• Title/Summary/Keyword: strength design method

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Numerical modelling of FRP strengthened RC beam-column joints

  • Mahini, Seyed S.;Ronagh, Hamid R.
    • Structural Engineering and Mechanics
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    • v.32 no.5
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    • pp.649-665
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    • 2009
  • This paper reports part of a comprehensive research study conducted at the University of Queensland on the ability of CFRP web-bonded systems in strengthening an exterior beam-column joint subjected to monotonic loads. One 1/2.2 scaled plain and four CFRP repaired/retrofitted joints subjected to monotonic loads were analysed using the nonlinear finite-element program ANSYS and the results were calibrated against experiments. The ANSYS model was employed in order to account for tension stiffening in concrete after cracking and a modified version of the Hognestad's model was used to model the concrete compressive strength. The stress-strain properties of main steel bars were modelled using multilinear isotropic hardening model and the FRPs were modelled as anisotropic materials. A perfect bond was assumed as nodes were shared between adjacent elements irrespective of their type. Good agreement between the numerical predictions and the experimental observation of the failure mechanisms for all specimens were observed. Closeness of these results proved that the numerical analysis can be used by design engineers for the analysis of web-bonded FRP strengthened beam-column joints with confidence.

Influence of Emotional Labor on Job Satisfaction, Intent to Leave, and Nursing Performance of Clinical Nurses (감정노동의 하부요인이 병원간호사의 직무만족, 이직의도 및 간호업무성과에 미치는 영향)

  • Wi, Sun-Mee;Yi, Yeo-Jin
    • Journal of Korean Academy of Nursing Administration
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    • v.18 no.3
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    • pp.310-319
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    • 2012
  • Purpose: The purpose of this study was to analyze emotional labor factors influencing job satisfaction, intent to leave, and nursing performance of clinical nurses. Method: The participants were 384 clinical nurses working in a hospital. Study design was cross sectional survey. Subcategories of emotional labor (frequency of emotional labor, attentiveness of emotional display, mismatch of emotions) of emotional labor were dependent variables. Job satisfaction, intent to leave, and nursing performance were independent variables. Data were analyzed by hierarchial multiple regression. Results: The strength of emotional labor of nurses was similar for all participants in spite of differences in age, position, and clinical career. Total score for emotional labor was 3.21, frequency of emotional labor 3.34, attentiveness of emotional display 3.41, and mismatch of emotions 2.87. Mismatch of emotions influenced job satisfaction (F=12.53, p<.001) $R^2$ 27%, intent to leave (F=8.51, p<.001) $R^2$ 19%, and nursing performance (F=5.80, p<.001) $R^2$ 15%, Conclusion: These findings indicate that the factor (mismatch of emotion) is an important variable for clinical nurses in human resource management. Therefore, nurse managers should consider this factor for the improvement of organizational effectiveness.

Fatigue Associated with Kidney Disease Symptoms in Female Patients Undergoing Hemodialysis (혈액투석을 받는 여성의 피로와 신 질환증상의 관련성)

  • Song, Hyo-Jeong;Kim, Hyeon-Ju
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.14 no.4
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    • pp.474-482
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    • 2007
  • Purpose: This study was done to provide fundamental data for nursing interventions to prevent and reduce fatigue and to identify fatigue and kidney disease symptoms in female patients on hemodialysis and evaluate factors associated with this fatigue. Method: A cross-sectional study design was used with self-administered questionnaires which included general characteristics and the fatigue scale developed by Brown, Dittner, Findly, & Wessely(2005)(Cronbach's $\alpha=0.98$ and for present study $\alpha=0.96$) and a review of laboratory data. From eight dialysis units, 84 women were enrolled. Data were analyzed using the SAS program. Results: Mean score for fatigue was 49.4(range $16{\sim}78$) and fatigue by research variables was significantly different by age(0.046), employment status(0.041), menopause(0.009), hypoalbuminemia(0.022), length of time on dialysis(0.48) and kidney disease symptoms(0.000). Correlations between fatigue and lack of strength, dizziness, and cramps after dialysis were significantly higher. Factors affecting fatigue were kidney disease symptoms and length of time on dialysis, explaining 49.2% of fatigue. Conclusion: A comprehensive approach considering kidney disease symptoms, length of time on hemodialysis, age, menopause, and hypoalbuminemia are required for interventions to reduce fatigue in female patients on hemodialysis.

