• Title/Summary/Keyword: Joint Quality

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Joint Width Design for Post-Tensioned Concrete Pavement (포스트텐션 콘크리트 포장의 줄눈 폭 설계)

  • Kim, Dong-Ho;Kil, Yong-Su;Kim, Jin-Woung;Yun, Kyeong-Ku
    • International Journal of Highway Engineering
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    • v.12 no.3
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    • pp.147-154
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    • 2010
  • In post-tensioned concrete pavement(PTCP), one of the most important design variables is the initial joint width, in addition to the tensioning spacing. The joint width between PTCP slabs directly affects noise and ride quality. If the joint width is too wide, noise increases and ride quality decreases. If the initial joint width is too narrow, on the other hand, under high temperature, PTCP slabs can blow up, or failures near the joint can occur due to excessive compressive stresses. This study was conducted to determine the optimal initial joint width of PTCP and to investigate the joint width behavior under temperature changes. The experiments were performed using one-year-old PTCP slabs. The concrete temperatures were measured using the temperature measurement sensors installed at various depths. The joint widths were measured using vernier-calipers at different times of a day and the relationship between the joint width and temperature was analyzed. From this study, the design methodology to determine the optimal initial joint width of PTCP could be proposed.

A Study on the application for Z-Quality steel (Z-Quality 강재 적용에 대한 고찰)

  • Park, Sungjun;Ha, Yunsok
    • Special Issue of the Society of Naval Architects of Korea
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    • 2017.10a
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    • pp.8-13
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    • 2017
  • The rolled carbon steel plate has anisotropic property in Z-direction(thickness direction). This is induced by cooling rate difference of Z-direction and sulfur which make non-metallic inclusion(MnS) at center line of thickness direction. Z-directional mechanical properties of normal steel plate are not generally specified and it is defined for Z-Quality steel only through tensile test in Z-direction. If Z-quality steel is not applied for cruciform joint, the lamella tearing will be occurred by tensile stress after welding & during operation of the structure. In this research, one equation estimating Z-directional(orthogonal to plate) stress was developed to prevent lamella tearing by welding. This equation deals with plate thickness & joint configuration(eccentricity, angle and curvature). Analyses were done by strain boundary method using sectional FE modeling and FE 3D models are also used for some cases. Designers can predict the possibility of lamella tearing by adequately applying the result and can appropriately minimize the application of Z-quality steel by revising welding design to some extent.

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Factors influencing Health-related Quality of Life in Older Adults with Osteoarthritis: Based on the 2010-2011 Korea National Health and Nutrition Examination Survey (골관절염 노인의 건강 관련 삶의 질 영향요인: 국민건강영양조사 자료를 이용하여)

  • Kim, Minju;Bae, Sun Hyoung
    • Journal of muscle and joint health
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    • v.21 no.3
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    • pp.195-205
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    • 2014
  • Purpose: This study was conducted to identify factors that influence health-related quality of life in older adults with osteoarthritis. Methods: This study used a cross-sectional design with secondary analysis of the Korean National Health and Nutrition Examination Survey 2011. A total of 362 participants aged 65 years and older who had osteoarthritis were selected. Health-related quality of life using EQ-5D, perceived health status, body mass index, numbers of chronic illness, smoking and alcohol use, exercise, activity limitation, joint pain and stiffness, depression, and perceived stress were measured. Descriptive statistics, $x^2$-test, t-test, ANOVA, Pearson's correlation coefficients, and multiple regression were conducted with SPSS/WIN 21.0. Results: The mean score of EQ-5D was 0.77 in older adults with osteoarthritis. The results of multiple regression analysis showed that age, income, subjective health status, restriction of activity, knee joint stiffness, depressive mood, and perceived stress significantly predicted health-related quality of life in older adults with osteoarthritis, explaining 42% of the variance. Conclusion: Older adults with osteoarthritis have low health-related quality of life. In oder to improve health-related quality of life in older adults with osteoarthritis, it is important not only to enhance physical function but also to provide emotional support.

