• 한국전산구조공학회논문집
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• 제30권6호
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• pp.559-566
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• 2017

본 논문은 시공단계에서 가설지주 설치를 요구하지 않는 역삼각 트러스 거더로 보강된 새로운 합성 데크플레이트 시스템을 제안한다. 제안된 시스템은 기존 시스템 대비 증가된 강성과 강도를 보유할 뿐 아니라 절대 층고 변화를 최소 수준으로 낮출 수 있으며 기존의 H형강 및 U형 합성보와 같은 다양한 형태의 합성보 부재와 함께 사용될 수 있다. 제안된 시스템의 시공단계 하중에 대한 구조적 성능을 평가하기 위해 5.5m의 스팬을 갖는 5개의 시험체를 제작하여 현장 조건과 유사한 재하하중을 단계적으로 적용시켜 실험을 수행하였다. 실험결과로부터 각 시험체 별 하중-변위 그래프를 구해 비선형 3차원 유한요소해석결과와 비교하였다. 비교 결과 보강 트러스 거더와 데크플레이트 사이에 효율적인 하중 분배가 이루어져 두 구조요소가 잘 일체화되었을 뿐 아니라 시공단계 하중에서의 최대 처짐이 건축구조기준의 제한치를 하회하여 사용성 조건을 잘 만족시킴을 알 수 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 C
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• pp.1745-1747
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• 2004

In order to anticipate gradual increase of fault current in electric power systems, current limiting technology and current limiting device has been investigated for a long time. But the commercial use of current limiting device was delayed due to the lack of effective method to insert impedance to the elective power systems without loss and surplus defects. However, novel current limiting device, which use superconducting materials, was considered as a dream technology to be applied in a distribution and transmission lines. LG Industrial systems and KERPI started to investigate resistive type superconducting fault current limiters in order to develop 154kV fault current limiters and this year, we succeed to test 3 phase 6.6kV/200A fault current limiters. Based on these achievements, 24kV superconducting fault current limiters will be realized withing 3 years which could be tested in a real fields. In this paper, the developments of fault current limiting module which use YBCO thin films, cryogenic systems, the structure and construction of 3 phase fault current limiters and finally the test results of 6.6kV superconducting fault current limiters will be introduced.

• 한국수소및신에너지학회논문집
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• 제25권2호
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• pp.173-182
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• 2014

Dimethyl ether (DME) is a new clean fuel as an environmentally-being energy resources. DME has similar characteristics to those of LPG and can be substituted Diesel fuel. KOGAS has investigated and developed new innovative DME synthesis process from synthesis gas with KOGAS's own technologies. KOGAS had finished the construction of 10ton/day DME demonstration plant in 2008, we have established the basic design of commercial plant which can produce 3,000ton/day DME. Specifically, an economic model for a commercial DME project will be presented. It accounts for all the major cost factors that are considered in a commercial scale project as the model input for performing cash flow analysis, after which key economic indicators are produced including the internal rate of return (IRR), net present value (NPV). Sensitivity analysis is performed to identify dominant cost factors to the project economics and quantify their impact. The inputs to the economic analysis will be based on representative cost factors from the commercial-scale design of KOGAS' direct DME process supplemented by literature data. Case study results will be presented based on recent commercialization projects.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.322-330
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• 2009

Traffic congestions in local cities have been getting worse since 1990s, so many local governments have considered the introduction of an LRT system. So far, there is no city operating the LRT due to social environments, financial reasons, feasibility and so on. But still many cities have examined LRT or started the construction. Until now, more than 30 cities are constructing LRT or planning the introduction of LRT and it becomes 96 routes, approximately 700km. With the support of MLTM, KRRI has developed automatic LRT system with rubber-wheels, K-AGT as a result of "LRT system technology development project" from 1999 to 2005 by investing 50.32 billion wons(the public 37, the private 13.32) and finished running durability test of 100,000km at Kyeong-san test line. Currently, two trains, coupled two cars respectively have running and signaling tested. K-AGT was appointed to supply for an extension line at Busan Subway Line 3(Minam-Anpyeong section) with 17 trains(six-unit car) 102 cars. However, except for Minam-Anpyeong section, other cities such as Uijeongbu, Yongin, Daegu(Line 3) and Kwangmyeong decided to use the foreign systems, not to use the product, a result of national R&D project. This results in a huge waste of foreign currency and it is expected to require much additional cost for maintenance. If local governments use the products of national R&D projects, many national benefits such as reducing imports and protecting home industries could be expected, therefore in this paper, some plans to encourage to use products of national R&D projects were dealt with.

• 드라이브 ㆍ 컨트롤
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• 제19권4호
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• pp.46-53
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• 2022

RIn this study, a test tractor that could measure various types of agricultural operational loads was developed, and its performance was verified. This tractor could be used to measure the load generated during agricultural work and convert the related data into a database. A test tractor was developed using an 80-kW-rated load tractor, and it could measure various types of field test data, such as engine torque and rpm, wheel torque, PTO(power take-off) torque, hexometer, IMU/INS sensor, steering angle sensor, hydraulic pressure, and flow sensor data. To verify the developed test tractor, a verification test using an agriculture rotavator was performed. The test conditions were L1, L2, and L3 based on the tractor's main and sub-transmission stages, and stages 1 and 2 were selected as the PTO. In a comparison of the analyzed test data, similar tendencies in the test results of this research and other research (Kim's research) were seen. Through this, the developed test tractor was verified. In the future, we plan to conduct research on the tractor developed in this study using various attached working machines.

