• 한국음향학회지
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• 제38권5호
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• pp.543-548
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• 2019

수중 표적의 기어박스 및 보조 장치 등으로부터 방사되는 토널 신호의 주파수 성분은 처리하고자 하는 주파수 대역에 비해 상대적으로 적어 희소신호로 모델링될 수 있다. 근래에 토널 신호의 주파수 희소성을 이용하여 빠른 시간 내에 적은 수의 관측치로 토널 주파수를 복원하는 압축센싱 기반의 연구가 활발히 진행되고 있다. 기존의 방법들은 이산(discrete) 주파수 영역에서 주파수를 검출하기 때문에 이산화로 인한 basis mismatch error가 불가피하다. 본 논문에서는 atomic norm minimization을 이용하여 적은 수의 관측치로 연속(continuous) 주파수 영역에서 토널 주파수를 검출하는 기법을 제안한다. 모의실험을 통해 기존의 기법들에 비해 제안하는 기법의 성능이 정확성과 평균제곱오차 측면에서 우수함을 확인하였다.

• 반도체디스플레이기술학회지
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• 제22권2호
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• pp.81-86
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• 2023

Recently, there has been an increased demand for light-emitting diode (LED) due to the growing emphasis on environmental protection. However, the use of GaN-based sapphire in LED manufacturing leads to the generation of defects, such as dislocations caused by lattice mismatch, which ultimately reduces the luminous efficiency of LEDs. Moreover, most inspections for LED semiconductors focus on evaluating the luminous efficiency after packaging. To address these challenges, this paper aims to detect defects at the wafer stage, which could potentially improve the manufacturing process and reduce costs. To achieve this, image processing and deep learning-based defect detection techniques for Sapphire Epi-Wafer used in Green LED manufacturing were developed and compared. Through performance evaluation of each algorithm, it was found that the deep learning approach outperformed the image processing approach in terms of detection accuracy and efficiency.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2008년도 춘계학술발표대회
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• pp.92-94
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• 2008

In this paper we describe an approach for template based detection and tracking of objects by chamfer matching in real time video. Detecting and tracking of any objects is the key problem in computer vision. In our case we try for hand and head of human for detection and tracking by chamfer matching technique. Matching involves correlating the templates with the distance transformed scene and determining the locations where the mismatch is below a certain user defined threshold.

• Asian-Australasian Journal of Animal Sciences
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• 제33권10호
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• pp.1683-1690
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• 2020

Objective: The rapid and reliable detection of the African swine fever virus (ASFV) plays an important role in emergency control and preventive measures of ASF. Some methods have been recommended by FAO/OIE to detect ASFV in clinical samples, including realtime polymerase chain reaction (PCR). However, mismatches in primer and probe binding regions may cause a false-negative result. Here, a slight modification in probe sequence has been conducted to improve the qualification of real-time PCR based on World Organization for Animal Health (OIE) protocol for accurate detection of ASFV in field samples in Vietnam. Methods: Seven positive confirmed samples (four samples have no mismatch, and three samples contained one mutation in probe binding sites) were used to establish novel real-time PCR with slightly modified probe (Y = C or T) in comparison with original probe recommended by OIE. Results: Both real-time PCRs using the OIE-recommended probe and novel modified probe can detect ASFV in clinical samples without mismatch in probe binding site. A high correlation of cycle quantification (Cq) values was observed in which Cq values obtained from both probes arranged from 22 to 25, suggesting that modified probe sequence does not impede the qualification of real-time PCR to detect ASFV in clinical samples. However, the samples with one mutation in probe binding sites were ASFV negative with OIE recommended probe but positive with our modified probe (Cq value ranked between 33.12-35.78). Conclusion: We demonstrated for the first time that a mismatch in probe binding regions caused a false negative result by OIE recommended real-time PCR, and a slightly modified probe is required to enhance the sensitivity and obtain an ASF accurate diagnosis in field samples in Vietnam.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2013년도 추계학술대회
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• pp.165-168
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• 2013

Image distortions, such as quantization errors, can have a severe negative impact on the performance of computer vision algorithms, and, more specifically, on object detection algorithms. State-of-the-art implementations of the JPEG-2000 image coder commonly allocate the available bits to minimize the Mean-Squared-Error (MSE) distortion between the original image and the resulting compressed image. However, considering that some state-of-the-art object detection methods use the gradient information as the main image feature, an improved object detection performance is expected for JPEG-2000 image coders that allocate the available bits to minimize the distortions on the gradient content. Accordingly, in this work, the Gradient Mean-Squared-Error (GMSE) based JPEG-2000 coder presents an improved object detection performance over the MSE based JPEG-2000 image coder when the object of interest is located at the same spatial location of the image regions with the strongest gradients and also for high bit-rates. For low bit-rates (e.g. 0.07bpp), the GMSE based JPEG-2000 image coder becomes overly selective in choosing the gradients to preserve, and, as a result, there is a greater chance of mismatch between the spatial locations of the gradients that the coder is trying to preserve and the spatial locations of the objects of interest.

