• 제목/요약/키워드: Branching Structure

검색결과 101건 처리시간 0.029초

용융중합에 의한 분지형 폴리카보네이트의 유변학적 특성 연구 (A Study on the Rheological Properties of Branched Polycarbonates by Melt Polymerization)

  • 최수정;윤경화;김희승;유승윤;김연철
    • 폴리머
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    • 제35권4호
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    • pp.356-362
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    • 2011
  • 폴리카보네이트(polycarbonate, PC)에 화학적 구조가 다른 두 가지의 분지제를 첨가하여 용융중합으로 분지형 폴리카보네이트(branched PC, B-PC)를 합성하였다. 분지제의 함량은 0.001~0.005 mol% 내에서 조절하였다. 합성된 PC의 화학구조는 FTIR, $^1H$ NMR파 $^{13}C$ NMR 스펙트럼을 이용하여 확인하였으며, 분자량, 유리전이온도 및 분해온도는 GPC, DSC와 TGA를 이용하여 측정하였다. Phloro type의 분지제를 가지는 B-PC의 분자량에 낮은 값을 보여주었으며, 유리전이온도는 분자량에 따라 증가하였다. 두 형태의 B-PC 모두 선형 PC와 비교하였을 때 낮은 주파수(frequency) 영역에서 복합점도(complex viscosity)가 높게 나타났고, shear thinning 현상이 크게 나타났다. Shear thinning의 정도를 표시하는 power law index(n)는 선형회귀분석에 의해 계산되었고 0.483~0.996 범위의 값을 보여주었다. Phloro 타입의 B-PC가 높은 shear thinning 경향을 보였으며 이들 B-PC의 유변학적 특성은 동적유변측정기를 이용하여 측정하였다.

인터랙티브 영화는 21세기의 새로운 서사극이 될 수 있는가? : <블랙미러: 밴더스내치>를 중심으로 (Can interactive cinema become a new epic theater in the 21st century? : Focusing on )

  • 김지연;김도균;권호창
    • 트랜스-
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    • 제12권
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    • pp.245-274
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    • 2022
  • 인터랙티브 영화는 영화와 관객 간의 상호작용성을 기반으로 한 영화로, 관객의 선택에 따라 장면의 순서와 내용이 바뀔 수 있다는 특징을 갖는다. 인터랙티브 영화에 대한 논의를 크게 두 상반되는 관점으로 양분해 볼 수 있다. 하나는 새로운 영화 형식으로서 인터랙티브 영화가 가진 가능성을 긍정적으로 바라보며 다양한 방식으로 이를 '실험'하고자 하는 관점이고, 다른 하나는 인터랙티브 영화의 상호작용성이 관객에게 자유와 능동성에 대한 환상을 심어주면서 편향성을 강화할 위험이 있다는 비판적 '경고'의 관점이다. 우리는 이 두 관점을 모두 고려하면서 인터랙티브 영화의 특성 분석을 통해 그것이 가진 정치적·미학적 가능성을 현실화할 수 있는 방향을 모색하고자 한다. 이를 위해 이론적·실천적 참조틀로서 브레히트의 서사극 이론을 이론적 기반으로 삼아, 대중적·비평적 주목을 받은 바 있는 인터랙티브 영화 <블랙미러: 밴더스내치>를 분석하였다. 이 작품의 텍스트/컨텍스트적 특성을 상호작용적 다중 분기 구조, 자기반영적 미장아빔 구조, 관객의 능동적 향유 세 차원에서 분석하고, 이를 서사극 이론과 비교하였다. 이를 통해 21세기 새로운 기술/미디어 환경에서 새로운 서사극으로서의 인터랙티브 영화의 조건과 가능성을 확인하였다.

