• Title/Summary/Keyword: stress check

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Stress Analysis and Sizing for a Glass/Epoxy Composite Wind Turbine Blade (풍력발전기용 대형 복합재 블레이드에 대한 구조 해석 및 사이징에 관한 연구)

  • 이충훈;박진무;홍순곤;박지상;김태욱
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2002.10a
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    • pp.5-9
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    • 2002
  • This paper presents a method and procedure for stress analysis and sizing in development of structures of a large composite wind turbine blade. Structural requirement of IEC standard was reviewed to set up appropriate analysis method and procedure. Several structural layouts were examined in a viewpoint of a large scale wind turbine blade. For the critical load cases, stress analysis were performed using finite element method. Stacking sequence and thickness of a laminate for each part and location were determined considering stress levels and producibility. Nonlinear geometric analysis was performed to check stability problem due to local buckling of a skin structures.

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Stress Analysis on a Structure of Solar Tracker Subjected to Wind Load (풍하중을 받는 태양광 추적 구조물의 응력해석)

  • Kim, Yong-Woo;Kim, Won-Bong
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.5
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    • pp.747-754
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    • 2012
  • A solar power generator is usually installed outdoors and it is exposed to extreme environments such as snow weight and wind loading. The solar tracker structure should be designed to have sufficient stiffness and strength against such loads. In this paper, simulations are performed by varying the parameters such as wind directions, wind speeds and the pose of the solar panel to evaluate the effects of extreme wind on solar tracker. As the effects of wind load, maximum displacement and maximum equivalent stress in the solar tracker are calculated. Finite element stress analysis is carried out by using the pressure distribution that is obtained by prior wind load analysis due to the flow around the solar tracker. The stress analysis of solar tracker to check and/or improve structural robustness provides some useful instructions for structural design or revision of solar tracker.

Evaluation of Ultimate Strength Design Equations for Stress Calculation of Unbonded Tendons (비부착 긴장재의 응력산정을 위한 극한강도 설계식의 평가)

  • 임재형;문정호;이리형
    • Journal of the Korea Concrete Institute
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    • v.11 no.3
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    • pp.113-122
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    • 1999
  • The present study is to investigate the possibility of overestimation or underestimation when the ACI Code equations are used to evaluate the unbonded tendon stress. An experimental program was planned with 6 beams which divided into two groups. Each group consisted of 3 beams to check the possibility of overestimation or underestimation of unbonded tendon stress. The experimental results were also compared with various design equations including the one proposed by Moon and Lim. It was proven that the ACI Code equations may overestimate or underestimate the unbonded tendon stress in certain cases.

Process Design of Automobile Steering Yoke with burring (버링 가공을 이용한 자동차 요크 제품의 가공 공정 설계)

  • 김병민
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2000.04a
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    • pp.151-154
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    • 2000
  • The yoke is used for joining the mechanical element of a spider and shaft in the steering system of automobiles. Conventional yoke forming processes are too complicated such as 4 stages bending and forming. The weight of yoke is also heavy than other components. New process is necessary to reduce the product weight to improve the strength and to reduce the costs. Process designed to reduce number of forming stages and to reduce its weight. To check the strength the stress analyses are performed between conventional yoke and developed one.

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A Study of Depression, Anxiety, Stress Response and Self-care by Gender in Diabetic Patients (당뇨병 환자의 성별 우울, 불안, 스트레스 반응과 자가관리의 관계연구)

  • Song, Min-Sun;Cho, Young-Im
    • The Korean Journal of Rehabilitation Nursing
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    • v.9 no.2
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    • pp.145-152
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    • 2006
  • Purpose: The purpose of this study was to investigate the depression, anxiety, stress response and self-care, to analyze the correlation among depression, anxiety, stress response and self-care by gender, and to determine factors associated with self-care in diabetic patients. Method: The subjects of this study were 103 participants with diabetes mellitus. Data were analyzed by chi-square test, t-test, Pearson correlation coefficient and multiple regression analysis by using SAS program. Result: Items for self-care evaluation by gender were significant differences in hospital visit, hypoglycemia preparation, proper hygiene, taking a rest, foot injury check, drinking, and smoking. The female patients are more likely to have higher self-care score than the male patients. However, there were no differences in depression, anxiety and stress response by gender. In male patients, there were positive correlations between the degree of depression and stress response, the degree of anxiety and stress response. In female patients, there were positive correlations between the degree of depression and stress response, the degree of anxiety and stress response. In multiple regression analysis, gender and experienced admission is associated with self-care. Conclusion: We should consider integrated approaches for psychological problems in the management of diabetic patients.

