• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
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• pp.1771-1772
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• 2006

In this paper, we considered multiple faults detection on a coaxial cable through Time-Frequency Domain Reflectometry (TFDR). It is well known that TFDR has high resolution accuracy for detecting and estimating the fault detection on a coaxial cable. This approach was based on time-frequency signal analysis and utilized a chirp signal multiplied by a Gaussian time envelope. The Gaussian envelope provided time localization, while the chirp allowed one to excite the system interest. We carried out experiments with 10C-FBT coaxial cable having either one or two faults. The result shows TFDR can be extended to detect multiple faults with high accuracy on a coaxial cable.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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• pp.383-386
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• 2008

We developed a fiber-optic Bragg grating sensor system using a SOA fiber laser for over heat detection in power systems. To compensate the nonlinear wavelength tuning of the fiber laser, we used fixed passband wavelengths from Fabry-Perot ITU filter as reference wavelengths. Gaussian line-fitting algorithm was also used to reduce the FBG peak detection error. Compared with a highest-peak-detection and a polynomial-fitting method, the proposed Gaussian fitting algorithm could drastically reduce the measurement errors. Also the SOA fiber laser made it possible to enhance the signal-to-noise-ratio even with several kilometers of lead fiber.

• 센서학회지
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• 제23권3호
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• pp.149-157
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• 2014

This paper considers the ability of counting and positioning multi-targets by using a mobile UWB radar device. After a background subtraction process, distinguishing between clutters and human body signals, the position of targets will be computed using weighted Gaussian mixture methods. While computer vision offers many advantages, it has limited performance in poor visibility conditions (e.g., at night, haze, fog or smoke). UWB radar can provide a complementary technology for detecting and tracking humans, particularly in poor visibility or through-wall conditions. As we know, for 2D measurement, one method is the use of at least two receiver antennas. Another method is the use of one mobile radar receiver. This paper tried to investigate the position detection of the stationary human body using the movement of one UWB radar module.

• Journal of information and communication convergence engineering
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• 제8권4호
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• pp.405-410
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• 2010

Image processing operations like smoothing and edge detection, and many more are very widely used in areas like Computer Vision. We classify the image processing domain as seven branches-image acquirement and output, image coding and compression, image enhancement and restoration, image transformation, image segmentation, image description, and image recognition and description. We implemented algorithms of gaussian smoothing, laplace sharpening, image contrast effect, image black and white effect, image fog effect, image bright and dark effect, image median filter, and canny edge detection. Such experimental results show the figures respectively.

• 대한전자공학회논문지
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• 제24권5호
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• pp.733-739
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• 1987

In this paper, variable threshold detection with weighted pulse code modulation-encoded signals transmitted over Gaussian channels has been investigated. Each bit in the \ulcornerlaw PCM word is weighted according to its significance in the transmitter. It the output falls into the erasure zone, the regenerated sample replaced by interpolation or prediction. To overall system signal to noise ratio for BPSK/PCM speech signals of this technique has been found. When the input signal level was -17 db, the gains in overall signal s/n compared to weighted PCM and variable threshold detection were 5 db and 3 db, respectively. Computer simulation was performed generating signals by computer. The simulation was in resonable agreement with our theoretical prediction.

• 한국인터넷방송통신학회논문지
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• 제22권5호
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• pp.69-73
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• 2022

본 논문에서는 LoG(Laplacian of Gaussian) 기반의 윤곽선 검출 기법을 통한 새로운 미세먼지 측정 방법을 제안한다. 미세먼지 측정을 위하여 CCTV 기반의 영상 이미지를 수집하고, RoI(Region of Interest)를 통해 이미지 범위를 지정한다. 지정된 영역에 GMM(Gaussian Mixture Model)을 적용하여 군집화 후, LoG 알고리즘을 통해 윤곽선을 검출하고 검출된 윤곽선 강도를 측정한다. 측정된 윤곽선의 강도 데이터를 기반으로 미세먼지의 농도를 결정한다. 본 논문에서 제안하는 알고리즘의 효용성을 입증하기 위하여 본교 연구실 주위에 설치된 CCTV 영상 이미지를 6~7월 한달간 수집하여 적용한 결과, 측정된 결과값은 미세먼지 농도와 범위를 계산하기에 충분함을 본 실험을 통해 입증하였다.

