• 한국통신학회:학술대회논문집
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• 한국통신학회 1983년도 추계학술발표회논문집
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• pp.32-34
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• 1983

In this paper, an analog optical filter link is evaluated for the transmission of baseband video signals over a single fiber. LED and PIN photo diode are used as the optical source and the detector. Frequency response of the system, DP, DG and SNR are measured.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 D
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• pp.2335-2337
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• 2004

Kalman filter를 필터링에 적용할 때에 센서의 아날로그 신호에 들어오는 측정값의 잡음은 Gaussian 확률분포를 갖는다고 가정한다. 그러나 Kalman filter를 digital 컴퓨터에 적용할 경우에는 analog-to-digital converter에서 측정값의 잡음이외에도 quantization 잡음이 존재하며 본 논문에서는 이러한 경우에 quantization 영향이 Kalman filter 알고리듬에 미치는 영향을 수치적으로 분석하여 quantization을 Kalman filter 구현에 고려해야 될 사항으로 분류하고자 한다.

• 대한전자공학회논문지
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• 제22권1호
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• pp.1-6
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• 1985

Defocussed된 정지화상은 그 PSF(point spread fufction)이 rectangular 혹은 Gaussian등의 2차함수가 되며 이것과 입력화상과의 convolution으로 모델링 할 수 있음이. 알려져 있다. 그런데 이를 TV카메라의 주사선을 이용한 analog 방식으로 개선코자 할 경우에는 매 수평주사선에 관한한 1차원적인 처리가 가능하며 이 defocussed된 화상은 원래의 화상과 일정한 폭을 가진 펄스와의 수평방향으로 convolution된 결과로 해석 할 수 있음을 밝혔다. 또한 TV 카메라의 analog compound high pass filter를 사용한 복구 실험으로써 현저히 개선된 사진을 얻을 수 있있다.

• International Journal of Internet, Broadcasting and Communication
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• 제5권2호
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• pp.11-14
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• 2013

This paper describes the sigma-delta ADC/DAC digital block with two channels. The ADC block has comb filter and three half band filters. And the DAC block has 5th Cascaded-of-Integrators Feedback DSM. The ADC and DAC support I2S, RJ, LJ and selectable input data modes of 24bit, 20bit, and 16bit. It is fabricated with 0.35um Hynix standard CMOS cell library. The chip size is 3700*3700um. It has been verified using NC Verilog Simulator and Matlab Tool.

• 대한전자공학회논문지
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• 제8권5호
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• pp.20-26
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• 1971

대역통과여파기는 전달함수에 의한 진동감쇄율과 복소평면을 이용한 극좌표 응답도로써 그 특성이 설명되어 왔으나 여파기를 실제로 사용할 때에 시간에 대한 응답이 중요한 문제로 나타나는바 저주파대에서의 대역통과 여파기의 시간에 대한 응답특성을 구하고 다음단의 회로동작에 영향을 주는 요인들의 함수관계를 Analog전자계산기로 구성한 2차식 RC 능동여파기에 의해 밝혔다.

• 한국항해학회지
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• 제24권5호
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• pp.443-450
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• 2000

Before some experiments were carried out with analog bandpass filter which used for filtering the noise included in sound source signal. And this filter was constituted by condenser, register and operational amplifier. Hut these elements made the phase characteristics to differentiate in each sensing channel and cause a little of measurement error. We made new measurement system that was substituted digital filter for the analog filter in order to develop the optimal system which could find the time delay between each sensors with high accuracy. This paper describes the new system's constitution and the function of each parts. Specially three digital filters were designed and applied to the digital signal processing Part. And a series of experiments were carried out with the source＇s distance 9.53meters and the random bearing interval within the limits of $0^{\circ}$ ~ $180^{\circ}$. As a result, we have recognized that the accuracy of measurements were differentiated by the methods what kind of digital filter were adopted. And we have confirmed the facts that IIR LPF was suitable for sound source's bearing measurement and FIR LPF reduced the range measurement error.

