• Steel and Composite Structures
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• 제38권6호
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• pp.637-656
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• 2021

The component-based method is widely used to analyze the initial stiffness of joint in steel structures. In this study, an analytical component model for determining the column face stiffness of square or rectangular hollow section (SHS/RHS) subjected to tension was established, focusing on endplate connections. Equations for calculating the stiffness of the SHS/RHS column face in bending were derived through regression analysis using numerical results obtained from a finite element model database. Because the presence of bolt holes decreased the bending stiffness of the column face, this effect was calculated using a novel plate-spring-based model through numerical analysis. The developed component model was first applied to predict the bending stiffness of the SHS column face determined through tests. Furthermore, this model was incorporated into the component-based method with other effective components, e.g., bolts under tension, to determine the tensile stiffness of the T-stub connections, which connects the SHS column, and the initial rotational stiffness of the joints. A comparison between the model predictions, test data, and numerical results confirms that the proposed model shows satisfactory accuracy in evaluating the bending stiffness of SHS column faces.

• Nuclear Engineering and Technology
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• 제55권4호
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• pp.1571-1584
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• 2023

In this study, a numerical analysis was performed as part of an international joint research project to reproduce a real cable tray fire that occurred in the heater bay area of the turbine building of a nuclear power plant. A sensitivity analysis was performed on various input parameters to derive results consistent with the sprinkler activation time obtained from the fire event analysis. For all sensitive parameters, the normalized sprinkler activation time correlated well with the power function of the normalized sprinkler height. A correlation equation was developed to identify the sprinkler activation time at any location when determining the slope or fire growth rate under the conditions assuming a linear or t-squared heat release rate (HRR) time curve. Various cable fire growth assumptions were used to determine which assumption was better to provide the prediction coincident with the information given from the fire event analysis in terms of the sprinkler activation time and total energy generated from cables damaged by fire. In the comprehensive analysis of all the sensitive parameters, the standard deviation of the input parameters increased as the sprinkler height decreased. Within the range of the sensitivity parameter values given in this study, when considering all sprinkler heights, the standard deviation of the cable model change was the largest and that of the overhang position change was the smallest.

• 대한골관절종양학회지
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• 제10권2호
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• pp.79-87
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• 2004

목적: 최근 자기공명영상의 개발로 다양한 연조직종양의 영상의학적 진단이 가능해 졌다. 그러나 연조직종양의 다양한 조직구성이나 시간에 따라 구성분의 변화는 자기공명영상 만으로 악성과 양성 종양조차 감별을 어렵게 한다. 이에 본 저자들은 임상과 자기공명영상의 복합적인 소견으로 악성과 양성 연조직종양을 감별해 보고자 하였다. 대상 및 방법: 병리조직학적으로 확진된 82례(중간성종양을 악성종양으로 포함하여 37례와 염증성 종괴를 양성종양으로 포함하여 45례)를 후향적으로, 임상적 소견으로 연령, 크기, 위치, 그리고 자기공명영상 소견으로 종양경계, T2신호강도양상, 조영제T1신호강도양상, 그리고 조영증강 범위를 연관시켜 분석하였다. 자기공명영상으로 진단이 어렵지 않는 많은 전형적인 지방종과 결절종 그리고 농양같은 낭종은 양성종양 분류에서 제외하였다. 결과: 악성연조직종양은 양성에 비하여 연령으로 21~40세와 61~80세, 크기로 3.0 cm 이상, 발생위치로 몸체-골반-하지, 그리고 자기공명영상에서 불규칙한 경계, 50%이상의 조영증강범위 소견들의 빈도가 높았다. 결론: 발생위치로 몸체-골반-하지 와 상지-어깨-척추 로 나눈 임상소견이 악성과 양성 연조직종양을 감별하는데 통계학적으로 유의성있는 차이를 보였으며 나머지 다른 소견들은 특이적이지는 않았지만 부가적으로 악성과 양성을 감별하는데 도움이 되는 소견이었다.

