• Nuclear Engineering and Technology
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• 제48권3호
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• pp.785-794
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• 2016

The Argonne National Laboratory of the United States and the Kharkov Institute of Physics and Technology of the Ukraine have been collaborating on the design, development and construction of a neutron source facility at Kharkov Institute of Physics and Technology utilizing an electron-accelerator-driven subcritical assembly. The electron beam power is 100 kW using 100-MeV electrons. The facility was designed to perform basic and applied nuclear research, produce medical isotopes, and train nuclear specialists. The biological shield of the accelerator building was designed to reduce the biological dose to less than 5.0e-03 mSv/h during operation. The main source of the biological dose for the accelerator building is the photons and neutrons generated from different interactions of leaked electrons from the electron gun and the accelerator sections with the surrounding components and materials. The Monte Carlo N-particle extended code (MCNPX) was used for the shielding calculations because of its capability to perform electron-, photon-, and neutron-coupled transport simulations. The photon dose was tallied using the MCNPX calculation, starting with the leaked electrons. However, it is difficult to accurately tally the neutron dose directly from the leaked electrons. The neutron yield per electron from the interactions with the surrounding components is very small, ~0.01 neutron for 100-MeV electron and even smaller for lower-energy electrons. This causes difficulties for the Monte Carlo analyses and consumes tremendous computation resources for tallying the neutron dose outside the shield boundary with an acceptable accuracy. To avoid these difficulties, the SOURCE and TALLYX user subroutines of MCNPX were utilized for this study. The generated neutrons were banked, together with all related parameters, for a subsequent MCNPX calculation to obtain the neutron dose. The weight windows variance reduction technique was also utilized for both neutron and photon dose calculations. Two shielding materials, heavy concrete and ordinary concrete, were considered for the shield design. The main goal is to maintain the total dose outside the shield boundary less than 5.0e-03 mSv/h during operation. The shield configuration and parameters of the accelerator building were determined and are presented in this paper.

• 한국치위생학회지
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• 제9권4호
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• pp.874-884
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• 2009

Objectives : This study was to investigate the level of oral health concern and the purchase behavior of environmental friendly agricultural products and to determine the relationship between oral health concern and the purchase behavior of environmental friendly agricultural products. Methods : The subjects were 99 male(29.7%) and 234 female(70.3%), who were over 20 years with mean age of 39.6 years. The data was collected using personal interviews and a self administrated questionnaire from August 1 to September 30, 2008. Oral health concern was measured using the 7-items, and the purchase behavior of environmental friendly agricultural products was measured using the 7-items. The data were analysed with t-test, one-way ANOVA and multiple logistic regression using the SPSS 15.0 windows. Results : Regarding oral health concern, the subjects was a mean of 2.86 out of a maximum 5 points. There were differences in the level of oral health concern according to the purchase behavior of environmental friendly agricultural products(experience, period, frequency, price, weight). Conclusions : These results suggest that the strategies of habitual use environmental friendly agricultural products to put in practice oral health promoting behavior is needed to improve quality of life in people.

• 대한지역사회영양학회지
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• 제6권5호
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• pp.819-829
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• 2001

The purpose of this study was to investigate the difference of general characteristics, menopause status, dietary patterns and nutrient intakes between women aged from 30 to 65 years old with a hypercholesterolemia group and normocholesterolemia group. The subjects were classified as belonging to the hypercholesterolemia group or normocholesterolemia group barred on The Guidelines for Korean Hyperlipidemia. Dietary intakes of fatty acids were measured by means of a 24-hr recall method with food models and measuring tools. We analyzed both data sets together using analysis of variance chi-square test and student's t-test(SPSS for WINDOWS, version 7.5). Significance was defied as a p value < 0.05. The results obtained are summarized as follows. Mean age and BMI of the hypercholesteroemia group were significantly higher than those of the normocholesterolemia group. Intakes of cereal, vegetables, mushrooms and sea food in the normocholesterolemia group were significantly higher than those in the hypercholesterolemia group. Most of the nutrient intakes were not significantly different between the normocholesterolemia group and the hypercholesterolemia group. However, vitamin E intake of the normocholesterolemia group was significantly higher than that of the hypercholesterolemia group. There was a significant negative correlation between vitamin E intake and serum TC(r = -.363, p < 0.001) and LDL-C(r = -.359, p < 0.001). In addition, Serum TG had significantly correlation with carbohydrate(r = 0.137, p < 0.001) and vitamin E intake(r = -0.134, p < 0.001). Therefore, women who suffered from hypercholesterolemia were recommended to control body weight, and to consume foods containing high vitamin E and foods containing high dietary fiber such as vegetables, mushrooms, and sea food.

