• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.389-394
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• 2004

A Fuzzy Logic Sliding Mode Control or FLSMC for the uninterruptible power system (UPS) is presented, which is tracking a sinusoidal ac voltage with specified frequency and amplitude. The FLSMC algorithm combines feedforward strategy with the Variable Structure Control (VSC) or Sliding Mode Control (SMC) and fuzzy logic control. The control function is derived to guarantee the existence of a sliding mode. FLSMC has an advantage that the stability of FLSMC can be proved easily in terms of VSC. Furthermore, the rules of the proposed FLSMC are independent of the number of system state variables because the input of the suggested controller is fuzzy quantity sliding surface value. Hence the rules of the proposed FLSMC can be reduced. The simulation results illustrate that the purposed approach gives a significant improvement on the tracking performances. It has the small overshoot in the transient and the smaller chattering in the steady state than the conventional VSC. Moreover, its can achieve the requirements of robustness and can supply a high-quality voltage power source in the presence of plant parameter variations, external load disturbances and nonlinear dynamic interactions.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.3
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• pp.645-650
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• 2010

In this paper we present the Bimodal-tram simulator using the PXI embedded real-time controllers. The Bimodal-tram is developed in KRRI (Korea Railroad Research Institute). The vehicle can be automatically operated by navigation control system (NCS). For the automatic driving, the vehicle lanes will be marked with permanent magnets that are placed in the ground. The vehicle is controlled by NCS. NCS governs the manual mode and automatic mode driving. The simulator is designed by an identical conception with the real control condition. The dynamic motion of vehicle is simulated by the nonlinear dynamic model. The control computer calculates the control values. The signal interface is linked by CAN communication. The simulation is processed by real-time base. The test driver can see the graphic motion of vehicle and can operate the steering wheel, gas and brake pedal to control direction and velocity of vehicle during the simulation. At present, the simulator is only operated by manual mode. The automatic mode will be linked after the control algorithm is finished. We will use the simulator to develop the control algorithm in the automatic mode. This paper shows the simulator designed for Bimodal-tram using real-time based controller. The results of the test using the simulator are presented and discussed.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.23 no.1
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• pp.49-55
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• 2015

This paper deals with dynamic modeling and controller design of a future Korean lunar module planned to be launched 2020's in Korea. For dynamic modeling of the lunar module, we first assume the lunar module as a rigid body. And we derive equations of motion for the lunar module by considering allocation of main thrusters and reaction thrusters. With the equation of motion, we design the controller based on the quaternion. A Pulse Width Pulse Frequency modulator(PWPFM) is selected for generating on/off signal. Finally, we construct a 2-phase descent mode including initial guidance mode, terminal guidance mode. The MATLAB simulation is performed for evaluating the descent ability and final landing velocity. The dynamic modeling and descent simulation of the lunar module in this paper could be applied for developing the future work of the Korean lunar exploration program.

• Journal of Satellite, Information and Communications
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• v.8 no.3
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• pp.10-14
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• 2013

In this paper, when applying current-mode circuit design technique showing constant power dissipation none the less operation frequency, to the low power design of dynamic voltage frequency scaling, we introduce the low power current-mode circuit design technique applying MOSFET in sub-threshold region, in order to solve the problem that has large power dissipation especially on the condition of low operating frequency. BSIM 3, was used as a MOSFET model in circuit simulation. From the simulation result, the power dissipation of the current memory circuit with sub-threshold MOSFET showed $18.98{\mu}W$, which means the consumption reduction effect of 98%, compared with $900{\mu}W$ in that with strong inversion. It is confirmed that the proposed circuit design technique will be available in DVFS using a current-mode circuit design.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.4
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• pp.307-313
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• 2009