• 대한토목학회논문집
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• 제35권6호
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• pp.1395-1404
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• 2015

본 연구는 도로교통분야 기술수준의 정량적인 평가와 기술개발, 국토교통 R&D의 전략적 방향 모색 및 기술정책 수립 등 수요에 대응할 수 있는 기초자료 제공을 목적으로 수행하였다. 이를 위해 도로교통분야의 기술 분류체계를 구축하고 기술별 핵심 키워드를 도출하여 한국, 미국, 일본, 독일, 프랑스, 영국의 기술수준 조사를 실시하였다. 기술수준 평가결과 미국이 모든 기술분야에서 최상의 특허 및 논문기술경쟁력을 보유한 것으로 나타났다. 한국의 경우 전반적으로 중상위권의 기술경쟁력을 보유한 것으로 나타났으나, 기술별 편차가 있는 것으로 나타났다. 본 연구결과는 향후 도로교통분야 기술개발 및 계획수립 시 기초자료로 활용될 수 있다.

• 한국지진공학회논문집
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• 제17권2호
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• pp.79-88
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• 2013

Steel plate concrete (SC) composite structure is now being recognized as a promising technology applicable to nuclear power plants as it is faster and suitable for modular construction. It is required to identify its dynamic characteristics prior to perform the seismic design of the SC structure. Particularly, the damping ratio of the structure is one of the critical design factors to control the dynamic response of structure. This paper compares the criteria for the damping ratios of each type of structures which are prescribed in the regulatory guide for the nuclear power plant. In order to identify the damping ratio of SC shear wall, this study made SC wall specimens and conducted experiments by cyclic lateral load tests and vibration tests with impact hammer. During the lateral loading test, SC wall specimens exhibited large ductile capacities with increasing amplitude of loading due to the confinement effects by the steel plate and the damping ratios increased until failure. The experimental results show that the damping ratios increased from about 6% to about 20% by increasing the load from the safe shutdown earthquake level to the ultimate strength level.

• 대한토목학회논문집
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• 제36권2호
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• pp.317-324
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• 2016

본 연구는 현수교 분야 기술수준의 정량적인 평가와 기술개발, 국토교통 R&D의 전략적 방향 모색 및 기술정책 수립 등 수요에 대응할 수 있는 기초자료 제공을 목적으로 수행하였다. 이를 위해 현수교 분야의 기술 분류체계를 구축하고 기술별 핵심 키워드를 도출하여 한국, 미국, 일본, 독일, 영국의 기술수준 조사를 실시하였다. 기술수준 평가결과 미국과 일본이 모든 기술분야에서 상위의 특허 및 논문기술경쟁력을 보유한 것으로 나타났다. 한국의 경우 전반적으로 중위권의 기술경쟁력을 보유한 것으로 나타났으나, 기술별 편차가 있는 것으로 나타났다. 본 연구결과는 향후 현수교 분야 기술개발 및 계획수립 시 기초자료로 활용될 수 있다. 그리고 기술 경쟁국간의 기술 수준 비교 방법론의 표준화를 위한 연구에 활용 될 수 있다.

• 한국건축시공학회지
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• 제23권1호
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• pp.45-56
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• 2023

본 연구는 PC공법에 적용되는 실링재를 대상으로 수밀성 측면의 내구성 평가방안 마련의 타당성을 검토하기 위하여 진행하였다. 이를 위해 관련 KS표준의 품질기준에 동일하게 만족하는 실링재 5종을 선정하여 시험을 진행하였으며, 시험결과 5종의 실링재 중 3개 실링재가 바탕면과의 탈락 및 균열 등 수밀성 저하를 나타냈으며, 2종의 경우 육안관찰 상 큰 변화는 없었으나, 추가분석을 통해 소재의 응력 저하율의 차이가 크게 발생하는 것을 확인할 수 있었다. 이에 상기 결과를 근거로 향후 실링재 간 수밀성 측면의 성능검토 필요성을 확인하였으며, 이를 기반하여 제품 선정 시 활용 가능한 수밀성 평가방안의 타당성을 정량적으로 확인하였다.

• Industrial Engineering and Management Systems
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• 제11권2호
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• pp.202-214
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• 2012

This paper discusses the problem of determining locations for public health-care facilities and allocating patients to the public facilities with the objective of minimizing the total construction cost. The public health-care facilities have two types of facilities: public hospitals and health centers. The public hospital provides both hospital services and homecare services, while the health center provides only homecare service. We present an integer programming formulation for the problem, and develop two types of heuristics, based on priority rules and approximate mathematical formulation. Results of a series of computational experiments on a number of problem instances show that the algorithms give good solutions in a reasonable computation time.