• Advances in nano research
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• v.12 no.5
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• pp.483-488
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• 2022

The present work is an attempt to study the vibration analysis of the single-walled carbon nanotubes (SWCNTs) under the effect of the surface irregularity using Donnell's model. The surface irregularity represented by the parabolic form. According to Donnell's model and three-dimensional elasticity theory, a novel governing equations and its solution are derived and matched with the case of no irregularity effects. To understand the reaction of the nanotube to the irregularity effects in terms of natural frequency, the numerical calculations are done. The results obtained could provide a better representation of the vibration behavior of an irregular single-walled carbon nanotube, where the aspect ratio (L/d) and surface irregularity all have a significant impact on the natural frequency of vibrating SWCNTs. Furthermore, the findings of surface irregularity effects on vibration SWCNT can be utilized to forecast and prevent the phenomena of resonance of single-walled carbon nanotubes.

• Earthquakes and Structures
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• v.25 no.2
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• pp.113-123
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• 2023

A novel type of buckling restrained brace with built-up angle steel was developed. The core segment was formed by welding angle steel, and the middle section was reduced by cutting technology to solve the problem that the end of BRB was easy to buckle. The experimental program has been undertaken to study the performance of BRBs with different unbonded materials (silica gel, kraft paper) and different filler materials (ordinary concrete, full light-weight concrete). Four specimens were designed and fabricated for low cycle reciprocating load tests to simulate horizontal seismic action. The failure mode, hysteretic curves, tension-compression unbalance coefficient and other mechanical parameters were compared and analyzed. The finite element software ABAQUS was used to conduct numerical simulation, and the simulation results were compared with the experimental phenomena. The test results indicated that the hysteretic curve of each specimen was plump. Sustaining cumulative strains of each specimen was greater than the minimum value of 200 required by the code, which indicated the ductility of BRB was relatively good. The energy dissipation coefficient of the specimen with silica gel as unbonded material was about 13% higher than that with kraft paper. The experimental results were in good agreement with the simulation results.

• The Research Journal of the Costume Culture
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• v.31 no.3
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• pp.346-360
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• 2023

The pataphysics implemented by digital technology differs from the form of objects in the real world and is used throughout the cultural industry. This study aims to analyze the expression method of pataphysics as applied to modern fashion and derive its impact on the fashion industry. The research analyzes fashion images, shows, films, displays, and e-commerce, since 2016, when pataphysics began to be used in the fashion domain. Pataphysics, created by Alfred Zaire, appeared as an overlapping phenomenon that reflects physical phenomena in the virtual world. The expression method of pataphysics applied to modern fashion was divided into an augmented reality method based on immersion and interaction, a virtual platform-oriented metaverse, and a virtual model expressing a processed self. The influence of pataphysics applied to modern fashion is as follows. In the field of design, pataphysics affects the development of contemplative designs for innovation and creativity. Second, digital technology can expand the role of fashion at the intersection of art and fashion that takes a novel perspective through pataphysics. Third, e-commerce positively affects efficient production and consumption through virtual and economic models. In conclusion, this study's findings are expected to play a positive role in promoting creativity and innovation by introducing new perspectives and ideas into modern fashion through pataphysics.

• The Research Journal of the Costume Culture
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• v.31 no.6
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• pp.806-823
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• 2023

The aim of this study was to analyze the design characteristics of Chinese fashion designer Feng Chen Wang and interpret their implicit meaning from a neo-deconstruction perspective. A review of domestic and foreign literature, outlined the develop- ment of deconstruction and neo-deconstruction, with neo-deconstruction's aesthetic features termed 'traditional fusion', 'positive playfulness', 'open communication', and 'multiple inclusiveness'. These features informed an analysis of Feng Chen Wang's fashion design. Four key findings emerged. First, 'traditional fusion' combines traditional Chinese colors, items, handicrafts, and patterns with modern design to break down boundaries between past and modern, tradition and fashion. Second, 'positive playfulness' promotes creativity and fun, using bright colors, exaggerated accessories, and playing withthe composition of traditional clothes to create a positive atmosphere. Third, 'open communication' emphasizes design that combines practicality and creati- vity in response to consumer needs, incorporating the thoughts arising from individual experiences and interest in social phenomena. Fourth, 'multiple inclusiveness' breaks down boundaries of sexuality, hierarchy, and body shape, embracing various ideas of beauty and respecting uniqueness through design that are seen as available to all. Using a neo-deconstruction perspective, Feng Chen Wang provides novel product planning ideas for Chinese fashion brands and reflects the values and meaning of modern design pursued by contemporary Chinese designers.