• The Journal of Advanced Prosthodontics
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• 제5권2호
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• pp.110-117
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• 2013

PURPOSE. Polymethyl methacrylate (PMMA) is the most commonly used denture base material despite typically low in strength. The purpose of this study was to improve the physical properties of the PMMA based denture base resins (QC-20, Dentsply Ltd., Addlestone, UK; Stellon, AD International Ltd, Dentsply, Switzerland; Acron MC; GC Lab Technologies Inc., Alsip, Japan) by copolymerization mechanism. MATERIALS AND METHODS. Control group specimens were prepared according to the manufacturer recommendations. In the copolymer groups; resins were prepared with 5%, 10%, 15% and 20% acrylamide (AAm) (Merck, Hohenbrunn, Germany) content according to the moleculer weight ratio, respectively. Chemical structure was characterized by a Bruker Vertex-70 Fourier transform infrared spectroscopy (FTIR) (Bruker Optics Inc., Ettlingen, Germany). Hardness was determined using an universal hardness tester (Struers Duramin, Struers A/S, Ballerup, Denmark) equipped with a Vickers diamond penetrator. The glass transition temperature ($T_g$) of control and copolymers were evaluated by Perkin Elmer Diamond DSC (Perkin Elmer, Massachusetts,USA). Statistical analyses were carried out using the statistical package SPSS for Windows, version 15.0 (SPSS, Chicago, IL, USA). The results were tested regarding the normality of distribution with the Shapiro Wilk test. Data were analyzed using ANOVA with post-hoc Tukey test (P<.01). RESULTS. The copolymer synthesis was confirmed by FTIR spectroscopy. Glass transition temperature of the copolymer groups were higher than the control groups of the resins. The 10%, 15% and 20% copolymer groups of Stellon presented significantly higher than the control group in terms of hardness. 15% and 20% copolymer groups of Acron MC showed significantly higher hardness values when compared to the control group of the resin. Acrylamide addition did not affect the hardness of the QC-20 resin significantly. CONCLUSION. Within the limitation of this study, it can be concluded that copolymerization of PMMA with AAm increased the hardness value and glass transition temperature of PMMA denture base resins.

• 한국산학기술학회논문지
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• 제18권8호
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• pp.344-349
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• 2017

최근 전 세계적으로 고층건물의 외벽청소, 대형 구조물의 벽면검사, 조선에서의 벽면 용접 등 다양한 용도의 벽면이동 로봇들이 개발되고 있다. 기존에 개발된 벽면이동 로봇 중 바퀴형 이동로봇은 요철이 있는 벽면을 이동할 수 없다는 단점이 있으며 보행형 이동로봇은 복잡한 링크구조로 인해 많은 액추에이터가 필요로 하고, 더불어 제어가 복잡해지며 내구성의 문제가 발생한다. 또한 로봇의 무게가 무겁다는 단점이 있다. 본 논문에서는 이러한 단점을 극복하기 위해 간단한 구조를 가진 새로운 벽면이동 로봇을 제시한다. 본 논문의 벽면이동 로봇은 단 한 쌍의 축과 액추에이터를 이용하여 고릴라의 보행방식을 모사하여 이동하며, 진공펌프와 흡착패드를 이용하여 벽면에 진공 흡착한다. 본 논문에서 개발한 로봇의 구성요소로는 이동을 위한 DC모터, 흡착을 위한 진공펌프, 제어를 위한 마이크로 컨트롤러, 기타 동력전달과 형체 유지를 위한 축과 프레임이 있다. 로봇의 성능은 수직 및 수평에서 실험적으로 검증하였다. 본 논문에서 개발한 벽면이동 로봇을 기반으로 다양한 장치를 탑재한 산업현장, 재난재해 현장에서 다양한 기능을 수행하는 로봇의 개발이 가능할 것이라 전망한다.

