• Title/Summary/Keyword: 측정 정밀도 향상

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Cable Tension Force Management Using Vibration Method at Cable Stayed Bridge Construction Stages (진동법을 이용한 사장교 시공단계별 케이블 장력관리)

  • Park, Yeon-Soo;Cheon, Dong-Ho;Cheon, Yang-Bae;Kang, Kyoung-Koo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.9 no.4
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    • pp.127-134
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    • 2005
  • Design and construction of long-span bridge are recently increasing by development of computer technology. Specially, cable stayed bridge and suspension bridge having cable component are representative of long-span bridge may do. Therefore, this paper a present a methodology for cable tension force monitoring in cable-stayed bridge under construction using acceleration data acquired by the vibration method. To improve accuracy construction, all stay cables are measured, according to 4-step construction stage and change of temperature.

New Method of Volume Measurement for Reference Weights of a Pressure Balance Using a Gas Pycnometer (기체용적계를 이용한 분동식 압력계용 기준분동의 새로운 부피측정 방법)

  • Lee, Yong Jae;Lee, Woo Gab;Mohammed, Mohammed Abdurahman;Park, Yon-Kyu;Oh, Chae Yoon
    • Journal of the Korean Vacuum Society
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    • v.22 no.5
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    • pp.231-237
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    • 2013
  • New method of volume measurement for reference weights of a pressure balance using a gas pycnometer is proposed. The result of volume measurement of proposed method shows the uncertainties of approximately 0.2% at the level of confidence of 95% for reference weights in the ranges of 1 kg, 2 kg, and 5 kg. This measuring system consists of a sample chamber, an expansion chamber, a precision pressure gage, a precison thermometer, a vacuum pump, and helium as a medium gas. The measurement principle of this proposed method is based on Boyle's law. This method will contribute a reliability of the volume measurements of reference weights for a pressure balance to the national measurement standard.

Meaurement Algorithms for EDGE Terminal Performance Test (EDGE 단말기 성능 테스트를 위한 측정 알고리즘)

  • Kang, Sung-Jin;Hong, Dae-Ki;Kim, Nam-Yong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.12
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    • pp.2719-2730
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    • 2009
  • In this paper, we implement the measurement functionality for performance measurements of EDGE (Enhanced Data Rates for GSM Evolution) terminal by using software. Generally speaking, the receiving algorithms in normal MODEM cannot be used directly to a measurement system due to the lack of accuracy. Therefore, we propose a new receiver algorithm for precise EDGE signal measurements. In the proposed algorithm, 2-stage (coarse stage, fine stage) parameters estimation (symbol-timing, frequency offset, carrier phase) scheme is used. To improve the estimation accuracy, we increase the number of the received signal samples by interpolation. The proposed EDGE signal measurement algorithm can be used for verifying the hardware measurement system, and also can be used for the commercial systems through software optimization.

Development of guide for wrapping vegetables for smart precision agriculture based on IoT (IoT 기반 스마트 정밀농업을 위한 쌈 채소 포장용 가이드 개발)

  • Kwon, Kyu Sik;Park, No Chang
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2017.04a
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    • pp.144-144
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    • 2017
  • 쌈 채소 생산 및 유통의 효율성, 생산성 개선으로 경쟁력 향상을 위해 IoT 기반 스마트 저울과 쌈 채소전용 포장용 가이드를 개발 융합하여 안전하고 빠른 포장, 이동성 개선, 포장과 무게측정 동시 진행 및 출하량 자동측정으로 작업공정개선을 통해 최종적으로 생산성을 향상시킬 수 있는 제품을 개발하고자 한다. 1) 쌈 채소 포장용 가이드를 포함한 실시간 포장 무게 측정 장치 개발 ${\circ}$ 포장 박스와 관계없이 용이하게 사용할 수 있는 쌈 채소 포장용 가이드 개발 ${\circ}$ 실시간 포장 무게를 측정하여 출하 무게에 도달하였을 때 생산담당자에게 부저를 통해 신호전달 2) 생산패턴 분석을 통한 생산관리 애플리케이션 개발 ${\circ}$ 생산 패턴을 파악하여 실시간 생산량을 BLE 통신을 통해 관리자 스마트 폰으로 통지 ${\circ}$ 포장용 지그, 스마트 스케일, 이동체 1식으로 구성하여 용이하게 하우스 이동 3) 센서 디바이스 개발 ${\circ}$ 각종 센서(온도, 습도, 조도 등)의 디바이스를 활용하여 주위환경 데이터 수집 ${\circ}$ 스마트 폰 등을 활용한 콘텐츠 개발 및 노동복지 환경조성(작업환경 개선)