• Journal of Astronomy and Space Sciences
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• v.40 no.4
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• pp.237-245
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• 2023

Laser communication has been considered as a novel method for earth observation satellites with generation of high data volume. It offers faster data transmission speeds compared to conventional radio frequency (RF) communication due to the short wavelength and narrow beam divergence. However, laser beams are refracted due to atmospheric turbulence between the ground and the satellite. Refracted laser beams, upon reaching the receiver, result in angle-of-arrival (AoA) fluctuation, inducing image dancing and wavefront distortion. These phenomena hinder signal acquisition and lead to signal loss in the course of laser communication. So, precise alignment between the transmitter and receiver is essential to guarantee effective and reliable laser communication, which is achieved by pointing, acquisition, and tracking (PAT) system. In this study, we simulate the effectiveness of tip/tilt compensation for more efficient laser communication in the satellite-ground downlink. By compensating for low-order terms using tip/tilt mirror, we verify the alleviation of AoA fluctuations under both weak and strong atmospheric turbulence conditions. And the performance of tip/tilt correction is analyzed in terms of the AoA fluctuation and collected power on the detector.

• Journal of Ginseng Culture
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• v.4
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• pp.38-58
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• 2022

Park Wan-seo's novels deal with realistic topics of society, such as women's issues, the capitalist system, and the problems that come with old age. Assuch, her work is used as a tool to analyze social phenomena in various fields, such as women's studies, sociology, and literature. A characteristic style of Park Wan-seo's novels is that she bases them on her own experiences. However, among her novels, the novel Mimang is exceptional. The plot is based on stories that have been passed down from generation to generation. This is to show the spirit of the times through the unforgettable story of her hometown, Gaesong. Mimang is the story of a family chronology that spans four generations centered on Chun Cheu-Man and his family, who became powerful capitalists through the cultivation and commerce of ginseng cultivation. Set in the late 19th century until the end of the Korean War, the novel unravels the essence of the times symbolized by merchants of ginseng and Gaeseong, focusing on the actions of people living in a period of historical turbulence. Gaeseong is the mecca of Korean ginseng, and Gaeseong cannot be portrayed without the story of ginseng and its merchants. Therefore, Mimang, a fictionalized story based on real facts, contains valuable testimony of the history of ginseng, not only as historical values of modern history and personal customs but also as microhistory. In the novel, traces of the times of Gaeseong and the spirit of ginseng merchants, as shown in the Japanese sacking of ginseng during the colonial period, the resistance of ginseng merchants, and the conversion of ginseng capitalism to modern capitalism, are imprinted like fossils. What is especially meaningful is that the stories in the novel correspond to historical facts and constitute a chapter in the history of ginseng. The symbolism of ginseng in the novel can be explained in three main ways. First, it shows the essence of Korean ginseng. It reveals the soul of ginseng through the sincerity and rigor of ginseng farming, as well as the spirit and pride of ginseng. Second, it symbolizes the exploitation of ginseng in Japan as a national issue. The efforts of ginseng merchants to protect this and support the independence movement are presented as important themes to express nationalism. Third, it shows the modern capitalist progressiveness of Gaeseong ginseng merchants, who do not stay in landownership and commercial capital, but convert them to productive capital and contribute to society by modernizing them. The three symbolisms show the spirit of the times of the Gaeseong ginseng merchants, clearly revealing the meaningful relationship between the Korean people and ginseng.

• Journal of Navigation and Port Research
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• v.29 no.10 s.106
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• pp.853-858
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• 2005

Recently, various novel numerical models based on Navier-Stokes equation have been developed for calculating wave motions in the sea with coastal or ocean structures. Among those models, Volume Of Fluid (VOF) method might be the most popular one, and it has been used for numerical simulations of wave motions including complicated phenomena of wave breakings. VOF method, however, needs enormous computation time and large computational storage memories in general, thus it is practically difficult to use this method for calculations in the case of random waves because long and stable computation (e.g for more than 100 significant wave periods) is required to obtain statistically meaningful results. On the other hand if the wave motion is potential motion, Boundary Element Method (BEM), which is a much faster and more accurate method than VOF method, can be effectively used. The aim of this study is to develop a new efficient model applicable to calculations of wave motion and/or wave-structure interactions under random waves. To achieve this, a strictly combined BEM-VOF model has been developed by making the best use of both methods' merits; VOF method is used in a restricted fluid domain around a structure where complicated phenomena of wave breakings may exist, and BEM is used in the other domains far from the disturbance where the wave motion may be assumed to be potential. The verification of the model was performed with numerical results for Stokes' 5th order wave propagation and a random wave propagation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2005.10a
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• pp.153-159
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• 2005

