• Title/Summary/Keyword: Central control system

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A Functional Design of Programmable Logic Controller Based on Parallel Architecture (병렬 구조에 의한 가변 논리제어장치의 기능적 설계)

  • 이정훈;신현식
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.40 no.8
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    • pp.836-844
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    • 1991
  • PLC(programmable logic controller) system is widely used for the control of factory. PLC system receives ladder diagram which is drawn by the user to implement hardware logic, converts the ladder diagram into sequence program which is executable in the PLC system, and executes the sequence program indefinitely unless user breaks. The sequence program processes the data of on/off signal, and endures 1 scan delay and missing of pulse-type signal shorter than a scan time. So, data dependency doesn't exist. By applying theis characteristics to multiprocessor architecture, we design parellel PLC functionally and evaluate performance upgrade. Parallel PLC consists of central processing module, N general processing unit, and a shared memory by master-slave type. Each module executes allocated sequence program by the control of central processing module. We can expect performance upgrade by parallel processing, and reliability by relocation of sequence program when error occurs in processing module.

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Development of On-line Control System Using RFID On the Prison (RFID를 이용한 교도소의 온라인 통제 시스템 개발)

  • Park, Seung-Hwan;Ku, Ja-Yl
    • 전자공학회논문지 IE
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    • v.45 no.4
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    • pp.74-79
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    • 2008
  • The paper represented central management system of dual direction that does opening and shutting, real-time check of various doors of the prison in the on-line network. To remove a fault of 125kHz RFID technology, we use 13.56MHz RFID technology, can solve the problem of the maintenance and trust, development of on-line control and management system that ring the alarm in the abnormal opening and shutting doors.

Effect of Imperfect Power Control on Performance of a PN Code Tracking Loop for a DS/CDMA System

  • Kim, Jin-Young
    • Proceedings of the IEEK Conference
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    • 2000.06a
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    • pp.209-212
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    • 2000
  • In this paper, effect of imperfect power control on performance of a pseudonoise (PN) code tracking loop is analyzed and simulated for a direct-sequence/code-division multiple access (DS/CDMA) system. The multipath fading channel is modeled as a two-ray Rayleigh fading model. Power control error is modeled as a log-normally distributed random variable. The tracking performance of DLL (delay-locked-loop) is evaluated in terms of tracking jitter and mean-time-to-lose-lock (MTLL). From the simulation results, it is shown that the PN tracking performance is very sensitive to the power control error.

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A Study on the development of automatic control programming for projection machine (사출기의 자동제어 프로그램 개발에 관한 연구)

  • 김현기;홍용인;이천희
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.1145-1148
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    • 1999
  • In this paper we developed the communication protocol in which can transmitter receive a data and instruction in pressure and control computer. This system can dramatically increase production by maximize by control the error in central unit and monitoring. When developed these pressure automatic control system, it can be automation product in factory and decrease man-power.

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Summative Usability Assessment of Software for Ventilator Central Monitoring System (인공호흡기 중앙감시시스템 소프트웨어의 사용적합성 총괄평가)

  • Ji-Yong Chung;You Rim Kim;Wonseuk Jang
    • Journal of Biomedical Engineering Research
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    • v.44 no.6
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    • pp.363-376
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    • 2023
  • According to the COVID-19, development of various medical software based on IoT(Internet of Things) was accelerated. Especially, interest in a central software system that can remotely monitor and control ventilators is increasing to solve problems related to the continuous increase in severe COVID-19 patients. Since medical device software is closely related to human life, this study aims to develop central monitoring system that can remotely monitor and control multiple ventilators in compliance with medical device software development standards and to verify performance of system. In addition, to ensure the safety and reliability of this central monitoring system, this study also specifies risk management requirements that can identify hazardous situations and evaluate potential hazards and confirms the implementation of cybersecurity to protect against potential cyber threats, which can have serious consequences for patient safety. As a result, we obtained medical device software manufacturing certificates from MFDS(Ministry of Food and Drug Safety) through technical documents about performance verification, risk management and cybersecurity application.The purpose of this study is to conduct a usability assessment to ensure that ergonomic design has been applied so that the ventilator central monitoring system can improve user satisfaction, efficiency, and safety. The rapid spread of COVID-19, which began in 2019, caused significant damage global medical system. In this situation, the need for a system to monitor multiple patients with ventilators was highlighted as a solution for various problems. Since medical device software is closely related to human life, ensuring their safety and satisfaction is important before their actual deployment in the field. In this study, a total of 21 participants consisting of respiratory staffs conducted usability test according to the use scenarios in the simulated use environment. Nine use scenarios were conducted to derive an average task success rate and opinions on user interface were collected through five-point Likert scale satisfaction evaluation and questionnaire. Participants conducted a total of nine use scenario tasks with an average success rate of 93% and five-point Likert scale satisfaction survey showed a high satisfaction result of 4.7 points on average. Users evaluated that the device would be useful for effectively managing multiple patients with ventilators. However, improvements are required for interfaces associated with task that do not exceed the threshold for task success rate. In addition, even medical devices with sufficient safety and efficiency cannot guarantee absolute safety, so it is suggested to continuously evaluate user feedback even after introducing them to the actual site.

