• Applied Chemistry for Engineering
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• v.35 no.2
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• pp.148-153
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• 2024

In this study, a methodology for evaluating impact strength in rollable devices was developed, focusing on measuring impact strength and evaluating rolling and unrolling durability simultaneously, with findings reported from tests on a real demonstration unit. The study utilized a flexible and rollable polyimide (PI) substrate for the evaluations. The chosen parameters for this methodology were a flat-type impactor, weights of 300 g, 500 g, and 1000 g, a rolling shaft ranging from 30 R to 5 R, and the positioning of the impactor. The results revealed that the difference in defect rates when comparing the 300 g and 500 g weights was minimal. However, the adoption of a 1000 g weight markedly increased the defect count due to damage to the PI film's surface. Furthermore, an uptick in rolling and unrolling cycles led to more pronounced surface scratches on the PI film. These methods and findings are poised to make a substantial contribution towards refining reliability testing for a wide array of rollable device applications, including smartphones, watches, pads, and wearable technology.

• Clean Technology
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• v.25 no.4
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• pp.283-288
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• 2019

Monodisperse microparticles has been particularly enabling for various applications in the encapsulation and delivery of pharmaceutical agents. The microfluidic devices are attractive candidates to produce highly uniform droplets that serve as templates to form monodisperse microparticles. The microfluidic devices that have micro-scale channel allow precise control of the balance between surface tension and viscous forces in two-phase flows. One of its essential abilities is to generate highly monodisperse droplets. In this paper, a microfluidic approach for preparing monodisperse polycaprolactone (PCL) microparticles is presented. The microfluidic devices that have a flow-focusing generator are manufactured by soft-lithography using polydimethylsiloxane (PDMS). The crucial factors in the droplet generation are the controllability of size and monodispersity of the microdroplets. For this, the volumetric flow rates of the dispersed phase of oil solution and the continuous phase of water to generate monodisperse droplets are optimized. As a result, the optimal flow condition for droplet dripping region that is able to generate uniform droplet is found. Furthermore, the droplets containing PCL polymer by solvent evaporation after collection of droplet from device is solidified to generate the microparticle. The particle size can be controlled by tuning the flow rate and the size of the microchannel. The monodispersity of the PCL particles is measured by a coefficient of variation (CV) below 5%.

• Science of Emotion and Sensibility
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• v.22 no.3
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• pp.35-46
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• 2019

Artificial intelligence (AI) technology has been evolving to recognize and learn the languages, voice tones, and facial expressions of users so that they can respond to users' emotions in various contexts. Many AI-based services of particular importance in communications with users provide emotional interaction. However, research on nonverbal interaction as a means of expressing emotion in the AI system is still insufficient. We studied the effect of lighting on users' emotional interaction with an AI device, focusing on color and flickering motion. The AI device used in this study expresses emotions with six colors of light (red, yellow, green, blue, purple, and white) and with a three-level flickering effect (high, middle, and low velocity). We studied the responses of 50 men and women in their 20s and 30s to the emotions expressed by the light colors and flickering effects of the AI device. We found that each light color represented an emotion that was largely similar to the user's emotional image shown in a previous color-sensibility study. The rate of flickering of the lights produced changes in emotional arousal and balance. The change in arousal patterns produced similar intensities of all colors. On the other hand, changes in balance patterns were somewhat related to the emotional image in the previous color-sensibility study, but the colors were different. As AI systems and devices are becoming more diverse, our findings are expected to contribute to designing the users emotional with AI devices through lighting.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.703-710
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• 2017

Third-generation (3G) devicesare next-generation devices that allow the use of intelligent services and applications through the Internet of Things (IoT). As the market forexisting smart devices like smartphones and tablet PCs enters the stage of stagnation, the world is now focusing on 3G devices, parts, and services. This study is intended to measure the user's benefits from the various attributes of 3G devices by applying an economic valuation method. For this purpose, the conjoint analysis method was applied, which is one of the representative valuation methods. To apply conjoint analysis, the following attributes of 3G devicesare considered: mode of use, power efficiency, life care, and price. By applying the mixed logit model, the marginal willingness-to-pay(WTP) for each attribute was derived. The results are statistically significant. Respondents showed a high preference or complete flexibility in the mode of use attribute. And they were also found to have WTP for improvements in the life care attribute. The implications and quantitative results of this study are expected to be useful for policies and strategies in the 3G device market.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.144-149
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• 2020

Bubble reduction devices are intended to solve problems related to the quantitative supply of oil. Therefore, in this study, numerical analysis was conducted to verify the flow characteristics of bubble particles during the operation of a bubble reduction device. As a result of the basic analysis, the area where the rise and fall of bubbles were most active was found, and numerical calculations were performed focusing on the points. Before the numerical calculations, a non-dimensional derivation was performed to secure homogeneity among the variables. Based on the data obtained from non-dimension derivation, 25 variable conditions for each particle size and fluid velocity were set. Through separate calculations, the equation for bubble rise and fall was derived. By calculating the ratio of drag and buoyancy for each variable, if the drag force acting on the bubble was greater than buoyancy, the bubble falls, and bubbles are not reduced. If the buoyancy is larger than drag, the bubble rises, and the bubble is reduced. Through the analysis, the rise and fall of the bubble were confirmed, and the results were consistent with the separate numerical calculations.

