• Journal of Advanced Navigation Technology
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• v.22 no.1
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• pp.20-26
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• 2018

In this paper, we propose a moving object detection and tracking algorithm based on multi-frame feature point tracking information to reduce false positives. However, there are problems of detection error and tracking speed in existing studies. In order to compensate for this, we first calculate the corner feature points and the optical flow of multiple frames for camera movement compensation and object tracking. Next, the tracking error of the optical flow is reduced by the multi-frame forward-backward tracking, and the traced feature points are divided into the background and the moving object candidate based on homography and RANSAC algorithm for camera movement compensation. Among the transformed corner feature points, the outlier points removed by the RANSAC are clustered and the outlier cluster of a certain size is classified as the moving object candidate. Objects classified as moving object candidates are tracked according to label tracking based data association analysis. In this paper, we prove that the proposed algorithm improves both precision and recall compared with existing algorithms by using quadrotor image - based detection and tracking performance experiments.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.6
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• pp.257-262
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• 2010

In this paper, we propose an effective method for detecting signals among multi-user in cooperative communication system. Spread sequence is inserted to NULL space of synchronization channel to synchronize between each user among frame formats of the cooperative communication and then transmitted. In the receiver, the wanted signal is detected by using correlation among the inserted spread sequences. As simulation results, correlations among the signals using m-sequence in AWGN, Rician, and Rayleigh channel are shown. Using the simulation results in this paper, we expect a reliable cooperative communication.

• Journal of Satellite, Information and Communications
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• v.5 no.1
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• pp.22-26
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• 2010

In this paper, we propose an effective method for detecting signals among multi-user in cooperative communication system. Spread sequence is inserted to NULL space of synchronization channel to synchronize between each user among frame formats of the cooperative communication and then transmitted. In the receiver, the wanted signal is detected by using correlation among the inserted spread sequences. As simulation results, correlations among the signals using Kasami/Walsh sequence in AWGN, Rician, and Rayleigh channel are shown. Using the simulation results in this paper, we expect a reliable cooperative communication.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.3
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• pp.78-87
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• 2002

A macroblock(MB) in MPEG coded domain can have zero, one, or two motion vectors depending on its frame type and prediction direction (forward-, backward-, or hi-directionally). In this paper, we propose a method that converts these motion vectors on MPEG coded domain as a uniform set, independent of the frame type and the direction of prediction, and directly utilizes these re-analyzed motion vectors for understanding video contents. Also, using this frame-type-independent motion vector, we propose novel methods for detecting and tracking moving objects with frame-based detection accuracy on the compressed domain. These algorithms are performed directly from the MPEG bitstreams after VLC decoding with little time consumption. Experimental results show validity and outstanding performance of our methods.

• Journal of Korea Multimedia Society
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• v.20 no.2
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• pp.196-204
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• 2017

Behavior of intelligent video surveillance system is recognized by analyzing the pattern of the object of interest by using the frame information of video inputted from the camera and analyzes the behavior. Detection of object's certain behaviors in the crowd has become a critical problem because in the event of terror strikes. Recognition of object's certain behaviors is an important but difficult problem in the area of computer vision. As the realization of big data utilizing machine learning, data mining techniques, the amount of video through the CCTV, Smart-phone and Drone's video has increased dramatically. In this paper, we propose a multiple-sliding window method to recognize the cumulative change as one piece in order to improve the accuracy of the recognition. The experimental results demonstrated the method was robust and efficient learning units in the classification of certain behaviors.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.11a
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• pp.224-229
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• 1999

In the field of speech recognition, the research area can be classified into the following two categories: one which is concerned with the development of phoneme-level recognition system, the other with the efficiency of word-level recognition system. The resonable phoneme-level recognition system should detect the phonemic boundaries appropriately and have the improved recognition abilities all the more. The traditional LPC methods detect the phoneme boundaries using Itakura-Saito method which measures the distance between LPC of the standard phoneme data and that of the target speech frame. The MFCC methods which treat spectral transitions as the phonemic boundaries show the lack of adaptability. In this paper, we present new speech recognition system which uses auto-correlation method in the phonemic boundary detection process and the multi-layered Feed-Forward neural network in the recognition process respectively. The proposed system outperforms the traditional methods in the sense of adaptability and another advantage of the proposed system is that feature-extraction part is independent of the recognition process. The results show that frame-unit phonemic recognition system should be possibly implemented.

