• Title/Summary/Keyword: digital signal process

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A Depth Creation Method Using Frequency Based Focus/Defocus Analysis In Image (영상에서 주파수 기반의 초점/비초점 분석을 이용한 깊이 지도 생성 기법)

  • Lee, Seung Kap;Park, Young Soo;Lee, Sang Hun
    • Journal of Digital Convergence
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    • v.12 no.11
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    • pp.309-316
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    • 2014
  • In this paper, we propose an efficient detph map creation method using Graph Cut and Discrete Wavelet Transform. First, we have segmented the original image by using Graph Cut to process with its each areas. After that, the information which describes segmented areas of original image have been created by proposed labeling method for segmented areas. And then, we have created four subbands which contain the original image's frequency information. Finally, the depth map have been created by frequency map which made with HH, HL subbands and depth information calculation along the each segmented areas. The proposed method can perform efficient depth map creation process because of dynamic allocation using depth information. We also have tested the proposed method using PSNR(Peak Signal to Noise Ratio) method to evaluate ours.

Design of a BLDC Servo Motor Control System for the Auto Process of Assembly and Supply (자동 조립 및 공급을 위한 BLDC 서보 전동기 제어시스템 설계)

  • Sim, Dong-Seok;Choi, Jung-Keyng
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.5
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    • pp.1095-1101
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    • 2012
  • This paper presents a design of a BLDC servo motor control system for the auto process of assembly and supply using DSP(Digital Signal Processor) controller and IGBT driver. The assembly and supply auto processing system needs torque, speed, position control of servo motor for variable action. This paper implements those servo control with vector control and space vector PWM(Pulse Width Modulation) technique. As CPU of controller, TMS320F240 DSP was adopted because it has PWM waveform generator, A/D converter, SPI(Serial Peripheral Interface) port and many input/output port etc. This control system consists of 3-level hierarchy structure that main host PC manages three sub DSP system which transfer downward command and are monitoring the states of end servo controllers. Each sub DSP system operates eight BLDC servo controllers which control BLDC motor using DSP and IPM. Between host system and sub DSP communicate with RS-422, between main processor and controller communicate with SPI port.

Noise Removal using Canny Edge Detection in AWGN Environments (AWGN 환경에서 캐니 에지 검출을 이용한 잡음 제거)

  • Kwon, Se-Ik;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.8
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    • pp.1540-1546
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    • 2017
  • Digital image processing is widely used in various fields including the military, medical, image recognition system, robot and commercial sectors. But in the process of acquiring and transmitting digital images, noise is generated by various external causes. There are various types of general noise depending on the cause and form, but AWGN and impulse noise is one of the leading methods. Removing noise during image processing is essential to the pre-treatment process such as segmentation, image recognition and characteristic extraction. As such, this paper suggests an algorithm that distinguishes the non-edge area and edge area using the Canny edge to apply different filters to different areas in order to effectively remove noise from the image. To verify the effectiveness of the suggested algorithm, it was compared against existing methods using zoom images, edge images and PSNR(peak signal to noise ratio).

Desing of VR Contents for Visual Function Enhancement (VR 기반 시기능 강화 콘텐츠 설계 및 제작)

  • Yong-Ju Kim;Sang-Joong Jung
    • Journal of the Institute of Convergence Signal Processing
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    • v.23 no.2
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    • pp.70-75
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    • 2022
  • With the spread of various digital devices, devices have become commonplace in modern society. Moreover, due to the increase in device usage and online learning while staying indoors during the COVID-19 pandemic, symptoms such as an increase in myopia in children due to eye fatigue, an increase in young presbyopia, and dry eye syndrome are increasing, and now people are paying attention to eye health. This is different from before. There are various prescriptions for eye health, but in this paper, we would like to propose a training method for enhancing visual function using VR contents. The analog methods of the existing teaching aids for visual function reinforcement training were planned and produced as digital contents, and VR-based training contents were selected from among the various methods carried out with teaching aids at the visual function training center, which can be made into contents. was developed with In the training process for each content, it was proposed to apply eye tracking to the VR device in order to give the user feedback on their participation in the training so that the management and concentration of the training process could be analyzed.

A Study on Filter Algorithm to Remove Mixed Noise (복합잡음 제거를 위한 필터 알고리즘에 관한 연구)

  • Kwon, Se-Ik;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.05a
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    • pp.281-284
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    • 2015
  • Digital image processing is utilized in various application fields by rapid development of memory cell. However, the noise occurs with various causes in the process of data processing process and various methods have been studied in order to remove such noises. In general, the image is damaged by the mixed noise which has different characteristics each other. This paper proposed a filter algorithm which processes the data according to shape of noise in order to mitigate the impact of the mixed noise added to the image. In addition, this paper compared this filter algorithm with the current methods and used PSNR(peak signal to noise ratio) as a criterion of judgment.

