• Title, Summary, Keyword: channel measurement

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Design and Implementation of a DSP-Based Multi-Channel Power Measurement System

  • Jeon Jeong-Chay;Oh Hun
    • KIEE International Transactions on Power Engineering
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    • v.5A no.3
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    • pp.214-220
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    • 2005
  • In order to improve energy efficiency and solve power disturbances, power components measurement for both the supply and demand side of a power system must be implemented before appropriate action on the power problems can be taken. This paper presents a DSP (Digital Signal Processor)-based multi-channel (voltage 8-channel and current 10-channel) power measurement system that can simultaneously measure and analyze power components for both supply and demand. Voltage 8-channel and current 10-channel measurement is made through voltage and current sensors connected to the developed system, and power components such as reactive power, power factor and harmonics are calculated and measured by the DSP. The measured data are stored in a personal computer (PC) and a commercial program is then used for measurement data analysis and display. After voltage and current measurement accuracy revision using YOKOGAWA 2558, the developed system was tested using a programmable ac power source. The test results showed the accuracy of the developed system to be about 0.3 percent. Also, a simultaneous measurement field test of the developed system was implemented by application to the supply and demand side of the three-phase power system.

Micro-LIF Measurement in a Micro-channel Using an Micro Laser Light Sheet (마이크로 레이저 평면빔을 이용한 마이크로채널 내에서의 Micro-LIF 측정)

  • Yoon, Sang-Youl;Kim, Jae-Min;Kim, Su-Hun;Kim, Kyung-Chun
    • Proceedings of the KSME Conference
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    • pp.1540-1545
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    • 2004
  • Measurement of concentration fields in a micro-channel is the crucial technology in the area of Lab-on-a-chip to be used for various bio-chemical applications. It is wel-known that the only possible way to measure the concentration field in the micro-channel is using micro-LIF(Laser Induced Fluorescence) method. However, an accurate concentration field at a given cross plane in a micro-channel has not been made so far due to the limit of light illumination. The present study demonstrates a novel method to provide an ultra thin laser sheet beam having 5 microns thickness by a micro focus laser line generator. Nile Blue A was used as fluorescent dye for LIF measurement. The laser sheet beam illuminates an exact plane of concentration measurement in the micro-channel to increase the signal to noise ratio and reduce the depth uncertainty considerably.

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A Study On The Characteristics Of The Medium Voltage Power Distribution Line Channel By Wideband Channel Impulse Response Measurement Using PN Sequence (PN 시퀀스 방식의 광대역 임펄스 응답 측정을 통한 고압 배전선로 채널 특성 연구)

  • Oh Hui-Myoung;Choi Sung-Soo;Lee Jae-Jo;Kim Kwan-Ho;Whang Keum-Chan
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.54 no.1
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    • pp.56-60
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    • 2005
  • In the power-line communication(PLC) systems, the power line is a wired medium. However, the power line channel has the multi-path fading characteristics like the wireless channel in the wireless communication systems because it has the signal reflection and divergence by the impedance mismatching between many branch lines and loads. So the analysis of the multi-path characteristics is very important, and it has been doing by the several measurement methods for the impulse response between the transmitter and the receiver. PN sequence method has originally been used as a wideband impulse response measurement mettled for wireless channel, but it is recently being applied to not only the wireless channel but also the wired channel like the power line channel. This method is more useful and effective for the long distance communication channel like the medium voltage power distribution line with the multi-paths[1]. In this thesis, we have measured impulse response for the medium voltage power distribution line channel by the wideband measurement method using PN sequence, analytically studied the measured data and presented the results.

Development of Measurement System for Industrial Transportable Gamma Ray CT (이동 형 산업용 단층측정 장치를 위한 감마선 검출시스템 개발)

  • Kim, Jong-Bum;Jung, Sung-Hee;Moon, Jin-Ho
    • Journal of Radiation Industry
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    • v.6 no.3
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    • pp.231-237
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    • 2012
  • This paper introduces a gamma-ray measurement system for a transportable tomography which is applicable for an industrial process diagnosis. The gamma-ray measurement system consists of pulse mode operating 72 channel CsI detectors, main AMP-pulse shaper, single channel analyzer, counter and control PC. The CsI crystal is coupled with a PIN diode which is connected to an amplifier and pulse shaper. For a compact design, the amplifier and pulse shaping circuit are included in a single package. 36 sets of CsI detectors are connected to a multi-channel counter through single channel analyzers. A computer controls and collects data from two multi-channel counters. This configuration results in 72 channel counting system in total. The CT rotator and radiation measurement system are controlled by a PC with LabVIEW program. Tomographic data were measured for a phantom by the measurement system and transportable gamma-ray CT. From the experimental data image reconstructions were performed by ML-EM algorithm. The result showed that the CsI detector system can be a suitable component for transportable gamma-ray CT system.

