• 한국실내디자인학회:학술대회논문집
• /
• 한국실내디자인학회 2006년도 추계학술발표대회 논문집
• /
• pp.219-222
• /
• 2006

Architecture is builded on the ground and affected environment which include shape of topography and situation. What this study saying is the analysis about the relation between the concept of structural geomorphology and the space modern architecture. As there are many issue about boundary of space and organic architecture, It is important what study about structural geomorphology In paper, we will aware that there are many similarities between architecture and topography. Notion of folded structure in structural geomorphology is connected with continuity or infinity. This is one of many example.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2009년도 제40회 하계학술대회
• /
• pp.1948_1949
• /
• 2009

All the power generating station require dc auxiliary power systems to operate those dc components that must be available if a loss of ac power occur. Some examples of such components are auxiliary motors, circuit breakers, relays and solenoids. The dc source may be one common battery for both power and control or two separate batteries; one for power and another for control. Typically, a dc auxiliary power system is designed as an ungrounded system, instead of grounded system, so that a low-resistance ground fault on one of its two polarities will not affect the operation of the system, thus increasing system reliability and continuity of service. A ground detector should provide a high polarity-to-ground resistance so that a single ground fault occurring on the system will not affect the operation of that system. Sensitive relays have been known to energize momentarily while the cable and capacitive charge to ground shifts[1]. A power station had experienced this kind of incident and performed root cause analysis based on PC based simulation program known as PSpice. This simulation showed adapted relays on the system energize momentarily and design criteria on this relay should be corrected.

• Journal of Advanced Marine Engineering and Technology
• /
• 제33권2호
• /
• pp.355-361
• /
• 2009

Onshore wind farms having several problems, difficult to secure a building site and incur the enmity of the people. Therefore, offshore wind farms are increasingly expected, because there are huge resource and large site in offshore. If huge wind turbines are constructed, the offshore wind power base is concerned about subsidence. In order to confirm the ground stability, estimation of subsidence is necessary. In this paper, the subsidence is predicted by continuity model when the gravity and the mono-pile base are constructed on soft ground. The FLAC 3D, three dimensional FDM program, was adopted to analysis subsidence. Input factors are yielded by geological information at the yeompo quay in ulsan and the results of laboratory experiments. It has been compared that the original ground with improved ground under the gravity base, and constructed mono-pile under the mono-pile base.

• 대한원격탐사학회지
• /
• 제38권1호
• /
• pp.33-43
• /
• 2022

This study presents a method to restore an optical satellite image with distortion and occlusion due to fog, haze, and clouds to one that minimizes degradation factors by referring to the same type of peripheral image. Specifically, the time and cost of re-photographing were reduced by partially occluding a region. To maintain the original image's pixel value as much as possible and to maintain restored and unrestored area continuity, a simulation restoration technique modified with the Cycle Generative Adversarial Network (CycleGAN) method was developed. The accuracy of the simulated image was analyzed by comparing CycleGAN and histogram matching, as well as the pixel value distribution, with the original image. The results show that for Site 1 (out of three sites), the root mean square error and R² of CycleGAN were 169.36 and 0.9917, respectively, showing lower errors than those for histogram matching (170.43 and 0.9896, respectively). Further, comparison of the mean and standard deviation values of images simulated by CycleGAN and histogram matching with the ground truth pixel values confirmed the CycleGAN methodology as being closer to the ground truth value. Even for the histogram distribution of the simulated images, CycleGAN was closer to the ground truth than histogram matching.

• 문화기술의 융합
• /
• 제6권2호
• /
• pp.467-472
• /
• 2020

일반적인 보통 등급의 지반(ground) 상 구조물의 안정성 확보를 위한 설계입력정수(input-parameters) 도출방법들은 보편적으로 잘 알려져 있다. 연구지역과 같은 습곡된(folded) 변성암(metamorphic rocks) 지반은 엽리가(foliation) 촘촘히 발달해 있고, 엽리에 평행한 소규모 단층들(faults)이 분포하고 있어 설계입력정수 도출을 위한 특별한 조사방법 및 시험, 등이 요구된다. 수 mm 간격의 엽리가 발달한 변성암 지반은 엽리면 직접전단강도시험(direct shear test), 엽리의 배향(strike/dip)과 맵핑(mapping), 엽리의 지하 연속성 파악을 위한 시추조사, 변성암반의 암반분류(rock mass rating), 등이 필요하다. 특정 엽리면을 따라 발달한 소규모의 엽리평행단층(foliation-parallel faults)이 다수 발달한 지반은 선구조선 분석, 단층 추적을 위한 지표지질맵핑, 단층면 직접전단강도시험, 등이 필수적이다. 습곡지반은 지질구조구(structural domain) 분석, 불연속면의 평사투영(stereonet)해석, 습곡축을 따른 전기비저항탐사, 등의 추가조사로 설계입력정수 도출이 합리적이다.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 1995년도 추계 학술대회논문집
• /
• pp.55-63
• /
• 1995

The flow field around a high-speed train including cross-wind effects has been simulated. This study solves 3-D unsteady incompressible Navier-Stokes equations in the inertial frame using the iterative time marching scheme. The governing equations are differenced with 1st-order accurate backward difference scheme for the time derivatives, 3th-order accurate QUICK scheme for the convective terms and 2nd-order accurate central difference scheme for the viscous terms. The Marker-and-Cell concept was applied to efficiently solve continuity equation, which is differenced with 2nd-order accurate central difference scheme. The 4th-order artificial damping is added to the continuity equation for numerical stability. A C-H type of elliptic grid system is generated around a high-speed train including ground. The Baldwin-Lomax turbulent model was implemented to simulate the turbulent flows. To validate the present procedure, the flow around a high speed train at constant yaw angle of $45^{\circ}\;and\;90^{\circ}$ has been simulated. The simulation shows 3-D vortex generation in the lee corner. The flow separation is also observed around the rear of the train. It has concluded that the results of present study properly agree with physical flow phenomena.

