• Tuberculosis and Respiratory Diseases
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• 제83권3호
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• pp.218-227
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• 2020

Background: The national Public-Private Mix (PPM) tuberculosis (TB) control project provides for the comprehensive management of TB patients at private hospitals in South Korea. Surveillance and monitoring of TB under the PPM project are essential toward achieving TB elimination goals. Methods: TB is a nationally notifiable disease in South Korea and is monitored using the surveillance system. The Korea Centers for Disease Control and Prevention quarterly generates monitoring indicators for TB management, used to evaluate activities of the PPM hospitals by the central steering committee of the national PPM TB control project. Based on the notification date, TB patients at PPM hospitals were enrolled in each quarter, forming a cohort, and followed up for at least 12 months to identify treatment outcomes. This report analyzed the dataset of cohorts the first quarter of 2016 through the fourth quarter of 2017. Results: The coverage of sputum, smear, and culture tests among the pulmonary TB cases were 92.8% and 91.5%, respectively. The percentage of positive sputum smear and culture test results were 30.7% and 61.5%, respectively. The coverage of drug susceptibility tests among the culture-confirmed cases was 92.8%. The treatment success rate among the smear-positive drug-susceptible cases was 83.2%. The coverage of latent TB infection treatment among the childhood TB contacts was significantly higher than that among the adult contacts (85.6% vs. 56.0%, p=0.001). Conclusion: This is the first official report to analyze monitoring indicators, describing the current status of the national PPM TB control project. To sustain its effect, strengthening the monitoring and evaluation systems is essential.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1539-1544
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• 1991

In this paper we formulate and solve a generalized $H^{\infty}$ control problem. The conventional formulation of $H^{\infty}$ problem has some constraints in application, e.g. it can not deal with the servo problem. This is due to the superfluous requirement of internal stability of the augmented system. In this paper, we alleviate the stability of the augmented system to admit pole-zero cancellation on the imaginary aids outside the feedback loop of G22 and K. After such generalization, the servo problem is naturally incorporated into the $H^{\infty}$ synthesis.is.

• International Journal of Control, Automation, and Systems
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• 제2권2호
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• pp.144-155
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• 2004

This paper addresses the issue of position control of a chain of multiple mass-spring-damper (CMMSD) units which can be found in many physical systems. The dynamic model of a CMMSD system with any degrees of freedom is expressed in a closed-form for the convenience of the controller design. Backstepping and model reference adaptive control (MRAC) approaches are then used to develop two adaptive output feedback controllers to control the position of a CMMSD system. The proposed controllers rely on the measurements of the input (force) and the output (position of the mass unit at the end of the chain) of the system without the knowledge of its parameters and internal states. Simulations are used to verify the effectiveness of the controllers

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
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• pp.526-529
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• 1998

In this paper, we proposed a nonlinear sliding mode controller to regulate the swinging angle of Overhead Crane System. Roughly speaking, the controller is designed to regulate an output(the swing angle) while providing internal stability. It is difficult to apply many of standard nonlinear control design techniques. In contrast to control that use a command generator and possibly a time-varying feedback, our control law is simple autonomous nonlinear controller. We analyze the stability of the closed-loop system using an $L_2$ Sliding surface conditions approach on a nonlinear feedback linearization of the system about the desired periodic orbit. One can easily extend this approach to analyze the robustness of the control system with respect to disturbances and parameter variations.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3074-3079
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• 2007

The conventional control valves have been used at the locations occurring high differential pressure and high temperature which causes cavitation, flashing, severe vibration due to abrupt flow change, and sudden pressure drop. Previous studies concerning control valves focused to prevent damage of valve trim due to the internal leak and low flow rate. The newly designed helical trim of control valve has been installed at the location of high pressure change and high temperature in a power plant, and operated for evaluation. It is confirmed that the new control valve developed in this study generates flow characteristics in comparison with previous helical trim of control valves.

• 대한전자공학회논문지
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• 제25권8호
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• pp.906-915
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• 1988

The reliability enhancement is the critical issue in many computer applications, particulary in process control system. In this paper we describe how to achieve the reliability improvement in control system which is based on multiprocessors. The proposed method is accomplished by using the techniques of fault detection which composed by internal and external fault detections, fault isolation for removing the fault propagation, safety action for driving safe input, and fault diagnosis. This approach is experimented and asopted in boiler backup control system constructed by VMEbus system, CPU boards, graphic system, and other interface boards with UNIX operating system.

