• Title/Summary/Keyword: Lens model

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Numerical Analyses of 2011 East Japan Tsunami Propagation towards Korean Peninsula (2011년 동일본 지진해일의 한반도 전파 수치해석)

  • Bae, Jae-Seok;Cho, Young-Joon;Kwon, Seok-Jae;Yoon, Sung-Bum
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.24 no.1
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    • pp.66-76
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    • 2012
  • The effect of bathymetry near the south sea area of Korea on the propagation of 2011 East Japan Tsunami is analyzed based on the numerical simulation using the finite difference dispersion-correction model. It is found that the bathymetry from the source to Korean Peninsula, such as Nankai Trough, Ryukyu Islands and the topographical lens in the East China Sea, plays an important role to reduce the tsunami height along the south coast of Korea. The mechanism involved in the transformation of tsunamis over those topographies is discussed.

Recombinant Adeno-associated Virus-Mediated Gene Transfer in Homocystinuria Mice (호모시스틴뇨증 동물 모델의 유전자 치료)

  • Park, Eun-Sook
    • Journal of The Korean Society of Inherited Metabolic disease
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    • v.5 no.1
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    • pp.9-17
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    • 2005
  • Homocystinuria is a metabolic disorder caused by a deficiency of cystathionine ${\beta}$-synthase (CBS). Patients with homocystinuria show clinical symptoms such as mental retardation, lens dislocation, vascular disease with life-threatening thromboembolisms and skeletal deformities. Generally, the major treatments for CBS deficiency include pharmacologic doses of pyridoxine or dietary restriction of methionine. However, there is no effective treatment for this disease up till today and gene therapy can be an attractive novel approach to treatment of the disease. We investigated whether a recombinant adeno-associated virus could be used as a CBS gene transfer vector to reduce the excessive homocysteine level in the homocystinuria mouse model. Recombinant adeno-associated virus vector encoding the human CBS gene (rAAV-hCBS), driven by EF1-a promoter, was infused into CBS-deficient mice ($CBS^{-/-}$) via intramuscular (IM) and intraperitoneal (IP) injection. IP injection was more efficient than IM injection for prolongation of lives and reduction of plasma homocysteine levels. After 2 weeks of gene transfer by IP injection, serum homocysteine level was significantly decreased in treated mice compared with the age-matched controls and the life span was extended about 1.5 times. Also, increased expression of CBS gene was observed by immunohistochemical staining in livers of treated $CBS^{-/-}$ mice and microvesicular lipid droplets was decreased in cytoplasm of liver. These results demonstrate the possibility and efficacy of gene therapy by AAV gene transfer in homocystinuria mice.

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Comparing the application of social network service with existing method on the efficiency and velocity of spreading mobilization order -Based on the circumstance of Ulchi focus lens training of South Korean military- (기존의 예비군 동원 방식과 소셜네트워크를 응용한 새로운 동원 체계의 효율 및 확산 속도 비교연구 -을지 포커스 렌즈 훈련 상황 전제-)

  • Sung, Ki-Seok;Kang, Sung-Woo
    • Journal of the Korea Safety Management & Science
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    • v.14 no.3
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    • pp.183-191
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    • 2012
  • Since June 25th 1950, the beginning of the cold war (Korean war), Korean peninsula is still in a state of war. Officially South and North Korean government call a truceafter three years from the beginning day, however both countries are still having several combats in these days. So every Korean citizen male has duty for serving military duty and this lasts even after the serving regular military force, as reserved military. Although South Korea is very small country, the size of military is very large so informing all reserved military takes some time. Since this nation is confronting the enemy and considering the global potential threat, South Korean military needs expedite informing system to call up the reserved military to active duty. In this project, the current informing system has been analyzed and compared with the new method which is using social network service such as Twitter. However mobilization order is very critical. So in our new model there are two ways combined. Using twitter to inform and then use traditional ways to finish the order. This method will provide more efficient and accurate way to cover the call ups.

Determinants of Software-as-a-Service Adoption Intention Among Small and Medium-sized Korean Firms (중소기업의 Software-as-a-Service 도입의도 결정요인 연구)

  • Kim, Sung-Hyun;Jang, Si-Young
    • Korean Management Science Review
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    • v.30 no.2
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    • pp.11-30
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    • 2013
  • Small and medium-sized enterprises (SMEs) constitute an important part of current industrial economies. Information technologies can be useful strategic weapons for SMEs by enhancing their competitiveness. Categorized as one kind of cloud computing, SaaS is a computing resource and software sharing model which can be accessed via the Internet. Based on virtualization technology, SaaS is expected to improve the efficiency and quality of the IT service level in SMEs. This study attempts to identify the determinants of SaaS adoption intention among Korean SMEs. Through the lens of the theory of planned behavior, this study adopts technological, organizational, environmental factors to explore the determinants of cloud computing adoption intention. The research population is the SMEs that have been funded by the Korean government. Partial least square method was used for empirical analysis of 190 samples collected through on-line survey. The results show that the positive attitude is influenced by business process improvements. Vender support and top management support are positively associated with subjective norm. Vendor support, top management support can relieve perceived behavior control factors. Government support directly influences adoption intention of cloud computing. These findings can provide useful strategy for both SMEs and vendors of SaaS.