• 한국운동역학회지
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• 제22권2호
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• pp.201-208
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• 2012

The purpose of this study was to investigate the effect of leg extension exercises performed on outdoor resistance exercise machines on knee extension muscle strength and quadriceps muscle group cross sectional area (CSA) in elderly women. Two groups were recruited for this study, including an exercise group (EG: n=13, $71.38{\pm}2.79$ yrs) and a control group (CG: n=5, $73.4{\pm}5.94$), In all subjects, maximum isometric and isokinetic muscle strength of knee flexion and extension were measured using an isokinetic dynamometer (Cybex(R) Humac Norm Testing & Rehabilitation System, USA). Quadriceps muscle group CSA were measured using MRI (Philps, Intera 1.5 T, NE Netherlands). The results of this study showed that post-intervention isometric knee extension peak torque value were higher than pre-intervention measures in the EG. However, the EG did not show improvement in quadriceps muscle group CSA, Also, no differences in the shift of optimal knee joint angle were observed between pre and post-intervention exercise. Outdoor leg extension exercise showed small increases in muscle strength in comparison to other resistance training exercises. The results of this study suggest that because outdoor leg extension exercise machines lack a progressive loading mechanism, significant increases in muscle strength may not be obtained.

• 한국강구조학회 논문집
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• 제10권4호통권37호
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• pp.709-720
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• 1998

용접잔류응력의 모재두께방향을 포함하는 3차원 분포를 파악하기 위해, 용접상세를 변화시킨 필렛용접이음을 대상으로 해서 실험 및 해석을 수행하였다. 특히, 지금까지 계측이 곤란했던 필렛용접이음의 용접루트부의 잔류응력을 실측하였다. 파라메타로써는 용접입열량과 용접층수를 취급하고, 모재두께방향을 포함하는 3차원 잔류응력의 분포를 조사하였다. 그 결과, 입열량이 증가하면, 용접토우와 루트부를 포함하는 용접부에서는 잔류응력의 크기에 변화가 거의 없지만, 인장잔류응력의 영역이 크게 나타났다. 또 단층과 다층용접의 비교에서는, 다층용접 쪽이 단층용접보다 잔류응력이 상당히 낮음을 알 수 있었다. 용접부 근방의 인장잔류응력의 영역도 다층용접 쪽이 단층용접보다 작게 나타난 것을 알 수 있었다.

• 근관절건강학회지
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• 제4권1호
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• pp.48-60
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• 1997

This study was undertaken to identify the musculotendinous problems and contributing factors to those problems In students majoring in musical instruments in Korea. The data were collected from March 2, 1996 to March 31, 1996 from 261 music students in various geographical areas. The data were analyzed for descriptive statistics, t-test, chi-square using SPSS $PC^+$ program. The results of this study were as follows : 1. In a questionnaire survey of 261 music students, one hundred twenty five(47.9%) reported having had various musculotendinous symptoms. Twenty seven students among the those who had previous symptoms(21.9%) reported the present symptoms. 2. The experience rates of musculotendinous problems in keyboard players, string players and woodwind players were 50.3%, 48.2%, 33.3% respectively. 3. Most of the students practiced most intensively during their high school years and the musculotendinous symptoms began at the same period. 4. Pain, tenderness and stiffness were the most common symptoms, while paresthesia and motor dysfunction were rare. This indicates that most players had muscle tendinous overuse, while small number had nerve entrapment and motor dysfunction. 5. In past and present symptoms, string players experienced musculotendinous symptoms mainly in both sides of shoulders, lumbar area, left finger, and left wrist, while keyboard players experienced more symptoms in the right wrist, shoulder, fingers than left side. 6. The major contributing factors to the symptoms were weight of instrument, types of instruments, types of daily activities, duration of practice, and playing technique. 7 The most frequent treatment modalities for the symptoms were acupuncture or moxibustion, other alternative therapy such as heat compress and massage. Through this study it was found that the musculotendinous problems might be increased along with their career, due to lack of knowledge about preventive measures and patterns of health behavior seeking alternative modalities rather than professional consultation. Therefore, preventive measures that focus on playing habits such as duration of practice, frequency of rest and position while playing should be developed and taught to the students, their parents, and music educators. Doctors who are interested in this area should attempt to correct the position and posture while playing of the posture. And measures for reduction of loading of instrument weight should also be developed.

• 대한방사선기술학회지:방사선기술과학
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• 제29권3호
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• pp.157-165
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• 2006

자기공명영상에 의해 진단된 척추질환에 대하여 성별 및 나이별 발생빈도, 발생부위 등 임상적 특성을 분석하여 임상에서 참고 자료로 활용할 수 있도록 하였다. 수도권 소재의 B대학병원에서 2004년 1월부터 12월까지 척추 자기공명영상 검사를 하여 척추질환 유소견자로 진단된 총 1,291명을 대상으로 하였고, 수집된 자료는 SPSS WIN 11.5 프로그램을 이용하여 분석하였으며, 그 결과는 다음과 같다. 1. 연구의 조사대상자에 대한 일반적 특성은 총 1,291명 중 남자가 53.5%, 여자 46.5%이었다. 2. 척추질환의 부위별 발생빈도는 요추 65.6%, 경추 27.3%, 흉추 7.0% 순으로 나타났다. 3. 척추질환의 빈도가 높은 상위 10개 질환은 다음과 같다. 1) posterior bulging disc 65.8%. 2) narrowing of neural foramen 23.8% 3) herniated intervertebral disc (HIVD) 22.4% 4) spinal stenosis 16.7% 5) osteochondrosis 6.4% 6) compression fracture 6.4% 7) facet joint arthropathy 6.2% 8) spondylolisthesis 6.0% 9) spinal cord tumor 3.5% 10) inter body fusion 2.6%