An efficient search of binary tree for huffman decoding based on numeric interpretation of codewords

  • Kim, Byeong-Il;Chang, Tae-Gyu;Jeong, Jong-Hoon
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 ITC-CSCC -1
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    • pp.133-136
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    • 2002
  • This paper presents a new method of Huffman decoding which gives a significant improvement of processing efficiency based on the reconstruction of an efficient one-dimensional array data structure incorporating the numeric interpretation of the accrued codewords in the binary tree. In the Proposed search method, the branching address is directly obtained by the arithematic operation with the incoming digit value eliminating the compare instruction needed in the binary tree search. The proposed search method gives 30% of improved Processing efficiency and the memory space of the reconstructed Huffman table is reduced to one third compared to the ordinary ‘compare and jump’ based binary tree. The experimental result with the six MPEG-2 AAC test files also shows about 198% of performance improvement compared to those of the widely used conventional sequential search method.

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Single Image-Based 3D Tree and Growth Models Reconstruction

  • Kim, Jaehwan;Jeong, Il-Kwon
    • ETRI Journal
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    • 제36권3호
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    • pp.450-459
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    • 2014
  • In this paper, we present a new, easy-to-generate system that is capable of creating virtual 3D tree models and simulating a variety of growth processes of a tree from a single, real tree image. We not only construct various tree models with the same trunk through our proposed digital image matting method and skeleton-based abstraction of branches, but we also animate the visual growth of the constructed 3D tree model through usage of the branch age information combined with a scaling factor. To control the simulation of a tree growth process, we consider tree-growing attributes, such as branching orders, branch width, tree size, and branch self-bending effect, at the same time. Other invisible branches and leaves are automatically attached to the tree by employing parametric branch libraries under the conventional procedural assumption of structure having a local self-similarity. Simulations with a real image confirm that our system makes it possible to achieve realistic tree models and growth processes with ease.

A New Sponge, Antho (Acarnia) seogwipoensis (Poecilosclerida: Microcionidae) from Korea

  • Kim, Hyung June;Sim, Chung Ja
    • Animal Systematics, Evolution and Diversity
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    • 제31권3호
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    • pp.141-145
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    • 2015
  • A new marine sponge, Antho (Acarnia) seogwipoensis n. sp., of the family Microcionidae, was collected from Seogwipo-si, Jeju-do, Korea, about 100 m in depth using a gill net on 1969. The genus Antho Gray, 1867 including Demospongiae, Poecilosclerida, Microcionidae, is a large group of sponges. About 100 species in Antho were reported from worldwide. The genus Antho contains five subgenera: Antho, Acarnia, Isopenectya, Jia, and Plocamia. Among them, about 30 species in Acarnia were described in world sponge. A new sponge's body shape is branching, size up to 124 mm wide, 213 mm high, 3-8 mm thick in branch and 7-9 mm thick in stalk. Antho (Acarnia) seogwipoensis n. sp. is similar to A. (A.) novizelanicum Ridley and Duncan, 1881 based on their spicules type and skeletal structure, but differs in the spicules dimension and growth form. This new species is branched growth form and have three kinds of toxa.

Excited-State Dynamics of Carotenoids Studied by Femtosecond Transient Absorption Spectroscopy

  • Lee, Ingu;Lee, Sebok;Pang, Yoonsoo
    • Bulletin of the Korean Chemical Society
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    • 제35권3호
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    • pp.851-857
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    • 2014
  • Carotenoids, natural antenna pigments in photosynthesis share a symmetric backbone of conjugated polyenes. Contrary to the symmetric and almost planar geometries of carotenoids, excited state structure and dynamics of carotenoids are exceedingly complex. In this paper, recent infrared and visible transient absorption measurements and excitation dependent dynamics of 8'-apo-${\beta}$-caroten-8'-al and 7',7'-dicyano-7'-apo-${\beta}$-carotene will be reviewed. The recent visible transient absorption measurements of 8'-apo-${\beta}$-caroten-8'-al in polar and nonpolar solvents will also be introduced to emphasize the complex excited-state dynamics and unsolved problems in the $S_2$ and $S_1$ excited states.

