• International Journal of Fuzzy Logic and Intelligent Systems
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• 제16권2호
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• pp.131-139
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• 2016

Recognition of human motions has become a main area of computer vision due to its potential human-computer interface (HCI) and surveillance. Among those existing recognition techniques for human motions, head detection and tracking is basis for all human motion recognitions. Various approaches have been tried to detect and trace the position of human head in two-dimensional (2D) images precisely. However, it is still a challenging problem because the human appearance is too changeable by pose, and images are affected by illumination change. To enhance the performance of head detection and tracking, the real-time three-dimensional (3D) data acquisition sensors such as time-of-flight and Kinect depth sensor are recently used. In this paper, we propose an effective feature extraction method, called adaptive local binary pattern (ALBP), for depth image based applications. Contrasting to well-known conventional local binary pattern (LBP), the proposed ALBP cannot only extract shape information without texture in depth images, but also is invariant distance change in range images. We apply the proposed ALBP for head detection and tracking in depth images to show its effectiveness and its usefulness.

• 한국통신학회논문지
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• 제35권8C호
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• pp.661-666
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• 2010

본 논문에서는 비음수 행렬 인수분해 기법을 기반으로 한 새로운 음성 검출 (Voice Activity Detection, VAD) 알고리즘을 제안한다. 먼저, 기존의 통계모델기반의 음성검출기를 분석하고, 이를 기반으로 비음수 행렬 인수분해를 통해 도출한 입력 기초 벡터와 잡음 기초 벡터 차이로 음성의 유무를 판단한다. 이때 최적의 문턱값을 찾기 위해 통계모델 기반의 음성검출기에 의해 추정된 잡음 구간에서 NMF 결과의 분포에 따라 최적화된 문턱값을 비음수 행렬기반의 음성 검출 알고리즘에 적용하는 방법을 제안한다. 실험 결과 기존의 통계적 모델 기반의 음성검출기에 비해 6.75%의 성능향상을 가져왔다.

• 한국군사과학기술학회지
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• 제14권6호
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• pp.1097-1106
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• 2011

Tactical Information Communication Network(TICN), a concept-type integrated Military Communication system that enables precise command control and decision making, is designed to advance into high speed, large capacity, long distance wireless relay transmission. To support mobility in battlefield environments, the application of Ad-hoc networking technology to its wireless communication has been examined. Ad-hoc network works properly only if the participating nodes cooperate in routing and packet forwarding. However, if selfish nodes not forwarding packets of other nodes and malicious nodes making the false accusation are in the network, it is faced to many threats. Therefore, detection and management of these misbehaving nodes is necessary to make confident in Ad-hoc networks. To solve this problem, we propose an efficient intrusion detection technique to detect and manage those two types of attacks. The simulation-based performance analysis shows that our approach is highly effective and can reliably detect a multitude of misbehaving node.

• 천문학논총
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• 제21권2호
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• pp.87-94
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• 2006

The COREA (COsmic ray Research and Education Array in Korea) project aims to build a ground array of particle detectors distributed over Korean Peninsular, through collaborations of high school students, educators, and university researchers, in order to study the origin of ultra high energy cosmic rays. COREA array will consist of about 2000 detector stations covering several hundreds of $km^2$ area at its final configuration and detect electrons and muons in extensive air-showers triggered by high energy particles. During the intial phase COREA array will start with a small number of detector stations in Seoul area schools. In this paper, we have studied by Monte Carlo simulations how to select detector sites for optimal detection efficiency for proton triggered air-showers. We considered several model clusters with up to 30 detector stations and calculated the effective number of air-shower events that can be detected per year for each cluster. The greatest detection efficiency is achieved when the mean distance between detector stations of a cluster is comparable to the effective radius of the air-shower of a given proton energy. We find the detection efficiency of a cluster with randomly selected detector sites is comparable to that of clusters with uniform detector spacing. We also considered a hybrid cluster with 60 detector stations that combines a small cluster with ${\Delta}{\iota}{\approx}100m$ and a large cluster with ${Delta}{\iota}{\approx}1km$. We suggest that it can be an ideal configuration for the initial phase study of the COREA project, since it can measure the cosmic rays with a wide range energy, i.e., $10^{16}eV{\leq}E{\leq}10^{19}eV$, with a reasonable detection rate.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 춘계학술대회
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• pp.483-486
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• 2014

가시광통신(VLC: Visual Light Communication) 시스템은 조명에 통신을 융합하는 개념으로, 조명기능의 깜박임을 최소화(Flickerless)하고 통신기능의 데이터 송수신 거리를 최대화하는 것이 핵심 설계목표가 된다. 본 논문에서는 VLC 통신시스템의 수신된 신호에 포함된 노이즈를 감쇠시킴으로써 송신측에서 보낸 신호를 정확히 검출할 수 있는 방법을 제안하고 그 구현 결과를 제시하였다. 본 연구의 1,2차 구현을 통하여, 수신측에 설계한 특정주파수 대역의 LPF와 HPF를 단계별로 삽입함으로써 송신 데이터의 인식률이 높아졌고, 이러한 인식률 증대를 통하여 광도가 미약한 보다 먼 거리에서 데이터 수신이 가능함을 확인할 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권9호
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• pp.4467-4486
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• 2018

