• Smart Structures and Systems
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• v.22 no.2
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• pp.161-166
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• 2018

In the last decade, there has been an exponential increase of scientific interest in smart additive manufacturing (AM) technology. Among the different AM techniques, one of the most commonly applied processes is digital light processing (DLP). DLP uses a digital projector screen to flash an ultraviolet light which cures photopolymer resins. The resin is cured to form a solid to produce parts with precise high dimensional accuracy. During the curing process, there are several process parameters that need to be optimized. Among these, the exposure time affects the quality of the 3D printed specimen such as mechanical strength and dimensional accuracy. This study examines optimal exposure times and their impact on printed part. It was found that there is optimal exposure time for printed part to have appropriate mechanical strength and accurate dimensions. The gel fraction and TGA test results confirmed that the improvement of mechanical properties with the increasing UV exposure time was due to the increase of crosslinked network formation with UV exposure time in acrylic resins. In addition, gel fraction and thermogravimetric analysis were employed to microscopically investigate how this process parameter impacts mechanical performance.

• International journal of advanced smart convergence
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• v.5 no.3
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• pp.66-71
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• 2016

Smart building gate security control system using smartphone integrated with near field communication (NFC) has become part of daily life usage these days. The technology change in replacing RF NFC device using visible light communication technology based approach growing faster in recent days. This paper propose a design and development of gate security control system using color code based user authentication ID generation as part of an intelligent access control system to control automatic door open and close. In this approach gate security access control use the recent visible light communication technology trends to transfer the user specific authentication code to door access control system using color code on smartphone screen. Using a camera in the door access control system (ACS), color codes on smartphone screens are detected and matched to the database of authenticated user to open the door automatically in gate security system. We measure the visual light communication technology efficiency as a part of the research and the experiments have revealed that more than 95% users authenticated correctly at the suggested experiment environment on gate security control system.

• BMB Reports
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• v.43 no.11
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• pp.750-755
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• 2010

Crude Orostachys japonicus polysaccharide extract (OJP) was prepared by hot steam extraction. Polysaccharides (OJPI) were separated from OJP by gel filtration chromatography and phenol-sulfuric acid assay. The average molecular weight of the OJPI was 30-50 kDa. The anti-proliferative effect of OJPI on HT-29 human colon cancer cells was investigated via morphology study, cell viability assay, apoptosis assay, cell cycle analysis, and cDNA microarray. OJPI inhibited proliferation and growth of HT29 cells and also stimulated apoptosis in a dose- and time-dependent manner. In cell cycle analysis, treatment with OJPI resulted in a marked increase of cells in the G0 (sub G1) and G2/M phases. To screen for genes involved in the induction of cell cycle arrest and apoptosis, the gene expression profiles of HT-29 cells treated with OJPI were examined by cDNA microarray, revealing that a number of genes were up- or down-regulated by OJPI. Whereas several genes involved in anti-apoptosis, cell proliferation and growth, and cell cycle regulation were down-regulated, expression levels of several genes involved in apoptosis, tumor suppression, and other signal transduction events were up-regulated. These results suggest that OJPI inhibits the growth of HT-29 human colon cancer cells by various apoptosis-aiding activities as well as apoptosis itself. Therefore, OJPI deserve further development as an effective agent exhibiting anticancer activity.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.6
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• pp.551-557
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• 2013

In intelligent robot research, hand gesture recognition has been an important issue. And techniques that recognize simple gestures are commercialized in smart phone, smart TV for swiping screen or volume control. For gesture recognition, robust hand detection is important and necessary but it is challenging because hand shape is complex and hard to be detected in cluttered background, variant illumination. In this paper, we propose efficient hand detection algorithm for detecting pointing hand for recognition of place where user pointed. To minimize false detections, ROIs are generated within the compact search region using skin color detection result. The ROIs are verified by HOG-SVM and pointing direction is computed by both detection results of head-shoulder and hand. In experiment, it is shown that proposed method shows good performance for hand detection.

