• 제목/요약/키워드: Efficiency calibration

검색결과 333건 처리시간 0.029초

Phantom를 이용한 Precision의 측정과 서로 다른 DEXA System의 BMD 교차보정의 유용성 (The Efficiency of BMD Cross-calibration for each different DEXA-System and Measurement of Precision used by Phantom)

  • 이승진;최유진;이평재;권영호;정은선;서길원;황승연
    • 대한방사선협회지
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    • 제30권1호
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    • pp.41-48
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    • 2004
  • To know the Difference of BMD value actually measured by the Hologic equipment and the Lunar equipment that is the latest machine due to the acknowledgement for the difference of value when the follow-up test was performed by other different equipment aft

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NAC Measurement Technique on High Parallelism Probe Card with Protection Resistors

  • Kim, Gyu-Yeol;Nah, Wansoo
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제16권5호
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    • pp.641-649
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    • 2016
  • In this paper, a novel time-domain measurement technique on a high parallelism probe card with protection resistors installed is proposed. The measured signal amplitude decreases when the measurement is performed by Needle Auto Calibration (NAC) probing on a high parallelism probe card with installed resistors. Therefore, the original signals must be carefully reconstructed, and the compensation coefficient, which is related to the number of channel branches and the value of protection resistors, must be introduced. The accuracy of the reconstructed signals is analyzed based on the varying number of channel branches and various protection resistances. The results demonstrate that the proposed technique is appropriate for evaluating the overall signal performance of probe cards with Automatic Test Equipment (ATE), which enhances the efficiency of probe card performance test dramatically.

지능형 변속 시스템을 위한 변속선도 보정기법 (Shift Map Calibration Method for Intelligent Transmission System)

  • 김종수;김성주;최우경;전홍태
    • 전자공학회논문지CI
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    • 제41권6호
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    • pp.55-60
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    • 2004
  • 결정된 변속선도에 의한 자동변속 패턴은 운전자에게 편리한 변속을 제공한다. 하지만, 운전자의 운전 성향이 개인마다 다양함으로 고정된 변속선도를 여러 운전자에게 동일하게 제공하는 것은 불만의 요소로 인식되고 있다. 이에, 본 논문에서는 운전자의 성향을 결정할 수 있는 입력을 이용한 학습 모듈을 설계하여 운전 성향을 판단하고자 한다. 판단된 운전 성향을 이용하여 변속선도를 조정함으로써 운전자의 의지에 부합되는 변속패턴을 제공하고자 한다. 실제 주행 시 얻은 데이터를 이용하여 제안된 모듈의 성능의 우수함을 보인다.

Gas Chromatograph에 의한 Arylmethy Halides의 정량 (Determination of Arylmethyl Halides by Gas Chromatograph)

  • 오도석;최호춘
    • 한국산업보건학회지
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    • 제4권1호
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    • pp.25-32
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    • 1994
  • Arylmethyl halides(benzyl chloride, BZYC; benzal chloride, BZYA; benzotrichloride, BZTC) and related compounds(benzyl alcohol, BZYA; benzoyl chloride, BZOC) were determined by GC using capillary column. Detailed results are as follows. 1. Stability In methanol benzotrichloride slowly transferred to benzoyl chloride by hydrolysis(ca. 7.5% for 5 days), but the others were stable. Therefore, benzotrichloride solution should be prepared just before analysis. 2. GC analysis Tenax-GC was used to absorbent and desorption solvents were $CCl_4$ and MeOH. Arylmethyl halides were analyzed within 7.5min without interference with related compounds. The calibration curve(ca. 15-80 ppm in soln), repeatability(n=10) and the desorption efficiency were good. Limit of detection by NIOSH method was about 0.003 ppm for arylmethyl halide, respectively. To analyze arylmethyl halides and related compounds in working places GC using capillary column is anticipated to be used effectively.

