• 전자공학회논문지
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• 제53권11호
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• pp.66-70
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• 2016

본 논문에서는 심장박동 측정 레이더 송수신기용 24 GHz I/Q 발생기를 제안한다. 공정 변화에 따른 I/Q LO 신호간의 부정합 특성을 개선하기 위하여 인덕터와 캐패시터로 구성된 high-pass 위상천이기와 low-pass 위상천이기 기반 24 GHz I/Q LO 발생기를 제안하였다. 제안한 24 GHz I/Q 발생기는 LO 버퍼와 high-pass 위상천이기와 low-pass 위상천이기 구성된 24 GHz I/Q LO 발생기는 65 nm CMOS 공정에서 설계되었고, 전원 전압 1 V에서 8 mA의 전류를 소모하면서 24.05 GHz에서 24.25 GHz의 주파수 대역에서 7.5 dB의 전압 이득, 2.3 dB의 잡음 지수, 공정 및 온도 변화에 대해 0.1 dB의 I/Q 이득 부정합, 4.3도의 I/Q 위상 부정합의 성능을 보인다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.600-603
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• 2000

In the high carbon steel wire drawing process, the wire temperature increases as the drawing speed is faster in order to increase the production rate in the shop floor. The rapid temperature rise causes the wire fracture in the dry wire drawing process. So, in this paper, the isothermal pass schedule program, which includes the calculation method of wire temperature at each pass, is proposed to prevent the wire fracture due to the temperature rise. Using the isothermal pass schedule program, it is newly proposed the pass schedule design system that prevents the cup-cone defects, improves the elongation of the final products and assures further deformation. As a result, the temperature rise of the wire was decreased and the production rate of the final product is remarkably grown up according to the increase of the final drawing speed than that of the conventional process. Also, the proposed pass schedule design system could give a useful information to the process designer who would design the high carbon steel wire drawing process.

• 한국지진공학회논문집
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• 제28권4호
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• pp.183-191
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• 2024

Accurate seismic vulnerability assessment requires high quality and large amounts of ground motion data. Ground motion data generated from time series contains not only the seismic waves but also the background noise. Therefore, it is crucial to determine the high-pass cut-off frequency to reduce the background noise. Traditional methods for determining the high-pass filter frequency are based on human inspection, such as comparing the noise and the signal Fourier Amplitude Spectrum (FAS), f² trend line fitting, and inspection of the displacement curve after filtering. However, these methods are subject to human error and unsuitable for automating the process. This study used a deep learning approach to determine the high-pass filter frequency. We used the Mel-spectrogram for feature extraction and mixup technique to overcome the lack of data. We selected convolutional neural network (CNN) models such as ResNet, DenseNet, and EfficientNet for transfer learning. Additionally, we chose ViT and DeiT for transformer-based models. The results showed that ResNet had the highest performance with R² (the coefficient of determination) at 0.977 and the lowest mean absolute error (MAE) and RMSE (root mean square error) at 0.006 and 0.074, respectively. When applied to a seismic event and compared to the traditional methods, the determination of the high-pass filter frequency through the deep learning method showed a difference of 0.1 Hz, which demonstrates that it can be used as a replacement for traditional methods. We anticipate that this study will pave the way for automating ground motion processing, which could be applied to the system to handle large amounts of data efficiently.

• KIEE International Transactions on Electrophysics and Applications
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• 제5C권4호
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• pp.176-179
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• 2005

The increasing demand for high density packaging technologies and the evolution to mixed digital and analogue devices has been the con-set of increasing research in thin film multi-layer technologies such as the passive components integration technology. In this paper, Cu and TaO thin film with RF sputtering was deposited for spiral inductor and MOM capacitor on the $SiO_2$/Si(100) substrate. MOM capacitor and spiral inductor were fabricated for L-C band pass filter by sputtering and lift-off. We are analyzed and designed thin films L-C passive components for band pass filter at 900 MHz and 1.8 GHz, important devices for mobile communication system. Based on the high-Q values of passive components, MOM capacitor and spiral inductors for L-C band pass filter, a low insertion loss of L-C passive components can be realized with a minimized chip area. The insertion loss was 3 dB for a 1.8 GHz filter, and 5 dB for a 900 MHz filter. This paper also discusses a analysis and practical design to thin-film L-C band pass filter.