Morphometrics of Scinaia latifrons (Nemaliales, Rhodophyta) in the Southwestern Gulf of California, Mexico

  • Leon-Cisneros, Karla;Riosmena-Rodriguez, Rafael
    • ALGAE
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    • 제20권1호
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    • pp.31-36
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    • 2005
  • Scinaia latifrons Howe occurs in rhodolith beds between 9 to 27 m depths at San Lorenzo channel, Gulf of California, Mexico. As very little was known about the morphometrics of this normally temperate species in a subtropical area, we investigated the phenological changes from December 1998 to December 1999. The gametophytic phase of the species was present from late February to late May, which represented a shorter time period to other known species in the genus. Our results suggested that two gametophytic cohorts develop over winter and early spring based on the size class structure of the frond height. Thalli became reproductively mature at a small size (1-2 cm in height) and all the plants were monoecious. Scinaia latifrons at the study location underwent allometric growth, indicated by the lack of correlation between size, width of the plants, or branching patterns.

최적의 모드 결합을 얻기 위해 수정된 결합 영역을 갖는 전기광학 폴리머 디지탈 광스위치의 해석 (Analysis of electro-optic polymer digital optical switch with a coupling region modified for optimum mode coupling)

  • 이상신;신상영
    • 전자공학회논문지D
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    • 제34D권4호
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    • pp.87-93
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    • 1997
  • An electro-optic polymer digital optical switch with a coupling region modified for optimum mode coupling is proposed, and it is analyzed by using the beam propagation method combined with the effective index method. Its modified coupling region is adiabatically introduced along the propagation direction from the branching point of the two waveguides. The structure of the modified coupling region and its refractive index profiles are designed to optimize the mode coupling in the Y-branch waveguide. Therefor, the switching performance of the device may be enhanced with a fixed device length. It is confirmed from the numerical calculation that the drive voltage is reduced by more than 30 percents and te crosstalk is improved by about 8dB.

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한국산 홍조식물 보라색 우무속(Symphyocladia)직물의 분류 (Taxonomy of the Genus Symphyocladia (Rhodophyta))

  • Lee, In-Kyu
    • Journal of Plant Biology
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    • 제38권3호
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    • pp.297-303
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    • 1995
  • Four species of Symphyocladia growing along the coast of Korea were investigated in taxonomic point of view. Characters available for identification of the species were; difference in gross morphology, degree of cortication in vegetative axis, presence or absence of vegetative trichoblasts, and developmental pattern of stichidia. Vegetative structure and reproductive organs in developmental anatomy were similar among species. Branching pattern and occurrence of vegetative trichoblasts adopted for systematic criteria between Pterosiphonieae and Polysiphonieae, and between Symphyocladia and Pterosiphonia were no more confidential. The degree of congenital fusion of laterals with the parent axes was considered as only main character to distinguish Symphyocladia from Pterosiphonia.

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Measurement of Branching Ratio for broad 27-keV Resonance of $^{19}F(n,g)^{20}F$ Reaction by using Time-of-flight Method with Anti-Compton NaI(Tl) Spectrometer

  • Lee, Sam-Yol
    • 한국방사선학회논문지
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    • 제2권1호
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    • pp.31-34
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    • 2008
  • The neutron capture spectrum for the light nuclide was very useful to study the nuclear structure. In the present study, the capture gamma-ray from the 27-keV resonance of $^{19}F(n,g)^{20}F$ reaction were measured with an anti-Compton NaI(Tl) spectrometer and the 3-MV Pelletron accelerator of the Research Laboratory for Nuclear Reactors at the Tokyo institute of technology. A neutron Time-of-Flight method was adopted with a 1.5 ns pulsed neutron source by the $^7Li(p,n)^7Be$ reaction. In the present experiment, a Teflon(($CF_2$)n) sample was used The sample was disk with a diameter of 90mm. The thickness of sample was determined so that reasonable counting rates could be obtained and the correction was not so large for the self-shielding and multiple scattering of neutrons in the sample, and was 5mm. The primary gamma-ray transitions were compared with previous measurement of Kenny.

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