• 제목/요약/키워드: body stress

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PFA 라이닝 플러그 밸브 설계를 위한 밸브 본체의 응력 시뮬레이션 (A Study on the Stress Simulation for the Body Design of a PFA-lined Plug Valve)

  • 강신한
    • 한국산학기술학회논문지
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    • 제10권3호
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    • pp.500-506
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    • 2009
  • 본 논문은 주요 부위에 대한 정적음력 시뮬레이션을 통해 PFA 라이닝 플러그밸브 본체의 설계자를 지원하는 것을 주된 목표로 한다. CAD 작업을 통해 생성된 형상 모델을 스텝(step)파일로 변환하여 해석작업에 사용한다. 전문적인 해석경험이 없는 밸브 생산업체의 설계자가 형상 모델에 대한 인장, 굽힘, 비틀림 모멘트 등을 계산하는 과정을 이해함으로써 구조적 취약점을 사전에 파악하고, 제품에 반영하여 제품 신뢰도 및 설계효율 증대에 기여할 수 있는 기본적인 방안을 제시하고자 하였다.

일 대학 여대생의 골밀도, 체질량지수, 스트레스 및 건강증진 생활양식 (Bone Mineral Density, Body Mass Index, Stress, and Health Promotion Lifestyle of Female College Students)

  • 김춘미;김은만
    • 지역사회간호학회지
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    • 제21권3호
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    • pp.333-340
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    • 2010
  • Purpose: The purpose of this study was to examine the bone mineral density (BMD), body mass index (BMI), stress, and health promotion lifestyle of female college students and to assess relations among them. Methods: A total of 220 female college students were assessed through anthropometric measurements and bone mineral density test using quantitative ultrasound. In addition, the subjects were asked about stress and health promotion lifestyle with a self-rating questionnaire. Collected data were processed with the SPSS/WIN 12.0 program. Results: 1) Of the students, 67.8% had weight control experience. The percentage of the osteoporosis, osteopenia and normal groups were 2.8%, 53.5% and 43.8%, respectively, and the percentage of the underweight, normal and overweight groups according to BMI were 27.9%, 57.2% and 14.9%, respectively. 2) The levels of stress and health promotion lifestyle were 2.9 and 2.3, respectively. 3) There was a positive correlation between BMD and BMI (r=.196, p<.01). There was a negative correlation between stress and health promotion lifestyle (r=-.35, p<.01). 4) Weight control experience made negative effects on BMD and BMI. Conclusion: The findings of this study suggest the necessity of new health promotion programs to increase bone density of female college students. Stress management programs are also needed.

이완음악이 신체유연성과 스트레스에 미치는 영향 (The Effects of Relaxation Music on the Body Flexibility and Stress)

  • 이광재;김동훈
    • 대한물리치료과학회지
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    • 제22권2호
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    • pp.37-42
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    • 2015
  • Background : The purpose of this study is to identify how the relaxation music listening during exercise influences body flexibility and stress. Methods : Twenty healthy adults 20s and 30s who lack of body flexibility were recruited and each subjects performed exercise during the relaxation music listening or no listening. Bach, aria of linear G was used as the relaxation music. The experiment was conducted for 4 weeks. In this study, PASW ver 18.0 was utilized to perform non-parametric tests for comparisons. Result : The result with respect to the dependent variables are as follows: When non-parametric tests were conducted to compare body flexibility at the test of the right ear touch behind head by left hand and the stretching hands test between the two groups after exercise, they showed significant differences in statistical terms (p<.05). Conclusion : From the above results of the study it was found that the application of the relaxation music during the exercise is effective, it improved the body flexibility of the right ear touch behind head by left hand and the stretching hands more than the exercise without the relaxation music did. The outcome of the experiment may provide basic data for developing an effective way to increase body flexibility.