• 로봇학회논문지
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• 제2권3호
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• pp.205-211
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• 2007

In this paper, the prototype of surface EMG (ElectroMyoGram) sensor is developed for the robotic rehabilitation applications, and the developed sensor is composed of the electrodes, analog signal amplifiers, analog filters, ADC (analog to digital converter), and DSP (digital signal processor) for coding the application example. Since the raw EMG signal is very low voltage, it is amplified by about one thousand times. The artifacts of amplified EMG signal are removed by using the band-pass filter. Also, the processed analog EMG signal is converted into the digital form by using ADC embedded in DSP. The developed sensor shows approximately the linear characteristics between the amplitude values of the sensor signals measured from the biceps brachii of human upper arm and the joint angles of human elbow. Finally, to show the performance of the developed EMG sensor, we suggest the application example about the real-time human elbow motion acquisition by using the developed sensor.

• 대한전자공학회논문지TC
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• 제40권12호
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• pp.155-160
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• 2003

ADC (Analog-to-Digital Converter) 와 DSP (Digital Signal Processor) 의 성능이 향상됨에 따라 아날로그 방식으로 처리하던 IF(Intermidiate Frequency) 대역의 신호를 디지털 방식으로 처리할 수 있게 되었다. 이를 디지털 라디오 또는 디지털 IF라 하고 이는 SDR (software definied radio) 의 초기단계라 할 수 있다. 디지털 라디오 개념을 수신단에 적용할 경우 오버샘플링에 의한 처리 이득을 얻을 수 있으며, 다중 캐리어방식의 수신단 설계가 가능하다. 디지털 수신기에서는 연산량 이득을 위해 데시메이션이 이루어지며, CIC (Cascaded Integrated Comb) 및 halfbandHalfband 필터 등이 앨리어싱방지 필터로 사용된다. 그런데, CIC 필터는 필연적으로 통과대역 내에서 롤 오프 현상이 발생하며, 이것은 수신단 필터의 통과대역 평탄도를 악화시켜서 수신성능의 저하를 초래한다. FIR 필터를 이용하여 보상해 주어야 한다. 본 논문에서는 W-CDMA 디지털 수신기의 수신성능에 최적인 CIC 롤오프 보상 필터를 설계방법을 제시하고, 설계된 필터가 CIC필터의 롤오프 특성을 보상하여 BER(Bit Error Rate)을 최소화시킴을 컴퓨터 시뮬레이션을 통해 확인하였다. 필터 성능을 검증하였다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제2권2호
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• pp.115-121
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• 2002

This paper presents an evolutionary design of digital IIR filters using the genetic algorithm (GA) with modified genetic operators and real-valued encoding. Conventional digital IIR filter design methods involve algebraic transformations of the transfer function of an analog low-pass filter (LPF) that satisfies prescribed filter specifications. Other types of frequency-selective digital fillers as high-pass (HPF), band-pass (BPF), and band-stop (BSF) filters are obtained by appropriate transformations of a prototype low-pass filter. In the GA-based digital IIR filter design scheme, filter coefficients are represented as a set of real-valued genes in a chromosome. Each chromosome represents the structure and weights of an individual filter. GA directly finds the coefficients of the desired filter transfer function through genetic search fur given filter specifications of minimum filter order. Crossover and mutation operators are selected to ensure the stability of resulting IIR filters. Other types of filters can be found independently from the filter specifications, not from algebraic transformations.

• 전기학회논문지
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• 제67권2호
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• pp.255-260
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• 2018

This study is focusing on the trade-offs between the passband ripples and transition bands of the Chebyshev BPF, which is converted by using the Chebyshev LPF that is well known as a proto-type analog filter. It is also focusing on the trade-offs between the passband ripples and transition bands of the cascading Chebyshev BPF, as well as, the trade-offs between the two BPFs. The study finds the frequency responses of the proto-type analog LPF, the Chebyshev BPF and the cascading Chebyshev BPF. The study shows the results as comparative analysis tables. The study designs the 10th Chebyshev BPF in order to analyze it easily. The simulation results show that the Chebyshev BPF decreases about 55% of the transition band for the -2.5[dB] passband ripple comparing to the -0.5[dB] passband ripple. This study shows the effectiveness and economic feasibility in the restricted frequency communication environment for the decrease of the transition band as providing the passband ripple margin.