• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.187-190
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• 2002

본 논문에서는 음성 신호에서 발성 화자가 바뀌는 시점을 자동적으로 찾아내는 화자변화 구간 검출에 대하여 연구하였다. 화자변화 검출을 위해서는 음성 신호에 나타나는 화자 개별성에 의한 차이만 비교해야 하는데 실제 환경에서는 화자들이 동일한 내용의 발성을 하지 않으므로 다른 발성내용에 의한 정보가 포함되어 검출 성능을 저하시킨다. 그러므로 각 화자의 개별특성만 강조되도록 발성내용에 포함된 음성학적 정보의 영향을 제거하는 방법을 통해 검출 성능을 향상시켰다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2015.07a
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• pp.297-298
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• 2015

본 연구에서는 기존 방식인 인력에 의한 송전 선로 점검 방식을 대체할 수 있는 로봇 기술이 적용된 열화 검출기의 제작을 위하여 송전 선로의 부식 메커니즘과 물성 변화에 대해 고찰하였다. 이를 통해 송전 선로의 열화에 의한 기계적 결함과 전기적 특성변화의 확인을 위한 과학적인 접근 방법을 제시하여 송전 선로의 열화를 포함한 외부 이상을 검출할 수 있는 열화 검출기에 대한 연구를 수행하였다.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2000.08a
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• pp.29-32
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• 2000

본 논문에서는 미지의 반송파주파수를 가진 협대역 신호의 존재를 광대역에서 검출하는 문제를 고려하였다. DFT 전력 스펙트럼을 평균화하여 주파수 영역에서 Neyman-Pearson criterion을 사용하여 신호를 검출하는 방법을 사용하였다. 평균화된 DFT 스펙트럼의 통계적 특성과 검출 threshold 및 검출 확률을 분석하여 보았다.

• Journal of the KSME
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• v.28 no.4
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• pp.343-348
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• 1988

몇 가지 균열검출법 및 크기의 측정법에 대하여 개요, 문제점, 정량적 측정에 유의해야 할 점을 살펴보았다. 아직 어느 방법도 모든 균열에 적용할 만큼 완전한 방법은 없지만 적용범위와 유 의사항을 이해하고 측정대상에 맞는 방법을 올바로 적용한다면 목적에 부합하는 결과를 얻을 것으로 본다. 기기나 구조물의 파괴원인을 정확히 규명하고 잔존수명을 정확히 예측하여 파괴를 방지하려면 재료의 강도특성이나 파괴역학적 해석법의 연구에 못지 않게 비파괴적 균열검출법과 정량적 측정법에 관한 연구도 깊이 이루어져야 하리라 믿는다. 그러나 아직 우리나라에서는 이 점에 미흡함이 많다. 더 나은 측정방법을 고안해 내고, 측정장치를 개발하여 균열에 대한 정보 의 정확성을 높여 구조물의 안전성 평가의 신뢰성을 향상시킬 수 있는 연구가 활발히 진행되 어야 할 것이다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.921-923
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• 2015

Edge in the image includes the size, direction and location of objects. The existing detection methods for detecting this edge is a method using Sobel, Prewitt, Roberts and Laplacian, etc. These existing methods use a fixed weighted mask in order to detect the edge and have somewhat insufficient edge detection characteristics. Therefore in this paper, an algorithm that detects the edge by applying the grey level converting function according to the pixel distribution of local mask was proposed.

• Journal of Broadcast Engineering
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• v.19 no.6
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• pp.896-906
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• 2014

In this paper, a real-time dual-mode temporal synchronization and compensation method based on a new reliability measure in stereoscopic video is proposed. The goal of temporal alignment is to detect the temporal asynchrony and recover synchronization of the two video streams. The accuracy of the temporal synchronization algorithm depends on the 3DTV contents. In order to compensate the temporal synchronization error, it is necessary to judge whether the result of the temporal synchronization is reliable or not. Based on our recently developed temporal synchronization method[1], we define a new reliability measure for the result of the temporal synchronization method. Furthermore, we developed a dual-mode temporal synchronization method, which uses a usual texture matching method and the temporal spatiogram method[1]. The new reliability measure is based on two distinctive features, a dynamic feature for scene change and a matching distinction feature. Various experimental results show the effectiveness of the proposed method. The proposed algorithms are evaluated and verified through an experimental system implemented for 3DTV.

• KIPS Transactions on Software and Data Engineering
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• v.11 no.1
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• pp.51-58
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• 2022

Drivable area detection, one of the main functions of advanced driver assistance systems, means detecting an area where a vehicle can safely drive. The drivable area detection is closely related to the safety of the driver and it requires high accuracy with real-time operation. To satisfy these conditions, V-disparity-based method is widely used to detect a drivable area by calculating the road disparity value in each row of an image. However, the V-disparity-based method can falsely detect a non-road area as a road when the disparity value is not accurate or the disparity value of the object is equal to the disparity value of the road. In a road environment including vegetation, such as a highway and a country road, the vegetation area may be falsely detected as the drivable area because the disparity characteristics of the vegetation are similar to those of the road. Therefore, this paper proposes a drivable area detection method and hardware architecture with a high accuracy in road environments including vegetation areas by reducing the number of false detections caused by V-disparity characteristic. When 289 images provided by KITTI road dataset are used to evaluate the road detection performance of the proposed method, it shows an accuracy of 90.12% and a recall of 97.96%. In addition, when the proposed hardware architecture is implemented on the FPGA platform, it uses 8925 slice registers and 7066 slice LUTs.

• Korean Journal of Optics and Photonics
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• v.15 no.4
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• pp.321-324
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• 2004

We have composed an experimental system using the superposition method to measure the nonlinearity of photodetectors for optical fiber power measurements. Also we have measured the nonlinearity of a high power detector and of a low power detector. The two detectors have shown good linearity within 0.01% and 0.02%, respectively, in the 50 ㏈ dynamic range. These detectors are used as reference detectors in optical fiber characteristics measurements.

• Journal of KIISE:Software and Applications
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• v.27 no.8
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• pp.864-876
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• 2000

This paper proposes a new scene boundary detection scheme for the MPEG System stream using MPEG Audio information and proves its usefulness by extensive experiments. A scene boundary has a characteristic that the audio as well as video information are changed rapidly. This paper first classifies this scene boundary into three cases ; Radical, Gradual, Micro Changes, with respect to the audio changes. The Radical change has a large-scale changing of decibel value and pitch value at a scene boundary, the Gradual change shows the long-time transition of decibel and pitch values from max to min or vice versa, and the Micro change displays a some change of pitch or frequency distribution without decibel changes. Upon this analysis, a new scene change detection algorithm detecting these three cases is proposed in which a progressive window with a time line is used to trace the changes in the audio information. Some experiments with various movies show that proposed algorithm could produce a high detection ratio for Radical change that is the most popular scene change in the movies, while producing a moderate detection ratio for Gradual and Micro changes. The proposed scene boundary detection scheme could be used to build a database for visual information like MPEG System stream.

• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.6
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• pp.417-424
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• 2010

This paper proposes a new islanding detection method for a grid-connected photovoltaic system. It is based on the fact that the equivalent harmonic components vary according to the grid connection status. The advantage of the proposed method is the reduced Non-Detection Zone and fast detection time. Also it can have the robust detection capability against grid disturbances. The theoretic analysis using grid-harmonic modeling is performed and verified by test result using 32-bit high performance DSP processor.