• Journal of the Institute of Convergence Signal Processing
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• v.8 no.3
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• pp.143-148
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• 2007

The many studies have been proceeding to express accurately the feature of a sudden signal and a uncertain system in the image processing field. It is well know that Fourier Transform is widely used for frequency analysis of any signal. However, The frequency transform domain is not used for expressing the sudden signal change and non-stationary signal at the time-axis by this method. This paper describes of image analysis by discrete wavelet transform. Wavelet modulus maxima on transformed plane gives the Lipschitz exponent expression, which is useful to examine the characteristics of signal or the edge of an image. It is possible to reconstruct the original image only using the few maxima points. The fractal analysis is applied as an examples. The visualized image of oil flow on a ship model is analyzed. The fractal variable is obtained by the maxima analysis and the good results on the exprement is obtained by the visualized image analysis.

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.2
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• pp.157-162
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• 2010

In this paper we propose a fractal analysis based on the discrete wavelet transform. It is well known that Fourier Transform is widely used for frequency analysis of random signal. However, the frequency domain is not used for expressing the sudden signal change and non-stationary signal at the time-axis by this method. Maximum value in the wavelet modules can be expressed by the Lipschitz exponent, which is useful to represent the characteristics of signal or the edge of an image. It is possible to reconstruct the original image only by using the few maximum points. The v possible image It iusing oil was acquired to interpret the maximum value. ufter that, it was applied to the v possible image of a ship model. In addition, the fractal dimens by by the conlapse process of the sediment particle was examined. In this paper, the fractal dimens by has been obtained by the maximum value and the experiment obtained from the visualized image also acquired the same result as existing methods.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.4
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• pp.406-414
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• 2001

Ultrasonic guided waves were explored to apply them to the long range inspection of polyethylene coated steel gas pipes. The steel pipes have such dimensions as 190.7mm inside diameter and 5.3mm thickness. The outside surface of the pipe is coated by a polyethylene layer of $1.9{\pm}0.5mm$ thickness. Non-axisymmetric guided waves were excited on the outside surface of the polyethylene coated pipe by using a 0.5MHz transducer with a variable angle shoe. Frequency and phase velocity tuning was used to find optimum guided wave modes for the inspection. The dispersive characteristics of the modes were analyzed in time-frequency representation obtained by short time Fourier transforms. Sample results were presented for artificial defects such as wall thinning and hole.

• Conservation Science in Museum
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• v.13
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• pp.37-44
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• 2012

White crystals on 46 costumes excavated from Shim Su-Ryun(1534 - 1589)'s tomb were examined their characterization and distribution. In 36 of such samples, white crystals with different shape and hardness were found. The formation of crystals did not correlated with a kind and use of textiles. However, crystals were found in the back side than the front of costume, specially around the marks of shrouding dead body. White crystals from 7 textiles were investigated by EPMA, XRD, or FT-IR. The composition of white crystal was analysed by EPMA and the structure characterization of crystals was used by X-ray diffraction. FT-IR spectroscopy was applied to check if non-crystalline compounds were also present. Mg and P were detected as the main element of white crystals and these compounds were identified a struvite and newberyite, the inorganic mineral magnesium ammonium phosphates. Struvite precipitation are influenced by many factors including concentration of Mg²⁺, NH₄⁺, and PO₄^3- ions, pH, and temperatures. It is assumed that magnesium, phosphorous, ammonia, a base material of struvite comes from decomposition product of human body. Tomb covered with lime, a unique triple-structure in Joseon period offering the basic condition, an anaerobe in a coffin, and high magnesium concentration of outer coffin with lime can be inferred as important factor for precipitation of crystals.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.3
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• pp.108-115
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• 1990

