• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.5
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• pp.798-807
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• 2021

The directivity characteristics of acoustic transducers for conventional single-beam echo sounders considerably limit the detection of fish-size information in acoustic field surveys. To overcome this limitation, using the split-aperture technique to estimate the direction of arrival of single-echo signals from individual fish distributed within the sound beam represents the most reliable method for fish-size classification. For this purpose, we design and develop a split-beam data acquisition and processing system to obtain fish-size information in conjunction with a 50-kHz single-beam echo sounder. This split-beam data acquisition and processing system consists of a notebook PC, a field-programmable gate array board, an external single-transmitter module with a matching network, and four-channel receiver modules operating at a frequency of 50-kHz. The functionality of the developed split-beam data processor is tested and evaluated. Acoustic measurements in an experimental water tank showed that the developed data acquisition and processing system can be used as a fish-sizing echo sounder to estimate the size distribution of individual fish, although an external single-transmitter module with a matching network is required.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.7
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• pp.62-69
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• 1992

The conventional BMA is performed with the fixed block size. For better performance at low bitrate, the block size is required to be large in relatively stationary area, while small in moving area. Thus, in this paper, a video coding technique using variable block size model is proposed. It decides the block size based on the degree of local motion defined by the local mean and variance of blocks. Computer simulation shows that the proposed method gives comparable performance to the conventional one with less bits required for motion vector coding.

• Journal of Korea Multimedia Society
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• v.22 no.12
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• pp.1404-1414
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• 2019

Educational books commonly use some copyrighted images with various kinds of deformation for helping students understanding. When using several copyrighted images made by merging or editing distortion in legal, we need to pay a charge to original copyright holders for each image. In this paper, we propose an efficient matching algorithm by separating each copyrighted image with the merged and edited type including rotation, illumination change, and change of size. We use the Oriented FAST and Rotated BRIEF (ORB) method as a basic feature matching scheme. To improve the matching accuracy, we design a new MIN-MAX similarity in matching stage. With the distorted dataset, the proposed method shows up-to 97% of precision in experiments. Also, we demonstrate that the proposed similarity measure also outperforms compared to other measure which is commonly used.

• Journal of Korean Institute of Industrial Engineers
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• v.25 no.2
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• pp.233-239
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• 1999

With the increase of Internet protocol (IP) packets the performance of routers became an important issue in internetworking. In this paper we examined the matching algorithm in gigabit router which has input queue with virtual output queueing. Port partitioning concept is employed to reduce the computational burden of the scheduler within a switch. The input and output ports are divided into two groups such that the matching algorithm is implemented within each input-output pair group in parallel. The matching is performed by exchanging input and output port groups at every time slot to handle all incoming traffics. Two algorithms, maximal weight matching by port partitioning (MPP) and modified maximal weight matching by port partitioning (MMPP) are presented. MMPP has the lowest delay for every packet arrival rate. The buffer size on a port is approximately 20-60 packets depending on the packet arrival rates. The throughput is illustrated to be linear to the packet arrival rate, which can be achieved under highly efficient matching algorithm.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.2
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• pp.455-461
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• 2011

In object tracking using the block mating algorithm, it is not proper to use a fixed matching block to track an object of which size may be various and can be changed at any time. This paper defines an adaptive matching block for the dynamic environment and proposes a block matching algorithm for it. The matching block is composed of a main-block of $10{\times}10$ pixels and 8 sub-blocks of $6{\times}6$ pixels in a wide area of $42{\times}42$ pixels, the main-block located its center is used as an object block, and the sub-blocks located its boundary are used as candidates for the object block. The proposed algorithm extracts the object blocks from the sub-blocks by using their motion vectors for 10 previous frames and performs the block matching with the main block and them. The experiments for perform estimation show that the proposed algorithm extracts just valid object blocks from the matching block and keeps an object having free movement in image center area.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.3
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• pp.79-87
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• 1996

A new method for recognizing and locating partially occluded or overlapped two-dimensional objects regardless of their size, translation, and rotation, is presented. Dominant points approximating occuluding contoures of objects are generated by finding local maxima of smoothed k-cosine function, and then used to guide the contour segment matching procedure. Primitives between the dominant points are produced by projecting the local contours onto the line between the dominant points. Robust classification of primitives. Which is crucial for reliable partial shape matching, is performed using adaptive resonance theory (ART2). The matched primitives having similar scale factors and rotation angles are detected in the hough space to identify the presence of the given model in the object scene. Finally the translation vector is estimated by minimizing the mean squred error of the matched contur segment pairs. This model-based matching algorithm may be used in diveerse factory automation applications since models can be added or changed simply by training ART2 adaptively without modifying the matching algorithm.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.2
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• pp.126-136
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• 1998

One of the central problems in sereo matching is the selectionof the optimal window sizes for comparing image regions. The window size must be large enough to include enough variation for reliable matching, but small enough to avoid the effect of projection distortion. This paper discusses these problems with some novel algorithm based on iterativediffusion process at different disparity hypotheses. Also this paper proposes four kinds of diffusion algorithms to preseve discontinuity in stereo matching. We present and discuss extensive empirical results of algorithms based on various sets of synthetic and real image.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.7
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• pp.1288-1293
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• 2007

In this paper, a compact triplexer has been implemented for Cellular/GPS/USPCS applications. In order to realize the proposed triplexer, we use a low-temperature co-fired ceramic (LTCC) substrate to enable a fully compact integrated module using a multi-layer high-density architecture, and conjugate-match the channels instead of the open matching technique. The three dimensional design capability of LTCC substrates can reduce the overall size of the triplexer, resulting in dimensions on the order of $3.2\;mm\;{\times}\;2.5\;mm\;{\times}\;1\;mm$. The measured result shows that the triplexer has, in Cellular/GPS/USPCS bands, the insertion loss of less than 0.5dB, less than 1.7dB, and less than 0.9dB in order. Also, the triplexer has an isolation of more than 15dB in the cellular and USPCS bands and an isolation of more than 20dB in the GPS band.

• Journal of Korea Multimedia Society
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• v.23 no.1
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• pp.8-14
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• 2020

For a reliable fingerprinting system, improving fingerprint matching accuracy is crucial. In this paper, we try to improve a binary image fingerprint matching performance by utilizing auxiliary information, power mask, which is obtained while constructing fingerprint DB. The power mask is an expected robustness of each fingerprint bit. A caveat of the power mask is the increased storage cost of the fingerprint DB. This paper mitigates the problem by reducing the size of the power mask utilizing spatial correlation of an image. Experiments on a publicly-available image dataset confirmed that the power mask is effective in improving fingerprint matching accuracy.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.11
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• pp.2768-2775
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• 1996

VariableBlock Matching algorithm is effective for the estimation of motion vector at complexor edge region by means of using variable block size with respect to the image block. But since VBM algorithm requires considerable number of operations, to solve this problem, we present an algorithm which uses difference images and quad tree structure, and estimates motion using various fast block matching algorithms.