• Title/Summary/Keyword: detector

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A Peak Detector for Variable Frequency Three-Phase Sinusoidal Signals (가변주파수 3상 정현파 신호의 최대전압 검출기)

  • 김홍렬
    • Journal of Advanced Marine Engineering and Technology
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    • v.23 no.2
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    • pp.210-215
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    • 1999
  • The proposed detector is consists of three-phase sinusoidal signal generator and peak detector. This peak detector can detect the peak voltage value at the state of variable frequency. In experi-ment three-phase sinusoidal signals are generated from D/A converter using IBM PC and deliv-ered to the peak detector. Each signals are squared by multiplier and summed up Peak value is the square root of summed value extracted by square root circuit.

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A Clock Frequency Detector for Improving Certainty of the Embedded System (임베디드 시스템의 정확성 향상을 위한 클럭 주파수 검출기)

  • Jeong, Gwanghyeon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.23 no.5
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    • pp.516-522
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    • 2020
  • In this paper, the frequency detector which detects the clock frequency of the embedded system is proposed and analyzed. The proposed frequency detector is consisted of filter and peak voltage detector. The clock signal is converted from square wave to triangular wave by the filter. The peak voltage of the triangular wave is determined according to the frequency response of filter. The peak voltage detector detects and holds the peak voltage of the signal. Moreover, the proposed clock frequency detector can detect the frequency within 1ms and it gives guarantee of real-time operation.

Performance Comparisons of some nonparametric detectors (몇가지 비모수 검파기의 성능 비교)

  • 김홍길;송익호;장태주;배진수
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 1996.06a
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    • pp.9-15
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    • 1996
  • In this paper, we propose a new detector based on the median-shift sign. We call it the median-shift sign (MSS) detector, which is an extension of the classical sign detector. We first analyze the problem of detecting a dc signal in noise of known probability density function (pdf). The MSS detector with the optimum median-shift value, the optimum MSS detector, performs better than the sign detector in Gaussian noise: it has the best performance among the detectors compared in Laplacian and Cauchy noise. It is shown that the MSS detectors with constant median-shift values are nearly equal to the optimum MSS detector. We also analyze the problem of detecting a dc signal when only partial information is available on the noise. The MSS detectors with constant median-shift values are almost equal to the sign detector in Gaussian noise: they perform better than the sign and Wilcoxon detectors for most signal ranges in Laplacian and Cauchy noise.

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Performance Analysis of an Anisotropic Magnetoresistive Sensor-Based Vehicle Detector (Anisotropic Magnetoresistive 센서를 이용한 차량 검지기의 성능분석)

  • Kang, Moon-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.3
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    • pp.598-604
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    • 2009
  • This paper proposes a vehicle detector with an anisotropic magnetoresistive (AMR) sensor and addresses experimental results to show the detector's performance. The detector consists of an AMR sensor and mechanical and electronic apparatuses. The AMR sensor, composed of four magnetoresistors, senses disturbance of the earth's magnetic field caused by a vehicle moving over the sensor and then produces an output indicative of the moving vehicle. This paper verifies performance of the detector on the basis of experimental results obtained from the field tests carried under the two traffic conditions on local highways in Korea. First, I show the vehicle counting performance on a low speed congested highway by comparing the vehicle counts measured by the detector with the exact counts. Second, both vehicle counts and average speeds calculated from the measured point-occupancy on another continuously free running highway are compared with the reference values obtained from a loop detector which has two independent loop coils, where I have used several performance indices including mean absolute percentage error (MAPE) to show the performance consistency between the two types of detectors.

Image Correction Method for Uncooled IR TECless Detector with Non-linear characteristics due to Temperature Change

  • Shin, Jung-Ho;Ye, Seong-Eun;Kim, Bo-Mee;Park, Chan
    • Journal of the Korea Society of Computer and Information
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    • v.22 no.10
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    • pp.19-26
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    • 2017
  • In this paper, we propose an efficient image equipment implementation for the detector characteristics of various detectors by analyzing un-cooled thermal detector that exhibits nonlinear changes due to external temperature effects. First, we explain Thermal Electric Cooler for un-cooled detector temperature control system and Non-image correction methode for IR system. Second, we present the results of a study on an efficient control technique that can minimize the deterioration of image quality by controlling a un-cooled thermal detector without a thermal electric cooler(TEC) inside. Third, we suggest Image Correction Methods for Uncooled IR TECless Detector with Non-linear characteristics due to Temperature Change. So, we analyze and present the results of Image correction methods for various un-cooled thermal detector.

