• Journal of Industrial Technology
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• v.17
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• pp.95-101
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• 1997

A smart pressure measurement system is described, which provides a precise A/D conversion and is highly suitable for communication with microprocessors. In order to avoid unstable problems of remote pressure sensing we have developed a new interface board which performs the A/D conversion and smart signal processing of the measured pressure data. Serial communication software which is based on ASCII code commands is also developed to process initial setup and calibration functions as well as multi-drop communication with PC. The test and evaluation of the proposed system has been shown as having the better performance compared to the other types of existing pressure measuring systems and will give good applications to the industrial use where a highly precision remote sensing is needed.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.462-467
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• 1999

In this paper, very high performance millimeter-wave radiometer of 92 GHz is presented. Radiometer system design, brightness temperature measurement and calibration methods are described. The architecture of radiometer including data acquisition, storage and digital signal processing using a notebook computer are explained and some experimental data in the laboratory are introduced. The system noise figure and total gain of implemented radiometer are 12 dB and 56 dB, respectively. The system stability is evaluated from the experiment. The difference of the detector output voltage for two targets, whose brightness temperature are 80 K and 300K, is 4 mV. The mechanical scanning method is considered to get a brightness temperature Image of the earth surface scene.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.684_685
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• 2009

A digital sampling algorithm that uses a two high resolution integrating Voltmeters which are synchronized by Phase Lock Loop (PLL) time clock for accurately measuring the parameters, active and reactive power, for sinusoidal power measurements is presented. The PLL technique provides high precision measurements, root mean square (rms), phase and complex voltage ratio, of the AC signal. The system has been designed to be used at the Korean Research Institute of Standards and Science (KRISS) as a reference power standard for electrical power calibrations. The test results have shown that the accuracy of the measurements is better than $10 {\mu}W/VA$ and the level of uncertainty is valid for the power factor range zero to 1 for both lead and lag conditions. The system is fully automated and allows power measurements and calibration of high precision wattmeters and power calibrators at the main power frequencies 50 and 60 Hz.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.3
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• pp.645-654
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• 2009

In this study, we present an efficient ambulatory speech audiometric system to detect one's hearing problems at an earlier stage as possible without his or her visit to the audiometric testing facility such in a hospital or a clinic. To estimate a person's hearing threshold level in terms of speech sound response in his or her local environment, a digital assistant(PDA) device is used to generate the speech sound with implementing audiometric Graphic User Interface(GUI) system. Furthermore, a supra-aural earphone is used to measure a subject's hearing threshold level in terms of speech sound by the compensating the transducer's gain by adopting speech sound calibration system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.11a
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• pp.131-132
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• 2011

Image-based survey can be performed for a floating structure using the hydraulic model tests and empirical methods. I extracted the frame images from a digital camcoder movies and found the corner points for image matching. In the future, we will try the movie acquisition in the improved lab environment for a precise result.

• IEIE Transactions on Smart Processing and Computing
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• v.3 no.4
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• pp.161-166
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• 2014

An accurate gain-of-two amplifier, which successfully reduces the capacitor mismatch error is proposed. This amplifier has similar circuit complexity and linearity improvement to the capacitor error-averaging technique, but operates with two clock phases just like the conventional pipeline stage. This makes it suitable for high-speed, high-resolution analog-to-digital converters (ADCs). Two ADC architectures employing the proposed accurate gain-of-two amplifier are also presented. The simulation results show that the proposed ADCs can achieve 15-bit linearity with 8-bit capacitor matching.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.119.1-119.1
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• 2014

We present the scanned digital images and their preliminary analysis results of objective-prism plates taken with the Michigan Curtis Schmidt telescope at Cerro Tololo Inter-American Observatory. In order to separate an individual spectrum of a star, it should be required to identify each field star in the plate. Using the PPM(Position and Proper Motion) catalog, we are verifying which star corresponds to the spectrum in a plate. In addition to this, we plan to devise the method for wavelength calibration in each spectrum. Finally we will make them for public use, not only for professional astronomers but also for high school and college students for encouraging them to be interested in the astronomy, especially astronomical spectroscopy and stellar astronomy.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.1335-1338
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• 2002

This paper presents the analysis of the required limit on a multibeam active phased array antenna (APAA) aperture using the statistical simulation for a High Altitude Platform Station (HAPS). The simulation takes into account the random errors caused by the non-identity of the array elements and the inaccuracy of the antenna calibration. The results of our statistical simulation show that the strict requirements on the sidelobe envelope for HAPSs can be met when the amplitude and phase distribution errors are minor, a condition which may be achieved by using digital beam forming.

• Journal of the Ergonomics Society of Korea
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• v.14 no.2
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• pp.75-85
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• 1995

The purpose of this study is to develop a force-platform system suitable for real situations in industry. The developed system is a 3-axis measurement type. It consists of force-transmission, force measuring circuit, and the software that analyzes the measured force. The force-transmission transmits forces to 3 axes, which has a physical structure to minimize the interference among those axes. Force measuring circuit consists of DSP (digital signal processor) for flexible disposal of change of measurement algorithm, elimination of noise and maintenance of precision. The functions of the software are the calibration which revises the measurement error occuring during data acquisition, and various analyses of forces. The result of the experiment shows that the developed system has about 1% measurement error, is stable for repeated experiments, and is not effected by temperature change.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.06a
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• pp.34-39
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• 2006

An automated surface-strain measurement system, named ASIAS, was developed by using the image processing and stereo vision techniques in the previous studies by the corresponding author and his coworkers. This system has been upgraded mainly to improve the accuracy through image enhancement, sub-pixel measurement, surface smoothing, etc., since the first version was released. The present study has still more improved the convenience of users as well as the accuracy of measurement by processing high resolution images 8 mega pixels or more which can be easily obtained from a portable digital steal camera. It is proved that high resolution image processing greatly decreases the measurement error and gives strain data without considerable deterioration of accuracy even when the deformed grids to be measured and the master grids for camera calibration are captured together in the same image, making the whole process of strain measurement much simpler.