• 제목/요약/키워드: Central fatigue

검색결과 113건 처리시간 0.026초

해양환경의 변동성을 고려한 해상풍력터빈 지지구조물의 기대수명 평가 (Expected Life Evaluation of Offshore Wind Turbine Support Structure under Variable Ocean Environment)

  • 이기남;김동현;김영진
    • 한국해양공학회지
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    • 제33권5호
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    • pp.435-446
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    • 2019
  • Because offshore structures are affected by various environmental loads, the risk of damage is high. As a result of ever-changing ocean environmental loads, damage to offshore structures is expected to differ from year to year. However, in previous studies, it was assumed that a relatively short period of load acts repeatedly during the design life of a structure. In this study, the residual life of an offshore wind turbine support structure was evaluated in consideration of the timing uncertainty of the ocean environmental load. Sampling points for the wind velocity, wave height, and wave period were generated using a central composites design, and a transfer function was constructed from the numerical analysis results. A simulation was performed using the joint probability model of ocean environmental loads. The stress time history was calculated by entering the load samples generated by the simulation into the transfer function. The damage to the structure was calculated using the rain-flow counting method, Goodman equation, Miner's rule, and S-N curve. The results confirmed that the wind speed generated at a specific time could not represent the wind speed that could occur during the design life of the structure.

코로나바이러스감염증-19에서 나타나는 후미각손상의 특성과 한의학적 분석 (Features and Interpretation of Olfactory and Gustatory Disorders in the Corona Virus Disease-19)

  • 지규용
    • 동의생리병리학회지
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    • 제34권6호
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    • pp.309-318
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    • 2020
  • Besides respiratory infection, COVID-19 has many neurological symptoms not only loss of smell and taste but also fatigue and brain fog. But it is a challenge to treat the neurological symptoms especially of anosmia and ageusia. In order to search for the therapeutic methods, the geographical diversity and pathological mechanisms of the COVID-19 and two symptoms were investigated from the latest clinical studies. Because the environmental conditions of the monsoon climate zone of East Asia and the Mediterranean and Oceanic climate zone of Italy, Britain, United States and tropical Brazil are different, each of diverse etiology and internal milieu should be considered differently in the treatment. SARS-CoV-2 exhibits the dampness-like characteristics and the olfactory and gustatory disorders are particularly more common than other flu or cold. and it tends to show features of damaging the lung qi of olfaction and heart-spleen qi of gustation. The mechanisms of olfactory and gustatory loss are various according to precursory, inflammatory, non-inflammatory and sequelar forms, so the therapeutic method should be designed for each period and pathology. If the process of inflammation arises from nasal and respiratory, olfactory epithelium to the central nervous structure by way of blood brain barrier, the treatment should be corresponded with the stage and depth of pathogen place. And if the olfactory loss is asymptomatic or in the initial stage, it can be applied intranasal topical scent therapy to relieve temporary locking of qi movement, but maybe also used in parallel together with herbs of relieving dampness toxin latent in the lung parenchyma.

Investigation of Working Conditions and Health Status in Platform Workers in the Republic of Korea

  • Hyoungseob Yoo;Munyoung Yang;Ji-Hun Song;Jin-Ha Yoon;Wanhyung Lee;Jinhee Jang;Minjoo Yoon;Mo-Yeol Kang
    • Safety and Health at Work
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    • 제15권1호
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    • pp.17-23
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    • 2024
  • Background: The present study aimed to analyze several aspects of the working conditions and health status of platform workers in the Republic of Korea, such as ergonomic and emotional hazards. We also compared the health status of the platform workers with that of the general population. Methods: A total of 1,000 platform workers participated in this survey from August 7 to August 17, 2022. The participants included 400 designated drivers, 400 food-delivery drivers, and 200 housekeeping managers. A face-to-face survey with a structured questionnaire was conducted by researchers who had received specific instructions. The focus of the survey extended to the work environment, encompassing factors such as workplace violence, as well as physical, chemical, and ergonomic hazards. Health-related data for the previous year were also collected, covering a range of issues such as hearing problems, skin problems, musculoskeletal symptoms, headaches, injuries, mental health issues, and digestive problems. Subsequently, we compared the health symptom data of the responders with those of the general population in the Republic of Korea. Results: Platform workers, including designated drivers, food-delivery drivers, and housekeeping managers, existed in the blind spot of social insurance, facing frequent exposure to physical and chemical hazards, ergonomic risk factors, and direct or indirect violence. The prevalence of health problems, including musculoskeletal symptoms, general fatigue, and depressive symptoms, in each occupational group was statistically higher than that in the general population after standardization for age and gender. Conclusion: The results revealed unfavorable working environment and inferior occupational health of platform workers compared with those of the general population.

