• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.2
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• pp.45-53
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• 2023

The growth of Si on 4H-SiC substrate has a wide range of applications as a very useful material in power semiconductors, bipolar junction transistors and optoelectronics. However, it is considerably difficult to grow very fine crystalline Si on 4H-SiC owing to the lattice mismatch of approximately 20 % between Si and 4H-SiC. In this paper, we report the growth of a Si epilayer by an Al-related nanostructure cluster grown on a 4H-SiC substrate using a mixed-source hydride vapor phase epitaxy (HVPE) method. In order to grow hexagonal Si on the 4H-SIC substrate, we observed the process in which an Al-related nanostructure cluster was first formed and an epitaxial layer was formed by absorbing Si atoms. From the FE-SEM and Raman spectrum results of the Al-related nanostructure cluster and the hexagonal Si epitaxial layer, it was considered that the hexagonal Si epitaxial layer had different characteristics from the general cubic Si structure.

• 재활복지
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• v.15 no.4
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• pp.351-375
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• 2011

The purpose of this study is to research the actual condition of on-line and off-line computer education in order to create more opportunities for the possibility of effective learning and u-Learning - based IT vocational education development of persons with hearing impairments. To carry out this study, we had a preliminary education of this study for a sign language interpreters who had working in a association of the deaf in Daegu, and had conducted a survey study participating for 100 persons with hearing impairments living in Daegu-Kyungbook Region. The results of this study were as follows: First, during on-line and offline education environment for persons with hearing impairments, factors such as teaching methods and contents, screen organization, learning effects, offering lecture material and subtitle, subtitle and sign language video of position and size, offering computer instructor who have a sign language interpreter with IT mentoring, on-line educational user environment setting must be considered factors for u-Learning - based IT vocational education development. Second, 74% of the subjects showed their interest in taking a course, after u-Learning contents are developed for persons with hearing impairments. Third, the subjects preferred IT device was a tablet PCs and IT certification related courses as their IT vocational education curriculum. Also, to link between professional training and job opportunity, subjects will need a IT vocational education courses such as computer intermediate and advanced levels.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.4
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• pp.9-14
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• 2022

Silica aerogel is a porous material with a very low density and high specific surface area. Still, its application is limited due to its weak mechanical properties due to structural features. To solve this problem, a method of complexing it with various polymers has been proposed. We synthesized polyimide cross-linked silica aerogel by the sol-gel process to obtain high mechanical properties. Tetraethyl orthosilicate (TEOS) was used as a precursor to make silica aerogel, and 3- aminopropyltriethoxysilane (APTES) was used as a coupling agent for cross-linking polyimide. Polyimide was synthesized using pyromellitic dianhydride and 3,5-diaminobenzoic acid, and mechanical properties were improved by crosslinking polyimide with 10 repeating units in the polyimide chain using the reaction formula ${\frac{n_1}{n_2}}={\frac{n}{n+1}}$ To realize silica aerogel, polyimide having various weight ratios was added before gelation, resulting in a 19-fold or greater increase in maximum compressive strength compared to pure silica aerogel. From this study, an enhancement of silica aerogel could be enhanced through polymer cross-linking bonds.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.4
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• pp.15-20
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• 2022

Aerogel is a material having a nanopore structure based on a high porosity. Due to this high porosity, it has excellent properties not found in conventional materials, but its application has been limited due to low mechanical strength. Therefore, to improve the mechanical strength of the aerogel, polyurea crosslinking was introduced and a precursor having an amine group essential for polyurea polymer formation was selected to synthesize a polyurea crosslinked aerogel composite. In addition, the crosslinking of polyurea was adjusted according to the number of amine groups present in aminosilane. It was confirmed through various analyses that the nanopore structure of the aerogel was maintained to have mesopores. The aerogel thus formed was able to improve the mechanical strength by about two times, and it was confirmed through field emission scanning electron microscope analysis that a one-dimensional polymer was formed on the silica aerogel surface through the introduction of ethylene diamine. The one-dimensional polymer thus formed has improved mechanical properties, resulting in securing an elastic modulus of about 2.66 MPa.

