• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.357-364
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• 2015

In this work, we investigate the quantum effects exhibited from ultra-thin GAA(gate-all-around) Nanowire FETs for Sub 14nm Technology. We face designing challenges particularly short channel effects (SCE). However traditional MOSFET SCE models become invalid due to unexpected quantum effects. In this paper, we investigated various performance factors of the GAA Nanowire FET structure, which is promising future device. We observe a variety of quantum effects that are not seen when large scale. Such are source drain tunneling due to short channel lengths, drastic threshold voltage increase caused by quantum confinement for small channel area, leakage current through thin gate oxide by tunneling, induced source barrier lowering by fringing field from drain enhanced by high k dielectric, and lastly the I-V characteristic dependence on channel materials and transport orientations owing to quantum confinement and valley splitting. Understanding these quantum phenomena will guide to reducing SCEs for future sub 14nm devices.

• Proceedings of the Safety Management and Science Conference
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• 2001.11a
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• pp.169-174
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• 2001

IMF이후 건설 물량은 감소하고 있는 경향이나 재해율은 그다지 감소하지 않고 있고 여전히 중대재해는 계속 발생하고 있는 추세이며, 건설업체에서는 안전관리에 대한비용을 더욱 아끼려 하고 있어 비용절감을 위해 재해예방을 위한 안전시설 비용이나 안전활동 비용을 투자하지 않고 있다. 따라서, 본 연구는 중·소규모 건설현장 안전점검의 실태를 조사 분석하여 문제점을 도출하고 효율적 운영방안을 제시하는 것으로 하였다 현행 안전점검의 실태조사를 위하여 안전점검의 관계담당자인 전국의 노동부 지방노동관서 근로감독관, 한국산업안전의 각 지역본부 및 지도원 기술직원, 안전점검대상 건설현장 관계자에게 각각 설문 조사지를 배부하여 실태를 조사하고 분석하였으며, 또한 노동부의 최근 년도인 1999년, 2000년도의 재해발생통계 및 안전점검실적 자료, 대한건설협회의 최근 년도별 건설공사 수주금액, 공사규모별 현황 및 외국의 건설현장 안전점검사례를 수집하고 분석하였다. 이러한 실태조사 등 수집된 자료분석 및 각종 참고문헌 연구를 통하여 안전점검의 대상현장을 선정하는 기준과 위반사항에 대한 행정 및 사법조치 기준에 대한 문제점을 제시하고 이러한 문제점에 대하여 효율적인 개선대책을 제시하였다.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.39.2-39.2
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• 2016

The central regions of barred-spiral galaxies contain interesting gaseous structures such as dust lanes located at the leading side of the bar and nuclear rings that are sites of intense star formation. Our previous studies showed how gas structures form under the influence of a non-axisymmetric bar potential and temporal/spatial behavior of the star formation in nuclear rings. However, previous works were limited to 2-dimensional infinitesimally-thin, unmagnetized and isothermal disks. To study effects of cooling/heating, vertical motions of gas structures and magnetic field, we use Mesh-Free magneto-hydrodynamic simulation code GIZMO. We find that temporal variations of the star formation rates in the nuclear ring in the three-dimensional model are overall similar those in the previous two-dimensional results, although the former shows more violent small-scale fluctuations near the early primary peak. We will present our recent results about evolution of gaseous structures and star formation rate compare with results of previous studies.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.247-249
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• 1999

This paper presents the design of a small scale High Tc superconducting power transformer. In the design of the transformer, BSCCO-2223 tape was considered as the conductor. Double pan cake winding was adopted in order to easy the construction of the winding and to lessen the leakage reactance of the transformer. Numerical calculation was used to decide the arrangement of the double pan cake winding. Estimation of the AC loss, magnetizing loss and self field loss, in the superconducting winding and the iron loss in the core were given.

• KSBB Journal
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• v.30 no.1
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• pp.1-10
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• 2015

Nanomaterial-based artificial enzymes (Nanozymes) have attracted recent attention because of their unique advantageous characteristics such as excellent robustness and stability, low-cost production by facile scale-up, and longterm preservation capability that are critically required as an alternative to natural enzymes. These nanozymes exhibit natural enzyme-like activity, and they have been applied to diverse kinds of detection methods for disease-associated biomolecules such as DNAs, proteins, cells, and small molecules including glucose. To highlight the progress in the field of disease diagnostics using nanozyme, this review discusses many nanozyme-based detection methods categorized by the types of target biomolecules. Finally, we address the current challenges and perspectives for the widespread utilization of nanozyme-based disease diagnostics.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2265-2267
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• 2005

We present detailed studies of externally applicable UHF PD sensors for a metal covered epoxy barrier with a small opening of epoxy injection-hole. The sensors were attached at the surface of injection hole of a metal covered epoxy barrier. 3-Dimensional electro magnetic simulations were performed to analyze electric-field distribution of the GIS and epoxy barrier with injection hole. Sensor structures were designed and analyzed using the 3-D EM simulator then fabricated for experimental verification. Sensor performance was measured in terms of spectral response and detected peak power. Real scale GIS and epoxy barriers were used to test and measure various aspect of performance of the sensors.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.02a
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• pp.73-81
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• 2004