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A Study on Temperature Properties Analysis for Tension Measurement of Steel Cables Using Magnetic Sensor (자기센서에 의한 강재 케이블 장력측정에서 온도특성에 대한 연구)

  • Park, Hae-won;Ahn, Bong-young;Lee, Seung-seok;Park, Jeong-hak
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.13 no.2 s.54
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    • pp.181-188
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    • 2009
  • Measuring the tensile strength of steel cables used to support bridges is a critical inspection item in terms of the safety of a bridge. Today, cable tension is measured with the vibration method and loadcell. Recently, some advanced countries have conducted studies on measuring tension with magnetic method and are suggesting prospective results. Since there were no such studies ongoing in Korea, we began a study on measuring tension with magnetic method as we are undergoing researches to improve the precision of measurements. It is necessary to consider the influence for the magnetic field and the temperature of steel cables in tension measurement of magnetic method. In this paper, we tested an output characteristic of tension sensor according to temperature and deduced temperature compensation coefficient in the given magnetic field and applied the compensation coefficient to the tension measurement system in the lab. We analyzed and evaluated testing results for the output voltages of the tension sensor according to cable tensions.

관성센서 출력 측정을 위한 AF 변환기 교정기법

  • Kim, Jeong-Yong;Cho, Hyun-Chul;Roh, Woong-Rae;Choi, Hyung-Don;Cho, Gwang-Rae
    • Aerospace Engineering and Technology
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    • v.4 no.2
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    • pp.117-125
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    • 2005
  • Generally, the inertial navigation and guidance unit uses AF(Analog-to-Frequency) converters which convert analog signals into frequency signals to enhance a measurement accuracy of gyroscope and accelerometer outputs. The confidence level of AF converter is guaranteed by a prudential decision of calibration procedure and a performance of periodic calibration test. In this paper, we focus on the synchronous charge balance type AF converter which has a separate positive or negative current input and its calibration method is described. The calibration tests are classified into the scale factor error calibration and the bias calibration. These tests are automatically performed by the calibration program.

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A study on improving LSAST ambiguity resolution for CDGPS (CDGPS를 위한 LSAST 미지정수 추정기법 개선에 관한 연구)

  • Lee, Gi-Hun
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.34 no.5
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    • pp.74-80
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    • 2006
  • GPS, which has been opened to the public since the 1980's, uses the C/A code time of arrival to estimate the position, and measures the carrier doppler frequency to estimate the velocity. In development from the 1990's, DGPS has improved position accuracy by eliminating common errors and CDGPS has achieved cm-level position accuracy using carrier phase. In this paper, a modified LSAST ambiguity resolution method for CDGPS is proposed to improve reliability and computational efficiency. Also the test results of cm level relative positioning of a moving vehicle using single frequency GPS receivers are compared to INS position. This research result can be widely used for the development of high precision INS, unmanned autonomous driving, survey and mapping, etc.

Quality Assessment and Comparison of Several Radioimmunoassay Kits and Chemiluminescence Immunoassay Methods for Evaluating Serum Estradiol (혈중 Estradiol 농도 측정을 위한 여러 방사면역측정 검사키트 및 화학면역발광 검사법의 성능평가 및 상호비교)