Behavior and Design of Terminal Joint Width between Post-Tensioned Concrete Pavement and Jointed Concrete Pavement under Temperature Changes (온도변화에 따른 PTCP와 JCP 접속부 줄눈 폭 변화와 설계 방안)

  • Kim, Dong-Ho;Lee, Bong-Hak;Kim, Seong-Min;Park, Seong-Tae
    • International Journal of Highway Engineering
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    • v.13 no.1
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    • pp.223-228
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    • 2011
  • The initial joint width design of the terminal joint between post-tensioned concrete pavement (PTCP) and jointed concrete pavement (JCP) was studied in this research. The joint width between PTCP and JCP directly affects noise and ride quality. If the initial joint width is very large, noise increases and ride quality decreases. If the initial joint width is very small, on the other hand, under high temperatures, PTCP slabs can blow up, or failures near the joint can occur due to excessive compressive stresses. The terminal joint width behavior between PTCP and JCP near Jumunjin at Donghae expressway under temperature changes was measured in August and November 2010 and the data was analyzed. From this study, the design methodology of the optimal initial terminal joint width was proposed.

Watertightness Property Evaluation of Rain-Block System (개폐식 대공간 구조물에서 지붕 맞댐부 우수차단 시스템의 수밀성 평가에 관한 연구)

  • Kim, Yun-Ho;Baek, Ki-Youl;Kim, Jong-Su;Lee, Sun-Gyu;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2010.05a
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    • pp.13-16
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    • 2010
  • This study is an Investigation on the Watertightness Properties of Rain-Block System on the Sliding-Roof Joint of Large-Span Membrane Structures. In this experimental, we test the watertightness performance of joint part of sliding door in roof of large span membrane structure(for pilot project) under environment of rain and wind. A shape of rain water blocking systems of joint part in sliding door verifies the defects and effects of water leakage prevention in precipitation with the wind conditions. For obtaining watertightness of large span membrane structures, it is necessary quality of joints and performance, and quality of membrane material of a retractable roof as well as a closed roof. Also, for obtaining quality in joints, it is essential to make a watertightness guideline for design of large-span membrane.

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The Joint Frequency Function for Long-term Air Quality Prediction Models (장기 대기확산 모델용 안정도별 풍향·풍속 발생빈도 산정 기법)

  • Kim, Jeong-Soo;Choi, Doug-Il
    • Journal of Environmental Impact Assessment
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    • v.5 no.1
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    • pp.95-105
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    • 1996
  • Meteorological Joint Frequency Function required indispensably in long-term air quality prediction models were discussed for practical application in Korea. The algorithm, proposed by Turner(l964), is processed with daily solar insolation and cloudiness and height basically using Pasquill's atmospheric stability classification method. In spite of its necessity and applicability, the computer program, called STAR(STability ARray), had some significant difficulties caused from the difference in meteorological data format between that of original U.S. version and Korean's. To cope with the problems, revised STAR program for Korean users were composed of followings; applicability in any site of Korea with regard to local solar angle modification; feasibility with both of data which observed by two classes of weather service centers; and examination on output format associated with prediction models which should be used.

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Analysis of Research Papers Published in the Journal of Muscle and Joint Health on Research Trends, Nursing Intervention and Quality Assessment of Intervention Studies (2013~2015년 근관절건강학회지 게재 연구의 동향, 실험중재 및 연구의 질 평가)

  • Jeon, Mi Yang;Eun, Young;Lee, Eun Nam;Min, Hye Sook;Bak, Won-Sook;Choi, Mi-Kyung;Song, Rhayun;Lee, Inok;Choi, Hee Kwon;Shin, Gyeyoung;Kim, Minju;Lee, Kyung-Sook;Lee, Myung Sook;Cho, Kyung-Sook;Kim, Ju Sung;Chung, Yeo Sook
    • Journal of muscle and joint health
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    • v.23 no.3
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    • pp.214-224
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    • 2016
  • Purpose: This study aimed to analyze recent trends in nursing research published in the Journal of Muscle and Joint Health by focusing on the content of nursing interventions and their quality. Methods: A total of 80 studies published between 2013 and 2015 were reviewed using analysis criteria developed by the researchers. Results: Quantitative studies accounted for 98.7% while qualitative studies accounted for 2.3%. Most frequently used research designs were quasi-experimental (92.9%) for experimental research and survey (89.4%) for non-experimental research. Patients (43.8%) were the most frequent study participants. Elderly was the most frequently used keyword. Most frequent nursing interventions were exercise (35.7%). Self-efficacy (35.7%), flexibility (28.6%) and pain (28.6%) outcomes for dependent variables were used. Quality assessment of experimental studies by SIGN were high quality (25%), acceptable (50%), low quality (25%). Conclusion: The results suggest that further expansion of randomized controlled trial and qualitative studies. To enhance the quality of research, It is needed to try the intention to treat analysis in experimental research.