Trying to deal with the problem of low robustness of Copy-Move Forgery Detection (CMFD) under various transformation and degradation attacks, a novel CMFD method is proposed in this paper. The main advantages of proposed work include: (1) Discrete Analytical Fourier-Mellin Transform (DAFMT) and Locality Sensitive Hashing (LSH) are combined to extract the block features and detect the potential copy-move pairs; (2) The Euclidian distance is incorporated in the pixel variance to filter out the false potential copy-move pairs in the post-verification step. In addition to extracting the effective features of an image block, the DAMFT has the properties of rotation and scale invariance. Unlike the traditional lexicographic sorting method, LSH is robust to the degradations of Gaussian noise and JEPG compression. Because most of the false copy-move pairs locate closely to each other in the spatial domain or are in the homogeneous regions, the Euclidian distance and pixel variance are employed in the post-verification step. After evaluating the proposed method by the precision-recall-$F_1$ model quantitatively based on the Image Manipulation Dataset (IMD) and Copy-Move Hard Dataset (CMHD), our method outperforms Emam et al.'s and Li et al.'s works in the recall and $F_1$ aspects.

• 한국전자통신학회논문지
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• 제7권4호
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• pp.733-739
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• 2012

본 논문에서는 시간과 기후에 따라 변화하는 영상의 밝기와 색상 변화에도 강건한 연기검출 알고리즘을 제안한다. 제안하는 연기검출 알고리즘은 입력영상과 배경영상의 차영상을 이용하여 후보영역을 설정하고, 후보영역 차영상의 Gaussian 혼합모델 특징 계수를 비교하여 연기를 판별한다. 시간과 기후에 대응하기 위하여 입력영상의 평균 밝기와 색상을 기준으로 후보영역 설정을 위한 임계값을 4 단계로 구분한다. 후보영역에 대한 차영상의 Gaussian 혼합모델의 밝기 평균값을 기준으로 클러스터를 정렬하고, 클러스터 간의 Gaussian 혼합모델 특징 계수를 비교하여 연기를 판별한다. 제안하는 알고리즘을 미디어전용 DSP로 구현하고 야외에 설치된 카메라의 영상에 대하여 연기검출 실험을 통하여 효율적으로 연기를 검출할 수 있음 보인다.

• 제어로봇시스템학회논문지
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• 제12권2호
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• pp.119-129
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• 2006

Art psychotherapy is widely accepted as an effective tool for diagnosis and treatment of psychological disorders. Important factors for art psychotherapy diagnosis, based on the projection theory that the world of the inner mind appears in drawings, include main color and imbalance of a drawing. This paper develops a system for a machine to determine the main color and the imbalance of a drawing by color recognition and edge detection. Our proposed color recognition procedure adopts NBS(National Bureau of Standards) distance between colors in HVC(Hue, Value, Chroma) color space which is most similar to the human eye's color perception. Our edge detection procedure applies blurring, clustering and transformation to a standard color in a series. Our system considers the numbers of pixels and clusters for each color as a criterion for main color and the frequency of edge coordinates for each region for imbalance. The proposed machine procedure, verified through case studies, can help overcome the subjectivity, ambiguity and uncertainty in human decision involved in art psychotherapy.

• ETRI Journal
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• 제33권2호
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• pp.251-258
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• 2011

Applying face alignment after face detection exerts a heavy influence on face recognition. Many researchers have recently investigated face alignment using databases collected from images taken at close distances and with low magnification. However, in the cases of home-service robots, captured images generally are of low resolution and low quality. Therefore, previous face alignment research, such as eye detection, is not appropriate for robot environments. The main purpose of this paper is to provide a new and effective approach in the alignment of small and blurred faces. We propose a face alignment method using the confidence value of Real-AdaBoost with a modified census transform feature. We also evaluate the face recognition system to compare the proposed face alignment module with those of other systems. Experimental results show that the proposed method has a high recognition rate, higher than face alignment methods using a manually-marked eye position.

• 한국전산유체공학회지
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• 제22권1호
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• pp.37-42
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• 2017

Infrared signals are frequently used to detect objects exposed to wide variety of environmental conditions. Detection by infrared signature is accomplished by distinguishing objects by using the IR radiant contrast between objects and the background. There are several methods of estimating the IR radiant contrast. The inverse distance weighting method, which is one of the IR radiant contrast estimation method using the effect of distance from objects, is known to be an effective way to analyze radiant contrast for complex backgrounds. However this method has a disadvantage of requiring a long calculation time. In this study we propose a statistical method of estimating the IR radiant contrast by using randomly selected pixels of arbitrary number among background pixels to reduce calculation time. Some measured IR images in MWIR and LWIR regions are used to test the applicability of the method proposed and we found that the proposed method is very effective in determining the IR radiant contrast showing very rapid estimation with minar accuracy loss.