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서울전파천문대(SRAO) 6M 망원경의 ON-THE-FLY 관측 시스템 구축 (DEVELOPMENT OF ON-THE-FLY(OTF) OBSERVATION METHOD FOR SEOUL RADIO ASTRONOMY OBSERVATORY(SRAO) 6-METER TELESCOPE)

  • 강현우;변도영;박용선
    • 천문학논총
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    • 제20권1호
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    • pp.73-83
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    • 2005
  • On-The-Fly (OTF) observation method is developed for the efficient use of 6 M radio telescope at Seoul Radio Astronomy Observatory (SRAO). This technique, in which data and information of antenna position are recorded synchronously while driving a telescope regularly and rapidly across a field, provides more efficient use of telescope time and better calibration of the acquired data than the traditional point-to-point observation method does. For the realization of the method, we (1) added RT-Linux modules to the existing operating system, (2) replaced digital voltmeter with voltage-to-frequency converter, and (3) modified many SRAO observation programs. By observing Moon and G78.2+2.7 using this method and comparing them with previous observations, we verify the successful operation and efficiency of the OTF observation mode.

An efficent method of binocular data reconstruction

  • Rao, YunBo;Ding, Xianshu;Fan, Bojiang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제9권9호
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    • pp.3721-3737
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    • 2015
  • 3D reconstruction based on binocular data is significant to machine vision. In our method, we propose a new and high efficiency 3D reconstruction approach by using a consumer camera aiming to: 1) address the configuration problem of dual camera in the binocular reconstruction system; 2) address stereo matching can hardly be done well problem in both time computing and precision. The kernel feature is firstly proposed in calibration stage to rectify the epipolar. Then, we segment the objects in the camera into background and foreground, for which system obtains the disparity by different method: local window matching and kernel feature-based matching. Extensive experiments demonstrate our proposed algorithm represents accurate 3D model.

SUV - EPS 차량의 동시 시뮬레이션 기술 개발 및 시뮬레이션 통합 기술 개발 (Co-Simulation and Simulation Integration Technology Development for SUV Vehicle Equipped with Electric Power Steering (EPS))

  • B. C. Jang;Y. K. Eom
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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    • pp.472-475
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    • 2003
  • Electric Power Steering (EPS) mechanism has become widely equipped in passenger vehicle due to the environmental consciousness and higher fuel efficiency. This paper describes the development of co-simulation technique and simulation integration technique of EPS control system with dynamic vehicle model. A full vehicle model interacted with EPS control algorithm is concurrently simulated on a single bump road condition. Dynamic responses of vehicle chassis and steering system resulting from road surface impact are evaluated and compared with proving ground experimental data. The comparisons will show reasonable agreement on tie-rod load. rack displacement, handle-wheel torque and tire center acceleration. This developed simulation capability can be used for EPS performance evaluation and calibration as well as for vehicle handling performance integration and synthesis.

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환경부 토지피복 중분류 적용을 위한 L-THIA 모델 수정과 SCE-UA연계적용에 의한 금호강유역 비점오염 분포파악 (L-THIA Modification and SCE-UA Application for Spatial Analysis of Nonpoit Source Pollution at Gumho River Basin)

  • 김정진;김태동;최동혁;임경재;버나드엥겔;전지홍
    • 한국물환경학회지
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    • 제25권2호
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    • pp.311-321
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    • 2009
  • Long-Term Hydrologic Impact Assessment (L-THIA) was modified to improve runoff and pollutant load prediction for Korean watersheds with changes in land use classification and event mean concentration produced from observed data in Korea. The L-THIA model was linked with SCE-UA, which is one of the global optimization techniques, to automatically calibrate direct runoff. Modified L-THIA model was applied to Gumho River Basins to analyze spatial distribution of nonpoint source pollution. The results of model calibration during 1991~2000 and validation during 1981~1990 for direct runoff represented high model efficiency of 0.76 for calibration and 0.86 for validation. As a results of spatial analysis of nonpoint source pollution, the BOD was mainly loaded from urban area but SS, TN, and TP from agricultural area which is mainly located along the stream. Modified L-THIA model improve its accuracy with minimum imput data and application efforts. From this study, we can find out the L-THIA model is very useful tool to predict direct runoff and pollutant loads from the watershed and spatial analysis of nonpoint source pollution.