유리질 중합체의 균열 Healing에 관한 연구 (제1보) -이론 모델링- (A study on Crack Healing of Various Glassy Polymers (part I) -theoretical modeling-)

  • 이억섭
    • 한국정밀공학회지
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    • 제3권1호
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    • pp.40-49
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    • 1986
  • Crack, craze and void are common defects which may be found in the bulk of polymeric materials such as either themoplastics or thermosets. The healing phenomena, autohesion, of these defects are known to be a intrinsic material property of various polymeric materials. However, only a few experimental and theoretical investigations on crack, void and craze healing phenomena for various polymeric materials have been reported up to date [1, 2, 3]. This may be partly due to the complications of healing processes and lacking of appropriate theoretical developments. Recently, some investigators have been urged to study the healing phenomena of various polymenic materials since the significance of the use of polymer based alloys or composites has been raised in terms of specific strength and energy saving. In the earlier published reports [1, 2, 3, 4], the crack and void healing velocity, healing toughness and some other healing mechanical and physical properties were measured experimentally and compared with predicted values by utilizing a simple model such as the reptation model under some resonable assumptions. It seems, however, that the general acceptance of the proposed modeling analyses is yet open question. The crack healing processes seem to be complicate and highly dependent on the state of virgin material in terms of mechanical and physical properties. Furthermore, it is also strongly dependent on the histories of crack, craze and void development including fracture suface morphology, the shape of void and the degree of disentanglement of fibril in the craze. The rate of crack healing may be a function of environmental factors such as healing temperature, time and pressure which gives different contact configurations between two separated surfaces. It seems to be reasonable to assume that the crack healing processes may be divided in several distinguished steps like stress relaxation with molecular chain arrangement, surface contact (wetting), inter- diffusion process and com;oete healing (to obtain the original strength). In this context, it is likely that we no longer have to accept the limitation of cumulative damage theories and fatigue life if it is probable to remove the defects such as crack, craze and void and to restore the original strength of polymers or polymer based compowites by suitable choice of healing histories and methods. In this paper, we wish to present a very simple and intuitive theoretical model for the prediction of healed fracture toughness of cracked or defective polymeric components. The central idea of this investigation, thus, may be the modeling of behavior of chain molecules under healing conditions including the effects of chain scission on the healing processes. The validity of this proposed model will be studied by making comparisons between theoretically predicted values and experimentally determined results in near future and will be reported elsewhere.

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유산소운동이 여자 아동의 뇌세포 생성 관련인자에 미치는 영향 (Effect of Aerobic Exercise on Factors Relative to the Brain Nerve Growth in Girls)

  • 편미영;조한샘;전재영;김종원;이경희;임춘규;김태운;김현준;곽이섭;고기준
    • 생명과학회지
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    • 제20권6호
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    • pp.948-954
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    • 2010
  • 운동은 신경의 생성, 적응, 보호 기능을 통해 뇌 기능 및 생성에 긍정적인 영향을 미치며, 유산소운동은 뇌신경 성장인자(GH, IGF-1, estrogen, serotonin)를 변화시키는 것으로 보고되었다. 본 연구는 여자 아동의 뇌기능 발달 및 뇌세포 생성 유도인자의 유산소운동 효과를 알아보고자 유산소운동 프로그램에 따른 뇌신경 성장인자(GH, IGF-1, estrogen, serotonin)의 변화를 분석하여 다음과 같은 결론을 얻었다. 반복측정 분산분석에 의해 운동군과 대조군의 평균을 비교한 결과 유산소운동은 집단간 유의한 차이를 보이며 체중, BMI, 체지방량, 체지방률을 감소 시켰으며, 제지방률을 증가시켰다. 또한 뇌신경 성장인자인 serotonin을 감소시켰으며, GH와 IGF-1을 증가시켰다. 본 연구결과 유산소운동 프로그램이 아동의 체중, BMI, 체지방, 체지방률 감소와 제지방률 증가에 효과적이다. 또한 serotonin이 운동 후 감소된 결과를 볼 때 유산소운동 프로그램이 아동의 중추피로 감소에 효과적이며, GH, IGF-1의 운동 후 증가된 결과를 볼 때 유산소운동이 아동의 뇌기능 발달 및 뇌세포 생성 유도에 긍정적인 프로그램임을 알 수 있다.

