• 제목/요약/키워드: Pre-Equalization

검색결과 56건 처리시간 0.028초

Bilateral 필터의 Sigma 편차를 이용한 차량 영상 Deblur 알고리즘 (Deblurring Algorithm for Vehicle Image Processing Using Sigma Variation of Bilateral Filter)

  • 손휘곤;김희석
    • 전기전자학회논문지
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    • 제19권2호
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    • pp.148-154
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    • 2015
  • 차량 전장시스템은 매 순간마다 정확한 인식을 통하여 사용자에게 정확한 경보를 전달해야 한다. 따라서 차량 영상 인식 알고리즘을 적용하기 위하여 빠른 전처리 시스템이 필요하다. 본 논문은 운전자 보조 시스템의 영상 처리를 목적으로 histogram equalization과 편차를 이용한 bilateral Filter를 사용하여 blur 영상을 보정하는 방법에 대해서 제안하였다. 제안한 시스템은 영상 스케일, 평활화, 노이즈 필터, 윤곽선 추출 순으로 총 5단계로 구성되며, bilateral filter의 과 값을 운전자 보조 시스템에서 나타나는 도로의 주행 현상에 적합하게 추출하여 10픽셀 이하의 blur를 기존의 방법들보다 빠르게 처리하였다. 실험 결과는 MATLAB을 사용하여 소요시간 및 PSNR을 구하였으며 기존의 방법과 비교하여 본 논문의 결과가 처리속도가 빠름을 입증하였다.

Adaptive Techniques for Joint Optimization of XTC and DFE Loop Gain in High-Speed I/O

  • Oh, Taehyoun;Harjani, Ramesh
    • ETRI Journal
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    • 제37권5호
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    • pp.906-916
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    • 2015
  • High-speed I/O channels require adaptive techniques to optimize the settings for filter tap weights at decision feedback equalization (DFE) read channels to compensate for channel inter-symbol interference (ISI) and crosstalk from multiple adjacent channels. Both ISI and crosstalk tend to vary with channel length, process, and temperature variations. Individually optimizing parameters such as those just mentioned leads to suboptimal solutions. We propose a joint optimization technique for crosstalk cancellation (XTC) at DFE to compensate for both ISI and XTC in high-speed I/O channels. The technique is used to compensate for between 15.7 dB and 19.7 dB of channel loss combined with a variety of crosstalk strengths from $60mV_{p-p}$ to $180mV_{p-p}$ adaptively, where the transmit non-return-to-zero signal amplitude is a constant $500mV_{p-p}$.

마스크 히스토그램 평준화를 이용한 T형 용접너트 자동 선별시스템의 비전검사기 성능개선에 관한 연구 (A Study on Improvement of Vision Inspector for T Type Welding nut auto Sorting System using a Masked Histogram Equalization)

  • 허태원;송한림
    • 전자공학회논문지
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    • 제49권9호
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    • pp.353-361
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    • 2012
  • 본 논문에서는 트림 T형 용접너트의 생산 시스템 중 불량품을 자동으로 선별할 수 있는 자동 비전 선별기의 성능 개선에 관한 방법을 제안한다. 자동 비전 선별기는 용접너트의 영상 신호에 대해 히스토그램을 활용한 경계 판별 및 나사산 검출, 이진 모폴로지 연산(Binary morphology operation)을 활용한 얼룩 검출 등의 기법을 활용한 것이다. 이 비전 선별기 운영에 있어 주된 문제는 컨베이어 벨트 상의 오일 등에 의한 오염에 따른 획득 영상의 화질 저하에 따른 오동작이다. 이를 해결하기 위해 배경 영상과 너트 영상의 구분을 위한 마스킹 기법을 사용하여, 너트 영상 부분에만 히스토그램 평준화를 이용하여 너트 영상부분의 대비를 높이는 전처리 과정을 도입하였다. 이를 통해 배경 부분에서 장비의 오염에 의해 추출되는 특징들의 영향을 없애고 획득 영상의 화질 저하에도 불구하고 오동작의 비율을 10 % 에서 0.2 % 로 낮출 수 있었다.

Kinetics of the Formation of Metalloporphyrins and the Catalytic Effect of Lead Ions and Hydrogen Ions

  • Qi, Yong;Pan, Ji Gang
    • Bulletin of the Korean Chemical Society
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    • 제35권11호
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    • pp.3313-3318
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    • 2014
  • The reaction mechanism of Lead ions catalyzing complexation reactions between TIPP and metal ions was investigated by researching the kinetics of the formation of metalloporphyrins by UV/Vis-spectra, and verified by exploring the formation of metalloporphyrins catalyzed by acetic acid. Kinetics studies suggested that the fluctuations of reaction rate indicated the formation of metalloporphyrin was step-wise, including the pre-equilibrium step (the coordination of the pyrrolenine nitrogens to $Mn^+$) and the rate-controlling step (the deprotonation of the pyrrole proton). In the pre-equalization step, a sitting-atop (SAT) structure formed first with the complexation between larger radius of $Pb^{2+}$ and TIPP, changed the activation, then $Pb^{2+}$ left with the smaller radius of metal ions attacking from the back of the porphyrin ring center. In the rate-controlling step, two pyrrole protons dissociated to restore a stable structure. This was verified by adding acetic acid at different reaction times.

