• 제목/요약/키워드: Image-crystal

검색결과 388건 처리시간 0.029초

Image-Enhanced Endoscopy in Lower Gastrointestinal Diseases: Present and Future

  • Lee, Han Hee;Lee, Bo-In
    • Clinical Endoscopy
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    • 제51권6호
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    • pp.534-540
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    • 2018
  • From dye-assisted conventional chromoendoscopy to novel virtual chromoendoscopy, image-enhanced endoscopy (IEE) is continuously evolving to meet clinical needs and improve the quality of colonoscopy. Dye-assisted chromoendoscopy using indigo carmine or crystal violet, although slightly old-fashioned, is still useful to emphasize the pit patterns of the colonic mucosa and predict the histological structures of relevant lesions. Equipment-based virtual chromoendoscopy has the advantage of being relatively easy to use. There are several types of virtual chromoendoscopy that vary depending on the manufacturer and operating principle. IEE plays distinctive roles with respect to histologic characterization of colorectal polyps and prediction of the invasion depth of colorectal cancers. In addition, the newest models of IEE have the potential to increase adenoma and polyp detection rates in screening colonoscopy.

Crystal Structure of Ferrihydrite Nanoparticles Synthesized in Ferritin

  • Kim, Sung-Won;Seo, Hyang-Yim;Lee, Young-Boo;Park, Young-Seog;Kim, Kyung-Suk
    • Bulletin of the Korean Chemical Society
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    • 제29권10호
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    • pp.1969-1972
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    • 2008
  • In this study, horse spleen apoferritins were induced to form biominerals using up to 3000 Fe atoms per protein molecule. The morphology and crystallinity of the nanometer-sized biominerals formed in the ferritins were then analyzed using field emission-energy filtering-transmission electron microscopy (FE-TEM). The ferritins were found to have reconstitution yields of 60-70% in the experiments. The mean core size of the ferritins varied somewhat with protein concentrations, indicating that crystal growth in ferritins could be controlled via protein concentrations. The core mineral size increased with the amount of Fe used. Lattice fringes of the core, associated with good crystallinity, were found in all samples. The lattice fringe images of a single domain ferrihydrite mineral appeared frequently in the (011) planes (d-spacing of 0.246 nm) under [100] zone axis in all samples of this study. In addition, the lattice image occasionally revealed fringes corresponding to the (100) planes (d = 0.254 nm) from the [001] zone axis, indicating the characteristic pattern of hexagonal crystal lattice. Diffraction patterns in the minerals identified as ferrihydrite were fitted well into the space group of $P3_{1c}$.

HPGe 검출기의 PENELOPE 전산모사에 의한 특성 분석 (A Germanium Detector Structure PENEL OPE Characteristic Analysis by Computer Simulation)

  • 장은성;장보석
    • 한국방사선학회논문지
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    • 제9권2호
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    • pp.73-77
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    • 2015
  • 검출기의 자세한 구조를 알고자 CT 스캐닝을 하였으며 크리스털 형상과 사층에 관한 세부적인 구조를 전산모사 계산법을 이용해 재현하였다. 낮은 에너지의 감마선에 대한 피크 효율이 거리가 작아질수록 감소, 보다 높은 에너지(400 keV) 아상에서의 전체 효율성은 검출기 코어를 조정함으로써 불확도를 줄일 수 있었다. PENELOPE 계산법을 이용해 얻은 공간적 의존성 사이에 적절한 일치점이 달성되었음을 확인 하였다. 이는 크리스털 코어, 모서리와 크리스털 코어의 라운딩을 설명해 주는 매개변수들을 조정함으로써 달성되었다.

Effects of Dispersed Carbon nanotubes on Electro-Optic Characteristics and Orientation of Liquid Crystal in the In-Plane Switching Cell

  • Baik, I.S.;Jeon, S.Y.;Choi, J.Y.;Lee, S.H.;Lee, J.Y.;An, K.H.;Lee, Y.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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    • pp.415-418
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    • 2005
  • To understand effects of carbon nanotubes (CNTs) dispersed in nematic liquid crystal (NLC) on electro-optic characteristic and orientation of the LC, we CNT-doped homogeneously-aligned NLC cells driven by in-plane field have been fabricated. The CNTs were aligned with a LC director from the initial state to below critical ac field, whereas the CNTs disturbed the LC director field above critical ac field. We observed motional textures in the form of vertical stripes in the local area between electrodes, which were associated with a deformation of the LC director orientation. This indicates that CNTs start vibrating three dimensionally with translational motion. Further, the hysterisis studies of voltage-dependent transmittance under dc electric field show that the amount of residual dc, which is related to image sticking problem in liquid crystal displays, is greatly reduced due to ion trapping by CNTS while keeping operating voltage and response time about the same compared to the un-doped LC cell.

