• Title/Summary/Keyword: Fatigue Variable

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Reliability Analysis of Steel Fiber Reinforced Concrete Continuous Beams (강섬유 보강 철근콘크리트 연속보의 신뢰성 해석)

  • Yoo Han-Shin;Jang Hwa-Sup;Kwak Kae-Hwan
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.17 no.4
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    • pp.443-449
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    • 2004
  • Methods for mixing variable types of steel fibers have been developed recently to suppress outbreak of crack or to control the width of crack and improve the load resistible capacity at the same time. On the other hand, uncertainty by complex nature of destruction dynamics of steel fiber reinforced concrete(SFRC) is included. In this study, analysis of reliance considering uncertainty of SFRC beam is done. For this, intensity limit state model was proposed. Moreover, characteristic values about almost every kinds of probability variables were collected and presented according to home and foreign references. Process of improving uncertainty from the result of experiments by Bayseian updating method is also proposed on the purpose of offering better statistical characteristic values with more data in the new future. Fatigue fracture probability equation is proposed and needed statistical characteristic values were presented to analyze fatigue reliance

A Study on the relationship between Psychological stress, Compassion fatigue, Compassion satisfaction, and burnout of cyber counselors (사이버상담자의 심리스트레스, 공감피로 및 공감만족, 소진의 관계에 대한 연구)

  • Sung, Mi-Kyoung;Park, Sung-Hee
    • Journal of the Korea Convergence Society
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    • v.12 no.1
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    • pp.231-242
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    • 2021
  • The purpose of this study was to investigate the degree to which cyber counselors' psychological stress, Compassion fatigue and Compassion satisfaction affect exhaustion. 82 cyber counselors were surveyed, and 5 interviews were conducted. As a result of analysis to find out the degree of influence on exhaustion, it was found that Compassion satisfaction was a variable. In-depth interviews looked at the causes, consequences, and ways of overcoming exhaustion, and increased Compassion satisfaction, a positive emotion in the process of helping clients, lowers exhaustion, and shows that Compassion satisfaction is a protective factor to prevent exhaustion. Based on the research results, implications and limitations were discussed.

Cumulative damage in RC frame buildings - The 2017 Mexico earthquake case

  • Leonardo M. Massone;Diego Aceituno;Julian Carrillo
    • Advances in Computational Design
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    • v.8 no.1
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    • pp.13-36
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    • 2023
  • The Puebla-Morelos Earthquake (Mw 7.1) occurred in Mexico in 2017 causing 44 buildings to collapse in Mexico City. This work evaluates the non-linear response of a 6-story reinforced concrete (RC) frame prototype model with masonry infill walls on upper floors. The prototype model was designed using provisions prescribed before 1985 and was subjected to seismic excitations recorded during the earthquakes of 1985 and 2017 in different places in Mexico City. The building response was assessed through a damage index (DI) that considers low-cycle fatigue of the steel reinforcement in columns of the first floor, where the steel was modeled including buckling as was observed in cases after the 2017 earthquake. Isocurves were generated with 72 seismic records in Mexico City representing the level of iso-demand on the structure. These isocurves were compared with the location of 16 collapsed (first-floor column failure) building cases consistent with the prototype model. The isocurves for a value greater than 1 demarcate the location where fatigue failure was expected, which is consistent with the location of 2 of the 16 cases studied. However, a slight increase in axial load (5%) or decrease in column cross-section (5%) had a significant detrimental effect on the cumulated damage, increasing the intensity of the isocurves and achieving congruence with 9 of the 16 cases, and having the other 7 cases less than 2 km away. Including column special detailing (tight stirrup spacing and confined concrete) was the variable with the greatest impact to control the cumulated damage, which was consistent with the absence of severe damage in buildings built in the 70s and 80s.

