• Title/Summary/Keyword: two stress factors

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Stress Intensity Factor Analysis of Elliptical Arc Through Cracks at Mechanical Fastener Holes by Weight Function Method ( I ) - Development of Weight Function Method - (가중함수법에 의한 기계적 체결홀에 존재하는 타원호형 관통균열의 음력확대계수 해석 ( I ) - 가중함수법의 전개 -)

  • Heo, Seong-Pil;Yang, Won-Ho;Hyeon, Cheol-Seung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.10
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    • pp.1659-1670
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    • 2001
  • It has been reported that cracks at mechanical fastener holes usually nucleate as elliptical corner cracks at the faying surface of the mechanical joints and grow as elliptical arc through cracks after penetrating the opposite surface. The weight function method is an efficient technique to calculate the stress intensity factors fur elliptical cracks using uncracked stress field. In this study the weight function method for three dimensional mixed-mode problem applied to elliptical comer cracks Is modified for elliptical arc through cracks and the stress intensity factors at two surface points of elliptical arc through cracks at mechanical fastener holes are analyzed by the weight function method. This study consists of two parts and in part I , the weight function method for elliptical arc through cracks is developed and verified.

The Mental Health of Hospital Workers During the Initial Phase and Third Wave of the COVID-19 Pandemic: Exploring Risk and Protective Factors in the Prolonged Pandemic

  • Choi, Huiyoung;Lee, Wangjun;You, Myoungsoon;Chang, Jhin Goo;Hong, Minha;Kim, Hyun-Soo;Lee, Su Young
    • Anxiety and mood
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    • v.18 no.2
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    • pp.80-91
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    • 2022
  • Objective : Hospital workers' mental health has deteriorated because of the ongoing COVID-19 pandemic. The purpose of this study was to investigate the impact of the prolonged COVID-19 pandemic on the mental health of hospital workers and its determinants. Methods : Two surveys were conducted among employees working in a hospital that received COVID-19 patients from the early phase of the pandemic in South Korea. Data on demographics, perceived threat, workplace evaluation, resilience, and mental health status were collected using the Korean General Health Questionnaire-20 in the initial phase (February 2020) and during the third wave of COVID-19 (December 2020) for 467 and 545 workers, respectively. The mental health of hospital workers in the two phases was compared, and the risk and protective factors during the third wave were investigated. Results : The proportion of patients in the psychiatric high-risk group increased from 2.8% in the initial phase to 11.4% during the third wave. The perceived threat, workplace evaluation, and resilience of respondents deteriorated. Risk factors for mental health during the third wave included the perceived threat items of job stress, loss of control, and considering resignation. Protective factors included presence of children, workplace satisfaction, and hardiness in resilience. Conclusion : Hospital workers' mental health deteriorated as the pandemic progressed. General stress and tension such as job stress, loss of control, considering resignation rather than COVID-19-specific stress had negative effects on mental health of hospital workers. Therefore, care for work stress itself can be helpful to maintain the mental health of hospital workers. Also, governance to improve workplace satisfaction or hardiness in resilience can be a potential protective factor for hospital workers' mental health during the prolonged pandemic.

Mode I and Mode II Stress Intensity Factors for a Surface Cracked in TiN/Steel Under Hertzian Rolling Contact (Hertzian 접촉하중시 TiN/Steel의 표면균열에 대한 모드 I과 모드 II 응력확대계수)

  • Kim, Byeong-Su;Kim, Wi-Dae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.8
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    • pp.1163-1172
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    • 2001
  • The two dimensional problem of a layered tribological system(TiN/Steel) containing a vertical surface breaking crack and subject to rolling contact is considered in this study. Using finite elements and stress extrapolation method, a series of preliminary models are developed. Preliminary results indicate that the extrapolation technique is valid to determine Modes I and II stress intensity factors for cracks. In the case of TiN/Steel medium, KI and KII were determined for variations in crack length, layer thickness, and load location. The results show that KII reaches maximum values when the contact is adjacent to the crack where Mode I stresses are compressive. KII values decrease with decreased crack length and significantly decrease for reduced layer thickness.

An Analysis of the Vowel Formants of the Young Females in the Buckeye Corpus (벅아이 코퍼스에서의 젊은 성인 여성의 모음 포먼트 분석)

  • Yoon, Kyuchul
    • Phonetics and Speech Sciences
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    • v.4 no.4
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    • pp.45-52
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    • 2012
  • The purpose of this paper is to measure the first two vowel formants of the ten young female speakers from the Buckeye Corpus of Conversational Speech [1] automatically and then to analyze various potential factors that may affect the formant distribution of the eight peripheral vowels of English. The factors that were analyzed included the place of articulation, the content versus function word information, the syllabic stress information, the location in a word, the location in an utterance, the speech rate of the three consecutive words, and the word frequency in the corpus. The results indicate that the overall formant patterns of the female speakers were similar to those of earlier works. The effects of the factors on the realization of the two formants were also similar to those from the male speakers with minor differences.

