• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.4
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• pp.351-357
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• 1999

This paper proposes the coordinated control of SVC and UTLC at the distribution substation to get larger operating margin of SVC for the voltage stability control by reactive power compensation. In the conventional method, ULTC doesn't respond to the variation of source voltage, so SVC has the entire responsibility for it. It could cause the lack of operating margin of SVC in some condition. It, however, is important to secure an operating margin for the dynamic stability control in emergancy. This paper proposes the coordinated control method that SVC controls the supply voltage and ULTC respond to the SVC compensation valve based on the relation between SVC compensation and ULTC tap position. The numerical simulation verifies that the proposed system could increase the operating margin of SVC compared with the conventional system.

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.227-230
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• 2004

The regulator that was designed for space use must be operating on the severe circumstance. For example, operating temperature is below 90K and operating pressure is 20.7 MPa. The design of regulator for liquid propulsion system was accomplished and dynamic characteristic was analyzed successfully.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.5
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• pp.789-797
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• 2003

In the procedure of the hydraulic control system design, a linearized approximate equation described by the first order terms of Taylor series has been widely used. Such a linearized equation is effective just near the operating point, However, pressure and flowrate in actual hydraulic systems are usually not confined near an operating point. This study suggests a new linearized flow equation for a servovalve as a modified form of the conventional linearized flow equation. Subsequently, a procedure to determine effective operating point for the new linearized equation is proposed. From the evaluations of time responses and frequency responses obtained from simulations for a hydraulic control system, the effectiveness of the new linearized equation and the procedure to determine effective operating point is confirmed.

• Journal of the Ergonomics Society of Korea
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• v.8 no.1
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• pp.41-46
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• 1989

The purpose of this study is to improve robot motion control in teaching and operating the expert system/world coordinate system (TOES/WCS) constructed in the previous study. The major contribution of this study is reduction of the inaccuracy in coordinated reading and the movement time of robots in macro motion control. This study also reduces undesirable time of micro motion control by using an unit control (UC) and a micro unit control (MUC) in micro motion control.

• The KIPS Transactions:PartD
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• v.10D no.5
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• pp.773-780
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• 2003

SecuROS(Secure & Reliable Operating System) prevents and blocks possible system cracking by implementing additional security functions in FreeBSD 4.3 operating system (OS) kernel, including access control, user authentication, audit trail, encryption file system and trusted channel. This paper describes access control technique, which is one of core technologies of SecuROS, introduces the implementations of DAC, MAC and RBAC, all of which are corresponding access control policies, and show security and results of performance measurement on the basis of application of access control policies. Finally, security and performance between conventional OS environment and environment adopting access control policy is described.

• Journal of Mechanical Science and Technology
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• v.14 no.4
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• pp.393-400
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• 2000

In this paper, a new algorithm for noninteracting control system design is proposed and applied to ship propulsion system control. For example, if a ship diesel engine is operated by consolidated control with controllable pitch propeller (CPP), the minimum fuel consumption is achieved satisfying the demanded ship speed. For this, it is necessary that the ship is operated on the ideal operating line which satisfies the minimum fuel consumption, and the both pitch angle of CPP and throttle valve angle are controlled simultaneously. In this context of view, this paper gives a controller design method for a ship propulsion system with CPP based on noninteracting control theory. Where, linear matrix inequality (LMI) approach is introduced for the control system design to satisfy the given $H_{\infty}$, constraint in the presence of physical parameter perturbation and disturbance input. To the end, the validity and applicability of this approach are illustrated by the simulation in the all operating ranges.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.7
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• pp.587-595
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• 2006

A system operating algorithm was developed for the effective operation of a multi-type air-conditioning system. The system operating algorithm includes control algorithms for a safety mode, an initial operating mode, a stabilization mode, a fault diagnosis mode, an efficiency mode, and a tracking mode. Various tests were performed to show the effectiveness of these algorithms. Tests showed good results for the operation of a multi-type air-conditioning system. Therefore, these algorithms developed for this study may be used for the effective control of a multi-type air-conditioning system.

• International Journal of Aerospace System Engineering
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• v.1 no.1
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• pp.10-15
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• 2014

This study presents technical description of the operating program development that operates the test bench for functional test of EECU. The test bench is capable of testing, simulation and adjustment of the EECU software using the operating program. The test bench is for the Development Project of the EECU platform for FADEC system. The operating program is consists of 3 modules which are the test bench operating module, cockpit simulator module and SILS module. The operating module mainly carries out the EECU test with manual operation and operating scenarios. Also that record and process the test data. The cockpit simulator module is capable of implementation of virtual cockpit control input and engine status display. The SILS module can simulate engine and EECU operation in software environment.

• Journal of the Semiconductor & Display Technology
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• v.16 no.3
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• pp.25-30
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• 2017

Arago's disk system consists of a speed controller of the DC motor (inner loop controller) and a position controller of the magnetic bar angle (main controller), which are implemented by the design of the PI and PID controller, respectively. First, we analyzed the nonlinear characteristics of the Arago disk system and found the operating point range of three locations as a result. In this paper, a gain scheduler method was applied to guarantee a constant control performance in the range of $0{\sim}130^{\circ}C$, and a structure to change the controller according to the control reference value based on the previously obtained operating points was experimentally implemented. The Distributed Control Systems (DCS) configuration using the Controller Area Network (CAN) was used to verify the proposed method by improving the operational efficiency of the entire experimental system. So, simplicity of the circuit and easy diagnosis were achieved through a single CAN bus communication.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1655-1658
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• 2004

In this paper, we design and implement remote servo motor control system with real-time micro embedded operating system. The system, where controller and camera image grabber are mounted, handles control commands transmitted from a remote PC web browser. A hard real-time servo motor driver running on the real-time micro embedded OS and then a digital control application which confirms precise sampling time intervals is constructed. Frame grabber images transmitted from camera are saved in a image data format to view on remote PC web browser.