• 융합신호처리학회논문지
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• 제21권1호
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• pp.1-6
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• 2020

염전의 자동화 시스템 구성을 위해서는 증발지의 염도 및 수위 측정이 필요하다. 이를 위해 본 논문에서는 2개의 고정된 부력체의 부력을 측정하여 함수의 염도 및 수위를 동시에 측정할 수 있는 방법을 제안하였다. 제안된 측정방식은 측정 장치가 함수에 잠기게 될 때 주부력체와 비교부력체의 부력을 측정하고, 두 부력의 합과 차를 통해 염도와 수위를 동시에 측정하는 것이다. 부력의 측정에 기계적인 움직임이 없어서 뻘이 포함된 염전의 환경에서 측정 오류와 유지보수가 필요성을 줄일 수 있다. 제안된 방법을 적용하여 염전의 증발지에서 원격으로 염도 및 수위를 동시에 측정할 수는 있는 시스템을 개발하였다. 여러 수준의 염도를 갖는 기준함수를 사용한 측정 실험을 통하여 염도 오차 0%, 수위 오차 2mm의 결과를 얻고, 제안된 염도 및 수위 측정 장치의 유효성을 확인하였다. 개발된 염도 및 수위 측정 장치를 활용하여 자동화 시스템을 구성할 경우 노동력 절감 및 작업 환경 개선과 생산성 증진이 기대된다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2002년도 학술대회논문집
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• pp.383-388
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• 2002

The appropriateness or in appropriateness for the standard value and presentation problem after measuring the electromagnetic field occurring in an electrical railroad.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 C
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• pp.1668-1670
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• 2002

Since more than two decades, the conventional PD detecting systems have been employed in order to detect the partial discharges occurring inside the HV power apparatus for their diagnosis by use of different type of detection such as acoustic and UHF detection method. Regardless of their wide on-site application, a certain number of technical inconveniences have been disclosed as follows : multistage amplification. large volume, susceptible to external noise and high price. In this respect, the optical measurement techniques are widely proposed in these days in this concerned field ascribed to the following advantages : immune to external EMI noise and broad band response of the Pockels cell covering from DC to GHz. However, the reliability of several proposed techniques enabling to measure the electric field inside the large high power apparatus has not yet been well approved In this work, an optical measuring system, based on the Pockels effect, has been developed for measuring the field variation due to the corona discharges occurring in air and in oil. This system consists of He-Ne laser, single mode optical fiber, multi mode optical fiber, polarizing film, Y-cut LiNbO3 cell, photo detector, digital oscilloscope and personal computer with GPIB. For this purpose, optical probe has been specially designed and realized and put into the needle-plane electrode. Afterward, same measurement is carried out in oil. We demonstrate the characteristic of the optical measuring system and the measurement results.

• Journal of Biosystems Engineering
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• 제28권3호
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• pp.245-252
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• 2003

This study was investigated the possibility of measuring chlorophyll in paddy crops using two kinds of chlorophyll meters(SPAD-502, Field Scout). The results of correlation analysis showed the 0.7758(r$^2$) relationship between the chlorophyll contents of paddy leaves measured by SPAD and spectrophotometer. It indicates that chlorophyll content in paddy crops could be measured using the SPAD. Considering the data of the SPAD and Field Scout there was significant difference between their chlorophyll contents measured by the SPAD and Field Scout. Likewise, such results were consistent with the corrected data using light intensity. According to the results, it can be concluded that it is difficult to describe the rice chlorophyll measured by the Field Scout more accurately than the SPAD when using one standard spectrum and another spectrum for reflectance measuring. The chlorophyll variance measured at a research institute and a farmer's field revealed that the output of SPAD was more reliable than that of the Field Scout.

• Journal of Mechanical Science and Technology
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• 제16권2호
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• pp.175-181
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• 2002

A new polariscope system involving two rotating optical elements and a digital camera for whole field fringe analysis allows automated data to be acquired quickly and efficiently. The developed phase measuring technique that uses eight images through a circular polariscope is presented for the digital measurement of isochromatics and isoclinics, respectively, from photoelastic fringes in a circular disk under diametric compression. Isochromatics can directly be obtained using wrapped isoclinic phases calculated by the arc tangent operator which is the four-quadrant operator from -$\pi$ to $\pi$. It is not required to unwrap isoclinic phases for the calculations of isochromatics. Unwrapped isoclinics are directly determined from isochromatic parameters. Distributions of digitally determined isoclinics are in close agreement to manual measurements. The errors which would appear in unwrapping process of isoclinics can be avoided in the determination of isochromatics.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 I
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• pp.252-256
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• 2001

