• 지구물리
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• 제9권4호
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• pp.321-331
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• 2006

최근 급격한 인구증가와 산업화, 도시화로 포장지역의 증가에 따른 불투수지역의 증가로 유역의 유출 특성의 변화를 유발시키고 있다. 도시화 유역의 효율적인 관리를 위해서는 유역에 대한 정확한 지형인자 및 수문관련 인자들이 추출되어야 함에 따라 본 연구에서는 지리정보체계와 유전자알고리즘의 결합을 통하여 입력정보의 정확성을 향상시키고, 매개변수를 추정하였다. 이러한 목적에 따라 본 연구에서는 전형적인 한국의 도시화하천으로서 본류와 상류로부터 오전천, 당정천 등의 지류를 지니고 있는 안양천을 연구대상으로 선정하여 유출량 해석에 XP-SWMM을 적용하였고, 이의 적용과정을 개선하기 위하여 지리정보체계와 유전자 알고리즘을 적용하였다. XP-SWMM 매개변수들의 민감도 분석을 통하여 도시 유출의 거동특성을 조사하였으며, 이를 바탕으로 매개변수들의 개선규칙을 설정하였고 이러한 규칙 및 사실등을 통하여 유전자 알고리즘을 구성하였다. GIS를 이용하여 지형도로부터 각각의 소유역에 대하여 면적, 경사도, 유역폭 등 수문정보를 얻었고, 토지이용도와 토양도로부터 불투수비, 토지이용상태, 침투능에 대한 정보를 얻었다. 도시유출 모형인 XP-SWMM을 선택하여 모의 후 민감도 분석을 통해 선정된 매개변수에 대하여 보정은 자동보정으로 무작위 탐색법의 일종인 유전자알고리즘(Genetic Algorithm, GA)을 사용하여 매개변수들을 추정하였고, 이의 적용성을 확인하였다.

• 한국철도학회논문집
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• 제19권4호
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• pp.515-525
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• 2016

도시형 자기부상열차 프리텐션 거더교의 최적설계를 위해서 설계변수 분석을 수행하였다. 자기부상철도용 거더 설계 시에는 중앙부 처짐을 고려해야 하므로 이와 연관있는 콘크리트 압축강도, 거더 형고, 거더 연장및 강연선비부착 길이를 설계변수로 선정하였다. 또한, 프리텐션 거더에서 지점부의 상연응력을 제어하기 위해서 강연선 개소수 및 배치방식을 설계변수로 선정하고, 강연선비부착률을 검토하였다. 설계변수 해석결과로부터 거더 처짐량에는 거더 형고와 거더 연장이 콘크리트 압축강도와 강연선 비부착 길이보다 더 큰 영향을 미치는 것을 확인하였고, 민감도 분석을 통해 설계 가중값을 제시하였다. 지점부 상연응력 제어를 위해서 비부착 강연선배치기준을 만족하는 경우에는 상연 긴장선 또는 철근배근이 필요한 것으로 확인되었다. 따라서 향후 경제성 및 시공성 향상을 위해 자기부상철도 가이드웨이의 하중특성을 고려한 비부착강연선 기준 향상에 대한 검토가 필요하다.

• 한국도시철도학회논문집
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• 제6권4호
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• pp.339-350
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• 2018

도시철도에서 지하 터널의 미세먼지는 여러 가지 요인에 의하여 발생하고 있다. 도시철도 미세먼지 발생량을 예측하기 위하여 여러 가지 발생요인 중 레일 마모량 분석에 관한 연구를 수행하였다. S호선 구간(약 45km)에서 1년 6개월 간 레일마모측정장치에서 측정된 레일 마모 데이터를 곡선반경(R)의 변화에 따라 약 170개 구간으로 구분하였으며, 레일 마모 측정값 중에서 직마모량(C0)와 편마모(V0)량을 이용하여 곡선반경에 따른 레일 마모량 관계를 분석하고, 직선구간과 곡선구간에서 각각 구간평균 편 직마모량과 노선평균 편 직마모량을 산출하였다. 레일 마모량과 레일 단면적의 상관관계를 분석하여 단면적에 대한 근사식을 구하고, 레일 C0와 V0의 변화량을 이용하여 레일 마모에 의한 미세먼지 발생량을 산정하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.1244-1247
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• 2002

The blending brake is mixed brake system which is operated by electrical and mechanical brake simultaneously. Most of urban transit system is used with blending brake unit. In order to train is align at the stopping position. The blending brake shall be presicely operated to the train. Many parameters are influence on the train when train is stopped on presicion position by blending brake. It is considered such parameters as decceleration, variable load, jerk, friction cofficient, etc. Therefore, This paper consider the parameter and describes the blending control for standard EMU. The control algorithm of it is proposed and simulation of it carried out by using MATLAB. Also Electronic control unit is manufactured with micro procesor which is configured fot blending control and is verified by performance test.

