• 제목/요약/키워드: star-shaped.

검색결과 84건 처리시간 0.026초

Displacement Properties of Nano Structure Dendrimer

  • Song Jin-Won;Lee Kyung-Sup;Lee Woo-Ki;Choi Young-Il;Yoon Suk-Am;Choi Chung-Seog
    • KIEE International Transactions on Electrophysics and Applications
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    • 제5C권1호
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    • pp.28-32
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    • 2005
  • In the Langmuir-Blodgett (LB) technique, a monolayer on the water surface is transferred onto a substrate, which is raised and dipped through the surface. From this, multilayers can be obtained in which constituent molecules are periodically arranged. The LB technique has attracted considerable interest in the fabrication of electrical and electronic devices. Many researchers have investigated the electrical properties of monolayer and multiplayer films. Dendrimers represent a new class of synthetic macromolecules characterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends that distinguish dendrimers from conventional star-like polymers and microgels. The azobenzene dendrimer is one of the dendritic macromolecules that include the azo-group exhibiting a photochromic character. Due to the presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and ptoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current.

Chinese Holstein Cattle Shows a Genetic Contribution from Native Asian Cattle Breeds: A Study of Shared Haplotypes and Demographic History

  • Ferreri, Miro;Gao, Jian;Wang, Zhi;Chen, Liben;Su, Jingliang;Han, Bo
    • Asian-Australasian Journal of Animal Sciences
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    • 제24권8호
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    • pp.1048-1052
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    • 2011
  • The Chinese Holstein cattle breed, an introduced breed in China, has been crossbred with native cattle breeds. We hypothesised that the Chinese Holstein local population in Beijing share haplotypes with native Asian cattle breeds, the result of a sudden population expansion in the recent past. We also hypothesised that crossbreeding and population expansion left traces that shaped the genetic makeup of the breed. Evaluation of this was performed by mitochondrial DNA (mtDNA) sequence analysis of Chinese Holstein cattle from Beijing (n = 41) and a comparison of them with the published mtDNA sequences (n = 293) of 14 Asian breeds with an emphasis on Chinese native cattle breeds. Three shared common haplotypes between Chinese Holstein cattle and native Asian cattle were found. Moreover, a high level of haplotype diversity in Chinese Holstein cattle (h = 0.9557) and low nucleotide diversity (${\pi}$ = 0.0052) was found, indicating a past population bottleneck followed by rapid population growth. These findings are supported by the significantly negative deviation of Tajima's D (-1.82085), the star-like pattern of dominant haplotypes and the pairwise mismatch distribution analysis, which showed a unimodal pattern.

나노구조 덴드리머의 변위전류 특성 (Displacement Current Properties for Nano Structure Dendrimer)

  • 송진원;최용성;이우기;이경섭
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 영호남 합동 학술대회 및 춘계학술대회 논문집 센서 박막 기술교육
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    • pp.52-54
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    • 2006
  • In the Langmuir-Blodgett (LB) technique, a monolayer on the water surface is transferred onto a substrate, which is raised and dipped through the surface. From this, multi layers can be obtained in which constituent molecules are periodically arranged. The LB technique has attracted considerable interest in the fabrication of electrical and electronic devices. Many researchers have investigated the electrical properties of monolayer and multiplayer films. Dendrimers represent a new class of synthetic macromolecules characterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends that distinguish dendrimers from conventional star-like polymers and microgels. The azobenzene dendrimer is one of the dendritic macromolecules that include the azo-group exhibiting a photochromic character. Due to the presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and ptoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current.

