• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2004년도 학술대회지
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• pp.261-268
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• 2004

For cam and roller-follower contacting surfaces, the effect of tangential loading on the subsurface stress field at an elaso-hydrodynamic lubrication condition has been studied numerically. As tangential load increases, the subsurface stress field extended more widely to the direction of the tangential load. The positions of the maximum shear stress and the maximum effective stress are getting closer to the surface with the increasing tangential load. The tangential load at the elasto-hydrodynamic lubrication condition is of little consequence to the subsurface stress field.

• Wind and Structures
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• 제30권3호
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• pp.245-260
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• 2020

Wind load and responses are the major factors which govern the design norms of tall buildings. Corner modification is one of the most commonly used minor shape modification measure which significantly reduces the wind load and responses. This study presents a comparison of wind load and pressure distribution on different corner modified (chamfered and rounded) Y plan shaped buildings. The numerical study is done by ANSYS CFX. Two turbulence models, k-epsilon and Shear Stress Transport (SST), are used in the simulation of the building and the data are compared with the previous experimental results in a similar flow condition. The variation of the flow patterns, distribution of pressure over the surfaces, force and moment coefficients are evaluated and the results are represented graphically to understand the extent of nonconformities due to corner modifications. Rounded corner shape is proving out to be more efficient in comparing to chamfered corner for wind load reduction. The maximum reduction in the maximum force and moment coefficient is about 21.1% and 19.2% for 50% rounded corner cut.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1992년도 봄 학술발표회 논문집
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• pp.105-110
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• 1992

This study deals with the effect of a series of moving trucks on the Dynamic Load Factor (DLF). The DLF is calculated by investigating the load effect of moving trucks. Therefore, analytical models for frocks, bridge, and road profiles were developed and dynamic structural analysis computer program were developed. Then the DLFs are calculated as a ratio of maximum dynamic load effect and maximum static load effect. Trucks used in this study are 5 axle semi tractor-trailer with the weight of 36 and 54 ton. Simply supported prestressed concrete box girder bridges with 20 and 40m span length are selected. From the results of the DLF for various headway distances, they show a very scattered and relatively high values of the DLF in case of a 20m span length bridge. For a 40m span length bridge, the results show less scattered and small increase of the DLF compared to a 20m span length bridge.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.204-205
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• 2014

Among common test methods of assessing structure safety for existing lightweight walls, the criteria of the quality assessment of the horizontal static load resistance has been considered ambiguous. In the current study, therefore, an experiment was conducted to figure out the standardized assessment criteria of the lightweight wall's horizontal static load resistance. Based on the findings of the experiment with gypsum board and ALC block walls, an acceptable amount of each standard and the variables of the stud wall arising from the appropriate load (1000N) on the wall in a daily life were accounted for, arbitrarily setting the maximum deformation amount below 15mm.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 봄 학술발표회 논문집
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• pp.597-604
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• 2002

The piled raft foundation Is an innovative design concept to reduce both the maximum settlement and differential settlements caused by concentrated building loads and load eccentricities, and also to reduce the bending moments of the raft. The main concern given in the design of piled raft foundations is proper judgments both of relative proportions of loads carried by the raft and piles, and of the effect of the pile support on the maximum and differential settlements In the present study, the piled raft foundation used in the foundation system of Richensia Building at Youido, Seoul is introduced and is carried out analyzing the results of field tests such as plate load tests, large plate load test, pile load test, and piled raft load test.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.835-837
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• 1996

In this paper, a method for the daily maximum load forecasting which uses a chaotic time series in power system and artificial neural network(Back-propagation) is proposed. We find the characteristics of chaos in power load curve and then determine a optimal embedding dimension and delay time. For the load forecast of one day ahead daily maximum power, we use the time series load data obtained in previous year. By using of embedding dimension and delay time, we construct a strange attractor in pseudo phase plane and the artificial neural network model trained with the attractor mentioned above. The one day ahead forecast errors are about 1.4% for absolute percentage average error.

• Computational Structural Engineering : An International Journal
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• 제1권1호
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• pp.11-20
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• 2001

The paper describes the conceptual design, structural modelling and wind load analysis of tall buildings. The lateral stiffness of the building can be obtained economically through the interaction of core walls with peripheral frame tube and/or bundle of frame tubes and integrated design of the basement. The main structural components should be properly distributed such that the building will deflect mainly in the direction of the applied force without inducing significant response in other directions and twist. The cost effectiveness can be further enhanced through close consultation between architects and engineers at an early stage of conceptual design. Simplified structural modelling of the building and its response in three principal directions due to wind load are included. Effects of the two main structural components on the performances of a 70-story reinforced concrete building in terms of peak drift and maximum acceleration under wind load are discussed.