• 한국안전학회지
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• 제27권2호
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• pp.1-6
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• 2012

Uniaxial and biaxial torsional fatigue tests were conducted on the samples extracted from urban railway wheel steel. Ultimate and yield strengths of the steel were 1027.7 MPa and 626 MPa, respectively. The uniaxial fatigue limit was 422.5 MPa, corresponding 67% of the ultimate tensile strength. The ratio of ${\tau}_e/{\sigma}_e$ was 0.63. Fatigue strength coefficient and exponent were 1319.5 MPa and 0.339, respectively. Maximum principal and equivalent strain were found to be adequate parameter to predict fatigue lifetime of the steel under multiaixal fatigue condition.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.621-629
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• 2011

Uniaxial and biaxial torsional fatigue tests were conducted on the samples extracted from urban railway wheel steel. Ultimate and yield strengths of the steel were 1027.7 MPa and 626 MPa, respectively. The uniaxial fatigue limit was 422.5 MPa, corresponding 67% of the ultimate tensile strength. The ratio of ${\tau}_e/{\sigma}_e$ was 0.63. Fatigue strength coefficient and exponent were 1319.5 MPa and 0.339, respectively. Maximum principal and equivalent strain were found to be adequate parameter to predict fatigue lifetime of the steel under multiaixal fatigue condition.

• International Journal of Internet, Broadcasting and Communication
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• 제9권2호
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• pp.42-47
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• 2017

In these days, the size of urban is growing and the function of city becomes complicated. And also, in city, people lives a lot. The life of urban is getting closer and linked with neighboring people in many parts. Especially, when peoples are exposing during using public transportation, even though does not be known, in they were living. Seoul is the most crowded place in Korea. In Seoul,The village buses have been serviced to the narrow streets. And people who use this bus, wants to seek the comfort of the ride, air quality and noise during in vehicle. In this paper, we determine the degree of annoyance with the noise inside the town bus in dB scale. And, such a situation was confirmed annoyance see their effect. The Interior noise did not see a big difference in the new car and the old car. Annoyance but also according to the skill of the bus driver remains the difference was confirmed.

• Structural Engineering and Mechanics
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• 제21권4호
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• pp.375-392
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• 2005

Cable supported structures offer an elegant and economical solution for bridging over long spans with resultant low material content and ease of construction. In this paper, a model of shallow cable supported footbridge with reverse profiled pre-tensioned cables is treated and its load deformation characteristics under different quasi-static loads are investigated. Effects of important parameters such as cable sag and pre-tension are also studied. Numerical results performed on a 3D model show that structural stiffness of this bridge (model) depends not only on the cable sag and cross sectional areas of the cables, but also on the pre-tension in the reverse profiled cables. The tension in the top supporting cables can be adjusted to a high level by the pre-tension in the reverse profiled bottom cables, with the total horizontal force in the bridge structure remaining reasonably constant. It is also evident that pre-tensioned horizontally profiled cables can greatly increase the lateral horizontal stiffness and suppress the lateral horizontal deflection induced by eccentric vertical loads.

• 국제초고층학회논문집
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• 제4권2호
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• pp.109-116
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• 2015

The concept of vertical living has been hailed as a solution to control fast growth and urbanization of cities worldwide. As super tall residential projects become more common and sustainability considerations become more necessary, their efficiency has been called into question. How do vertical residential developments compare with suburban homes? What are the environmental advantages and disadvantages of vertical communities? Is there a middle ground? We present the results from an AS+GG study that compares the environmental performance of different housing typologies ranging from a 215 supertall building to single family residences, including several scales in between. Our samples comprise 2,000 residential units per type and include the infrastructure needed to support them. We analyzed land use, energy use, and lifecycle carbon emissions for each typology. The results show that different typologies perform better depending on the parameter being assessed. We discuss these findings; assess overall performance, and present conclusions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권11호
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• pp.4483-4501
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• 2020

Recent findings identified the scatter and shape of MFD (macroscopic fundamental diagram) is heavily influenced by the spatial distribution of link density in a road network. This implies that the concept of MFD can be utilized to divide a heterogeneous road network with different degrees of congestion into multiple homogeneous subnetworks. Considering the actual traffic data is usually incomplete and inaccurate while most traffic partition algorithms rely on the completeness of the data, we proposed a three-step partitioned algorithm called Iso-MB (Isoperimetric algorithm - Merging - Boundary adjustment) permitting of incompletely input data in this paper. The proposed algorithm was implemented and verified in a simulated urban transportation network. The existence of well-defined MFD in each subnetwork was revealed and discussed and the selection of stop parameter in the isoperimetric algorithm was explained and dissected. The effectiveness of the approach to the missing input data was also demonstrated and elaborated.