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Analysis of Adaptive Digital Signal Processing for Anti-Jamming GPS System (Anti-Jamming GPS 시스템을 위한 적응형 디지털 신호 처리에 관한 분석)

  • Han, Jung-Su;Kim, Seok-Joong;Kim, Hyun-Do;Choi, Hyung-Jin;Kim, Ki-Yun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.8C
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    • pp.745-757
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    • 2007
  • In this paper, we propose a design of GPS anti-jamming system and its operational method, which can effectively suppress interference and jamming signals induced in GPS receiver. The 7-array antenna used in the proposed system is composed of conventional 6 equi-spaced circular elements with one element on the center of antenna and can be efficiently operated under power-constrained conditions. Futhermore, in this paper, we analyze the structure and complexity of STAP and SFAP which are well known techniques in adaptive array antenna signal processing, and we compare the BER performances between STAP and SFAP in various jamming environment based on the same complexity.

A Low Power Current-Steering DAC Selecting Clock Enable Signal (선택적으로 클럭 신호를 입력하는 저 전력 전류구동 디지털-아날로그 변환기)

  • Yang, Byung-Do;Min, Jae-Joong
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.48 no.10
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    • pp.39-45
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    • 2011
  • This paper proposes a low power current-steering 10-bit DAC selecting clock enable signal. The proposed DAC reduces the clock power by cutting the clock signal to the current-source cells in wihich the data will not be changed. The proposed DAC was implemented using a 0.13${\mu}m$ CMOS process with $V_{DD}=1.2V$. Its core area is 0.21$mm^2$. It consumes 4.46mW at 1MHz signal frequency and 200MHz sampling rate. The clock power is reduced to 30.9% and 36.2% of a conventional DAC at 1.25MHz and 10MHz signal frequencies, respectively. The measured SFDRs are 72.8dB and 56.1dB at 1MHz and 50MHz signal frequencies, respectively.

A Study on The Correction of The Channel Equalizer Decision Error Using Channel Estimator (채널추정기를 이용한 등화기 결정오류 정정 알고리즘에 관한 연구)

  • Kim, Seon-Woong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.8
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    • pp.18-24
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    • 2017
  • The process of transmitting messages through a medium with a limited bandwidth or channel dispersion inevitably involves signal distortion and noise influxes, resulting in the degradation of transmission quality due to the inter-symbol interference and additional noise, which increases the error rate of the received symbols. The main role of the equalizer is to remove the channel distortion and noise from the received signal to recover the transmitted messages. A number of studies on the equalizer composed of a combination of linear filter and error control coding have shown that they played a key role in enhancing the transmission efficiency, which is essential for digital communication. This paper proposes a new algorithm to correct the residual symbol errors in the message signal. In general, equalizer performance improvement algorithms were developed to improve the initial convergence speed or steady-state error. In this paper, however, the equalizer input signal was reconstructed using the equalizer decision symbols and the channel estimates to directly correct the decision errors by analyzing the statistical characteristics of the difference signal between the actual received signal and the reconstructed signal.

Development of LED Traffic Light Lens with snow removing function (제설 기능을 갖는 LED 신호등 렌즈 개발)

  • Lee, Dongeun;Seol, Dongyoul
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.13 no.4
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    • pp.41-48
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    • 2017
  • It is necessary to develop an LED traffic light lens having a snow removal function capable of clearly providing a traffic signal to the driver even when a traffic light is blurred due to heavy snow and wind in the winter season. This study is focused on the research and development of the traffic light lens in the process of developing the LED traffic light with the snow removal function. In the developed traffic light lens, instead of attaching the film heater, the coated nichrome wire was wound into a coil shape and inserted directly into the groove in the lens. The developed heater system facilitates the insertion of the heating wire with high elasticity into a curved lens and can provide a sufficient heat without deformation of the PC lens. The proposed traffic lights were tested in various external environments and the test results showed that complete snow removal is possible without tunnel effect.

Development of Target-Controlled Infusion system in Plasma Concentration. PART2: Design and Evaluation (혈중 목표 농도 자동 조절기(TCI) 개발 PART2: 시스템 구현 및 평가)

  • 안재목
    • Journal of Biomedical Engineering Research
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    • v.24 no.1
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    • pp.45-53
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    • 2003
  • Based on the 4-compartmental pharmacokinetic model developed in PART1, target-controlled infusion(TCI) pump system was designed and evaluated. The TCI system consists of digital board including microcontroller and digital signal process(DSP), analog board, motor-driven actuator, user friendly interface, power management and controller. It provides two modes according to the drugs: plasma target concentration and effect target concentration. Anaesthetist controls the depth of anaesthesia for patients by adjusting the required concentration to maintain both plasma and effect site in drug concentration. The data estimated in DSP include infusion rate, initial load dose, and rotation number of motor encoder. During TCI operation, plasma concentration. effect site concentration, awaken concentration, context-sensitive decrement time and system error information are displayed in real time. Li-ion battery guarantees above 2 hours without power line failure. For high reliability of the system, two microprocessors were used to perform independent functions for both pharmacokinetic algorithm and motor control strategy.