인삼의 약리작용 (Pharmacological Action of Ginseng)

  • 홍사악;임정규;박찬웅;차인준
    • Journal of Ginseng Research
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    • 제3권1호
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    • pp.66-93
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    • 1979
  • Panax ginseng C. A. Meyer, which has been known for more than EWO years. occupies a Particular prince in folk medicine as so called tonic remedy. The pharmacolgical investigations of ginseng, based on the scientific concepts and methodology, have been performed by many researchers through the past 50∼60 years at different parts of the world. The pharmacological action of Panax ginseng compiled from the numerous reports can be summarized as follows: 1. On central nervous system, the effect of Panax ginseng is timulatory in smaller doses and somewhat depressive in larger doses. From the psychopharmacological aspect, ginseng seems to increase the mental efficiency of man. 2. Ginseng has the effect tending to Protect organism from various physical and chemical stresses. 3. The growth and basal metabolic rates of experimental animals are stimulated by ginseng. Ginseng also prolongs the survival time of animals under adverse influences. 4. Increasing the physical and mental efficiency, ginseng postpones the onset of fatigue and increases the working capacities. 5. In the case of the intravenous administration of ginseng, a transitory and slight hypotensive effect is observed. These hypotensive effects seems to include that of a direct action and actions related to the release of histamine and/or serotonin by ginseng. 6. It is Presumed that ginseng lowers the elevated bleed ingar and cholesterol level. 7. Ginseng tends to increase the gastrointestinal motizity and tone 8. It is presumed that ginseng Promotes the iron metabolism and activates the hematopoietic factors. 9. Ginseng tends to stimulate the biosynthesis of nucleic acid and release of histamine and serotonin. 10. The toxicity end adverse reactions of ginseng appear to be nothing that warrants apprehension. 11. Anticancer erects of ginseng seem to be due to indirect action rather than direct action on cancer cell, by improving the host condition 12. Recent clinical trials of ginseng harts obtained sent good results, but Present trial is still limited in its range, so it is necessary to broaden the scope of trial covering many kinds of organs and diseases. From the above, although it appears that substantial advancements have been achieved in the studies on the Pharmacological actions of Panax ginseng there are many discrepancies noticed in the reported data. Furthermore the precise mechanisms of actions of ginseng are sometimes obscure, even unknown in other actions as the students stand now. The main reasons for this are considered to be that even though saponin has been identified at one of the active substances of ginseng, other components have not fully been identified and that the experimental approaches of the investigations varied with different researchers. Thus a thorough analysis of the chemical components and newer standardized concepts and metohds appear to be the pre-requisites for further study of the pharmacolgical effects and mechaisms of Panax ginseng.

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EA 비즈니스 아키텍처 개념의 개방과 확대에 대한 제언 (Liberating and Reviving the Concept of EA Business Architecture)

