• Journal of Electrical Engineering and Technology
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• 제9권4호
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• pp.1332-1342
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• 2014

This paper proposes a novel test circuit for SiC transistors. On-state resistance under practical application conditions is an important characteristic for the device reliability and conduction efficiency of SiC transistors. In order to measure the on-state resistance in practical applications, high voltage is needed, and high current is also necessary to ignite performance for the devices. A soft-switching circuit based on synchronous buck topology is developed in this paper. To provide high-voltage and high-current stresses for the devices without additional spikes and oscillations, a resonant circuit has been introduced. Using the novel circuit technology, soft-switching can be successfully realized for all the switches. Furthermore, in order to achieve accurate measurement of on-state resistance under switching operations, an active clamp circuit is employed. Operation principle and design analysis of the circuit are discussed. The dynamic measurement method is illustrated in detail. Simulation and experiments were carried out to verify the feasibility of the circuit. A special test circuit has been developed and built. Experimental results confirm that the proposed circuit gives a good insight of the devices performance in real applications.

• 한국의류산업학회지
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• 제18권4호
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• pp.468-476
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• 2016

Recent advancements in optics technology enable us to realize fast scans of hands using two-dimensional (2D) image scanners. In this paper, we propose an automatic hand measurement system using 2D image scanners for customized glove production. To develop the automatic hand measurement system, firstly hand scanning devices has been constructed. The devices are designed to block external lights and have user interface to guide hand posture during scanning. After hands are scanned, hand contour is extracted using binary image processing, noise elimination and outline tracing. And then, 19 hand landmarks are automatically detected using an automatic hand landmark detection algorithm based on geometric feature analysis. Then, automatic hand measurement program is executed based on the automatically extracted landmarks and measurement algorithms. The automatic hand measurement algorithms have been developed for 18 hand measurements required for custom-made glove pattern making. The program has been coded using the C++ programming language. We have implemented experiments to demonstrate the validity of the system using 11 subjects (8 males, 3 females) by comparing automatic 2D scan measurements with manual measurements. The result shows that the automatic 2D scan measurements are acceptable in the customized glove making industry. Our evaluation results confirm its effectiveness and robustness.

• 대한전자공학회논문지SD
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• 제41권4호
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• pp.9-14
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• 2004

매몰 산화층 밑의 실리콘 기판에 자기정렬 방법으로 ground plane 전극을 만든 SOI MOSFET의 단채널 현상과 Punchthrough 특성을 측정·분석하였다. 채널 길이가 $0.2{\mu}m$ 이하의 소자에서는 GP-SOI 소자가 FD-SOI 소자보다 채널 길이에 따른 문턱전압 저하 및 subthreshold swing이 작고 DIBL 현상이 크게 개선됨을 알 수 있었다. 기판전압에 따른 문턱전압 특성으로부터 GP-SOI 소자의 body factor가 FD-SOI 소자보다 큰 것을 알 수 있었다. 그리고 punchthrough 전압 특성으로부터 GP-SOI 소자의 punchthrough 전압이 FD-SOI 소자보다 큰 것을 알 수 있었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.447-447
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• 2011

We studied to detect the mass variation using micro mechanical resonator. For measuring the resonance frequency of the micro mechanical system, optical method using laser interference is selected. A simple resonator is prepared by attaching an AFM cantilever on the piezo stack. The piezo stack makes a the cantilever vibrated with its resonance frequency. To change the mass of the resonator, gold was evaporated on the cantilever. We measured how much resonance frequency was changed according to the amount of gold attached on cantilever. This resonator is able to perform the role of a mass sensor and has a resolution of the order of micrograms. The fabrication of the resonator and measurement setup for detecting the mechanical resonance will be introduced in this presentation.

