• 한국공간구조학회논문집
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• 제6권1호
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• pp.55-63
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• 2006

본 논문은 콘크리트 충전 원형 및 각형 합성 강관을 기둥부재로서의 적합성 및 적용성을 위한 연구로 두개의 강관을 합성한 콘크리트 충전 강관 기둥의 축압축 좌굴내력 및 변형형상에 대한 실험적 연구이다. 강관 기둥에 대한 연구는 콘크리트 충전 원형 강관 기둥, 콘크리트 충전 각형 강관 기둥, 콘크리트 충전 합성 강관 기둥으로 분류하여 실험을 수행하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권9호
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• pp.3635-3638
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• 2015

Several improvements in ovarian cancer treatment have been achieved in recent years, both in surgery and in combination chemotherapy with targeting. However, ovarian tumors remain the women's cancers with highest mortality rates. In this scenario, a pivotal role has been endorsed to the immunological environment and to the immunological mechanisms involved in ovarian cancer behavior. Recent evidence suggests a loss of the critical balance between immune-activating and immune-suppressing mechanisms when oncogenesis and cancer progression occur. Ovarian cancer generates a mechanism to escape the immune system by producing a highly suppressive environment. Immune-activated tumor infiltrating lymphocytes (TILs) in ovarian tumor tissue testify that the immune system is the trigger in this neoplasm. The TIL mileau has been demonstrated to be associated with better prognosis, more chemosensitivity, and more cases of optimal residual tumor achieved during primary cytoreduction. Nowadays, scientists are focusing attention on new immunologically effective tumor biomarkers in order to optimize selection of patients for recruitment in clinical trials and to identify relationships of these biomarkers with responses to immunotherapeutics. Assessing this point of view, TILs might be considered as a potent predictive immunotherapy biomarker.

• 한국철도학회논문집
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• 제14권3호
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• pp.285-294
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• 2011

R&D 투자로 인한 기술의 축적, 경제적 성과 및 파급효과에 대한 분석이 거시적인 측면과 타 부문에서는 다양하게 이루어지고 있으나 철도산업에 대한 분석은 미흡한 실정이다. 본 연구에서 성과목표 설정에 대해서는 선행연구에 대한 조사분석을 통하여 과학기술적 성과에 대한 공통지표로 지식재산권, 특허, 논문을 설정하고 성공적으로 종료된 철도 R&D 11개 사업의 과학기술적 성과에 대한 적정성을 검증하였다. 선행연구에서 투입요소로 투자금액에 의한 성과목표를 설정하였으나 정확도를 향상시키기 위해 투입요소로, 투자금액(RI), 자본적 투자금액(RCI), 인당 내부인건비(LCPM)를 적용하였으며 철도 R&D 11개 사업에 대한 횡단면 분석과 잔차 분석을 통하여 성과목표 모형을 설정하고 타 과제 분석을 통하여 실증분석과 타당성을 검증하였다.

• 동력기계공학회지
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• 제12권4호
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• pp.5-11
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• 2008

The RI gasoline engine haying a sub-chamber had a high cycle variation due to the difficulty of the residual gas scavenge in the sub-chamber. To solve this problem and improve the combustion performance of RI engine, we devised a method to inject directly CNG fuel into the sub-chamber. A DI diesel engine of single cylinder was converted into a RI-CNG engine and an electronic control unit for the engine was manufactured. In this study, the combustion characteristics of the RI-CNG engine were investigated with the injection timings and air excess ratios at the load conditions of 50% throttle open rate and 1700rpm. As the results from this study, the RI-CNG engine worked reliably under the condition of the ignitable lean limit of $\lambda=1.7$ by showing the $COV_{imep}$ below about 5%. And the highest thermal efficiency could be obtained in the injection timing that produced the high imep and the low $COV_{imep}$ at the same time. The CO emission concentration indicated very low values and the THC and $NO_x$ showed an opposite pattern. With a view to improving the thermal efficiency and reducing the harmful emissions, the proper control region of the ignition timing and the mixture ratio were nearly ATDC $20^{\circ}\sim50^{\circ}$ and $\lambda=1.4$ respectively.

