• Title/Summary/Keyword: Real - time

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Design Properties of Distributed Real-Time Systems (실시간 분산처리 시스템 개발을 위한 설계 방안 연구)

  • Park, Dong-Won;Ahn, Sung-Og
    • The Journal of Engineering Research
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    • v.2 no.1
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    • pp.73-82
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    • 1997
  • In this paper, we examine design trends in the development of distributed real-time system. Many real-time systems developed over the last ten years share common characteristics including use of communications, imprecise computations, the object-oriented paradigm, multiprocessor node hardware, dynamic time-driven scheduling and the inclusion of fault tolerance mechanisms. By examining the major design decisions made in previous systems, the best attributes of these systems can be coalesced together to form the "ideal" real-time system. This paper examines such a system and the advantages and disadvantages of the design decisions involved.

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A Data Structure for Real-time Volume Ray Casting (실시간 볼륨 광선 투사법을 위한 자료구조)

  • Lim, Suk-Hyun;Shin, Byeong-Seok
    • Journal of the Korea Computer Graphics Society
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    • v.11 no.1
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    • pp.40-49
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    • 2005
  • Several optimization techniques have been proposed for volume ray casting, but these cannot achieve real-time frame rates. In addition, it is difficult to apply them to some applications that require perspective projection. Recently, hardware-based methods using 3D texture mapping are being used for real-time volume rendering. Although rendering speed approaches real time, the larger volumes require more swapping of volume bricks for the limited texture memory. Also, image quality deteriorates compared with that of conventional volume ray casting. In this paper, we propose a data structure for real-time volume ray casting named PERM (Precomputed dEnsity and gRadient Map). The PERM stores interpolated density and gradient vector for quantized cells. Since the information requiring time-consuming computations is stored in the PERM, our method can ensure interactive frame rates on a consumer PC platform. Our method normally produces high-quality images because it is based on conventional volume ray casting.

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A Real Time, Internet Accessed, Monitoring System of the Ocean and Harbor Environment (인터넷을 이용한 실시간 해양항만 환경모니터링 시스템의 설계)

  • 서규우;김가야
    • Journal of Ocean Engineering and Technology
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    • v.18 no.1
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    • pp.10-15
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    • 2004
  • For effective conservation of the oceans and harbors, long-term and systematic development of the ocean and harbor monitoring system is essential. A monitoring system capable of real-time and accurate data acquisition is necessary for dealing with the level of contamination by situations, such as red tide and foods. This paper introduces an effective and economical real-time harbor environmental monitoring system that utilizes PCS wireless data communication technology. The monitoring system has various functions, such as multiple communication, TCP/IP protocol for wireless internet access, system time synchronization, and bi-directional communication between the measuring device and the server. The system has been implemented at Shinseondae harbor pier in Busan to validate the system's stability and effectiveness in data acquisition. The acquired real-time ocean and harbor environmental data is expected to have a large effect, when shared with the public through the Internet.

Design of Real Time Monitoring System of Ocean & Harbor Environment Using by Internet (인터넷을 이용한 실시간 해양항만 환경모니터링 시스템의 설계)

  • Seo, Kyu-Woo
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.05a
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    • pp.63-68
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    • 2003
  • For effective conservation of ocean and harbor, long-term and systematic development of the ocean and harbor monitoring system is essential. The monitoring system capable of real-time and accurate data acquisition is necessary for dealing with contamination such as red tide and the flood. This paper introduces the effective and economical real-time harbor environmental monitoring system that utilizes PCS wireless data communication technology. The monitoring system has various functions such as multiple communication, TCP/IP protocol for wireless internet access, system time synchronization, bi-directional communication between the measuring device and the server. The system has been implemented at Shinseondae harbor pier in Busan to validate the systems stability and effectiveness in data acquisition. The acquired real-time ocean and harbor environmental data is expected to have a large effect, when shared by public through internet.

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a Study on the Real-time Data Linkage of Field Control System for Distributed Control (분산제어를 위한 필드제어시스템의 실시간 데이터 연계)

  • Kim, S.G.;Song, S.I.;Oh, E.S.;Lee, S.W.;Gwak, K.Y.;Lee, E.W.;Park, T.R.
    • Proceedings of the KIEE Conference
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    • 2003.07b
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    • pp.777-779
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    • 2003
  • This paper describes the real-time data linkage of the field control system for distributed control in nuclear power plant environment. The most important keys of digital control system in nuclear power plant are the reliability and stability of system, and real-time control ability. This Paper brought up the hardware construction using a new method about the design of each station located upon control transmission network to improve real-time ability of field control system, and measured the station binding time between devices connected to field control module. And it was confirmed performance improvement of overall system for real-time data linkage between control devices.