• 산업경영시스템학회지
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• 제20권41호
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• pp.221-229
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• 1997

This study concerns with the comparing and evaluation for Signal - Noise Ratio of the quantitative signal factors in the measurement devices for developing efficiency for product system. On the basis of this conditions and purpose, this study presents a general procedure for deriving the Signal - Noise Ratio, confidence intervals and significiant testing for the measurement devices.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.70-72
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• 2007

In this study, electromagnetic fields emitted from the various environment in the hospital were measured. Measurement spot was patients' head. To monitor how much magnetic fields are emitting from operation room, monitoring device was attached to 19 anesthesiologist and monitoring lasted 8 hours. We also took a measurement from various medical devices. Devices include ESWL, PET, MRI, CT, Gamma knife, X-ray, Angiogram, Echocardiogram, Upper GI and Linear Accelerator. Electromagnetic fields were measured from 10 spots from each of 5 patient waiting room. As a results, there were no places showing risk of high exposure. All the measurement values were below the reference levels for general public exposure to time varying electric and magnetic fields which is issued by ICNIRP.

• 대한조선학회 특별논문집
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• 대한조선학회 2015년도 특별논문집
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• pp.28-33
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• 2015

Speed log measurement has always been of utmost importance to the mariners. To date the most accurate maritime speed measurement comes from Doppler measurement, where speed may be measured relative to either water(speed through water) or seabed(speed over ground). Recently, a clarification has been issued by the International Maritime Organization (IMO) regarding the speed measuring devices, which could ultimately impact the final arrangement of these devices for ships being constructed after July 1, 2014. This paper will discuss the clarification in depth and necessary action which shall be taken by the owners and operators of the ships impacted.

• 반도체디스플레이기술학회지
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• 제17권1호
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• pp.50-53
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• 2018

Cyclic measurement system using relay circuit for organic light emitting diode (OLED) was demonstrated. The OLED characterization such as current-voltage, impedance, and capacitance-voltage is performed in sequence, repetitively and automatically under full control of the personnel computer (PC) without changing the connection of cables. Owing to in situ degradation by cyclic measurement, the time dependence of the data can give good information on the reliability factor of the OLED devices. Therefore, both performance and reliability of the OLEDs can be evaluated, with no manual operation during the entire process.

• Journal of Acupuncture Research
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• 제29권5호
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• pp.127-137
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• 2012

Objectives : The purpose of this study is to review on current status of use and measurement condition of heart rate variability(HRV) by reviewing clinical studies published in journal of Korean medicine registered Korea citraion index(KCI). Methods : One hundred twenty articles were found by searching the representative Korean databases. At first analysis was performed by current status of use(journal, academic field of corresponing author, purpose of study, disease of subject, HRV measurement devices, intervention methods and tests compared to HRV). At second analysis was performed by measurement condition(uncontrolled study, relaxation before measurement, measurement position, measurement place, measurement time period and restriction of smoking, alcohol, caffeine, meal). Results : The analysis showed that department of acupuncture & moxibustion, department of oriental neuropsychiatry are major part in journal & academic field. The purpose of study were classified under studies to verify therapeutic effect on normal subject(39%), to verify therapeutic effect on the patients(8%), to investigate characteristics of the patients(34%) and to be compared with other test(19%). Disease of subject & measurement devices in article were so various. Major intervention methods were acupuncture(61.4%), mind-body intervention(19.2%). Studies that measurement condition were not controlled were relax time(24%), measurement position(19%), measurement place(26%), measurement time period(91%) and restriction of smoking, alcohol, caffeine, meal(49%). Conclusions : This study showed that current status of use of HRV is widespread in Korean medicine but more controlled measurement conditon are needed to get more reliable result from clinical studies and to improve diagnosis and treatment of Korean medicine.

• Current Optics and Photonics
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• 제6권4호
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• pp.392-399
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• 2022

Light-measuring devices (LMDs) are frequently used to measure luminance and color coordinates of displays. However, it is very difficult to use a conventional LMD for measuring the optical properties of virtual-reality (VR) devices with a wide field of view (FOV), because of their confined spaces where the entrance pupil of a LMD is located. In this paper, a new LMD that can measure the optical properties of wide-FOV VR devices, without physical conflict with the goggles of the VR device, is proposed. The LMD is designed to fully satisfy the requirements of IEC 63145-20-10, and a pivot-point correction method for the LMD is applied to improve its accuracy. To show the feasibility of the developed LMD and the correction method, seven VR devices with wide FOV are measured with it. From the results, all of them are successfully measured without any physical conflict, and a comparison to their nominal values shows that the FOVs have been properly measured.