National Geographic Information Institute (NGII) in Korea, through National Geographic Information System (NGIS) Program, has prepared to generate and disseminate digital elevation data for Korea. This is a pilot research to propose a policy for generation, maintenance, and supply of Korea Digital Elevation Data (KDED). Customer demands for accuracy and resolution of DEM was surveyed through questionnaire. In order to investigate the quality, the technical efficiency and the production cost, a tentative DEM in a small test site was generated based on digital topographic maps (original paper map scale 1 :5,000), analytical plotter, and LIDAR. Accuracy standard for KDED was derived based on source data and generation methods. As results of this research, we recommend uniformly spaced grid model for KDED. Its preferable grid space is 5m in urban and its vicinity; and 10m in field and mountainous area. LIDAR has been valuated as a proper KDED generation method fulfilling customers demand for the accuracy.

• Smart Structures and Systems
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• v.23 no.2
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• pp.123-139
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• 2019

Impact forces induced by external object collisions can cause serious damages to civil engineering structures. While accurate and prompt identification of such impact forces is a critical task in structural health monitoring, it is not readily feasible for civil structures because the force measurement is extremely challenging and the force location is unpredictable for full-scale field structures. This study proposes a novel approach for identification of impact force including its location and time history using a small number of multi-metric observations. The method combines an augmented Kalman filter (AKF) and Genetic algorithm for accurate identification of impact force. The location of impact force is statistically determined in the way to minimize the AKF response estimate error at measured locations and then time history of the impact force is accurately constructed by optimizing the error co-variances of AKF using Genetic algorithm. The efficacy of proposed approach is numerically demonstrated using a truss and a plate model considering the presence of modelling error and measurement noises.

• The Journal of Engineering Geology
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• v.18 no.1
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• pp.17-26
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• 2008

In this study, the design method of slope reinforced by the earth retention systems were systematically developed, and the flow chart of design procedure fur each system were constructed to design the slope rationally. The proposed design method is composed of 5 steps such as field condition investigation step, slope design step, landslide occurrence prediction step, slope failure scale estimation step and reinforcement countermeasure selection step. The quantitative standard of slope failure scale was established based on the arrangement of various overseas standards which is estimating the slope failure, and the analysis of slope failure scale which is occurred in the country. The slope failure scale is classified into three categories the small scale of slope failure is less than $150m^3$ of slope failure volume, the middle scale of slope failure is from $150m^3$ to $900m^3$ and the large scale of slope failure is more than $900m^3$. The earth retention system could be selected by the proposed slope failure scale based on the slope failure volume. Meanwhile, the design methods of earth retention system such as piles, soil nails and anchors were developed. The optimal countermeasure for slope stability could be proposed using above design methods.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.40.3-41
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• 2017

Korea Astronomy and Space Science Institute The observation of particles and waves using a single satellite inherently suffers from space-time ambiguity. Recently, such ambiguity has often been resolved by multi-satellite observations; however, the inter-satellite distances were generally larger than 100 km. Hence, the ambiguity could be resolved only for large-scale (> 100 km) structures while numerous microscale phenomena have been observed at low altitude satellite orbits. In order to resolve those spatial and temporal variations of the microscale plasma structures on the topside ionosphere, SNIPE mission consisted of four (TBD) nanosatellites (~10 kg) will be launched into a polar orbit at an altitude of 700 km (TBD). Two pairs of satellites will be deployed on orbit and the distances between each satellite will be from 10 to 100 km controlled by a formation flying algorithm. The SNIPE mission is equipped with scientific payloads which can measure the following geophysical parameters: density/temperature of cold ionospheric electrons, energetic (~100 keV) electron flux, and magnetic field vectors. All the payloads will have high temporal resolution (~ 16 Hz (TBD)). This mission is planned to launch in 2020. The SNIPE mission aims to elucidate microscale (100 m-10 km) structures in the topside ionosphere (below altitude of 1,000 km), especially the fine-scale morphology of high-energy electron precipitation, cold plasma density/temperature, field-aligned currents, and electromagnetic waves. Hence, the mission will observe microscale structures of the following phenomena in geospace: high-latitude irregularities, such as polar-cap patches; field-aligned currents in the auroral oval; electro-magnetic ion cyclotron (EMIC) waves; hundreds keV electrons' precipitations, such as electron microbursts; subauroral plasma density troughs; and low-latitude plasma irregularities, such as ionospheric blobs and bubbles. We have developed a 6U nanosatellite bus system as the basic platform for the SNIPE mission. Three basic plasma instruments shall be installed on all of each spacecraft, Particle Detector (PD), Langmuir Probe (LP), and Scientific MAGnetometer (SMAG). In addition we now discuss with NASA and JAXA to collaborate with the other payload opportunities into SNIPE mission.