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Dynamic Model of PEM Fuel Cell Using Real-time Simulation Techniques

  • Jung, Jee-Hoon;Ahmed, Shehab
    • Journal of Power Electronics
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    • v.10 no.6
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    • pp.739-748
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    • 2010
  • The increased integration of fuel cells with power electronics, critical loads, and control systems has prompted recent interest in accurate electrical terminal models of the polymer electrolyte membrane (PEM) fuel cell. Advancement in computing technologies, particularly parallel computation techniques and various real-time simulation tools have allowed the prototyping of novel apparatus to be investigated in a virtual system under a wide range of realistic conditions repeatedly, safely, and economically. This paper builds upon both advancements and provides a means of optimized model construction boosting computation speeds for a fuel cell model on a real-time simulator which can be used in a power hardware-in-the-loop (PHIL) application. Significant improvement in computation time has been achieved. The effectiveness of the proposed model developed on Opal RT's RT-Lab Matlab/Simulink based real-time engineering simulator is verified using experimental results from a Ballard Nexa fuel cell system.

Adaptive Image Transmission Scheme for Vision-Based Telerobot Control (시각기반 원격로봇 제어를 위한 적응 영상전송기법)

  • Lee, Jong-Kwang;Yoon, Ji-Sup;Kang, E-Sok
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.11
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    • pp.1637-1645
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    • 2004
  • In remote control of telerobotics equipment, the real-time visual feedback is necessary in order to facilitate real-time control. Because of the network congestion and the associated delays, the real-time image feedback is generally difficult in the public networks like internet. If the remote user is not able to receive the image feedback within a certain time, the work performance may tend to decrease, and it makes difficulties to control of the telerobotics equipment. In this paper, we propose an improved visual feedback scheme over the internet for telerobotics system. The size of a remote site image and its quality are adjusted for efficient transmission. The constructed system has a better real-time update characteristics, and shows a potential for the real-time visual control of the telerobotics system.

Design and Evaluation Method of Linux Based Soft Real-Time Kernel for Information Devices (정보기기들을 위한 리눅스 기반 연성 실시간 커널의 설계 및 평가 방법)

  • Jung, YungJoon;Lim, Donghyouk;Lim, Chaedeok;Choi, Hoon
    • IEMEK Journal of Embedded Systems and Applications
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    • v.6 no.6
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    • pp.393-400
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    • 2011
  • Recently, demands of information devices are increasing as we can find so many information devices around us such as smartphone, MID(Mobile Internet Device), Tablet. These characteristics of information devices services should support soft real-time based time guaranteed multimedia services and control internet appliances. In this situation, soft real-time supported system should be developed to consider as a total aspect of hardware, kernel, middleware, application. But this paper will describe soft real-time supporting and evaluation methods for information device as an aspect of only kernel.

A Study on the Evacuation Performance of Evacuation System using Real-time IoT Information (실시간 IoT 정보 활용 피난시스템의 피난성능 연구)

  • Lee, Chul Gyoo;Moon, Sang Ho;Lee, Sang Kyu;Lee, Gye Eun
    • Journal of Korea Multimedia Society
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    • v.22 no.2
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    • pp.281-291
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    • 2019
  • In order to reflect complex and diverse building types, resident characteristics and disaster factors, it is necessary to introduce a flexible situation-based response system based on real-time information. Intelligent CCTV, hybrid sensor, location scanner, and customized broadcasting device were examined to introduce for the real-time response intelligent response system and its feasibility was verified through field test. In addition, based on the real-time information, the evacuation simulation was executed by assuming the dormitory building and the resident of the school, and the safety of the evacuation and the shortening of the pinnacle time were confirmed. The feasibility of real time information based evacuation comparing with the existing evacuation system were verified in the case of evacuation.

SELECTIVE DETECTION OF VIABLE ENTEROCOCCUS FAECALIS USING PROPIDIUM MONOAZIDE IN COMBINATION WITH REAL-TIME PCR (Propidium monoazide와 real-time PCR을 이용한 살아있는 Enterococcus faecalis의 선택적인 검출)

  • Kim, Sin-Young;Lee, Seung-Jong;Kim, Eui-Seong;Seo, Deog-Gyu;Song, Yoon-Jung;Jung, Il-Young
    • Restorative Dentistry and Endodontics
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    • v.33 no.6
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    • pp.537-544
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    • 2008
  • Polymerase chain reaction (PCR) can detect bacteria more rapidly than conventional plate counting. However DNA-based assays cannot distinguish between viable and dead cells due to persistence of DNA after cells have lost their vitality. Recently, propidium monoazide (PMA) treatment has been introduced. The purpose of this study is to evaluate the applicability of the PMA treatment and real-time PCR method for cell counting in comparison with plate counting and to evaluate the antibacterial efficacy of 2% CHX on E. faecalis using PMA treatment in combination with real-time PCR. Firstly, to elucidate the relationship between the proportion of viable cells and the real-time PCR signals after PMA treatment, mixtures with different ratios of viable and dead cells were used. Secondly, relative difference of viable cells using PMA treatment in combination with real-time PCR was compared with CFU by plate counting. Lastly, antibacterial efficacy of 2% CHX on E. faecalis was measured using PMA treatment in combination with real-time PCR. The results were as follows : 1. Ct value increased with decreasing proportion of viable E. faecalis. 2. There was correlation between viable cells measured by real-time PCR after PMA treatment and CFU by plate counting until Optical density (OD) value remains under 1.0. However, viable cells measured by real-time PCR after PMA treatment have decreased at 1.5 of OD value while CFU kept increasing. 3. Relative difference of viable E. faecalis decreased more after longer application of 2% CHX.