  • Choi, Sung Hee;Noh, Gyeong Woon;Kim, Jin Eui;Song, Yoo Sung;Paeng, Jin Chul;Kang, Keon Wook;Lee, Dong Soo
    • The Korean Journal of Nuclear Medicine Technology
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    • v.19 no.1
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    • pp.72-80
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    • 2015
  • Purpose Serum estradiol ($E_2$) measurement is requested for diagnosing menstrual cycles, ovulation induction, infertility, and menopause. $E_2$ is measured using several methods and kits including radioimmunoassay (RIA) and chemiluminescece immunoassay (CLIA). The purpose of this study was to evaluate quality of these methods and to compare them with each other. Materials and Methods Seven radioimmunoassay kits and two CLIA methods were included in the analysis. Using standard samples and patient samples, intra-assay precision, inter-assay precision, correlation between other methods, sensitivity, and recovery rate were evaluated. Results For all tested kits and methods, coefficients of variance (CVs) of intra-assay precision test were 10.9~13.6% in low-level samples and less than 10% in medium and high-level samples. CVs of inter-assay precision test were 10.8~12.3% in low-level samples and less than 10% in medium and high-level samples with all tested kits and methods. Recovery rates were $92.7{\pm}12.4%$ for SIEMENS, $101.4{\pm}18.4%$ for DIAsource, $95.1{\pm}11.5%$ for AMP, $108.4{\pm}18.5%$ for BECKMAN COULTER, $104.2{\pm}13.5%$ for BECKMAN COULTER Ultra Sensitive, $101.3{\pm}11.6%$ for CIS Bio, and $93.1{\pm}13.2%$ for MP kits. Sensitivity was 7.5, 6.2, 5.7, 6.2, 5.3, 4.5, and 5.5 pg/mL for SIEMENS, DIAsource, AMP, BECKMAN COULTER, BECKMAN COULTER Ultra Sensitive, CIS Bio, and MP kits, respectively. The measurement by MP kit was slightly higher than those by other kits in low-level samples, and the measurement by E170 was slightly higher than those of other kits in medium and high-level samples. In the measurement of standard sample for external quality control, SIEMENS kit produced relatively lower values whereas E170, Architect, and MP kits produced relatively higher values compared with other kits. Conclusion All tested kits for $E_2$ measurement have satisfactory performance for clinical use. However, correlation between kits should be considered when test kits are to be changed, because some pairs of kits do not have correlations with each other.

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The Effect of Crystallization by Heat Treatment on Electromagnetic Interference Shielding Efficiency of Carbon Fibers (열처리 온도에 의한 구조 결정성이 탄소섬유의 전자파 차폐 성능에 미치는 영향)

  • Kim, Jong Gu;Chung, Choul Ho;Lee, Young-Seak
    • Applied Chemistry for Engineering
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    • v.22 no.2
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    • pp.138-143
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    • 2011
  • To investigate the electromagnetic interference shielding efficiency (EMI SE) property based on heat treatment effects of carbon fibers in various temperatures, the polyacrilonitrle-based carbon fibers were prepared by electrospinning method and treated at 1073, 1323, 1873 and 2573 K. The surface morphology of carbon fibers was investigated by using FE-SEM and the carbon crystallization was studied by Raman spectroscopy based on effects of reaction temperatures. The electrical conductivity was obtained by measuring the surface resistance with four probe method on carbon crystallization. The permittivity, permeability and EMI SE were investigated by using S-parameter in the range of 800~4500 MHz. In case of carbon fibers treated at 2573 K, the improved carbon crystallization was confirmed by Raman spectrum and the enhanced electrical conductivity showing 54.7 S/cm was also observed. The permittivity was dramatically improved by factor of 4 based on effect of high reaction temperature. Eventually, the highly improved EMI SE value was obtained showing around 41.7 dB.

A study on a fast measuring algorithm of wavefront for an adaptive optics system (적응광학시스템의 고속 파면측정 알고리즘에 대한 연구)

  • 박승규;백성훈;서영석;김철중;박준식;나성웅
    • Korean Journal of Optics and Photonics
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    • v.13 no.3
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    • pp.251-257
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    • 2002
  • The measuring resolution and speed for wavefronts are important to improve the performance of an adaptive optics system. In this paper, we propose a fast measuring algorithm with high resolution in the Shack-Hartmann wavefront sensor for an adaptive optics system. We designed ground isolated electrical devices whose differential data signals are used to control the deformable mirror and tip/tilt mirror for robust control. The conventional mass centroid algorithm in the Shack-Hartmann sensor to measure wavefront has been widely used and provided good measurement results. In this paper, the proposed fast measuring algorithm for measuring the wavefront combines the conventional mass centroid algorithm with a weighting factor. The weighting factor is a real value estimating the real center of mass in a wavefront spot image. This proposed wavefront measuring algorithm provided fast measurement results with high resolution from experimental tests.