• 한국철도학회논문집
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• 제13권5호
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• pp.488-492
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• 2010

과거부터 고속전철 및 집전시스템과 같은 핵심 주요 시스템에 대한 성능을 검증하기 위한 정교한 시험방법과 평가절차는 국내외의 전문가들을 통해 연구되어져 왔다. 판토그라프의 접촉력 측정 하중센서는 판토그라프의 특성에 따라 특수제작이 필요하다. 본 논문에서는 판토그라프와 가선시스템 간의 상호작용 특성을 평가하기 위한 항목인 접촉력을 측정하는 방법을 개선하기 위하여 개발된 스트레인 게이지 내장형 하중센서를 소개하고자 한다. 판토그라프에 직접 설치하여 수행한 정적 및 동적 검증의 결과는 매우 신뢰성을 가지고 있어 향후 고속전철용 판토그라프의 보다 효율적인 집전특성을 평가하기 위한 측정시스템의 일부로 활용될 수 있을 것이다.

• 한국진공학회지
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• 제7권1호
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• pp.1-4
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• 1998

이온 펌프의 중심에 네그(Non-Evaporable Getters)가 삽입된 새로운 조합 펌프를 사용하여 극고진공 시스템을 구현하였다. 진공 용기는 터보 분자 펌프만으로도 극고진공에 성공하였던, $450^{\circ}C$에서 잘 산화된 304 스테인레스 스틸 쳄버를 사용하였다. 시스템의 압력은 Leybold사의 EXG(Extractor Gauge)로 측정하였으나, 본 실험에서의 최고 진공도는 이미 그 게이지의 측정 한계인 1~$2\times10^{-12}$torr범위를 훨씬 지나 게이지 지시가 $-0\times10^{-12}$torr를 읽교 있는 극고진공에 도달해 있었다. 이는 효과적인 네그 활성화로 수소 가스에 대한 배기 속도 를 크게 향상시켜준 결과라 볼 수 있다. 또한 본 실험은 극고진공 표면 분석 장치의 실현 가능성을 시사해주는 것으로, 앞으로의 초미세 표면 과학에 있어서 새로운 장을 열어줄 것 으로 기대된다.

• 센서학회지
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• 제12권5호
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• pp.199-204
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• 2003

본 논문에서는 Ta-N 스트레인게이지를 이용한 극한 환경용 세라믹 박막형 압력센서의 제작 및 특성에 관하여 연구하였다. 압력감지부로 Ta-N 스트레인게이지를 사용하였으며, SDB(Si-wafer Direct Bonding)와 전기화학적 식각정지법을 이용하여 매몰 cavity를 가지는 저가격 고수율의 Si 박막 다이어프램을 제작하였다. 또한, 실리콘 박막 다이어프램상에 박막형 스트레인게이지를 형성하여 세라믹 박막형 압력센서를 제작하였다. 제작된 세라믹 박막형 압력 센서는 기존의 스트레인 게이지를 이용한 로드셀에 비해서 온도특성이 우수하고 재현성, 소형화, 집적화 및 저가격화가 가능하기 때문에 고온, 고압 등의 각한 환경에서도 사용이 가능할 것으로 기대된다.

• 대한치과교정학회지
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• 제21권2호
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• pp.287-307
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• 1991

This study aimed at examining speech defects of openbite patients, which were analized in terms of formant frequency for vowels and word pronunciation length for consonants. In addition, the upper and lower lip (perioral m.) activity was tested by the EMG. The tongue force was measured by the strain gauge, and the speech discrimination test was carried out. One experimental group and one control group were used for this study and they were respectively composed of six female openbite patients and six normal-occlusion females. Eight monophthongs, two fricatives and two affricatives were chosen for speech analysis. Speeches of the above-mentioned groups were recorded and then analized by the ILS/PC-1 software. Four hundred most frequently used monosyllables were also chosen for discrimination score. Openbite patients showed the following characteristics: 1. Abnormality in case of /a/, $/\varepsilon/$, /e/, /i/ $F_2$ and /e/, /a/ $F_1$. 2. Significantly elongated length in their pronunciation of /h/ and $/C^h/$ and somewhat elongated length also in their pronunciation of /s/ and /c/. 3. Significant upper lip activity according to the EMG test during pronunciation of the bilabial consonants. 4. Relatively weak tongue force according to the strain gauge measurement. 5. According to the speech discrimination test, high rate of misarticulation in case of (a) initial /p/ /s'/ and /ts'/, (b) /a/,$/\varepsilon/$,/e/,/je/,/o/, $/\phi/$,/jo/,/u/,/we/, and /i/ (c) final (equation omitted).

• 한국의상디자인학회지
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• 제11권2호
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• pp.43-53
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• 2009

The purpose of this study is to show inherent and differentiated beauty by designing costume knitwear using Dancho patterns representing peculiar beauty, thus expressing free and convenient knitwear in the modern sense for women with the image of reasonableness and elegance, proposing knit design using high-class materials for satisfying the demand for the highest. With regard to expression technique of works, I selected computer Jacquard method to indicate effective comparison effect of expression material and made expression with $12{\sim}14$ gauge as base by using computer knitting machine. Through above-mentioned research process and design using Knit CAD system, I obtained following conclusion. First, it is possible to express variously and widely traditional patterns by making the most of the beauty of the orient and by recomposing the patterns of plant patterns representing "feminine image". Second, it is possible to widely represent the sense you can feel from knit by expressing variously diversity of knit structure and Jacquard knitting structure and gauge. Finally, it is possible to express designs more freely and imaginably by using computer Knit CAD system instead of actual knitting of various knit expression technique and materials application.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 가을 학술발표회 논문집
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• pp.397-404
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• 1999