• Steel and Composite Structures
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• 제22권5호
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• pp.937-974
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• 2016

While extensive efforts have been made in the past to develop finite element models (FEMs) for concrete-filled steel tubular columns (CFSTCs), these models may not be suitable to be used in some cases, especially in view of the utilisation of high strength steel and high strength concrete. A method is presented herein to predict the complete stress-strain curve of concrete subjected to tri-axial compressive stresses caused by axial load coupled with lateral pressure due to the confinement action in square and rectangular CFSTCs with normal and high strength materials. To evaluate the lateral pressure exerted on the concrete in square and rectangular shaped columns, an accurately developed FEM which incorporates the effects of initial local imperfections and residual stresses using the commercial program ABAQUS is adopted. Subsequently, an extensive parametric study is conducted herein to propose an empirical equation for the maximum average lateral pressure, which depends on the material and geometric properties of the columns. The analysis parameters include the concrete compressive strength ($f^{\prime}_c=20-110N/mm^2$), steel yield strength ($f_y=220-850N/mm^2$), width-to-thickness (B/t) ratios in the range of 15-52, as well as the length-to-width (L/B) ratios in the range of 2-4. The predictions of the behaviour, ultimate axial strengths, and failure modes are compared with the available experimental results to verify the accuracy of the models developed. Furthermore, a design model is proposed for short square and rectangular CFSTCs. Additionally, comparisons with the prediction of axial load capacity by using the proposed design model, Australian Standard and Eurocode 4 code provisions for box composite columns are carried out.

• 한국산학기술학회논문지
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• 제8권3호
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• pp.488-495
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• 2007

일반용 전기설비의 정기적인 전기안전 점검과 부적합 설비의 개선조치에도 불구하고 전기화재의 80% 이상이 일반용 전기설비에서 발생하였으며 전기안전점검제도에 대한 이해부족, 미점검 수용가 증가, 누전차단기 미설치 및 부적합 시설의 방치 등의 원인으로 전기안전사고를 예방하는 것이 더욱 어려워진다. 본 논문에서는 일반용 전기설비의 전기안전점검 제도, 안전점검결과 및 전기화재 통계를 분석하천 관련 문제점을 도출하였다. 또한 전기안전점검제도, 점검업무 수행 방법, 전기화재 통계 수립 및 전기안전의식, 원격전기안전점검 체계 측면에서 일반용 전기설비 안전관리 개선방안을 제시하였다.

• 한국유기농업학회지
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• 제12권2호
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• pp.219-230
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• 2004

In recent years, the consumption of livestock products were markedly decreased by awareness of world-widely occurred diseases including mad cow disease, Foot and mouth disease, Hog cholera, and Poultry Influenza virus. the consumers ara also wanting to have highly safe food such as organic animal products because of concerning about residual of antibiotics in animal products. However, disease control and impairment of productivity are the major problem in organic animal production. On these points of view, the present study was undertaken to investigate the effects of 1% or 2% of dietary probiotics fortified with various minerals on improvement of egg production and egg quality in old lay6r feeding low quality feed mainly composed of food waste, sesame meal, and rice bran. After 4 weeks of experimental feeding, the diameter of spreading of egg white was clearly decreased from 11.2cm of control eggs to 10.5m and 10.1m in 1% and 2% treatment group eggs, respectively. The color of egg yolk was 9.3 in control eggs but remarkably increased in treatment groups showing 10.1~10.2. Egg production was 75.8% in control layers but significantly increased to 79.8% of 1% treatment group and 82.9% of 2% treatment group layers. Egg weights (C : 66.3g, 1% : 73.2g, and 2% : 76.7g) and egg shell thickness (C : 0.33mm, 1% : 0.35mm and 2% : 0.36mm) were also increased by the addition of 1% or 2% of probiotics when compared to those of control group eggs. All together, it has been suggested that dietary addition of probiotics fortified with various minerals can improve the egg quality and egg production in layer's productivities by the recycling of organic waste resources such as food waste and agricultural by-products.

