• 제목/요약/키워드: Study Stress

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두꺼운 연강판(軟鋼板) 필렛 용접(熔接)이음부의 잔류응력분포(殘留應力分布)에 대한 연구(硏究) (A Study on the Distribution of Residual Stress in Fillet Welds for Thick Mild Steel Plate)

  • 엄동석;강성원
    • 대한조선학회지
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    • 제20권4호
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    • pp.17-24
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    • 1983
  • In this study, it was investigated the distribution of residual stress in the direction of loading between the root and toe the load fillet welds for thick steel plate. Residual stress distributions are measured by sectioning method which is one of stress-relaxation technique in welded joint, and analyzed by two dimensional finite element method on thermo-elasto-plastic theory under plane stress condition. These are compared the results of F.E.M analysis with the experimental result by stress-relaxation techniques. As a results, the following conclusion were obtained. (1) In the no penetration fillet welded joint specimen using mild steel plate with 25mm in thickness, the residual stress of loading direction near the root was about $10kg/mm^2$ tensile. (2) The tensile residual stress has been observed in fillet region of the fillet joint by F.E.M. analysis method. (3) The range of compressive residual stress distribution from the root was largest in the case of 5mm root penetration.

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향기요법이 고등학생의 스트레스와 스트레스 반응에 미치는 효과 (The Effects of Aromatherapy on Stress and Stress Responses in Adolescents)

  • 서지영
    • 대한간호학회지
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    • 제39권3호
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    • pp.357-365
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    • 2009
  • Purpose: This study was done to examine the effects of aromatherapy on stress and stress responses in adolescents. Methods: A two-group cross-over design was used for this study. The experimental treatment was aroma essential oil inhalation and the placebo treatment was carrier oil inhalation using a necklace. The sample included 36 female high school students. Fisher's exact test, t-test, and paired t-test using SPSS/WIN program were used to analyze the data. Results: Stress levels were significantly lower when the students received the aroma treatment compared to when they received the placebo treatment. The stress responses except salivary IgA levels were significantly lower when the students received the aroma treatment. Conclusion: Aroma inhalation could be a very effective stress management method for high school students. Therefore, it is recommended that this program be used in clinical practice as an effective nursing intervention for high school students.

지하절 종사자의 작업능력과 직무스트레스 평가에 관한 연구 (The Evaluation of Work Ability and Job Stress for Subway Worker)

  • 김유창;김종곤
    • 한국안전학회지
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    • 제23권4호
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    • pp.85-89
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    • 2008
  • Work ability and job stress have become the important issues in Korean workplace recently. This study researched work ability and job stress and also analyzed correlation with work ability and job stress using the Work Ability Index and the Karasek's Job Content Questionnaire against 742 subway workers. As the results, Work ability in subway workers was good in general. The relation between job stress and job type showed statistical significance (p<0.05). The relation between job stress and diseases showed statistical significance in musculoskeletal disorders(p<0.05), heart disease, and gastrointestinal disease. The correlations between work ability and job stress showed statistical significance in job demand and social support(p<0.05). The result of this study could be useful to manage the work ability of aging worker and the job stress in industry.

304 스테인레스강 용접부 잔류응력에 미치는 예열 효과의 유한요속 해석 (Finite Element Analysis of Effect of Preheating on the Residual Stress in 304 Stainless Steel Weldment)

  • 장경복;김하근;강성수
    • Journal of Welding and Joining
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    • 제16권5호
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    • pp.67-75
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    • 1998
  • This study aimed at he experimental and finite element analytic investigation of the effect of preheating on he residual stress of weldment. In this study, an autogenous arc welding was used on type 304 stainless steel and MARC as F.E.M. common code was utilized in analysis The analyses include transient and moving heat source and thermal properties as function of temperature. During welding, the thermal cycles of four locations in the weldment were recorded to investigate of the behavior of thermal stress and residual stress. The experimental and analytic results had good coincidence and show that there are two factors influencing the formation of welding residual stress in preheat process. One is the elevation of welding equilibrium temperature and the other is the increase of amount of heat input. The former decrease welding residual stress and the latter increase welding residual stress. Therefore, the cumulative effects result in the welding residual stress not being improved significantly with preheating in 304 stainless steel.

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벽체형 매스콘크리트구조물의 온도 및 온도응력측정에 관한 실험적 연구 (An Experimental Study on the Measurement of Temperature and Thermal Stress of Wall Type Mass Concrete Structure)

  • 강석화;이용호;정한중;박칠림
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1995년도 가을 학술발표회 논문집
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    • pp.173-177
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    • 1995
  • Thermal cracks ard occured when thermal stress due to the hydration of cement exceeds the tensile strength of concrete. Since cracking causes poor durability of concrete, the effect of thermal cracking should be included for the desing and construction of massive concrete structures. In this study, an experiments are performed for the investigation of time dependent temperature and thermal stress of massive concrete structure at early ages. In order to measure temperatures and thermal stresses, concrete stress meter, embedded strain meter, non-stress meter, and thermocouples are used. Based on the analyses of measured thermal stress data, measured values by concrete stress meter are more reliable than those by embedded strain meter and non-stress meter, And measured values by concrete stress meter are compared with the calculated values by FEM program developed by DICT (DWTS2D). Calculated values by DWTS2D show good agreement with measured values.

