This paper describes the modeling and experimental results of coreless printed circuit board (PCB) based transformer that can be used for power conversion at high frequency operation. The principle of using coreless PCB based transformer in 2MHz, 10W class ZVS Flyback DC-DC converter has been successfully demonstrated. The maximum power conversion efficiency is 79%. Even for high operating frequency, an efficiency greater than 70% can be obtained with under 1% regulation error.

This paper presents a simple class-D stereo amplifier using 3-phase full bridge circuit configurations which is controlled by a new current control switching method. Although this class-D amplifier has an only one current control loop with the proposed switching method, a good performance can be obtained. In this paper, a strategy for driving stereo signal amplifier with 3-phase full bridge is discussed. With the experimental results, usefulness of the proposed amplifier is confirmed.

Usually, in many applications, high frequency resonant inverters are used, and the PAM(Pulse Amplitude Modulation), PFM(Pulse Frequency Modulation) or PWM(Pulse Width Modulation) techniques are used to control the output power of resonant inverters. In this paper, a new switching scheme is proposed as a PWM control method. With the proposed method, it can be obtained that unity output displacement factor under the variable resonant frequency. The detail algorithm of the proposed PWM switching scheme and its charicteristics are discussed. And the validity of the proposed method is confirmed with the experimental results.

Generally, the wheel-driven mobile robot systems, by their structural property, have nonholonomic constraints. These constraints are not integrable and cannot be written as time derivatives of some functions with respect to the generalized coordinates. Hence, nonlinear approaches are required to solve the problems. In this paper, the trajectory controller of wheeled mobile robot systems is suggested to guarantee its convergence to reference trajectory. Design procedure of the suggested trajectory controller is back-stepping scheme which was introduced recently in nonlinear control theory. The performance of the proposed trajectory controller is verified via computer simulation. In the simulation, the trajectory controller is applied to differentially driven robot system and car-like mobile robot system on the assumption that the trajectory planner be given.

In this paper, we propose a new approach to determination of environment forces acting on a rigid body. To estimate the output of disturbance observer due to internal torque, the disturbance observer output estimator using functional link neural network (FLANN) is designed. It is also shown by simulation results that the precise estimation of contact force is achieved for a 2-link SCARA robot performing position/force control.

In this paper, we design an optimal path for multiple mobile robots. For this purpose, we propose a new method of path planning for multiple mobile robots in dynamic environment. First, every mobile robot searches a global path using a distance transform algorithm. Then we put subgoals at crooked path points and optimize them. And finally to obtain an optimal on-line local path, ever)r mobile robot searches a new path with static and dynamic obstacle avoidance.

Since the telemanipulator consisting of high reduction ratio gear joints has a slow dynamics comparing with the master manipulator, its control signal is likely to be saturated resulting in poor tracking performance and deteriorated stability. This paper proposes a bilateral control scheme of a telemanipulator having high reduction ratio, which can compensate the control input saturation. The experimental results show that the proposed control scheme has excellent performances.

In this paper we design the robust impedance controller of the robot manipulator with time delay. The designed controller considers time delay in the position loop and stabilizes the closed-loop system. The performance of a controller can be easily degraded by external disturbances. To improve the performance when external disturbances exist, we use the disturbance observer to handle the disturbances in the velocity loop and provide robustness to the control system. To show the validity of the designed controller, several experiments are performed for the 5-DOF robot manipulator equipped with the wrist force/torque sensor system.

In this paper, we present a method for vehicle tracking systems using $\alpha$-$\beta$ filter based on fuzzy logic. The $\alpha$-$\beta$ filter estimates the future target positions using fixed $\alpha$.$\beta$ coefficients. We utilize the fuzzy logic to make $\alpha$ and $\beta$ coefficients very with the position. Comparisons of tracking performance made for three different schemes: the $\alpha$-$\beta$ filter, $\alpha$-$\beta$filter using fuzzy logic, and the kalman filter.

In this paper, we propose PID type direct control method using single neuron neural network. The proposed method has an output error and 2 time-delay as inputs and is designed to have input weights composed of P, I, D parameters to be controlled through teaming. We could verify the better performance of this system than the conventional method through simulations. And the reduced calculation, due to single neuron, makes it possible the real time processing, and the simple implementation.

