• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.4C
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• pp.388-396
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• 2009

This paper proposes a new fire-smoke detection method by using extracted features from camera images and pattern recognition technique. First, moving regions are detected by analyzing the frame difference between two consecutive images and generate candidate smoke regions by applying smoke color model. A smoke region generally has a few characteristics such as similar color, simple texture and upward motion. From these characteristics, we extract brightness, wavelet high frequency and motion vector as features. Also probability density functions of three features are generated using training data. Probabilistic models of smoke region are then applied to observation nodes of our proposed Dynamic Bayesian Networks (DBN) for considering time continuity. The proposed algorithm was successfully applied to various fire-smoke tasks not only forest smokes but also real-world smokes and showed better detection performance than previous method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.9C
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• pp.761-770
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• 2010

In this paper, we propose a new Frame Rate Up-Conversion (FRUC) scheme to increase the frame rate from a lower number into a higher one and enhance the decoded video quality at the decoder. The proposed algorithm utilizes the preliminary frames of forward and backward direction using bilateral prediction. In the process of the preliminary frames, an additional interpolation is performed for the occlusion area because if the calculated value of the block with reference frame if larger than the predetermine thresholdn the block is selected as the occlusion area. In order to interpolate the occlusion area, we perform re-search to obtain the osiomal block considerhe osiomnumber of available ne block consblock. The experimental results show that performance of the proposed algorithm has better PSNR and visual quality than the conventional methods.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.11A
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• pp.1066-1072
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• 2010

In this paper we proposed a multi event handling surveillance system using multiple PTZ cameras. One event is assigned to each PTZ camera to detect unusual situation. If a new object appears in the scene while a camera is tracking the old one, it can not handle two objects simultaneously. In the second case that the object moves out of the scene during the tracking, the camera loses the object. In the proposed method, the nearby camera takes the role to trace the new one or detect the lost one in each case. The nearby camera can get the new object location information from old camera and set the seamless event link for the object. Our simulation result shows the continuous camera-to-camera object tracking performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.4B
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• pp.659-669
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• 2010

The P2P IPTV will create a new paradigm for the Internet services. However, it cannot guarantee the reliability of their server and QoS because of using common Internet users(peers) for SIP server or relay server, though the infrastructural cost is low. This paper proposes the ISP-based P2P IPTV architecture which can solute the limitations of conventional P2P-based IPTV. In this model, ISP can build P2P overlay network with ISP servers and directly manage each server needed for session connection. So, the servers have higher performance and better reliability than previous one. Besides, robustness is improved because each sever is set by P2P overlay network. To evaluate the characteristics of the ISP-based P2P IPTV architecture, we simulate it for some parameters which are end-to-end streaming delay time, connection delay time and traffic amount. We compared the proposed architecture with the conventional P2P architecture about video service and confirmed that the performance of ISP-based P2P IPTV is better than conventional P2P based IPTV.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.11B
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• pp.1151-1168
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• 2009

Improving packet loss does not necessarily coincide with the improvement in user perceivable QoS because each frame carries different degree of importance. We propose Significance-aware packet scheduling (SAPS) to maximize user perceivable QoS. SAPS carries out two fundamental issues of packet scheduling: "What to transmit" and "When to transmit?" To adapt to the available bandwidth, it is necessarily to transmit the subset of the data packets if the entire set of packets can not be transmitted. "Packet Significance" quantifies the importance of the frame by elaborately incorporating frames' dependency. Greedy approach is used in selecting packets and transmission schedule is determined based on the Packet Significance. The proposed scheme is tested using publicly available MPEG-4 video clips. Decoding engine is embedded in the simulation software and user perceivable QoS is exposeed in termstermiSNR. Throughout the simulation based experiment, the performance of the proposed scheme is compared two other schemes: Size-based packet scheduling and Bit-rate based best effort packet scheduling. SAPS successfully incorporates the semantics of a packet and improves user perceivable QoS significantly. It successfully provides unequal protection to more important packets.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.8C
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• pp.712-719
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• 2007