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반도체 산업용 나노기공 함유 유기실리카 박막

  • 차국헌;윤도영;이진규;이희우
    • 한국결정학회:학술대회논문집
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    • 한국결정학회 2002년도 정기총회 및 추계학술연구발표회
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    • pp.48-48
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    • 2002
  • It is generally accepted that ultra low dielectric interlayer dielectric materials (k < 2.2) will be necessary for ULSI advanced microelectronic devices after 2003, according to the International Technology Roadmap for Semiconductors (ITRS) 2000. A continuous reduction of dielectric constant is believed to be possible only by incorporating nanopores filled with air (k = 1.0) into electrically insulating matrices such as poly(methyl silsesquioxane) (PMSSQ). The nanopo.ous low dielectric films should have excellent material properties to survive severe mechanical stress conditions imposed during the advanced semiconductor processes such as chemical mechanical planarization process and multilayer fabrication. When air is incorporated into the films for lowering k, their mechanical strength has inevitably to be sacrificed. To minimize this effect, the nanopores are controlled to exist in the film as closed cells. The micromechanical properties of the nanoporous thin films are considered more seriously than ever, particularly for ultra low dielectric applications. In this study, three approaches were made to design and develop nanoporous low dielectric films with improved micromechanical properties: 1) wall density increase of nanoporous organosilicate film by copolymerization of carbon bridged comonomers; 2) incorporation of sacrificial phases with good miscibility; 3) selective surface modification by plasma treatment. Nanoporous low-k films were prepared with copolymerized PMSSQ and star-shaped sacrificial organic molecules, both of which were synthesized to control molecular weight and functionality. The nanoporous structures of the films were observed using field emission scanning electron microscopy, cross-sectional transmission electron microscopy, atomic force microscopy, and positronium annihilation lifetime spectroscopy(PALS). Micromechanical characterization was performed using a nanoindentor to measure hardness and modulus of the films.

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체크원피스(Check dress)의 시각적 이미지에 관한 연구 (A Study on the Visual Image of Check Dress)

  • 김정미
    • 한국의상디자인학회지
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    • 제17권4호
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    • pp.91-100
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    • 2015
  • The purpose of this study is to analyze the style of check dresses shown in collections from 2011 to 2014 and to extract main expressional words for the development of semantic differential scales of visual images according to the change in silhouette of block check dresses. The results of this study are as follows: 1) 120 check dresses shown in collections were composed of 57 straight silhouette dresses, 38 fitted silhouette dresses, 23 hourglass silhouette dresses, 1 barrel silhouette dress, and 1 atypical silhouette dress. And check pattern mostly used in the current collections a square pattern of block check, tartan check that is a Scotch traditional lattice pattern, a small lattice pattern of gingham check, over check that other check patterns are arranged on check pattern, star-shaped hound tooth check, glen check mixing small pattern and big pattern. The visual image for check dress differs according to changes in the check pattern and silhouette of the dress. 2) Main expressional words of visual images for block check dresses differ greatly depending on the silhouette of dresses. The visual images are ranked in the order of 'graphic', 'simple', 'hard', 'modern' for straight silhouette of block check dresses. The words of 'lively', 'girlish', 'feminine', 'cute' are ranked for hourglass silhouette of block check dresses. And the words of 'confident', 'feminine', 'modern' are marked down for fitted silhouette of block check dresses.

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매설지선의 접지임피던스의 주파수의존성에 대한 모사기법 (A Method of Simulating the Frequency-dependent Ground Impedance of Counterpoises)

  • 이복희;신희경;성창훈
    • 조명전기설비학회논문지
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    • 제26권3호
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    • pp.73-79
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    • 2012
  • A counterpoise is commonly employed in grounding systems installing near the ground surface of low resistivity soils and radial-type counterpoises are used in the limited space. Recently some studies on the evaluation of ground impedance of paralleling ground electrodes have carried out, but the data for providing the frequency-dependent ground impedances considering potential interferences are not yet sufficient. In order to provide the information about the design of grounding systems for surge protection, the simulations of the frequency-dependent ground impedance of various shaped counterpoises are carried out by using the distributed parameter circuit model including the effect of potential interferences. This paper presents the theoretical simulations and actual experiments of the frequency-dependent ground impedance of paralleling and 3 or 4-arms star counterpoises. The accuracy of the simulation methodology is examined by the comparison with the measured results, and the results show a good agreement between the simulation and the experiment.