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Development of a Dan J eon Breathing Model for Health Promotion in Middle-aged Women (중년여성의 건강증진을 위한 단전호흡 모형 개발)

  • Kim Kyung-Won
    • Journal of Korean Academy of Nursing
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    • v.35 no.3
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    • pp.565-574
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    • 2005
  • Purpose: The purpose of this study was to develop a Dan Jeon Breathing Model and to identify effects of the developed Dan Jeon Breathing Model for maintenance and promotion of health and improvement of health problems in middle-aged women. Method: This study was constructed with two procedures. The first procedure was to develop appropriate movements for middle-aged women, performing a focus group discussion and developing a Dan Jeon Breathing Model in qualitative research. The collected data from focus group discussions was categorized for fitting movements. The second procedure was to verify and conclude a Hypothetic Dan Jeon Breathing Model through a quasi-experimental nonequivalent control group pre-post test design. Result: The developed Dan Jeon Breathing Model was composed of 28 preparation movements to accept Ki comfortably, 10 breathing movements to accumulate Ki for activation of metabolic function in organs and 14 finishing movements to transmit activated Ki to organs. It took 40 minutes to do them. In the Second procedure, the score of physical health (t=4.205, p=.000), psycho-social health(t=3.292, p=.002) and physical strength of the experimental group(t=5.905, p=.000) was higher than that of the control group. Conclusion: The Dan Jeon Breathing Model developed in this study is the correct health promotion model for middle-aged women, their demand, developmental traits and health problems.

Development and Effectiveness of a Program for Relieving ′Hwa-Byung′ Symptoms (화병관리프로그램 개발 및 효과)

  • Park Young-Joo;Kim Jong-Woo;Cho Sung-Hoon;Moon So-Hyun
    • Journal of Korean Academy of Nursing
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    • v.34 no.6
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    • pp.1035-1046
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    • 2004
  • Purpose: This one group experimentation was designed to develop a program for relieving 'Hwa-Byung'(HB) symptoms and examine its effects on HB symptoms, pain threshold emotions like anger, anxiety and depression. Method: The program consisted of three components the change of the cognitive thoughts, the formation of a supportive network, and induction of mind-body relaxation. Sixteen middle-aged women with HB were divided into three groups for group dynamics according to the time of the recruitment. Data was collected for nine months at three time points, before, immediately after, and one month later of its application. Result: There were statistically significant differences in the severity level of state anger, state anxiety, depression, and HB symptoms according to the time interval. The means of state anger and state anxiety were reduced after the intervention, but it was slightly increased one month later. The means of depression and HB symptoms were continuously reduced after the intervention and one month later. Conclusion: This was the first management program for HB women in Korea. A future study must be done with the research design formethodological strength revision of the program.

Development of Hot die Forging Process for Large-size Titanium Alloy Container (대형 티타늄 합금 용기의 고온 금형 성형 공정 개발)

  • Kwon, I.K.;Kim, D.S.;Park, T.D.;Park, H.S.;Hong, S.S.;Shim, I.O.
    • Transactions of Materials Processing
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    • v.19 no.1
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    • pp.50-58
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    • 2010
  • In order to successfully implement hot die forging process for the large-size titanium alloy products, it is necessary to devise a customized heating method for the billets and the die tools, as well as the die tool design. This study aims at establishing a hot die forging process of the large-size titanium alloy container products by applying the warm die, semi-hot die and hot die forging process step-wise. To accomplish this purpose, forging mechanism and the die tools were designed considering the strength of die materials at the given die heating temperature. The movable heating devices for the billet and the die tools were also introduced to prevent overcooling of billet and die tools. To verify the applicability of the designed forging process, real-size forging tests were carried out and the quality of forged products, including dimension, surface condition, microstructure and the mechanical properties was evaluated.