• 대한한방부인과학회지
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• 제25권2호
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• pp.174-184
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• 2012

Objectives: The purpose of this study was to observe the early postpartum low back pain and pelvic girdle pain in the Korean medical hospital for 2-weeks. Methods: Fifty-one postpartum women who admitted for postpartum care in Korean hospital from December 3rd, 2011 to January 31st, 2012 had written out pain measurement questionnaires(SF-MPQ, VAS, ODI) three times for 2-weeks. SPSS 18.0 for Windows was used to analyse the data and the independent samples t-test, paired T-test were used to verify the results. Results: 1. Evaluation of low back pain within the first week after birth was as follows: SF-MPQ sensory area was $5.06{\pm}4.41$ points; SF-MPQ emotional areas was $0.86{\pm}1.34$ points; VAS mean was $3.79{\pm}2.02$ points; and ODI mean was $10.27{\pm}6.69$. 2. Early postpartum low back pain and pelvic girdle pain were significantly decreased in SF-MPQ, VAS, and ODI after 2-weeks(p < 0.01). 3. Age, birth type, parity, weight, and BMI increased during pregnancy does not affect the postpartum low back pain and pelvic girdle pain. Conclusions: The top 10% of postpartum low back pain scale was 10.8 points or more in the sensory area of SF-MPQ, and 3 points or more in the affective area of SF-MPQ. In the case of VAS, it was more than 7 points, and ODI was more than 21.8 points. Postpartum back pain with oriental medical treatment was significantly improved.

• Nuclear Engineering and Technology
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• 제50권6호
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• pp.989-995
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• 2018

Argonne National Laboratory of the United States and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have cooperated on the development, design, and construction of a neutron source facility. The facility was constructed at Kharkov, Ukraine, and its commissioning process is underway. The facility will be used for researches, producing medical isotopes, and training young nuclear specialists. The neutron source facility is designed with a provision to include a cryogenically cooled moderator system-a cold neutron source (CNS). This CNS provides low-energy neutrons, which will be used in the scattering experiment and material structures analysis. Cold neutron guides, coated with reflective material for the low-energy neutrons, will be used to transport the cold neutrons to the experimental site. The cold neutron guides would keep the cold neutrons within certain energy and angular space concentrated inside, while most of the gamma rays and high-energy neutrons are not affected by the cold neutron guides. For the KIPT design, the cold neutron guides need to extend several meters outside the main shield of the facility, and curved guides will also be used to remove the gamma and high-energy neutron. The neutron guides should be installed inside a shield structure to ensure an acceptable biological dose in the facility hall. Heavy concrete is the selected shielding material because of its acceptable performance and cost. Shield design analysis was carried out for the CNS guide hall. MCNPX was used as the major computation tool for the design analysis, with neutron and gamma dose calculated separately. Weight windows variance reduction technique was also used in the shield design. The goal of the shield design is to keep the total radiation dose below the $5.0{\mu}Sv/hr$ guideline outside the shield boundary. After a series of iterative MCNPX calculations, the shield configuration and parameters of CNS guide hall were determined and presented in this article.

• 한국운동역학회지
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• 제28권4호
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• pp.227-236
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• 2018

Objective: The purpose of this study was to investigate the effects of a 12-week combined exercise program on gait parameters in elderly women with osteoarthritis. Method: The subjects of this study were 11 elderly women (age: $67.09{\pm}2.47$, height: $157.35{\pm}4.30cm$, weight: $62.49{\pm}6.36kg$) with knee osteoarthritis. The combined exercise program of this study was divided into aerobic exercise and lower extremity strengthening exercises. The exercises were performed for 60 minutes per session, three times a week, for a total of 12 weeks. The maximum joint moments of the hip, knee, and ankle joints with walking were obtained with 8-3D cameras (MX-T20, Vicon, USA) and 2-force plate (AMTI OR6-7-400, AMTI, USA). SPSS Windows version 23.0 was used for statistical analysis. A paired t-test was used for pre-post comparison. An alpha level of .05 was utilized in all tests. Results: The maximum extension moment was significantly higher in the hip joint after P1 on the X axis. The maximum joint moment of P3 in extension was statistically significantly lower after intervention. On the Z axis, the maximum joint moment was significantly lower after the exercise intervention at P3. There was a statistically significant increase in the extension moment of the left and right knee joints in the X axis after exercise intervention. In the right ankle joint, P1 (plantar flexion moment) showed a statistically significant high moment after exercise intervention. Conclusion: These results suggest that combined exercise, including lower limb and aerobic exercise, may have a positive effect on mobility and walking moments in patients with osteoarthritis of the knee.