• 한국전자파학회논문지
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• 제28권5호
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• pp.419-425
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• 2017

본 논문에서는 초고속 이동체 탐지에 적합한 상보형 금속산화 반도체(CMOS) 초광대역(UWB) RFIC 기반의 레이다 시스템을 제안한다. 시스템의 거리 분해능은 15 cm이고, 탐지 범위는 15 m에 이른다. 시스템 구현을 위해서 단일 칩 CMOS UWB IC를 설계, 구현한다. 포락선 검출과 등가 시간 샘플링 구조를 이용하여 측정 및 신호처리 시간을 대폭 단축한다. 측정을 통해서 UWB 펄스의 대역폭은 0.5~1.0 GHz이며, 중심주파수는 3.5~4.5 GHz 임을 보인다. 또한 15 m 범위의 신호 수신을 포함하여 대상체 거리값 출력까지의 신호처리 시간은 $150{\mu}sec$임을 보인다.

• 음성과학
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• 제15권2호
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• pp.67-77
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• 2008

In this paper, we implemented a robust speech recognizer using the TMS320VC33 DSP. For this implementation, we had built speech and noise database suitable for the recognizer using spectral subtraction method for noise removal. The recognizer has an explicit structure in aspect that a speech signal is enhanced through spectral subtraction before endpoints detection and feature extraction. This helps make the operation of the recognizer clear and build HMM models which give minimum model-mismatch. Since the recognizer was developed for the purpose of controlling car facilities and voice dialing, it has two recognition engines, speaker independent one for controlling car facilities and speaker dependent one for voice dialing. We adopted a conventional DTW algorithm for the latter and a continuous HMM for the former. Though various off-line recognition test, we made a selection of optimal conditions of several recognition parameters for a resource-limited embedded recognizer, which led to HMM models of the three mixtures per state. The car noise added speech database is enhanced using spectral subtraction before HMM parameter estimation for reducing model-mismatch caused by nonlinear distortion from spectral subtraction. The hardware module developed includes a microcontroller for host interface which processes the protocol between the DSP and a host.

• Journal of Power Electronics
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• 제17권5호
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• pp.1327-1337
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• 2017

Photovoltaic (PV) systems are influenced by disproportionate impacts on energy production caused by frequent mismatch cases. The occurrence of multiple maximum power points (MPPs) adds complexity to the tracking process in various PV systems. However, current maximum-power point tracking (MPPT) techniques exhibit limited performance. This paper introduces an enhanced simulated annealing (ESA)-based GMPPT technique against multiple MPP issues in P-V curve with different PV system structures. The proposed technique not only distinguishes global and local MPPs but also performs rapid convergence speed and high tracking accuracy of irradiance changing and restart capability detection. Moreover, the proposed global maximum power tracking algorithm can be applied in the central converter of DMPPT and hybrid PV system to meet various application scenarios. Its effectiveness is verified by simulation and test results.

• 생명과학회지
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• 제12권2호
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• pp.208-212
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• 2002

온도 기울기 전기영동장치를 이용하여 d(CXG)와 d(GXC) 염기의 열 안정성을 결정하는데 사람의 $\varepsilon$-글로빈 DNA조각을 사용하였다. 염기 쌍의 안정성은 이웃하는 염기서열에 의한 수소결합과 base stocking 상호작용에 의존한다. 염기 쌍의 안정성은 d(CXG) d(CYG)의 경우에 T.AG.A = A.G>C.T>T.C>C.A>A.C이다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제33권12호
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• pp.1090-1102
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• 2006

본 논문에서는 대학생들의 프로그래밍 과제물이나 프로그래밍 경진대회에 제출된 프로그램과 같이 동일한 기능을 요구받는 프로그램 소스 집합들에서 표절행위가 있었는지를 탐색하는 새로운 알고리즘을 제시하고 있다. 지금까지 보편적으로 사용되어 온 대표적인 알고리즘은 부분 스트링간의 완전 일치를 통한 Greedy-String-Tiling이나 두 스트링간의 지역정렬(local alignment)을 이용한 유사도 분석이 주된 방법론이었다. 본 논문에서는 해당 프로그램 소스의 집합에서 추출된 키워드들의 빈도수에 기반한 로그 확률값을 가중치로 하는 적응적(adaptive) 유사도 행렬을 만들어 이를 기반으로 주어진 프로그램의 유사구간을 탐색하는 새로운 방법을 소개한다. 우리는 10여개 이상의 프로그래밍 대회에서 제출된 실제 프로그램으로 본 방법론을 실험해 보았다. 실험결과 이 방법은 이전의 고정적 유사도 행렬(match이면 +1, mismatch이면 -1, gap이면 -2)에 의한 유사구간 탐색에 비하여 여러 장점이 있음을 알 수 있었으며, 제시한 적응적 유사도 행렬을 보다 다양한 표절탐색 목적으로 사용할 수 있음을 알 수 있었다.