We are concerned with processing methods of the measurement values of sensors in the control system. When some faults happen to sensor components, the measurement value of sensors cause the malfunction of the plant. So it is necessary to detect and reduce the influence of faults to control with reliability for the overall system. The sensor status must be always good for best demonstration of the controller performance. A self-validating sensor detects the sensor state from the measurement value, reconstruct a soft sensor and can improve reliability of the sensor. If sensor faults, the sensor is detected and reconstructed with the best estimate from its correlation to other sensors and historical data. It is applied to the control of a flexible link system with the sensor fault problems in the light sensor module for position to show the applicability. In this paper, we propose a digital controller which reduces deflection of the moving set-point by reconstructing output of a sensor when the sensor fault is detected.

Previous works using a Multi-population Genetic Algorithm have divided chromosome into two components, rule sets and membership functions. However, in this case bad rule sets disturb optimization in good rule sets and membership functions. A new method for a Multi-population Genetic Algorithm suggests three components, good rule sets, bad rule sets, and membership functions. To show the effectiveness of this method, fuzzy controller is applied in a Truck Backing Problem. Results of the computer simulation show good adaptation of the proposed method for a Multi-population Genetic Algorithm.

This paper describes a RF Down-Conversion Mixer for mobile communication systems. This circuit achieves low voltage operation and low power consumption by reducing stacked devices of conventional gilbert cell mixer. In order to reduce stacked devices, we use source-follower structure. The proposed RF Down-Conversion mixer operates up to 1.85GHz at 1.5V power supply with 0.25um CMOS technology and consumes 2.2mA.

We design a new driving system of 5" true color FED using current controlled PWM method. Further more, we successfully developed a 5" FED panel, which resolution is 320$\times$240(Color). When we design a 5" FED driving circuit, FED tips are modeled as R-C for circuit simulator of FED driving circuit. In Video data processing, parallel R, G, B input signals is processed independently, so duty ratio increase and no noise, high quality performance is achieved in display of 5" FED. The luminance is about 100cd/$m^2$, the anode power consumption Is 2.1W and total power of the driving system is 21.54W

This paper describes an SRAM write driver circuit which dissipates small power. The write driver utilizes a dual sized transistor structure to reduce operating current in the write cycle. In the case of higher voltage comparing to Vcc, only one transistor is active, while in the case of low Vcc two transistors are active so as to deliver the current twice. Thus though with the high voltage operation, the power consumption is reduced with keeping the speed in a given specification. Simulation results have verified the functionality of the new circuit and write power is reduced by 7 % per bit.

We study the Chua oscillator circuit by considering a negative resistor as a characteristic parameter which controlled by the CdS(Cadmium Sulphide) cell. This is a new way to observe several chaotic phenomena with the same initial condition continuously. Since we can control the internal resistance of the CdS cell by an additional circuit, our autonomous chaotic oscillator circuit makes it possible to measure the voltage value continuously and automatically.

This paper describes a new method to decide the margin for the sustain voltage of AC PDPs based on the wall-charge distribution. We model the discharge cell and measure the wall-charge when sustain pulses are applied to the AC PDP. The measured wall-charge distribution informs us of the voltage forming the maximum wall-charge which should be chosen as the sustain voltage.

This paper proposes a new sigma delta modulator structure based on a LMS(Least Mean Square) algorithm that minimizes the quantization noise. The proposed architecture provides 40dB SNR improvement and 35dB wider dynamic range over conventional sigma delta modulation. The proposed architecture provides superior performance especially when the input signal is small.

This paper describes a Band-Selective Charge-Pump PLL(CPPLL) for clock recovery and clock generator. The proposed PLL satisfies fast acquisition time and low jitter characteristics simultaneously by reducing initial frequency error. The acquisition time of the designed Band-Selective CPPLL can be decreased down to 55% of a conventional CPPLL.