This paper describes the design and fabrication of a processing element that will be used as a component in the construction of a two dimensional systolic for FFT. The chip performs data shuffling and radix-2 decimation-in-time (DIT) butterfly arithmetic. It consists of a data routing unit, internal control logic and HBA unit which computes butterfly arithmetic. The 6.5K transistors processing element designed with standard cells has been fabricated with a 2u'm double metal CMOS process, and evaluated by wafer probing measurements. The measured characteristics show that a HBA can be computed in 0.5 usec with a 20MHz clok, and it is estimated that the FFT of length 1024 can be transformed in 11.2 usec.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.42 no.2 s.302
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• pp.143-150
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• 2005

This paper proposes a new $radix-2^4$ FFT algorithm and an efficient pipeline architecture based on this new algorithm for OFDM systems. The pipeline architecture based on the new algorithm has the same number of multipliers as that of the $radix-2^2$ algorithm. However, the multiplier complexity could be reduced by more than $30\%$ by replacing one half of the programmable complex multipliers by the newly proposed CSD constant complex multipliers. From synthesis simulations of a standard 0.35um CMOS Samsung process, a proposed CSD constant complex multiplier achieved more than $60\%$ area efficiency when compared with the conventional programmable complex multiplier. This promoted efficiency can be used for the design of a long length FFT processor in wireless OFDM applications which needs more power and area efficiency.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.9
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• pp.1115-1124
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• 1988

A two-dimensional systolic array for fast Fourier transform, which has a regular and recursive VLSI architecture is presented. The array is constructed with identical processing elements (PE) in mesh type, and due to its modularity, it can be expanded to an arbitrary size. A processing element consists of two data routing units, a butterfly arithmetic unit and a simple control unit. The array computes FFT through three procedures` I/O pipelining, data shuffling and butterfly arithmetic. By utilizing parallelism, pipelining and local communication geometry during data movement, the two-dimensional systolic array eliminates global and irregular commutation problems, which have been a limiting factor in VLSI implementation of FFT processor. The systolic array executes a half butterfly arithmetic based on a distributed arithmetic that can carry out multiplication with only adders. Also, the systolic array provides 100% PE activity, i.e., none of the PEs are idle at any time. A chip for half butterfly arithmetic, which consists of two BLC adders and registers, has been fabricated using a 3-um single metal P-well CMOS technology. With the half butterfly arithmetic execution time of about 500 ns which has been obtained b critical path delay simulation, totla FFT execution time for 1024 points is estimated about 16.6 us at clock frequency of 20MHz. A one-PE chip expnsible to anly size of array is being fabricated using a 2-um, double metal, P-well CMOS process. The chip was layouted using standard cell library and macrocell of BLC adder with the aid of auto-routing software. It consists of around 6000 transistors and 68 I/O pads on 3.4x2.8mm\ulcornerarea. A built-i self-testing circuit, BILBO (Built-In Logic Block Observation), was employed at the expense of 3% hardware overhead.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.3 no.2 s.5
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• pp.19-28
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• 2004

This paper shows how to compensate the skew from the traffic sign included in the natural image and extract the text. The research deals with the Process related to the array image. Ail the process comprises four steps. In the first fart we Perform the preprocessing and Canny edge extraction for the edge in the natural image. In the second pan we perform preprocessing and postprocessing for Hough Transform in order to extract the skewed angle. In the third part we remove the noise images and the complex lines, and then extract the candidate region using the features of the text. In the last part after performing the local binarization in the extracted candidate region, we demonstrate the text extraction by using the differences of the features which appeared between the tett and the non-text in order to select the unnecessary non-text. After carrying out an experiment with the natural image of 100 Pieces that includes the traffic sign. The research indicates a 82.54 percent extraction of the text and a 79.69 percent accuracy of the extraction, and this improved more accurate text extraction in comparison with the existing works such as the method using RLS(Run Length Smoothing) or Fourier Transform. Also this research shows a 94.5 percent extraction in respect of the extraction on the skewed angle. That improved a 26 percent, compared with the way used only Hough Transform. The research is applied to giving the information of the location regarding the walking aid system for the blind or the operation of a driverless vehicle