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하루 중 다른 시간대에 실시한 복합 트레이닝이 신체조성, 혈중지질, 스트레스 호르몬 및 영양소 섭취량에 미치는 영향 (The Effect of Combined Training at Different Times of Day on Body Composition, Plasma Lipids, Stress Hormones and Nutrient Intakes)

  • 이경영;김시영;전태원
    • 대한지역사회영양학회지
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    • 제11권1호
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    • pp.143-151
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    • 2006
  • Regular exercise training improves body composition, blood lipid profiles and exercise adaptation. This study was conducted to investigate the effect of exercise training at different times of day on body composition, blood lipids, stress hormones and nutrient intakes. Twenty four male graduate students carried out this experiment. The subjects were divided into three groups; morning exercise group, evening exercise group and control group. Two exercise groups performed running and muscular resistance training at mid intensity for 12 week periods. Body composition, blood lipid profiles, blood cortisol, ACTH and nutrient intakes were analyzed prior to, midway and after training. There were significant differences about interaction between different exercise times and training periods in plasma TG and HDL-C of the evening exercise training (p < 0.05). Also the evening exercise group was showed the decreasing of TC after training (p < 0.05). No significant differences about interaction between different exercise times and training periods were shown in body composition, stress hormones and nutrient intakes in the three groups. But evening exercise training decreased body fat ($\%$) and blood ACTH (p < 0.05). Also the increasing of carbohydrate intakes was shown by the evening exercise training (p < 0.05). In contrast, morning exercise group indicated a decrease of body fat ($\%$) after 6 week training (p < 0.05), but this effect was not maintained after 12 weeks of training. These results suggested that regular evening exercise is more effect than morning exercise from the viewpoint of improving body composition, blood lipids, nutrient intakes and exercise adaptation.

원전 역지 밸브/배관 맞대기 용접부와 밸브 몸체의 취성 파괴에 미치는 잔류응력 및 Charpy V-노치 충격에너지의 영향 고찰 (Investigation on Effects of Residual Stresses and Charpy V-Notch Impact Energy on Brittle Fractures of the Butt Weld between Close Check Valve and Piping, and of the Valve Body in Nuclear Power Plants)

  • 김종성;김현수
    • 한국압력기기공학회 논문집
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    • 제11권1호
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    • pp.69-73
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    • 2015
  • The study investigated effects of residual stresses and Charpy impact energy on brittle fractures of the butt weld between the valve and the piping, and of the valve body in nuclear power plants via a linear elastic fracture mechanics approach in the ASME B&PV Code, Sec.XI and finite element analysis. Weld residual stress in a butt weld between close check valve and piping, and residual stress in the valve due to casting process were assumed to be proportional to yield strength of base metal. Operating stresses in the butt weld and the valve body were calculated using approximate engineering formulae and finite element analysis, respectively. Applied stress intensity factors were calculated by assuming postulated cracks with specific sizes and then by substituting the residual stresses and the operating stresses into engineering formulae presented in the ASME B&PV Code, Sec.III. Plane strain fracture toughness was derived by using a correlation between Charpy V-notch impact energy and fracture toughness. Structural integrity of the weld and the body against brittle fracture was assessed by using the applied stress intensity factors, plane strain fracture toughness and the linear elastic fracture mechanics approach. As a result, it was identified that the structural integrity was maintained with decreasing the residual stress levels and increasing the Charpy V-notch impact energy.

한국여성의 자아존중감과 비만스트레스와의 융복합적 관계에 관한 연구 (Convergence Relationship between Self-Esteem and Obesity Stress among Women in Korea)

  • 박은희;박해령
    • 디지털융복합연구
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    • 제13권9호
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    • pp.479-487
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    • 2015
  • 본 연구는 20대 여성의 외모만족도, 외모지향성, 외모평가 및 자아존중감을 파악하고 각 요인들이 비만스트레스에 미치는 영향을 알아보고자 시행되었다. 분석결과 20대 여성은 실제 BMI(Body Mass Index)보다 주관적 체형을 더 크게 인식하고 있었다. 대상자의 제 변수간의 상관관계를 살펴본 결과, 외모지향성(r=.386, p=<.001), 자아존중감(r=.324, p=<.001)으로 정적상관성을, 외모평가(r=-453, p=<.001), 외모만족도(r=-.560, p=<.001)는 부적상관성을 보였다. 위계적 회귀방법으로 비만스트레스에 영향을 미치는 요인을 분석한 결과, 1단계 모형에서 외모만족도 31.3%, 2단계 모형에서 외모지향성, 외모평가, 외모만족도가 45.3%, 3단계 모형에서 주관적 체형, BMI 및 제 변수가 54.7%를 설명하였다. 분석결과를 토대로 20대 여성에게 실제 정상BMI를 가진 체형이 가장 이상적인 체형임을 인식하는 교육과 삶의 지표를 외형보다 내면에 둘 수 있도록 다양한 프로그램을 마련하는 것이 20대 여성의 비만스트레스를 다소나마 줄여 줄 수 있을 것으로 사료된다.