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간호대학생과 일반 여자대학생의 건강행위, 스트레스 및 대처유형 비교 (Comparison of Health Behavior, Stress and Stress Coping Type between Undergraduate Nursing Students and Female Students in Other Majors)

  • 김현
    • 동서간호학연구지
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    • 제21권1호
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    • pp.28-35
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    • 2015
  • Purpose: The purpose of this study was to compare the stress and stress coping type between nursing students and female students in other majors. Methods: This study adopted a descriptive comparative design. Data were collected by interviews with 184 undergraduate nursing students at N university and 194 female students in other majors at S university in C city from May 15 to 30, 2014. Data were analyzed by descriptive statistics, t-test, Chi-square, and Pearson's correlation with SPSS/WIN 22.0 program. Results: There was a significant difference on health behavior between nursing students and female students in other majors. The nursing students had a higher stress score than female students in other majors. There was a significant correlation between some health behavior and stress coping type. Conclusion: Based on the results, health promoting programs and research should be developed considering stress and coping type of nursing students.

통사적 모호성과 음운 구조 (Syntactic ambiguity and phonological structure)

  • 임운
    • 대한음성학회지:말소리
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    • 제42호
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    • pp.57-69
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    • 2001
  • Syntactic ambiguity can be understood by context usually, especially in reading and writing. Because phonological structure including stress, intonation and phonological phenomena can be pronounced differently according to different syntactic structures, syntactic ambiguity can be solved by phonological structure in listening and speaking. The objectives of this study was to survey how Korean English teachers apply phonological structures in order to solve syntactic ambiguity. The results of this study is as follows: First, Korean English leachers applied Compound Stress Rules well, when the second word was not branched. But they did not apply Compound Stress Rules well, when the second word was branched. Second, several Korean English teachers did not apply Nuclear Stress Rules well. They usually put the strongest stress on the first word. Third Korean English teachers did not differentiate appropriate applying situation of palatalization. They applied palatalization at both the single and the separated Phonological Phrase. Fourth, Korean English teachers did not apply stress shifting when stress crash happened. Because they did not apply stress shifting, they put the strongest stress on inappropriate syllable.

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일부 지방 간호학과 학생의 스트레스 측정과 분석 (A study on the stress of nursing students in a university)

  • 강남미
    • 한국간호교육학회지
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    • 제3권
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    • pp.7-25
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    • 1997
  • Using the self-evaluation test proposed by D. Girdano, et al., the psycological, and biological causes and personality factors of the stress of the nursing students of K university in local county are measured and analyzed. As fundamental data to overcome these kinds of stress, the overall stress profiles are proposed. The results of this study are ; 1) The freshman group is very susceptible to the stress due to the behavior type and anxiety-reactive personality. 2) The sophomore group is very susceptible to the stress due to frustration, the behavior type and anxiety-reactive personality. 3) Two groups are not susceptible to the stress due to diet and noise. Since the stress is the multi-dimensional phenomena, it is necessary to reduce these stress that the life style of each Individual students be changed and the curriculm and the teaching methodology in nursing school be developed.

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유아 스트레스의 관련 변인 연구 (Relevant Variables of Young Children's Stress)

  • 박소영;문혁준
    • 대한가정학회지
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    • 제42권12호
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    • pp.1-14
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    • 2004
  • The purpose of this study was to identify how characteristics of young children (sex, age, birth order, temperament), parents (education level, employed or unemployed mother, mother's parenting behavior), and family (income) relate to young children's stress levels and to examine the relative effects of these variables on young children's stress. The subjects for this study were 287 young children, aged from 3 to 5 years old, selected from kindergartens and day-care centers in Busan. Data were analyzed with t-test, ANOVA, correlation, and multiple regression. The results were as follows. (1) Young children's stress was correlated with young children's sex, age, birth order and temperament. (2) Young children's stress was correlated with parenting behaviors. (3) Young children's stress was not correlated with income. (4) Children's emotionality and maternal overprotective behavior were the most significant variables affecting the stress experienced by boys and girls, respectively. (5) Maternal overprotective behavior variable affected both sibling and only children's stress.

강철도교의 응력발생모형을 이용한 피로수명 추정에 관한 연구 (A Study on the Estimation of the Fatigue Life Using the Stress Generated Models in the Steel Railroad Bridges)

  • 용환선;김석태;이승수
    • 한국강구조학회 논문집
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    • 제8권4호통권29호
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    • pp.19-29
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    • 1996
  • In this paper, it is presumed that the stress time history was generated by simulation method and investigated compatibility in regard to the reappearance of stress time history. In this procedure, the identified frequency distribution of stress range of the steel railroad bridge varies with the rational values of cut off point and bar width. Thus, we show variable aspect of the equivalent stress range results from change of cut off point and bar width. In addition, we analyze the variable of RMC and RMS model due to the cut off point and bar width of the measured stress history which influencs the prediction of fatigue life in the steel railroad bridge. The simulated stress time history is carried out by the superposition method incorporating the vertical load with rotation moment obtained from the Hermition interpolation function, and compared with developing stress results from measured maxi mum stress. Through this study, we can estimate the remaining fatigue life from a safety point of view and comparative accuracy.

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