• Title/Summary/Keyword: Digital signal

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Design and Experiment of a Micro Electronic System for Prediction of Alveolar-Gas Partial Pressures

  • Kim, Da-Jung;Chang, Keun-Shik;Kim, Sa-Ji;Park, Hye-Yun;Suh, Gee-Young
    • Journal of Biomedical Engineering Research
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    • v.31 no.3
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    • pp.187-193
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    • 2010
  • In this study we have designed and fabricated an inexpensive micro electronic system that we call Alvitek. It can indirectly but accurately predict and display the partial pressures of alveolar oxygen and carbon dioxide for the patients in the ICU of a hospital. Alvitek consists of both hardware part and software part. Performance of the system is tested by animal experiment with pigs for various $F_{t}e_{2}$ and RR(Respiratory Rate) values under the mechanical ventilation. The predicted alveolar gas partial pressures are cprpared with the approximate alveolar oxygen partial pressures easily calculated by the physician’s bedside formula. As a result, we have concluded that the relative error of A-$aDe_2$ calculated by the bedside formula grows seriously for lower $F_{t}e_{2}$ values. The present prediction method of Alvitek is henceforth believed very meaningful to the physicians. The system hardware and software are described in the text.

Image Enhancement Using Error Diffusion with APL in PDP (APL 적용 오차 확산법을 이용한 PDP 화질 개선)

  • Jang Soo-Wook;Pyo Se-Jin;Lee Sung-Hak;Sohng Kyu-Ik;Kim Eun-Su
    • Journal of Korea Multimedia Society
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    • v.8 no.10
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    • pp.1360-1368
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    • 2005
  • PDP is the flat panel display, suitable for high definition television because of large-sire and high-brightness. It has many advantages such as fast response, wide viewing angle, low weight, and simple manufacturing process for fabrication. However, there are some disadvantages and one of them is the image quality degradation, which is dependent on the digital signal processing. Although image quality of PDP is improving by many researches and experimentations, it still isn't as good as that of CRT because of various factors. One of them is worm-like pattern generated by an error diffusion process. And the worm-like pattern is severely increased after an APL process. An increased worm-like pattern occur a drop of resolution in image and a change of CCT according to each grayscale. In this paper, a method for improvement of image quality using the error diffusion which considers the APL process is proposed. In the proposed method, the APL process is performed before the error diffusion process. Simulation results showed that the proposed method has better performances for resolution in images and CCT uniformity according to each grayscale than the conventional method.

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Sound Monitoring System of Machining using the Statistical Features of Frequency Domain and Artificial Neural Network (주파수 영역의 통계적 특징과 인공신경망을 이용한 기계가공의 사운드 모니터링 시스템)

  • Lee, Kyeong-Min;Vununu, Caleb;Lee, Suk-Hwan;Kwon, Ki-Ryong
    • Journal of Korea Multimedia Society
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    • v.21 no.8
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    • pp.837-848
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    • 2018
  • Monitoring technology of machining has a long history since unmanned machining was introduced. Despite the long history, many researchers have presented new approaches continuously in this area. Sound based machine fault diagnosis is the process consisting of detecting automatically the damages that affect the machines by analyzing the sounds they produce during their operating time. The collected sound is corrupted by the surrounding work environment. Therefore, the most important part of the diagnosis is to find hidden elements inside the data that can represent the error pattern. This paper presents a feature extraction methodology that combines various digital signal processing and pattern recognition methods for the analysis of the sounds produced by tools. The magnitude spectrum of the sound is extracted using the Fourier analysis and the band-pass filter is applied to further characterize the data. Statistical functions are also used as input to the nonlinear classifier for the final response. The results prove that the proposed feature extraction method accurately captures the hidden patterns of the sound generated by the tool, unlike the conventional features. Therefore, it is shown that the proposed method can be applied to a sound based automatic diagnosis system.