Development of channel characteristics measurement system for Medium Voltage Power Line Grid (고압전력선 통신 채널 특성 측정 시스템 개발)

  • Lee, Jae-Jo;Lee, Won-Tae;Oh, Hui-Myoung;Kim, Kwan-Ho;Lee, Dae-Young
    • Proceedings of the KIEE Conference
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    • pp.2640-2642
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    • 2002
  • In this paper, we show the channel characteristics measurement system the frequency range up to 30MHz for medium voltage Power Line Grid. Power line channel characteristics are investigated by means of various measurement instruments. Measurement system consists of medium voltage coupler, impedance measurement part, noise measurement part, voltage sensing part and communication part. Measured data will be used for PLC channel modeling and PLC network system design.

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A Study on the Difference Method of Magnetic Resonance Signal Measurement when Using Multi-channel Coil and Parallel Imaging

  • Choi, Kwan-Woo;Lee, Ho-Beom;Son, Soon-Yong;Jeong, Mi-Ae
    • Journal of Magnetics
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    • v.22 no.2
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    • pp.220-226
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    • 2017
  • SNR (signal to ratio) is a criterion for providing objective information for evaluating the performance of a magnetic resonance imaging device, and is an important measurement standard for evaluating the quality of MR (Magnetic Resonance) image. The purpose of our study is to evaluate the correct SNR measurement for multi-channel coil and parallel imaging. As a result of research, we found that both T1 and T2 weighted images show the narrowest confidence interval of the method recommended by NEMA (The National Electrical manufacturers Association) 1 having a single measurement method, whereas the ACR (American College of Radiology) measurement method using a multi-channel coil and a parallel imaging technique shows the widest confidence interval. There is a significance in that we quantitatively verified the inaccurate problems of a signal to noise ratio using a ACR measurement method when using a multi-channel coil and a parallel imaging technique of which method does not satisfy the preconditions that researchers could overlook.

Implementation of Multi-Channel Power Components Measuremen System (다채널 전력분석시스템의 구현)

  • Lee, Myung-Un;Yoo, Jae-Geun;Lee, Sang-Ick;Cho, Myung-Hyun;Choe, Gyu-Ha
    • The Transactions of the Korean Institute of Power Electronics
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    • v.11 no.3
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    • pp.233-238
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    • 2006
  • In order to solve power disturbances, power components measurement for both supply and demand side of power system must be implemented. This paper proposed a DSP (Digital Signal Processor)-based multi-channel (voltage 8-channel and current 10-channel) power components measurement system that simultaneously can measure and analyze power components for both supply md demand side. After voltage and current measurement accuracy revision using YOKOGAWA 2558, the developed system was tested in the field.

Distribution Channel Performance Measurement: Valid Measures From Customers' Perspective

  • Kim, Sang-Youl
    • Journal of Navigation and Port Research
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    • v.32 no.2
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    • pp.141-148
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    • 2008
  • This paper is structured into three main parts and a conclusion. The main section provide definitions of efficiency, effectiveness and performance in terms of the distribution channel, followed by a review of related performance measurement, before discussing difficulties of measurement. According to the theoretical approach, it appears that key theroretical issues are centered around customer service, logistics excellence, time compression, the use of IT, and a move towards integrated logistics. The empirical approach shows that in the past, various financial performance indicators were regarded as relevant management information. However, today, management needs additional performance indicators. Therefore, external assessments of effectiveness must be performed to measure customers' satisfaction with the physical flow of product through the distribution channel network. So, what is needed is to take previous normative and explorative research and progress through a framework by developing valid measures of distribution channel's effectiveness and efficiency, and identifying research methodologies suited to the data collection requirements.

A Surface Generation Velocity Measurement Technique Using the Buried Channel MOS Structure (Buried Channel MOS 구조를 이용한 표면생성속도 측정 방법)

  • 조성호;허연철;이종덕
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.29A no.7
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    • pp.56-63
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    • 1992
  • A measurement technique of the surface generation velocity S$_o$ using the BC(buried channel) MOS structure with shallow and low doped channel layer (BC MOS S$_o$ measurement technique) is presented and verified analytically and experimentally. Using this measurement technique, S$_o$ can be measured more accurately than that measured using the gate-controlled diode SS1oT measurement technique. When S$_o$ is measured for the two techniques from a BC MOS structure test patten with gate length of 171$\mu$m, the results are 0,66cm/sec and 0.28cm/sec for the former and the latter respectively.

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Design of an enhanced SIR measurement algorithm for WCDMA mobile station Modem (WCDMA 단말 모뎀을 위한 개선된 SIR 측정 알고리즘 설계)

  • Han, Jung-Su;Doo, Joo-Hyun;Choi, Hyung-Jin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.2A
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    • pp.51-60
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    • 2005
  • In this paper, we propose an enhanced SIR measurement algorithm for WCDMA mobile station modem. The proposed algorithm minimizes processing delay by applying velocity estimation-based channel estimator with IIR filter and reduces measured SIR offset by compensating attenuated signal power by using pilot channel(CPICH) in fading channel environment. To improve stability of SIR measurement, we also adopt an IIR filter which can properly reflect variation of fading channel in signal and interference power measurement. We prove that the proposed algorithm outperforms conventional SIR measurement algorithm in mean and jitter of measured SIR. Computer simulation shows that performance results using the proposed algorithm have improvement of approximately 8dB for measured mean and 2dB for measured jitter in the wireless mobile channel, especially in fast mobile speed environment.