• 제목/요약/키워드: case control

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Evaluation of a Tuberculosis Control Program at Community Health Centers (보건소 결핵관리사업 평가)

  • Hwang, Eun-Jeong
    • Journal of Korean Public Health Nursing
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    • v.21 no.2
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    • pp.241-251
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    • 2007
  • Purpose: To identify the effects on tuberculosis mortality of a tuberculosis control program conducted at 108 community health centers in terms of structure and process. Methods: The dependent variable was tuberculosis mortality, and the independent variables were the structure(type of centers, staff, nurses, doctors, budget) and process(chest X-ray checking, immunization, case detection, health education, patients registering & managing) of the tuberculosis control programs at the community health centers. Data were analyzed using descriptive analysis and stepwise regression analysis. Result: Tuberculosis morality was positively correlated with type of centers(rural area)(p<0.01), but negatively correlated with type of centers(large cities) (p<0.01), (middle cities)(p<0.05), staff FTE(p<0.05), and number of nurses(p<0.05). Regression analysis indicated that type of centers(rural area)($\beta$=0.457) and case detection($\beta$=0.234) had a significant effect on tuberculosis mortality. Conclusion: Ultimately, this study will provide information to improve the effectiveness of tuberculosis control programs in community health centers.

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Optimal iterative learning control with model uncertainty

  • Le, Dang Khanh;Nam, Taek-Kun
    • Journal of Advanced Marine Engineering and Technology
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    • v.37 no.7
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    • pp.743-751
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    • 2013
  • In this paper, an approach to deal with model uncertainty using norm-optimal iterative learning control (ILC) is mentioned. Model uncertainty generally degrades the convergence and performance of conventional learning algorithms. To deal with model uncertainty, a worst-case norm-optimal ILC is introduced. The problem is then reformulated as a convex minimization problem, which can be solved efficiently to generate the control signal. The paper also investigates the relationship between the proposed approach and conventional norm-optimal ILC; where it is found that the suggested design method is equivalent to conventional norm-optimal ILC with trial-varying parameters. Finally, simulation results of the presented technique are given.

Modularization Design of On-board Train control Software for EMU using MATLAB (MATLAB을 이용한 전동차용 저어 S/W 모듈화 설계 연구)

  • Han, Seong-Ho;Lee, Su-Gil;Kim, Su-Gon;Ahn, Tae-Ki;Lee, Woo-Dong
    • Proceedings of the KIEE Conference
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    • 2001.07b
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    • pp.1220-1222
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    • 2001
  • We proposed a modularization design technique for implementing software of on-board train control system. We already proved the efficiency of CASE Tool(SCADE) for safety critical software design. The several functions of train are implemented on CASE tool each modules. We divided functions of train into modules based on the modularization design. We used MATLAB for design of on-board train control software. We proved that this technique is more useful for the software design of on-board train control for EMU.

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Analysis of a Communication Network for Control Systems in Nuclear Power Plants and a Case Study (원자력 발전소 제어 계통을 위한 통신망의 해석과 사례 연구)

  • Lee, S.W.;Yoon, M.H.;Moon, H.J.;Shin, C.H.;Lee, B.Y.
    • Proceedings of the KIEE Conference
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    • 1999.07b
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    • pp.1013-1016
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    • 1999
  • In this paper, a real-time communication method using a PICNET-NP(Plant Instrumentation and Control Network for Nuclear Power plant) is proposed with an analysis of the control network requirements of DCS (Distributed Control System) in nuclear power plants. The method satisfies deadline in case of worst data traffics by considering aperiodic and periodic real-time data and others. In addition, the method was used to analyze the data characteristics of the DCS in existing nuclear power plant. The result shows that use of this method meets the response time requirement(100ms)

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Extensions of the solution region for a discrete algebraic riccati equation and its application to$H_{\infty}$ controller design (이산 대수 Rccati방정식의 해의 존재 영역 확장 및 $H_{\infty}$베어기 설계 응용)

  • 권욱현;박부견;김상우
    • 제어로봇시스템학회:학술대회논문집
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    • 1989.10a
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    • pp.461-466
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    • 1989
  • This paper describes some properties of a discrete algebraic Riccati equation and its application to $H^{\infty}$ control design. The conditions, under which an input weighting matrix can be found for a negative output weighting matrix in order that a solution P for a discrete algebraic equation may exist, are suggested in case of a stable A. This result is applied to a $H^{\infty}$ controller design for the special case of nonsingular B. It is based on a state feedback control law whose objective is to reduce the effect of input disterbances below a prespecified level. This law requires the solution of a modified algebraic Riccati equation, which provides an method for the $H^{\infty}$ optimization control problem approximately.ly.

