• 한국공간구조학회논문집
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• 제13권4호
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• pp.75-81
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• 2013

The circular hollow section is usually used for member of main frame to carry the external load in single layer lattice dome. But, the H-shaped section may be used for member of main frame since it is convenient for attaching roof panels. Single layer lattice domes have various buckling characteristics, such as the overall buckling, the member buckling, and nodal buckling. The purpose of this study is to compare buckling characteristics of single-layer lattice domes in which the H-shaped steel section as the existing domestically-produced structural steel is used as main frames to those of domes in which a circular hollow section is used as main frames.

• 국제초고층학회논문집
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• 제8권3호
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• pp.201-209
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• 2019

This paper presents a structural design of the "(Tentative Name) Toranomon Hills Residential Tower" which is currently under construction in Tokyo. The building is a reinforced concrete high-rise residential complex building with 54 stories above ground, 4 basement levels, and a building height of about 220 m. It is a requirement to provide the highest grade of residence in Japan, and in terms of the structural design, it is required to provide wide and comfortable spaces with high seismic performance. These requirements are satisfied by providing a total of 774 vibration control walls of two types. Also, to further improve the structural performance, steel fibers at the rate of 1.0vol% are provided in the ultra-high strength concrete used in the column members.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권1호
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• pp.16-22
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• 2003

While passing through the AC/DC section insulators installed at electric railroad catenary, some electric trains undergo mis-operation of main circuit breaker after AC/DC change-over operation. This paper provides insulation resistance measurements of AC/DC section insulators, which confirm the insulation levels of section insulators are below the standard of insulators. The insulation deterioration and pantograph arrangement on the electric train can produce voltage impression on section insulator which induces mis-operation of main circuit breaker To mitigate the insulation deterioration of the section insulator installed at underground railroads, the section insulators have been cleaned periodically, but section insulator structure should be modified to make the section insulator performance perfect. Based on the above analysis, effective modification method of AC/DC section insulator is provided.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.634-643
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• 2011

The neutral section was installed in order to prevent conflict with different phase angle source in electric railway catenary system. The speed of electric train reduced due to coasting operation by notch off when it passed the neutral section. And, the catenary wire was damaged and the accident might be happened because of the arc generation when the electric train passed the neutral section with notch off condition. The inrush current of main transformer installed tiling train is analyzed during the operation of MCB(main circuit break) passing through the neutral section. The instantaneous waveform of load current were analyzed in case of powering and regenerative braking. Inrush current waveform with run of AC railway train showed that inrush current waveform and harmonics, the inrush current generated from main transformer in train has bad effects on power quality problem. In order to reduce these inrush currents, the MCB is connected when the phase angle of voltage is 90 degree. This paper is to measure inrush current and harmonics in main transformer of high speed train in neutral section of electric railway. This measurement report is used to control minimum inrush current in algorithm and power phase angle.

• 한국조경학회지
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• 제28권1호
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• pp.136-146
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• 2000

Although the urban elevated road is welcomed in modern society to deal with urban traffic problems, its negative influence on both the pedestrian environment and urban landscape has been frequently observed. Furthermore, the space under elevated structures has been ignored, being the lost space. Recently, several efforts have been devoted into bringing back the lostspace. However, any specific design guidelines shown in the street design of Japan and Singapore have not been suggested in Korea, yet. This study proposes a case of the Nengdong-Ro street design where the two-story urban elevated road is being constructed and negative effects of the elevated road are largely expected. One of the purposes of Nengdong-Ro street design proposed in this study is to relieve the negative effect os the two-story elevated road, and to provide a better pedestrian environment in Nengdong-Ro. The other purpose is to suggest general guidelines that can be applied to the similar context as Nengdong-Ro. It is considered that the space under the elevated road generally consist of three sections: 1) main section where the elevated road runs parallel with the ground, 2) landing section where elevated road goes down to the ground, and 3) facility section where facilities such as the platform and the ticketing booth are located. The design guidelines are suggested for each section, because each section has a different situation. Plans, section and elevations and the details of the street furniture are also incorporated to support the design guidelines.

• 국제초고층학회논문집
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• 제3권1호
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• pp.35-48
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• 2014

In designing a 300 meter high skyscraper expected to be the tallest building in Japan, an earthquake-ridden country, we launched on the full-scale performance based design to ensure redundancy and establish new specifications using below new techniques. The following new techniques are applied because the existing techniques/materials are not enough to meet the established design criteria for the large-scale, irregularly-shaped building, and earth-conscious material saving and construction streamlining for reconstructing a station building are also required: ${\bullet}$ High strength materials: Concrete filled steel tube ("CFT") columns made of high-strength concrete and steels; ${\bullet}$ New joint system: Combination of outer diaphragm and aluminium spray jointing; ${\bullet}$ Various dampers including corrugated steel-plate walls, rotational friction dampers, oil dampers, and inverted-pendulum adaptive tuned mass damper (ATMD): Installed as appropriate; and ${\bullet}$ Foundation system: Piled raft foundation, soil cement earth-retaining wall construction, and beer bottle shaped high-strength CFT piles.

