• Journal of the Korea Society of Computer and Information
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• v.23 no.1
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• pp.41-48
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• 2018

Recently, surveillance systems are widely used, and one of the key technologies in this surveillance system is to recognize and track objects. In order to track a moving object robustly and efficiently in a complex environment, it is necessary to extract the feature points in the interesting object and to track the object using the feature points. In this paper, we propose a method to track interesting objects in real time by eliminating unnecessary information from objects, generating feature point descriptors using only key feature points, and reducing computational complexity for object recognition. Experimental results show that the proposed method is faster and more robust than conventional methods, and can accurately track objects in various environments.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.8A
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• pp.784-789
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• 2006

In this paper, we propose a bitwise information decomposition algorithm for an M-PSK signal based on the Max-Log-MAP algorithm. In order to obtain the algorithm, we use a coordinate transformation from M-PSK to M-PAM signal space. Using the proposed algorithm, we analyze the performance of a Turbo iterative decoding method. The proposed algorithm can be applicable not only for a communication with PSK and iterative decoding method but for adaptive modulation and coding system.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.249-256
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• 2004

KRISO/KORDI is currently developing a deep-sea unmanned underwater vehicle (UUV) system which is composed of a launcher, an ROV, and an AUV. Two USBL acoustic positioning systems will be used for UUV's navigation. One is for the deep sea positioning of all three vehicles and the other is for AUV's guidance to the docking device on the launcher. In order to increase the position accuracy MFSK(Multiple Frequency Shift Keying) broadband signal will be used. As the first step to the implementation of a USBL system, this paper studies USBL positioning algorithm using MFSK signals. Firstly, the characteristics of MFSK signal is described with various MFSK parameters: number of frequencies, frequency step, center frequency, and pulse length. Time and phase delays between two received signals are estimated by using cross-correlation and cross-spectrum methods. Finally an USBL positioning algorithm is derived by converting the delays to difference of distances and applying trigonometry. The simulation results show that the position accuracy is improved highly when both cross-correlation and cross-spectrum of MFSK signals are used simultaneously.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.11
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• pp.116-123
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• 1994

A novel opto-digital pattern recognition method which has shift, rotation, and scale invariant properties is proposed for recognizing two dimensional images having straight lines. The algorithm is composed of three stages. In the first stage the line features of the image are extracted. The second stage imposes the shift, rotation, and scale invariant properties on the extracted features through normalizing procedure. The required normalizing equations are analytically explained. In the last stage, the artificial feedforward neural network is trained with the extracted features. In order to evaluated the proposed algorithm, nine different edge enhnaced binary images composed of straight lines are tested. Thus the proposed algorithm can recognize the patterns event though they are shifted, rotated, and scaled.

• The Transactions of the Korea Information Processing Society
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• v.7 no.8
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• pp.2421-2429
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• 2000

With the advance of wireless communications technology, mobile communications have become more convenient than ever. Nowadays, people can communicate with each other on any place at any time. However, because of the openness of wireless communications, the way to protect the privacy between communicating parties is becoming a very important issue. In this paper, we present a study on the authentication and message encryption algorithm to support roaming service to the GSM network. To propose an authentication and message encryption algorithm applicable to the GSM system, the security architecture of the GSM outlined in the GSM standard is briefly introduced. In the proposed cryptosystems we use a new hash function for user authentication and a stream cipher based on Linear Feedback Shift Register(LFSR) for message encryption and decryption. Moreover, each algorithm is programmed with C language and simulated on IBM-PC system and we analyze the randomness properties of the proposed algorithms by using statistical tests.

• The Journal of the Acoustical Society of Korea
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• v.40 no.4
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• pp.370-381
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• 2021

This paper presented an efficient transceiver structure of multiband Frequency Shift Keying (FSK) signals with direct sequence spread spectrum for maintaining covertness and performance. In aspect to covertness, direct sequence spread spectrum method, which multiplying by Pseudo Noise (PN) codes whose rate is much higher than that of data sequence, is employed. In aspect to performance, in order to overcome performance degradation caused by multipath and Doppler spreading, we applied multiband, turbo equalization, and weighting algorithm are applied. Based on the simulation results, by applying 4 number of multiband and number of chips are 8 and 32, experiments were conducted in a lake with a distance of moving from 300 m to 500 m between the transceivers. we confirmed that the performance was improved as the number of bands and chips are increased. Furthermore, the performance of multiband was improved when the proposed weighting algorithm was applied.

• Journal of IKEEE
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• v.27 no.4
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• pp.624-629
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• 2023

Estimation of signal parameters via rotational invariance techniques (ESPRIT) is an algorithm that estimates the angle of a signal arriving at an array antenna using the shift invariance property of an array antenna. ESPRIT offers the good trade-off between performance and complexity. However, the ESPRIT algorithm still requires high-complexity operations such as covariance matrix and eigenvalue decomposition, so implementation with a hardware processor is essential to estimate the angle of arrival in real time. In addition, ESPRIT processors should have high performance. The performance is related to the number of antennas, and the number of antennas required for each application are different. Therefore, we proposed an ESPRIT processor that provides 2 to 8 variable antenna configurations to meet the performance and complexity requirements according to the applied field. The proposed ESPRIT processor was designed using the Verilog-HDL and implemented on a field programmable gate array (FPGA).

• Journal of Electrical Engineering and Technology
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• v.3 no.1
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• pp.130-134
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• 2008

The increasing size of very large scale integration (VLSI) circuits, high transistor density, and popularity of low-power circuit and system design are making the minimization of power dissipation an important issue in VLSI design. Test Power dissipation is exceedingly high in scan based environments wherein scan chain transitions during the shift of test data further reflect into significant levels of circuit switching unnecessarily. Scan chain or cell modification lead to reduced dissipations of power. The ETC algorithm of previous work has weak points. Taking all of this into account, we therefore propose a new algorithm. Its name is RE_ETC. The proposed modifications in the scan chain consist of Exclusive-OR gate insertion and scan cell reordering, leading to significant power reductions with absolutely no area or performance penalty whatsoever. Experimental results confirm the considerable reductions in scan chain transitions. We show that modified scan cell has the improvement of test efficiency and power dissipations.

• The Journal of the Korea Contents Association
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• v.14 no.8
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• pp.30-39
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• 2014

The proposed watermark embedding algorithm uses histogram of difference image between a modified original image and predicted image. To increase the prediction performance of the predicted image, the reference pixels for prediction are adaptively selected and the other pixels are directionally interpolated with the reference pixels. The simulation result shows that the proposed algorithm gives good performances in the embedding capacity and the PSNR values.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.870-876
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• 1993

This paper presents a binary clustering network (BCN) and a heuristic algorithm to detect pitch for recognition of keywords in continuous speech. In order to classify nonlinear patterns, BCN separates patterns into binary clusters hierarchically and links same patterns at root level by using the supervised learning and the unsupervised learning. BCN has many desirable properties such as flexibility of dynamic structure, high classification accuracy, short learning time, and short recall time. Pitch Detection algorithm is a heuristic model that can solve the difficulties such as scaling invariance, time warping, time-shift invariance, and redundance. This recognition algorithm has shown recognition rates as high as 95% for speaker-dependent as well as multispeaker-dependent tests.