The Evaluation of Lower Extremity Muscles in Combat shoes Custom Foot Orthotics (전투화 맟춤형 발보장구 착용 시 하지 근육 활동의 평가)

  • Suh, Sung-Hyeok;Kim, Ro-Bin;Cho, Young-Jae
    • Korean Journal of Applied Biomechanics
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    • v.18 no.2
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    • pp.115-124
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    • 2008
  • The purpose of this study was to examine the effects of customized foot orthotics on lower extremity muscle activity and fatigue during march in combat boots. Four volunteers with normal foot and five volunteers with excessive pronation foot among soldiers on service were fitted with foot orthotics. The electromyography signal from activity of low extremity muscles were collected with surface electromyography device during walking on the treadmill. The walk on the treadmill was performed with a speed of 4.5 km/h. The experiment design for reseach wes composed two experimentation. The first experiment was to examine the muscle activity of lower extremity between normal foot and excessive pronator foot during march. The second experiment was to examine the muscle activity of lower extremity between wearing orthotics and no wearing orthotics. These data were analyzed by the averaged integral EMG and the mean power frequency. The analyzed results were compared by independent T-test method and paired T-test method of SPSS(windows version 12.0). The result of the study were the muscle activity on pronator foot tend to increase during march but a statistically significant increase in muscle fatigue of vastus lateralis and fibularis longus. A statistically significant decrease in muscle activity of anterior tibialis and fibularis longus and fatigue occurred using the customized foot orthotics in volunteers with excessive pronation foot compared to volunteers with normal foot. Clinically, the application of orthotics for the soldiers with excessive pronation foot appears to delay muscle fatigue and prevent from variable foot injuries. This may contribute to enhancing fighting efficiency.

The study on the job stress of dental hygienists by the personality type (치과위생사 성격유형에 따른 업무 스트레스 연구)

  • Jung, Mee-Hee
    • Journal of Korean society of Dental Hygiene
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    • v.3 no.1
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    • pp.45-57
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    • 2003
  • The purpose of this study is to identify the factors affecting job stress and relationship between dental hygienists personal characteristics and them. Final purpose of this study provides the basic data of dental hygienists interventions to help dental hygienists' job stress reduction program. Data were drawn from a convenient sample of 401 dental hygienists who were working for dental clinic, general hospitals, and university hospitals in Seoul and Kyungi areas. The results were analyzed with spsswin 10.0 and the conclusion is as follow: 1. General special quality distribution of dental hygienist is 25-59 and respondent who work in the dentist's office by maiden less than was most. 2. The dental hygienists' job stress was 2.68, it indicates considerably high compare to normal another groups. 3. 'By work, feel fatigue' appeared highest by 3.60 in 5 points full marks from item of business amount connection stress. 4. Only business amount connection stress was expose that is significant in relation with job stress and individual character type. 5. Age, dependent's number, faith, character type variable appeared to keep in mind for connection factor which influence in job stress. 6. Job stress connection factor by character type was expose by variable savages significant thing 'that do work year all as dental hygienist' in A type.

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Meta-Analysis of the Research Findings Concerning Functional Relationships of Explanatory Variables to Hope (희망과 설명 요인과의 함수적 관계에 대한 메타 분석)

  • 김달숙;문원희;안성윤;오현숙;권경희;박문경;최현숙;이미옥;김영주
    • Journal of Korean Academy of Nursing
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    • v.34 no.5
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    • pp.673-684
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    • 2004
  • Purpose: The purpose of the study was to meta-analyze the relationships of major concepts, which were made by synthesizing similar explanatory variables into more comprehensive concepts, to hope. Method: The relevant researches from Jan 1980 to Dec 2003, performed in adults or adult patients, were collected. Using the SAS program, meta-analysis were done with the input data of the number of subjects, the correlation coefficients provided from most of the studies or a few transformed correlation coefficients from F value. In order to get the analysis to be done in homogeneous status of the data regarding each relationship of each major concept to hope(p> 0.05), heterogeneous data were eliminated in repeating Q-test. Result: The major variable regarding relationship to self/transcendental being/life(spiritual wellbeing & self esteem) and social support(social support & family support) have very large positive effects on hope(D=l.72, D=l.27). The negative effect of the variable regarding captive state(uncertainty in illness, perceived unhealthiness status, & fatigue) and positive effect of coping(approach coping) on hope are in the level between moderate to large(D=-0.61, D=0.78). All the effects of the major concepts on hope were verified as significant statistically(p=.000). The Fail -Safe numbers showed the significant effects of the three major concepts except coping on hope were reliable. Conclusion: The results can be a guide to advance hope theory for nursing.

