• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.2
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• pp.64-69
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• 2003

In this paper, I introduce a simple design method using existing filter design method, such as Parks-McClecllan algorithm, for root-squared type raised cosine filter with equiripple characteristics, Thought some design examples, we show that the proposed filter has much better performance in ripple than the conventional SRCF at the expense of small increasing of ISI. In addition, the proposed filter is compatible with conventional SRCF. Finally, the filter for W-CDMA which uses RRC (Root Raised Cosine) with a=0.22 is designed in 12bit finite precision.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.2B
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• pp.160-169
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• 2002

While radar operator recognizes and tracks threat targets through the scope, it is essential to overcome the jamming signal that disturbs the normal operation of the radar. Therefore, to train operator and test the EW capability of the radar, this paper proposed the jamming signal simulation algorithm and design results to generate the deception jamming(range, velocity, angle deception and multiple false targets) and noise jamming signals(spot, barrage, swept spot and cover pulse noise). And also, the radar jamming signal simulator composed of the 6 constituents is developed on basis of the proposed algorithm and digital circuit design technique and confirmed the validity of the developed simulator by means of the test results to generate the various jamming signal.

• Journal of Advanced Marine Engineering and Technology
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• v.11 no.2
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• pp.37-50
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• 1987

In an effort to conserve electric power, variable voltage variable frequency pulse width modulated (PWM) inverters are being applied increasingly to the variable speed control of the induction motors. The use of the PWM technique in motor drive applications is considered advantageous in many ways. For industrial applications, the PWM drive obtains its DC input through simple uncontrolled rectification of the commercial AC line and is favored for its good power factor, good efficiency, its relative freedom regulation problem, and mainly for its ability to operate the motor with nearly sinusoidal current waveforms. The purpose of this paper is to design a three phase natural sampled PWM inverter using microprocessor with simple control algorithm and hybrid control circuit has been built to implement this PWM scheme. In this system, the microprocessor can be used only for calculations directly related to motor control tasks by the design of hybrid circuit which sends PWM signals to the motor.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.151-154
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• 2001

In this paper, a two-level switching algorithm of the deadbeat to control PWM inverter is proposed. A modified algorithm of the deadbeat is suitable for the UPS system. Two levels in the pulse pattern are used. This scheme allows the use of higher switching frequency for a given computation time delay, which results in lower total harmonic distortion at the output. The proposed control scheme is implemented using TMS320F240 DSP chip for controlling on inverter.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.163-166
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• 2001

In this paper, a two-level switching algorithm ov the deadbeat to control PWM inverter is proposed. A modified algorithm of the deadbeat is suitable for the UPS system. Two levels in the pulse pattern are used. This scheme allows the use of higher switching frequency for a given computation time delay, which results in lower total harmonic distortion at the output. The proposed control scheme is implemented using TMS320F240 DSP for controlling on inverter.

• Proceedings of the KIEE Conference
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• 1991.11a
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• pp.357-360
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• 1991

In this paper, we have introduced a network and showed how this can be realised as an adaptive equalizer. The walsh equlizer is built from a set of Walsh-Block pulse functions and LMS algorithms with the optimal convergence factor(C.F.). The convergence and the adaptation speed of this algorithms depends on the proper choice of a design factor $\mu$ called the C.F.. Conventional adaptation techniques use the fixed time constant C.F. by the method of trial and error. In this paper, we propose to adaptive C.F. which are optimally tailored to adapt C.F. in real time so that their values are kept optimum for a new set of input variables.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2002.05a
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• pp.10-13
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• 2002

In this study, we used a 16-bit microprocessor, 80C196KC for a control part in order to develop a multi-functional wheel-chair system, and implemented a joy-stick to control this system. For the complete system, we used a commercial electromotive wheelchair as a basic plant, and applied an encoder to get the rotating number of the motor to transfer data to the MCU to control the motor. We used PWM (Pulse Width Modulation) method to control the wheel-chair motor where a H-bridge circuit was configured. We used the fuzzy control algorithm for the operation of DC motor, which was attached to the electromotive wheelchair and manipulated following the change of the joystick position while a user was controlling the Joystick. He also could control the speed and direction of DC motor as well as control position information.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.11
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• pp.949-958
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• 2016

This paper presents the new development result of the multi-band, the multi-mode SDR(Software Defined Radar) platform. The SDR hardware platform is implemented by using the reconfigurable multi-band RF transceiver and antenna modules of S, X, and K-bands, and a programmable signal processing module. The SDR software platform is implemented by using the multi-mode waveform generation of CW, Pulse, FMCW, and LFM Chirp as well as the adaptable algorithm library of signal processing and open API software modules. Through the integrated test of the SDR platform, the operational performance was verified in real-time. Also, through the field-application test, the ground target and air-vehicle drone target were successfully detected and their test results were presented.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.3233-3235
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• 2000

A new method for HRV(heart rate variability} detection from the R-wave signal, based on the IPFM (integral pulse frequency modulation) model and its similarity to pulse position modulation, is presented. The proposed method exert lowpass filtering with a Kaiser window. In this paper, The proposed method presents a powerful, but simple, tool for investigation of HRV. It also guarantees real-time behavior, simplicity in design, and phase linearity. Even without the basic assumption of IPFM model, the new algorithm can still be used on-line and with higher performance. It is thoroughly proved that lowpass filtering is an ideal method for PSD (Power Spectrum Density) analysis of HRV.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.1
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• pp.16-23
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• 2016

The EWB(electronic wedge brake) is one in which the braking force is developed in a wedge and caliper system and applied to a disk and wedge mechanism. The advantage of the wedge structure is that it produces self-reinforcing effect and hence, utilizes minimal motor power, resulting in reduced gear and current. The extent of use of clamping force sensors and protection from failure of the EWB system directly depends on the level of vehicle mass production. This study investigated the mathematical equations, simulation modeling, and failsafe control algorithm for the clamping force sensor of the EWB and validated the simulations. As this EWB system modeling can be applied to motor inductance, resistance, screw inertia, stiffness, and wedge mass and angle, this study could improve the accuracy of simulation of the EWB. The simulation results demonstrated the braking force, motor speed, and current of the EWB system when the driver desired to the step and pulse the brake force inputs. Moreover, this paper demonstrated that the proposed failsafe control algorithm accurately detects faults in the clamping force sensor, if any.