• Journal of The Korean Astronomical Society
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• v.37 no.4
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• pp.211-216
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• 2004

We present the results of an H I aperture synthesis mosaic of the Large Magellanic Cloud (LMC), made by combining data from 1344 separate pointing centers using the Australia Telescope Compact' Array (ATCA) and the Parkes multibeam receiver. The resolution of the mosaiced images is 50" (<15 pc, using a distance to the LMC of 55kpc). This mosaic, with a spatial resolution .15 times higher than that which had been previously obtained, emphasises the turbulent and fractal structure of the ISM on the small scale, resulting from the dynamical feedback of the star formation processes with the ISM. We also have done a widefield panoramic survey of H$\alpha$ emission from the Magellanic Clouds with an imager mounted on the 16-inch telescope at Siding Spring Observatory. This survey produced H$\alpha$ images which are equal to the ATCA survey in area coverage and resolution. This survey allows us to produce a continuum-subtracted image of the entire LMC. In contrast with its appearance in the H$\alpha$ image, the LMC is remarkably symmetric in H I on the largest scales, with the bulk of the H I residing in a disk of diameter 8. $^{\circ}4$ (7.3 kpc) and a spiral structure is clearly seen. The structure of the neutral atomic ISM in the LMC is dominated by H I filaments combined with numerous shells and holes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.12A
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• pp.2059-2066
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• 2001

In this paper, we proposed a method to reduce the number of input pins in one-dimensional VLSI array for fractal image compression. We use quad-tree partition scheme and can reduce the number of the input pins up to 50% by sharing the domain\`s and the range\`s data input pins in the proposed VLSI array architecture. Also, we can reduce the input pins and simplify the internal operation circuit of the processing elements by eliminating a few number of bits of the least significant bits of the input data. We simulated using the 256$\times$256 and 512$\times$512 Lena images to verify performance of the proposed method. As the result of simulation, we can decompress the original image with about 32dB(PSNR) in spite of elimination of the least significant 2-bit in the original input data, and additionally reduce the number of input pins up to 25% compared to VLSI array sharing input pins of range and domain.

• Journal of Korea Multimedia Society
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• v.4 no.6
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• pp.518-523
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• 2001

This paper proposes the new method which is adopted in extracting character features and recognizing characters using fractal dimension of the Chaos theory which highly recolonizes a minute difference with strange attractor created from Henon system. This paper implements a high precision character recognition system. firstly, it gets features of mesh, projection and cross distance feature from character images. And their feature is converted into data of time series. Then using modified Henon system suggested in this paper, each characters attractor about standard Korean Character, KSC 5601 is reconstructed. Secondly, in order to analyze the Chaotic degree of each characters attractor, it gets last features of character image after calculating box-counting Dimension, Natural Measure, Information Bit, Information Dimension which are meant fractal dimension. An experimental result shows 97.49% character classification rates for 2350 Korean characters using proposed method in this paper.

• Journal of Korea Multimedia Society
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• v.8 no.6
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• pp.776-782
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• 2005

This paper presents a SPIHT image compression method using biorthogonal multi wavelets on [-1,1]. A family of biorthogonal scaling vectors is constructed using fractal interpolation function, and the associated biorthogonal multi wavelets are constructed. This paper uses biorthogonal multi wavelets to be supported in [-1,1] associated with biorthogonal scaling vectors to be supported in [-1,1]. The scaling vectors and wavelets remain biorthogonal when restricted to integer intervals, making them well suited for bounded domains. The experiment results of simulation of the proposed image compression using biorthogonal multiwavelets on [-1,1] based on SPIHT were found to be excellent PSNR for LENA and PEPPERS images except for BABOON image than already existing single wavelets and DGHM multi wavelets.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.3
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• pp.564-575
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• 1996

Conventional decoding procedures have some problems in order to obtain reconstructed images with high speed. In this paper, the solutions of these are studied and a new fast decoding algorithm is proposed. The proposed algorithm uses a convergence criterion that is used to reduce the redundant iteration in the conventional method and to determine continuation of decoding. The initical image similar to roiginal image is estimated firstly in this algorithm. From the simulation resuls, the proposed algorithm is able to achieve the reconstructed image within 3-4 iteration under the objective criterion. Without any increment of the memory, the quality of the image reconstructed by the proposed algorithm has same quality asthe conventional method.

