• Journal of applied mathematics & informatics
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• 제27권1_2호
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• pp.195-203
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• 2009

In this paper, a necessary and sufficient condition for lattice sampling theorem to hold for frame in subspaces of $L^2$(R) is established. In addition, we obtain the formula of lattice sampling function in frequency space. Furthermore, by discussing the parameters in Theorem 3.1, some corresponding corollaries are derived.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.605-608
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• 1999

In this paper, we proposed several scene analysis algorithms. These algorithms using image difference and histogram operate on the sequence of DC coefficient which is extracted from Motion JPEG or MPEG without full-frame decompression. Since DC sequence has the most information of full frame while it has reduced data. Experimental results show less than 1/64 of full frame analysing complexity and exactly analyze scene changes and extract key frames.

• 한국정보전자통신기술학회논문지
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• 제2권1호
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• pp.43-50
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• 2009

This paper caters the need of acquiring the principal objects, characters, and scenes from a video in order to entertain the image based query. The movie frames are divided into frames with 2D representative images called "key frames". Various regions in a key frame are marked as key objects according to their textures and shapes. These key objects serve as a catalogue of regions to be searched and matched from rest of the movie, using viewpoint invariant regions calculation, providing the location, size, and orientation of all the objects occurring in the movie in the form of a set of structures collaborating as video profile. The profile provides information about occurrences of every single key object from every frame of the movie it exists in. This information can further ease streaming of objects over various network-based viewing qualities. Hence, the method provides an effective reduced profiling approach of automatic logging and viewing information through query by example (QBE) procedure, and deals with video streaming issues at the same time.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권9호
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• pp.3357-3376
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• 2015

Wireless sensor network is an important research topic that has attracted a lot of attention in recent years. However, most of the interest has focused on wireless sensor network to gather scalar data such as temperature, humidity and vibration. Scalar data are insufficient for diverse applications such as video surveillance, target recognition and traffic monitoring. However, if we use camera sensors in wireless sensor network to collect video data which are vast in information, they can provide important visual information. Video sensor networks continue to gain interest due to their ability to collect video information for a wide range of applications in the past few years. However, how to efficiently store the massive data that reflect environmental state of different times in video sensor network and how to quickly search interested information from them are challenging issues in current research, especially when the sensor network environment is complicated. Therefore, in this paper, we propose a fast algorithm for extracting key frames from video and describe the design and implementation of key frame extraction and sharing in Android for wireless video sensor network.

• Journal of Information Processing Systems
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• 제7권1호
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• pp.103-110
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• 2011

In this paper, an adaptive motion vector smoothing scheme based on weighted vector median filtering is proposed in order to eliminate the motion outliers more effectively for improving the quality of side information in frame-based distributed video coding. We use a simple motion vector outlier reliability measure for each block in a motion compensated interpolated frame and apply weighted vector median filtering only to the blocks with unreliable motion vectors. Simulation results show that the proposed adaptive motion vector smoothing algorithm improves the quality of the side information significantly while maintaining low complexity at the encoder in frame-based distributed video coding.

• 한국통신학회논문지
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• 제23권7호
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• pp.1744-1754
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• 1998

본 논문에서는 무선 네트워크의 이동단말과 유선망의 고정호스트 사이에 효율적인 데이타 서비스를 제공하는 데이타 서비스 프로토콜에 대해 연구하였다 무선 링크는 유선 링크에 비해 높은 비트 에러율을 가지며, 이로 인해 유무선 연동환경에서는 데이타 서비스를 제공하는 TCP의 성능이 감소된다. 따라서 이러한 성능감소를 중이기 위해 유선과 무선이 연결되는 부분에 간단한 프로토콜 처리기를 가지는 연동모듈을 제안하였다. 제안된 연동모듈은 TCP 프레임의 헤더정보를 분석하고, 수신된 TCP 프레임이 중복된 프레임일 경우, 이를 폐기하며, 재전송 요구를 받을 경우 재전송 절차를 수행하게 된다. 시뮬레이션을 통해 그 성능을 분석한 결과 유무선 연동환경에서 기존의 IWF를 사용하였을 때 보다 제안된 IWF를 사용하는 것이 지연과 처리율 측면에서 우수한 성능을 보였다.

• 한국산업정보학회논문지
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• 제10권1호
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• pp.49-57
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• 2005

ATM 포럼은 ATM 네트워크에서 TCP 트래픽에게 MCR을 보장하고, 여분의 대역폭을 공정하게 공유할 수 있도록 GFR 서비스를 정의하였다 GFR 스위치 구현 방법은 F-GCRA 알고리즘과 프레임 전달 메커니즘으로 이루어진다. F-GCRA 알고리즘은 MCR 보장에 적합한 프레임을 분류한다. 프레임 전달 메커니즘은 F-GCRA의 분류 정보에 따라 프레임 단위로 셀을 저장하고, 스케줄링 기법에 따라 출력 단자로 저장된 셀을 전달한다 전역 임계값을 갖는 공유 버퍼로 이루어진 단순 GFR 메커니즘은 단순한 구조로 인해 구현이 용이 하지만, MCR를 보장하는데 충분치 않다고 알려져 있다 본 논문은 단순 GFR 메커니즘을 갖는 ATM 스위치에서 TCP 트래픽을 위한 GFR 서비스 성능을 평가한다.

• Journal of the Optical Society of Korea
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• 제20권6호
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• pp.678-685
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• 2016

The standard high-availability seamless redundancy (HSR) protocol utilizes duplicated frame copies of each sent frame for zero fail over time. This means that even in cases of a node or link failure, the destination node will receive at least one copy of the sent frame, resulting in no network downtime. However, the standard HSR is mostly based on the electrical signal connection inside the node, which leads to the production of considerable latency at each node due to frame processing. Therefore, in a large scale HSR ring network, the accumulated latencies become significant and can often restrict the mission-critical real-time application of HSR. In this paper, we present a novel design for optical HSR (OHSR) that uses beam splitting/combining techniques. The proposed OHSR passes the frames directly to adjacent nodes without frame processing at each node, thereby theoretically generating no latency in any node. Various simulations for network samples, made to validate the OHSR design and its performance, show that the OHSR outperforms the standard HSR.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(4)
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• pp.25-28
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• 2002

This paper presents variable bit rate(VBR) rate control scheme based on MPEG-4 VM8 rate control scheme. An initial Q searching method provides more accurate bit allocation for the first frame. A frame skipping and RD Model update scheme when coded frame quality is too low or high prevents image quality fluctuation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권11호
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• pp.5459-5473
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• 2017

Recently, a tracking algorithm called the spatial-temporal context model has been proposed to locate a target by using the contextual information around the target. This model has achieved excellent results when the target undergoes slight occlusion and appearance changes. However, the target location in the current frame is based on the location in the previous frame, which will lead to failure in the presence of fast motion because of the lack of a prediction mechanism. In addition, the spatial context model is updated frame by frame, which will undoubtedly result in drift once the target is occluded continuously. This paper proposes two improvements to solve the above two problems: First, four possible positions of the target in the current frame are predicted based on the displacement between the previous two frames, and then, we calculate four confidence maps at these four positions; the target position is located at the position that corresponds to the maximum value. Second, we propose a target reliability criterion and design an adaptive threshold to regulate the updating speed of the model. Specifically, we stop updating the model when the reliability is lower than the threshold. Experimental results show that the proposed algorithm achieves better tracking results than traditional STC and other algorithms.