• Science of Emotion and Sensibility
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• v.20 no.2
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• pp.137-148
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• 2017

The present study examined the effect of stimulus contrast and color on detection of a target embedded in streams of letters. In Experiment 1, each trial displayed four rapid serial visual presentation (RSVP) streams of letters (i.e., multi-RSVP), and each stream occupied one of four different locations. Each frame in the RSVP stream had four white distractors at the locations except one frame where a dim grey target was displayed at a location with three white distractors at the remaining locations. In the low-visibility target condition, the target's grey color was slightly darker than the background grey whereas much dimmer in the high-visibility condition. Participants were asked to report presence of a predesignated target as quickly and accurately as possible upon its detection in each trial, and their target detection turned out more accurate and quicker in the high-visibility than the low-visibility condition. In Experiment 2, the same RSVP displays and task as Experiment were used, but the grey target letters in the high-visibility condition were replaced with those of distinct chromatic colors. Participants detected target presence more accurately in the high-visibility condition, but the reaction time did not differ between the visibility conditions. The results indicate that higher stimulus contrast as well as distinct color can improve perception of a target stimulus displayed among visually-demanding background, but also suggest that stimulus contrast may play a more substantial role for such perceptual improvement.

• Korean Journal of Remote Sensing
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• v.20 no.2
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• pp.125-137
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• 2004

In case of using image sequence taken from a moving camera along a road in an urban area, general video mosaicing technique based on a single baseline cannot create 2-D image mosaics. To solve the drawback, this paper proposed a new image mosaicing technique through 3-D multi-baselines that can create image mosaics in 3-D space. The core of the proposed method is that each image frame has a dependent baseline, an equation of first order, calculated by using ground control point (GCP) of optical flows. The proposed algorithm consists of 4 steps: calculation of optical flows using hierarchical strategy, calculation of camera exterior orientation, determination of multi-baselines, and seamless image mosaics. This paper realized and showed the proposed algorithm that can create efficient image mosaics in 3-D space from real image sequence.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.6
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• pp.740-747
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• 2012

An Active Electronically Scanned Array(AESA) radar required necessarily as the Fire Control Radar(FCR) of recent fighters has ununiform detection range with regard to scan angle due to scan loss. Although the compensation method of scan loss in an AESA radar with variable dwell time is investigated, the effectiveness of the method in a fighter FCR with multi-function such as search, track, and missile guidance within limited resources should be considered systematically. In this paper, uniform search performance of an AESA radar using variable dwell time with regard to scan angle is derived. We assumed the search load of 50 % for case without changing dwell time in fixed frame time and showed the fighter FCR requirement for multi-function is not satisfied because the search load for the uniform search performance should be increased by about 100 %. On the other hand, in case of increasing the frame time for the uniform search performance and search load of 50 %, degradation of the search performance is shown by 86.7 % compared with the former. Based on these analyses, the effective beam operation strategy on an airborne AESA radar with uniform search performance in whole scan area is described with consideration of frame time, search load and performance as a whole.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.498-500
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• 2022

공공 안전을 위한 영상 감시 시스템이 증가함에 따라 CCTV 관제사가 관제해야 할 영상의 수가 증가하고 있다. 점점 증가하는 관제 영상 수로 인해 CCTV 관제사는 수많은 영상 사이에서 발생하는 살인, 강도, 폭력 등 위급한 이상 상황을 놓치는 문제가 발생할 수 있다. 이러한 문제를 해결하기 위해 최근에는 영상에서 발생하는 이상 상황을 자동으로 탐지하고 CCTV 관제사에게 알려 관제 효율을 향상시키는 연구가 진행되고 있다. 본 논문은 영상에서 발생하는 이상 상황을 자동으로 탐지하기 위해 예측 기반 이상 탐지 방법에 다중 프레임 예측 에러를 활용해서 영상 이상 탐지 정확도를 향상시키는 방법을 제안한다. 결과적으로 제안한 방법을 사용함으로써 프레임 레벨 AUC가 Ped2 데이터 셋에서 92.70%에서 94.56%, Avenue 데이터셋에서 87.37%에서 89.17%로 상승하였다.