• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.1
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• pp.374-395
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• 2017

Users quite often experience volatile channel conditions which negatively influence multimedia transmission. HTTP adaptive streaming has emerged as a new promising technology where the video quality can be adjusted to variable network conditions. Nevertheless, the new technology does not remain without drawbacks. As it has been observed, multiple video players sharing the same network link have often problems with achieving good efficiency and stability of play-out due to a mutual interference and competition among video players. Our investigation indicates that there may be another cause for under-performance of the streamed video. In an emulated environment, we implemented three algorithms of adaptive video play-out based on bandwidth or buffer assessment. As we show, traffic generated by players employing the same or similar play-out strategies is positively correlated and synchronised (clustered), whereas traffic originated from different play-out strategies shows negative or no correlations. However, when some of the parameters of the play-out strategies are randomised, the correlation and synchronisation diminish what has a positive impact on the smoothness of the traffic and on the video quality perceived by end users. Our research shows that non-correlated traffic flows generated by play-out strategies improve efficiency and stability of streamed adaptive video.

• The Korean Journal of Food And Nutrition
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• v.34 no.3
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• pp.272-288
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• 2021

Mealworm is the most widely used edible insect in Korean traditional food. In this study, the quality characteristics and antioxidant activity of Garaedduk containing different proportions of powdered mealworm (0%, 3%, 6%, 9%, and 12%) were evaluated in order to enhance the utilization of mealworm. The results revealed that moisture content decreased while pH and starch elution increased, with increasing amount of mealworm. Furthermore, the amount of total amino acids, essential amino acids, and non-essential amino acids increased with increasing amount of mealworm. Regarding chromaticity, the L value decreased while the a and b values increased as the amount of mealworm increased. The addition of 6% mealworm showed slight differences in the pore size and surface smoothness as compared to plain Garaedduk. Texture, hardness, chewiness, and gumminess increased, but cohesiveness decreased with increasing amount of mealworm. The preference test evaluating the appearance, flavor, taste, texture, and overall preference showed that 6% mealworm additive group had the highest preference. In addition, antioxidant activity of the newly developed Garaedduk increased with increasing amount of mealworm. In conclusion, Garaedduk enriched with 6% mealworm showed promising results for developing rice cake with improved nutrition and antioxidant activity and excellent overall preference and quality.

• International Journal of Computer Science & Network Security
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• v.22 no.5
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• pp.234-244
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• 2022

Tourism products involve the transfer of money that is flowing to countries with partners or borders, which do not possess any relations surrounding their business environment. Suitable platforms must be generated by the tourism industry, which are beneficial to users when their demands are satisfied based on financial, technology, knowledge, and industry matters. Intermediaries are applied to alleviate different problems that are related to the non-fulfilment of contracts of existing users and service providers who are offering their services and represent a reliable third party. However, it is significant that intermediaries must be reliable when charges are incurred for any possible commission. Cryptocurrencies rely on blockchain technology to provide smoothness in money interchange without the need for reliable third parties. This interchange allows an increasing number of different new forms, which are related to different customer-to-customer transactions. The study attempts to provide an appropriate answer to the main research question, which is: 'Will the widespread adoption of cryptocurrencies bring new types of customer-to-customer markets from a technological, organizational, and environmental perspective?'.

• Steel and Composite Structures
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• v.47 no.5
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• pp.569-585
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• 2023

This paper proposes an efficient approach for the structural topology optimization of bi-directional functionally graded structures by incorporating popular radial basis functions (RBFs) into an implicit level set (ILS) method. Compared to traditional element density-based methods, a level set (LS) description of material boundaries produces a smoother boundary description of the design. The paper develops RBF implicit modeling with multiquadric (MQ) splines, thin-plate spline (TPS), exponential spline (ES), and Gaussians (GS) to define the ILS function with high accuracy and smoothness. The optimization problem is formulated by considering RBF-based nodal densities as design variables and minimizing the compliance objective function. A LS-RBF optimization method is proposed to transform a Hamilton-Jacobi partial differential equation (PDE) into a system of coupled non-linear ordinary differential equations (ODEs) over the entire design domain using a collocation formulation of the method of lines design variables. The paper presents detailed mathematical expressions for BiDFG beams topology optimization with two different material models: continuum functionally graded (CFG) and mechanical functionally graded (MFG). Several numerical examples are presented to verify the method's efficiency, reliability, and success in accuracy, convergence speed, and insensitivity to initial designs in the topology optimization of two-dimensional (2D) structures. Overall, the paper presents a novel and efficient approach to topology optimization that can handle bi-directional functionally graded structures with complex geometries.

• The Korean Journal of Applied Statistics
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• v.31 no.6
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• pp.677-692
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• 2018

The total fertility rate of Korea was 1.05 in 2017, showing a return to the 1.08 level in the year 2005. 1.05 is a very low fertility level that is far from replacement level fertility or safety zone 1.5. The number may indicate a low fertility trap. It is therefore important to predict fertility than at any other time. In the meantime, we have predicted the age-specific fertility rate and total fertility rate by various statistical methods. When the data trend is disconnected or fluctuating, it applied a nonparametric method applying the smoothness and weight. In addition, the Bayesian method of using the pre-distribution of fertility rates in advanced countries with reference to the three-stage transition phenomenon have been applied. This paper examines which method is reasonable in terms of precision and feasibility by applying estimation, forecasting, and comparing the results of the recent variability of the Korean fertility rate with parametric, non-parametric and Bayesian methods. The results of the analysis showed that the total fertility rate was in the order of KOSTAT's total fertility rate, Bayesian, parametric and non-parametric method outcomes. Given the level of TFR 1.05 in 2017, the predicted total fertility rate derived from the parametric and nonparametric models is most reasonable. In addition, if a fertility rate data is highly complete and a quality is good, the parametric model approach is superior to other methods in terms of parameter estimation, calculation efficiency and goodness-of-fit.

