• Title/Summary/Keyword: Total Stress Analysis

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Seismic Qualification Analysis of a Vertical-Axis Wind Turbine (소형 수직축 풍력발전기의 내진검증 해석)

  • Choi, Young-Hyu;Hong, Min-Gi
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.15 no.3
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    • pp.21-27
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    • 2016
  • The static and dynamic structural integrity qualification was performed through the seismic analysis of a small-size Savonius-type vertical wind turbine at dead weight plus wind load and seismic loads. The ANSYS finite element program was used to develop the FEM model of the wind turbine and to accomplish static, modal, and dynamic frequency response analyses. The stress of the wind turbine structure for each wind load and dead weight was calculated and combined by taking the square root of the sum of the squares (SRSS) to obtain static stresses. Seismic response spectrum analysis was also carried out in the horizontal (X and Y) and vertical (Z) directions to determine the response stress distribution for the required response spectrum (RRS) at safe-shutdown earthquake with a 5% damping (SSE-5%) condition. The stress resulting from the seismic analysis in each of the three directions was combined with the SRSS to yield dynamic stresses. These static and dynamic stresses were summed by using the same SRSS. Finally, this total stress was compared with the allowable stress design, which was calculated based on the requirements of the KBC 2009, KS C IEC 61400-1, and KS C IEC 61400-2 codes.

Analysis on Stress and Dietary Attitudes of Male Employees (직장인 남성의 스트레스와 식생활 태도에 관한 분석)

  • Lee, Mi-Ae;Lee, Eun-Ju;Soh, Hye-Kyung;Choi, Bong-Soon
    • Korean Journal of Community Nutrition
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    • v.16 no.3
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    • pp.337-352
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    • 2011
  • This study was conducted to vitalize life through analysis on lifestyles, stress and dietary habits of male employees. For this study, questionnaire survey and physical measurements to examine BMI and waist circumference were performed with male employees in four companies located in Gyeongnam. Total 350 copies of the questionnaire were distributed and 327 ones were finally analyzed. The results of analysis on dietary liferelated problems and stress were as follows. First, according to BMI, 56.9% were overweight and waist circumference recorded less than 90 cm in 90.5%. For lifestyles, 54.1%, 79.2%, 60.9% and 52.3% smoked, drank alcohol, didn't exercise and didn't sleep sufficiently. Second, for the correlation with job stress, the subjects graduating junior college or lower academic institution, production employees and sleeping insufficiently showed higher compared to the others. Analysis on the correlation with life stress found that conjugal relation stress was higher in alcohol-drinkers, the males not taking dietary supplements, those with a normal weight or more compared to underweight ones. Stress from relation with a child was higher aged 35~49 years than in those aged 20~34 years, and stress from economic life was higher aged less than 50 years, in those graduating junior colleges compared to those graduating colleges, in those sleeping insufficiently. Health life stress was found to be higher in those without religion compared to those with it such as Protestant Christianity and Catholicism, in alcohol drinkers and in those sleeping insufficiently and having a disease. Based on this, in order to improve the lifestyles and dietary habits and release stress effectively, practical nutrition education program should be carried out.

A Study on the Development of an Infertility Stress Scale (불임 스트레스 척도 개발에 관한 연구)

  • 김선행;박영주;장성옥
    • Journal of Korean Academy of Nursing
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    • v.25 no.1
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    • pp.141-155
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    • 1995
  • The objective of this study was to develop a scale to measure stress in infertile couples and to test its reliability and validity. Prior to item generation, a basic decision was made to conceptualize stress in infertile couples as including two dimensions and four subdimensions. The dimensions were, intrapersonal stress including cognitive and affective stress, and interpersonal stress including marital and social stress. Initially 95 items were generated from the inter-view data of 31 primary or secondary infertile women and from a literature review. These items were analyzed through the Index of Content Validity(CVI) and 69 items were selected which met 70% or more of the CVI. This preliminary Infertility Stress Scale were analyzed for reliability and construct validity. Item analysis and factor analysis were applied for construct validity. Forty items were selected through item analysis. This procedure was based on the inter-item correlation matrix, a corrected average inter-item correlation coefficient(.30~.70), a corrected item to total correlation coefficient (.03 or more) and information about the alpha estimate if this item was dropped from the scale. The result of the initial factor analysis including varimax rotation produced eight factors. Five items deleted because of factor complexity(indiscriminate factor loadings). The secondary factor analysis including varimax rotation produced seven factors that coincided with the conceptual framework posed for the scale developed. The seven factors were labeled as ‘meaning of children’,‘worthiness’,‘tenacious linking’,‘marital satisfaction’,‘sexual satisfaction’,‘familial adjustment’ and ‘social adjustment’. The alpha coefficient relating to internal consistency was .93 for reliability The results of this study suggest that the measurement derived from the Infertility Stress Scale is useful in assessing the stress of infertile couples.