On the Numerical Procedure for Estimating Structural Stress of Welded Structures (수치해석을 통한 용접구조물의 구조응력 추정에 관한 연구)

  • Kang, Sung-Won;Kim, Myung-Hyun
    • Journal of the Society of Naval Architects of Korea
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    • v.42 no.4 s.142
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    • pp.388-395
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    • 2005
  • A numerical procedure is proposed as a mesh-size insensitive structural stress definition that gives a stress state at a weld toe with relatively large mesh size. The structural stress values obtained using different finite element types, i.e. shell element and solid element, are examined for typical weld structures. The calculation procedures are performed using the balanced nodal forces and moments obtained from finite element solutions. A consistent formulation based on work equivalent argument has been implemented to transform the balanced nodal forces and moments from shell to line force and line moments at each nodal position. The mesh-insensitivity, the effect of distance $\delta$(where the stress is calculated) and the potential limitations of the structural stress method are examined for various types of weldments. Based on the results from this study, it is expected to develop a more precise stress estimation technique for fatigue strength assessment of welded structures.

The Development and Effect of a Tailored Exercise Program on Physical Fitness in Patients with Parkinson's Disease (파킨슨병 맞춤운동프로그램의 개발 및 신체기능에 대한 효과)

  • Sohng, Kyeong-Yae;Moon, Jung-Soon;Lee, Kwang-Soo;Choi, Dong-Won
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.13 no.3
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    • pp.390-400
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    • 2006
  • Purpose: To develop & to examine the effect of a Tailored Exercise Program (TEP) on physical fitness in patients with Parkinson's disease (PD). Method: In a two-group pre-and post-test design, from a total 41 participants. 21 were assigned th the experimental group find the remainder to the control group. The experimental group participated in a 4-day a week, 8 week program in which one session a week was by direct instruction with the self-help group and two sessions a week were by videotaped instruction at home by themselves. The control group did not receive any intervention. Results: The eight week TEP in patients with PD was found to be significantly effective in enhancing muscle strength, ankle flexibility, and balance. However instrumental activities of daily living was not changed by the intervention. Conclusion: These results suggest that TEP can have an effect on physical fitness in patients with PD. Further research with a larger sample and for a longer follow up period is needed to expand our understanding of the effects of TEP for patients with PD.

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A Study on Power Control with Improved SIR in DS-CDMA System (DS-CDMA에서 개선된 SIR을 이용한 전력 제어에 관한 연구)

  • 이강훈;최정희;박용완
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.6
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    • pp.994-1001
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    • 2001
  • In this paper, we propose the Improved SIR-based Power Control method in mobile communication system. Generally speaking, SIR-based design considering both channel noise and multiuser interference is accurate indication of signal quality and provides good performance. However, one serious problem associated with SIR-based Power Control is the potential of Positive Feedback which can endanger the stability of the system. Therefore from SIR definition, we decrease the signal\`s Interference we will got a improved SIR and have a stable power control Also in mobile using window register which has Up-Maintain-Down power control step size instead of Up-Down, we got a better performance. This paper assesses the performance of Improved SIR based Power Control using PIC and window register. The proposed Improved SIR based Power Control is presented and compared with existing SIR based Power Control and Strength-and-SIR based Power Control.

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Optimum Selection of the Advanced Indentation Technique for the Evaluation of Non-equip-biaxial Residual Stress in Steel Materials (철강 재료의 2축 비등방향 잔류응력 평가를 위한 연속압입시험의 최적조건 선정)

  • Yu S.J.;Kim J.H;Park J.S.;Kwon D.I.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.1774-1779
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    • 2005
  • Most of materials receive force in using, therefore, the characteristics of materials must be considered in system design not to occur deformation or destruction. Mechanical properties about materials can be expressed as responsible level of material itself under the exterior operation. Main mechanical properties is strength, hardness, ductility and stiffness etc. Currently, among major measure facilities to measure such mechanical properties, advanced indentation technique has focused in industrial areas as reason of nondestructive and easy applications for mechanical tensile properties and evaluation of residual stress of materials. This study is to find the optimum experimental condition about residual stress advanced indentation technique for accurate analysis of the welded joint of steel materials through indentation load-depth curve obtained from cruciform specimen experiment. Optimum selection was applied to the welded joint of real steel materials to give non-equi-biaxial stress state and compared with general residual stress analyzing method for verification.

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