• 대한원격탐사학회지
• /
• 제28권1호
• /
• pp.69-77
• /
• 2012

표면도달일사량은 전 지구시스템에 대한 기후 연구에 가장 중요한 요소 중 하나다. 기후 연구에서는 동일 지역을 관측하는 두 개 혹은 그 이상의 위성자료로부터 넓은 공간적 범위를 가지는 장기간의 데이터를 사용하는 것이 필요하다. 시간적 연속성을 가지는 서로 다른 위성으로부터 산출 된 표면도달일사량의 연속성과 일관성을 향상시키는 것은 매우 중요하다. 본 연구에서는 물리적 모델을 이용하여 GOES-9과 MTSAT-1R 위성의 중복 관측 기간 동안의 표면도달일사량을 산출하고, 두 위성의 채널자료와 실측치 비교를 통해 위성간의 연속성과 일관성을 향상시키는 방법을 연구하였다. 두 위성의 적외 채널 온도는 매우 잘 일치하는 경향을 보였다 : RMSE=5.595 Kelvin; Bias=2.065 Kelvin. 반면에, 가시채널은 다른 값의 분포를 보였지만 비슷한 경향을 보였다. 그리고 두 위성으로부터 산출 된 표면도달일사량은 실측치와 일치성이 낮았다. 표면도달일사량의 품질 향상을 위해 구름감쇠계수 조정을 통해 표면도달일사량 산출물을 재생산하였다. 그리고 채널 자료의 비교 분석을 통해 GOES-9 위성을 위한 구름감쇠계수를 생산하였다. 그 결과, 구름 효과를 고려한 GOES-9의 표면도달일사량 산출물은 MTSAT-1R과 실측치에 대해 매우 높은 일치성을 보였다 : RMSE=$83.439W\;m^{-2}$; Bias=$27.296W\;m^{-2}$. 구름감쇠계수 조정을 통해 향상 된 정확도는 두 개 이상의 위성으로부터 산출 된 표면도달일사량 산출물의 연속성과 일관성을 향상 시킬 수 있을 것이다.

• 한국지진공학회:학술대회논문집
• /
• 한국지진공학회 2000년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2000
• /
• pp.81-88
• /
• 2000

The elastic wave equation is solved using the finite-difference method in 3D space to simulate the seismic wave propagation. It is based on the velocity-stress formulation of the equation of motion on a staggered grid. The nonreflecting boundary conditions are used to attenuate the wave field close to the numerical boundary. To satisfy the stress-free conditions at the free-surface boundary, a new formulation combining the zero-stress formalism with the vacuum one is applied. The effective media parameters are employed to satisfy the traction continuity condition across the media interface. With use of the moment-tensor components, the wide range of source mechanism parameters can be specified. The numerical experiments are carried out in order to test the applicability and accuracy of this scheme and to understand the fundamental features of the wave propagation under the generalized elastic media structure. Computational results show that the scheme is sufficiently accurate for modeling wave propagation in 3D elastic media and generates all the possible phases appropriately in under the given heterogeneous velocity structure. Also the characteristics of the ground motion in an sedimentary basin such as the amplification, trapping, and focusing of the elastic wave energy are well represented. These results demonstrate the use of this simulation method will be helpful for modeling the ground motion of seismological and engineering purpose like earthquake hazard assessment, seismic design, city planning, and etc..

• Journal of Positioning, Navigation, and Timing
• /
• 제2권2호
• /
• pp.101-108
• /
• 2013

GPS is the most widely-used Positioning, Navigation, and Timing (PNT) system. Since GPS is an important PNT infrastructure, the vulnerability of GPS to signal jamming has received significant attention. Especially, South Korea has experienced intentional high-power jamming from North Korea for the past three years, and thus realized the necessity of a complementary PNT system. South Korea recently decided to deploy a high-power terrestrial navigation system, eLoran, as a complementary PNT system. According to the plan, the initial operational capability of the Korean eLoran system is expected by 2016, and the full operational capability is expected by 2018. As a necessary research tool to support the Korean eLoran program, an eLoran performance simulation tool for Korea is under development. In this paper, the received signal strength, which is necessary to simulate eLoran performance, from the suggested Korean eLoran transmitters is simulated with the consideration of effective ground conductivities over Korea. Then, eLoran signal-to-noise ratios are also simulated based on atmospheric noise data over Korea. This basic simulation tool will be expanded to estimate the navigation performance (e.g., accuracy, integrity, continuity, and availability) of the Korean eLoran system.

• 한국자동차공학회논문집
• /
• 제18권4호
• /
• pp.92-98
• /
• 2010

Virtual ground modeling is one of key topic for real-time vehicle dynamic simulation. This paper discusses about the virtual 3D road modeling process using parametric surface concept. General road data is a type of lumped position vector so interpolation process is required to compute contact of internal surface. The parametric surface has continuity and linearity within boundaries and functions are very simple to find out contact point. In this paper, the parametric surface formula is adopted to road modeling to calculate road hight. Position indexing method is proposed to reduce memory size and resource possession, and a simple mathematical method for contact patch searching is also proposed. The developed road process program is tested in dynamic driving simulation on off-road. Conclusively, the new virtual road program shows high performance of road hight computation in vast field of off-road simulation.