• The Korean Journal of Archival Studies
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• no.70
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• pp.157-187
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• 2021

Broadcasting and audiovisuals are the easiest audiovisuals to access in everyday life and are shared through the media by recording the times. Overseas, independent broadcasting and audiovisual archives are already in operation under the legal system. As the domestic broadcasting and audiovisual industries continue to grow in size and are drawing global attention, the establishment and operation of public broadcasting and audiovisual archives need to be discussed in more detail. In particular, it is clear that the legal device is a task that must be preceded as the basis for the establishment of public broadcasting and audiovisual archives. To this end, this study first looked at the Digital Archive Center, which was operated in the 2000s. In addition, the cause of the dismantling of the Digital Archive Center was considered as the absence of a legal device, and the case of the Institut national de l'audiovisuel(INA), which has been operating on a legal basis for a long time, was investigated. INA is a representative example of implementing a lead-based system in the broadcasting and audiovisual fields, and has been introduced several times through previous studies, but tends to be focused on user services. Therefore, in this study, the analysis was focused on legal factors supporting the operation of INA. Finally, in order to realize the Public Broadcasting and Audiovisual Archive discussed in the previous study, I would like to suggest a legal device for the establishment of Public Broadcasting and Audiovisual Archive in Korea.

• Informatization Policy
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• v.29 no.2
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• pp.106-126
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• 2022

The digital divide issue is re-emerging in step with the rapid progress of digital transformation. Recently, the discussion of the digital divide is expanding to the point that the difference in digital access and use competency deepens economic and social inequality and discrimination. Notably, the phenomenon of the exclusion and alienation of the elderly from society is a serious matter to be addressed. Accordingly, this research was conducted to provide practical help in minimizing the digital divide through its understanding among the elderly. To this end, both the accomplished capital accumulated and experienced in the course of life and their attitudes toward technology in relation to digital competence capital by the elderly were examined in three dimensions. This analysis was conducted using the results of the '2020 The Report on the Digital Divide'. The target group of the analysis comprised 653 seniors aged 65 and above. As a result of the analysis, digital competence capital among the elderly was affected by both various types of accomplished capital such as educational, income, social, and emotional capital and digital device use attitude. Based on this, this study proposed measures to bridge the digital divide among the elderly.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.951-953
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• 2015

Learning for thinking says the behavior of the organism changes as a result of practice or experience. It is very difficult to identify focusing ability objectively when students study. But, brain of the body is not so. EEG signal means continuously electric records of brain potential variation between two points on the scalp when brain activities take place. In types of EEG, there are delta(0~4Hz), theta(4~8Hz), alpha(8~13Hz), beta(13~30Hz) and gamma waves(30~50Hz). SMR waves and Mid-beta waves appear when focused for studying. Part for the most influence on concentrating reported that Mid-beta waves. In relation to brain activities, EEG has been actively researched for evaluating brain focus index system during learning and study. So, By using Biopac system for this study, measured brain wave was converted into FFT for extracting Mid-beta domain signals that are related to learning after giving focus invoked subjects to a small number of people. When concentrating, we measured the change in the power of the Mid-beta frequency domain and presented a correlation. Based on these results, we analyzed whether students are concentrated objectively on learning or not. and hope to offer more efficient learning method.

• Journal of the Microelectronics and Packaging Society
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• v.16 no.4
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• pp.33-39
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• 2009

A microlens array (MLA) was developed based on the wet-etched quartz substrate and coating of UV adhesive on the substrate for maskless lithography application. The developed MLA has the focal length of ${\sim}45\;{\mu}m$ and the spot size of ${\sim}1\;{\mu}m$. The spot size of the focused beam passing through the MLA was detected by CCD camera, and its intensity was monitored by beam profiler. Uniform spots with nearly identical intensities were observed on the focal plane when a beam passes through the fabricated MLA. The focal length was varied depending on thickness of the coated UV adhesive. The thicker the thickness of the UV adhesive was, the shorter the focal length of the MLA was. With a general mask aligner, UV beam focusing was tested onto photoresist (PR). The beams were well focused onto PR when UV passes through the MLA. Depending on the variable distances from the MLA, beam sizes onto PR were controlled. Even at high temperature for a long time, the performances of the MLA were not changed.

• Cartoon and Animation Studies
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• s.35
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• pp.347-374
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• 2014

The aim of this article is to consider the future of industrialization of Augmented Reality contents focusing on cinematic imagination of films that used Augmented Reality techniques and artistic imagination of Augmented Reality Arts in the 21st century. The film showing future technology through cinematic imagination plays an role in the presentation of future vision important. Augmented Reality Arts show the big picture of future arts, future aspect of society, and future culture by using technically possible present technology. I classified the researched films according to Augmented Reality technique. It is expected that Gesture Recognition will develop with transparent display device techniques, Hologram techniques will be changed into individualized communication styles, Biometrics will be able to evolve into multi-Biometrics, and Wearable Computer will develop in the aspect of physical body augmentation and then industrialize. In Augmented Reality Arts, it seems that the various utilization of avatar will be related to Hologram, the utilization of the physiological phenomenon of the human body will be related to Biometrics, the mixture of reality and virtual reality will utilize display devices through Gesture Recognition, and a new experiment of HMD(Head-Mounted Display) will industrialize with the diversification of Wearable Computer. Augmented Reality contents created through the imagination and representation in the films and arts take a role in helping human life, and, at the same time, show the future image industrialized in the way of combination between human and environment without a medium.