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방탄소재 활용을 위한 SLS 유리 결정화의 효과 (The Effect of Crystallization of SLS Glass for Bulletproof Materials)

  • 심규인;김태윤;최세영
    • 한국군사과학기술학회지
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    • 제13권1호
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    • pp.120-125
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    • 2010
  • For application of transparent bulletproof materials, the SLS(soda-lime-silicate) glass was heated by 2-step crystallization. The DTA curve for SLS glass revealed the nucleation and crystal growth temperature at about $575^{\circ}C$ and $675^{\circ}C$, respectively. The crystallized glass was heated at various conditions(temperature, time). As a result, the maximum nucleation and crystal growth rates were $3.8\times10^5/mm^3{\cdot}hr$ at $575^{\circ}C$ and 20.58nm/min at $680^{\circ}C$, respectively. The bending strength, fracture toughness and vickers hardness were 451.7MPa, $0.9388MPa{\cdot}m^{1/2}$, and $693.9H_v$ which were 201%, 31%, and 22% higher than parent glass, respectively. Surface image and transmittance of crystallized SLS glass were analyzed by optical microscopy and UV/VIS/NIR spectrophotometer. Transmittance of crystallized SLS glass at visible-range(200~800nm) was not changed.

Viewing angle controllable in-plane switching liquid crystal display using one panel

  • Kim, Jin-Ho;Lim, Young-Jin;Her, Jung-Hwa;Srivastava, Anoop Kumar;Park, Kyoung-Ho;Lee, Joun-Ho;Kim, Byeong-Koo;Lee, Seung-Hee
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.629-632
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    • 2009
  • We have proposed a novel viewing angle controllable display of in-plane switching (IPS) mode with single panel. One pixel of this device is divided to two regions, in which main pixel shows image and sub pixel for viewing angle control. In initial state, the liquid crystal of sub pixel is homogeneous aligned on substrate for wide viewing angle mode. On the other hand, after applying voltage, the liquid crystal of sub pixel tilts up for narrow viewing angle mode. The proposed device has advantage for the function for simple manufacturing process and good viewing angle control with single panel.

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FZ법에 의한 $La_{1-x}Ca_xMnO_3$(x=0.33)의 결정성장과 전자기적 물성에 대한 연구 (A Study on the Electromagnetic Properties of $La_{1-x}Ca_xMnO_3$(x=0.33) grown by Floating Zone Method)

  • 정준기;송규정;조남희;김철진
    • 한국결정학회지
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    • 제13권1호
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    • pp.41-47
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    • 2002
  • La/sub 1-x/Ca/sub x/MnO₃ 망간산화물을 할로겐 램프를 열원으로 하는 FZ법으로 결정성장시켰다. 결정성장조건은 공기 분위기 하에서 성장속도 4∼6 mm/hr, 원료봉의 회전속도 45∼50 rpm, 성장되는 결정의 회전속도는 20-25rpm이었다. 성장된 시편의 분석은 XRD, SEM, EPMA를 이용하였으며 EBSD로 결정성장 방위를 분석하였다. 전자기적 물성 측정은 4단자 탐침법으로 Quantum Design PPMS를 이용하였고 215 K에서 462%의 MR값을 얻을 수 있었다.