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A Study on the Job Stress of the Hotel Employees (호텔종사자의 직장 내에서의 스트레스에 관한 연구)

  • 이선호
    • Culinary science and hospitality research
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    • v.7 no.2
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    • pp.195-215
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    • 2001
  • This study is of an analysis of the kinds of influences on the subordinate variables through the adjusting variables by the independent variables which serve as the perception factor of job stress. also This study, with taking the workers for the hotel employees who are in the room, food & beverage and cook, was carried out so as to analyze deeply and throughly the stress of work they experience in doing their job and the tension incited from this stress and the strategy used for meeting this stress to grope for raising plan for the degree of satisfaction with their job of the workers for the hotel. In order for, this study ran paralled with literature study and research study, taking 615 workers who are now working in hotel. Job stress is easily negligible in hotel business not only because it is hard to identify and measure its concrete entity on account of its intangible characteristic but also because it is impossible to check physically the relationship with each direct behavior. If job stress continue, however, it can cause neglect of duty, change of occupation, deterioration of service quality and eventually aggravate the cost of a hotel business and decrease the hotel sales. Consequently, it is highly necessary to increase job satisfaction by identifying systematically and eliminating the stress factor of hotel employees in order to accomplish particularly experience unique job stress in the course of contact since they should provide the customer with their services.

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The Effect of Parenting Stress on Preschool Children's Problematic Behavior in Multicultural Families (다문화가정 어머니의 양육스트레스가 유아의 문제행동에 미치는 영향)

  • Yin, Chu-Yuan;Jang, Young-Ae
    • The Korean Journal of Community Living Science
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    • v.23 no.1
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    • pp.5-16
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    • 2012
  • The purpose of this study was to examine the impact of parenting stress on children's problematic behavior in multicultural families. The subjects were 143 mothers who are caring for their 3-6 year old children in multicultural families. Data was collected using a parenting stress index and a child behavior check list. The data were statistically analyzed using a t-test, a one-way ANOVA(Scheff'e test), a correlation analysis and multiple regression analysis. The study showed that there were no significant differences in parenting stress according to the socio-demographic variables. However, there were some significant differences in children's problematic behavior according to the mother's education. Correlation analysis indicated that the mother's parenting stress and children's problematic behavior in multicultural families had significant positive correlations in all sub-variables. It was also found that the mother's education, the mother's stress caused by a difficult child, the mother's stress caused by dysfuntional interactions between parents and children and educational distress, were all significant predictors of the preschool children's problematic behavior in multicultural families.

The Relationship between Work Stress and Musculoskeletal Disorders of Hair Designers (미용업종사자들의 근골격계관련작업이 직무스트레스에 미치는 영향)

  • Oh, Sun-Young;Nam, Chul-Hyun
    • Journal of Society of Preventive Korean Medicine
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    • v.14 no.3
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    • pp.51-61
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    • 2010
  • This study aimed to evaluate musculoskeletal workload associated with the work of hair designers, to identify the factors associated with work-related stress, depression and musculoskeletal symptoms in Hair Designers, and to check the painful areas based on patients who complained of musculoskeletal symptoms. The data were collected from 279 hair designers in Daegu metropolitan city from February 1 to August 31 of 2009. A summary of the results was as follows : According to work-related stress in study subjects, the degree of stress load was relatively higher in association with the working demand, the relational conflicts and the organizational culture, but the degree of stress was found to be relatively lower in association with the physical environment, work-related autonomy, an insufficient compensation and an occupational instability. People engaged for beauty business have gotten lots of stress because of the endless needs from customers, the pressure of the learning new skills and the uncomfortable working environment. These are able to cause the musculoskeletal disorder. Under this circumstance, small fries do not have any prevention managements for improving the musculoskeletal diseases and they are not afforded to have regular checkup. When teaching the people related with beauty business, it is necessary to provide accurate information like correct carriage to reduce musculoskeletal disorder stress.