• 한국정보과학회논문지:정보통신
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• 제33권5호
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• pp.395-406
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• 2006

Ad hoc 네트워크에서 노드의 한정된 배터리 잔량 에너지는 전체 네트워크의 수명에 큰 영향을 끼친다. 따라서 이러한 에너지 한계를 극복하기 위해 다양한 power-aware 라우팅 프로토콜들이 네트워크 계층에서 제안되어 왔으며, 이들 power-aware 라우팅 프로토콜들은 기본적으로 노드의 배터리 잔량에너지와 전송 전력량을 경로 탐색 과정에서 반영한다. 본 논문에서 제안하는 power-aware 라우팅 프로토콜 TDPR(Traffic load & lifetime Deviation based Power-aware Routing protocol)은 노드의 배터리 잔량 에너지와 전송 전력량뿐만 아니라 각 노드의 트래픽 부하와 노드 간 예상 수명 편차를 경로 탐색 과정에 반영하여 전체 네트워크의 수명을 연장시키고 노드들 간 에너지 소모가 균등하게 이루어질 수 있도록 한다. ns-2[14] 시뮬레이터를 이용한 TDPR과 기존 라우팅 프로토콜들 간의 비교 실험은 전체 네트워크의 부하 균등, 노드들의 에너지 소모량, 그리고 개설 경로의 안정성 측면에서 TDPR의 개선된 성능을 확인한다. 실험 결과, 네트워크 탈퇴한 노드의 개수 비교에서는 TDPR이 AODV(4)보다 최대 72%, PSR[9]보다 최대 58% 적게 나타났다. 평균 잔량 에너지의 비교에서는 TDPR이 AODV보다 최대 29%, PSR보다 최대 15% 적은 양의 에너지를 소모하는 것을 확인하였으며, 에러 메시지의 발송 횟수 비교에서는 TDPR이 AODV보다 최대 41%, PSR보다는 최대 38% 적은 수의 에러 메시지를 발송하는 것을 확인할 수 있었다.

• 한국지반공학회지:지반
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• 제12권6호
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• pp.79-86
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• 1996

본 연구에서는 일반 토사층에 선단지지된 현장타설말뚝의 재하시험결과로부터 얻은 하중-침하 량곡선을 쌍곡선으로 회귀분석하고 여기에 곡률방정식을 이용하여 최대곡률을 나타내는 하중을 항복하중으로 규정하는 판정법을 개발하였다. 그러나 하중과 침하량의 단위 또는 축척에 따라 최대곡률점의 위치가 변하고 따라서 항복하중도 다르게 판별된다(원상연, 1995). 따라서 하중과 침하량을 정규화(normalization)하고 정규화된 침하량(x축)과 하중축(y축)의 축척이 1:1이 되도록 함으로써 하중과 침하량의 단위와 축척에 상관없이 유일한 최대곡률점을 찾을 수 있었다. 본 논문에서 기존의 판정 법들을 이용하여 각각의 항복하중을 구하고 이들의 평균값을 기준으로 하여 정규화 과정을 검토하였다. 이 판정법을 현장타설말뚝에 대한 연직재하시험결과에 적용하여 연직항복하중을 판정하고, 이 결과를 기존의 판정 법들에 의한 항복하중과의 비교를 실시하였다.

• 한국물환경학회지
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• 제30권3호
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• pp.351-360
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• 2014

The allocation of margin of safety (MOS) at a uniform rate to all areas of the unit watershed makes it very difficult to keep the load allotment stable in the area for lack of reduction measures like forest land. This study developed an equation to calculate margin of safety differentially according to the regional characteristics. The equation was formulated on the basis of the regional characteristic factors such as a load contribution factor for land use type and a site conversion factor for the unit watershed. The load contribution factor represents a contribution of loads from a particular land use. The site conversion factor was derived from the site conversion ratio of a unit watershed. Margin of safety for the non-point pollution load in the land use sector decreased by 20~25% in three river basins. The margin of safety in the unit watersheds with low site occupation ratios decreased in high rate, while in the unit watersheds with large urban area decreased in low rate. With the application of the differential margin of safety considering regional characteristics, not only the reduction of pollution loads can become lighter but also it can be easier to develop plans for Total Maximum Daily Loads (TMDLs) even where the reduction measures are not available.