• 전기전자학회논문지
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• 제28권1호
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• pp.6-13
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• 2024

본 논문에서는 비지도학습 모델인 오토인코더와 가우시안 커널 밀도 추정 함수를 이용하여 차량용 CAN 네트워크에서 비정상적인 데이터를 탐지하는 방안을 제안한다. 제안하는 오토인코더 모델은 정상 데이터에서 CAN 프레임의 ID만으로 학습시킨다. 이후 가우시안 커널 밀도 추정 함수를 이용하여 구한 최적의 프레임 개수와 손실 임계값을 가지는 모델을 사용하여 비정상 데이터를 효과적으로 탐지한다. DoS 공격, Gear 스푸핑 공격, RPM 스푸핑 공격, Fuzzy 공격 등 4가지 공격 데이터로 오토인코더 기반 IDS를 검증하였으며 성능을 평가하였다. 기존 비지도학습 기반 모델들과 비교했을 때 우수한 성능을 나타냈으며 모든 평가 지표에서 99% 이상의 성능을 나타냈다.

• 한국통신학회논문지
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• 제39C권10호
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• pp.909-919
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• 2014

License plate (LP) detection is the most imperative part of an automatic LP recognition (LPR) system. Typical LPR contains two steps, namely LP detection (LPD) and character recognition. In this paper, we propose an efficient Vehicle-to-LP detection framework which combines with an adaptive GMM (Gaussian Mixture Model) and a cascade of boosted classifiers to make a faster vehicle LP detector. To develop a background model by using a GMM is possible in the circumstance of a fixed camera and extracts the motions using background subtraction. Firstly, an adaptive GMM is used to find the region of interest (ROI) on which motion detectors are running to detect the vehicle area as blobs ROIs. Secondly, a cascade of boosted classifiers is executed on the blobs ROIs to detect a LP. The experimental results on our test video with the resolution of $720{\times}576$ show that the LPD rate of the proposed system is 99.14% and the average computational time is approximately 42ms.

• 한국정보통신학회논문지
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• 제16권7호
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• pp.1518-1523
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• 2012

영상매체가 여러 방면에서 발전함에 따라 영상처리의 중요성이 높아지고 있다. 영상처리 분야 중 에지검출은 물체 인식, 물체 분할, 의료 및 산업 전반적인 분야 등에서 많이 활용되고 있다. 에지는 영상에서 중요한 요소인 크기, 방향, 위치 등의 정보를 포함하고 있다. 에지를 검출하기 위한 기존의 방법에는 Sobel, Prewitt, Roberts, Laplacian 등의 방법이 있으며, 기존의 방법들은 AWGN(Additive White Gaussian Noise)에 훼손된 영상에서 에지검출 특성이 저하된다. 따라서 본 연구는 AWGN에 훼손된 영상에서 우수한 에지검출 특성을 갖는 변형된 가중치 벡터를 이용한 알고리즘을 제안하였다.

• 반도체디스플레이기술학회지
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• 제12권2호
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• pp.67-72
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• 2013

Temperature is a critical parameter in yield improvement for wafer manufacturing. In chemical vapor deposition (CVD) equipment, crack defect in ceramic heater leads to yield reduction, however, there is no suitable ceramic heater fault detection system for conventional CVD equipment. This paper proposes a short-time zero-crossing rate based fault detection method for the ceramic heater in CVD equipment. The proposed method measures the output signal ($V_{pp}$) of RF filter and extracts the zero-crossing rate (ZCR) as feature vector. The extracted feature vectors have a discriminant power and Gaussian mixture model (GMM) based fault detection method can detect fault in ceramic heater. Experimental results, carried out by measured signals provided by a CVD equipment manufacturer, indicate that the proposed method detects effectively faults in various process conditions.