It is essential to measure load transfer mechanism of pile to check the appropriateness of assumptions made for design purpose and to continuously monitor the behavior of pile foundation. Through many attempts to monitor the behavior of super-structure in civil engineering area using several optical fiber sensors have been made, application of optical fiber sensor technology on pile foundation has not been tried up to now. Load transfer of model piles during compression loading was measured by optical fiber sensors and compared with the measurement by strain gauges. Fiber Bragg Grating(FBG) sensor system was used since it has many advantages, such as easy multiplexing, high sensitivity, and simple fabrication. Besides the model pile tests, uniaxial tension test of steel bar and compression tests of mortar specimen were carried out to evaluate the performance of FBG sensors in embedded environments. The shift of refilming wavelength due to the strain in FBG sensor is converted to the strain at sensor location and the dependence between them is 1.28 pm/${\mu}$ strain. FBG sensors embedded in model pile showed a better survivability than strain gauges. Measured results of load transfer by both FBG sensors and strain gauges were similar, but FBG sensors showed a smoother trend than those by strain gauge. Based on the results of model pile test, it was concluded that the use of FBG sensor for strain measurement in pile has a great potential for the analysis of pile load transfer.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.744-747
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• 2006

The sea level of the Java Sea is reproduced using HYbrid Coordinate Ocean Model (HYCOM) setting up in the horizontal grid from $100^{\circ}E$ to $125^{\circ}E$ and from $10^{\circ}S$ to $8^{\circ}N$. The model is initialized by ocean temperature and salinity profiles from Levitus 1998 and forced by the atmospheric field derived from NCEP reanalysis. In this research HYCOM is applied to explain the El $Ni{\tilde{n}}o$ Southern Oscillation (ENSO) impacts on the sea level of the Java Sea. The monthly tide gauge sea level data are produced based on hourly sea level data from 1993 to 1997. Altimeter sea level data are based on weekly merged products between TOPEX/Poseidon and ERS absolute dynamic topography (ADT). The simulated sea level both HYCOM and ADT agree well with the tide gauge sea level. The sea level of the Java Sea is high during the La $Ni{\tilde{n}}a$ period and low during the El $Ni{\tilde{n}}o$ period.

• Journal of Mechanical Science and Technology
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• 제17권5호
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• pp.629-636
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• 2003

This paper introduces the developed geometry PIG (Pipeline Inspection Gauge), one of several ILI (In-Line Inspection) tools, which provide a full picture of the pipeline from only single pass, and has compact size of the electronic device with not only low power consumption but also rapid response of sensors such as calipers, IMU and odometer. This tool is equipped with the several sensor systems. Caliper sensors measure the pipeline internal diameter, ovality and dent size and shape with high accuracy. The IMU (Inertial Measurement Unit) measures the precise trajectory of the PIG during its traverse of the pipeline. The IMU also provide three-dimensional coordination in space from measurement of inertial acceleration and angular rate. Three odometers mounted on the PIG body provide the distance moved along the line and instantaneous velocity during the PIG run. The datum measured by the sensor systems are stored in on-board solid state memory and magnetic tape devices. There is an electromagnetic transmitter at the back end of the tool, the transmitter enables the inspection operators to keep tracking the tool while it travels through the pipeline. An experiment was fulfilled in pull-rig facility and was adopted from Incheon LT (LNG Terminal) to Namdong GS (Governor Station) line, 13 km length.

• 디지털산업정보학회논문지
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• 제8권4호
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• pp.1-11
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• 2012

This paper is the study on the development of a torque precision measuring system using the curve fitting algorithm. This system can be divided into the hardware part and the software part. The hardware part consists of the main base board, the DAQ(Data Aquisition) board and Calibration parts. The software part consists of the software filter module and the curve fitting algorithm module. We have tested the torque transducer including the strain gauge for 200 Nm range and have analyzed the data acquired with the curve fitting algorithm by using this system. The DAQ board converts the electric signal induced by the transducer to the digital value precisely by using the shunt calibration procedure. The main board including the curve fitting algorithm calculates the exact digital torque value by using the digital value from the DAQ board. In this study, we confirmed that the result of the appropriate high-order power-series polynomial function is more accurate than the result of the low-order power-series polynomial through the system.

• 대기
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• 제28권3호
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• pp.273-289
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• 2018

This paper evaluates daily precipitation products from Integrated Multisatellite Retrievals for Global Precipitation Measurement (IMERG), Tropical Rainfall Measuring Mission Multisatellite (TRMM) Precipitation Analysis (TMPA), and the Climate Prediction Center Morphing Method (CMORPH), validated against gauge observation over South Korea and gauge-based analysis data East Asia during one year from June 2014 to May 2015. It is found that the three products effectively capture the seasonal variation of mean precipitation with relatively good correlation from spring to fall. Among them, IMERG and TMPA show quite similar precipitation characteristics but overall underestimation is found from all precipitation products during winter compared with observation. IMERG shows reliably high performance in precipitation for all seasons, showing the most unbiased and accurate precipitation estimation. However, it is also noticed that IMERG reveals overestimated precipitation for heavier precipitation thresholds. This assessment work suggests the validity of the IMERG product for not only seasonal precipitation but also daily precipitation, which has the potential to be used as reference precipitation data.