연합고사에 의한 고교 신입생 배정방법에 관한 연구 -특히 선지원 . 후시험 배정제도를 중심으로- (A Study on the Method of Assigning Students to the High Schools by the Allied Entrance Examination. -Especially on the System of an Assignment for the Pre-Application and the Post-Examination. -)

  • 이철식;홍순태
    • 경영과학
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    • 제7권2호
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    • pp.22-42
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    • 1990
  • This paper deals with enhancement of the high school equalization assignment system to be executed by the allied entrance examination after the applicants graduated from their middle schools. In prevailing opinion, because educational demander's will has not been considered under the current system, it whose merits have been covered is required to be improved. If the application system of the entrance examination for the high schools will be returned, a situation that it will result in irregularity of the middle school education and in overheating entrance examination seems to appear explicitly. Since the averages of the allied entrance examination score of all the high schools, achieved by the equalization-application nearest assignment system which is named by writers of this paper, are equal, our system is good for maintaining the merits of the current system. More than 50% educational demander's will has been reflected by our system, so that we come to the conclusion that our system is excellent in all the systems verified up to now. Assigning students to the high school to make an average difference between three and five score, we expect that relection rate of the educational demander's will be increased more than 60%.

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A 1.5 Gbps Transceiver Chipset in 0.13-μm CMOS for Serial Digital Interface

  • Lee, Kyungmin;Kim, Seung-Hoon;Park, Sung Min
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제17권4호
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    • pp.552-560
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    • 2017
  • This paper presents a transceiver chipset realized in a $0.13-{\mu}m$ CMOS technology for serial digital interface of video data transmission, which compensates the electrical cable loss of 45 dB in maximum at 1.5 Gbps. For the purpose, the TX equips pre-emphasis in the main driver by utilizing a D-FF with clocks generated from a wide-range tuning PLL. In RX, two-stage continuous-time linear equalizers and a limiting amplifier are exploited as a front-end followed by a 1/8-rate CDR to retime the data with inherent 1:8 demultiplexing function. Measured results demonstrate data recovery from 270 Mbps to 1.5 Gbps. The TX consumes 104 mW from 1.2/3.3-V supplies and occupies the area of $1.485mm^2$, whereas the RX dissipate 133 mW from a 1.2-V supply and occupies the area of $1.44mm^2$.

A Practical Physical-Layer Network Coding for Fading Channels

  • Jung, Bang-Chul
    • Journal of information and communication convergence engineering
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    • 제8권6호
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    • pp.655-659
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    • 2010
  • In the conventional PNC scheme, the relay node requires simultaneous transmission of two source nodes with strict power control and carrier-phase matching between two received symbols. However, this pre-equalization process at source nodes is not practical in fading channels. In this letter, we propose a novel physical-layer network coding (PNC) scheme with log-likelihood ratio (LLR) conversion for fading channels, which utilizes not pre-equalizer at transmitters (source nodes) but joint detector at receiver (relay node). The proposed PNC requires only channel side information at the receiver (CSIR), which is far more practical assumption in fading channels. In addition, the proposed PNC scheme can use the conventional modulation scheme like M-QAM regardless of modulation order, while the conventional PNC scheme requires reconfiguration of modulation scheme at the source nodes for detection of the received signal at relay node. We consider the combination of the proposed PNC and channel coding, and find that the proposed PNC scheme is easily combined the linear channel codes such as turbo codes, LDPC, and convolutional codes.

컴퓨터비젼을 이용한 알루미늄 캔재 이어링률 자동 측정 시스템 개발 (Development of an Auto Measuring System for the Earing Rate of Aluminum CAN Using Computer Vision)

  • 이용중;김형조;이양범
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2003년도 춘계학술대회 논문집
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    • pp.288-292
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    • 2003
  • The main purpose of this paper is the development of the system which measures the earing rate of aluminum CAN with the CCD camera. In order to optimize imput image, the image object was segregated and the position of the image grasped. In the pre-processing the edges were detected by the Robert mask after improving the definition of image by the histogram equalization. The height of four each ear and angles which occur due to the characteristics of the aluminum CAN are measured manually with the digital vernier calipers in the industrial ground and in the case of the velocity, these require 30 seconds at least by three times measurement per height of one direction of the aluminum. But it took 0.02 seconds when this system was applied. Therefore this system is proven the satisfactory efficiency and reliability as compared to the control result of in industrial ground.

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사전등화를 이용하는 상향링크 MC-CDMA/TDD 시스템의 성능분석 (Performance Analysis of an Uplink MC-CDMA/TDD System with Pre-Equalization)

  • 남기호;오성근;선우명훈
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 하계종합학술대회 논문집 I
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    • pp.218-221
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    • 2003
  • 본 논문에서는 사전등화를 이용하는 상향링크 MC-CDMA(multicarrier-code division multiple access)/TDD(time division duplexing) 시스템에서 사전등화를 위한 상향링크 채널을 추정하는 방법들을 제안하고 시스템의 성능분석을 수행한다. 제안된 방법들에서는 하향링크 슬롯구간에서의 채널변화를 적절한 차수의 다항식으로 모델링하고, 이 다항식을 상향링크 슬롯구간으로 확장함으로써 상향링크 슬롯구간의 채널을 추정한다. 하향링크 슬롯구간에서의 채널변화는 MMSE(minimum mean squared error)curve fitting 방법이나 Lagrange 보간법 등이 사용되며 1차, 2차, 3차 다항식으로 근사화 된다. 성능지표로 정확도보다 시스템 성능이 중요 하므로 BER (bit error rate)을 사용한다. 다양한 시스템 및 채널환경에서의 모의실험 결과로부터 Lagrange 보간법은 하향링크 채널정보가 정확한 경우에는 MMSE 방법보다 성능이 다소 우수하지만 하향링크 채널추정 오류에 매우 민감하며, 2 차 다항식을 사용한 MMSE curve fitting 방법은 다양한 환경에서 우수한 성능을 가질 뿐만 아니라 채널추정 오류에도 매우 강인함을 알 수 있다.

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