Implementation of Lattice Reduction-aided Detector using GPU on SDR System (SDR 시스템에서 GPU를 사용한 Lattice Reduction-aided 검출기 구현)

  • Kim, Tae Hyun;Leem, Hyun Seok;Choi, Seung Won
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.7 no.3
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    • pp.55-61
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    • 2011
  • This paper presents an implementation of Lattice Reduction (LR)-aided detector for Multiple-Input Multiple-Output (MIMO) system using Graphics Processing Unit (GPU). GPU is a parallel processor which has a number of Arithmetic Logic Units (ALUs), thus, it can minimize the operation time of LR algorithm through the parallelization using multiple threads in the GPU. Through the implemented LR-aided detector, we verify that the LR-aided detector operates a lot faster than Maximum Likelihood (ML) detector. The implemented LR-aided detector has been applied to WiMAX system to show the feasibility of its real-time processing. In addition, we demonstrate that the processing time can be reduced at the cost of 3dB SNR loss by limiting the repeating loop in Lenstra-Lenstra-Lovasz (LLL) algorithm which is frequently used in LR-aided detector.

A Study on the Secondary Electron Detector for use in Scanning Electron Microscope (SEM용 전자 검출기의 설계 및 제작)

  • Lee SangUk;Jeon Jong Up;Park KiTae;Park Kyu Yeol
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2005.05a
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    • pp.9-14
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    • 2005
  • The nature of the signals collected by an SEM(Scanning Electron Microscope) in order to form images are all dependent on the detector used to collect them, and the quality of an acquired image is strongly influenced by detector performance. Therefore, the development of detector with high performance is very important in pulling up the resolution of SEM This study presents the secondary electron detector for use in scanning electron microscope, electric circuit and I/V conversion circuit for driving that detector.

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Image enhancement using software quadrature detector (소프트웨어 쿼드러춰 검출기를 이용한 영상개선)

  • Ko, Dae-Sik;Kim, Hyun;Jun, Kye-Suk
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.5
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    • pp.111-116
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    • 1998
  • In this paper, we proposed method of performance enhancement of the ultrasonic imaging system using quadrature detector and implementation of the software quandrature detector. Since the quadrature detector is more sensitive than the enbelope detector of the conventional ultrasonic imaging syustem, we are able to achieve the contrast enhnacement. Although hardware quadrature detector is able to process high sped data acquisition, its hardware has complexity. In order to show the performance of the software quadrature we have constructed ultrasonic signal processing system and obtained the reflected signal from the aluminum specimen using A/D convertor. Our experimental results showed that image of the quadrature detector is better than that of the envelope detector.

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Field Test and Evaluation for a Wireless Vehicle Detector with Two Anisotropic Magneto-Resistive Sensors (2개의 AMR 센서를 이용한 무선 차량 검지기에 대한 현장시험 및 평가)

  • Kang, Moon-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.3
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    • pp.600-605
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    • 2011
  • This paper shows field test and evaluation results for a wireless vehicle detector with anisotropic magneto-resistive (AMR) sensors. The detector consists of two AMR sensors and mechanical and electronic apparatuses. The AMR sensor senses disturbance of the earth magnetic field caused by a vehicle moving over the sensor and then produces an output indicative of the moving vehicle. In this paper, vehicle speeds are calculated by using two AMR sensors fixed on a board, with constant distance. To test and evaluate the accuracy of the detector in real traffic situations, the detector was installed on a local highway and vehicle speeds and volumes were measured both in a free running and a highly congested traffic. The measurements from the detector are compared with the reference measurements obtained from a traffic camera with the Mean Absolute Percentage Errors (MAPE), which has proved the usefulness of the detector in the field.