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A Quantization Algorithm without Accumulative Error

  • Koh, Kyoung-Chul;Cho, Hyun-Suck
    • 제어로봇시스템학회:학술대회논문집
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    • 1999.10a
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    • pp.313-316
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    • 1999
  • In this paper, a quantization algorithm by which the accumulative error can be prevented is presented. In digital control systems, the quantization cannot be avoided because of the finite word length of digital computers. The error due to quantization of the computed values may be tolerable in case of directly using them. In case of using the accumulated values, the error between sum of the original values and that of the quantized values becomes larger as the number of the values to be summed increases. Such an increasing accumulative error is critical for the control of precise NC machines, robots and autonomous vehicles. To solve this problem, a quantization algorithm without the accumulative error is presented. Basically, the algorithm is based on the feedback loop by which the accumulationive of the quantization error can be prevented. The error boundness of the proposed algorithm is proven and a computer simulation is performed to show the validity of the algorithm.

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Study of New Control Method for Linear Periodic System

  • Jo, Janghyen
    • 제어로봇시스템학회:학술대회논문집
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    • 1999.10a
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    • pp.83-87
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    • 1999
  • The purpose of this study is to provide the new method for selection of a close to optimal scalar control of linear time-periodic system. The case of scalar control is considered, the gain matrix being assumed to be at worst periodic with the system period T. The form of gain matrix may have various kinds but must have same period, for example, one of each element being represented by Fourier series. As the optimal gain matrix I consider the matrix ensuring the minimum value of the larger real part of the Poincare exponents of the system. Finally we present a pole placement algorithm to make the given system be stable. It is possible to determine the stability of the given periodic system without get the analytic solution. The application of the method does not require the construction of the Floquet solution. At present state of determination of the gain matrix for this case will be done only by systematic numerical search procedures.

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A Study on the Pressure Difference of Smoke Control Influence Factor in the Super High-rise Building (초고층 건물의 제연영향요소에 따른 수직피난공간 압력분포 시뮬레이션)

  • Choi, Seung-Hyuck;Lee, Dong-Yun;Jun, Hyun-Do;Lee, Dong-Yun
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.130-135
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    • 2009
  • These days, the super high-rise buildings construction plans are increased in Korea. But the stack effect in the super high-rise building interrupts the smoke control system's operation because of pressure difference, so it is more dangerous than the general building when firing. Therefore it needs to study about the pressure difference in the super high-rise buildings. We research the smoke control influence factor in the super high-rise building. Reflecting the influence factor, the simulation is practiced the case by case.

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SOLVING A SYSTEM OF THE NONLINEAR EQUATIONS BY ITERATIVE DYNAMIC PROGRAMMING

  • Effati, S.;Roohparvar, H.
    • Journal of applied mathematics & informatics
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    • v.24 no.1_2
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    • pp.399-409
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    • 2007
  • In this paper we use iterative dynamic programming in the discrete case to solve a wide range of the nonlinear equations systems. First, by defining an error function, we transform the problem to an optimal control problem in discrete case. In using iterative dynamic programming to solve optimal control problems up to now, we have broken up the problem into a number of stages and assumed that the performance index could always be expressed explicitly in terms of the state variables at the last stage. This provided a scheme where we could proceed backwards in a systematic way, carrying out optimization at each stage. Suppose that the performance index can not be expressed in terms of the variables at the last stage only. In other words, suppose the performance index is also a function of controls and variables at the other stages. Then we have a nonseparable optimal control problem. Furthermore, we obtain the path from the initial point up to the approximate solution.

Speed-Sensorless Control of DC Servo Motor Using a High Gain Observer (고이득 관측기를 이용한 센서없는 직류서보전동기의 속도 제어)

  • 김상훈;김낙교
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.52 no.10
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    • pp.583-590
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    • 2003
  • This paper deals with speed control of DC servo motor using a high gain obserber. It was designed to estimate rotor speed of DC servo motor and it carries out speed control from the feedback of the estimated speed signal. Also, PI controller was used in speed controller. In order to verify the performance of the high gain observer which is proposed in this paper, it is compared estimate performance of Luenberger Observer and High Gain Observer with the computer simulation. Effectiveness of the proposed high gain observer is proved from the experiment to compare the case with a speed sensor to the case with high gain observer in the speed control of DC servo motor.