• Korean Journal of Remote Sensing
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• v.26 no.5
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• pp.581-591
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• 2010

In this paper, we proposed a new wavelet-based image fusion algorithm, which has advantages in both frequency and spatial domains for signal analysis. The developed algorithm compares the ratio of SAR image signal to optical image signal and assigns the SAR image signal to the fused image if the ratio is larger than a predefined threshold value. If the ratio is smaller than the threshold value, the fused image signal is determined by a weighted sum of optical and SAR image signal. The fusion rules consider the ratio of SAR image signal to optical image signal, image gradient and local variance of each image signal. We evaluated the proposed algorithm using Ikonos and TerraSAR-X satellite images. The proposed method showed better performance than the conventional methods which take only relatively strong SAR image signals in the fused image, in terms of entropy, image clarity, spatial frequency and speckle index.

• Journal of Korea Water Resources Association
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• v.54 no.11
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• pp.891-901
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• 2021

In this study, a hydrological cycle soundness evaluation method was developed using monthly meteorological observation data. The Gyeongan stream watershed was divided into five sub-basins and eight criteria were established for hydrological cycle evaluation: the number of non-rainfall day, the number of non-rainfall day fluctuation, over 30 mm per day, over 30 mm per day fluctuation, average river level, average river level fluctuation, average groundwater level and average groundwater level fluctuation. Observation data were normalized and weights for evaluation by each sub-basin were calculated using the entropy method. The hydrological cycle soundness evaluation indices were calculated using TOPSIS applying the calculated weight value. As a result of the study, it was found that the hydrological cycle soundness was unstable in the Gyeongan-upstream from November to January, the Gyeongan-suwipyo from February to April, Gonjiam stream from April to May, and the Gyeongan-downstream from November to February. In this study, the developed technique is expected to serve as a quantitative basis for policy decision to recover hydrological cycle soundness.

• Journal of Advanced Navigation Technology
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• v.14 no.1
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• pp.102-107
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• 2010

This paper presented a rate-distortion estimation method for effective mode decision in H.264/AVC. In this approach, in order to decide a mode, laplacian distribution modeling of DCT coefficients is utilized, which do not need to such process as quantization, entropy coding. From the simulation results, proposed a method showed that rate-distortion between proposed scheme and practical value was almost the same and performed 0.02dB of PSNR gain.

• Journal of Microbiology and Biotechnology
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• v.15 no.3
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• pp.672-677
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• 2005

The standard reference collection of strains for E. coli, the ECOR collection, was analyzed by a genome-based typing method. Seventy-one ECOR strains were subjected to repetitive extragenic palindromic PCR genome fingerprinting with BOX primers (BOX-PCR). Using a similarity value of 0.8 or more after cluster analysis of BOX-PCR fingerprinting patterns to define the same genotypes, we identified 28 genotypes in the ECOR collection. Shannon's entropy-based diversity index was 3.07, and the incident-based coverage estimator indicated potentially 420 genotypes among E. coli populations. Chi-square test of goodness-of-fit showed statistically significant association between the genotypes defined by BOX-PCR fingerprinting and the groups previously defined by multi-locus enzyme electrophoresis. This study suggests that the diversification of E. coli strains in natural populations is actively ongoing, and rep-PCR fingerprinting is a convenient and reliable method to type E. coli strains for the purposes ranging from ecology to quarantine.ine.

• Journal of Information Processing Systems
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• v.19 no.4
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• pp.417-426
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• 2023

To improve the effect of image restoration and solve the image detail loss, an image dehazing enhancement algorithm based on mean guided filtering is proposed. The superpixel calculation method is used to pre-segment the original foggy image to obtain different sub-regions. The Ncut algorithm is used to segment the original image, and it outputs the segmented image until there is no more region merging in the image. By means of the mean-guided filtering method, the minimum value is selected as the value of the current pixel point in the local small block of the dark image, and the dark primary color image is obtained, and its transmittance is calculated to obtain the image edge detection result. According to the prior law of dark channel, a classic image dehazing enhancement model is established, and the model is combined with a median filter with low computational complexity to denoise the image in real time and maintain the jump of the mutation area to achieve image dehazing enhancement. The experimental results show that the image dehazing and enhancement effect of the proposed algorithm has obvious advantages, can retain a large amount of image detail information, and the values of information entropy, peak signal-to-noise ratio, and structural similarity are high. The research innovatively combines a variety of methods to achieve image dehazing and improve the quality effect. Through segmentation, filtering, denoising and other operations, the image quality is effectively improved, which provides an important reference for the improvement of image processing technology.