• The Journal of the Korea Contents Association
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• v.13 no.7
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• pp.141-149
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• 2013

Recently, the time in which children moves by car become frequent, they stay longer in the car because leisure life including camping and etc. increased. Children whose physical activities are active were subject to restriction because of the limited car boarding visual space and on security. Because of limited space in cars, domestic and foreign automotive companies show the different glass roof applied in cars that exhibited wide clear view in order to remove tedious and stuffy of children while they stay for a long time inside the car. In addition, the potential probability in which the Smart Car that the IT technology is grafted research and research that it utilizes the door window glass as the display is progressed and which the glass roof can be used as the screen can be sufficient. In this study, the in-vehicle display application case and Smart Devices constellation application were benchmarked. The car glass roof application method of the constellation studying content which performed the user survey for the child by the car with the parents whose movement is frequent and considers the child and fundamental interaction way tried to be drawn and we try to propose.

• The Journal of the Convergence on Culture Technology
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• v.2 no.2
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• pp.17-22
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• 2016

As the change in the analog age to the digital age with the development of civilization, people are living in a more friendly smart phone screen more books. In the past, people can easily see the text in the book, and now letters are disappearing from people's minds. And although they can see the letters easily anytime, anywhere using smart devices, they have no interest in the letters, they are interested only in information. So, the letters will disappear. However, there are people who try to keep the development of disappearing letters. In this paper, we are planning to produce a documentary about those people. We show that the letters survive in a modern society through Letterpress print shop, calligraphy, a computer font. And it seeks to inform that the letters are valuable.

• Journal of Digital Contents Society
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• v.12 no.3
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• pp.263-270
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• 2011

The importance of effective delivery of information in the mobile web is increasing in Korea, due to the growing number of smart-phone users. In this study, I took a look at the characteristics of mobile devices and the mobile web, and after researching Korea's portal websites' mobile web designs, we figured out the users' preferences of mobile web designs through surveys and interviews. To provide compressed information on a small screen, it is ideal for significant contents to show up in the state that does not require scrolling. Users preferred compact and neat designs, and menus that were made with icons that are easy to touch with fingers, in the mobile web. When receiving delivered information, users preferred not only texts but texts that were provided together with photograph images. If usability evaluations and examination of preferences are achieved together, I think it will serve as a mobile web guideline that enables efficient delivery of information in the mobile web.

• Science of Emotion and Sensibility
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• v.17 no.3
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• pp.3-14
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• 2014

Since the domestic introduction of iPhone in 2009, use of smartphones rapidly increased and many tasks, previously performed by various devices, are now performed by smartphones. In this process the importance of reading little text using small smartphone screen has become highly significant. This research tested how display factors of smartphone (pixel density, sub-pixel structure, luminance) and environmental factor (illumination) affect legibility related discomfort in text reading. The results indicated that legibility related discomfort is largely affected by pixel density, where people experience inconvenience when the pixel density becomes lower than 300 PPI. Illumination has limited effect on legibility related discomfort. Participants reported more legibility related discomfort when stimulus presented in various levels of illumination rather than single illumination level. Sub-pixel structure and luminance did not affected legibility related discomfort. Based on the results we suggest lower limit resolution of smart devices (smartphones, tablet computers) of different sizes for text legibility.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.8
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• pp.1053-1059
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• 2021

In order to realize a smart home, a new type of service that converges the two technologies is required as a method to overcome the respective limitations of augmented reality and IoT technologies. Augmented reality recognizes objects and projects augmented content with the recognized objects on the screen. This technology mainly uses image processing methods such as markers as a method for recognizing objects. In this paper, an augmented reality-based IoT control platform using markers was developed. By defining a marker unique to the object, a unique identifier displayed on the camera was distinguished. A smart home system was implemented by calling a controller to control things. The proposed system receives state information of objects through symptom reality and transmits control commands. The proposed platform was verified by manipulating household lights.

• Journal of the Korea Convergence Society
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• v.13 no.2
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• pp.235-248
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• 2022

Through the research on the design evaluation index of parent-child interactive game furniture, it is convenient for designers to quantitatively analyze the design advantages and disadvantages of related products, which is of positive help to control and improve the design quality. Combined with AHP and TOPSIS, this study proposes the evaluation model of three design criteria and 26 design indexes. After expert scoring, calculation, and consistency test of each index, the weight value of each design index is obtained, and the index is classified according to the importance of each index. Finally, eight essential indicators, eleven secondary indicators, and seven general indicators are classified. A case study was conducted with TOPSIS, and the design samples of three parent-child climbing game furniture were analyzed. Finally, the three samples' relative proximity was 0.505, 0281, and 0.640, respectively. The research shows that the AHP-TOPSIS method can scientifically and effectively sort and screen the advantages and disadvantages of design schemes and provide a reference for the research and development of related products.