A wire communication module for PLC controller was developed. This system consists of RF module interface part, RS232 serial communication control part, LED display part and control S/W with GUI interface. RF communication frequency is controlled by PLL controlling and communication rate is also controlled as 1200 and 4800 bps. Communication and control status are displayed on LED. As a S/W part, graphic user interface on Window 95 O.S. was developed. To show the validity of the developed system, severial communication and control of PLC system were experemented.

Evaluation of the acoustic nasal geometry is obtained by estimating impulse response due to the nasal geometry. Conventionally, the Wiener filtering method proposed by Hunt has been used for estimating impulse response. In this paper, we proposed the Weiner filtering method using noise-to-signal power ratio for estimating impulse response. In result, the proposed method in this paper is effective than the conventional method.

This study analyze of reflection wave to Acoustic stimulation on acupoints and contrast parts for objectification of the meridian substance. In order to verify meridian pathway and channel theory of bio-energy in body. It was analyzed response characteristic of reflection waves after acoustic stimulation by sound wave of 5 specific tones. The response characteristics of reflection are measured by the average current magnitude of meridian. The current variation ratio are Live Meridian(gung) 33.2%, Heart Meridian(sang) 30.7%, Kidney Meridian (gak) 33.1%, Spleen Meridian(chi) 33.9%, Lung Meridian (wo) 30.7% compare with contrast parts (non-acupoint and meridian). Therefore meridian is distinguished to non-meridian and 5 vital meridians have relationship with sound wave of 5 specific tones.

Optokinetic nystagmus(OKN) testing is an useful tool for assessment of human visual function. Specially, this method has been used for assessing visual function in infants and malingering patients. OKN drum and OKN tape are the common devices currently used for clinical cases. In this paper, we present newly the automated and computerized method for the quantitative and objective assessment of visual acuity in OKN testing.

The diode characteristics for therapy radiation sensor have been studied by irradiating therapy radiation from the MM22 microtron accelerator. Signal processing has been performed in the pulse mode which can process the signal fast. We have designed integrator, peak detector and synchronization circuit to detect diode signal in the pulse mode for implementation of portal image. We also read the diode signal by A/D board and displayed the peak value with LabView program. Because the quality of portal image obtained by film in the case of therapy radiation is much worse than that of diagnostic film, Digital radiography system by rectifier diode detector was suggested for portal Image.

Recently, the interest and the importance of the signal monitoring and recording during sleep is increasing. Conventional paper based recording systems are being replaced by digital type and polysomnographic system. We developed special digital signal processor system for the polysomnographic recording. This system consists of digital signal processing part and PC interface part for user's convenience. This system includes two digital filters, one fur low pass filtering of high frequency noise and the other for notch filtering of 60Hz AC noise. This system can be used for the efficient and convenient measurement of polysomnographic signals and also can be developed for the portable use.

In this paper presents the portable wireless ECG data detection and diagnosis system based on discreet wavelet transform. An algorithm based on wavelet transform suitable for real time implementation has been developed in order to detect ECG characteristics. In particular, QRS complex, S and T waves may be distinguished form noise, baseline drift or artifacts. Proposed telemetry system that a transmitting media using radio frequency(RF) for the middle range measurement of the physiological signals and receiving media using optical for electromagnetic interference problem. A standard hi-directional serial communication interface between the telemetry system and a personal computer or laptop, allows read-time controlling, diagnosing and monitoring of system. A portable telemetry system within a size. of 65${\times}$125${\times}$45mm consists of three parts: a digital signal processing part for physiological signal detect or diagnose, RF transmitter for data transfer and a optical receiver for command receive. Advantages of proposed telemetry system is wireless middle range(50m) FM transmission, reduce electromagnetic interference to a minimum. which enables a comfortable diagnosis system at home.

Pulse oximetry is a well established non-invasive optical technique for monitoring the SpO$_2$ during anaesthesia, recovery and intensive care. Pulse oximeters determine the oxygen saturation level of blood by measuring the light absorption of arterial blood. The sensors consists of red and infrared light sources and photodetectors. In the measurement of the hemoglobin oxygen saturation, conventional method has required the technique of filtering of remove the noise, and of complex signal processing algorithm. So much time have required to signal processing. In this research, we separate AC signal and DC signal in the stage of signal detection. We filter the noise from each signal and convert A/D. We obtain the SpO$_2$ using the DSP algorithm.

