• 센서학회지
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• 제11권2호
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• pp.111-117
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• 2002

본 논문에서는 반도체 소자의 특성 분석을 위한 시스템에서 측정 회로에 의해 발생하는 오차를 감소시켜 측정 정밀도를 개선시키기 위한 보정 과정을 제안하였다. 또한 pA 수준의 저전류 측정을 위해서 누설 전류, 오프셋 전류와 같은 오차 전류를 감소시키기 위한 보상 기법을 제안하였다. 보정계수는 마이크로프로세서에 의해 보정 과정에서 수집된 데이터로부터 구해진다. 수집된 데이터를 최소 자승 오차법을 사용하여 다항식으로 근사하는 방법으로 보정 계수를 계산하고 저장한다. 측정 시에는 마이크로프로세서가 저장된 보정 계수를 사용하여 측정 오차를 교정하여 준다. 실험 결과에서 nA 이상의 전류를 측정할 경우 측정 오차가 0.02% 이하를 가지며 pA 수준의 저전류도 0.2% 정도의 오차로 측정 가능함을 확인하였다.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2003년도 학술발표논문집
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• pp.491-494
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• 2003

An Automatic Water Level Measurement System has been developed in this study. It has the characteristics that it use lower power and solar power and it has the ability of sending data and remote-controlled by wireless MODEM this system was set up in the experimental site and was tested. Also, the management system for the water level data has been developed and will be used by instruments administrating reservoirs.

• 센서학회지
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• 제27권5호
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• pp.300-305
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• 2018

The uncooled microbolometer thermal sensor for low cost and mass volume was designed to target the new infrared market that includes smart device, automotive, energy management, and so on. The microbolometer sensor features 80x60 pixels low-resolution format and enables the use of wafer-level vacuum packaging (WLVP) technology. Read-out IC (ROIC) implements infrared signal detection and offset correction for fixed pattern noise (FPN) using an internal digital to analog convertor (DAC) value control function. A reliable WLVP thermal sensor was obtained with the design of lid wafer, the formation of Au80%wtSn20% eutectic solder, outgassing control and wafer to wafer bonding condition. The measurement of thermal conductance enables us to inspect the internal atmosphere condition of WLVP microbolometer sensor. The difference between the measurement value and design one is $3.6{\times}10-9$ [W/K] which indicates that thermal loss is mainly on account of floating legs. The mean time to failure (MTTF) of a WLVP thermal sensor is estimated to be about 10.2 years with a confidence level of 95 %. Reliability tests such as high temperature/low temperature, bump, vibration, etc. were also conducted. Devices were found to work properly after accelerated stress tests. A thermal camera with visible camera was developed. The thermal camera is available for non-contact temperature measurement providing an image that merged the thermal image and the visible image.

• 한국정보통신학회논문지
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• 제2권2호
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• pp.241-248
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• 1998

실내 소음의 정확한 측정은 환경소음 관리상에 요구되어 지는 것이나 측정계 자체의 잡음으로 인하여 소음원이 가지는 원래의 잡음이 항상 영향을 받게되는 문제가 있다. 본 연구에서는 새로운 소음레벨 측정기술로서 크로스 스펙트럼법을 사용하여 측정된 신호로부터 측정계가 가지는 잡음을 효과적으로 제거하는 방법을 제안하였다. 두 개의 측정용 마이크로폰으로부터 받아들인 신호는 각각의 전치 증폭기를 통하여 A/D 변환기에 의해 디지털 신호화하여 크로스 스펙트럼을 이 디지털화 된 신호로부터 계산하고 측정계가 가지는 잡음과 소음 원의 잡음은 서로 무상관이므로 우리가 원하는 정확한 소음레벨을 측정할 수 있는 것이다. 제안된 기술의 성과는 염가의 상용 마이크로폰으로도 사용할 수 있었기 때문에 실험적으로 그 유효성과 경제성이 입증되었다.

