• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 추계학술대회
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• pp.711-714
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• 2015

영상 복원을 위해서 에지(edge) 검출 알고리즘을 갖는 가중 격자형 메디안필터(median filter)를 사용한 새로운 방법을 제안하였다. 에지를 검출하기 위한 시험들로 구성되어 있으며 격자형 창을 사용하였다. 잡음에 의해서 손상된 영상에 제안한 방법을 적용 하였으며 그 결과를 일반 메디안 필터와 격자형 메디안 필터의 결과들과 비교 하였다. 에지 검출 알고리즘을 갖는 가중격자형 메디안 필터를 사용하는 것이 다른 메디안 필터를 사용한 결과보다 매우 우수한 성능을 가짐을 확인하였다.

• 로봇학회논문지
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• 제17권2호
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• pp.172-177
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• 2022

In general, detection robots using ultrasonic sensors are equipped with sensors to protrude outward or to contact objects. However, in the case of a screw-propelled robot that detects the inside of a reactor tendon duct, if the ultrasonic sensor protrudes to the outside, resistance due to grease is generated, and thus the propulsion efficiency is reduced. In order to increase the propulsion efficiency, the screw must be sharp, and the sharper the screw, the more difficult it is to apply a high-performance ultrasonic sensor, and the detection efficiency decreases. This paper proposes a screw shape-changing mechanism that can improve both propulsion efficiency and detection efficiency. This mechanism includes an overlapped helical ring (OHR) structure and a magnetic clutch system (MCS), and thus the shape of a screw may be changed to a compact size. As a result, the Screw-propelled robot with this mechanism can reduce the overall length by about 150 mm and change the shape of the screw faster and more accurately than a robot with a linear actuator.

• Nuclear Engineering and Technology
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• 제55권11호
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• pp.3925-3934
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• 2023

The importance of fast neutron detection for nuclear safeguards purposes has increased due to its potential advantages such as reasonable cost and higher precision for larger sample masses of nuclear materials. Pulse-shape discrimination (PSD) is inevitably used to discriminate neutron- and gamma-ray- induced signals from organic scintillators of very high gamma sensitivity. The light output (LO) threshold corresponding to several MeV of recoiled proton energy could be necessary to achieve fine PSD performance. However, this leads to neutron count losses and possible distortion of results obtained by neutron multiplicity counting (NMC)-based nuclear material accountancy (NMA). Moreover, conventional PSD techniques are not effective for counting of neutrons in a high-gamma-ray environment, even under a sufficiently high LO threshold. In the present work, PSD performance (figure-of-merit, FOM) according to LO bands was confirmed using a conventional charge comparison method (CCM) and compared with results obtained by convolution neural network (CNN)-based PSD algorithms. Also, it was attempted, for the first time ever, to reject fake neutron signals from distorted PSD regions where neutron-induced signals are normally detected. The overall results indicated that higher neutron detection efficiency with better accuracy could be achieved via CNN-based PSD algorithms.

• Journal of Veterinary Science
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• 제23권4호
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• pp.51.1-51.10
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• 2022

Background: Due to the unavailability of an effective vaccine or antiviral drug against the African swine fever virus (ASFV), rapid diagnosis methods are needed to prevent highly contagious African swine fever. Objectives: The objective of this study was to establish the ladder-shape melting temperature isothermal amplification (LMTIA) assay for the detection of ASFV. Methods: LMTIA primers were designed with the p72 gene of ASFV as the target, and plasmid pUC57 was used to clone the gene. The LMTIA reaction system was optimized with the plasmid as the positive control, and the performance of the LMTIA assay was compared with that of the commercial real-time polymerase chain reaction (PCR) kit in terms of sensitivity and detection rate using 200 serum samples. Results: Our results showed that the LMTIA assay could detect the 10⁴ dilution of DNA extracted from the positive reference serum sample, which was the same as that of the commercial real-time PCR kit. The coincidence rate between the two assays was 100%. Conclusions: The LMTIA assay had high sensitivity, good detection, and simple operation. Thus, it is suitable for facilitating preliminary and cost-effective surveillance for the prevention and control of ASFV.

