• Journal of the Korean Geophysical Society
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• v.8 no.1
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• pp.7-14
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• 2005

Early detection in real-time response of slope movements ensures tremendous saving of lives and repair costs from catastrophic disaster. Therefore, it is essential to constantly monitor the performance and integrity of slope-stabilizing structures such as Rock bolt, Nail and Pile during or after installation. We developed a novel monitoring system using Fiber Bragg Grating (FBG) sensor. It's advantages are highly sensitivity, small dimension and electro-magnetic immunity. capability of multiplexing, system integrity, remote sensing - these serve real-time health monitoring of the structures. Real-time strain measurement by the signal processing program is shown graphically and it gives a warning sound when the monitored strain state exceeds a given threshold level so that any sign of abnormal disturbance on the spot can be easily perceived.

• Journal of the Korean Geophysical Society
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• v.8 no.1
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• pp.39-43
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• 2005

For the calculation of internal stability, the hypothesis in conventional design is on the basis of two distinct zones, which are 'active zone' and 'passive zone'. This means that there is an abrupt discontinuous transition from active to passive states across a potential failure line. The existence of a discontinuity of this nature appears physically unreasonable, especially from kinematic considerations. A series of pull-out model tests was undertaken from a wall being rotated about the toe to find the strain istribution mobilized from near the wall face into the deep, stable zone through the centre plane. With this finding of transition zone, the objective of study is aiming at identifying the likely effect of this zone in designing method by comparing with the prevailing design method.

• Korean Journal of Soil Science and Fertilizer
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• v.42
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• pp.212-237
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• 2009

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.7A
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• pp.709-716
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• 2006

본 논문에서는 무선 센서 네트워크의 다양한 응용 환경 및 상/하향 트래픽 스트림의 특성에 따라 유연하게 적용할 수 있는 새로운 매체접근제어 프로토콜을 제안한다. HiPERMAC(Hierarchically-Paired Evolutionary Radio MAC)이라고 불리는 제안 매체접근제어방식은 다양한 클러스터링 방식에 의하여 구축된 다 계층 (Hierarchical) 네트워크에서 별도의 대역 확산 전송방식이나 다수의 주파수 채널을 사용하지 않고, 단 2개의 시간 구간을 공간적으로 재활용하여 N 계층의 개별적인 통신이 가능한 구조를 제공한다. 즉, 제안방식은 단일 주파수 개념을 이용하여 계층화된 우선 센서 네트워크를 계층적 이중화(Hierarchically-Paired)하고 이때 발생하는 클러스터 간 상호 간섭의 요인들을 시간 및 공간적으로 분리하여 망 확장성과 자원 효율성을 극대화 하는 새로운 매체접근 제어 방식 이다.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.952-954
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• 2003

This paper deals with design of Synchronous Reluctance Motor with conventional laminated rotor for driving an air conditional compressor in a vehicle. To design both stator and rotor, design parameters, such as laminated axial length, rotor diameter, resistance and inductance are considered. The design variables are selected to get the highest power by analyzing the characteristics. The current angle in which torque is maximum is accomplished by finite element method(FEM).

• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.274-276
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• 2000

Recently, the demands of the ultra-precision stage system, such as wafer stepper stages for photolithography, are increasing in the field of manufacturing and test equipment. Since the mechanical elements which convert rotational motion into translational introduce backlash and elasticity in the system, better performance of the drive could be achieved by the linear BLDC motor with appropriate servo control. The analytical design and the FEM analysis about linear BLDC motor is described in this paper. The performance of the servo-drive system will be evaluated through the comparison of results between the designed data and the measured data in the future.

• Economic and Environmental Geology
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• v.24 no.3
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• pp.301-308
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• 1991

Four Tertiary basins are distributed on the eastern coast of the southern Korean Peninsula, that is, Bugpyeong, Yeonghae, Pohang and Yangnam basins from north to south. The Yangnam and Pohang basins are the largest ones and have been well studied on their stratigraphies, paleoenvironments and geologic ages, and their tectonic history is representative on the tectogenesis of the Tertiary basins of the southern Korean Peninsula. The geologic events occurred in the Yangnam and Pohang basins from the Early-Middle Eocene through the Middle Miocene suggest that the Yangnam and Pohang basins resulted from the volcanism and rifting caused by the uprising magma, that is, by the diapiric tectogenesis.

• Progress in Superconductivity and Cryogenics
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• v.12 no.1
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• pp.17-21
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• 2010

In the case of designing superconducting power apparatuses using the second generation high temperature superconducting wire, it is necessary to have a tape-splicing technique to achieve low splice resistance between coated conductor (CC) tapes. In this paper, an experimental splice method between YBCO CC tapes is proposed for a coil application. Splices were performed with a 37Pb-63Sn solder. YBCO samples were fabricated with various pressures and cooling rates. Joint resistances of the spliced samples of jointed YBCO CC tapes were measured and evaluated from V-I curves. In addition, optical micrographs were obtained to analyze the cross sectional microstructure of jointed samples.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.369-372
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• 2011

양 방향성 필터는 이미지표면 평탄화와 잡음제거에 좋은 성능을 보이지만 특유의 연산 복잡도로 인하여 연산 시간이 오래 걸린다는 단점이 존재한다. 따라서 본 논문에서는 고도의 병렬수행을 바탕으로 하는 그래픽연산장치(GPU)에 적합하도록 수정된 효율적인 양 방향성 필터를 NVIDIA 의 CUDA 를 사용하여 GTX 285 GPU 에서 구현하였다. 영상의 전 영역을 참조하는 대신 인접하고 연속된 영역으로의 근사화, 적은 메모리 사용량, 빠른 접근속도를 가지며 충돌이 최소화된 공유메모리 버퍼, Warp 를 고려한 병합된 메모리 접근방법을 바탕으로 병렬화 하였다. 그 결과, 같은 방식의 순차실행 알고리즘 대비 최소 약 34 배에서 최대 약 76 배의 속도 개선과 30dB 내외의 PSNR 을 갖는 양 방향성 필터를 구현할 수 있었다.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2102-2107
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• 2007

GSHP systems are used for air-conditioning systems in commercial buildings, schools, and factories because of low operating and maintenance costs. These systems use the earth as a heat source in heating and a heat sink in cooling mode. Ground heat exchangers are classified by a horizontal and vertical type according to the installation method. Vertical type is usually constructed by placing small diameter high density polyethylene tube in a vertical borehole. Vertical tube sizes range from 20 to 40 mm nominal diameter. Borehole depth range between 100 and 200 m depending on local drilling conditions and available equipment. In this study, to evaluate the performance of single u-tube with bentonite grouting, single u-tube with broken stone grouting and double u-tube bentonite grouting of vertical ground heat exchangers, test sections are buried on the earth and experimental apparatus is installed. Therefore the heat transfer performance and pressure loss of these are estimated.