  • 전성현
    • 정보화연구
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    • 제10권4호
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    • pp.435-449
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    • 2013
  • 정부와 공공부문을 중심으로 한 국내 EA 추진에 대한 평가는 복합적이다. 범 정부 차원의 국가정보화 거버넌스 체계로서의 EA에 대한 평가는 정보화 예산절감 등의 외형적 성과지표를 토대로 매우 긍정적으로 나타나는 반면 개별 부처와 기관의 실제 EA 추진 현장에서 관찰되는 EA에 대한 평가는 효용에 대한 실망과 제도적 강제에 대한 피로감 등이 혼재되어 나타난다. 본 연구는 이러한 개별 부처 기관의 EA에 대한 부정적 시각이 EA 기반 국가정보화 체계의 근간을 흔드는 잠재적 위험요소로 발전할 수 있음을 경계하고 그 원인과 해결의 단초를 엔터프라이즈가 가진 EA 비즈니스 아키텍처 개념에서 찾기를 제안한다. 구체적으로 현재 엔터프라이즈가 견지하는 EA 비즈니스 아키텍처에 대한 사고의 경직성을 지적하고 그 개념의 개방과 확대를 통해 비즈니스 아키텍처와 EA 전반에 대한 신뢰와 열정의 회복 가능성을 모색한다. 이를 위해 실제 EA 구축 현장에서의 관찰과 경험을 토대로 EA 비즈니스 아키텍처 개념을 구성하는 제반 개념적 축과 분기점들을 도출하고 각 축과 분기점에서 비즈니스 아키텍처 개념이 어떻게 개방 확대될 수 있는지를 모색한다. 아울러 이를 토대로 몇 개의 EA 비즈니스 아키텍처 개념 유형을 예시적으로 도출한다. 끝으로 이러한 EA 비즈니스 아키텍처 개념의 개방과 확대가 가진 이론적 실천적 의미와 시사점을 논하고 의의와 한계를 제시한다.

정신과적 관점에서의 섬유근통 (Fibromyalgia from the Psychiatric Perspective)

  • 이윤나;이상신;김현석;김호찬
    • 정신신체의학
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    • 제28권2호
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    • pp.99-107
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    • 2020
  • 섬유근통은 피로, 수면장애, 기분변화, 인지장애 및 만성 전신통증을 핵심 증상으로 하는 질환이다. 섬유근통은 유전적 취약성, 통증 처리과정 및 스트레스 반응 체계의 변화 등을 포함하는 생물학적 요인과 불안, 우울, 분노, 스트레스 등의 심리적 요인, 그리고 감염, 발열 질환, 외상 등의 환경적 요인이 함께 작용하여 발생하는 것으로 알려져 있으며, 핵심 병인으로 감각 자극이 인식되는 과정에서 증폭되어 통증이 증진되는 중추성 감작의 역할이 강조되고 있다. 가이드라인들은 개별 환자의 필요에 따라 선택된 다원적 접근을 권고하며, 임상의는 충분한 교육을 통해 지적 이해의 틀을 제공하고 자기 관리의 중요성을 강조해야 한다. 섬유근통에서 정신건강 문제의 유병률은 일반인구집단의 7~9배로 유의하게 높으며, 특정 정신병리 및 수면장애와의 관련성도 제기되고 있다. 정신과적 상태는 섬유근통과 양방향성 상호작용을 하며 경과에 영향을 주고, 취약성을 공유하며 서로의 위험 요인으로 작용할 수 있으므로, 동반질환을 면밀히 평가하여 보다 통합적인 관리가 필요할 것이다.

B급 감성 광고 경향에 관한 내용분석: 2015년부터 2020년까지 공중파 TV광고를 중심으로 (A Content Analysis of B-Class Emotional Advertising Trend: Focused on TV commercials from 2015 to 2020)