Scattering of surface materials has been known as one of the most important aspects in evaluating the acoustics of concert halls are designed. One of the methods that can reduce the errors in estimating the reverberation time and other acoustic parameters through computer modeling is to calculate scattering coefficient of surface materials. However. so far, no objective and reliable methods measuring scattering coefficient has been suggested. In this situation, ISO has suggested the method of measuring the random-incidence scattering coefficient on surfaces in diffuse field, whereas AES has introduced a method on directional-incidence in free field. In this study, the scattering coefficients of five kinds of hemispheres (1.5, 2.0. 2.5. 3.0. 3.5cm) were measured by using the ISO method in 1：10 reverberation chamber. It was found that 3.0cm hemisphere has the highest scattering coefficient satisfying 95％ reliability.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권2호
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• pp.109-115
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• 2004

This paper deals with the behaviors of magnetic flux density near down-conductors by lightning currents. The background on the principle of magnetic flux density measurements using the RL self-integrating magnetic field sensor was described. The magnetic flux density measuring device consisting of RL self-integrating magnetic field sensor and differential amplifier was designed and fabricated. The frequency bandwidth of the magnetic flux density measuring system ranges from 200 Hz to 300 KHz and the response sensitivity was 0.126 $\mu$T/㎷ The distributions of the magnetic flux density near down-conductors due to impulse currents with various rise times were analyzed as a parameter of the bonding conditions and materials of conductor and wiring conduits. The magnetic flux density due to impulse currents was inversely proportional to the distance between the down-conductor and measuring point. The amplitude of the magnetic flux density for PVC Pipe with down-conductor was 72 $\mu$T/㎷ at the distance of 1m and was higher than for steel conduits and coaxial cable. Finally the magnetic flux density is increased with increasing the di/dt it and oscillation frequency of lightning currents in this experimental ranges.

• Current Optics and Photonics
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• 제2권6호
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• pp.568-575
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• 2018

Various techniques to measure the three-dimensional (3D) surface profile of a 3D micro- or nanostructure have been proposed. However, it is difficult to apply such techniques directly to industrial uses because most of them are relatively slow, unreliable, and expensive. The HiLo optical imaging technique, which was recently introduced in the field of fluorescence imaging, is a promising wide-field imaging technique capable of high-speed imaging with a simple optical configuration. It has not been used in measuring a 3D surface profile although confocal microscopy originally developed for fluorescence imaging has been adapted to the field of 3D optical measurement for a long time. In this paper, to the best of our knowledge, the HiLo optical imaging technique for measuring a 3D surface profile is proposed for the first time. Its optical configuration and algorithm for a precisely detecting surface position are designed, optimized, and implemented. Optical performance for several 3D microscale structures is evaluated, and it is confirmed that the capability of measuring a 3D surface profile with HiLo optical imaging technique is comparable to that with confocal microscopy.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.540-543
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• 2003

This paper presents design and manufacture of RF type non-contact radiological dosage measuring device. It also concerns on the broad out-line and the ways of improvement about RF type non-contact radiation measuring device. Measuring radiological dosage with non-contact RF, the stability and efficiency of the measure have been improved by reforming constant current circuit. Furthermore, applying communication protocol in process makes it possible to achieve faster and more accurate communication than old circuit. On the base of those, RF type non-contact radiological dosage measuring device which consists of radiological dosage measuring module and Reader module has been designed and manufactured. While testing communication against embodied device, the possibility of the field application could be confirmed.

• 한국정밀공학회지
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• 제18권10호
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• pp.84-92
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• 2001

Commercial eddy current dynamometers control the torque of rotating body, power supply machine, with the field coil current being operated as a braking force. In this paper, we studied the relation between field coil current and torque load of eddy current dynamometer. By the torque measuring analysis of eddy current dynamometer it is linear relation between the brake force measured from a torque meter which is installed at the case of dynamometer and the multiplied shaft rpm by the squares of field coil current (N$\times$I$^2$). To prove the relation, it was experimented and showed that the torque operated by the rotating body can be measured with the shaft rpm and the field coil current of the eddy current dynamometer. This result shows a possibility that eddy current dynamometer can measure the torque of rotating body without a torque measuring device. such as load cell.