Changes in breathing pattern and apnea both can be !he result of sleep disorders. The focus of this paper is to develop methodologies to monitor the breathing pattern and to detect apnea. An accurate recording of the respiratory phase can be carried out with different methods. One of these methods is the use of a thermocouple, which reacts to the variation in air temperature, placed in the nose and mouth of the patient. The K-type thermocouple was used because it has high reliability, thermo-stability, and good corrosion resistance. And also, it has a considerable long time constant that gives a low cut-off frequency, well below the respiratory frequency and thereby causing a large phase difference. The result showed that timing of respiration was accurately obtained with the AD595, amplifier for K-type thermocouple.

The Minimum-Norm Least-Square(MNLS) approach based on lead field theory is an useful method to find an unique inverse solution for the measured magnetic field. The lead field depends on head geometry and location of sources and sensors. So, optimization of sensor array location is important issue for MNLS estimation. In this paper, we present an investigation for the optimization of sensor array location in computer simulation.

Classification of Electroencephalogram(EEG) makes one of key roles in the field of clinical diagnosis, such as detection for epilepsy. Spectrum analysis using the fourier transform(FT) uses the same window to signals, so classification rate decreases for nonstationary signals such as EEG's. In this paper, wavelet power spectrum method using wavelet transform which is excellent in detection of transient components of time-varying signals is applied to the classification of three types of Event Related Potential(EP) and compared with the result by fourier transform. In the experiments, two types of photic stimulation, which are caused by eye opening/closing and artificial light, are used to collect the data to be classified. After choosing a specific range of scales, scale-averaged wavelet spectrums extracted from the wavelet power spectrum is used to find features by Back-Propagation(13P) algorithm. As a result, wavelet analysis shows superiority to fourier transform for nonstationary EEG signal classification.

In this paper, we proposed a new method for localizing the independent sources generating the observed EEG based on independent component analysis (ICA). The performance of the algorithm was tested through computer simulations.

We applied the ICA method to separate the ventricle and tissue components and to extract left ventricular input function from the H$_2$$^{15}$ O myocardial PET under the assumption that the elementary activities of ventricular pools and myocardium were spatially independent, and that the mixture of them composed dynamic PET frames. ICA-generated left ventricular input functions were compared with the ROI-generated ones, and also with the invasively derived arterial blood samples. Moreover, the rMBF calculated with the ICA-generated input functions and single compartment model was correlated with the results obtained with the radiolabeled microspheres.

In this paper, we present a new interpolation algorithm for three-dimensional images. Generally, Image interpolation is carried out along the three orthogonal coordinates. However, such a interpolation algorithm along orthogonal coordinates do not utilize the contour of 3 dimensional objects. In this paper, we propose a new directional interpolation algorithm that searches the best interpolation direction for 3-dimensional objects. Experiments with brain MR images show promising results.

Manual and predictive defrosting method is used in current refrigerators, which have several problems in terms of energy consumption and efficiency. fuming the defrosting system on by the amount of frost remains to be an important problem which has to be improved by refrigerator manufacturers. The sensing of the amount of frost by FDS(Frost Detecting Sensor) and its proper mounting point are investigated in the paper. Also the realization of actual defrosting system through experiments of operation, energy consumption and sensing mechanism is presented.

Used analog control systems have been converted into digital control systems due to performance degradation and difficulty of maintenance. There are few domestic DCS (Distribued Control System)s that have been applied to Bower plant. To apply a demestic DCS to power plant, the reliability, redundacny, and fault tolerance of DCS is important. Besides those items, the control action of control function block is also important. In this paper, we describe the requirements that PID control function block has to have, and implement a PID control function block that satisfies those requirements. Finally. simulation result using digital simulator for boiler system in thermal power plant shows the validity of a implemented PID control function block.

In this paper, For operator's conveniency of the mobile robot, achieved the system which control the robot by adopting the speaker independently isolated word recognition and by implementing the real time with TMS320C31. and This paper using the Tri-ultrasonics range finder to detect obstacles and implements the mobile robot. In this paper, DSP processor (TMS320C31) is used signal processing for speech recognition in the real time and Micro processor(80C196KC) is controling the ultrasonics range finders.