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Variations of glucosinolates in kale leaves (Brassica oleracea var. acephala) treated with drought-stress in autumn and spring seasons (수분스트레스에 의한 케일 내 글루코시놀레이트 변화)

  • Jeong, Na-Rae;Chun, Jin-Hyuk;Park, Eun-Jae;Lim, Ye-Hoon;Kim, Sun-Ju
    • Korean Journal of Agricultural Science
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    • v.42 no.3
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    • pp.167-175
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    • 2015
  • The present study aimed to investigate the effects of drought stress on the accumulation of glucosinolates (GSLs) in the leaves of Kale cultivated in autumn and spring. HPLC analysis guided to identify seven GSLs including progoitrin, glucoraphanin, sinigrin, gluconapin, glucobrassicin, 4-methoxyglucobrassicin and neoglucobrasscin. Quantification of GSLs revealed that the contents of sigirin was the highest (45%) followed by the level of progoitrin (24%) in terms of total GSLs. The ranges of total GSL contents was 1.16 (84)-15.88 (89 DAS, ${\mu}mol/g$ dry wt. (DW)) in treatment plot and 1.23 (84)-7.05 (74 DAS, ${\mu}mol/g$ dry wt.) in control plot showed the enhancement in the contents of GSLs in treatment than in the control plot. The present results evidenced that the variation of total GSL contents were depending on the harvest period. In 105 DAS, comparatively no differences in the GSL contents on each sample in autumn season, whereas in spring season, although there was decrease in the GSLs tendency from 74 DAS to 84 DAS in both control and treatment plot, the GSL contents of treatment plot was dramatically increased in 89 DAS. In treatment plot, the GSL contents on 89 DAS (1.16) was 15 fold higher to 84 DAS ($15.88{\mu}mol/g$ DW). The variation in the contents of GSL in spring and autumn did not documented significant differences because of their differences in the growth time and cultivation conditions. In conclusion, the GSL contents in kale was likely to be affected by drought stress treatment. Scrutiny and further research for exact relation between drought stress and GSL contents in kale should be needed.

Proteome analysis of roots of sorghum under copper stress

  • Roy, Swapan Kumar;Cho, Seong-Woo;Kwon, Soo Jeong;Kamal, Abu Hena Mostafa;Lee, Dong-Gi;Sarker, Kabita;Lee, Moon-Soon;Xin, Zhanguo;Woo, Sun-Hee
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.130-130
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    • 2017
  • Sorghum bicolor is considered as copper-tolerant species. The present study was conducted to understand the copper tolerance mechanism in Sorghum seedling roots. Morphological and effects of Cu on other interacting ions were observed prominently in the roots when the plants were subjected to different concentrations (0, 50, and $100{\mu}M$) of $CuSO_4$. However, the morphological characteristics were reduced by Cu stress, and the most significant growth inhibition was observed in plants treated with the highest concentration of $Cu^{2+}$ ions ($100{\mu}M$). In the proteome analysis, high-throughput two-dimensional polyacrylamide gel electrophoresis coupled with MALDI-TOF-TOF mass spectrometry was performed to explore the molecular responses of Cu-induced sorghum seedling roots. In two-dimensional silver-stained gels, a total of 422 differentially expressed proteins (${\geq}1.5-fold$) were identified using Progenesis SameSpot software. A total of 21 protein spots (${\geq}1.5-fold$) from Cu-induced sorghum roots were analyzed by mass spectrometry. Of the 21 differentially expressed protein spots from Cu-induced sorghum roots, a total of 10 proteins were up-regulated, and 11 proteins were down-regulated. The abundance of the most identified protein species from the roots that function in stress response and metabolism was significantly enhanced, while protein species involved in transcription and regulation were severely reduced. The results obtained from the present study may provide insights into the tolerance mechanism of seedling roots in Sorghum.

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Association of Sleep Duration with Stress Status and Nutritional Quotient for Korean Adolescents (NQ-A) in High School Students in Chungbuk (충북지역 일부 고등학생의 수면시간과 스트레스 및 청소년 영양지수와의 관련성)

  • Bae, Yun-Jung;Kim, In Young;Kim, Ok Sun;Choi, Mi-Kyeong
    • Journal of the Korean Dietetic Association
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    • v.27 no.2
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    • pp.113-123
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    • 2021
  • This study aimed to examine the association between sleep duration, stress levels, and dietary behavior in adolescents. A survey was conducted on 453 students (227 male, 226 female) in high schools in the Chungbuk area. The participants were divided into groups based on daily sleep duration: group I (<5 hrs/d), group II (≥5 hrs/d and <6 hrs/d), group III (≥6 hrs/d and <7 hrs/d), and group IV (≥7 hrs/d). To measure the stress levels of participants, the survey had questions covering a variety of areas, including school life, family life, social relationships, and personal evaluation. To assess the dietary behaviors of participants, the survey included questions encompassing the Nutrition Quotient for Korean adolescents (NQ-A). Among female students, the sleep duration group IV had significantly lower total stress (P=0.022) and significantly lower stress in the personal evaluation area than the sleep duration group I (P=0.004). In the analysis of NQ-A, among female students, the sleep duration group IV showed significantly higher scores in balance (P=0.004), diversity (P=0.016), and total NQ-A score area (P=0.007) compared to other groups. There was a significant negative correlation between sleep duration and stress scores in total students (r=-0.24, P<0.001), while a significant positive correlation was seen between sleep duration and NQ-A scores in female students (r=0.16, P<0.05). To sum up, the longer the sleep duration, the lower the degree of stress, and the quality of meals which can be said to be a significant finding for high school students.