  • 백주연;염동섭
    • 한국융합학회논문지
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    • 제13권1호
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    • pp.179-188
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    • 2022
  • 본 연구는 B급 감성 광고에 대한 전반적인 특성을 파악하고 경향을 분석하는 것을 목적으로 하였다. 이를 위해 국내 최대 광고 포털 사이트인 TVCF(www.tvcf.co.kr)에 탑재된 광고들 중 2015년부터 2020년까지 온에어된 498편의 광고들을 추출하여 내용분석 방법을 통해 분석하였다. 분석결과, B급 감성 광고는 다양한 장르에서 활용되고 있으나 특히, 유머/과장 장르에서 가장 많이 활용되어왔고 2020년 Corona-19 Pandemic으로 인해 점차 증가하는 추세를 나타내고 있음을 알 수 있었다. 또한 상업광고가 아닌 비상업광고 영역인 관공서나 단체, 공익광고, 기업 PR 등의 영역에서 과거에 비해 B급 감성 광고 활용률이 증가되었음을 확인하였다. 이러한 결과는 B급 감성 광고는 이제 더 이상 단순히 '하위문화(subculture)'로부터 기인 된 '비주류' 문화의 표상이 아닌 사회적·문화적·경제적 현상뿐 만이 아니라 개인의 우울감, 피로감 그리고 상실감의 증폭 문제 등까지 '희화(漫畫)화'를 통해 완화시켜주는 '새롭고 도전적인 주류문화'의 표상으로서 산업/비산업군의 모든 영역까지도 널리 활용되고 있는 중추적 역할을 하고 있다는 사실에 주목할 필요가 있음을 시사한다.

과민성대장증후군의 형상의학적 고찰 -동의보감(東醫寶鑑)을 중심으로- (Hypersensitive Large Intestine Syndrome in Hyungsang Medicine)

  • 최병래;최영현;한진수;이용태
    • 동의생리병리학회지
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    • 제19권5호
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    • pp.1129-1136
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    • 2005
  • The writer reports the conclusions gained from study about the cause of the hypersensitive large intestine syndrome with Dongeuibogam as the central figure through researching the disharmony among Body Essence, Vital Energy, Mentality, and Blood, mutual action of five viscera and six bowels, and external shapes. The hypersensitive large intestine syndrome is generally chronic and recurred in many cases, so it is more efficacious than symptomatic to treat according to find the contradictions of individual shapes. The shapes and cases suffering frequently the hypersensitive large intestine syndrome are Gi-kwa and Sin-kwa, having a long nose, having a bruised spot on Triple warmer, man with inclined mouth, Taeeum type, man with congested fluids, man with colic symptoms. The hypersensitive large intestine syndrome in Oriental medicine is recognized of diarrhea, constipation, abdominal pain, abdominal distention and fullness caused by seven emotions. In Dongeuibogam it can be found out the similarity in depressive symptoms due to disorder of Gi, stagnation of Gi, dysphasia due to disorder of Gi, diarrhea due to disorder of Gi, fullness of due to Gi, diarrhea due to phlegm-retention, retention of undigested food, immoderate drinking, hypo-function of the spleen, or deficiency, abdominal pain from colic symptom, and difficulty in defecation and urination, internal injury, diarrhea due to weakness and fatigue. If the Jung, Gi, Sin, and Hyul composed the human body is broken harmony, the function of large intestinal transmission would be fallen, so similar symptoms like the hypersensitive large intestine syndrome are gotten. Especially Gi-kwa suffers diarrhea, constipation abdominal pain, and abdominal distention and fullness due to depressive symptoms from disorder of Seven emotions or Seven Gi. And Sin-kwa suffers from the hypersensitive large intestine syndrome due to emotional restlessness having an influence on rhythmic movement of abdomen. Examining between five viscera and six bowels and the hypersensitive large intestine syndrome, Liver cannot disperse well having influence on mutual relation of Liver-Large intestine, Heart reduces the function of defecation and urination not to control the seven emotions, Lung having exterior and interior relation with intestine has an influence on primordial energy and let the main symptoms occur, Spleen circulating the body fluid let the main symptoms occur due to malfunction of circulation, Kidney locating in lower part of the body has deep connection with intestine, so let the disorder. Urinary bladder is connected with intestine in moisture metabolism, Stomach is connected in receive and transmission, Small intestine is connected in absorption and excretion, from small intestine pain disturbing the abdominal movement, Samcho managing the catharsis of lower heater if declined its function causes the hypersensitive large intestine syndrome. The colic symptoms of Front private parts which disorder in lower abdomen give rise to abdominal pains, difficulty in defecation and urination due to Cold are similar to the hypersensitive large intestine syndrome. The treatments of applying the shapes of colic syndrome advocated by Master Park can be efficacious cure in clinic. Researching after the clinical cases of Master Park advocating Hyungsang medicine, we came to know that plenty of prescriptions of internal injury are applied and take good effects.