This paper addresses the design and implementation problem of the mobile robot with the synchronous driving mechanism that consists of modular control systems based on the Universal Serial Bus (USB). Recently, the USB have attracted the hardware developers'interests due to its low cost, compatibility, and extenability. In particular, the USB enables us to organize the whole system in the modular manner very easily, and this property plays a very important role in shortening the developing time in implementing the target system, for example, the mobile robot system. In this paper, we implement the USB motion controller and the USB ultrasonic sensor system and verified the validity and the effectiveness of the proposed system through the real experiments including the mobile robot navigation and the environment recognition.

This paper describes the principle of humidity sensor using high frequency resistance method for Hopper-Scale that is used in RPC(Rice processing Complex) which is spreaded out in domestic, and we also understand the principle and specificity of controller and humidity sensor. After artworking the humidity sensor and controller circuit, we measure the humidity of the designed system. In this progress, we suggested substitute parts which are easy to get in domestic and also we could propose correct method of humidity detection.

In this paper, we develope a intelligent monitoring system of Coastal Ocean Environment based on WWW(World Wide Web) and PCS(Personal Communication System). This system have capability of real time processing of enviromental variable from various sensors. The system is composed of three part. The first part is mathematical modeling of real ocean. The second is construction server for real time web page. And the third is developing the measurement system which has wireless(PCS) interface to server.

In stead of RF module which has been used conventionally in many remote measurement applications, a new type of remote measurement system based on PCS(Personal communication system) and one chip Microcontroller is proposed in this work. PCS has many advantages with respect to cost reliability, communication quality, and so on. The proposed system consists of three different modules: PCS module, micro-controller module, and sensor module. System configuration as well as illustrative experiments will be described in detail.

We propose a new method to deal with the optimized auto-tuning for the PID controller which is used to the process-centre] in various fields. First of all, in this method, initial values are determined by the Switched Reluctance Motor of system and Ziegler-Nichols method. After deciding binary strings of parents generation using by the fitness values of genetic algorithms, we perform selection, crossover and mutation to generate the descendant generation. The advantage of this method is better than the neural network and multiple regression model method in characteristic of output, and has extent of applying without limit of initial parameters.

We have proposed a new driving method of AC PDPs for high resolution and high luminance, in which address pulses shorter than 1 $\mu$sec and increase address time, make it possible to drive 2100 scan lines The proposed driving scheme also allows high sustain frequency, leading to improved luminance. The experiment with a 4-inch color AC PDP with 30$\times$58 pixels realized a high luminance of 850cd/$m^2$ when the sustain voltage of 140v with the frequency of 125KHz is applied to the panel, and showed the possibility of the proposed driving scheme for high luminance and high resolution AC PDPs with 2100 lines.

In this paper we propose a new architecture of a programmable digital automatic gain controller(AGC) for analog interface in mixed mode systems. Compared with conventional analog AGCs which have difficulties in integration due to large capacitors, the proposed AGC is easily integrated. So the production cost can be reduced. In addition, The proposed AGC has a better performance in temperature, and power supply variations, and substrate noise than analog counterparts do. To prevent erroneous operations of the AGC due to noise, a mal-function preventer is newly proposed. In addition, to achieve an optimized AGC time constant, we propose a logic block which controls an up-down counting clock. This is directly related to the changing speed of the AGC gain. Implemented with a 0.25 $\mu\textrm{m}$ 1-poly, 5-metal CMOS parameters, the AGC operates from a single 2.5V power supply with the dynamic range of 36.ldB and occupies active area of 500$\mu\textrm{m}$${\times}$600$\mu\textrm{m}$

We presents the construction of radio frequency pad area array package modules which operate at radio frequency of 224MHz, and proposes the structure of RF module packages to improve its electrical characteristics. The module of RF PAA package was constructed in the configuration of three dimensional stacked package and reduced size. RF PAA packages showed the optimized and improved gain of 2dB by partitioning the RF transceiver with 3 dimensional stacked PAA packages.