Structural Analysis of Hydraulic Valve Meter (밸브 수압측정기의 구조해석)

  • Lee, Jong-Sun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.4
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    • pp.1447-1452
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    • 2012
  • Existing hydraulic valve meter used in industrial fields precise pressure measurement gives inconvenience in precise measurement due to manually regulated pressures. In order to improve this inconvenience, the hydraulic valve meter was designed by using automatic design program CATIA and structural analysis of the designed hydraulic valve meter was conducted and internal water leaking, stress, strain and total deformation were obtained by applying three dimensional finite element code ANSYS. These results will be provided to develop new concepts of hydraulic valve meters as fundamental data.

Study of Lyric Analysis Using a Mind-map on Parenting Stress in Mothers of Children with Disability (마인드맵을 활용한 노래가사분석(Lyric Analysis) 활동을 통한 장애아동 어머니의 양육스트레스 감소에 관한 연구)

  • Kim, Jin
    • Journal of Music and Human Behavior
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    • v.7 no.2
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    • pp.23-45
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    • 2010
  • The purpose of this study is to determine the effects of lyric analysis using the mind-map technique on parenting stress of mothers with disabled children. Six mothers performed psychological tests to confirm the level of parenting stress. Participants attended a total of fourteen lyric-analysis using mind-map programs and the Questionnaire on Resource and Stress (QRS) was administered before the first session and after the last session. Results showed a significant difference (p<.05) in perceived parenting stress. Also positive changes were observed from video analysis of each session. Overall, this study suggests that the lyric analysis based on the application of mind-map may have the positive influence on the parenting stress of mothers raising disabled children.

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Stress Analysis near a Circular Hole in a Flat Plate Attached to a Cyinder -The Key Subject is the Change of the Cylindrical Shell-Length- (圓筒이 붙은 平板의 應力解析)

  • 정인승;이대희;윤갑영
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.10 no.5
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    • pp.770-778
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    • 1986
  • This paper is studied on the Junctiion of the large tank and the cylinderical outlet such as a pressure vessel attached a pipe or nozzle theoretically. It is assumed that the diameter of tank is much larger than that of the nozzle, so it can be approximated that nozzle is attached to plate. The analysis procedure can be viewed as the solution of interdependent subproblems: (a) the stress analysis of the cylinderical shell(nozzle), (b) the plane-stress analysis of the plate membrane problem, and (c) the analysis of the transverse bending deformation in the plate. On the procedure of (a), the Flugge formula are used, and the variables are the length and the ratio of the thickness to the radius of cylinderical shell. The solutions of thess problems are interrelated in the total solution through continuity and equilibrium conditions at the interface of middle planes of the plate and cylinderical shell.

Finite element stress analysis on supporting bone by tripodal placement of implant fixture (유한요소법을 이용한 임플란트 고정체의 삼각배열에 따른 지지골의 응력 분석)

  • Son, Sung-Sik;Lee, Myung-Kon
    • Journal of Technologic Dentistry
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    • v.31 no.1
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    • pp.7-15
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    • 2009
  • Purpose: This study was to propose the clear understanding for stress distribution of supporting bone by use of staggered buccal offset tripodal placement of fixtures of posterior 3 crown implant partial dentures. We realized posterior 3 crown implant fixed partial dentures through finite element modeling and analysed stress effect of implant arrangement location to supporting bone under external load using finite element method. Method: To understand stress distribution of 3 crown implant fixed partial dentures which have 2 different arrangement by finite element analysis. In each model, for loading condition, we applied $45^{\circ}$ oblique load to occlusal surface of crown and applied 100 N for 3 crown individually(total 300 N) for imitating possible oral loading condition. at this time, we calculated Von Mises stress distribution in supporting bone through finite element method. Result: When apply $45^{\circ}$ oblique load to in-line arrangement model, maximum stress result for 100 N for each 3 crown 47.566MPa. In tripodal placement, result for 1mm buccal offset tripodal placement implant model was maximum distributed load 51.418MPa, so result was higher than in-line arrangement model. Conclusion: In stress distribution result by placement of implant fixture, the most effective structure was in-line arrangement. The tripodal placement does not effective for stress distribution, gap cause more damage to supporting bone.

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