• 방송공학회논문지
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• 제27권4호
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• pp.538-547
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• 2022

최근 소개된 트랜스포머(Transformer)를 이용한 이미지 분류 방법들은 기존 합성곱 신경망 기반 방법 대비 괄목할 만한 성능 향상을 보여주고 있다. 지역적 특성을 효과적으로 고려하기 위해 이미지 영역을 복수의 윈도우 영역으로 나누어 트랜스포머를 적용하는 방법에 대한 연구가 활발히 진행되어 왔으나, 윈도우 간 관계 및 중요도에 대한 학습은 여전히 부족한 상황이다. 본 논문에서는 이러한 문제점을 극복하기 위해 각 윈도우의 중요도를 학습에 반영할 수 있는 트랜스포머 구조를 제안한다. 제안하는 방법은 각 윈도우 영역에 대한 자기주의(Self-attention) 연산을 기반으로 압축과 완전 연결 계층(Fully Connected Layer)을 통해 각 윈도우 영역의 중요도를 계산한다. 계산된 중요도는 윈도우 영역들 간의 관계를 학습한 가중치로써 각 윈도우 영역에 곱해져 특징 값을 재조정 한다. 실험 결과를 통해 제안하는 방법이 기존 트랜스포머 기반 방법의 성능을 효과적으로 향상 시킬 수 있음을 보인다.

• 대한방사선기술학회지:방사선기술과학
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• 제38권3호
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• pp.267-276
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• 2015

최근, 초음파검사로 인해 악성잠재력을 지닌 담낭용종의 발견률이 높아지고 있다. 담낭용종의 위험인자에 대한 다양한 연구가 보고 되었지만 혈청 생화학, 생활습관을 포함한 대사증후군과 담낭용종과의 관계에 대한 연구는 미흡한 실정이다. 본 연구의 목적은 한국에서의 생활습관, 생화학적 혈액검사를 포함한 대사성증후군과 담낭용종인 자간의 상관관계를 알아보는데 있다. 2012년11월2일부터 2014년1월31일까지 경기도내 2차병원을 방문한 151명 남성과 167명 여성을 대상으로 검사를 실행하였다. 이들은 무작위로 차출되었고, 담낭용종 유무에 따른 다양한 변수를 비교하였으며, 수집된 데이터는 Windows 프로그램 SPSS version 20.0을 사용하여 분석하였다. 평균 담낭용종의 크기는 직경이 3.92mm이고 용종의 크기는 직경이 10mm 이하였다. 담낭용종이 발견된 사람은 총184명(57.9%), 그 중 대사성증후군 발견된 사람은 114명(26.4%)으로, 대사성증후군을 가진 사람들에게서 담낭용종의 발생률이 높아짐을 알 수 있었다. 담낭용종에 대한 위험요소에서 체중 1.061배, BMI에서 1.186배, 수축기혈압에서 1.060배, 이완기혈압에서 1.030배, 총콜레스테롤에서 1.009배, 대사성증후군에서 2.736배, 당뇨에서 1.011배, 적혈구침강속도ESR에서 1.064배 높음을 알 수 있었다. 담낭용종의 위험인자는 체중, BMI, 총콜레스테롤, 중성지방, 당뇨, 수축기혈압, 이완기혈압, 적혈구침강속도ESR, 그리고 대사성증후군임을 알 수 있었다. 이 연구는 담낭용종에 대한 연구의 중요한 연구 자료로 사용되고, 차후에 좀 더 대규모의 연구가 이루어져야 할 것이다.