• 대한의용생체공학회:의공학회지
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• 제2권2호
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• pp.127-140
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• 1981

This paper describes the mechanism of information processing in the nervous system through neuron pool model which is consisted of six single neural models. In the neuron pool model, summation characteristic of stimulus satisfies those of real nervous system and output impulse rate increases linearly to the input stimulus. Occlusion phenomena of the neuron pool model is approached to those of real nervous system and also if the threshold potential within sutlirninal fringe is increased, facilitation phenomena appreared. Therefore, the results of this study suggest that we can construct large neuron pool with many single neural models and verify the mechanism of information processing in the wide part of nervous system.

• 전자공학회논문지D
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• 제34D권7호
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• pp.30-36
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• 1997

Bump bonded piezoesistive silicon accelerometer was fabricated by the porous silicon micromachining and th eprocess technique of integrated circuit. The output voltage of the accelerometer fabricated on (111)-oreiented Si substrates with n/n$^{+}$n triple layers showed good linear characteristic of less than 1%. The measured sensitivity and the resonant frequency was about 743 .mu.V/g and 2.04 kHz, respectively. And the transverse sensitivity of 5.2% was measured from the accelerometer. Also, to investigate an influence on the output characteristics of the sensor due to bump bonding, the values of the piezoresistors were measured through thermal-cycling test in the temperature variation form -50 to 120.deg. C. Then, there was 0.014% resistance changes about 3.61 k.ohm., so sthe output charcteristics of the sensor was less affected by bump bonding.g.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(5)
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• pp.103-106
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• 2001

In this paper, a soft switching half-bridge converter using secondary switches for output control and conduction loss reduction is proposed. The conventional half-bridge converter must be fixed on duty cycle for soft switching. The proposed converter was consisted of two added switches in series of the secondary rectifier diodes. The main switches with constant duty cycle are operated ZVS. The secondary switches are operated ZV-ZCS. Especially, the primary switches were fixed duty cycle for maximum voltage conversion ratio. Output of converter is controlled by duty cycle or phase-shifted time of secondary switches. The conduction loss of the proposed converter can be reduced by the secondary switches. The operation characteristic, analysis, simulation and experimental results of the proposed converter are presented.

• 한국통신학회논문지
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• 제28권9B호
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• pp.751-759
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• 2003

진행형 지연선로 또는 지연선 루프를 저장 유닛으로 사용하는 시간 분할 다중합(TDM) 광 출력 버퍼의 셀 손실 확률, 셀 지연 시간 등의 성능을 분석하여 보았다. 저장 유닛으로 사용되는 진행형 지연선로는 지연선 루프보다 그 구조가 단순하고, 저장 신호의 질적인 면에서 더 우수하여, 기존 TDM 광 출력 버퍼에 사용되었다. 반면에, 지연선 루프는 루프 내에서의 셀 회전 수 조절을 통해 저장 시간을 조절할 수 있다는 점에서 진행형 지연선로보다 그 유연성이 우수하다. 따라서 지연선 루프를 저장 유닛으로 사용하는 새로운 TDM 광 출력 버퍼를 제안하였다. 제안한 TDM 광 출력 버퍼는 $10^{-9}$ 이하의 셀 손실 확률을 얻기 위해 필요한 저장 유닛의 수를 줄일 수 있음을 보였다. 그리고 저장 유닛의 수가 충분히 클 때, 두 가지 TDM 광 출력 버퍼는 동일한 셀 지연 시간 특성을 보였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.799-800
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• 2006

This thesis implemented security systems of voice awareness which is higher accessible than existing security system using biological authentication system and is inexpensive in module of security device, and has an advantage in usability. Proposed the security systems of voice awareness implemented algorithm for characteristic extraction of inputted speaker's voice signal verification, and also implemented database of access control that is founded on extractible output. And a security system of voice awareness has a function of an authority of access control to system.