Recently, various novel numerical models based on Navier-Stokes equation rave been developed for calculating wave motions in the sea with coastal or ocean structures. Among those models, Volume Of Fluid (VOF) method might be the most popular one, and it has been used for numerical simulations of wave motions including complicated phenomena of wave breakings. VOF method, however, needs enormous computation time and large computational storage memories in general, thus it is practically difficult to use VOF method for calculations in the case of random waves because long and stable computation ( e.g. for more than 100 significant wave periods) is required to obtain statistically meaningful results. On the other hand of the wave motion is potential motion, Boundary Element Method (BEM), which is a much faster and more accurate method than VOF method, am be effectively used. The aim of this study is to develop a new efficient model applicable to calculations of wave motion and/or wave-structure interactions under random waves. To achieve this, a strictly combined BEM-VOF model has been developed by making the best use of both methods' merits; VOF method is used in a restricted fluid domain around a structure where complicated phenomena of wave breakings may exist, and BEM is used in the other domains far from the disturbance where the wave motion may be assumed to be potential. The verification of the model was performed with numerical results for Stokes'5th order wave propagation and a random wave propagation.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.102-102
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• 2016

Water, which is most abundant in Earth surface and very closely related to all forms of living organisms, has a simple molecular structure but exhibits very unique physical and chemical properties. Even though tremendous effort has been paid to understand this nature's core substance, there amazingly still lefts much room for scientist to explore its novel behaviors. Especially, as the scale goes down to nano-regime, water shows extraordinary properties that are not observable in bulk state. One of such interesting features is the formation of nanoscale bubbles showing unusual long-term stability. Nanobubbles can be spontaneously formed in water on hydrophobic surface or by decompression of gas-saturated liquid. In addition, the nanobubbles can be generated during electrochemical reaction at normal hydrogen electrode (NHE), which possibly distorts the standard reduction potential at NHE as the surface nanobubble screens the reaction with electrolyte solution. However, the real-time evolution of these nanobubbles has been hardly studied owing to the lack of proper imaging tools in liquid phase at nanoscale. Here we demonstrate, for the first time, that the behaviors of nanobubbles can be visualized by in situ transmission electron microscope (TEM), utilizing graphene as liquid cell membrane. The results indicate that there is a critical radius that determines the long-term stability of nanobubbles. In addition, we find two different pathways of nanobubble growth: i) Ostwald ripening of large and small nanobubbles and ii) coalescence of similar-sized nanobubbles. We also observe that the nucleation and growth of nanoparticles and the self-assembly of biomolecules are catalyzed at the nanobubble interface. Our finding is expected to provide a deeper insight to understand unusual chemical, biological and environmental phenomena where nanoscale gas-state is involved.

• Journal of the Korea Furniture Society
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• v.19 no.1
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• pp.44-54
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• 2008

The blur phenomenon, in which the boundaries of fields or roles become vague, has become an important concept of design in the 21st century. In furniture design, the physical boundary between furniture and space and that between space and furniture has been broken down and their meaning tends to be redundant. This concept was begun by a variety of furniture designers who led the trends about 30 years ago. A progressive exhibition titled ${\ulcorner}$Living Tomorrow${\lrcorner}$, which was included in the Koln International Mobelmess from 1968 to 1970, showed that the blur phenomenon in furniture design has never actually been novel. These exhibitions and the works exhibited in the events are still recognized as progressive examples that proposed an avant-garde concept of life. They are in line with the current furniture design based on spatial concepts, which has been created by the blur phenomenon. The purposes of this study are to determine the cases of furniture design that enable the so-called spatial functions beyond the simple functions of seating, use, and display, from those of furniture design and to research their characteristics. In this study, furniture based on spatial concepts means furniture that creates 3D spaces consisting of the floor, walls, and ceiling by the blur phenomenon that occurs from the spaces among these pieces of furniture. The organization of this study is as follows; In Chapter 2, a background on the generation of furniture design based on spatial concepts is described based on the research literature of this socio-cultural phenomena. In Chapter 3, the cases of relevant furniture design redescribed. In Chapter 4, the collected cases are analyzed and their characteristics described. In Chapter 5, Chapter 1 to Chapter 4 are summarized and conclusions are given. In addition, future research is proposed.