• 제목/요약/키워드: 전자검출기

검색결과 1,005건 처리시간 0.026초

A VLSI Design for High-speed Data Processing of Differential Phase Detectors with Decision Feedback (결정 궤환 구조를 갖는 차동 위상 검출기의 고속 데이터 처리를 위한 VLSI 설계)

  • Kim, Chang-Gon;Jeong, Jeong-Hwa
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • 제39권5호
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    • pp.74-86
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    • 2002
  • This paper proposes a VLSI architecture for high-speed data processing of the differential phase detectors with the decision feedback. To improve the BER performance of the conventional differential phase detection, DF-DPD, DPD-RGPR and DFDPD-SA have been proposed. These detection methods have the architecture feedbacking the detected phase to reduce the noise of the previous symbol as phase reference. However, the feedback of the detected phase results in lower data processing speed than that of the conventional differential phase detection. In this paper, the VLSI architecture was proposed for high-speed data processing of the differential phase detectors with decision feedback. The Proposed architecture has the pre-calculation method to previously calculate the results on 'N'th step at 'M-1'th step and the pre-decision feedback method to previously feedback the predicted phases at 'M-1'th step. The architecture proposed in this paper was implemented to RTL using VHDL. The simulation results show that the Proposed architecture obtains the high-speed data processing.

A Speed-up Method of HOG Pedestrian Detector in Advanced SIMD Architecture (Advanced SIMD 아키텍처에서의 HOG 보행자 검출기 고속화 방법)

  • Kwon, Ki-Pyo;Lee, Jae-Heung
    • Journal of IKEEE
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    • 제18권1호
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    • pp.106-113
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    • 2014
  • A pedestrian detector can be applied for various purposes such as monitoring or counting the number of people in some place, or detecting the people plunging in the driveway. There was a lot of related research. But, the detection speed is slow in embedded system because of the limited computing power. An algorithm for fast pedestrian detector using HOG in ARM SIMD architecture is presented in this paper. There is a way to quickly remove the background of image and to improve the detection speed using NEON parallel technique. When we tested with INRIA Person Dataset, the proposed pedestrian detector improves the speed by 3.01 times than previous one.

Performance Improvements of Energy Detector for Spectrum Sensing in Cognitive Radio Environments: Verification using Multiple Antennas (인지무선환경에서 스펙트럼 센싱을 위한 에너지 검출기의 성능개선: 다중안테나를 이용한 확인과정)

  • Baek, Jun-Ho;Oh, Hyeong-Joo;Lee, Jong-Hwan;Hwang, Seung-Hoon
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • 제45권4호
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    • pp.38-42
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    • 2008
  • In this paper, we propose a new structure for spectrum sensing which employs multiples energy detectors in multiple antenna system in order to improve its reliability. The performance is analyzed by simulation and compared to that of the conventional energy detector. The simulation results shows that the performance of the proposed scheme is much better than that of the conventional one. Additionally, the performance of is described in terms of ROC curve.

Dual-Mode Reference-less Clock Data Recovery Algorithm (이중 모드의 기준 클록을 사용하지 않는 클록 데이터 복원 회로 알고리즘)

  • Kwon, Ki-Won;Jin, Ja-Hoon;Chun, Jung-Hoon
    • Journal of the Institute of Electronics and Information Engineers
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    • 제53권5호
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    • pp.77-86
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    • 2016
  • This paper describes a dual-mode reference-less CDR(Clock Data Recovery) operating at full / half-rate and its operation algorithm. Proposed reference-less CDR consists of a frequency detector, a phase detector, a charge pump, a loop filter, a voltage controlled oscillator, and a digital block. The frequency and phase detectors operate at both full / half-rate for dual-mode operation and especially the frequency detector is capable of detecting the difference between data rate and clock frequency in the dead zone of general frequency detectors. Dual-mode reference-less CDR with the proposed algorithm can recover the data and clock within 1.2-1.3 us and operates reliably at both full-rate (2.7 Gb/s) and half-rate (5.4 Gb/s) with 0.5-UI input jitter.

Behavior of an Automatic Pacemaker Sensing Algorithm for Single-Pass VDD Atrial Electrograms (Single-Pass VDD 심파를 위한 자동화된 심장 박동기 탈분극파 검출 알고리즘의 효용성)

  • Kim, Jung-Kuk;Lee, Seung-Han;Huh, Woong
    • Journal of IKEEE
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    • 제5권2호
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    • pp.182-189
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    • 2001
  • Single-pass VDD pacemakers have been used as a result of simple implantation procedures and generally reliable atrial tracking that ensures an A-V sequence pacing. However, there is a controversy over their reliabilities of atrial tracking. As a new sensing method for reliable atrial tracking, a simple automatic pacemaker sensing algorithm was implemented and evaluated to validate its benefits in sensing depolarization waves of Single-pass VDD atrial electrograms. The automatic sensing algorithm had a predetermined sensing dynamic range and the sensitivity level was controlled as 50% of the average of two most recently sensed intrinsic amplitudes. The behavior of the automatic sensing algorithm in the Single-pass VDD atrial electrograms was analyzed and characterized. It was observed that the automatic sensing algorithm was more effective than a conventional fixed threshold method to accurately detect and track p-waves in Single-pass VDD electrograms.

