile)

  • 변성광;이동형;최하영
    • 한국기계가공학회지
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    • 제16권3호
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    • pp.30-37
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    • 2017
  • When a wheel profile of a train-tram is designed, both train and tram tracks should be considered. This study designed a wheel profile that enables high-speed driving(200km/h) on the train track and low speed driving on the tram track with multiple sharp curves. The study used the approximation optimization method to reduce cost and time, used the sequential quadratic programming method as the optimized algorithm, and the central composite design and response surface method as an approximate model. The optimized wheel shape based on this approximation optimization method reduced wear of the initial wheel showed a better performance in terms of derailment and lateral force.

Studies on the Performance of Self Healing of Plastic Cracks Using Natural Fibers in Concrete

  • Saraswathy, Velu;Kwon, Seung-Jun;Karthick, Subbiah
    • 한국건설순환자원학회논문집
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    • 제2권2호
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    • pp.115-127
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    • 2014
  • Addition of fibers in cement or cement concrete may be of current interest, but this is not a new idea or concept. Fibers of any material and shape play an important role in improving the strength and deformation characteristics of the cement matrix in which they are incorporated. The new concept and technology reveal that the engineering advantages of adding fibers in concrete may improve the fracture toughness, fatigue resistance, impact resistance, flexural strength, compressive strength, thermal crack resistance, rebound loss, and so on. The magnitude of the improvement depends upon both the amount and the type of fibers used. In this paper, locally available waste fibers such as coir fibers, sisal fibers and polypropylene fibers have incorporated in concrete with varying percentages and l/d ratio and their effect on compressive, split, flexural, bond and impact resistance have been reported.

관능검사(官能檢査)에 관(關)한 연구(硏究) -[제2보(第2報)] 3각1대비교법(3角1對比較法)에 대하여- (Studies on Sensory Evaluation -[Part II] Trio Paired Comparison-)

  • 홍진
    • Applied Biological Chemistry
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    • 제20권3호
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    • pp.270-278
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    • 1977
  • In case of sensory evaluation with multi-samples and long-period, in spite of using method with good sensitivity, quality differences among samples could net be detected well because of panel's fatigue and tiredness. So new method to reduce panel's sense of psychological and physiological responsibility, "Trio Paired Comparison", is designed, and New Modified Scheffe's Method 2 as the statistical method for a test of "Trio Paired Comparison" is proposed. And also in this paper problems and countermeasures in applicating "Trio Paired Comparison" are considered.

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