• 근관절건강학회지
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• 제17권1호
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• pp.14-24
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• 2010

Purpose: The purpose of this study was to investigate the effect of ear reflexotherapy on back pain of working women in middle age. Methods: The quasi-experimental, nonequivalent control group pretest-posttest design was used for the study. Total of 56 participants composed of experimental group (n=26) and control group (n=30), who were working in four hospitals in urban area. The degree of back pain after ear reflexotherapy was measured by VAS. The data were analyzed by frequency, percent, t-test and $X^2$-test. Results: The degree of back pain after ear reflexotherapy in the experimental group was significantly reduced, while there was no difference in control group. There was a significant difference between the experimental group and control group in the degree of back pain after ear reflexotherapy (t=3.702, p=.001). Conclusion: Application of ear reflexotherapy was effective for employed women in middle age and it needs to be further evaluated among the other population.

• 근관절건강학회지
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• 제17권2호
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• pp.203-211
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• 2010

Purpose: We aimed to test the validity of the EQ-5D (Euro-Quality of Life-5 Dimension), a brief and simple instrument, in measuring health related quality of life in the patients with osteoarthritis. Methods: 183 participants attending the education programs for osteoarthritis patients at the Health Centers located in Seoul and Gyunggi province area during the periods of June to December in 2009 were interviewed with the EQ-5D and KWOMAC (Korean version of Western Ontario and McMaster Scale). The data were analysed with Spearman correlation coefficents and t-test by using of SPSS/WIN 12.0 version. Results: There was a negative correlation between knee pain, stiffness and difficulty in usual activity of sub category items of KWOMAC and EQ-5Dindex, while there was no correlation between these categories and EQ-VAS. Moreover, as a result of comparing the score of physical function measured by KWOMAC according to the severity degree of the EQ-5Dindex, the group of advanced stage having moderate and severe symptoms reported significantly higher scores of physical function than those of groups having no health problems. Conclusion: The EQ-5D is an acceptable and valid instrument for measuring health-related quality of life in patients with osteoarthritis.

• Nutrition Research and Practice
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• 제16권5호
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• pp.589-603
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• 2022

BACKGROUND/OBJECTIVES: Previous studies have reported that protein supplementation contributes to the attenuation of inflammation. Serious trauma such as burn injury usually results in the excessive release of inflammatory factors and organs dysfunction. However, a few reports continued to focus on the function of protein ingestion in regulating burn-induced inflammation and organ dysfunction. MATERIALS/METHODS: This study established the rat model of 30% total body surface area burn injury, and evaluated the function of blended protein (mixture of whey and soybean proteins). Blood routine examination, inflammatory factors, blood biochemistry, and immunohistochemical assays were employed to analyze the samples from different treatment groups. RESULTS: Our results indicated a decrease in the numbers of white blood cells, monocytes, and neutrophils in the burn injury group administered with the blended protein nutritional support (Burn+BP), as compared to the burn injury group administered normal saline supplementation (Burn+S). Expressions of the pro-inflammatory factors (tumor necrosis factor-α and interleukin-6 [IL-6]) and chemokines (macrophage chemoattractant protein-1, regulated upon activation normal T cell expressed and secreted factor, and C-C motif chemokine 11) were dramatically decreased, whereas anti-inflammatory factors (IL-4, IL-10, and IL-13) were significantly increased in the Burn+BP group. Kidney function related markers blood urea nitrogen and serum creatinine, and the liver function related markers alanine transaminase, aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase were remarkably reduced, whereas albumin levels were elevated in the Burn+BP group as compared to levels obtained in the Burn+S group. Furthermore, inflammatory cells infiltration of the kidney and liver was also attenuated after burn injury administered with blended protein supplementation. CONCLUSIONS: In summary, nutritional support with blended proteins dramatically attenuates the burn-induced inflammatory reaction and protects organ functions. We believe this is a new insight into a potential therapeutic strategy for nutritional support of burn patients.