Dual Energy X-ray 흡수 영상의 분해를 통한 뼈 영역 추출 (Bone Region Extraction by Dual Energy X-ray Absorbtion Image Decomposition)

  • 권주원;조선일;안영복;노용만
    • 한국멀티미디어학회논문지
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    • 제12권9호
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    • pp.1233-1241
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    • 2009
  • 골다공증은 45세 이상의 여성 50% 이상이 갖고 있는 질환이다. 더욱이 질병의 증상을 환자가 느끼지 못하여 병을 심화시키기 때문에 조기 진단으로 골다공증을 예방하는 것이 중요하다. 이를 위해 골밀도(Bone Mineral Density)의 효과적인 측정을 위한 다양한 연구가 국내외적으로 수행되고 있다. 골밀도 측정을 위해서는 X-선 영상이 활용되고 있으며, 이 중에서 이중 에너지 X 선 흡수법(DEXA)을 이용하여 골밀도를 측정하는 방법은 많은 관심을 받고 있는 분야이다. DEXA 영상은 서로 다른 두 에너지준위의 X선으로부터 영상을 획득함으로써 생체조직의 중첩에 의한 잡음을 효과적으로 줄여 진단효과를 높이는데 유용하다. 하지만, DEXA 영상에서 골영역을 추출하기 위해서는 실험적으로 계수를 결정해야 하는 문제점이 있다. 본 논문에서는 두 에너지 흡수 영상에서 골영역을 추출하기 위해 실험적으로 결정하는 변수를 X-선 영상의 물리적 의미와 각 에너지에 반응하는 생체조직들의 감쇠상수 특성을 기반으로 분석하여 골영역을 효과적으로 검출하는 방법을 제안한다. 더불어 다양한 영상을 적용한 실험으로 제안한 알고리즘의 효율성을 확인하였다.

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SWAT 모형을 이용한 대청댐 유역의 기후인자에 따른 유출 및 유사량 민감도 평가 (Sensitivity Analysis of Climate Factors on Runoff and Soil Losses in Daecheong Reservoir Watershed using SWAT)

  • 예령;정세웅;이흥수;윤성완;정희영
    • 한국물환경학회지
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    • 제25권1호
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    • pp.7-17
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    • 2009
  • Soil and Water Assessment Tool (SWAT) was used to assess the impact of potential future climate change on the water cycle and soil loss of the Daecheong reservoir watershed. A sensitivity analysis using influence coefficient method was conducted for two selected hydrological input parameters and three selected sediment input parameters to identify the most to the least sensitive parameters. A further detailed sensitivity analysis was performed for the parameters: Manning coefficient for channel (Cn), evaporation (ESCO), and sediment concentration in lateral (LAT_SED), support practice factor (USLA_P). Calibration and verification of SWAT were performed on monthly basis for 1993~2006 and 1977~1991, respectively. The model efficiency index (EI) and coefficient of determination ($R^2$) computed for the monthly comparisons of runoffs were 0.78 and 0.76 for the calibration period, and 0.58 and 0.65 for the verification period. The results showed that the hydrological cycle in the watershed is very sensitive to climate factors. A doubling of atmospheric $CO_2$ concentrations was predicted to result in an average annual flow increase of 27.9% and annual sediment yield increase of 23.3%. Essentially linear impacts were predicted between two precipitation change scenarios of -20, and 20%, which resulted in average annual flow and sediment yield changes at Okcheon of -53.8%, 63.0% and -55.3%, 65.8%, respectively. An average annual flow increase of 46.3% and annual sediment yield increase of 36.4% was estimated for a constant humidity increase 5%. An average annual flow decrease of 9.6% and annual sediment yield increase of 216.4% was estimated for a constant temperature increase $4^{\circ}C$.