• Title/Summary/Keyword: A-scan signal

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Efficient deinterlacing method considering continuity of edge direction (에지 방향의 연속성을 고려한 효과적인 디인터레이싱 기법)

  • Choi, Seung-yeop;Baek, Min-gyu;Jeng, Jae-chang
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2013.11a
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    • pp.233-236
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    • 2013
  • As analog broadcast has replaced digital broadcast and HDTV broadcast has settled as a standard of broadcast system in Korea, most of broadcast in Korea send interlaced signal. For TV uses interlaced scan order, deinterlacing which converts interlaced signal into progressive signal has remain important. In this paper, efficient deinterlacing method considering continuity of edge direction is proposed. Deinterlacing along with the dege of an object is one of the main issue for better visual quality. Thus, an algorithm introduced in this paper consider not only the edge of object but continuity so that a better result is drawn forth. The result shows that the proposed algorithm excels comparing with conventional algorithms.

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Minimizing MR Gradient Artefacts on ECG Signals for Cardiac Gating based on an Adaptive Digital Filter (적응 디지털 필터 기반의 MRI Cardiac Gating을 위한 심전도 신호의 MR Gradient 잡음 최소화 방법)

  • Park, Ho-Dong;Jang, Bong-Ryeol;Lee, Kyoung-Joung
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.817-818
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    • 2006
  • In Magnetic Resonance Imaging(MRI), the QRS complex of ECG is used as a trigger signal for MRI scan. But, gradient and RF(radio frequency) artifacts which are caused to static and dynamic field in MRI scanner cause interference in the ECG. Also, the signal shape of theses artifacts can be similar to the QRS-complex, causing possible misinterpretation during patient monitoring and false gating of the MRI. In case of using general FIR or IIR band-pass filters for minimizing the artifacts, artifact-reduction-ratio is not excellent. So, an adaptive real-time digital filter is proposed for reduction of noise by gradient and RF(radio frequency) artifacts. The proposed filter for MRI-Gating is based on the noise-canceller with NLMS(Normalized Least Mean Square) algorithm. The reference signals of the adaptive noise canceller are a combination of the noisy three channel ECG signals. In conclusions, the proposed method showed the acceptable quality of ECG signal with sufficient SNR for gating the MRI and possibility of real time implementation.

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A Study on Locational Control of Motion Ghost in Magnetic Imaging System (자기공명영상장치(磁氣共鳴映像裝置)에서 움직임허상(虛像)의 위치제어(位置制御)에 관(關)한 연구(硏究))

  • Lee, Who-Min
    • Journal of radiological science and technology
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    • v.16 no.2
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    • pp.19-26
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    • 1993
  • Magnetic Resonance Image represents three-dimensional diagnostic imaging technique using both nuclear magnetic resonance phenomenon and computer. Compared with computed tomography (CT), MRI have advantages harmless to patient's body, three-dimensional image with high resolution and disadvantages long data acquisition time because of long T1 relaxation time, relatively low signal to noise ratio, high cost of setting, also. As physiologic motion of tissue results in motion ghost in MRI, high 2.0Tesla make improve low signal to noise ratio. This study have aim to improve image quality with controling motion ghost of tissue. Supposing a moving pixel in constant frequency, one pixel make two ghosts which are same size and different anti-phase. So, this study will show adjust parameter on locational control of motion ghost. Author made moving phantom replaced by respiratory movement of human, researched change of motion frequency, FOV by location shift, and them decided optimal FOV (field of view). The results are as follows: 1. The frequency content of the motion determines how far the image always appear in phase-encoding direction, the morphology of the ghost image is characteristic of the direction of the motion and its amplitude. 2. Double FOV of fixed signal object for locational control of motion ghost is recommended. Decreasement of spatial resolution by increasing FOV can compensate on increasing of matrix in spite of scan time increasement.

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Fast Motion Estimation Algorithms Through Adaptive Application of the Hadamard Transform (하다마드 변환의 적응적 적용을 이용한 고속 움직임 예측 알고리즘)

  • Lee, Hyuk;Kim, Jong-Ho;Jin, Soon-Jong;Jeong, Je-Chang
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.8C
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    • pp.712-719
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    • 2007
  • In this paper, we propose a new, effective, fast motion estimation algorithms using $4{\times}4$ pixels Hadamard transform. The Hadamard transform has the advantage of simplicity because it uses only addition and subtraction. Motion estimation is composed of three stages. First, it should be decided whether to terminate the search early and use a previous motion vector with DC(Direct Current) coefficients. Then the adaptive matching scan order for motion estimation should be determined according to the image complexity using AC(Alternating Current) coefficients. Experimentally, we adapted this algorithms to MVFAST and PMVFAST algorithms, and the proposed algorithms turn out to be very efficient in terms of computational speed while remaining almost the same in terms of PSNR(Peak Signal-to-Noise Ratio) compared to MVFAST and PMVFAST algorithms.

A Eukaryotic Gene Structure Prediction Program Using Duration HMM (Duration HMM을 이용한 진핵생물 유전자 예측 프로그램 개발)

  • Tae, Hong-Seok;Park, Gi-Jeong
    • Korean Journal of Microbiology
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    • v.39 no.4
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    • pp.207-215
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    • 2003
  • Gene structure prediction, which is to predict protein coding regions in a given nucleotide sequence, is the most important process in annotating genes and greatly affects gene analysis and genome annotation. As eukaryotic genes have more complicated stuructures in DNA sequences than those of prokaryotic genes, analysis programs for eukaryotic gene structure prediction have more diverse and more complicated computational models. We have developed EGSP, a eukaryotic gene structure program, using duration hidden markov model. The program consists of two major processes, one of which is a training process to produce parameter values from training data sets and the other of which is to predict protein coding regions based on the parameter values. The program predicts multiple genes rather than a single gene from a DNA sequence. A few computational models were implemented to detect signal pattern and their scanning efficiency was tested. Prediction performance was calculated and was compared with those of a few commonly used programs, GenScan, GeneID and Morgan based on a few criteria. The results show that the program can be practically used as a stand-alone program and a module in a system. For gene prediction of eukaryotic microbial genomes, training and prediction analysis was done with Saccharomyces chromosomes and the result shows the program is currently practically applicable to real eukaryotic microbial genomes.

