• Journal of Korea Society of Digital Industry and Information Management
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• v.15 no.1
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• pp.99-107
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• 2019

Retinex-based image enhancement is a technique that utilizes the property that the human visual characteristics are sensitive to the difference from the surrounding pixel value rather than the pixel value itself. These Retinex-based algorithms show different characteristics of the improved image depending on the applied color space or gamma correction. In this paper, we set eight different experimental conditions according to the application of color space and gamma correction, and analyze the objective and subjective performance of each Retinex based image enhancement algorithm and apply it to the implementation of Retinex based algorithm. In the case of gamma correction, quantitative low entropy images and low contrast images are obtained. The application of Retinex technique in HSI color space rather than RGB color space is found to be high in overall subjective image quality as well as maintaining color.

• Current Optics and Photonics
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• v.6 no.3
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• pp.304-312
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• 2022

Digital images of cultural relics captured using line scan cameras present limitations due to uneven intensity and low contrast. To address this issue, this report proposes a colour linear array image enhancement method that can maintain a constant colour. First, the colour linear array image is converted from the red-green-blue (RGB) colour space into the hue-saturation-intensity colour space, and the three components of hue, saturation, and intensity are separated. Subsequently, the hue and saturation components are held constant while the intensity component is processed using the established intensity compensation model to eliminate the uneven intensity of the image. On this basis, the contrast of the intensity component is enhanced using an improved local contrast enhancement method. Finally, the processed image is converted into the RGB colour space. The experimental results indicate that the proposed method can significantly improve the visual effect of colour linear array images. Moreover, the objective quality evaluation parameters are improved compared to those determined using existing methods.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.6C
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• pp.634-647
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• 2003

In MPEG-4 FGS (fine granular scalability) video, SE (selective enhancement) function is adopted to enhance the subject quality of the region of interest (ROI). However, it has the problem of excessive bit-rate increase in the enhancement layer. We present a new rectangular region-based SE (RSE) algorithm to significantly reduce the overhead bits resulting from the standard SE. The proposed RSE is based on two new algorithms. The first is to apply the SE function to a rectangular region. By doing so, we can reduce the required bits for describing the selectively enhanced region. The second is to use constrained bit-plane scanning (CBS) to encode bit-planes of the enhancement layer. By using CBS, we can efficiently encode the ALL-ZERO symbols that are generated by applying the SE. It Is shown by simulation that the proposed RSE can provide a good visual quality for the selected rectangular region with significantly reduced overhead bits.

• Journal of the Korea Society of Computer and Information
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• v.16 no.3
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• pp.27-34
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• 2011

In this paper, the novel approach for image contrast enhancement is introduced. The method is based on the unsharp mask and directional information of images. Since the unsharp mask techniques give better visual quality than the conventional sharpening mask, there are much works on image enhancement using unsharp masks. The proposed algorithm decomposes the image to several blocks and extracts directional information using DCT. From the geometric properties of the block, each block is labeled as appropriate type and processed by adaptive unsharp mask. The masking process is skipped at the flat area to reduce the noise artifact, but at the texture and edge area, the adaptive unsharp mask is applied to enhance the image contrast based on the edge direction. Experiments show that the proposed algorithm produces the contrast enhanced images with superior visual quality, suppressing the noise effects and enhancing edge at the same time.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.7 s.110
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• pp.648-658
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• 2006

We propose a thin frequency selective surface(FSS) superstrate etched on a substrate for dual-band directivity enhancement, and present a design method of the superstrate. In the proposed new design, two FSS arrays with the same periodicity, but with different alignments are placed above and below a thin dielectric layer to overcome the problem of conventional superstrates for dual band directivity enhancements. Based on the unit-cell simulation, several important parameters that characterize the thin FSS superstrate are investigated, and the procedure for designing such a superstrate is described. We compare the resonant frequencies and the qualify factors of the unit cell with those of three FSS antenna composites with different quality factors, and identify the quality factors which support similar directivity enhancement at the dual-band directivity enhancement. It was found that there is an optimum FSS array size of a superstrate to enhance the directivity most efficiently. Measured results for a fabricated superstrate show a good agreement with the simulated ones.

