• Journal of Satellite, Information and Communications
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• v.9 no.4
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• pp.57-62
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• 2014

In this paper, we proposed and implemented a crime pattern analysis algorithm using big data. The proposed algorithm uses crime-related big data collected and published in the supreme prosecutors' office. The algorithm analyzed crime patterns in Seoul city from 2011 to 2013 using the spatial statistics analysis like the standard deviational ellipse and spatial density analysis. Using crime frequency, We calculated the crime probability and danger factors of crime areas, time, date, and places. Through a result we analyzed spatial statistics. As the result of the proposed algorithm, we could grasp differences in crime patterns of Seoul city, and we calculated degree of risk through analysis of crime pattern and danger factor.

• Journal of Satellite, Information and Communications
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• v.12 no.2
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• pp.1-10
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• 2017

In this paper we propose three existing reflection removal algorithms and one proposed algorithm to estimate accurate targets in near field using IR-UWB (Impulse-Radio Ultra Wideband) radar. The received signal includes unnecessary reflected wave signals to the target signal. A reflective cancellation algorithm was used to remove unnecessary signals and estimate only the correct target signal. The location of the targets is estimated in real time with one transmitting antenna and one receiving antenna. In order to overcome the disadvantages of the existing three reflection removal algorithms, we propose a new reflection removal algorithm and estimate the most accurate target. Also we used DSP(Digital Signal Processor) to install the external mounting of vehicles. This paper will contribute to the study of the future reflections.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.3
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• pp.289-294
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• 2002

A valid speech-sound block can be classified to provide important information for speech recognition. The classification of the speech-sound block comes from the MRA(multi-resolution analysis) property of the DWT(discrete wavelet transform), which is used to reduce the computational time for the pre-processing of speech recognition. The merging algorithm is proposed to extract valid speech-sounds in terms of position and frequency range. It needs some numerical methods for an adaptive DWT implementation and performs unvoiced/voiced classification and denoising. Since the merging algorithm can decide the processing parameters relating to voices only and is independent of system noises, it is useful for extracting valid speech-sounds. The merging algorithm has an adaptive feature for arbitrary system noises and an excellent denoising SNR(signal-to-nolle ratio).

• The Transactions of the Korea Information Processing Society
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• v.6 no.7
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• pp.1980-1987
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• 1999

Restored image is always lower quality than original one due to distortion and noise. The purpose of image restoration is to improve the image quality by fixing the noise or distortion information. One category of spatial filters for image restoration is linear filter. This filter algorithm is easily implemented and can be suppressed the Gaussian noise effectively, but not so good performance for spot or impulse noise. In this paper, we propose the nonlinear spatial filter algorithm for image restoration called the optimal adaptive multistage filter(OAMF). The OAMF is used to reduce the filtering time, increases the noise suppression ratio and preserves the edge information. The OAMF optimizes the adaptive multistage filter(AMF) by using weight learning algorithm of back-propagation learning algorithm. Simulation results of this filter algorithm are presented and discussed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2369-2378
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• 2009

In this paper, we implement measurement functionality for performance measurement of the GSM (Global System for Mobile Communication) terminal by using software. Generally speaking, the receiving algorithms in normal modems cannot be used directly to the measurement system due to the lack of the algorithm accuracy. In this paper, we propose the new receiver algorithm for precise GSM signal measurements. In the receiving algorithm, 2-stage (coarse stage, fine stage) parameters estimation (symbol-timing, frequency offset, carrier phase) scheme is used. To improve the estimation accuracy, we increase the number of the received signal samples by interpolation. The proposed GSM signal measurement algorithm can be used for verifying the hardware measurement system. In addition, the proposed algorithm can be used for the commercial system through code execution speed optimization.

• The KIPS Transactions:PartC
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• v.17C no.2
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• pp.145-152
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• 2010

In this paper, we first propose a fast division algorithm in GF($2^{163}$) using standard basis representation, and then it is mapped into divider for GF($2^{163}$) with iterative hardware structure. The proposed algorithm is based on the binary ExtendedGCD algorithm, and the arithmetic operations for modular reduction are performed within only one "while-statement" unlike conventional approach which uses two "while-statement". In this paper, we use reduction polynomial $f(x)=x^{163}+x^7+x^6+x^3+1$ that is recommended in SEC2(Standards for Efficient Cryptography) using standard basis representation, where degree m = 163. We also have implemented the proposed iterative architecture in FPGA using Verilog HDL, and it operates at a clock frequency of 85 MHz on Xilinx-VirtexII XC2V8000 FPGA device. From implementation results, we will show that computation speed of the proposed scheme is significantly improved than the existing two approaches.