• Journal of applied mathematics & informatics
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• v.42 no.3
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• pp.583-605
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• 2024

This paper discusses the properties of attractors of Type 1 IFS which construct self similar fractals on product spaces. General results like continuity theorem and Collage theorem for Type 1 IFS are established. An algebraic equivalent condition for the open set condition is studied to characterize the points outside a feasible open set. Connectedness properties of Type 1 IFS are mainly discussed. Equivalence condition for connectedness, arc wise connectedness and locally connectedness of a Type 1 IFS is established. A relation connecting separation properties and topological properties of Type 1 IFS attractors is studied using a generalized address system in product spaces. A construction of 3D fractal images is proposed as an application of the Type 1 IFS theory.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.46 no.6
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• pp.58-64
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• 2009

Digital radiography (DR) images are corrupted by the additive noise, and also distorted by system impulse response. These unwanted phenomena are obstacles to obtain the desired image. To recover the original image, we applied multiscale Wiener filters in wavelet domain for DR images. The multiscale Wiener filter is first proposed by Chen for the restoration of fractal signals which are distorted by the system impulse response and additive noise. In this paper, we extended the multiscale Wiener filter to the two dimensional data. To compare the performance of ours with others, some simulations are given for a couple of wavelet filters with different wavelet levels, system impulse reponses and various noise power. When the addive noise powers are between 20-32 dB, the signal to noise ratio(SNR) of the proposed system is 0.5-2.0 dB better than that of the traditional Wiener filter method.

• Journal of the Korean association of regional geographers
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• v.9 no.4
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• pp.481-492
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• 2003

This study aims to analyze quantitatively changes of forest and cropland landscape due to cropland increase toward higher mountain slope during 9 years from 1993 to 2002, using Landsat images and field survey in the vicinity of Manpo and Gangae cities, Jagang Province, Northwest Korea, During 9 years, cropland has increased as 49.9%, forest area decreased as 16%. The spatial characteristics of cropland changes present that average elevation of cropland are increased from 381m of 1993 year to 412m of 2002 year, and average gradient increased from $10^{\circ}$ to $13^{\circ}$. In increased area of cropland during 9 years, the average elevation is 455m, and average gradient is $15^{\circ}$ with maximum gradient $70^{\circ}$. Analysis of the patch phenomena by fragmentation of vegetation landscape show that number of patch increased from 394 to 1,241 and also values of shape index, and fractal dimension of vegetation are increased slightly, during 9 years. Croplands have developed mainly in mountain slopes of elevation between 450 to 750m. For improvement of agricultural productivity, it should be required political and social stabilization, international and South Korea's assistance, and restoration of mountain forest.

• Journal of the Korean GEO-environmental Society
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• v.17 no.3
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• pp.21-26
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• 2016

Soil particle shape analysis was conducted with sands from Jumujun, Korea and Ras Al Khair, Saudi Arabia. Two hundred times enlarged digital images of the particles of those two sands were obtained with an optical microscope. The resolution of the digital images was $640{\times}320$. By conducting digital image processing, the coordinates of the soil particle boundary were extracted. After mapping those coordinates to the complex space, Fourier transformation was performed and the coefficients of each trigonometry term were computed. The coefficients reflect the shape characteristics of the sand grains and are invariant to translation. To evaluate the shape itself excluding the size of the soil particle, the coefficient was normalized by the equivalent radius of soil particle; this is called Fourier descriptor. After analyzing the Fourier descriptors, it was found that the major characteristics of Jumunjin and Ras Al Khair sands were elongation and asymmetry. Furthermore, it was found that the particle shapes reflect the self-similar, fractal nature of the textural features. The effects of resolution on soil particle shape analysis was also studied. Regarding this, it was found that the significant Fourier descriptors were not significantly affected by the image resolution investigated in this study, but the descriptors associated with textural features were affected.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.4
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• pp.823-830
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• 2010

This study was designed to examine the morphological measurement and characteristics of trabecullae based on femoral radiographic image for prediction of osteoporosis. Study subjects were 34 females (average age of 62.1 years) and 6 males (average age of 60.1 years), they were categorized into normal group and osteoporosis group in accordance with the T-score value. Measurement of the bone density of femoral bone was measured with DEXA(Dual Energy X-ray absorptiometry). ROI(Region of interests) was selected on femoral neck and trochanter. Characteristics of trabecullae was analyzed by using the skeletonization analysis of trabecular image. Morphological measurement was analyzed through femoral radiographic image in order to examine the correlation with osteoporosis. The result demonstrated statistically significant correlation between neck cortical thickness, shaft width, shaft cortical thickness, periphery, mean gray level and trabeculae area with BMD average (T-score) of femoral part. The results show that morphological measurement and characteristics of trabecullae based on femoral radiographic images for osteoporosis prediction could be effective.