Reliability of a Newly Developed Tool to Assess and Classify Work-related Stress (TAWS-16) for Indian Workforce

  • Gautham Melur Sukumar;Runalika Roy;Mariamma Philip;Gururaj Gopalkrishna
    • Journal of Preventive Medicine and Public Health
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    • v.56 no.5
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    • pp.407-412
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    • 2023
  • Objectives: Work stress is associated with non-communicable diseases, increased healthcare costs, and decreased work productivity among employees in the information technology sector. There is a need for regular work-stress screening among employees using valid and reliable tools. The Tool to Assess and Classify Work Stress (TAWS-16) was developed to overcome limitations in existing stress assessment tools in India. This study aimed to test the reliability of TAWS-16 in a sample of managerial-supervisory employees. Methods: This observational reliability study included data from 62 employees. Test-retest and inter-method reliability were investigated using a TAWS-16 web application and interview by telephone, respectively. Kappa values and intra-class correlation coefficients were calculated. Internal consistency was assessed through Cronbach's alpha. Results: For both test-retest and inter-method reliability, the agreement for both work-related factors and symptoms suggestive of work stress exceeded 80%, and all kappa values were 0.40 or higher. Cronbach's alpha for test-retest and inter-method reliability was 0.983 and 0.941, respectively. Conclusions: TAWS-16 demonstrated acceptable reliability. It measured stressors, coping abilities, and psychosomatic symptoms associated with work stress. We recommend using TAWS-16 to holistically identify work stress among employees during periodical health check-ups in India.

Variation in root system developmental responses of irrigated and rainfed philippine rice varieties to water stressed environments

  • Cabral, Maria Corazon J.;Niones, Jonathan M.;Suralta, Roel R.;Yamauchi, Akira
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.230-230
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    • 2017
  • About 200 rice varieties for irrigated and rainfed lowland ecosystems were released in the Philippines, which were bred for improving yield under favorable conditions. Root plasticity plays key roles in maintaining crop productivity under abiotic stressed conditions. We hypothesized that some of these varieties possess root plasticity traits in response to water stressed conditions. This study aimed to evaluate the root system development and dry matter production of 14 randomly selected rice varieties (6 irrigated lowland and 9 rainfed varieties) under progressive drought (PDR) and soil moisture fluctuations (SMF) stress conditions. Two experiments were done in rootbox and line source sprinkler systems (LSS). Each of the varieties was subjected to well-watered (WW), PDR and SMF conditions during vegetative stage in rootbox system while the same genotypes were subjected to different intensities of drought stress under LSS. Under rootbox system, PDR and SMF significantly reduced shoot dry matter production in all varieties relative to their WW controls. Among varieties, NSIC Rc238 (irrigated lowland) showed the least reduction in shoot dry weight (SDW) in both PDR (by 11.8%) and SMF (by 26.9%) conditions. Less reductions in SDW of NSICRc238 were partially attributed to the promotion of L-type lateral roots, thus increasing total lateral root length by 24.2% and 30.7% under PDR and SMF, respectively. In LSS, SDW of NSIC Rc238 under mild drought stress (16-21% soil moisture content (SMC) had 31.8% reduction relative to its WW control (${\geq}22%SMC$) and had lower sensitivity drought index. Compared with the IR64 susceptible check and NSIC Rc9 tolerant check, NSIC Rc238 had higher SDW by 90.8% and 38.6%, respectively. Furthermore, no rainfed lowland varieties included in the experiment performed well under different water stress treatments. The results implied that some other irrigated lowland rice varieties may also possess drought dehydration avoidance root plasticity traits under water-stressed growing environments.

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