• Korean Journal of Remote Sensing
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• v.39 no.5_2
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• pp.743-754
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• 2023

The global occurrence of myriad natural disasters and incidents, catalyzed by climate change and extreme meteorological conditions, has engendered substantial human and material losses. International organizations such as the International Charter have established an enduring collaborative framework for real-time coordination to provide high-resolution satellite imagery and geospatial information. These resources are instrumental in the management of large-scale disaster scenarios and the expeditious execution of recovery operations. At the national level, the operational deployment of advanced National Earth Observation Satellites, controlled by National Geographic Information Institute, has not only catalyzed the advancement of geospatial data but has also contributed to the provisioning of damage analysis data for significant domestic and international disaster events. This special edition of the National Disaster Management Research Institute delineates the contemporary landscape of major disaster incidents in the year 2023 and elucidates the strategic blueprint of the government's national disaster safety system reform. Additionally, it encapsulates the most recent research accomplishments in the domains of artificial satellite systems, information and communication technology, and spatial information utilization, which are paramount in the institution's disaster situation management and analysis efforts. Furthermore, the publication encompasses the most recent research findings relevant to data collection, processing, and analysis pertaining to disaster cause and damage extent. These findings are especially pertinent to the institute's on-site investigation initiatives and are informed by cutting-edge technologies, including drone-based mapping and LiDAR observation, as evidenced by a case study involving the 2023 landslide damage resulting from concentrated heavy rainfall.

• Phonetics and Speech Sciences
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• v.15 no.3
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• pp.27-35
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• 2023

This study aimed to investigate the effect of Chinese on the production of Korean rhythm. Korean and Chinese are typologically classified into different rhythmic categories; because of this, the phonological properties of Korean and Chinese are similar and different at the same time. As a result, Chinese can exert both positive and negative influences on the realization of Korean rhythm. To investigate the influence of the rhythm of the native language of L2 learners on their target language, we conducted an acoustic analysis using acoustic metrics like of the speech of 5 Korean native speakers and 10 advanced Chinese Korean learners. The analyzed material is a short paragraph of five sentences containing a variety of syllable structures. The results showed that KS and CS rhythms are similar in %V, VarcoV, and nPVI_S. However, CS, unlike KS, showed characteristics closer to those of a stress-timed language in the values of %V and VarcoV. There was also a significant difference in nPVI_V values. These results demonstrate a negative influence of the native language in the realization of Korean rhythm. This can be attributed to the fact that all vowels in Chinese sentence are not pronounced with the same emphasis due to neutral tone. In this sense, this study allowed us to observe influences of L1 on L2 production of rhythm.

• Journal of Advanced Navigation Technology
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• v.28 no.4
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• pp.559-565
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• 2024

Research on autonomous vehicles is being actively conducted. As autonomous vehicles emerge, there will be a transitional period in which traditional and autonomous vehicles coexist, potentially leading to a higher accident rate. Currently, when a traffic accident occurs, the fault ratio is determined according to the criteria set by the General Insurance Association of Korea. However, the time required to investigate the type of accident is substantial. Additionally, there is an increasing trend in fault ratio disputes, with requests for reconsideration even after the fault ratio has been determined. To reduce these temporal and material costs, we propose a deep learning model that automatically determines fault ratios. In this study, we aimed to determine fault ratios based on accident video through a image classification model based on ResNet-18 and video action recognition using TSN. If this model commercialized, could significantly reduce the time required to measure fault ratios. Moreover, it provides an objective metric for fault ratios that can be offered to the parties involved, potentially alleviating fault ratio disputes.

• International Journal of Advanced Culture Technology
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• v.12 no.3
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• pp.21-28
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• 2024