Development of High Speed Peak-hold Circuit for Gamma-ray (감마선용 고속 피크홀드회로의 개발)

  • Choi, Ki-seong;Che, Gyu-shik
    • Journal of Advanced Navigation Technology
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    • v.20 no.6
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    • pp.612-616
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    • 2016
  • Gamma-ray must be detected and processed immedietely after generation of it in the circumstances where it exists. Software methology may be used to process randomly generated signals, but its memory size and processing time become large. By the way, the hardware circuit to detect randomly generated signals is generalized in industrial site, while those circuits are not able to answer to the cases whose amplitude are very small and also speed high. We researched and developed hardware based peak-hold circuit that is able to detect peaks of gamma-ray signals through direct reading out their values by ADC at the time of maximum reaching for the small amplitude and high speed signals, and proposed and estimated its results in this paper. This peak-hold circuit is adequate to use in the radiation circumstances in which the gamma-rays are heavy because its circuit can catch high speed signals efficiently without software signal processing supports.

An Optimal Implementation of Object Tracking Algorithm for DaVinci Processor-based Smart Camera (다빈치 프로세서 기반 스마트 카메라에서의 객체 추적 알고리즘의 최적 구현)

  • Lee, Byung-Eun;Nguyen, Thanh Binh;Chung, Sun-Tae
    • Proceedings of the Korea Contents Association Conference
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    • 2009.05a
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    • pp.17-22
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    • 2009
  • DaVinci processors are popular media processors for implementing embedded multimedia applications. They support dual core architecture: ARM9 core for video I/O handling as well as system management and peripheral handling, and DSP C64+ core for effective digital signal processing. In this paper, we propose our efforts for optimal implementation of object tracking algorithm in DaVinci-based smart camera which is being designed and implemented by our laboratory. The smart camera in this paper is supposed to support object detection, object tracking, object classification and detection of intrusion into surveillance regions and sending the detection event to remote clients using IP protocol. Object tracking algorithm is computationally expensive since it needs to process several procedures such as foreground mask extraction, foreground mask correction, connected component labeling, blob region calculation, object prediction, and etc. which require large amount of computation times. Thus, if it is not implemented optimally in Davinci-based processors, one cannot expect real-time performance of the smart camera.

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The Flame Color Analysis of Color Models for Fire Detection (화재검출을 위한 컬러모델의 화염색상 분석)

  • Lee, Hyun-Sul;Kim, Won-Ho
    • Journal of Satellite, Information and Communications
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    • v.8 no.3
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    • pp.52-57
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    • 2013
  • This paper describes the color comparison analysis of flame in each standard color model in order to propose the optimal color model for image processing based flame detection algorithm. Histogram intersection values were used to analyze the separation characteristics between color of flame and color of non-flame in each standard color model which are RGB, YCbCr, CIE Lab, HSV. Histogram intersection value in each color model and components is evaluated for objective comparison. The analyzed result shows that YCbCr color model is the most suitable for flame detection by average HI value of 0.0575. Among the 12 components of standard color models, each Cb, R, Cr component has respectively HI value of 0.0433, 0.0526, 0.0567 and they have shown the best flame separation characteristics.

Implementation of Digital Selective Calling Function for the Very High Frequency Radio telephone using the Automatic Identification System (선박자동식별장치를 이용한 초단파무선전화의 디지털선택호출 기능 구현)

  • Lee, Ju-Han;Yim, Jae-Hong;Lim, Jung-Gyun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.12
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    • pp.2232-2240
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    • 2017
  • IMO has made AIS and VHF mandatory for international sailing vessels through SOLAS, and korea if mandating specific vessels through the law for safety of vessels and the ship installation technology standards. However, due to various communication equipments and complicated usage method, malfunction occurs, and the response delay to the actual structure signal often causes human accidents. So recently, as a part of GMDSS modernization, maritime communication devices are attempting to interwork and integrate different types of marine communication system in order to construct a next generation maritime communication system. In this paper, we describe a technique to implement the DSC function by interlocking and integrating the AIS device and VHF. We will present the basis for achieving domestic technical standards and standardization through the linking algorithm of the data that can extract the ship information from AIS and utilize it the DSC function of VHF.