In this paper, we propose a new, effective, fast motion estimation algorithms using $4{\times}4$ pixels Hadamard transform. The Hadamard transform has the advantage of simplicity because it uses only addition and subtraction. Motion estimation is composed of three stages. First, it should be decided whether to terminate the search early and use a previous motion vector with DC(Direct Current) coefficients. Then the adaptive matching scan order for motion estimation should be determined according to the image complexity using AC(Alternating Current) coefficients. Experimentally, we adapted this algorithms to MVFAST and PMVFAST algorithms, and the proposed algorithms turn out to be very efficient in terms of computational speed while remaining almost the same in terms of PSNR(Peak Signal-to-Noise Ratio) compared to MVFAST and PMVFAST algorithms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.11B
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• pp.1005-1012
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• 2008

According to an aging population has dramatically increased in over the world, silver care becomes more important than other field. In this paper, we design and implement an old age patient care system that allows a carer to instantly monitor the status of proteges and notifies emergency of a patient to a medical institute. The system uses RFIDs and infrared sensors implemented in embedded software to analyze the activity and movement detection of the elderly. And the home gateway allows easy integration with heterogeneous devices by employing OSGi that is a middleware standard for home gateways. We can verify the information on the activity per day and the activity per week by Web browsers and view realtime video on the elderly by Web Cam using the implemented system. The system also can send us cell phone messages and E-mail in case of emergency.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.6A
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• pp.676-684
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• 2008

In digital video broadcasting-terrestrial (DVB-T), which is the European digital terrestrial television standard, the orthogonal frequency division multiplexing (OFDM) has been adopted for signal transmission. The main reasons using OFDM are to increase the robustness against the frequency selective fading and impulse noise, and to use available bandwidth efficiently. However, channel variation within an OFDM symbol destroys orthogonality between subcarriers, resulting in inter-carrier interference (ICI), which increases an error floor in proportional to maximum Doppler spread. This paper provides an ICI analysis in both time and frequency domains while existing literatures analyze the ICI effects mainly in frequency domain and proposes the algorithms that estimate the channel impulse response and channel variation using least square (LS) algorithm which is the most simple channel estimation technique. And we propose adaptive channel estimation algorithm that estimates the velocity of terminals. The simulation results show that proposed algorithm has similar performance with about 1.5% computational complexity of noise and ICI reduction LS algorithm in low speed environments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.5
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• pp.409-419
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• 2013

Kinect released by Microsoft in November 2010 is a motion sensing camera in xbox360 and gives depth and color images. However, Kinect camera also generates holes and noise around object boundaries in the obtained images because it uses infrared pattern. Also, boundary flickering phenomenon occurs. Therefore, we propose a real-time virtual-view video synthesis algorithm which results in a high-quality virtual view by solving these problems. In the proposed algorithm, holes around the boundary are filled by using the joint bilateral filter. Color image is converted into intensity image and then flickering pixels are searched by analyzing the variation of intensity and depth images. Finally, boundary flickering phenomenon can be reduced by converting values of flickering pixels into the maximum pixel value of a previous depth image and virtual views are generated by applying 3D warping technique. Holes existing on regions that are not part of occlusion region are also filled with a center pixel value of the highest reliability block after the final block reliability is calculated by using a block based gradient searching algorithm with block reliability. The experimental results show that the proposed algorithm generated the virtual view image in real-time.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.2C
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• pp.110-120
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• 2003

In this paper, we propose a Multiresolution Motion Estimation(MRME) adapted to Low-Band-Shift(LBS) method in wavelet domain. To overcome shift-variant property on wavelet coefficients, the LBS was previously proposed. This method which is applied to reference frame in video coding technique, has superior performance in terms of rate-distortion characteristic. However, this method needs more memory and computational complexity. In this paper, The computational complexity of the proposed method(LBS-MRME) is about 15.6% of that of existing method at 3-level wavelet transform. And although it has about 7 times as much as existing method's motion vector since each subband has different motion vector, it decreases motion compensated prediction error by detailed motion estimation, and then has better efficient coding performance. The experimental results with the proposed method showed about 0.3∼11.6% improvement of MAD performance in case of lossless coding, and 0.3∼3.0㏈ improvement of PSNR performance at the same bit rate in case of lossy coding.