• Journal of the Optical Society of Korea
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• 제19권4호
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• pp.415-420
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• 2015

A novel method to measure the scale factor for the all-optical atomic spin inertial measurement device (ASIMD) is demonstrated in this paper. The method can realize the calibration of the scale factor by a self-consistent method with small errors in the quiescent state. At first, the matured IMU (inertial measurement unit) device was fixed on an optical platform together with the ASIMD, and it has been used to calibrate the scale factor for the ASIMD. The results show that there were some errors causing the inaccuracy of the experiment. By the comparative analysis of theory and experiment, the ASIMD was unable to keep pace with the IMU. Considering the characteristics of the ASIMD, the mismatch between the driven frequency of the optical platform and the bandwidth of the ASIMD was the major reason. An all-optical atomic spin magnetometer was set up at first. The sensitivity of the magnetometer is ultra-high, and it can be used to detect the magnetization of spin-polarized noble gas. The gyromagnetic ratio of the noble gas is a physical constant, and it has already been measured accurately. So a novel calibration method for scale factor based on the gyromagnetic ratio has been presented. The relevant theoretical analysis and experiments have been implemented. The results showed that the scale factor of the device was $7.272V/^{\circ}/s$ by multi-group experiments with the maximum error value 0.49%.

• 대한안전경영과학회지
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• 제10권2호
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• pp.217-223
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• 2008

Measurement is used for evaluation of product or process exactly. If it couldn't measured correctly, Quality-cost must be raised and it would be hard to improve product quality. So, this study suggests improvement guide line for the multilateral problems of measuring instrument operation based on the investigation of 157 small and medium-sized enterprises in February, 2008. To use inspection gig correctly, man who treat it must be accustomed with the structure, the performance, the method. The inspection gig is selected properly for the measurement goal. If not, results couldn't be correctly or wasted time, efforts, and costs. When selecting a inspection gig, the locating, the clamping, and the efficiency must be considered.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2003년도 추계종합학술대회
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• pp.311-314
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• 2003

본 논문은 PC를 기반으로 한 오류신호 보정기능을 가진 가상계측 제어시스템을 기술한다. 제안된 시스템은 주요소 축 분석법에 의한 오차신호 보정 알고리즘과 16bit RISC 머신을 사용한 센서제어보드, 부착된 센서에 따라 자동 조정되는 PC측의 GUI 인터페이스로 구성되어 있다. PC와 센서제어보드 사이에는 타른 통신을 보장하기 위하여 USB 통신 시스템 모듈이 설계 제작되어 사용되었다. 제안된 시스템의 효용성을 입증하기 위하여 제작된 8개의 CDs 센서가 부착된 태양추적장치에 적용되어 시험되었다.

• Current Optics and Photonics
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• 제2권6호
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• pp.519-524
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• 2018

We propose a transverse load sensor with reconfigurable measurement accuracy based on a microwave photonic filter in the $K_u$ band, incorporating a polarization-maintaining fiber Bragg grating. A prototype sensor with a reconfigurable measurement accuracy tuning range from 6.09 to 9.56 GHz/(N/mm), and corresponding minimal detectable load range from 0.0167 to 0.0263 N/mm, is experimentally demonstrated. The results illustrate that up to 40% manufacturing error in the grating length can be dynamically calibrated to the same corresponding measurement accuracy for the proposed transverse load sensor, by controlling the semiconductor optical amplifier's injection current in the range of 154 to 419 mA.

• Current Optics and Photonics
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• 제4권1호
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• pp.1-8
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• 2020

We research a system of compressed-sensing computational ghost imaging (CSCGI) based on the intensity fluctuation brought by turbulence. In this system, we used the gamma-gamma intensity-fluctuation model, which is commonly used in transmission systems, to simulate the CSCGI system. By setting proper values of the parameters such as transmission distance, refractive-index structure parameter, and sampling rates, the peak signal-to-noise ratio (PSNR) performance and bit-error rate (BER) performance are obtained to evaluate the imaging quality, which provides a theoretical model to further research the ghost-imaging algorithm.