A 2.4 GHz single ended two stage low noise amplifier(LNA) is designed for Bluetooth application. The circuit was implemented in a standard digital 0.25 $\mu\textrm{m}$ CMOS process with one poly and five metal layers. At 2.4 GHz, the LNA dissipates 34.5 mW from a 2.5V power supply voltage and provides 24.6 dB power gain, 2.85 dB minimum noise figure, -66.3 dB reverse isolation, and an output 1-dB compression level of 8.5 dBm.

A CMOS power amplifier for wireless home networks is designed using 0.2sum 1-poly 5-metal standard CMOS technology and simulation results are presented. The power amplifier provides maximum output power of 16.5dBm to a 50-Ohm load at 2.450Hz and dissipates 220mW of dc power from a single 2.5-V supply. The designed CMOS power amplifier has power control range of 20dB and an overall power-added efficiency of 17%

RFID (Radio Frequency Identification) is a technique which is used for identifying different types of objects and tracking people and animals. Passive RFID consists of reader, a passive tag. The reader transmit energy to a tag and read information back from tag. The tag is energized by a carrier frequency which is transmitted by the reader and transmit information back to the reader. In this paper, the circuit for read and write RFID system is presented. The presented RFID system adopts 125kHz carrier frequency, backscattering and PSK for communication method.

Depending upon the existence of the battery, transponder is divided into active and passive transponder. The passive transponder operates without the inner battery and so has no limitation in its operating range and life time. But the power consumption in the smartcard should be low. In this paper, the analysis and design of the passive smartcard system oerated at 125kHz is presented and is confirmed by simulation and experiment.

In this paper, we developed a feature point detection algorithm that detects upstroke point(S), peak point(P), incisura(C) point from radial pulse waveform which obtained by using the developed radial pulse transducer. As the results of experiment the three kinds of parameters can extracted with effectively from normal radial pulse waveform.

In this paper, we studied about the effects of EGG to the gastric meridian stimulation based on meridian theory in oriental medicine. We implemented the 4channel EGG system to obtain EGG signal and analyzed EGG signals by using STFA before and after acupuncture stimulation. We han experiment with 7 subjects and compared EGG signal with before and after acupuncture stimulation of Jocsamly hyul(S36) in gastric meridian. As a result of experiment, the center frequency of stimulating EGG power spectrum was upper shifted to 3.8mHz than that of nonstimulation. We can see that the gastric-meridian stimulation enhance gastric motility.

To help the blind to find the information easily on World Wide Web, this research has tried to develop the device which enables us to convert HTML for the general into HTML for the blind. This program consists of the items as follows: 1. Web Robot to gather the internet browser and the general HTML. 2. Restoring DB by Parsing process 3. Multimedia editor for the use of web DB to add the literal and acoustic description to the editing function. 4. Convertor which gathers the DB and then changes into HTML for the blind. This project is designed to make it easy for the manager to establish the web site for the blind. We expect that this program will basically help the blind to overcome the inequality in the common information.

The electronystagmography(ENG) means to measure and record CRP(Corneal-Retinal Potential) whenever the eyeball is moved by using a skin electrode stuck to the hi-temporal and the difference of CRP. Both the horizontal and vertical movement are known according to the position of the stuck skin electrode. In this paper, the variable time-constances to record the eyeball signal of the conventional EOG(Electro-Oculograph) Amplifier is chosen. The shorter the time-constance is, the worse the distortion of a signal is. But the unbalanced impedance of the electrode stuck on the hi-temporal is reduced. Also, the longer the time-constance is, the less the distortion of it signal is. But it is sensitive to the change of base line according to the unbalanced impedance. In order to solve these problems, an DC-Amplifier, the distortion of the eyeball signal is globally used. By solving unbalanced impedance problem of EOG amplifier, the distortion ratio of EOG amplifier is improved.

This Paper investigates the speed control of Switched reluctance motor(SRM) using one chip microcomputer The SRM has the advantages of simple structure low rotor inertia. and high efficiency. The Position sensor is essential in SRM in order to synchronize the Phase excitation to the rotor position. The proposed system consists of phase locked loop controller, switching angle controller and inverter. The Performances in the Proposed system are verified through the experiment.