나노구조 단분자막의 전기적 특성 연구 (A Study of Electrical Characteristics of Nano-Structural Monolayers)

  • 송진원;신훈규;이경섭;최용성
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제55권12호
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    • pp.586-590
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    • 2006
  • Dendrimers represent a new class of synthetic macromoleculcs characterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends that distinguish dendrimers from conventional star-like polymers and microgels. The azobenzene dendrimer is one of the dendrimeric macromolecules that include the azo-group exhibiting a photochromic character. Due to the presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and photoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current. Functional photoisometrization organic molecular the photo-stimulus to organic monomolecular L films and LB films of dendrimer and 8A5H were performed. The 8A5H organic monolayer in case of pressure stimulus occurred that positive course but in case of the photo-stimulus compared positive and negative. It is assumed that generation forms of displacement current were measured when photo-stimulus for impression.

덴드리머의 전기적 특성 연구 (A Study on Electrical Properties of Dendrimer)

  • 최용성;송진원;이우기;이경섭
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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    • pp.1330-1332
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    • 2006
  • In the Langmuir-Blodgett (LB) technique, a monolayer on the water surface is transferred onto a substrate, which is raised and dipped through the surface. From this, multilayers can be obtained in which constituent molecules are periodically arranged. The LB technique has attracted considerable interest in the fabrication of electrical and electronic devices. Many researchers have investigated the electrical properties of monolayer and multiplayer films. Dendrimers represent a new class of synthetic macromolecules characterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends that distinguish dendrimers from conventional star-like polymers and microgels. The agobenzene dendrimer is one of the dendritic macromolecules that include the azo-group exhibiting a photochromic character. Due to the Presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and ptoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current.

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나노구조 덴드리머의 변위전류 특성 (Displacement Current Characteristics of Nano-Structural Dendrimer)

  • 송진원;최용성;이경섭
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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    • pp.358-359
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    • 2006
  • In the Langmuir-Blodgett (LB) technique, a monolayer on the water surface is transferred onto a substrate, which is raised and dipped through the surface. From this, multilayers can be obtained in which constituent molecules are periodically arranged. The LB technique has attracted considerable interest in the fabrication of electrical and electronic devices. Many researchers have investigated the electrical properties of monolayer and multiplayer films. Dendrimers represent a new class of synthetic macromolecules characterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends that distinguish dendrimers from conventional star-like polymers and microgels. The azobenzene dendrimer is one of the dendritic macromolecules that include the azo-group exhibiting a photochromic character. Due to the presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and ptoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current.

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SEMICLASSICAL ASYMPTOTICS OF INFINITELY MANY SOLUTIONS FOR THE INFINITE CASE OF A NONLINEAR SCHRÖDINGER EQUATION WITH CRITICAL FREQUENCY

  • Aguas-Barreno, Ariel;Cevallos-Chavez, Jordy;Mayorga-Zambrano, Juan;Medina-Espinosa, Leonardo
    • 대한수학회보
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    • 제59권1호
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    • pp.241-263
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    • 2022
  • We consider a nonlinear Schrödinger equation with critical frequency, (P𝜀) : 𝜀2∆v(x) - V(x)v(x) + |v(x)|p-1v(x) = 0, x ∈ ℝN, and v(x) → 0 as |x| → +∞, for the infinite case as described by Byeon and Wang. Critical means that 0 ≤ V ∈ C(ℝN) verifies Ƶ = {V = 0} ≠ ∅. Infinite means that Ƶ = {x0} and that, grossly speaking, the potential V decays at an exponential rate as x → x0. For the semiclassical limit, 𝜀 → 0, the infinite case has a characteristic limit problem, (Pinf) : ∆u(x)-P(x)u(x) + |u(x)|p-1u(x) = 0, x ∈ Ω, with u(x) = 0 as x ∈ Ω, where Ω ⊆ ℝN is a smooth bounded strictly star-shaped region related to the potential V. We prove the existence of an infinite number of solutions for both the original and the limit problem via a Ljusternik-Schnirelman scheme for even functionals. Fixed a topological level k we show that vk,𝜀, a solution of (P𝜀), subconverges, up to a scaling, to a corresponding solution of (Pinf ), and that vk,𝜀 exponentially decays out of Ω. Finally, uniform estimates on ∂Ω for scaled solutions of (P𝜀) are obtained.