• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.12C
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• pp.1138-1146
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• 2009

Digital cameras adopting a single CCD detector collect image color by subsampling in three color planes and successively interpolating the information to reconstruct full-resolution color images. Therefore, to recovery of a full-resolution color image from a color filter array (CFA) like the Bayer pattern is generally considered as an interpolation issue for the unknown color components. In this paper, we first calculate luminance component value by combining R, G, B channel component information which is quite different from the conventional demosaicing algorithm. Because conventional system calculates G channel component followed by computing R and B channel components. Integrating the obtained gradient edge information and the improved weighting function in luminance component, a new edge sensitive demosaicing technique is presented. Based on 24 well known testing images, simulation results proved that our presented high-quality demosaicing technique shows the best image quality performance when compared with several recently presented techniques.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.7
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• pp.77-85
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• 2015

In this paper, we present a new method that can detect forged color region using color pattern decomposition and hypothesis testing approach. On the basis of the fact that the variance of the interpolated pixel is smaller than that of the original pixel, we use a statistical test method to judge the statistical inconsistency of variance. For this, we calculate the variance adopting a color pattern decomposition according to the demosaicking pattern. In addition, we apply high-pass filtering to enlarge the difference between the variances of original and interpolated pixel. Through experimental simulations, we can see that our proposed method can effectively detect forged color regions and shows superior detection performance compared to the conventional method.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.11
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• pp.857-861
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• 2012

FPN (fixed-pattern-noise) mainly comes from the device or pattern mismatches in pixel and color filter, pixel photodiode leakage in CMOS image sensor. In this paper, optical stack module related pixel FPN was investigated and the classification of pixel FPN contribution with the individual optical module process was presented. The methodology and procedure would be helpful in reducing the greater pixel FPN and distinguishing the complex FPN sources with respect to various noise factors.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.11a
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• pp.205-207
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• 2009

디지털 카메라를 이용한 영상 취득은 일반적으로 한 픽셀에서 세 가지 색상(적색, 녹색, 청색)의 값을 얻는 것을 목표로 한다. 하지만, 비용의 문제로 한 픽셀에서 한 가지의 색상만을 얻어 나머지 두 색상을 복원하는 방식을 널리 사용한다. 이를 demosaicking이라 하는데, 이 과정에는 1)각 색상 영상 내의 상관관계와 2)세 가지 색상 사이의 상관관계가 동시에 이용된다. 본 논문에서는 이 두 가지 상관관계를 이용하여 각 채널의 고주파 성분과 밝기 성분의 고주파 성분을 반복적으로 향상시키는 방법을 제안하였다. 첫 번째 단계에서는 밝기 성분을 이용하여 각 채널의 고주파 성분을 강화하고, 두 번째 단계에서 관측값을 이용하여 밝기 성분의 고주파 성분을 복원한다. 제안된 방법이 기존 방법과 주관적인 방법과 객관적인 방법으로 비교하여 우수함을 보인다.

• Analytical Science and Technology
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• v.8 no.4
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• pp.715-722
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• 1995

The structural characterization for series of polyesters has been done by time-of-flight secondary ion mass spectrometry (TOF-SIMS). Polymer fragments and intact oligomers composed of large numbers of repeat units have been investigated. Transesterification of polyesters in trifluoroacetic acid (TFA) and chlorodifluoroacetic acid (CFA) was monitored and reaction products were identified using TOF-SIMS. The shapes and intensities of clusters in transesterification spectra show good agreement with the theoretical isotope pattern. TOF-SIMS spectra were used to obtain information about the progress of the transesterification reaction.

• Journal of Broadcast Engineering
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• v.18 no.4
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• pp.619-630
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• 2013

In this paper, we propose an edge directed color demosaicing algorithm considering color channel correlation. The proposed method consists of local region classification step and edge directional interpolation step. In the first step, each region of a given Bayer image is classified as normal edge, pattern edge, and flat regions by using intra channel and inter channel gradients. Especially, two criteria and verification process for the normal edge and pattern edge classification are used to reduce edge direction estimation error, respectively. In the second step, edge directional interpolation process is performed according to characteristics of the classified regions. For horizontal and vertical directional interpolations, missing color components are obtained from interpolation equations based on intra channel and inter channel correlations in order to improve the performance of the directional interpolations. The simulation results show that the proposed algorithm outperforms conventional approaches in both objective and subjective terms.