Effect of the Semi-circular Relieving Groove on the Stress Concentration at the Fillet of the Stepped Bar under Axial Tension (축인장하(軸引張下)의 평판(平板)의 단부(段部) Fillet 근처(近處)의 Relieving Groove가 응력집중(應力集中)에 미치는 영향(影響))

  • Hyo-Chul,Kim
    • Bulletin of the Society of Naval Architects of Korea
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    • v.6 no.2
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    • pp.5-10
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    • 1969
  • A stepped bar with seimi-circular stress relieving groove near the fillet was subjected by axial tension in a polarized light field. On the stress concentration factor, the effect of the ratios of the fillet radius, the distance between two relieving grooves and the groove radius to the breath of the narrower portion of the stepped bar have been investigate. Observing the stress concentration in 48 models with various proportions, the conclusion arrived at were as follow: 1) If the fillet radius of the stepped bar is larger than half breadth of the narrower portion, the reduction of the stress concentrations can not be expected. 2) If the fillet radius is smaller than half breadth of the narrower portion of the stepped bar, the stress concentration can be droped to the reasonable range. 3) When the groove radius is larger than a quarter of the difference between the distance of two relieving grooves and the breadth of the stepped bar and smaller than a half of that, the stress concentration factors can have their possible minimum value. 4) When the sun of the breadth of the narrower portion of the stepped bar and twice of the relieving groove radius is smaller than the distance between two relieving grooves, minimum stress concentration can be obtained.

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The Relationship Between Emotional Labor and Job Stress of Clinical Nurses in a Hospital (일개 병원 임상간호사의 감정노동과 직무스트레스에 관한 연구)

  • Ahn, Ji Young;Jung, Hye-Sun;Kim, Hyeong A
    • Korean Journal of Occupational Health Nursing
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    • v.16 no.2
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    • pp.139-146
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    • 2007
  • Purpose: The purpose of this research is to understand the relationship between emotional labor and job stress for clinical nurses. Method: The information for this research has been gathered in method of questionnaire for 202 nurses working in a hospital from January 30 to February 10, 2006. Results; The emotional labor for clinical nurses showed 2.43 on a scale of 4 and the job stress showed 49.84 out of 100. The correlation between the emotional labor and job stress showed that the emotional labor was higher, job stress was also higher. The result was that the factors that influenced the emotional labor were health status in a subjective point of view, working department, and the personality. The factors that influence job stress were self-efficacy, working department, and health status in a subjective point of view. Conclusion: The result of the research showed that emotional labor and job stress for clinical nurses were high and the strategy for reduction in those two areas is needed. Especially, diversified plans for job demand and occupational climate in an area of job stress that is correlated to emotional labor will be needed to minimize the emotional labor and job stress.

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Factors influencing maternal-fetal attachment in pregnant women during the COVID-19 pandemic: a cross-sectional study

  • Hyeryeong Yoon;Hyunkyung Choi
    • Women's Health Nursing
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    • v.29 no.1
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    • pp.55-65
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    • 2023
  • Purpose: Coronavirus disease 2019 (COVID-19) has spread widely throughout the world, causing psychological problems such as fear, anxiety, and stress. During the COVID-19 pandemic, pregnant women have been concerned about both their own health and the health of their fetuses, and these concerns could negatively affect maternal-fetal attachment. Thus, this study aimed to explore the level of COVID-19 stress, resilience, and maternal-fetal attachment among pregnant women during the COVID-19 pandemic, and to identify factors influencing maternal-fetal attachment. Methods: In total, 118 pregnant women past 20 weeks gestation were recruited from two maternity clinics in Daegu, Korea, to participate in this descriptive correlational study during COVID-19. The factors influencing maternal-fetal attachment were analyzed using hierarchical multiple regression analysis. Results: The mean scores for COVID-19 stress, resilience, and maternal-fetal attachment were 57.18±10.32 out of 84, 67.32±15.09 out of 100, and 77.23±9.00 out of 96, respectively. Nulliparous pregnant women reported greater maternal-fetal attachment than multiparous pregnant women (p=.003). Religious pregnant women also reported greater maternal-fetal attachment than non-religious pregnant women (p=.039). Resilience (β=.29, p=.002), COVID-19 stress (β=.20, p=.030) and parity (β=-.17, p=.047) were factors influencing maternal-fetal attachment, and these factors explained 26.4% of the variance in maternal-fetal attachment (F=10.12, p<.001). Conclusion: Converse to common sense, COVID-19 stress exerted a positive influence on maternal-fetal attachment in pregnant women during the COVID-19 pandemic. Healthcare providers need to recognize the positive influence of COVID-19 stress and implement intervention strategies to strengthen resilience in pregnant women to improve maternal-fetal attachment.