• Journal of Preventive Medicine and Public Health
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• 제53권3호
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• pp.189-197
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• 2020

Objectives: Our aim was to answer the following questions: (1) Can mental health variance be partitioned to individual and higher levels (e.g., neighborhood and district); (2) How much (as a percentage) do individual-level determinants explain the variability of mental health at the individual-level; and (3) How much do determinants at the neighborhood- or district-level explain the variability of mental health at the neighborhood- or district-level? Methods: We used raw data from the second round of the Urban Health Equity Assessment and Response Tool in Tehran (in 2012-2013, n=34 700 samples nested in 368 neighborhoods nested in 22 districts) and the results of the official report of Tehran's Center of Studies and Planning (in 2012-2013, n=22 districts). Multilevel linear regression models were used to answer the study questions. Results: Approximately 40% of Tehran residents provided responses suggestive of having mental health disorders (30-52%). According to estimates of residual variance, 7% of mental health variance was determined to be at the neighborhood-level and 93% at the individual-level. Approximately 21% of mental health variance at the individual-level and 49% of the remaining mental health variance at the neighborhood-level were determined by determinants at the individual-level and neighborhood-level, respectively. Conclusions: If we want to make the most effective decisions about the determinants of mental health, in addition to considering the therapeutic perspective, we should have a systemic or contextual view of the determinants of mental health.

• 한국IT서비스학회지
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• 제8권3호
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• pp.171-184
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• 2009

Since the development of the Distributed Hash Tables (DHTs), the distributed lookup services are one of the hot topics in the networking area. The main reason of this popularity is the simplicity of the lookup structure. However, the simple key based search mechanism makes the so called "keyword" based search difficult if not impossible. Thus, the applicability of the DHTs is limited to certain areas. In this paper. we find that DHTs can be used as the ubiquitous sensor network (USN) metadata lookup service across a large number of sensor networks. The popularity of the Ubiquitous Sensor Network has motivated the development of the USN middleware services for the sensor networks. One of the key functionalities of the USN middleware service is the lookup of the USN metadata, by which users get various information about the sensor network such as the type of the sensor networks and/or nodes, the residual of the batteries, the type of the sensor nodes. Traditional distributed hash table based lookup systems are good for one sensor network. However, as the number of sensor network increases, the need to integrate the lookup services of many autonomous sensor networks so that they can provide the users an integrated view of the entire sensor network. In this paper, we provide a hybrid lookup model, in which the autonomous lookup services are combined together and provide seamless services across the boundary of a single lookup services. We show that the hybrid model can provide far better lookup performance than a single lookup system.

• 국제초고층학회논문집
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• 제8권3호
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• pp.177-183
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• 2019

This paper describes the structural design of a 212 m tall building currently under construction in the Tokiwabashi District Redevelopment Project facing Tokyo Station. In this project there was a requirement to rationally solve many issues arising from the conditions of the redevelopment project. In particular, the following two points were considered to be important from the point of view of structural design. 1) To provide an overhang frame with the perimeter columns on the lower stories inclined, in order to enable a typical floor area that greatly exceeded the limitations of the underground structure shape. 2) To provide high grade seismic performance for the office buildings to be constructed on prime city center land. LSCVCS (Lower Stories Concentrated Vibration Control System) was proposed as the method of rationally designing the overhang frame, which is an extremely disadvantageous element in the structural scheme of the tall building with a large slenderness ratio. LSCVCS is a system to provide effective damping by arranging vibration control devices in a concentrated manner in a lower story with large story height, that produces large deformation in an earthquake. Also, the vibration control devices arranged in the lower story are limited to viscous devices, to take into consideration the residual deformation of the overhang frame after an earthquake. The results of investigations into the specific effects of the system for the seismic design are reported, including Performance-based seismic design.