• International Journal of Computer Science & Network Security
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• v.22 no.4
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• pp.1-12
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• 2022

In order to overcome the power fluctuation issues in photovoltaic (PV) smart grid-connected systems and the inverter nonlinearity model problem, an adaptive backstepping command-filter and a double second order generalized Integrators (DSOGI) controller are designed in order to tune the AC current and the DC-link voltage from the DC side. Firstly, we propose to present the filter mathematical model throughout the PV system, at that juncture the backstepping control law is applied in order to control it, Moreover the command filter is bounded to the controller aiming to exclude the backstepping controller differential increase. Additionally, The adaptive law uses Lyapunov stability criterion. Its task is to estimate the uncertain parameters in the smart grid-connected inverter. A DSOGI is added to stabilize the grid currents and eliminate undesirable harmonics meanwhile feeding maximum power generated from PV to the point of common coupling (PCC). Then, guaranteeing a dynamic effective response even under very unbalanced loads and/or intermittent climate changes. Finally, the simulation results will be established using MATLAB/SIMULINK proving that the presented approach can control surely the smart grid-connected system.

• The Journal of Korea Robotics Society
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• v.15 no.4
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• pp.309-315
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• 2020

This study shows a control strategy that acquires both precision and manipulation sensitivity of remote center motion with manual traction for a surgical assistant robot. Remote center motion is an essential function of a laparoscopic surgical robot. The robot has to keep the position of the insertion port in a three-dimensional space, and general laparoscopic surgery needs 4-DoF (degree-of-freedom) motions such as pan, tilt, spin, and forward/backward. The proposed robot consists of a 6-axis collaborative robot and a 2-DoF end-effector. A 6-axis collaborative robot performs the cone-shaped trajectory with pan and tilt motion of an end-effector maintaining the position of remote center. An end-effector deals with the remaining 2-DoF movement. The most intuitive way a surgeon manipulates a robot is through direct teaching. Since the accuracy of maintaining the remote center position is important, direct teaching is implemented based on position control in this study. A force/torque sensor which is attached to between robot and end-effector estimates the surgeon's intention and generates the command of motion. The predefined remote center position and the pan and tilt angles generated from direct teaching are input as a command for position control. The command generation algorithm determines the direct teaching sensitivity. Required torque for direct teaching and accuracy of remote center motion are analyzed by experiments of panning and tilting motion.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.6
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• pp.623-631
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• 2020

An electromagnetic pulse (EMP) attack on a nuclear weapon or the airlift of an electronic bomb affects weapons systems, information devices, wired and wireless communication equipment, and power supply equipment. It can lead to confusion on the battlefield. The current standards for EMP protection when applied to the military are centered on fixed and mobile facilities and equipment. It is, however, important to study EMP protection for a single tactical unit centered on the weapon system. In this study, EMP protection standards were established for command and control, maneuvering and firepower systems vulnerable to EMPs, focusing on battle tanks with mobility, firepower, and shock force. Also, specific development plans for EMP protection capabilities are proposed, including the shielding and blocking of EMPs. Through the study, the Korean government intends to ensure a unit's command and control under an EMP attack as well as preserve the viability of a unit's personnel and guarantee the conditions for the execution of a mission.

• Convergence Security Journal
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• v.20 no.5
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• pp.65-74
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• 2020

Recently, with the rapid development of eXtended Reality(XR) technology, the development and use of education and training systems using XR technology is increasing significantly. In particular, in areas that involve great risks and high costs such as military training and counter-terrorism training, the use of XR based simulators is preferred because they can improve training performance, reduce training costs, and minimize the risk of safety issues that may occur in actual training, by creating a training environment similar to actual training. In this paper, we propose a plan to build and evaluate an XR based hyper-realistic counter-terrorism education, training, and evaluation system to improve the ROK police's ability to respond to terrorist situations using the 5G and AR based Integrated Command and Control Platform previously developed by the Korea Military Academy. The proposed system is designed to improve counter-terrorism capabilities with virtual training for individual and team units based on hyper-realistic content and training scenarios. Futhermore, it can also be used as a on-site command and control post in connection with a simulation training site and an actual operation site.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.336-340
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• 1997

This paper is a study about motor technic of motion and feedforward control in order to shape cutting control on the machine tool. The shape error caused by delay of the servo system in the direction of radius at the time of circular cutting is reduced by feedforward control, shape error generated by the position command delay is minimized by using the acceleration/deceleration time constant after the interpolation. The study was verified to optimization of motion control on experiments of a vertical machining center of the machine tool.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.1068-1071
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• 1993

An algorithm of fuzzy predictive sliding control is proposed to design a jet engine control system. Sliding control using predictive scheme is adopted to compensate the time delay of fuel injector. Fuzzy rule-base is also introduced to adjust the command input for suppressing the surge. The potential of the proposed algorithm is shown through simulations utilizing a typical engine-only model.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.218-223
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• 1994

On the satellite communication system, conventional key issues of control have been focused on the attitude and orbit control, monitoring and control of communication payload such as IOT(In-Orbit-Test) and CSM(Communication System Monitoring) and so on. As the vulnerabilities are being increased on the satellite communication network, security services are required to protect it against security violated attacks. In this paper, a security architecture for satellite communication network is presented in order to provide security services and mechanisms. Authentication protocol and encryption scheme are also proposed for spacecraft command authentication and confidentiality.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.164-168
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• 1988

This paper utilizes an optimal control law for the accurate tracking servo system design. The devivation of a simple control law implementing microprocessor is made to minimize position and speed error of the controller. The 16 bit microprocessor receives command angular position and calculate the control algorithm for accurate tracking and provides control system gain scheduling to achieve very short settling time. Simulation results and some experimental results of the position controlled tracking using 4.5Kw DC servo motor are shown.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.151-156
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• 2000

The brake system is important to stop train safely. The train is sloped by regenerative brake and pneumatic brake which are continuously blended at service brake. When service is applied to train, it is controlled by train weight and brake command. The jerk limitation function is applied for impulseless smoothing braking. All brake applications in service condition have a function of the variable load control to keep the braking effort in proportion to each car load. All of control function are performed by brake controller. Therefore, we will propose the design of brake control system in order to control efficiently

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.3
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• pp.60-66
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• 2012

This paper aims to constitute a feedback vibration control system using wireless sensor networks and experiment it on a model structure to verify its effectiveness. For the purpose, we set up a feedback vibration control system composed of a wireless input/output(I/O) sensor node based on bluetooth, a home-made shear type MR damper, a shaker which generates a constant size of sine wave, and a simple beam model structure. The vibration control experiment was performed by shaking the 1/4 point of beam with a shaker. At the moment of shaking, we controled the vibration with MR damper which was placed vertically on the center of beam. Simultaneously, by acquiring acceleration response at the 2/4 point of beam, we evaluated the effectiveness of control capability. The control command was set to send a voltage signal to MR damper when the acceleration response, acquired from the wireless I/O sensor node placed at the center of beam, was more than a certain amount. Although the realtime feedback vibration control system constituted in this paper is effective only within a limited command system, it has been proven that the system was able to effectively decrease the vibration of structure by generating a control command aimed for realtime purpose. The system also showed a possibility to be used as a structural response control system adapting a variety of semi-active control algorithm.