Quantitative analysis of optical scattering intensities from a Au nanoparticle with a diameter of 100 nm, which is effected by the localized surface plasmon resonance (LSPR), were numerically carried out by using a dark-field detection scheme on prism basal plane for two different beam incident modes of reflectance (R-mode) and transmittance (T-mode). Two-dimensional finite difference time domain (FDTD) algorithm was adopted, and its applicabilibility was verified by comparing the simulation results with the theoretical ones. Simulation results of the scattered light intensities from a Au nanoparticle revealed that the scattered intensity of the T-mode was much stronger than that of R-mode. Comparison of the calculated results with the theoretical intensity distribution on the prism showed that the scattered intensity is marimized when the evanescent field, which is generated from the interface of prism and air at TIR angle, is coupled with Au nanoparticle.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.7
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• pp.292-297
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• 2002

In this paper, a flat-type $L_{-}$-$B_{8}$ mode Ultrasonic Motor[USM] having the size of 80 x 20 x ${1.5}mm^3$($l{\times}\omega{\times}t$) was designed and fabricated to examine the characteristics of an ultrasonic vibration. We used ANSYS simulation program based on FEM to get the optimum design of this USM. As results of experiment, the fastest speed of revolution(v), the maximum torque(T) and the efficiency(n) were 37.5cm/s, 5.0 mN.m and 1.17% when 27.9KHz, 150N, 50V were applied respectively. And this flat-type $L_{-}$-$B_{8}$ mode USM could be controlled the speed of rotor revolution by applied voltage, frequency and pre-load of rotor as well as showed the characteristics of typical drooping torque-speed, large torque and high speed. So, we think that this flat-type $L_{-}$-$B_{8}$ mode USM has characteristics of enough torque and velocity to be usable for applications in forwarding device of an electric card or a paper, etc.

• Proceedings of the KIEE Conference
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• 1998.07f
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• pp.2036-2038
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• 1998

In the buck-boost DC-DC chopper which is used at a certain situation such as in factories where loads often change a lot, the switches in the device make big energy loss in operating at Buck-Boost Mode due to hard switching and are affected by lots of stresses which decrease the efficiency rate of the converter. In order to improve this problem, to decrease the loss of snubber and switching, it has been investigated that zero voltage switching mode and zero current switching mode which make the operation of switches with soft switching. For the more sophisticated and advanced device, this paper is presented the Partial Resonant Soft Switching Mode Power Converter which is adapted the power converter having the partial resonant soft switching mode, that makes switches operate when the resonant current or voltage becomes zero by making the resonant circuit partially at turning on and off of the switches with suitable layout of the resonant elements and switch elements in the converter. Also, this paper includes the analysis and simulation of the Partial Resonant type Buck-Boost Chopper.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.3
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• pp.65-76
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• 2000

To measure the fuel consumption rate of a vehicle, a car is tested on chassis dynamometer following given driving mode. But the fuel consumption rate measured by this method may be somewhat different from that measured in on-road driving conditions. It may be due to not considering road grade in driving modes. In this study, new driving modes which include road grade are proposed, and the simulation program to estimate the real driving fuel consumption rate of a vehicle is developed. On-road car tests to verify the simulation program are carried out and the results of the simulation are analysed and compared with those of the experiments.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.3
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• pp.122-129
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• 2001

Exact simulation of conducted EMI in switched mode power supplies is proposed. In order to achieve exact simulation, PSPICE active component ABM model and modified transformer model are proposed. Each model parameter is extracted from measurements and data-books. PSPICE simulation results with high frequency PCB pattern model are accordant with EMI measurements for a 50[W] isolated flyback converter. EMI relations of each component and EMI patterns are analyzed.

• International Journal of Internet, Broadcasting and Communication
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• v.10 no.3
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• pp.121-127
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• 2018

In this study, we propose a pseudo golf club which can sense user's swing motion and virtual golf simulation system using the pseudo golf club. The proposed system is a virtual golf simulation system of a complex play type in which a player can enjoy various types of golf play according to the user's taste by providing a play mode for hitting an actual golf ball and a play mode for swinging the pseudo golf club. This virtual golf play system calculates and displays the trajectory of a golf ball by a simulator just like playing a real golf, and suggests suitable swing motion, so it helps users to learn golf easily.