• Applied Chemistry for Engineering
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• v.34 no.1
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• pp.64-68
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• 2023

The salt concentration process in electrodialysis, which uses electrical energy to enhance ion concentrations in an aqueous electrolyte solution, has been studied on the transfer phenomenon of ions and water molecules over the ion exchange membrane. In this paper, we investigated various parameters for limiting concentration of electrolyte solution and the electroosmosis phenomenon in an electrodialysis system by varying salt concentration of electrolyte solution. The electroosmotic water transport was analyzed by measuring the ions and water fluxes in electrolyte solutions having two different NaCl concentrations (NaCl 2M/4M), and concentration change was observed for various volume ratios of the diluted reservoir to the concentration one As a result, it was found that the higher concentration of the aqueous electrolyte solution, the lower electroosmosis, and the higher volume ratio led to a higher concentration in the dilute reservoir, so the limiting concentration was enhanced and the specific energy consumption decreased.

• Convergence Security Journal
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• v.23 no.1
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• pp.117-123
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• 2023

To detect advanced ransomware attacks with machine learning-based models, the classification model must train learning data with high-dimensional feature space. And in this case, a 'curse of dimension' phenomenon is likely to occur. Therefore, dimensionality reduction of features must be preceded in order to increase the accuracy of the learning model and improve the execution speed while avoiding the 'curse of dimension' phenomenon. In this paper, we conducted classification of ransomware by applying three machine learning models and two feature extraction techniques to two datasets with extremely different dimensions of feature space. As a result of the experiment, the feature dimensionality reduction techniques did not significantly affect the performance improvement in binary classification, and it was the same even when the dimension of featurespace was small in multi-class clasification. However, when the dataset had high-dimensional feature space, LDA(Linear Discriminant Analysis) showed quite excellent performance.

• Journal of the Korea Convergence Society
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• v.12 no.3
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• pp.165-176
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• 2021

Recently, interest in home training and changes in lifestyle are expanding the market in the healthcare field, and high value-added fashion products reflecting the dumbbell economy phenomenon are being released. This study had the following objectives: to investigate the possibility of developing a fashion item that can be applied to the dumbbell economy phenomenon; to develop the UI/UX of a smartphone application for beginners who wish to work out their upper and lower bodies regardless of time and space; and to create a wearable customized smart athleisure fashion device. First, the study identified factors related to exercise methods, breathing techniques, and range of exercises for beginners by investigating the postures of workouts of the upper and lower bodies by angles. Based on the results, the study collected empirical data through a user needs analysis from muscle strengthening exercise experts to verify the significance of the study and use as fundamental data. Second, the study developed the UI/UX of a smartphone application with three different contents: counting, suggesting exercise postures, and providing exercise calendars. Further, the study analyzed necessary user-centered concepts and characteristics in terms of design and technology and developed a wearable customized smart athleisure fashion device based on the results.

• Journal of Industrial Convergence
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• v.21 no.2
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• pp.125-131
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• 2023

In this paper, research was conducted to solve the problem of reducing the dimming level and flicker that occurs in the visible light communication system. Visible light communication is a convergence technology that provides both communication and lighting, and must satisfy not only communication performance but also lighting performance. However, since the existing data transmission method transmits without considering the transmission data sequence, it reduces the dimming level and causes a flicker phenomenon. To solve this problem, in this paper, the Dimming Improvement and Flicker Reduction Mapping technique was studied. Existing systems simply transmitted data of '0' and '1', but in this system, original data transmission channels and DIFR (Dimming Improvement and Flicker Reduction) transmission channels are assigned to RGB channels. Original data is allocated to the R channel and original data or inverse original data is allocated to the DIFR-G channel, and the DIFR-B channel maintains the maximum dimming level by transmitting through the logical operation of the R channel and the G channel. At the same time, the flicker phenomenon is prevented by preventing continuous occurrence of 'OFF' patterns. Through this, we proposed an adaptive data allocation algorithm that can faithfully play a role as a light as well as a communication function.

• Journal of Digital Convergence
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• v.19 no.1
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• pp.335-342
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• 2021

Launched in 2017, Loewe Craft Prize is now establishing itself as the most prestigious craft contest in the world. In this study, we noted the background behind the Loewe Craft Prize, which started with a luxury brand, developing into the best contest covering all crafts in a short period of four years. In crafts with various contests around the world, Loewe Craft Prize's interest in craft, which has no limitations on genre diversity and materials, is a result of no contest. This is possible by forming and developing a complex contest, which is differentiated from the existing single-material contest and the distinct values of the crafts possessed by Loewe Craft Prize. In this study, the background of this result was the convergence of materials, the fusion of tradition and modernity, and the convergence of science and crafts, and the tendency of writers and the flow of modern crafts through their works. We also want to find out how the meaning of the expansion of the craft genre affects modern crafts.