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The Electron Detector in Scanning Electron Microscope (주사전자현미경용 전자검출기)

  • 이상욱;전종업;한상훈
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 한국공작기계학회 2004년도 춘계학술대회 논문집
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    • pp.513-517
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    • 2004
  • 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. In this article, electron beam-specimen interactions, the detection principle of secondary electrons and backscattered electrons, and the structure of a conventional detector are described. The structure of an experimental apparatus for the future study on our hopeful novel electron detector is presented as well.

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Design and Manufacture of an Electron Detector for Scanning Electron Microscope (주사전자현미경용 전자검출기의 설계 및 제작)

  • Jeon, Jong-Up;Kim, Ji-Won
    • Journal of the Korean Society for Precision Engineering
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    • 제25권4호
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    • pp.53-60
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    • 2008
  • Electron detectors used in scanning electron microscope accept electrons emitted from the specimen and convert them to an electrical signal that, after amplification, is used to modulate the gray-level intensities on a cathode ray tube, producing an image of the specimen. Electron detector is one of the key components dominating the performance of scanning electron microscope so that the development of electron detectors having high performance is indispensable to acquire high quality images using scanning electron microscope. In this paper, we designed and manufactured an electron detector and conducted a couple of image capture experiments using it. In particular, scintillator which generates light photons when it is struck by high-energy electrons was manufactured and experimental studies on the optimization of manufacturing condition was carried out. From experiments to evaluate the performance of our detector, it was verified that the performance of our detector is equivalent to or better than that of the conventional one.

Vector Control of Wound Rotor Induction Motor without Speed Sensor (속도검출기가 없는 권선형 유도전동기의 벡터제어)

  • 이홍희;배정용
    • Proceedings of the KIPE Conference
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    • 전력전자학회 1999년도 전력전자학술대회 논문집
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    • pp.514-517
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    • 1999
  • 산업 현장에서 널리 사용되고 있는 권선형 유도전동기의 완전한 벡터제어를 속도 검출기를 사용하지 않고 슬립 주파수를 추정하여 구현할 수 있는 알고리즘을 제안했다. 기존의 센서리스 벡터제어 알고리즘의 전동기의 저항의 변동에 대하여 아주 민감하지만 본 논문에서 제안된 알고리즘은 여자 전류 및 슬립주파수 측정에 전동기 2차 저항을 필요로 하지 않아 전동기 정수 변동으로 인한 벡터제어의 불완전함을 제거했다. 시뮬레이션을 통하여 제안된 알고리즘의 우수한 특성과 그 타당성을 확인을 하였다.

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High Efficient Viola-Jones Detection Framework for Real-Time Object Detection (실시간 물체 검출을 위한 고효율 Viola-Jones 검출 프레임워크)

  • Park, Byeong-Ju;Lee, Jae-Heung
    • Journal of IKEEE
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    • 제18권1호
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    • pp.1-7
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    • 2014
  • In this paper, we suggest an improved Viola-Jones detection framework for the efficient feature selection and the fast rejection method of the sub-window. Our object detector has low computational complexity because it rejects sub-windows until specific threshold. Owing to using same framework, detection performance is same with the existing Viola-Jones detector. We measure the number of average feature calculation about MIT-CMU test set. As a result of the experiment, the number of average feature calculation is reduced to 45.5% and the detection speed is improved about 58.5% compared with the previous algorithm.

Image Acquisition Study of Maximal Scintillation Pixel Array using Light Guide (광가이드를 사용한 최대 섬광 픽셀 배열의 영상 획득 연구)

  • Lee, Seung-Jae
    • Journal of the Korean Society of Radiology
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    • 제16권3호
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    • pp.249-255
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    • 2022
  • Positron emission tomography for small animals has very high spatial resolution for imaging very small organs. To achieve good spatial resolution, the system must be constructed using very small scintillation pixels. When a detector is constructed using very small scintillation pixels, the size of the applicable array varies depending on the photosensor pixel. In a previous study, a study was conducted to find the maximum scintillation pixel arrangement according to the size of the photosensor. In this study, a detector with a light guide was designed to configure the detector using a more extended array of scintillation pixels, and try to find the maximum arrangement in which all scintillation pixels are imaged. The detector was designed using DETECT2000, which can simulate a detector made of a scintillator. Simulations were performed by configuring the detectors from an 11 × 11 scintillation pixel array to a 16 × 16 array. After obtaining a flood image by collecting the light generated from the scintillation pixel with a photosensor, the largest arrangement without overlap was found through image analysis. As a result, the largest arrangement in which all scintillation pixels could be distinguished without overlapping was a 15 × 15 arrangement.