Spondylolisthesis Accompanying Bilateral Pedicle Stress Fracture at Two Vertebrae

  • Kim, Hyeun-Sung;Kim, Seok-Won;Lee, Won-Tae
    • Journal of Korean Neurosurgical Society
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    • v.51 no.6
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    • pp.388-390
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    • 2012
  • There has been no report of bilateral pedicle stress fractures involving two vertebrae. The authors describe a unique case of spondylolisthesis accompanying a bilateral pedicle stress fracture involving two vertebrae. De novo development of spondylolisthesis at the L5-S1 vertebrae accompanying a bilateral pedicle stress fracture at L4 and L5 was observed in a 70-year-old woman. The patient's medical history was unremarkable and she did not have any predisposing factors except severe osteoporosis. Interbody fusion with bone cement augmented screw fixation was performed. Surgical treatment resulted in good pain management and improved functional recovery.

The Effects of Psychosocial Stress and Job Characteristics on Low Back Injury (사회심리적 스트레스 및 작업특성 요인이 직업성요통에 미치는 영향)

  • Heo, Guk-Gang;Park, Dong-Hyeon
    • Journal of the Ergonomics Society of Korea
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    • v.19 no.2
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    • pp.15-31
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    • 2000
  • The aim was to evaluate the prevailing ergonomic and psychosocial conditions regarding low back injury in an automobile assembly system. This study consisted of two parts. In the first part of the study, analytic biomechanical model and NIOSH guidelines were applied to evaluate risk levels of low back injury for automobile assembly jobs. Total of 246 workers were analysed. There were 20 jobs having greater back compressive forces than 300kg at L5/S1. Also, there were 44 jobs over Action Limit with respect to 1981 NIOSH guidelines. This might in part be explained by the ergonomic conditions of the company analysed generally being good, with a relatively low duration of 'combined' extreme work posture. The relationship between psychosocial factors and low back injury was examined in the second part of the study. It has recently been recognized that overall reaction to working conditions was influenced by a range of factors, some of which were physical and some psychosocial. The psychosocial environment surrounding the work place may contribute to the perception of risk and eventual ill-health. A battery of questionnaires concerning the psychosocial stress based on PWI(Psychosocial Well-being Index) and musculoskeletal pain symptoms at low back was completed by 246 workers at the same plant. Results showed that 207 out 246 workers experienced the symptoms and 27 workers were diagnosed as patients. Two groups(low stressed, high stressed) based on PWI score had no significant relationships with both symptoms and results of diagnosis. However, sensitivities for symptoms and diagnosis by PWI were 91.3% and 92.6% respectively. Finally, relationships between physical work load and psychosocial stress were analysed. Specifically, some postural factors {vertical deviation angle of forearm, horizontal deviation angle of upperarm, vertical deviation angle of thigh, etc) were highly correlated with psychosocial stress. The results illustrated that PWI scores were associated with some physical workloads. However, psychosocial stress levels couldn't be well related with the pain symptom as well as the actual incidence of low back injury since pain or discomfort regarding low back injury were more complex than that of other musculoskeletal disorders.

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The Study of Health Promotion Behavior of Nursing College Student by the Self-Esteem (간호대학생의 자아존중감에 따른 건강증진행위에 미치는 요인)

  • Yoon, Hee-Sang
    • The Journal of Korean Society for School & Community Health Education
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    • v.11 no.2
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    • pp.115-127
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    • 2010
  • Objectives: This study was carried out to investigate the effects of improvement in health promotion behavior of nursing college students by the difference of self esteem. The students was divided two groups one is low level self esteem the other is high depending on median point of self esteem. The specific objectives were first, to find out the differences of health promotion behavior, self efficacy, health perception, fatigue level, depression, psychosocial wellbeing, second, to establish which factors determine their health promotion behavior between two groups. Methods: Self-administered questionnaires were given to 262 students enrolled in a nursing college. between may and June 2008. The questionnaire items included age, sex, education level, self esteem, self efficacy, health perception, fatigue, depression,, psychosocial well being and health promotion behavior. For statistical analysis, frequency, t-test, regression used for determining the factors effecting health promotion behavior. Results: The influencing factors were self efficacy among low level and self efficacy, fatigue and stress among high level. Self efficacy strong positive impact on health promotion behavior among both groups. Stress and fatigue was only effective among high level group. Conclusion: Based on the study results, improvement of health promotion behavior among nursing students requires the development and application of programs to manage self efficacy and stress as a precondition for depending on self esteem level.

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