• 한국인터넷방송통신학회논문지
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• 제10권5호
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• pp.277-286
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• 2010

본 논문에서는 다가올 초고속 무선 서비스의 핵심 서비스 중의 하나로 부각되고 있는 UWB 무선통신 시스템에서 광대역 저출력 주파수 특성의 방사출력 측정방법에 대하여 연구하였다. UWB 시스템의 측정환경에서는 RMS 전계강도 측정, UWB PSD 측정, 검출 가능한 UWB 신호레벨, UWB 천이신호 수집 등에 대해서 언급하였다. 또한, CIDPR16-1에서 언급한 축력 측정법에 대해 분석하였으며 저 준위 e.i.r.p 복사 측정법에 대해 세부적으로 분석하였다. 마지막으로는 신호분석기를 이용하여 측정시의 고려사항에 대해 서술함으로써 UWB 시스템 상용화에 필요한 방사출력 측정에 필요한 내용을 마무리하였다.

• 한국군사과학기술학회지
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• 제6권2호
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• pp.55-64
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• 2003

Underwater acoustic noise measurement is an essential element for vulnerability assessment of modern naval platforms. But during the last few decades environmental conditions have drastically changed due to the gradually increasing sea ambient noise level and decreasing submarine radiated noise level. A real-time underwater acoustic measurement system with vertical line array is designed for the quiet submarine radiated noise assessment in challenging environment. This system has a constant directivity index in measurement frequency range and accurate tracking capability for the transmission loss compensation and navigation aids inside the submarine. This system has been validated at sea and used several times for the submarine noise measurement.

• 한국전기전자재료학회논문지
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• 제18권10호
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• pp.960-964
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• 2005

In this paper, we dealt with a partial discharge(PD) measurement method that has been accepted as an effective and non-destructive technique to estimate insulation performance of low-voltage electric and electronic devices. The PD measurement system Is composed of a coupling network, a low noise amplifier, and associated electronics. h shielded box Is adopted to make a better measurement environment against around noise. A low cut-off frequency of the coupling network estimated by a sinusoidal wave input was 125 kHz (-3 dB). Calibration tests on laboratory set-up have shown that the PD measurement system has a stable sensitivity of 10 mV/pC. In an application test oil a low-voltage three phase Induction motor (5 HP), we could detect 0.53 pC level of partial discharge at the applied voltage of AC 650 $V_{peak}$.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 추계종합학술대회
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• pp.208-211
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• 2005

This paper presents an ultra-low partial discharge(PD) measurement system that has been accepted as a non-destructive method to estimate electrical insulation of low-voltage electric devices. The PD measurement system is composed of a coupling network, a low noise amplifier, and associated electronics. A shielding box is used to make a better condition against electromagnetic interference. A low cut-off frequency of the coupling network was 1MHz(-3 dB). Calibration tests on laboratory set-up have shown that the PD measurement system has a stable sensitivity of 11.4mV/pC. In an application experiment on a low-voltage induction motor(5HP), we could detect 0.77pC level of partial discharge pulse at the applied voltage of AC 664 V$_{peak}$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.591-593
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• 2006

The differential pressure method has been used in the level measurement of steam generator in nuclear power plant. Two sensing lines from a steam generator to a pressure transmitter are needed to measure the high pressure and low pressure. The fluid conditions in the sensing line require the uniform phase with no bubbles and the slope of sensing line should be installed with forward slope. The expansion of the bubble volume according to the upper pressure and the reverse slope of sensing lines explain how the level errors took place.

• 한국소음진동공학회논문집
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• 제24권1호
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• pp.35-44
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• 2014

Sound pressure levels in the receiving room while testing airborne sound insulation performance are varied by the measuring points. This may increase the measurement error, then decrease the measurement reliability. With this reason the research has carried out on the method to reduce deviations of sound pressure level in the ISO type rectangular laboratory focusing on the measurement of airborne sound insulation performance. Tests were made to see the effect of sound absorption in the receiving room, loudspeaker locations, microphones locations and flanking transmission path. Consequently, it was resulted that sound absorption in the receiving room and the loudspeaker location have influence on the sound level deviations especially in the low frequency. The microphone location was very important to get measurement reliability. The effective measuring point, which the sound level difference with average sound pressure level is within 2 dB, could yield most reliable average sound pressure level. Therefore it is necessary to find the effective measuring points in the receiving room. Flanking transmission path should be sealed using sound absorber or magnet etc. to prevent from lowering the sound insulation performance.