소성 조건 변화에 따른 수직 폴리이미드 표면에서 이용한 네마틱 액정의 틸트 제어 (Control of Tilt Angle in the Nematic Liquid Crystal on the Homeotropic Polyimide Surface as a Function of the Baking Condition)

  • 황정연;이경준;김강우;서대식
    • 한국전기전자재료학회논문지
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    • 제17권6호
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    • pp.661-667
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    • 2004
  • The control of tilt angle for nematic liquid crystal (NLC) with negative and positive dielectric anisotropy on the rubbed homeotropic polyimide (PI) using baking method by hot plate equipment was investigated. LC tilt angle decreased with increasing baking temperature and time. Especially, the low LC tilt angle of positive type NLC (Δ$\varepsilon$>0) on the rubbed homeotropic PI surface by increasing temperature and time was measured. The tilt angle of positive type NLC(Δ$\varepsilon$>0) is smaller than that of the negative type (Δ$\varepsilon$>0) on rubbed PI with increasing baking temperature and time. We consider that the tilt angle of NLC is decreased due to increasing the steric interaction between horizon component of permittivity $\varepsilon$ = of NLC and the stress of polymer side chain by high temperature. As the increase of baking temperature, we obtain that AFM (atomic force microscope) image of rubbed PI surface using Hot-plate method has formed better solid micro-groove structure than oven method.

Three-Dimensional Metal Complex Host with Alternating Arrangement of the Occupied and Vacant Channels. The Crystal Structure of Cd(NH₂CH(CH₃)CH₂NH₂)Ni(CN)₄· 0.25G (G=$CH_3C_6H_5, p-(CH_3)_2C_6H_4$)

  • 박기민;이욱;Toschitake Iwamoto
    • Bulletin of the Korean Chemical Society
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    • 제17권10호
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    • pp.919-924
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    • 1996
  • Crystal structure of two inclusion compounds Cd(pn)Ni(CN)4·0.25G (G=toluene and p-xylene, pn=1,2-diaminopropane) have been determined from single-crystal X-ray diffraction data; toluene clathrate: monoclinic P21/n, a=13.838(6), b=26.893(5), c= 7.543(5) Å, γ=90.92(3)°, Z=4, R=0.0616; p-xylene clathrate: monoclinic P21/n, a=13.895(2), b=26.900(3), c=7.613(1) Å, γ=91.06(1)°, Z=4, R=0.0486. The host structures determined for toluene- and pxylene-guest clathrates are substantially identical to the U-type structures observed for the straight chain aliphatic-guest clathrates. However, the alternating arrangement of occupied channels with the guest molecules and vacant channels appears in the host structure. The non-centrosymmetric toluene molecules are distributed about the inversion center to give an image like p-xylene molecule. The guests, toluene and p-xylene, prefer the U-type channel, favoring the interaction between the π-electrons of the aromatic ring and the pn-amino groups to hold the aromatic ring vertical to the cyanometallate meshes.

소비자의 유행색 브랜드 개성 지각과 태도 (Consumer Trend Color Perception of Brand Personality and Attitude)

  • 정상수;이유진;이원준
    • 한국콘텐츠학회논문지
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    • 제9권12호
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    • pp.647-655
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    • 2009
  • 색상은 콘텐츠의 하나로서 소비자에게 중요한 의미를 지니게 되는데 일반적으로 개인이 보유하고 있는 색상 이미지는 시간을 두고 축적된 경험이나 지식의 산물로 존재한다. 본 연구는 향후 유행할 것으로 예측되는 유행색을 중심으로 색의 이미지가 가지고 있는 개성과 의미를 파악하고 색상에 대한 태도를 분석하고자 하였다. 연구 결과에 의하면 크리스탈 사운드, 크리미 터치, 미스테리우스 빈티지, 오톰 포레스트, 카니발 등 5개의 주요한 유행색들은 비교적 독특한 고유의 개성적 이미지를 가지고 있는 것으로 나타났다. 추가적인 형용사 이미지 분석 결과, 크리스탈 사운드는 자수성가한 사업가의 이미지를 가지고 있으며, 크리미 터치는 여고생의 이미지, 미스테리우스 빈티지는 대부의 이미지, 오톰 포레스트는 일반 대중의 이미지, 카니발은 서커스 광대의 이미지를 갖고 있는 것으로 나타났다. 이중 크리미 터치는 소비자의 태도에서 가장 높은 선호도를 보이는 것으로 나타났다. 이상의 연구 결과들은 개인의 개성과 색상의 개성의 일치성을 고려함으로서 긍정적인 소비자 행동을 유발할 가능성을 보여준다. 또한 본 연구는 패션과 마케팅을 연결한 학제적인 연구로서 가치가 있으며 향후 지속적인 연구가 필요할 것으로 보인다.