분만 중 전신마사지가 초산부의 분만진통과 분만스트레스 반응에 미치는 효과 (Effects of Full Body Massage on Labor Pain and Delivery Stress Reaction for Primipara during Labor)

  • 이군자;장춘자;조현숙
    • 여성건강간호학회지
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    • 제9권3호
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    • pp.224-234
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    • 2003
  • Purpose: This study was to test the effects of a full body massage on labor pain and delivery stress reaction for primipara during labor. Method: This study employed a quasi- experimental method(nonequivalent control group, pre-post test design). The subjects of this study were 57 primipara hospitalized at the U OB & GYN hospital in Inchon from November 1. 2001 to July 31, 2002. 28 women were assigned to the experimental group and 29 to the control group. The experimental group was given 20 minutes full body massage for each of three delivery phases. The control group was given conventional delivery care. The levels of labor pain were measured by the Visual Analogue Scale and the expression scores of the labor pain and the levels of delivery stress reaction were measured by pulse rate, respiration rate, and blood pressure, and State-Anxiety Scale. Data were analyzed using the repeated measures analysis of covariance(ANCOVA), t-test, $X^2$- test, simple ANCOVA with SPSS program. Result: There was no interaction effect between time and group(F=.370, p=.693), but significant time effects were found for subjective labor pain(F=3.840, p=.028). There was no interaction effect between time and group(F=.112, p=.894), but significant group effects were found for objective labor pain(F=12.299, p=.001). There was no interaction effect between time and group for PR(F=.172, p=.843), RR(F=.626, p=.539), SBP(F=.089, p=.915), DBP(F=.748, p=.479), but significant group effects were found for SBP(F=7.547, p=.008). The level of status anxiety of the experimental group was significantly lower than the control group(F=11.787, p=.001). Conclusion: This study showed that the full body massage has partially positive effect on labor pain and delivery stress reaction. Therefore this study suggested that the full body massage might be used clinically to help primipara during labor.

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2차원 선형 탄성 이방성 재료에서 $J_k$-적분을 이용한 응력확대계수 계산 (Calculation of Stress Intensity Factor in 2-D Using $J_k$-Integral for a Rectilinear Elastic Anisotropic Body)

  • 안득만;최창연
    • 한국정밀공학회지
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    • 제18권7호
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    • pp.134-142
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    • 2001
  • The integrals $J_k$(k=1,2) in the rectilinear anisotropis body in 2-D were determined using Lekhnitskii formalism. The relationship between $J_k$ and stress intensity factors are implified by the important equation between elastic compliance. The numerical evaluation of stress intensity factor for the single edge crack in mixed mode is determined by superposing known exact solutions.

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Salivary IgA and cortisol assessment, conductance measurement, three methods to evaluate the relaxing effect of cosmetic products

  • Buche, P.;Sirvent, A.;Girard, F.
    • 대한화장품학회:학술대회논문집
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    • 대한화장품학회 2003년도 IFSCC Conference Proceeding Book II
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    • pp.456-457
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    • 2003
  • The use of relaxing cosmetic products is more and more widespread on the self care market, since stress is considered as a major cause of discomfort in modem life. Cortisol, the stress hormone, helps the human body to regulate itself by acting on carbonhydrate, proteins and fat metabolisms. IgA are immune molecules involved in the stress response of the human body. The less the human body is stressed, the more the salivary IgA rate increases. Salivary cortisol and IgA have the advantage of being easily assessed with non invasive methods. Finally, conductance is the measurement of the modification in the electrical resistance of the skin. By this means, the measurement of the conductance enable the assessment of somebody's stress.(omitted)

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음향진동장치에 의한 인체의 스트레스 저감 효과 (The Effect of Stress Reduction of Human Body by the Vibroacoustic Equipment)

  • 문덕홍;김영완
    • 동력기계공학회지
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    • 제11권2호
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    • pp.32-37
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    • 2007
  • The present study describes the effects of music and vibroacoustic stimuli to the relaxation of human body. We have carried out the experiment on 6 human subjects of which are composed 3 men and 3 women. We have investigated the electroencephalogram(EEG) of all subjects before and after the stimuli of which are made a strong noise or the meditatiom music and the acoustic vibration. The vibroacoustic device has transmitted meditation music as vibration between 20Hz and 250Hz to the body. From the experimental results, we made sure the effects that the meditation music and vibroacoustic stimuli influenced the stress reduction of human body for good as alpha wave was increased continuously during the good stimuli and after that.

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