• 한국정보통신학회논문지
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• 제18권2호
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• pp.260-267
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• 2014

본 논문에서는 칩커패시터와 마이크로스트립 선로를 이용하여 LH 구조의 단위셀을 고안하고, 제안된 단위셀로부터 등가회로를 추출하여 단위셀의 제반 특성을 분석하였으며, 광대역 고역통과필터를 설계하는데 적용하였다. 이 필터는 고역통과 특성을 갖는 여러 개의 단위셀을 종속 연결하여 마이크로스트립 전송선에 구현하였으며, 그 성능은 0~2.18 GHz의 저지대역에서 62.9dB의 대역제거 특성과 3.0~12.75 GHz의 통과대역에서 1.17dB 이하의 삽입손실을 갖는다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 춘계학술대회
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• pp.157-159
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• 2010

대부분의 디지털 촬영 장치는 Charge Coupled Device(CCD) 또는 Complementary Metal Oxide Semiconductor(CMOS) 센서를 사용한다. 이러한 센서를 통해 촬영된 영상 정보에는 원하지 않는 잡음이 포함되어있다. 본 논문은 영상의 잡음 제거 및 영상 정보의 회복을 위한 기법인 잡음 제거(Noise Reduction, NR)에 관한 것이다. 제안한 NR 방법은 저역통과 필터(Low Pass Filter, LPF)의 대역폭을 고려한 잡음 제거 방법에 관한 것으로, NR의 성능개선을 위하여 MSF 연산에 사용되는 LPF의 필터 계수를 통한 시뮬레이션을 수행하였다. 필터 계수가 갖는 주파수 대역폭의 특성을 고려한 시뮬레이션 결과, MSF 연산에 적용되는 LPF와 고역통과 필터(High Pass Filter, HPF)의 필터 계수가 [1 2 1]과 [-1 2 -1]인 경우 가장 이상적인 주파수 대역폭을 나타내며, NR의 성능 또한 우수함을 확인하였다. 시뮬레이션 결과를 통하여, MSF를 수행함에 있어서 LPF와 HPF의 필터 계수를 [1 21]과 [-1 2 -1]로 제안하였다.

• 한국인터넷방송통신학회논문지
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• 제13권3호
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• pp.87-92
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• 2013

본 연구에서는 톨게이트에서 하이패스 전용차선 제한속도변경에 따른 톨게이트에서의 교통흐름의 변화와 이에 따른 환경오염에 대한 영향을 비교분석하였다. 톨게이트 시뮬레이션을 위해서 인천톨게이트 자료를 이용하였으며, 다양한 하이패스 전용차선 제한속도에 근거하여 시뮬레이션을 시행하였다. 미시적 시뮬레이션 분석을 위하여 본 연구에서는 Paramics가 사용되었다. 시뮬레이션 실행결과, 현재보다 높은 하이패스 제한속도 (70Km/h)가 기존제한속도 (30Km/h)에 비하여 톨게이트에서 교통류의 흐름에 긍정적인 영향을 미치고 환경적으로도 긍정적인 영향을 미치는 것으로 나타났다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1972-1974
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• 2004

This paper describes the high pass filter with notch charecteristics. The proposed circuits configuration consists of two uniformly distributed RC line (herein after is called URC) and two gain amplifiers ($K_1$ and $K_2$). With the appropriate $K_1$ and $K_2$ , the circuit has a steeper slope of magnitude response at pass band steeper than using a single gain amplifier.

• JSTS:Journal of Semiconductor Technology and Science
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• 제17권3호
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• pp.438-445
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• 2017

This paper presents a low-power high-resolution band-pass ${\Sigma}{\Delta}$ ADC for accelerometer applications. The proposed band-pass ${\Sigma}{\Delta}$ ADC consists of a high-performance 6-th order feed-forward ${\Sigma}{\Delta}$ modulator with 1-bit quantization and a low-power, area-efficient digital filter. The ADC is fabricated in 180 nm 1P6M mixed-signal CMOS process with a die area of $5mm^2$. This high-resolution ADC got 90 dB peak signal to noise plus distortion ratio (SNDR) and 96 dB dynamic range (DR) over 4 kHz bandwidth, while the intermediate frequency (IF) is shifting from 100 KHz to 200 KHz. The power dissipation of the chip is 5.6 mW under 1.8 V (digital)/3.3 V (analog) power supply.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권4호
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• pp.178-184
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• 2005

In this paper, using diplexer structure and varactor diode controlled by reverse bias voltage for diplexer switch gives possibilities to improve isolation and current characteristics. 1 have newly designed switch with high isolation by application varactor diode corresponding to capacitor of diplexer. The low-pass filter for proposed tunable diplexer passes the microwave signal in the bandwidth for wireless cellular network systems and high-pass filter passes it in the bandwidth for wireless personal communication services (PCS) network systems. As the capacitance of the low-pass filter increases, the cut-off frequency can be moved to low frequency, so that the switch is on state in cellular bandwidth and off state in the PCS bandwidth, in contrast to, as the capacitance for attenuation characteristic of high-pass filter increases, it can be moved to high frequency, so that the switch is off state and on state in the cellular bandwidth. it is possible to improve isolation and current consumption characteristics by application diplexer design methods and varactor diode. 1 expect that the tunable diplexer circuit and design methods should be able to find applications on MMIC and low temperature copired ceramic (LTCC).