Weld Quality of MCFC Separators With Large Active Area (MCFC용 대면적 분리판의 용접부 품질에 관한 고찰)

  • Kim, K.C.;Jun, J.H.;Kim, S.G.;Kuk, S.T.;Lim, H.C.;Jung, B.S.
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.135-138
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    • 2009
  • Quality evaluation of laser welded MCFC separator panels with large active area was performed. Lap joint was applied to produce stable air-tight seam weld by employing Nd:YAG laser. Results showed that surface contamination played a key role to form weld defects at the joint interface. However, there was no evidence that weld width at the lap joint changed after the stack operation time of 2,890h. Test results also revealed that the reinforcement values which were measured on the weld line after long time operation, were stable.

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Evaluation of Clinical Efficacy and Safety Following Kyungokgo-Gamibang Administration in Dogs with Skin and Joint Diseases

  • Ga-Won Lee;Heyong-Seok Kim;Jong-Won Kim;Yang-Seon Moon;Chang-Su Na
    • Journal of Veterinary Clinics
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    • v.40 no.2
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    • pp.113-118
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    • 2023
  • Skin and joint diseases are relatively common in dogs. Nutritional complementation is one of the various management strategies for these disorders. This study evaluated the safety and clinical efficacy of Kyungokgo-gamibang in dogs with skin and joint diseases. Thirty dogs with diseases were included and divided into three groups: control group (n = 15), skin group (n = 10), and joint group (n = 5). The skin and joint groups were fed skin and joint gums composed of Kyungokgo-gamibang extract with standard treatment for four weeks. The control group included dogs with skin diseases who were administered standard skin infection treatment for 4 weeks. The physical and laboratory results showed no remarkable adverse effects of Kyungokgo-gamibang extract after its administration in dogs. Clinical efficacy was evaluated using quality of life scale, and levels of cytokines, including interferon-γ, interleukin (IL)-2, IL-6, IL-8, IL-10, monocyte chemoattractant protein-1, and tumor necrosis factor-α, for 4 weeks in all groups. Dermatologic clinical scales were performed for 4 weeks in the control and skin groups. Both the control and skin groups had significantly decreased dermatologic clinical scales, including pruritus and erythema scales (p < 0.05). Among the cytokine levels, only IL-2 concentration was significantly decreased in the skin group after 4 weeks of administration of the Kyungokgo-gamibang extract (p = 0.032). There was no significant difference between the levels of cytokines on days 0 and 28 in the joint group. The quality of life scale was significantly increased after week 4 compared to week 0 in the skin (p = 0.008) and joint groups (p = 0.041). This study suggests that Kyungokgo-gamibang extract can be applied in managing dogs affected by skin and joint diseases without adverse effects.

Minimization of Welding Defect in $CO_2$ Laser Welded Tube

  • Suh Jeong;Kang Hee-Shin;Lee Jae-Hoon;Park Kyoung-Taik;Lee Moon-Yong;Jung Byung-Hun
    • International Journal of Precision Engineering and Manufacturing
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    • v.6 no.3
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    • pp.19-23
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    • 2005
  • To minimize the weld defect in manufacturing of the welded tube by using $CO_2$ laser, the monitoring of the welding quality and the seam tracking along the butt-joint lengthwise to the tube axis are studied. The longitudinal butt-joint is shaped from $60kgf/mm^2$ grade steel sheet by 2 roll bending method, and welded by the $CO_2$ laser welding system equipped with the seam tracker and plasma sensor. The laser welded tube has the thickness of 1.5mm, diameter of 105.4mm and length of 2000mm. The precise positioning of the laser beam on the butt-joint to be assembled is obtained within $200{\mu}m$ by the laser vision sensor. The artificial defects in the butt-joint are well observed by the signal of plasma intensity measured from the plasma sensor of UV wavelength range within 400nm. The developed $CO_2$ laser tube welding system has the function of the precision seam tracking and the real-time monitoring of the welding quality. In conclusion, the laser welded tube can be used for manufacturing of automobile chassis and components after hydro-forming.