• 한국지역지리학회지
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• 제9권4호
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• pp.437-460
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• 2003

통일신라시대의 서원경성의 위치는 청주읍성 지역이 되고 있다. 청주의 매장 문화재인 남석교는 신라 진흥왕 19년 무인년(588년)에 수선했다는 기록으로 보아 남석교의 원조는 그 이전으로 소급될 수 있고 그 후에 수차에 걸쳐 개축되었다는 사실도 알 수 있다. 조선시대 청주읍성의 남북 주축도로는 남문을 통과하고 있고 남문 밖의 시장의 발달로 인하여 남문 밖의 무심천에 위치한 남석교의 역할은 지대할 수밖에 없다. 남석교에서 유래된 대교천의 명칭은 조선 철종 12년(1861년)까지는 대교천으로 불렸고 고종 8년(1871년)에는 무성천으로도 불렸으며 광무 2년(1902년) 이후에는 무심천으로 부르게 되었다고 짐작된다. 청주는 풍수지리와 무심천의 지명유래 등으로 부정적인 이미지를 지니기도 하였지만 점차 긍정적인 이미지로 변화되고 있다. "남석교 사적비"는 1907년까지는 존재하였지만 "표석"과 더불어 유실되었고 "남석교"는 $1931{\sim}1932$년 간의 석교동 제방공사 때문에 매몰되었으며 이러한 문화재들은 가치가 매우 크므로 복원되어야 할 것이다.

• 복합신소재구조학회 논문집
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• 제6권2호
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• pp.77-84
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• 2015

The purpose of this study was the analytical safety evaluation on the super-structure of precast modular bridge using standardized modular members and robotic construction during the transportation routing and lifting conditions. In order to evaluate the safety performance of the bridge system, 3-D full scale Finite Element (FE) of 40 m standardized modular block was developed in ABAQUS, followed by the analytical study to classify the structural system according to steel girder structures: 1) modular bridge block lifting method including the steel girder system; 2) modular bridge block lifting method without the steel girder system. The results from the analytical study revealed that the maximum stress of each modular member was within the maximum allowable stresses during lifting condition. However, the stress concentration at the connected area was more critical in comparison to the behavior of 40 m combined modular blocks during lifting time

• 디자인학연구
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• 제18권3호
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• pp.161-170
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• 2005

본 연구는 군산시의 은파유원지내에 설치되는 교량에 관한 기본계획 및 실시설계에 관한 연구이다. 본 교량은 기존에 설치되었던 차량위주의 교량이 아닌 보행자를 위한 보행자 전용교량으로 주변경관과의 조화 및 통과자의 커뮤니케이션 행태와 지역의 역사문화를 고려하여 접근되었다. 이것은 기존의 교량들이 기능적인 요소에 중점을 두어 계획되었던 것과는 다르게 진행하는 통과자의 관점과 지역문화진흥 관점에서 계획되었으므로 공간내에서 인간과 커뮤니케이션 행위와 지역과의 상호작용을 이해하는 사례가 될 것이다. 본 연구의 노선계획 및 교량의 형식과 규모, 주탑의 형식 그리고 그 안에 설치되는 다양한 공간들의 구성방법 및 부대시설들을 통해 경관과 인간행태를 이해할 수 있을 것이며, 대상 지역문화의 활성화를 모색하고 교량설계에 있어 새로운 접근방법을 시도했다는데 본 연구의 의의가 있다 하겠다.

• Wind and Structures
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• 제32권4호
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• pp.293-308
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• 2021

For the past three decades a significant amount of research has been conducted on bridge flutter. Wind tunnel tests for a 2000 m class twin-box suspension bridge have revealed that a twin-box deck carrying 4 m tall 50% open area ratio wind screens at the deck edges achieved higher critical wind speeds for onset of flutter than a similar deck without wind screens. A result at odds with the well-known behavior for the mono-box deck. The wind tunnel tests also revealed that the critical flutter wind speed increased if the bridge deck assumed a nose-up twist relative to horizontal when exposed to high wind speeds - a phenomenon termed the "nose-up" effect. Static wind tunnel tests of this twin-box cross section revealed a positive moment coefficient at 0° angle of attack as well as a positive moment slope, ensuring that the elastically supported deck would always meet the mean wind flow at ever increasing mean angles of attack for increasing wind speeds. The aerodynamic action of the wind screens on the twin-box bridge girder is believed to create the observed nose-up aerodynamic moment at 0° angle of attack. The present paper reviews the findings of the wind tunnel tests with a view to gain physical insight into the "nose-up" effect and to establish a theoretical model based on numerical simulations allowing flutter predictions for the twin-box bridge girder.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.372-372
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• 2012