• Journal of Distribution Science
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• v.12 no.9
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• pp.5-13
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• 2014

Purpose -This study is to measure the effects of retail legislations on small retailers and traditional markets. Research Design, Data, and Methodology - The authors have developed a questionnaire with five hypotheses on the basis of previous research results and six constructs: the improvement of sales volume, the number of customers, the improvement of store traffic, the increase of store staff, business expansion and retail regulation. Furthermore, the research has adopted a five-point Likert-scale technique. In order to increase research reliability as well as validity, the authors have adopted a few different research techniques such as exploratory factor analysis (EFA) and confirmatory factor analysis (CFA). Results - Although existing retail regulations might be better than nothing for now, the degree of retail constraints on large retailers should be strengthened. Furthermore, different legal methods to protect mom and pops are needed. Conclusions - In order to improve the effects of retail restrictions on large retailers, the research indicates that the central government should change a retail policy, that is, introduce new technical ways to keep mom and pops and conventional markets.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.215-218
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• 2009

In this paper, we analyze the performance of interpolation in demosaicing techniques for single sensor digital camera. We choose BI(bilinear interpolation), ACPI(adaptive color plane interpolation), ECI(effective color interpolation), Ideal ACPI, and EECI(Enhanced effective color interpolation) in the literature of demosacing techniques since they provide low-complexity and substantial image quality. We survey the algorithms and simulate them. To evaluate the methods in terms of objective image quality and complexity, 24 Kodak images will be used in this experiment. Experimental results show that the ECI method is better than others in terms of image quality versus complexity.

• Journal of Sasang Constitutional Medicine
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• v.33 no.3
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• pp.54-71
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• 2021

Objectives The purpose of this study was to revise Sasang Digestive Function Inventory (SDFI) and improve its validity and reliability using clinical data. Methods The Sasang type and Cold-Heat pattern differentiation by certified clinical specialist and responses to SDFI items were acquired from 419 hospital patients. The revision of SDFI was performed using item analysis and Explorative Factor Analysis (EFA). Furthermore, the validity and reliability of the revised SDFI (rSDFI) were investigated using Confirmatory Factor Analysis (CFA), Internal Consistency and Item Response Theory (IRT). And, clinical significance of the rSDFI was examined for the differentiation of Sasang types and Cold-Heat patterns. Results The number of the SDFI items were modified from 21 to 15. And, the validity and reliability of the rSDFI subscale structure were found to be acceptable. The scores of rSDFI-total and rSDFI-E significantly decreased in the order of Tae-Eum (TE), So-Yang (SY), So-Eum (SE) types, and the rSDFI score of SE type was significantly lower than that of TE and SY types. The rSDFI-total score could differentiate Cold-Heat pattern in both SY and SE types. And the difference of digestive function between Cold and Heat pattern of SE type could be explained with the rSDFI-D score. The rSDFI-total score in Cold pattern significantly decreased in the order of TE, SY, and SE types, and the rSDFI-total score of TE type is significantly higher than that of SE type in Heat pattern. Conclusions Current results demonstrated the reliability, validity and clinical usefulness of the rSDFI in clinical patients. Therefore, rSDFI can be utilized as an objective clinical measure supporting the differential diagnosis of Sasang typology.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.11 s.353
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• pp.26-36
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• 2006

In this paper, we propose a cost-effective color filter may (CFA) demosaicing method for digital still cameras in which a single CCD or CMOS image sensor is used. Since a CFA is adopted, we must interpolate missing color values in the red, green and blue channels at each pixel location. While most state-of-the-art algorithms invest a great deal of computational effort in the enhancement of the reconstructed image to overcome the color artifacts, we focus on eliminating the color artifacts with low computational complexity. Using spatial correlation of the adjacent pixels, the edge-directional information of the neighbor pixels is used for determining the edge direction of the current pixel. We apply our method to the state-of-the-art algorithms which use edge-directed methods to interpolate the missing color channels. The experiment results show that the proposed method enhances the demosaiced image qualify from $0.09{\sim}0.47dB$ in PSNR depending on the basis algorithm by removing most of the color artifacts. The proposed method was implemented and verified successfully using verilog HDL and FPGA. It was synthesized to gate-level circuits using 0.25um CMOS standard cell library. The total logic gate count is 12K, and five line memories are used.