• 국제초고층학회논문집
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• 제7권3호
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• pp.255-264
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• 2018

This paper introduces three distinctive means for the use of a 189-meter high damped structure ensuring safety against earthquake: 1. Realization of L-shaped elevational structural planning: The bottom and top of the tower have belt trusses and hat trusses respectively to restrain the bending deformation. Furthermore, large-capacity oil dampers (damping force 6,000 kN) are installed in the middle part of the tower to restrain the higher-mode deformation. 2. Realization of L-shaped planar structural planning: We devised a means of matching the centers of gravity and rigidity by adjusting planar rigidity. Moreover, viscous damping devices are located at the edges of the L-shaped plan, where torsional deformation tends to be amplified. We call this the "Damping Tail" system. 3. Composite foundation to equalize deformations under different loading conditions: We studied the vertical and horizontal deformations using sway-rocking and 3D FEM models including the ground, and applied multi-stage diameter-enlarged piles to the tower and a mat foundation to the podium to keep the foundations from torsional deformations and ensure structural safety.

• 항공우주시스템공학회지
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• 제15권1호
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• pp.72-79
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• 2021

본 연구에서는 신개념 항공교통수단으로 활용될 자율비행 개인항공기 개발의 일환으로 자율비행 개인항공기 주익조립체의 등가모델을 생성한 후 고유모드 해석을 통해 생성된 등가모델의 신뢰성을 검증하였다. 주익조립체는 주익, 안쪽파드, 바깥쪽 파드로 구성되어 있다. 먼저, 각 부품의 등가모델을 생성하기 위해서 해당 부품을 몇 개의 구역으로 분할하고, 각 구역의 양 끝단에 등가모델 축상에 놓이는 절점들을 생성하였다. 그리고, 단위하중과 단위모멘트을 부과한 정적해석을 통해 변형량 또는 회전량을 계산하고, 빔 이론식을 적용하여 각 부품들의 등가 축강성, 굽힘강성, 비틀림강성을 계산하였다. 그리고, 각 구역 중앙에 집중질량을 생성하여 질량과 관성모멘트 정보를 입력하고, 빔 요소를 사용하여 등가모델을 생성하였다. 최종적으로 상세모델의 모드해석 결과와의 비교를 통해 생성된 등가모델의 신뢰성을 확인하였다.

• 한국구조물진단유지관리공학회 논문집
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• 제28권4호
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• pp.1-12
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• 2024

본 연구에서는 강사장교의 비선형 거동과 하모니 서치 알고리즘에 기반한 사장교 부재 단면 결정 방법을 제시하였다. 하모니 서치 알고리즘은 초기값 설정, 하모니 메모리 초기화, 새로운 하모니 메모리 구성 및 하모니 메모리 업데이트의 과정을 반복하여 최적값을 탐색함으로써 사장교 부재 단면을 결정한다. 하모니 서치 알고리즘으로 선정된 주요 부재 단면으로 3차원 강사장교의 비선형 초기형상해석을 수행하였으며, 초기장력과 형상을 고려하여 복잡한 거동특성과 각 부재의 비선형성을 반영한 사장교 주요 부재인 주탑, 보강거더, 가로보 및 케이블의 최적 단면을 결정하였다. 사장교 주요 부재의 단면 결정을 위한 목적함수로는 전체 중량을 사용하였으며, 제약조건으로 한계상태설계법을 바탕으로 하중저항능력과 사용성에 대한 제약조건식 및 보강거더와 가로보 단면의 폭과 높이의 비율을 추가적인 제약조건으로 고려하고, 주탑, 보강거더 및 가로보의 기하 및 재료 비선형성과 케이블 부재의 비선형성에 따라 부재 단면을 결정할 수 있도록 하였다. 최적 단면 결정 결과, 제안한 해석 방법은 사장교의 다양한 설치조건에 따라 최적 단면을 결정할 수 있으며, 비선형성을 고려한 사장교 부재 단면제원을 하모니 서치 기법을 통하여 결정할 수 있음을 확인하였다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1998년도 IUMRS-ICEM ABSTRACT BOOK
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• pp.55.1-55
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• 1998