We have studied a fabrication of Poly (3,4-ethylenedioxythiophene) (PEDOT) wire arrays and structures with various feature sizes from hundreds micrometers to tens nanometers. PEDOT is well-known as a conducting material, can be grown by a vapor pressure polymerization (VPP) method. The VPP technique is a bottom-up processing method that utilizes the organic arrangement of macromolecules to easily produce ordered aggregates. Also, liquid-bridge-mediated nanotransfer molding (LB-nTM), which was reported as a new direct patterning method recently, is based on the direct transfer of various materials from a mould to a substrate through a liquid bridge between them. The PEDOT nanowires grown by VPP method and transferred on a substrate to use LB-nTM method have been investigated by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Selected Area Electron Diffraction (SAED), X-Ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), and electrical properties.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2005년도 춘계 학술발표회 논문집
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• pp.422-429
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• 2005

It is limited to decrease height or section even by system conversion to indeterminate structure - continuous beam - in existing PSC girder bridges. In this study, the movement of connection is analyzed through actual field test, by increasing stiffness of negative moment area in continuous PSC bridge and developing continuous PSC bridge with embedded steel plate, that can overcome the demerit of existing connection. As a result, it is confirmed that the body unification of the connection is being realized and maintained. Moreover, the height of a span is suggested in continuous PSC girder bridge with embedded steel plate by computational analysis

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.511-516
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• 2007

Rubber wheeled AGT(Automated Guide-way Transit) system is a prominence transportation system for urban area, because of its low construction cost and management, low noise and vibration and fine exterior view. AGT system uses concrete tracks. Concrete can be easily damaged by the impact, change of temperature and external loads. The fault of concrete track is harmful not only to riding quality but also to bridge. Therefore, in this study, the effects of railway prominence to the bridge are surveyed by experimental method. The experiment was executed for PSC bridge at AGT test line in Kyungsan. And the test results for 5mm, 10mm prominence and without prominence are compared and investigated, according to the vehicle speed.

• 전자공학회논문지T
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• 제35T권3호
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• pp.96-102
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• 1998

본 논문에서는 스위칭시 ZVS 기능을 갖는 풀 브리지 위상전이 컨버터의 디지털 컨트롤러의 설계에 대해 연구하였다. 디지털 컨트롤러는 인버터나 전동기 구동 시스템에서 넓게 사용되었다. 그러나 디지털 컨트롤러는 고주파 스위칭 파워 서플라이 (특히 풀브리지 DC/DC 컨버터)에는 적용되지 못했었다. 따라서 본 논문에서는 ZVS 기능을 가진 풀 브리지 위상전이 컨버터의 디지털 컨트롤을 위한 방법을 제안하고, 기존의 아날로그 컨트롤러와 비교하였다. 수치 연산 패키지인 MATLAB을 이용한 컴퓨터 시뮬레이션을 통해 제어기 설계를 최적화하였다.

• International Journal of Railway
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• 제2권4호
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• pp.180-186
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• 2009

High speed railway challenge the design, construction and maintaining of traditional railway, many traditional design concepts have been changed. Transition of railway and bridge has two main problems. one is that different lines have different ability of resisting distortion in area of trial load, which was known that problem of smooth transition of stiffness, the other is that differential settlement between artificial structure and earth structure cause bending of railway. The two problems have effect on train moving. The principle of processing transition of railway and bridge is same in world, but it is difficult to find relationship between design standard of transition, vehicle performance, line standard, design speed and so on form documentation and data reports. Based on mechanics, the paper analyzed dynamic performance of transition of high speed railway, studied various rough elements which is effective to train moving, built mathematical model of interaction of train and transition of high speed railway and developed numerical simulation software. In various different work conditions, we did great quantity of numerical simulation, comprehensive analysis and performance analysis.

• KIEAE Journal
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• 제17권3호
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• pp.15-21
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• 2017

Purpose: "Building energy design standard" is used to limit the thermal transmittance of building in Korea. However, it only covers the insulation standard for each appropriate elements of a building, not the thermal performance of Junction thermal bridge of windows and doors installed in wall. Therefore in this study, we have evaluated the thermal performance of Junction thermal bridge depending on installation method and position of windows and provide it as design data. Method: We analyzed heat transfer of 4-Track sliding window and tilt & turn triple glazed window that are placed in the first class category on window energy efficiency rating using Window 7.4 and Therm 7.4. Result : First, linear thermal transmittance of 4-Track sliding window differs by 2.2 times or more depending of installation method and location. It is higher than the linear thermal transmittance, 0.01W/mK, proposed by Passivhaus. Second, linear thermal transmittance of Tilt & turn triple glazed window differs by 7.7 times or more depending of installation method and location. The average linear thermal transmittance was less than 0.01W /mK when windows were installed on the internal wall insulation by the fixed hardware attachment method. Third, the thermal losses of a window caused by a junction thermal bridge are inversely proportional to the window area and converge gradually as the area increased.