• Journal of IKEEE
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• v.23 no.3
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• pp.971-977
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• 2019

This paper presents an experimental result showing the encryption and decryption times of the AES and LEA algorithms. AES and LEA algorithms are international and Korean standards for block ciphers, respectively. Through experiments, this paper investigates the applicability of the LEA algorithm for light weight IoT devices. In order to measure the encryption and decryption times, 256-bit and 128-bit secret keys were randomly generated for AES and LEA, respectively. Under our test environment using an Arduino microcontroller, the AES algorithm takes about 45ms for encryption and decryption processes, whereas the LEA algorithm takes about 4ms. Even though processing times of each algorithm may vary much under different implementation and test environments, this experimental result shows that the LEA algorithm can be applied to many light weight IoT devices for security goals.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.3
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• pp.323-330
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• 2021

Recently, the advantages of high-speed arithmetic in quantum computers have been known, and interest in quantum circuits utilizing qubits has increased. The Grover algorithm is a quantum algorithm that can reduce n-bit security level symmetric key cryptography and hash functions to n/2-bit security level. Since the Grover algorithm work on quantum computers, the symmetric cryptographic technique and hash function to be applied must be implemented in a quantum circuit. This is the motivation for these studies, and recently, research on implementing symmetric cryptographic technique and hash functions in quantum circuits has been actively conducted. However, at present, in a situation where the number of qubits is limited, we are interested in implementing with the minimum number of qubits and aim for efficient implementation. In this paper, the domestic hash function LSH is efficiently implemented using qubits recycling and pre-computation. Also, major operations such as Mix and Final were efficiently implemented as quantum circuits using ProjectQ, a quantum programming tool provided by IBM, and the quantum resources required for this were evaluated.

• Journal of Integrative Natural Science
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• v.15 no.3
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• pp.99-110
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• 2022

Solar photovoltaic (PV) system shows a non-linear current (I) -voltage (V) characteristics, which depends on the surrounding environment factors, such as irradiance, temperature, and the wind. Solar PV system, with current (I) - voltage (V) and power (P) - Voltage (V) characteristics, specifies a unique operating point at where the possible maximum power point (MPP) is delivered. At the MPP, the PV array operates at maximum power efficiency. In order to continuously harvest maximum power at any point of time from solar PV modules, a good MPPT algorithms need to be employed. Currently, due to its simplicity and easy implementation, Perturb and Observe (P&O) algorithms are the most commonly used MPPT control method in the PV systems but it has a drawback at suddenly varying environment situations, due to constant step size. In this paper, to overcome the difficulties of the fast changing environment and suddenly changing the power of PV array due to constant step size in the P&O algorithm, least mean Square (LMS) methods is proposed together with P&O MPPT algorithm which is superior to traditional P&O MPPT. PV output power is predicted using LMS method to improve the tracking speed and deduce the possibility of misjudgment of increasing and decreasing the PV output. Simulation results shows that the proposed MPPT technique can track the MPP accurately as well as its dynamic response is very fast in response to the change of environmental parameters in comparison with the conventional P&O MPPT algorithm, and improves system performance.

• The Journal of the Convergence on Culture Technology
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• v.9 no.5
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• pp.517-522
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• 2023

Existing radars have been developed by applying RF sub-array algorithms, and recently, fully digital Multiple-Input Multiple-Output (MIMO) radar algorithms have been implemented for vehicle radars. In this paper, the radar algorithm applying the Phased MIMO method to the hardware of the RF sub-array method, which is an unsecured technology, was implemented and verified in real time. In order to secure RF sub-array Phased MIMO algorithm technology, a hardware structure for FPGA-based real-time signal processing was presented, and performance was first predicted through design and simulation. Through this, the digital signal of FPGA-based broadband MIMO FMCW radar The processing hardware was developed, and the Phased MIMO radar algorithm of the RF sub-Array method was finally implemented and verified in real time. Based on this, it is judged that it will be possible to secure and apply core technologies necessary for terahertz band radar in the future.