• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.362-362
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• 2000

The purpose of this thesis is to reduce force ripple of linear pulse motor(LPM) using neural network and to enhance precision. In order to this, we propose a new controller using a neural network to compensate disturbances. The structure includes adaptation block which learns the dynamics of the periodic disturbance and forces the interferences, caused by disturbances. The proposed controller compensates an unmodeled dynamics in the LPM. The neural network changes a current command to reduce position error and force ripple of the LPM. We compare proposed controller with PI controller. Simulation result shows that the proposed controller has better performance than a PI controller without neural network.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.1
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• pp.135-142
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• 2002

Input shaping is a method for reducing residual vibration in computer controlled machines. Vibration is eliminated by convolving a sequence of impulses, an input shaper, with a desired system command to produce a shaped input. This paper shows the shape of sensitivity curve of input shaper as impulse interval T and analysis of robustness for input shaper on the z-plane. And a method is presented for designing equivalent input shaper considering sampling time $T_s$. And then we applied equivalent input shaper to crane system.

• International Journal of Precision Engineering and Manufacturing
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• v.5 no.1
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• pp.5-12
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• 2004

A human-friendly interactive system that is based on the harmonious symbiotic coexistence of human and robots is explored. Based on this interactive technology paradigm, a robotic cane is proposed for blind or visually impaired travelers to navigate safely and quickly through obstacles and other hazards faced by blind pedestrians. The proposed robotic cane, "RoJi,” consists of a long handle with a button-operated interface and a sensor head unit that is attached at the distal end of the handle. A series of sensors, mounted on the sensor head unit, detect obstacles and steer the device around them. The user feels the steering command as a very noticeable physical force through the handle and is able to follow the path of the robotic cane easily and without any conscious effort. The issues discussed include methodologies for human-robot interactions, design issues of an interactive robotic cane, and hardware requirements for efficient human-robot interactions.ions.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.277-282
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• 1996

An asymmetrical cross-coupled compensator to improve the contouring performance is proposed. This is a refinement of the structure suggested by Koren. The position loop is closed with a proportional controller as in the uncoupled system. An additional input term proportional to the component of the contour error along the corresponding axis Is included. The controller gains are chosen to give an appropriate frequency response and an optimum range for the damping ratio. The effectiveness of the proposed controller is studied by means of digital simulations of the dynamics of the drives and the controller for 3 types of command trajectories; straight line contour, cornering contour, circular contour. Substantial improvement in contouring performance is obtained for a range of contouring conditions.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.8-13
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• 2000

In this paper, a new adaptive cross-coupling control (CCC) method with an improved contour error model is proposed to maintain contouring precision in high-speed nonlinear contour machining. The proposed method utilizes variable controller gains based on the instantaneous curvature of a contour and the feedrate command. In addition, a real-time federate adaptation scheme is included in the proposed CCC to regulate cutting force. The proposed method is evaluated and compared with the conventional CCC for nonlinear contouring motion through computer simulations. The simulation results show that the proposed CCC improves the contouring accuracy and regulates cutting force more effectively than the existing method.

• Journal of the military operations research society of Korea
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• v.30 no.2
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• pp.32-49
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• 2004

The Tactical Data Link System is a standardized communication link to exchange and interface positional, situational information, command and control in real time. It has been evaluated that this Link would play an important role for tactical interoperability, situation awareness, and execution of joint operations in the future war. But considering the rapidly changing war situations, even though being admitted the necessity of the Tactical Data Link System of Army helicopter, one of superpowers in the Army, substantially we don't still have any concrete concept to build it. Therefore, this work presents how to embody the Tactical Data Link System through computer-aided system engineering on the base of Tactical Data Link System operating concept analysis of helicopters-ground units.

• Journal of the military operations research society of Korea
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• v.30 no.2
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• pp.63-80
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• 2004

This paper develops a methodology which can be used to quantify the combat effectiveness of the army C2A system by modifying C2 theory and using Air Defense Engagement Simulation. In this paper, by using Schutzer's C2 theory and Measures of Effectiveness, we modified the MOE formula he designed. Because the combat effectiveness by enhancement of C2(Command and Control) system will increase combat power of individual asset independently. In addition, we developed simulation analysis of air defense scenario by using Air Defense Engagement Simulation. The results show that modified the MOE formula is proper as compared with Air Defense Engagement Simulation method. The combat effectiveness can be obtained as a result of improved probability of detection and information accuracy through real-time information sharing and coordination by C2A system.

• Environmental and Resource Economics Review
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• v.9 no.4
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• pp.597-619
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• 2000

Marketable permit system (MPS) is a economic incentive instrument that allows polluters to achieve static and dynamic efficiency, However, Korea's atmospheric regulations are primarily based upon command and control (CAC) system and partly upon economic incentive instruments, which fail to realize its relative effectiveness, Accordingly, an introduction of MPS has been recommended with the cost effectiveness analysis in numerous studies, The literature, however, did not consider the relationship between MPS and the existing regulations, which is a key factor for the successful introduction of MPS, This paper provides a set of principles to judge how the existing regulations are reconciled with the introduction of MPS, In addition, authors execute an empirical study to show MPS's cost effectiveness when regulators apply MPS in Ulsan area for the abatement of sulfur dioxide, The results suggest that the regulations such as fuel regulation should be excluded when implementing MPS, and a flexibility in legal and regulatory system is to be required in order to secure a successful implementation of MPS.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.5219-5226
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• 2014

This paper proposes an improved scheme of pedestrian position information system using neural network theory in a GPS-disabled area. Through a learning/obtaining gait pattern and step distance about walk, run, duck walk, crab walk and crawl, the position estimation error could be minimized by rejecting the inertial navigation drift. A portable hardware module was implemented to evaluate the performance of the proposed system. The performance and effectiveness of the suggested algorithm was verified by experiments indoors.

• International Journal of Aeronautical and Space Sciences
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• v.7 no.1
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• pp.118-128
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• 2006

This paper deals with auto-landing guidance system design applicable to Smart UAV(Unmanned Aerial Vehicle). The proposed guidance law generates horizontal position, velocity and altitude commands in the longitudinal channel and heading angle command in the lateral channel to track a predetermined trajectory for automatic landing. The longitudinal guidance commands are derived from an approximated dynamic equations in vertical plane. These longitudinal guidance commands are appropriately distributed to each control input as the flight mode of Smart UAV is changed. The concept of VOR(VHF Omni-directional Range) guidance system is applied to generate the required heading angle commands to eliminate the lateral deviation from the desired trajectory. The performance of the proposed guidance system for Smart UAV is evaluated using the nonlinear simulation. Simulation results show that the proposed guidance system for auto- landing provides good tracking performance along the predetermined landing trajectory.