• Journal of Digital Convergence
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• v.19 no.7
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• pp.303-312
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• 2021

The Possibility of contemporary ceramics creation through the convergence of materials In modern society, the creation of new values through convergence is emerging as a new trend. Modern potters are also trying to expand a new concept of art by combining various materials with other media. In craft, materials are essential and the most fundamental elements of expression. Therefore, from the viewpoints of various fusions, the significance of the fusion between materials will be explored. Also, focusing on paperclay, which is the most likely to be transformed material, we explore creative possibilities in the process of producing materials and works. Chapter 2 presents the concept and significance of fusion and material properties, and introduce the trend of fusion used in contemporary ceramics as material expression. In Chapters 3 and 4, characteristics and possibilities are examined through paper clay production and presentation based on the structure of the previous analysis. As a result, it is intended to present the direction that modern ceramics should pursue through a fusion phenomenon such as bonding between materials in the future and to explore potential possibilities for development.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.5
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• pp.1-13
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• 2020

The empty houses' problem is important in the local revitalization and local sustainability, and these phenomenon caused by various factors of the region. The population and housing census data are the most effective data available to study this phenomenon by small regions. In this study, logistic regression and multiple regression analysis were performed to understand the effects of population, household, and housing characteristics on empty houses using population and housing census data. Also, the scale and direction of the effect of each characteristic in large cities, small cities, and rural areas were compared. As results, there was a slight difference between cities and province regions in the district and housing characteristic variables. In the comparison of Eup-Myeon-Dong, the affected variables were different in the Dong and Myeon areas. The significance of this study is to examine the effect of the characteristics of population and housing on the vacant houses and to confirm that the factors affecting different regions.

• Journal of Korean Society of Archives and Records Management
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• v.3 no.1
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• pp.141-158
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• 2003

This paper examines new phenomenon and transformation that arise from the expansion of knowledge-based economy, envisions the meaning of e-government through comparing traditional administration with new governance, formulates the e-government model, and presents a direction for next e-government for the conclusion. These new phenomenon include a transformation to product and service convergence model, cyber sovereignty dilemma, privacy and information security threats, and various others. Also, there is a gradual transformation from government-oriented administrative approach to a new governance model that strengthens the role of NGO. And, e-government must work together to realize this new governance ideology. New e-government must be transformed where government and citizens can implement and manage e-government together. Therefore, expanding applications of Public Key Infrastructure (PKI) technologies, promotion of e-Democracy, and improvement of user interface to improve usability must be emphasized.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.5
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• pp.419-425
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• 2016

A powder spreading phenomenon is one of disadvantageous characteristics of the powder bed fusion process using electron beams. The powder spreading phenomenon can be controlled using a pre-heating process of metallic powders. The aim of this paper was to investigate the preheating process of Stellite21 powder using electron beams. Powder spreading experiments were performed to examine the influence of process parameters on the spreading behaviors of Stellite21 powder. Powder heating experiments were carried to investigate the effects of the focusing current of the electron beam on the quality of the heated region. Using the results of the powder spreading and heating experiments, an appropriate combination of process parameters was obtained. The pre-heating experiment of Stellite21 was performed using the estimated combination of process parameters. The results of preheating experiments showed that the preheated Stelllite21 layer with desired characteristics can be created when the estimated combination of process parameters is applied.

• Journal of Biomedical Engineering Research
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• v.14 no.2
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• pp.155-162
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• 1993

The human's biomechanical structure keeps an optimal state by adapting the original biomechanical structure according to a change in the physical environment. This phenomenon is believed to be the main cause of loosening of the total hip replacement which is used widely in these days. In this study the bone density change due to artificial hip joint, which is generally believed as bone-remodeling, was investigated by the finite element method. For this, 2-D FEM models with 4 nodal point elements were constructed for intact and implanted cases. The density was calculated by comparing the relative amounts of effective stress for these two cases. In this way, calculated new density values were used in the next step as input values and this procedure repeated until convergence was obtained. Severe density change was detected at the femoral cortex of the proximal-medial side as expected. Moreover, following surprising result was found from this analysis. Titanium alloy prosthesis showed less density change compared to stainless steel prosthesis at earlier stage, however, almost same amount of the density change was detected at final stage. It was also found that other design parameters could not significantly affect its density change.