• Journal of Korean Institute of Industrial Engineers
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• v.26 no.4
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• pp.363-375
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• 2000

In this paper we propose a content-based image retrieval method that can search large image databases efficiently by color, texture, and shape content. Quantized RGB histograms and the dominant triple (hue, saturation, and value), which are extracted from quantized HSV joint histogram in the local image region, are used for representing global/local color information in the image. Entropy and maximum entry from co-occurrence matrices are used for texture information and edge angle histogram is used for representing shape information. Relevance feedback approach, which has coupled proposed features, is used for obtaining better retrieval accuracy. Simulation results illustrate the above method provides 77.5 percent precision rate without relevance feedback and increased precision rate using relevance feedback for overall queries. We also present a new indexing method that supports fast retrieval in large image databases. Tree structures constructed by k-means algorithm, along with the idea of triangle inequality, eliminate candidate images for similarity calculation between query image and each database image. We find that the proposed method reduces calculation up to average 92.9 percent of the images from direct comparison.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1271-1275
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• 1987

With the stochastic process which consists of the harmonic sinusoid and the white nosie, the power spectrum of background EEG is estimated by the Pisarenko Harmonic Decomposition. The estimating results are examined and compared with the results from the maximum entropy spectral estimation, and the optimal order of this model can be determined from the eigen value's fluctuation of autocorrelation of background EEG. From the comparing results, this paper ensures that this method is possible to analyze the power spectrum of background EEG.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.270-273
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• 2007

In this paper, a SAR-despeck1ing approach of adaptive iteration based a Bayesian model using the lognormal distribution for image intensity and a Gibbs random field (GRF) for image texture is proposed for noise removal of the images that are corrupted by multiplicative speckle noise. When the image intensity is logarithmically transformed, the speckle noise is approximately Gaussian additive noise, and it tends to a normal probability much faster than the intensity distribution. The MRF is incorporated into digital image analysis by viewing pixel types as states of molecules in a lattice-like physical system. The iterative approach based on MRF is very effective for the inner areas of regions in the observed scene, but may result in yielding false reconstruction around the boundaries due to using wrong information of adjacent regions with different characteristics. The proposed method suggests an adaptive approach using variable parameters depending on the location of reconstructed area, that is, how near to the boundary. The proximity of boundary is estimated by the statistics based on edge value, standard deviation, entropy, and the 4th moment of intensity distribution.

• International Journal of Air-Conditioning and Refrigeration
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• v.17 no.2
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• pp.74-79
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• 2009

The performance of cryogenic refrigerator greatly depends on the effectiveness of heat exchanger, which generates major entropy at low temperature. There are numerous types of heat exchanger available, but it is not easy to apply most of them to cryogenic application because the cryogenic heat exchanger must have high effectiveness value as well as small conduction loss in the environment of considerable temperature difference. In this paper, two kinds of heat exchanger are noticeably introduced for high-effectiveness miniature cryogenic recuperator(recuperative heat ex-changer). Also, the flow mal-distribution problem, which is a critical issue of performance deterioration in a high-effectiveness recuperator, is addressed with simplified model, and its alleviation method is discussed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.9
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• pp.2341-2348
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• 1996

This paper proposes an image compression algorithm that adopts projection scheme on mean-residual metod. Sub-blocks of an image are encoded using mean-residual method where mean value is predicted according to that of neighboring blocks. Projection scheme with 8 directions is applied to the compression of residual signals of blocks. Projection vectors are finite-state vector quantized according to the projection angle of nighboring blocks in order to exploit the correlation among them. Side information to represent the repetition of projection is run-length coded while the information for projection direction is compressed using entropy encoding. The proposed scheme apears to be better in PSNR performance when compared with conventional projection scheme as well as in subjective quality preserving the edges of images better than most tranform methods which usually require heavy computation load.