• 한국자동차공학회논문집
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• 제19권2호
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• pp.26-34
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• 2011

Hybrid powertrain systems have been developed to improve the fuel efficiency of internal combustion engines. In the case of a parallel hybrid powertrain system, an engine and a motor are directly coupled. Because of the hardware configuration of the parallel hybrid system, friction and the pumping losses of internal combustion engines always exists. Such losses are the primary factors that result in the deterioration of fuel efficiency in the parallel-type hybrid powertrain system. In particular, the engine operates as a power consumption device during the fuel-cut condition. In order to improve the fuel efficiency for the parallel-type hybrid system, cylinder deactivation (CDA) technology was developed. Cylinder deactivation technology can improve fuel efficiency by reducing pumping losses during the fuel-cut driving condition. In a CDA engine, there are two operating modes: a CDA mode and an SI mode according to the vehicle operating condition. However, during the mode change from CDA to SI, a serious fluctuation of the air-fuel ratio can occur without adequate control. In this study, an air-fuel ratio control algorithm during the mode transition from CDA to SI was proposed. The control algorithm was developed based on the mean value CDA engine model. Finally, the performance of the control algorithm was validated by various engine experiments.

• 정보보호학회논문지
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• 제21권4호
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• pp.101-114
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• 2011

산업스파이 및 악의적인 내부 이용자에 의한 기업 내부 핵심 정보유출 사건이 증대되고 있는 현실을 반영하듯, 감사 및 로그 보안기술의 중요성이 한층 부각되고 있는 것이 현실이다. 본 논문에서는 기업의 중요 정보를 처리하는 운영체제에 접속한 사용자에 대한 행위를 면밀히 감시 및 분석하여, SOX 법안에서 요구하는 수준의 기업 내부통제를 위한 세션로깅시스템을 제안한다. 본 논문에서 제안하는 시스템은 운영체제에 접속한 사용자의 불법적인 행위를 모니터링하고, 그 행위 과정의 세부 로그를 통해 명확한 증거를 제시할 수 있도록 하고 있다. 이를 위해 논문에서 제안한 별도의 여러 서비스를 추가하여 운영체제를 변경하는데, 이러한 서비스는 기존의 운영체제가 제공하는 인터페이스를 이용하면서 접근을 제어하고 로그를 획득하기 위한 기능을 추가적으로 제공한다. 서버에 접속한 관리자 및 사용자의 행위에 대한 세션 로그를 중앙 집중적으로 저장, 관리하고 해당 로그에 대한 검색 및 조회 기능을 제공할 수 있도록 하여, SOX 법안에서 요구하는 수준의 기업 내부통제를 위한 컴퓨터 포렌식 시스템 및 로그 기술을 제안한다.

• Nuclear Engineering and Technology
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• 제52권7호
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• pp.1443-1451
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• 2020

The objective of this study is to design a robust power control system for a small pressurized water reactor (PWR) to achieve stable power operations under conditions of external disturbances and internal model uncertainties. For this purpose, the multiple-input multiple-output transfer function models of the reactor core at five power levels are derived from point reactor kinetics equations and the Mann's thermodynamic model. Using the transfer function models, five local reactor power controllers are designed using an H infinity (H_∞) mixed sensitivity method to minimize the core power disturbance under various uncertainties at the five power levels, respectively. Then a multimodel approach with triangular membership functions is employed to integrate the five local controllers into a multimodel robust control system that is applicable for the entire power range. The performance of the robust power system is assessed against 10% of full power (FP) step load increase transients with coolant inlet temperature disturbances at different power levels and large-scope, rapid ramp load change transient. The simulation results show that the robust control system could maintain satisfactory control performance and good robustness of the reactor under external disturbances and internal model uncertainties, demonstrating the effective of the robust power control design.

• 대한한방내과학회지
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• 제29권3호
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• pp.543-553
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• 2008

Objective: The goal of this study was to determine the anti-asthma mechanism of SF on TNF-${\alpha}$ induced activation on A549 (human type II-like epithelial) cells. Using oligonucleotide microarray, we sought to establish the molecular mechanism of the protective effects of SF on A549 cells. Material & Methods : Cells were cultured in three different conditions: 1) negative control group was cultured in normal condition of DMEM, 2) positive control group was activated with TNF-${\alpha}$, IL-4. and IL-1${\beta}$, and 3) SF treated group was previously treated with 0.1${\mu}g/ml$ SF after TNF-${\alpha}$, IL-4. and IL-1 activation. Cells of positive control and SF treated groups were cultured for 30 min, 1hr, 3hr and 6hr. Results : The comparative analysis of the gene expression profile revealed that proinflammatory cytokines such as IL1F8, IL1F9, IL1R1. IL1RN, IL1RAPL1, IL8, TNFRSF4, TNFSF10c, TNFSF13, TRAF5, and TRAF7 and inflammation-related genes including MMP2, MMP11, MMP14, MMP15, MMP16, MMP19, MMP25, and MMP27 were down regulated with SF treatment. Cell adhesion molecule genes such as ITGB1, ITGBL1, selectin P ligand, selectin E, ICAM2, ICAM3, VCAM1, PECAM, FCER1G and MMP28 genes were also down-regulated in SF treated A549 cells. Conclusion : These results suggest that the anti-asthmatic effects of SF could be mediated by regulating specific genes related with cell adhesion, proinflammatory cytokine and inflammation-related genes in A549 cells.