• Asian Pacific Journal of Cancer Prevention
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• 제15권2호
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• pp.737-741
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• 2014

Background: In recent years a wide variety of flavonoids or polyphenolic substances have been reported to possess substantial anti-carcinogenic and antimutagenic activities. Grape proanthocyanidins (GPC) are considered as good examples for which there is evidence of potential roles as anti-carcinogenic agents. Methods: A xenograft model was established using H22 cells subcutaneously injected into mice and used to assess different concentrations of grape proanthocyanidins (GPC) and Endostar. Treatments were maintained for 10 days, then levels of vascular endothelial growth factor (VEGF) and microvessel density (MVD) were examined by immunohistochemistry, while VEGF mRNA was determined by real-time PCR in tumor tissue. Results: The expression of MVD and VEGF decreased gradually as the concentration of GPC increased.There was a significant positive correlation between MVD and VEGF. Conclusions: These results suggest that GPC restrains the growth of tumor, possibly by inhibiting tumour angiogenesis.

• 한국구조물진단유지관리공학회 논문집
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• 제7권2호
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• pp.159-167
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• 2003

Cracks in reinforced concrete structures reduce overall durability by allowing the penetration of water and aggressive agents, thereby accelerating the deterioration of the reinforcing steel. Highway pavement and bridge decks are especially susceptible to this type of deterioration since these structures exhibit high rates of shrinkage and are frequently exposed to aggressive environmental conditions. The objectives of this investigation included the development of experimental procedures for assessing shrinkage cracking potential of recycled aggregate concrete, the evaluation of mix composition on shrinkage cracking potential, and the development of theoretical models to simulate early-age cracking behavior. Specifically, the influences of shrinkage-reducing admixture(SRA) and recycled aggregate concrete were investigated. The shrinkage-reducing admixture substantially reduces free shrinkage and restrains shrinkage cracking while providing similar mechanical properties. A fracture mechanics modeling approach was developed to predict the behavior of a variety of restrained concrete specimens. This modeling approach was used to successfully explain experimental results from a variety of mixture compositions. The model was used to demonstrate the influence of material and structural properties on the potential for cracking.

• 한국구조물진단유지관리공학회 논문집
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• 제21권4호
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• pp.116-123
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• 2017

본 연구는 음의 포아송비 거동을 가지는 격자체의 구조부재 보강재로의 적용이 가능한지에 대한 검토를 수행하였다. 콘크리트를 포함한 일반적인 재료는 외부 하중의 작용 시 양의 포아송비 거동을 가진다. 이러한 콘크리트의 역학적 거동을 음의 포아송비 특성을 가지는 금속 격자체가 구속함으로써 콘크리트의 강성을 증대시킬 수 있음을 이론적으로 확인하였다. 또한 실제 건설산업에 적용이 가능한 수준의 음의 포아송비 거동을 가지는 격자체의 형식을 제시, 역학적 거동 특성을 수치 해석적으로 검토하였다.

• 대한예방한의학회지
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• 제17권1호
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• pp.65-76
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• 2013

Objectives : Aim of this study is to contribute to establishment of the Traditional Korean Medicine (TKM) policies in the future. Final assessment for 12 of the forecasting projects was carried out on the TKM policies that deduced by professionals in 1996 whether or not to realize in 2013. Methods : We investigated governmental and private research projects, reports and papers, and laws and systems on the forecasting projects. We reviewed them through the Traditional Korean Medicine Information Portal OASIS (http://oasis.kiom.re.kr), Korean studies Information Service System (KISS) (http://kiss.kstudy.com/) and DBpia (http://www.dbpia.co.kr/), Akomnews(http://www.akomnews.com/), THE MINJOK MEDICINE NEWS(http://www.mjmedi.com/), Ministry of Government Legislation(http://www.law.go.kr/). Results : Of the 12 forecasting projects, five were judged as 'realization', four were as 'partial realization' and three were as 'un-realization', The realization rate was 75.0%. Three un-realized projects included the TKM insurance coverage for various herbal medicines, leadership secure on medical technicians and commercialization of the TKM managing system on senior medicare policy. Realization of the future forecasting TKM policy projects was decided depending on conditions such as the importance, domestic capability levels, principal agents, methods and restrains. Conclusions : Continuous studies and new developed forecasting projects for the TKM policies will be required to realize the projects in the future.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.283-283
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• 2010

The liquid metal ion sources(LMIS) in FIB system have many advantages of high current density, high brightness and low ion energy spread. Most FIB systems use LMIS because the ion beam spot size of LMIS is smaller than other ion sources. LMIS is basically emitted by an extractor but the new electrode called the suppressor is able to control the emission current. We investigated characteristics LMIS with a suppressor, the function of the suppressor in LMIS, the change of the electric field by the suppressor and the advantages of using the suppressor. The characteristics of the threshold voltage and current-voltage (I-V) were observed under the varying extracting voltage with floated suppressor voltage, and under the varying suppressor voltages with fixed extractor voltage. We also simulated LMIS with the suppressor through CST(Computer Simulation Technology). The emission current increases as the suppressor voltage decreases because the suppressor voltage which restrains the electric field goes down, The threshold voltage increases as the suppressor voltage increases. We can explain characteristics and functions of LMIS with a suppressor using the electric field.