• 전기전자학회논문지
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• 제24권4호
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• pp.1148-1155
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• 2020

Fire must be extinguished as quickly as possible because they cause a lot of economic loss and take away precious human lives. Especially, the detection of smoke, which tends to be found first in fire, is of great importance. Smoke detection based on image has many difficulties in algorithm research due to the irregular shape of smoke. In this study, we introduce a new real-time smoke detection algorithm that reduces the detection of false positives generated by irregular smoke shape based on faster r-cnn of factory-installed surveillance cameras. First, we compute the global frame similarity and mean squared error (MSE) to detect the movement of smoke from the input surveillance camera. Second, we use deep learning algorithm (Faster r-cnn) to extract deferred candidate regions. Third, the extracted candidate areas for acting are finally determined using space and temporal features as smoke area. In this study, we proposed a new algorithm using the space and temporal features of global and local frames, which are well-proposed object information, to reduce false positives based on deep learning techniques. The experimental results confirmed that the proposed algorithm has excellent performance by reducing false positives of about 99.0% while maintaining smoke detection performance.

• 한국구조물진단유지관리공학회 논문집
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• 제17권1호
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• pp.124-132
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• 2013

손상된 구조물의 동적응답신호를 역해석함으로써 손상위치와 정도를 파악할 수 있다. 일반적으로 손상 전 후 고유진동수의 변화로부터 강성의 감소량을 구하고, 모드형상의 변화로부터 손상위치를 파악할 수 있다. 토목구조물의 경우 동적 응답신호로부터 손상을 검출코자 하는 연구가 상당히 진행되었으며 실용화 되었다. 그러나 건축구조물의 경우 몇 가지 문제로 인하여 이에 대한 연구가 활발히 진행되지 못하고 있다. 본 연구에서는 모드형상을 이용한 전단형 건물의 손상위치 추적방안을 제시 하고자 한다. 전단형 건물의 손상 전 후 1차 모드강성의 차이를 이용한 손상위치 추적지수를 이론적으로 고찰하였으며, 이를 Matlab 또는 MIDAS GENw와 같은 수치해석모델에 적용함으로써 손상위치추적기법의 타당성을 검증하였다. 또한 소형 진동대 실험을 수행하고 실측된 동적응답신호를 이용하여 손상위치를 추적함으로써 실구조물에 대한 적용성을 검토하였다. 진동대 실험결과 층강성이 25% 감소할 때 1차 모드 진동수는 12%증가 하였으며, 손상위치 지수는 손상 층에서 마이너스 값을 나타내었다.

• 한국CDE학회논문집
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• 제18권2호
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• pp.113-119
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• 2013

This paper proposes an approach to detect unintended deflections in an automotive outer panel. Conventionally, the detection of unintended deflections has been performed by experienced works, and it requires much amount of time and efforts. The motivation of this work is to reduce such efforts by providing an automated detection methodology. For the detection of unintended deflections, we make use of the measured data from an optical scanner which can be considered as a Z-map data. The proposed approach consists of four major steps; 1) measured data acquisition for an automotive outer panel, 2) identification of shape features, 3) removal of shape features, and 4) detection of unintended deflections via curvature analysis.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 춘계학술대회 논문집
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• pp.7-14
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• 2006

Detection and identification of targets from remotely sensed imagery are of great interest for civilian and military application. This paper presents an algorithm for target detection in high spatial resolution imagery based on the spectral and the dimensional characteristics of the reference target. In this algorithm, the spectral and the dimensional information of the reference target is extracted automatically from the sample image of the reference target. Then in the entire image, the candidate target pixels are extracted based on the spectral characteristics of the reference target. Finally, groups of candidate pixels which form isolated spatial objects of similar size to that of the reference target are extracted as detected targets. The experimental test results showed that even though the algorithm detected spatial objects which has different shape as targets if the spectral and the dimensional characteristics are similar to that of the reference target, it could detect 97.5% of the targets in the image. Using hyperspectral image and utilizing the shape information are expected to increase the performance of the proposed algorithm.

• 한국통신학회논문지
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• 제12권4호
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• pp.405-413
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• 1987

본 논문은 2-차원에서 3가지 형태(Square, Cross, X-shape)의 메디안 필터를 사용하여 레이다 영상의 원영상을 유지하면서 잡음을 제거하여 영상을 개선하고, 연산자를 적용하여 경계를 검출한다. 레이다 영상의 특성에서 곡선 부분이 많으므로 제안된 경계 검출 연산자에 의한 결과와 기존의 경계검출 방법인 Sobel, Prewitt, Robert, Laplacian. Kirsch의 결과를 비교한다.

• 방송공학회논문지
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• 제13권5호
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• pp.681-684
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• 2008

We proposed a method to improve moving object detection capability of Gaussian Mixture Model by suggesting shape adaptive bidirectional block matching algorithm. This method achieves more accurate detection and tracking performance at various motion types such as slow, fast, and bimodal motions than that of Gaussian Mixture Model. Experimental results showed that the proposed method outperformed the conventional methods.