• The Journal of the Acoustical Society of Korea
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• v.41 no.1
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• pp.38-44
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• 2022

Speech enhancement is performed to improve intelligibility and quality of the noise-corrupted speech. In this paper, speech enhancement performance was compared using different loss functions in time and frequency domains. This study proposes a combination of loss functions to utilize advantage of each domain by considering both the details of spectrum and the speech waveform. In our study, Scale Invariant-Source to Noise Ratio (SI-SNR) is used for the time domain loss function, and Mean Squared Error (MSE) is used for the frequency domain, which is calculated over the complex-valued spectrum and magnitude spectrum. The phase loss is obtained using the sin function. Speech enhancement result is evaluated using Source-to-Distortion Ratio (SDR), Perceptual Evaluation of Speech Quality (PESQ), and Short-Time Objective Intelligibility (STOI). In order to confirm the result of speech enhancement, resulting spectrograms are also compared. The experimental results over the TIMIT database show the highest performance when using combination of SI-SNR and magnitude loss functions.

• Journal of Korean Academy of Nursing
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• v.40 no.5
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• pp.724-735
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• 2010

Purpose: In this study a cognitive enhancement group training program of 10 sessions was provided for communitydwelling elders and the effects on cognitive function, depression and quality of life were tested. Methods: A quasi-experimental study using a nonequivalent control group, pre-post design was used. The participants were 87 elders whose cognitive function was within the normal range. Of these elders, 45 were assigned to the experimental group and 42 to the control group. The intervention was conducted once a week for 10 weeks. Chi-square test, t-test, paired t-test, Wilcoxon rank sum test and Wilcoxon signed rank test were used to analyze the data. Results: After the program, the cognitive function (t=-2.85, p=.006), depression (z=2.82, p=.005) and quality of life (t=2.79, p=.007) of the experimental group was significantly better than those of the control group. Especially, immediate recall (z=2.45, p=.014) and concentration (z=2.58, p=.010) in the subcategory of cognitive function were significantly better than that of the control group. Conclusion: The findings indicate that the cognitive enhancement group training program was effective in enhancing the cognitive function, depression and quality of life for elders and could therefore be considered as a positive program for emotional and cognitive support for community-dwelling elders.

• Journal of Korea Multimedia Society
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• v.17 no.8
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• pp.923-936
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• 2014

Images can be contaminated with different types of noise, for different reasons. The neighborhood averaging and smoothing by image averaging are the classical image processing techniques for noise removal. The classical spatial filtering refers to the aggregate of pixels composing an image and operating directly on these pixels. To reduce or remove effectively noise in image sequences, it usually needs to use noise reduction filter based on space or time domain such as method of spatial or temporal filter. However, the method of spatial filter can generally cause that signals of objects as the target are also blurred. In this paper, we propose temporal filter using the piece-wise quadratic function model and enhancement algorithm of image quality for the performance improvement of target detection and tracking by heterogeneous noise reduction. Image tracking simulation that utilizes real IIR(Imaging Infra-Red) images is employed to evaluate the performance of the proposed image processing algorithm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1479-1486
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• 2008

Recently, the number of applicants for the engineering college is gradually decreased all over the nation. Additionally, the concerns of fall of freshman mathematical ability are raised due to the incomplete high school education. Therefore, the local universities endeavor in order to improve the quality of mathematics education, and study the countermeasure against the crisis. As part of these efforts, Sang-Myung University founds the innovation center for engineering education. The center derives several ideas in order to enhance the mathematics education quality. In this paper, the enhancement plans for the mathematics education in Sang-Myung University are proposed. Results in this paper will be helpful for other university to enhance the mathematics education as reference materials.

• Journal of Korean Society of Rural Planning
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• v.23 no.3
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• pp.61-72
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• 2017

The purpose of this paper is to estimate consumer's satisfaction by purchasing farmer's processed food. So, this paper surveyed consumers which have purchased Korean traditional soybean paste products, by reason of limiting research objects among lots of farmer's processed food. A survey of 220 consumers was carried out on September and October 2016. For this matters, this paper used multiple linear regression model(included LOG-LIN model) and, set up 1 dependent and 11 independent variables. As the analysis results, we could find out that consumer's satisfaction was affected by 6 variables(price, taste, ease of cooking, confidence of product information, social awareness and perceived 6th industrialization). Among these variables, the strongest variable was "social awareness", and the second was "perceived 6th industrialization". This paper also estimated the rate of change that a dependent variable was affected by independent variables. As the results, this paper found out that "perceived 6th industrialization" had the highest rate of change(5.8%) and the second was "social awareness"(5.6%). This paper proposed 7 implications of Korean traditional soybean paste. Those were the proper price policy and quality value's promotion, quality Improvement and confidence enhancement, development of products for consumer's convenience, enhancement of social awareness, enhancement of politic management about 6th industrialization and accessibility of purchasing information.