The effect of muscle activity wristbands with mouse using (컴퓨터 마우스 보조기구 사용이 근활성도에 미치는 영향)

  • Lee, Tae-Sik;Song, Min-Young;Chea, Il-Jun
    • Journal of Korean Physical Therapy Science
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    • v.19 no.1
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    • pp.47-54
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    • 2012
  • Purpose : This study is to know the effect on muscle activity when people use mouse aid or not in computer working environment. Method : 11 people of both sex in their twentieth were tested. As a independent variable, the condition without mouse aid and the condition with movable mouse aid were selected, and as a dependent variable, MVC(%) on four muscles and inconvenience degree(RPE scale) on three body part(wrist, forearm, shoulder) were measured. Result : Analyzing the research, MVC(%) of extensor muscle of finger had notably higher muscle activity than other muscles, and there wasn't notable difference in muscle activity before and after using mouse aid. In case of using mouse aid, we tested by giving RPE questionnaire which segmentalized mental fatigue degree into hand, forearm, and shoulder, and resultingly, there wasn't notable differences perspectively. However, people felt less tiredness subjectively after they use the mouse aid. Conclusion : The usage of mouse aid seems to give comfort to computer users.

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An Exploratory Structural Analysis of the Accident Causing Factors in Railway Traffic Controllers (철도관제사의 사고유발 요인에 관한 탐색적 구조분석)

  • Kim, Kyung-Nam;Shin, Tack-Hyun
    • Journal of the Korea Society for Simulation
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    • v.27 no.1
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    • pp.119-126
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    • 2018
  • This study intended to exploratively testify human error causing factors for railway traffic controller, using AMOS structural equation model. Through literature survey, fatigue and stress as exogenous variable, errors in information process such as cognitive, memory, storage, and execution error as endogenous variable, and accident and incident(near-miss) as dependent variable were set up. Results based on AMOS using 201 railway traffic controllers' questionnaire showed that a clear causality loop like as 'stress ${\rightarrow}$ memory error ${\rightarrow}$ storage error ${\rightarrow}$ incident(near-miss) ${\rightarrow}$ accident' is formed. This result suggests that for the purpose of mitigation of traffic controller's accident, it is so necessary to reduce memory and execution error in the information processing process based on the effective management of stress, as the precedent of them.

Mediating Effects of Relief from Fatigue through Sleep and Perceived Subjective Health in the Relationship between Perceived Stress and Subjective Happiness in Middle School Who Attempted Suicide (자살시도 중학생의 스트레스와 주관적 행복감 (주관적 건강인지와 잠으로 피로회복정도의 평행다중매개모델))

  • Wi, Ok-Youn;Lee, Ji-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.4
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    • pp.229-238
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    • 2018
  • The purpose of this study is to examine the difference in the mediating effects of relief from fatigue through sleep and perceived subjective health in the relationship between perceived stress and subjective happiness in middle school students who attempted suicide. The analysis was conducted using Path analysis, the Bootstrapping method, Phantom variable and Multiple group analysis by AMOSS using the IBM SPSS 23 and IBM SPSS AMOS 23 programs with 820 middle school students who attempted suicide in the past 12 months using the raw data of the Korea Risk Behavior Web-Based Survey (2016). In the relationship between perceived stress and perceived subjective health, the indirect effect of relief from fatigue through sleep and perceived subjective health (${\beta}=-.12$, p=.003) was statistically significant. The difference in the magnitude of the two indirect effects was found to be greater for the subjective health status than for relief from fatigue through sleep (difference = .02, p=.028) and the effects were greater for the males (${\beta}=.44$, p <.001) than for the females (${\beta}=.23$, p<.001). Based on the findings, it is necessary to develop and apply an educational program that includes the factors that contribute to improving the happiness of middle school students.

Clinical Manifestation of Aging Voice (노인성 음성의 임상양상)

  • Baek, Min-Kwan;Kim, Dong Young
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.25 no.1
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    • pp.16-19
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    • 2014
  • The presbyphonia is a combination of physiological and structural changes due to aging of the larynx in elderly patients with voice problems. Some of these changes are inevitable, while others may be avoidable or reversible. The fatigue of phonation is the most common clinical symptom of the aging voice. The voice problems with aging are produced from variable causes including the organic lesions of the larynx. It is essential that the curers understand physiologic and pathologic changes of aging voice for minimizing glottal incompetence and improving vocal performance and quality of life of the elderly.

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