Development of Vehicle Side Collision Avoidance System with Virtual Driving Environments (가상주행환경에서의 측면 충돌 방지시스템 개발)

  • Yoon, Moon Young;Choi, Jung Kwang;Jung, Jae Eup;Boo, Kwang Seok;Kim, Heung Seob
    • Journal of the Korean Society for Precision Engineering
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    • v.30 no.2
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    • pp.164-170
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    • 2013
  • The latest vehicle yields a superior safety and reduction of driving burden by monitoring the driving state of vehicle and its environment with various sensors. To detect other vehicles and objects of the rear left and right-side blind spot area of driver, provide the information about a existence of objects inside the blind spot, and give a signal to avoid collision, this study proposes the intelligent outside rear-view mirror system. This study proposes SILS system with PreScan and Matlab/Simulink to verify practical applicability of developed BSDS. PreScan yields realistic driving environments and road conditions and vehicle model dynamics and collision warning is controlled by Matlab/Simulink.

Simulation of Target Detection using UV and IR Band Signals (UV와 IR 대역 신호를 이용한 표적 신호 검출 시뮬레이션)

  • Du, Gyeong-Su;O, Jeong-Su;Jang, Seong-Gap;Hong, Hyeon-Gi;Seo, Dong-Seon;Choe, Jong-Su
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.38 no.1
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    • pp.79-88
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    • 2001
  • The target such as aircraft operates flares to protect itself from the missile. In general, Infra-red(IR) flares that are hot bodies radiating energy considerably greater than it does, so cause the missile to guide the flare instead of the target. For a precise target tracking in spite of a presence of flares, therefore, the seeker should discriminate the target signal from various clutters including the flare and the background. In this paper, we simulated 2-color rosette scan seeker using IR and UV(UltraViolet) bands. In each wave band, we analyzed the radiant distributions of the target, the flare, and background. These results showed that a simultaneous process in two bands can detect precisely the target.

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Design and Implementation of PC Adapter Board and its Application Softwares for IrDA Communications (적외선 통신용 PC 어댑터와 응용 소프트웨어의 설계 및 구현)

  • 윤춘희;노선영;황민태
    • Journal of Korea Multimedia Society
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    • v.6 no.5
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    • pp.889-895
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    • 2003
  • In this paper, we develop a PC adapter board and application software that do not use mouse or keyboard but the infrared communication, which can control the operation remotely. The infrared communication adapter is made up of the infrared receiver part and the serial communication interface part. The infrared receiver part creates a suitable scan-code using the received signal from the infrared transmitter (remote-controller). The serial communication interface part transmits the scan-code to PC by a serial communication. We implement its application softwares to listen to music and see movies. We can control their operations such as play, stop, pause and volume control remotely.

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Adaptive Scanning Scheme for Mobile Broadband Wireless Networks based on the IEEE 802.16e Standard (802.16e 표준 기반 광대역 무선 이동 망을 위한 동적 스캐닝 기법)

  • Park, Jae-Sung;Lim, Yu-Jin
    • Journal of the Korea Society of Computer and Information
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    • v.13 no.4
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    • pp.151-159
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    • 2008
  • Mobile broadband wireless network is emerging as one of the hottest research areas due to technical advances, and the demands of users who wish to enjoy the same network experience on the move. In this paper, we investigate the handover process at the medium access control (MAC) layer in an IEEE 802.16e-based system. In particular, we identify problems concerned with the scan initiation Process called cell reselection and propose a received signal strength (RSS) estimation scheme to dynamically trigger a scanning process. We show how the RSS estimation scheme can timely initiate a scanning process by anticipating RSS values considering scan duration required.

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A Study on Radiation Dose and Image Quality according to CT Table Height in Brain CT (두부 CT 검사 시 테이블 높이에 따른 선량과 화질에 관한 연구)

  • Ki-Won Kim;Joo-Young Oh;Jung-Whan Min;Sang-Sun Lee;Young-Bong Lee;Kyung-Hwan Lim;Yun Yi
    • Journal of radiological science and technology
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    • v.46 no.2
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    • pp.99-106
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    • 2023
  • The height of the table should be considered important during computed tomography (CT) examination, but according to previous studies, not all radiology technologists set the table at the patient's center at the examination, which affects the exposure dose and image quality received by the patient. Therefore, this study intends to study the image quality exposure dose according to the height of the table to realize the optimal image quality and dose during the brain CT scan. The head phantom images were acquired using Philips Brilliance iCT 256. When the image was acquired, the table height was adjusted to 815, 865, 915, 965, 1015, and 1030 mm, respectively, and each scan was performed 3 times for each height. For the exposure dose measurement, optically stimulated luminescence dosimeter (OSLD) was attached to the front, side, eye, and thyroid gland of the head phantom. In the signal to noise ratio (SNR) measurement result, The SNR values for each table height were all lower than 915 mm. As a result of exposure dose, the exposure dose on each area increased as the table height decreased. The height of the table has a close relationship with the patient's radiation exposure dose in the CT scan.