• 정보학연구
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• 제10권3호
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• pp.33-45
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• 2007

Systolic Array Processor is used for designing the special purpose processor in Digital Signal Processing, Computer Graphics, Neural Network Applications etc., since it has the characteristic of parallelism, pipeline processing and architecture of regularity. But, in case of using general design method, it has intial waiting period as large as No. of PE-1. And if the connected system needs parallel and simultaneous outputs, processor has some problems of the performance, since it generates only one output at each clock in output state. So in this paper, one dimensional Systolic Array Processor that is designed according to the dependance of data and operations using the partitioned sub-matrix is proposed for the purpose of improving the performance. 1-D Systolic Array using 4 partitioned sub-matrix has efficient method in case of considering those two problems.

• Journal of information and communication convergence engineering
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• 제6권2호
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• pp.154-157
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• 2008

A class-E RF(Radio Frequency) power amplifier for wireless application is designed using standard CMOS technology. To drive the class-E power amplifier, a class-F RF power amplifier is used and the reliability characteristics are studied with a class-E load network. The reliability characteristic is improved when a finite-DC feed inductor is used instead of an RF choke with the load. After one year of operating, when the load is an RF choke the output current and voltage of the power amplifier decrease about 17% compared to initial values. But when the load is a finite DC-feed inductor the output current and voltage decrease 9.7%. The S-parameter such as input reflection coefficient(S11) and the forward transmission scattering parameter(S21) is simulated with the stress time. In a finite DC-feed inductor the characteristics of S-parameter are changed slightly compared to an RF-choke inductor. From the simulation results, the class-E power amplifier with a finite DC-feed inductor shows superior reliability characteristics compared to power amplifier using an RF choke.

• 한국음향학회지
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• 제28권8호
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• pp.832-842
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• 2009

Automatic speech recognition (ASR) has been successfully applied to many real human computer interaction (HCI) applications; however, its performance tends to be significantly decreased under noisy environments. The invention of audio visual speech recognition (AVSR) using an acoustic signal and lip motion has recently attracted more attention due to its noise-robustness characteristic. In this paper, we describe our novel integration scheme for AVSR based on a late integration approach. Firstly, we introduce the robust reliability measurement for audio and visual modalities using model based information and signal based information. The model based sources measure the confusability of vocabulary while the signal is used to estimate the noise level. Secondly, the output probabilities of audio and visual speech recognizers are normalized respectively before applying the final integration step using normalized output space and estimated weights. We evaluate the performance of our proposed method via Korean isolated word recognition system. The experimental results demonstrate the effectiveness and feasibility of our proposed system compared to the conventional systems.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권1호
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• pp.40-47
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• 2000

This paper presents a circuit of resonant voltage resultant type DC/DC converter consists of two unit half-bridge high frequency resonant inverters, and describes operating modes, principle and analysis of the proposed circuit. Also, the analysis of the proposed circuit has generally described by using normalized parameters. Based on the characteristic values, a method of the circuit design is proposed. According to phase shift, the output voltage of the proposed circuit can be controlled. In addition, the justification of theoretical analysis was certified by comparing to the experimental waveforms. In the future, this proposed converter show that it can be practically used as the system of fixed DC voltage source etc.

• Journal of Magnetics
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• 제17권4호
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• pp.285-290
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• 2012

Electric Power Steering (EPS) system is superior to conventional Hydraulic Power Steering (HPS) system in aspect of fuel economy and environmental concerns. The EPS system consists of torque sensor, electric motor, ECU (Electric Control Unit), gears and etc. Among the elements, the torque sensor is one of the core technologies of which output signal is used for main input of EPS controller. Usually, the torque sensor has used torsion bar to transform torsion angle into torque and needs linear characteristic in terms of flux variation with respect to rotation angle of permanent magnet. The torsion angle of both ends of a torsion bar is measured by a contact variable resistor. In this paper, the sensor is accurately analyzed using 3D finite element method and its characteristics with respect to four different shapes of the stator teeth are compared. The four shapes are rectangular, triangular, trapezoidal and circular type.