The Effects of Ginseng on Central Nervous System (인삼(人蔘)의 중추신경(中樞神經)에 대(對)한 작용(作用))

  • Lee, S.W.
    • The Korean Journal of Pharmacology
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    • v.10 no.2
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    • pp.13-23
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    • 1974
  • Results of an experiment on the general behavior of rats in order to explore the possible pharmacological actions of Panax Ginseng upon the central nervous system can be summarized as follows: 1) The rats treated with Ginseng-saponin intraperitoneally with the doses of 50 or 100 mg/kg show the decreased sleeping component and increase in lying and grooming component and walking and rearing component of general behavior. 2) There are no difference between control group and saline treated group in pattern of general behavior components. 3) In the Ginseng-saponin treated groups, the amphetamine stimulated walking and rearing component of genenarl behavior are reduced but lying and grooming component are elevated. 4) Ginseng-saponin shows very low acute toxicity in mice. The $LD_{50}$ in mice of 24 hours after intraperitoneal injection was 795 mg/kg. From the above findings, it is to suggest that the Ginseng saponin might stimulate the central nervous system but its mode of action appears to be different from that of amphetamine. And the effects of Ginseng saponin may be varied depending on various experimental situation or condition of animals.

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Health Promoting Effects of Lactoferrin from Milk

  • Shimizu, Hirohiko;Ando, Kunio;Hoshino, Tatsuo
    • Journal of Dairy Science and Biotechnology
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    • v.24 no.2
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    • pp.21-24
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    • 2006
  • The ubiquitous presence of lactoferrin(LF) receptor in human as reported by the research group of Prof. Bo Lonnerdal, Univ. California (Suzuki, Y. A.,2001) encouraged us to search for the unknown physiological roles of Lf. Under the collaboration with Prof. Etsumori Harada, Tottori Univ., and his research group, we have found two novel biological activities of LF as the control of the lipid metabolism and the effect on the central nervous system. Relating to the lipid metabolism, LF could, in animal experiments, reduce triglyceride and total cholesterol both in blood and liver (Takeuchi, T et αl., 2003). LF increased plasms HDL-C and lowered LDL-C. In the central nervous system, LF showed anti-nociceptive activity mediated by ${\mu}$-opioid receptor in the rat spinal cord (Hayashida, K. et al., 2003). LF enhanced analgesic action of morphine synergistically via nitric oxide synthesis (Hayashida, K., et al., 2003) LF showed opioid-mediated suppressive effect on distress induced by maternal separation in rat pups (Takeuchi, T., et al., 2003).

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A Study on the Integration Control System Development for Smoke Control (연기제어를 위한 통합제어시스템 개발에 관한 연구)

  • Lee, Dong-Myung
    • Journal of the Korean Society of Hazard Mitigation
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    • v.6 no.4 s.23
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    • pp.15-20
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    • 2006
  • This study developed integration control system that improve efficiency and give flexibility of smoke control system and can improve prevention of disasters performance. The reliable each kind sensor and of integration control system was developed by establishing the specifications, algorithms and constructing engineering data. More correct and reliable control function of optimization can be obtained by the central control from integration control system rather than the existent individual control. This sees to do to impose flexibility to smoke control system. Also, this will provide the basics of integration control system and ability security of smoke control system and can construct smoke control system of performance based.

Design of Robust $H_\infty$ Control for Interconnected Systems: A Homotopy Method

  • Chen Ning;Ikeda Masao;Gui Weihua
    • International Journal of Control, Automation, and Systems
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    • v.3 no.2
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    • pp.143-151
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    • 2005
  • This paper considers a robust decentralized $H_\infty$ control problem for uncertain large-scale interconnected systems. The uncertainties are assumed to be time-invariant, norm-bounded, and exist in subsystems. A design method based on the bounded real lemma is developed for a dynamic output feedback controller, which is reduced to a feasibility problem for a nonlinear matrix inequality (NMI). It is proposed to solve the NMI iteratively by the idea of homotopy, where some of the variables are fixed alternately on each iteration to reduce the NMI to a linear matrix inequality (LMI). A decentralized controller for the nominal system is computed first by imposing structural constraints on the coefficient matrices gradually. Then, the decentralized controller is modified again gradually to cope with the uncertainties. A given example shows the efficiency of this method.