• Journal of Biomedical Engineering Research
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• v.32 no.3
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• pp.237-244
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• 2011

In this paper, a feature-based registration technique is proposed for pre-contrast and post-contrast lung CT images. It utilizes three dimensional(3-D) features with their descriptors and estimates feature correspondences by nearest neighborhood matching in the feature space. We design a transformation model between the input image pairs using a free form deformation(FFD) which is based on B-splines. Registration is achieved by minimizing an energy function incorporating the smoothness of FFD and the correspondence information through a non-linear gradient conjugate method. To deal with outliers in feature matching, our energy model integrates a robust estimator which discards outliers effectively by iteratively reducing a radius of confidence in the minimization process. Performance evaluation was carried out in terms of accuracy and efficiency using seven pairs of lung CT images of clinical practice. For a quantitative assessment, a radiologist specialized in thorax manually placed landmarks on each CT image pair. In comparative evaluation to a conventional feature-based registration method, our algorithm showed improved performances in both accuracy and efficiency.

• Journal of Fashion Business
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• v.10 no.1
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• pp.120-131
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• 2006

Recently, it has been reported that chemical hair coloring can cause allergic reactions, the toxicity issue of chemical hair color was issued. Therefore, there is an increasing interest in the hair coloration technique using non-toxic and bio-compatible hair color gotten from natural resource. In this study, the possibility using fermented Indigo as natural hair coloring agent was investigated. Bleached hair samples were dyed using Indigo, and the effect of dyeing frequency, the physical change after dyeing, color, surface and cross-section characteristics, and tensile property were also studied. In addition, the protection property of cationic detergent finishing on damaged hair samples were also studied. The following conclusions are made; 1. While bleached hair samples with low value showed the negligible effect of repeated dyeing, bleached hair samples with high value showed the good effect of repeated dyeing. 2. Hair sample dyed with Indigo showed a high light-fastness, however, tensile strength and elongation showed very low values (high damage on hair sample). 3. Cationic detergent finishing did not affect on the colorfastness because of decoloration after dyeing, however, it increased the smoothness of hair sample, and therefore, can use as protectant of damaged hair. 4. Hair scale was damaged after dyeing. It seemed that the alkali, potassium carbonate, increased pH of dyeing bath to 11, as a result, the hair was swollen, weaken, and dissolved on the prolonged dyeing time. Dyed hair sample became stiff and fine. 5. The color difference was 4.62 (a high fastness value) in the test of sunlight exposure, shampoo, cationic detergent finishing, and acid perspiration fastness.

• The Journal of the Korea Contents Association
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• v.15 no.2
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• pp.21-30
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• 2015

Image coding based on mixed raster content model generates don't care regions (DCR) in foreground and background layers, and its overall coding performance is greatly affected by region filling methods for DCRs. Most conventional methods for DCR filling fail in utilizing the local signal properties in hole regions and thus the high frequency components in non-DCR regions are reflected into DCR after signal filling. In addition, further high frequency components are induced to the filled signal because of signal discontinuities in the boundary of DCR. To solve this problem, a new DCR filling algorithm using the priority-based adaptive region growing is proposed in this paper. The proposed method uses the watershed algorithm and the flooding priority of each pixel for region filling is determined from the degree of smoothness in the neighborhood area. By growing the filled region into DCR based on the computed priority, the expansion of high-textured area can be minimized which can improve the overall coding performance. Experimental results show that the proposed method outperforms conventional algorithms.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.10
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• pp.123-131
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• 1999

In this paper, we proposed stereo matching algorithm by dynamic programming with edges emphasized. Existing algorithms show blur generally at depth discontinuities owing to smoothness constraint and non-existence of matching pixel in occlusion regions. Also it accompanies matching error by lackness of matching information in the untextured regions. This paper defines new cost function to make up for the problems occurred to existing algorithms. It is possible through deriving matching of edges in left and right images to be carried out between edge regions anf deriving that in the other regions to be peformed between the other regions. In case of the possibility that edges can be Produced in a large amount, matching between edge information adds weight to cost function in proportion to Path distance. Proposed algorithm was applied to various images obtained by convergent camera model as well as parallel camera model. As the result, proposed algorithm showed improved performance in the aspect of matching error and processing in the occlusion regions compared to existing algorithms. Also it could improve blur especially in discontinuity regions.

• Journal of the Korean Society of Clothing and Textiles
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• v.31 no.1 s.160
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• pp.57-67
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• 2007

The purpose of this study is to find out the better washing condition, especially on detergent contents to satisfy the consumer's concern on fabric hand using Drum Type Washer. The hand and preference of washed fabrics by various detergent contents were analyzed through subjective evaluation using questionnaire method in dry and wet state. Wine rank's semantic differential scale questions were developed with 27 kinds of adjective pairs and seven rank's scale questions were to evaluate preference of washed fabrics oil holistic touch, washing and rinsing effect and purchase intention of detergent. Group of trained panelists and untrained women panelists of $30{\sim}40$ years old were participated. The factors affecting consumer's taste for the washed fabrics were analyzed by SPSS 12.0. Smoothness showed relatively higher correlation with preference of washed fabrics on holistic touch, washing and rinsing effect and purchase intention of detergent. There were significant differences in preference of washed fabrics on holistic touch, washing and rinsing effect and purchase intention of detergent by detergent contents when tested in wet state. Fabrics washed with detergents of non-zeolite were appeared to be the preferred ones.