• 한국간호교육학회지
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• 제7권2호
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• pp.379-390
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• 2001

The purpose of this study was to examine the actual condition of the adolescent status delinquency and to predict that family environments, the mother's rear attitudes and personal factors influence on the adolescent status delinquency among high school students in Busan(N=404). Under these purposes of the study, the preliminary study was performed to divided the criminal delinquency from the status delinquency, and on the basis of the result of the preliminary study, the analysis of causal pathway were performed. The data were surveyed using paper and pencil self-rating. Descriptive statistics and pathway analyses were conducted to answer research objectives. The result of this study was as follows. First, the status delinquency and the criminal delinquency are different dimensions with each other independently. Second, Contents of the status delinquencies were Drinking, Smoking, Cheating examination, Stopping out, Reckless running, Gang fighting, Reading lewdness and Watching lewd video, Sexual intercourse with the other gender, etc., The criminal delinquencies were Robbing of bicycle or auto-bicycle, Taking nalcotic drug, Robbing money of drunkard and women, Rape, Setting on fire, etc. Third, The factors of structural environments of the family and the factors of mother's rear attitude influenced on the status delinquency via adolescence's compulsivity. that is to say, if the mother's rear attitude is affective, it restrains the impulsivity of adolescence causing to the restraint of the status delinquency.

• 한국추진공학회지
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• 제15권4호
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• pp.48-56
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• 2011

직경 대 길이비(L/D)의 값이 큰 고체 추진기관에서는 축방향 연소불안정 현상이 발생할 가능성이 높다. 일반적으로 이러한 현상을 억제하기 위해 추진제에 금속입자를 포함시키거나 그레인 설계시 축방향 압력 진동을 억제할 수 있도록 형상을 고안한다. Slotted-Tube형 그레인을 적용한 고체 추진기관은 연소시 Slot의 영향으로 인해 축방향 1차 모드 압력진동이 억제되나 연소관 후방 내열재 삭마로 인해 공동이 형성되어 Vortex Shedding에 의한 2차 모드 압력진동이 증폭될 수 있다. 본 연구에서는 4 Slotted Tube형 고체 추진기관의 설계 개선을 통해 Vortex Shedding을 억제하여 연소불안정 현상을 개선하였다.

• 정보관리연구
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• 제38권2호
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• pp.127-152
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• 2007

오늘날 아동은 성인보다 컴퓨터와 인터넷을 통한 정보습득에 익숙하며 실제로 그들의 생활형태에 커다란 영향을 미치고 있다. 이에 공공도서관은 시공간에 제약 없이 아동들이 스스로 평생동안 학습하고, 책을 읽고, 정보에 접근할 수 있도록 웹사이트를 구축하여 제공해야 한다. 본 연구는 공공도서관 웹사이트의 중요성, 특히 아동을 위한 공공도서관 웹서비스의 중요성과 국내 동향을 분석하고 개선방안을 제시하고자 하는데 목적이 있다. 이를 위하여 대구 경북지역의 공공도서관 홈페이지를 대상으로 웹사이트의 구축여부, 구성체계, 검색서비스, 콘텐트를 분석하였다.

• Steel and Composite Structures
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• 제10권4호
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• pp.361-371
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• 2010

Enhancement in the seismic buckling capacity of steel tanks caused by the addition of fiber reinforced polymers (FRP) retrofit layers attached to the outer walls of the steel tank is investigated. Three-dimensional non-linear finite element modeling is utilized to perform such analysis considering non linear material properties and non-linear large deformation large strain analysis. FRP composites which possess high stiffness and high failure strength are used to reduce the steel hoop stress and consequently improve the tank capacity. A number of tanks with varying dimensions and shell thicknesses are examined using FRP composites added in symmetric layers attached to the outer surface of the steel shell. The FRP shows its effectiveness in carrying part of the hoop stresses along with the steel before steel yielding. Following steel yielding, the FRP restrains the outward bulging of the tank and continues to resist higher hoop stresses. The percentage improvement in the ultimate base moment capacity of the tank due to the addition of more FRP layers is shown to be as high as 60% for some tanks. The percentage of increase in the tank moment capacity is shown to be dependent on the ratio of the shell thickness to the tank radius (t/R). Finally a new methodology has been explained to calculate the location of Elephant foot buckling and consequently the best location of FRP application.

• 대한조선학회논문집
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• 제47권6호
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• pp.770-775
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• 2010

As considerable interests in noise emission from the ships have been increased, control of the propeller cavitation generating vibration and radiating noise is looming large. In general, the tip vortex cavitation is first produced in case of full scale propellers, and noise levels rise dramatically from that moment. In order to reduce induced noise from the tip vortex cavitation and hence increase the cavity inception speed, we propose the mass injection method. Water injected from the propeller tip decreases rotating speed of the tip flow, and it restrains growing the tip vortex cavity. Experimental investigations of the model tests carried out in a large cavitation tunnel show that the tip vortex cavitation is effectively controled by water injection from the propeller tip.