• Advances in nano research
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• 제12권5호
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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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• 제25권2호
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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.

• 복식문화연구
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• 제31권3호
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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.

• 복식문화연구
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• 제31권6호
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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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• 제40권4호
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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.

• 인삼문화
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• 제4권
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• pp.38-58
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• 2022

박완서의 소설은 여성문제, 자본주의 체제, 노년 문제 등을 현실감 있게 다룸으로써 문학계는 물론 여성학, 사회학 등 많은 분야에서 사회 현상의 분석 도구로 활용된다. 박완서 소설의 특징은 본인이 체험했던 사실들을 소설의 배경으로 배치한다. 하지만 소설 「미망」은 예외적으로 그가 경험하지 못한 일들을 전해 내려오는 이야기와 취재를 바탕으로 줄거리를 구성했다. 이는 잊지 못하는(未忘) 고향 개성 이야기를 통해서 시대정신을 보여 주려 한 것이다. 「미망」은 인삼재배와 상업을 기반으로 거대 자본가로 성장한 전처만과 그의 가족을 중심으로 한 4대에 걸친 가족 연대기가 줄거리를 이룬다. 19세기 후반부터 한국전쟁이 끝나는 시기까지를 배경으로 소설은 역사적 격동기에 살아왔던 인물의 행적을 중심으로 인삼과 개성상인이 상징하는 시대적 의미를 풀어낸다. 개성은 고려인삼의 메카로서 인삼과 개성상인 이야기를 빼고는 개성의 전형을 그릴 수 없다. 실재했던 사실들을 토대로 픽션이 가미된 「미망」은 근대사의 사료적 가치, 개성의 풍속사 뿐만아니라 미시사로서 인삼 역사의 소중한 증언이 담겨있다. 「미망」에는 개성의 시대상과 인삼 상인의 정신, 식민지 시절 일본의 인삼 약탈과 삼업인의 저항, 인삼 자본의 근대 자본주의로 전환 등의 흔적이 화석처럼 박혀있다. 특히 의미가 깊은 것은 소설 속 이야기들이 역사적 사실과 조응해 인삼사의 한 장(章)을 구성한다는 것이다. 「미망」에서 나타난 인삼의 상징성은 크게 세 가지로 볼 수 있다. 첫째, 고려인삼의 정기를 보여 준다. 인삼 농사의 정성과 까다로움, 삼업(蔘業) 정신과 자부심을 통해 인삼의 영물(靈物)스러움을 드러낸다. 둘째, 일본의 인삼 수탈을 민족수난사로 상징한다. 이를 지키려는 인삼 상인들의 노력과 독립운동 지원을 중요한 테마로 풀어내 민족정신을 나타낸다. 셋째, 지주, 상업 자본에 머물지 않고 생산 자본으로 전환, 근대기업화하고 사회에 기여하는 개성 인삼 상인의 근대 자본가적 진취성을 보여 준다. 세 개의 상징성은 그 당시 인삼 상인이 추구하던 시대정신을 보여 주는 것으로 우리 민족과 인삼의 관계를 더욱 명징하게 드러낸다.

• 한국항해항만학회지
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• 제29권10호
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• pp.853-858
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• 2005

최근의 해안, 해양공학 분야에서는 구조물이 있는 영역의 파동을 계산하기 위해 Navier-Stokes 방정식을 기초로 한 많은 기법들이 개발되고 발전되어 왔다. 이들 중 파랑의 쇄파현상 등의 복잡한 파동현상을 재현하기 위한 수치해석 기법으로 Volume Of Fluid method (보프법)에 근거를 둔 수치해석 기법이 자주 사용되어지고 있다. 그러나 보프법은 일반적으로 방대한 계산시간과 기억용량이 요구되는 단점을 가지고 있어, 적어도 100주기 이상의 계산시간을 통한 해석이어야만 만족할 만한 결과가 나타나는 불규칙파랑의 경우, 보프법의 단독 적용으로는 현실적으로 어려워진다. 한편, 경계요소법(BEM)의 경우는 파랑을 신속하고, 정확하게 계산할 수 있으나, 비선형 현상을 재현할 수 없는 단점이 있다. 본 연구는 불규칙 파랑을 대상으로 하고, 구조물이 있는 경우의 파동현상도 계산이 가능한 수치 해석 기법의 개발을 목표로 하고 있다. 이를 위해, 두 기법의 장점을 살려 쇄파현상 등으로 인해 비선형 현상의 재현이 요구되는 영역에서는 보프법을 사용하여 계산하고, 비선형성을 무시할 수 있어 포텐셜이론이 적용 가능한 구간에서는 BEM을 사용하여 계산을 하도록 두 기법을 연결한 BEM-VOF model을 개발하였다. 개발된 수치모델의 검증은 5차 스톡스파의 파랑전파 및 불규칙파랑의 전파를 통해 수행하였다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2005년도 추계학술대회 논문집
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• pp.153-159
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• 2005

최근의 해안, 해양공학의 수치해석 기술은 구조물이 있는 영역에서의 파동을 계산하기 위해 Navier-Stokes방정식을 기초로 한 많은 수법들이 개발되고 발전되어 왔다. 이들 중, 파랑의 쇄파현상등의 복잡한 파동현상을 재현할 목적의 수치해석 기법으로 Volume Of Fluid method (보프법)에 근거를 둔 수치해석 기법이 자주 사용되어지고 있다. 그러나 보프법은 일반적으로 방대한 계산시간과 기억용량이 필요로 하다는 단점을 가지고 있어, 보프법의 단독 수법으로는 적어도 100주기 이상의 계산시간을 통한 해석이어야만 만족할 만한 결과가 나타나는 불규칙파랑에 대한 해석이 현실적으로 어렵다는 단점이 있다. 한편, 완전유체로 가정할 경우, 경계요소법(BEM)으로 파랑을 신속하고, 정확하게 개산할 수 있으나, 비선형 현상을 재현할 수 없는 단점이 있다. 본 연구는 불규칙파랑을 대상으로 하고, 구조물이 있는 경우의 파동현상도 계산이 가능한 수치 해석 기법의 개발을 목표로 하고 있다. 이를 위해, 두 수법의 장점을 살려 쇄파현상등이 있어 비선형 현상의 재현이 요구되는 영역에서는 보프법을 사용하여 계산하고, 비선형성을 무시할 수 있어 포텐샬 이론이 적용 가능한 구간에서는 BEM을 사용하여 계산을 하도록 두 수법을 연결한 BEM-VOF model을 개발하였다. 개발된 수치모델의 검증으로는 5차 스톡스파의 파랑전파 및 불규칙파랑의 전파를 통해 수행하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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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.

• 한국가구학회지
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• 제19권1호
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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.