• Journal of Biosystems Engineering
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• 제35권6호
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• pp.443-449
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• 2010

A machine vision-based instrument to measure a droplet size spectrum of a spray nozzle was developed and tested to evaluate its accuracy on measuring spray droplet sizes and classifying nozzle sizes. The instrument consisted of a machine vision, light emitting diode (LED) illumination and a desktop computer. The illumination and machine vision were controlled by the computer through a C++ program. The program controlled the machine vision to capture droplet images under controlled illumination, and processed the droplet images to characterize the droplet size distribution of a spray nozzle. An image processing algorithm was developed to improve the accuracy of the system by eliminating random noise and out-of-focus droplets in droplet images while measuring droplet sizes. The instrument measured sizes of the three different balls (254.0, 497.8 and $793.8\;{\mu}m$) and the measurement ranges were $241.2-273.6\;{\mu}m$, $492.9-529.6\;{\mu}m$ and $800.8-824.1\;{\mu}m$ for 254.0-, 497.84- and $793.75-\;{\mu}m$ balls, respectively. Error of the measured droplet mean was less than 3.0 %. Droplet statistics, $D_{V0.1}$, $D_{V0.5}$ and $D_{V0.9}$, of a reference nozzle set were measured, and droplet size spectra of five spray nozzles covering from very fine to extremely coarse were measured to classify spray nozzle sizes. Ninety percent of the classification results of the instrument agreed with manufacturer's classification. A comparison study was carried out between developed and commercial instruments, and measurement results of the developed instrument were within 20 % of commercial instrument results.

• 대한방사선기술학회지:방사선기술과학
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• 제25권2호
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• pp.71-75
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• 2002

검출능력이 우수하고 가격이 저렴하며 소형으로 제작할 수 있는 반도체검출기 중에서도 광전소지인 포토다이오드를 이용하였는데 이 소자는 특정표면이 입사광에 대하여 반응을 나타내는 소자인데 광 강도가 증가함에 따라 저항이 감소하는 특성을 이용하여 방사선 검출기를 제작하였다. 제작된 측정기는 접속식 측정기에 의해 검사치를 측정하여 기준치를 정하고 기존의 비접속형 측정기를 이용하여 제작된 비접속형 측정기와 정확성을 비교 검토하였다. 비교 결과 3가지 측정기의 모든 측정치가 기준치 범위에 속하였으며 정밀도를 분석하기 위하여 백분율 평균오차의 평균치를 구하였는데 기준측정기의 백분율평균오차의 평균치가 -0.02이고 비교측정기가 -0.22, 제작한 측정기가 0.17이었다.

• Journal of electromagnetic engineering and science
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• 제1권2호
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• pp.139-145
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• 2001

In this paper, a coaxial sample holder is proposed with its de-embedding and parameter extraction procedure. The S-parameters were measured up to 1 GHz using network analyzer, HP8753D, and N-type connector together with the de-embedding of N-type connector. The proposed de-embedding procedure is performed to extract electrical parameters of blood glucose, which gives the permittivity of blood glucose. We also analyzed the error of extracted parameters, which are caused by instrument error and geometrical error. Using these error analyses, we reduced the error factors of extracted parameters. We extracted electrical parameters of glucose samples through these all extraction procedure and confirmed the possibility of glucose diagnosis system based on microwave system.

• 한국정보통신학회논문지
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• 제10권12호
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• pp.2296-2302
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• 2006

본 논문에서는 빛의 세기에 크게 영향을 받지 않고 정밀한 거리 계측과 측정 속도를 대폭 개선할 수 있는 기술로서 5m 단위의 거리 계측에는 비행 펄스 시간 방법을 사용하고, 1mm 단위의 계측에는 헤테로다인 방법을 적용하여, 장거리계측이 가능하게 함과 동시에 측정오차 1mm 이내, 측정 거리 1km 이내의 고정밀의 거리 계측이 가능한 방법을 개발하고 그 유용성을 검증하였다.

• 한국기계가공학회지
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• 제16권3호
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• pp.69-75
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• 2017

There are two types of expensive measuring instruments currently on the market shape measurement and roundness measurement instruments. As they are very expensive, from tens of millions to more than 200 million won, buying them is economically burdensome for small companies or individuals. Therefore, in order to integrate the shape and roundness measurements into a single transfer device, this study aimed to reduce the trial and error by 3D modeling and simulation, and we confirmed the feasibility of operation. Based on these outcomes, a prototype hybrid measuring instrument was fabricated. As a result of performance evaluation and comparative evaluation, we verified the feasibility of implementation and application of the hybrid measuring instrument.