The public can access movies more easily than any other cultural genre. The film's costumes convey the social, political, and cultural climate of that time period. Additionally, it subtly conveys the message of the movie, including the intentions of the director and the characters. Filmmakers can now use fact-based materials to plan their films, and audiences can now watch costume in movies with objective standards, particularly in period dramas, thanks to the advancements in over-the-top (OTT) services. The 77th British Academy costume Award went to the movie Napoleon because of how much emphasis it placed on the outfit. Ninety-five percent of the costume was made by experts in military uniforms and costumery. In contrast to the previous aristocratic and exaggerated Rococo costume, Napoleonic clothing had a natural and common-class character. A natural-shaped Chemise dress composed of light, reflective material first appeared in the Directoire era, just after the French Revolution. Chemise dresses made of a variety of materials gained popularity during the Empire era. With Napoleon taking the throne and Josephine becoming the empress, the vibrant court culture resurfaced during the Empire era. The silk was embellished with gold thread and embroidery, train dangling forms, and different types of sleeves appeared in Empire styles. They wore Pellisse and shawls under the coat. The hair style had long, ancient hair and was adorned with fillets. They also wore straw hats, bonnets, and caps. Long gloves and parasols were also popular accessories, as were pearl or colored jewelry necklaces, earrings, bracelets, and rings. During the Empire era, tiaras were fashionable. Shoes were either low-heeled pumps or sandals. The movie uses Chemise and Empire costumes, which are versatile enough to be used in a range of settings and eras. When it came to details, the type of sleeve was employed without regard to time, such as when using those from an earlier or later period. Since jewelry was worn more often than not in that era, practically every character has earrings on their necklaces. Nearly exact replicas of the coronation costume can be found in paintings by Jacques-Louis David. The red trains, Josephine's Empire dress, the crown, the Tiara, and the costumes of every character in attendance were all clearly identifiable in terms of form and color. To further aid viewers in understanding and enhancing the film's overall coherence, a scene featuring David drawing the coronation was added. Overall, there were differences in that the historical costumes were accurately recreated, the materials and details were utilized without restriction, and some of the costumes were designed with modern materials or accessories that were used more than the historical costumes. This section appears to have been written to highlight the beauty of the characters' personalities or settings. There is a limitation to this study in that it only looked at aristocratic clothing, which includes Josephine's. We will concentrate on male clothing in future research.

• International Journal of Advanced Culture Technology
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• v.12 no.3
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• pp.29-36
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• 2024

The public can now access movies faster and more easily thanks to over-the-top (OTT) services. The audience may be impacted by period dramas, where accurate costume reproduction is crucial. For filmmakers, it is critical to replicate period costumes using precise historical information. The goal of this study is to act as a reference so that, when it comes to period dramas, viewers can evaluate them using impartial criteria and movie producers can use data based on fact to plan their costumes. The film Napoleon won the British Academy Award for Costume after hiring costume experts to create 95% of the entire costume, according to data from the Napoleon I Museum. Following the French Revolution, the ostentatious and ornate men's attire vanished, to be replaced by a more modest and functional outfit. For tops, vests were cut to waist length, shirts, cravats, and carrick were worn, and tailcoats were the norm. The pants were swapped out for loose-fitting ones. The glitzy hues and embellishments from the bygone era progressively vanished and formed the foundation of the contemporary men's costume, which is dominated by black. The hats worn were tricorn, bicorn, top hat, and bowler, and the hairstyle changed from long to short gradually. The civil class wore short tops called carmagnoles. Napoleon wore a high-collared Napoleon collar and a tailcoat with a bicorn, which became his emblem. Green, navy, and white were the colors of the uniform, and a gray woolen coat was worn outside. The elaborately decorated costumes were worn to court and to banquets; the Napoleonic coronation costume was embellished with gold embroidery on silk, red velvet, and martyred hair; the post-revolutionary costumes gradually became more colorful. In the movie Napoleon, period clothing items were well represented, with the aristocracies wearing dark tailcoats, vests, shirts, and cravats. Based on the data from the men's costume, Napoleon's outfit in the movie was made more similarly. This study's limitation is that not every character in the movie could have their costume examined, and the material matter could not be precisely determined by examining the images displayed on the screen. Given that portraits typically feature a great deal of noble imagery, the clothing worn by common people is also associated with data limitations when it comes to movie costume design.

• Journal of the Microelectronics and Packaging Society
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• v.31 no.3
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• pp.18-23
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• 2024

Nanoimprint lithography (NIL) is widely used to form structures ranging from micro to nanoscale due to its advantage of generating high-resolution patterns at a low process cost. However, most NIL processes require the use of imprint resists and external elements such as ultraviolet light or heat, necessitating additional post-processes like etching or metal deposition to pattern the target material. Furthermore, patterning on flexible and/or non-planar films presents significant challenges. This study introduces an extreme pressure imprint lithography (EPIL) process that can form micro-/nano-scale patterns on the surface of a flexible rubber magnet composite (RMC) film at room temperature without an etching process. The EPIL technique can form ultrafine structures over large areas through the plastic deformation of various materials, including metals, polymers, and ceramics. In this study, we demonstrate the process and outcomes of creating a variety of periodic structures with diverse pattern sizes and shapes on the surface of a flexible RMC composed of strontium ferrite and chlorinated polyethylene. The EPIL process, which allows for the precise patterning on the surface of RMC materials, is expected to find broad applications in the production of advanced electromagnetic device components that require fine control and changes in magnetic orientation.