Induction Motor Drives with Low Switching Acoustic Noise Based on the Two-Phase Modulated Random Lead-Lag PWM Scheme (2상 변조된 랜덤 Lead-Lag PWM기반의 저 스위칭 소음 유도모터 구동 시스템)

  • 위석오;정영국;임영철;양승학
    • The Transactions of the Korean Institute of Power Electronics
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    • v.8 no.2
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    • pp.151-164
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    • 2003
  • In this paper, induction motor drives with low switching acoustic noise based on the 2 phase modulated RLL(Random Lead-Lag) PWM is proposed and implemented. The proposed switching method is much bettor than 3 phase modulated RLL-PWM from the standpoint of the broadening effect of the acoustic noise spectrum. Along with the randomization of PWM Pulses, SVM(Space Vector Modulation) is executed in the TMS320C31 DSP(Digital Signal Processor). To verify the validity of the proposed RPWM(Random PWM), the experimental study was tried. The experimental results show that the performance of the proposed method and the 3 phase center-aligned SVM / conventional RLL-PWM are nearly the same from the viewpoint of the constant v/f centrel. But, in case of the proposed 2 phase modulated RLL-PWM, the spectrum characteristics of the voltage and the switching acoustic noise are shown to have better broadening effect than 3 phase modulated one.

Design of a CHANCE Protocol for the ATM-Based Home Networking (ATM 기반 댁내 통신을 위한 CHANCE 프로토콜의 설계)

  • Hwang, Min-Tae;Kim, Jang-Gyeong
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.1
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    • pp.182-192
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    • 1999
  • The advance of the MPEG(Moving Picture Expert Group) and DSP(Digital Signal Processing) technologies lead the energence of the information appliances which are gradually digitalized and embedded the high-speed networking function. This paper proposes a CHANCE(Cost-effective Home ATM Network for the Consumer Electronics) protocol supporting the ATM-based high-speed networking between the information appliances within the home, and designs its specific functions including the network management and signalling function. The CHANCE protocol is basically based on the tree topology, and supports the plug-and-play function by using only the header field of the ATM cells. Unlike the existing ATM Warren protocol which uses the source routed addressing scheme to control the in-home devices from the Warren controller, the CHANCE protocol can support the inter-device controls as well as the controls from the CHANCE controller by using the switch and device identifier.

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Improvement of Dynamic Behavior of Shunt Active Power Filter Using Fuzzy Instantaneous Power Theory

  • Eskandarian, Nasser;Beromi, Yousef Alinejad;Farhangi, Shahrokh
    • Journal of Power Electronics
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    • v.14 no.6
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    • pp.1303-1313
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    • 2014
  • Dynamic behavior of the harmonic detection part of an active power filter (APF) has an essential role in filter compensation performances during transient conditions. Instantaneous power (p-q) theory is extensively used to design harmonic detectors for active filters. Large overshoot of p-q theory method deteriorates filter response at a large and rapid load change. In this study the harmonic estimation of an APF during transient conditions for balanced three-phase nonlinear loads is conducted. A novel fuzzy instantaneous power (FIP) theory is proposed to improve conventional p-q theory dynamic performances during transient conditions to adapt automatically to any random and rapid nonlinear load change. Adding fuzzy rules in p-q theory improves the decomposition of the alternating current components of active and reactive power signals and develops correct reference during rapid and random current variation. Modifying p-q theory internal high-pass filter performance using fuzzy rules without any drawback is a prospect. In the simulated system using MATLAB/SIMULINK, the shunt active filter is connected to a rapidly time-varying nonlinear load. The harmonic detection parts of the shunt active filter are developed for FIP theory-based and p-q theory-based algorithms. The harmonic detector hardware is also developed using the TMS320F28335 digital signal processor and connected to a laboratory nonlinear load. The software is developed for FIP theory-based and p-q theory-based algorithms. The simulation and experimental tests results verify the ability of the new technique in harmonic detection of rapid changing nonlinear loads.