• Journal of the Korean Physical Society
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• v.73 no.12
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• pp.1821-1826
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• 2018

Uniformity is a key feature of state-of-the-art infrared focal planed array (IRFPA) and infrared imaging system. Unlike traditional infrared telescope facility, a ground-based infrared radiant characteristics measurement system with an IRFPA not only provides a series of high signal-to-noise ratio (SNR) infrared image but also ensures the validity of radiant measurement data. Normally, a long integration time tends to produce a high SNR infrared image for infrared radiant characteristics radiometry system. In view of the variability of and uncertainty in the measured target's energy, the operation of switching the integration time and attenuators usually guarantees the guality of the infrared radiation measurement data obtainted during the infrared radiant characteristics radiometry process. Non-uniformity correction (NUC) coefficients in a given integration time are often applied to a specified integration time. If the integration time is switched, the SNR for the infrared imaging will degenerate rapidly. Considering the effect of the SNR for the infrared image and the infrared radiant characteristics radiometry above, we propose a-wide-dynamic-range NUC algorithm. In addition, this essasy derives and establishes the mathematical modal of the algorithm in detail. Then, we conduct verification experiments by using a ground-based MWIR(Mid-wave Infared) radiant characteristics radiometry system with an Ø400 mm aperture. The experimental results obtained using the proposed algorithm and the traditional algorithm for different integration time are compared. The statistical data shows that the average non-uniformity for the proposed algorithm decreased from 0.77% to 0.21% at 2.5 ms and from 1.33% to 0.26% at 5.5 ms. The testing results demonstrate that the usage of suggested algorithm can improve infrared imaging quality and radiation measurement accuracy.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.8
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• pp.1799-1804
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• 2005

We have developed and estimated the measurement system of $CO_2$ and Nd:YAG laser power of wide range. The absorber is made of gold-plated copper cavity. The calibration heater is using a manganin(CuMn12Ni) coil, and output power is measured by using or resistance bridge with composed manganin and copper coil. Developed system can measure 5${\~}$1000W laser output power range. Calibration factors are 489.13J/mV at 100W and 497.04(J/mV) at 500W. correction factors are 0.99 at 100W and 1.006 at 500W.

• International conference on construction engineering and project management
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• 2017.10a
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• pp.260-262
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• 2017

During the construction of the project, all surveying and mapping work is collectively referred to as engineering survey. Therefore, the measurement work contains a wide range of content, in the engineering survey, design and construction management stage are involved. To the actual work, the project measurement runs through the project building in a number of stages, and provide basic services. This paper mainly through the analysis of engineering measurement at all stages of the role played by the measurement work in the project management work to do the following description.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.100-103
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• 2003

A Ku-band Push-push VCO for low cost applications is proposed. The proposed push-push oscillator achieves a wide tuning range in Ku-band by the collector bias tuning instead of extra varactor diodes. The measurement shows a wide tuning range of 900MHz, fundamental suppression of -30dBc and good phase noise of -115dBc@1MHz offset.

• Korean Journal of Materials Research
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• v.27 no.3
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• pp.127-131
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• 2017

Isosteric heat of hydrogen adsorption is one of the most important parameters required to describe solid-state hydrogen storage systems. Typically, it is calculated from adsorption isotherms measured at 77K (liquid N2) and 87K (liquid Ar). This simple calculation, however, results in a high degree of uncertainty due to the small temperature range. Therefore, the original Sievert type setup is upgraded using a heating and cooling device to regulate the wide sample temperature. This upgraded setup allows a wide temperature range for isotherms (77K ~ 117K) providing a minimized uncertainty (error) of measurement for adsorption enthalpy calculation and yielding reliable results. To this end, we measure the isosteric heats of hydrogen adsorption of two prototypical samples: activated carbon and metal-organic frameworks (e.g. MIL-53), and compared the small temperature range (77~87K) to the wide one (77K ~ 117K).

• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.158-161
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• 1995

A new laser diode range-finding speedometer is proposed, which is modulated by a pair of positive and negative triangular pulse current superimposed on a dc current. Since a target velocity is directly obtained form a pure Doppler beat frequency measured during the non-modulation period, the new sensor is free from the difficulties due to the critical velocity encountered in the previous sensor. Furthermore, the different amplitude of the two triangular pluses are so adjusted that the measurable range using only one laser head is greatly expanded to 10cm through 150cm, which is about two times that of the previous sensor. The measurement accuracy for velocity of .+-.6mm/s through .+-.20mm/s and for range is about 1%, and 2%, respectively. Because the new sensor can be operated automatically using a microcomputer, it will be useful for application of a 3-D range image measurement of a slowly moving object.

• Nuclear Engineering and Technology
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• v.35 no.3
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• pp.234-242
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• 2003

The full energy peak efficiency of a hyper pure germanium (HPGe) detector was calibrated in a wide energy range from 0.06 to 11 MeV. Both the experimental technique and the Monte Carlo method were used for the efficiency calibration. The measurement was performed using the standard radioisotopes in the low energy region of $60{\sim}1408$ keV, which was further extended up to 11 MeV by using the $^{14}N(n,r)\;and\;^{35}Cl(n,r)$ reactions. The GEANT Monte Carlo code was used for efficiency calculation. The calculated efficiency had the same dependency on the r-ray energy with the measurement, and the discrepancy between the calculation and the measurement was minimized by fine-tuning of the detector geometry. From the calculated result, the efficiency curve of the HPGe detector was reliably determined particularly in the high energy region above several MeV, where the number of measured efficiency points is relatively small despite the wide energy region. The calculated efficiency agreed with the measurement within about $7\%$. In addition to the efficiency calculation, the origin of the local minimum near 600 keV on the efficiency curve was analyzed as a general characteristics of a HPGe detector.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.3
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• pp.414-424
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• 2017

This paper introduces an experimental device which can measure accurate aerodynamic forces without support interference in wide experimental region for wind tunnel test of micro aerial vehicles (MAVs). A stereo pattern recognition (SPR) method was introduced to a magnetic suspension and balance system (MSBS), which can eliminate support interference by levitating the experimental model, to establish wider experimental region; thereby MSBS-SPR integrated system was developed. The SPR method is non-contact, highly accurate three-dimensional position measurement method providing wide measurement range. To evaluate the system performance, a series of performance evaluations including SPR system measurement accuracy and 6 degrees of freedom (DOFs) position/attitude control of the MAV model were conducted. This newly developed system could control the MAV model rapidly and accurately within almost 60mm for translational DOFs and 40deg for rotational DOFs inside of $300{\times}300mm$ test section. In addition, a static wind tunnel test was conducted to verify the aerodynamic force measurement capability. It turned out that this system could accurately measure the aerodynamic forces in low Reynolds number, even for the weak forces which were hard to measure using typical balance system, without making any mechanical contact with the MAV model.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1089-1090
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• 2011

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.10
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• pp.568-572
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• 2002

High precision voltages, currents, and electrical power measurements in wide range of frequency can be achieved by using the thermo-elements(thermal converters). This paper describes a development wattmeter, based on a thermal principle. The instrument has been performed measurement in the range of currents from 0 to 50 A, voltages up to 480 V, power factor 0.5 (lag, lead), 1 and frequencies from 60 Hz to 3 KHz. It is intended to be used by electric utilities, standard laboratories, testing laboratories, and applications where high measurement accuracy are attractive consideration.