Parametric Video Compression Based on Panoramic Image Modeling (파노라믹 영상 모델에 근거한 파라메트릭 비디오 압축)

  • Sim Dong-Gyu
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.43 no.4 s.310
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    • pp.96-107
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    • 2006
  • In this paper, a low bitrate video coding method based on new panoramic modeling is proposed for panning cameras. An input video frame from a panning camera is decomposed into a background image, rectangular moving object regions, and a residual image. In coding the background, we employ a panoramic model that can account for several image formation processes, such as perspective projection, lens distortion, vignetting and illumination effects. Moving objects aredetected, and their minimum bounding rectangular regions are coded with a JPEG-2000 coder. We have evaluated the effectiveness of the proposed algorithm with several indoor and outdoor sequences and found that the PSNR is improved by $1.3{\sim}4.4dB$ compared to that of JPEG-2000.

Non-axisymmetric Features of Dwarf Elliptical Galaxies

  • Kwak, Sungwon;Kim, Woong-Tae;Rey, Soo-Chang;Kim, Suk
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.1
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    • pp.39.3-39.3
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    • 2016
  • About one tenth of dwarf elliptical galaxies found in the Virgo cluster have a disk component, and some of them even possess substructures such as bars, lens, and spiral arms. We use N-body simulations to study the formation of these non-axisymmetric features in disky dwarf elliptical galaxies. By mimicking VCC 856, a bulgeless dwarf galaxy with embedded faint spiral arms, we construct 11 sets of initial conditions with slight dynamical variations based on observational data. Our standard model starts slowly to form a bar at ~3 Gyr and then undergoes buckling instability that temporarily weakens the bar although the bar strength continues to grow afterward. We find 9 of our models are unstable to bar formation and undergo buckling instability. This suggests that disky dwarf elliptical galaxies are intrinsically unstable to form bars, accounting for a population of barred dwarf galaxies in the outskirts of the Virgo cluster. To understand the origin of the faint grand-design spiral arms, we additionally construct 6 sets of models that undergo tidal interactions with their neighbors. We find that faint spiral arms consistent with observations develop when tidal forcing is relatively weak although strong encounter still results in bar formation. We discuss our results in light of the dynamical evolution of dwarf elliptical galaxies including mergers.

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Implementation of Optical Pattern Recognition System Based on Perceptron Neural Network (Perceptron 신경회로망에 근거한 광 패턴인식 시스템의 구현)

  • 한종욱;용상순;이진호;이기서;김은수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.16 no.6
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    • pp.545-555
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    • 1991
  • In this paper, We discuss optical implementation of new optical adaptive patern recognition system based on single layer perception with learning capability and associative memory model having error corrective capability. The single layer perceptron is optically implemented by using 2 D LCTV spatial light modulators through the nonlinear quantization and polarization encoding methods, and 2 D hopfield associative memory is also implemented by using multifocus holographic lens. From some experimental results on classfication of Arabic numbers into even & edd numbers, it is shown that the proposed system can classify the patterns to the right classes correctly even for the partial and erronenous input patterns. Accordingly, the proposed optical adaptive pattern recognition system can be suggested for practical application in the fields of image processing and pattern recognition.

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Analysis of British SCONUL's Information Literacy Standards (영국 SCONUL의 정보리터러시 기준 분석)

  • Choi, Jae-Hwang
    • Journal of the Korean Society for Library and Information Science
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    • v.49 no.2
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    • pp.5-26
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    • 2015
  • The aims of this study are to review the changes and trends of information literacy standards in higher education in the U.S. and the U.K.; to examine British SCONUL's two information literacy standards which were announced in 1999 and in 2011 respectively; and to compare and analyze the two information literacy standards (i.e., Core Model and Research Lens) which were released by SCONUL in 2011. By employing the research methods of literature review and content analysis, this study tries to find the implications that may be used as a basic data when the country's relevant institutions plan to consider the information literacy standards in higher education in the near future.

Frequency-Based Image Analysis of Random Patterns: an Alternative Way to Classical Stereocorrelation

  • Molimard, J.;Boyer, G.;Zahouani, H.
    • Journal of the Korean Society for Nondestructive Testing
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    • v.30 no.3
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    • pp.181-193
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    • 2010
  • The paper presents an alternative way to classical stereocorrelation. First, 2D image processing of random patterns is described. Sub-pixel displacements are determined using phase analysis. Then distortion evaluation is presented. The distortion is identified without any assumption on the lens model because of the use of a grid technique approach. Last, shape measurement and shape variation is caught by fringe projection. Analysis is based on two pin-hole assumptions for the video-projector and the camera. Then, fringe projection is coupled to in-plane displacement to give rise to 3D measurement set-up. Metrological characterization shows a resolution comparable to classical (stereo) correlation technique ($1/100^{th}$ pixel). Spatial resolution seems to be an advantage of the method, because of the use of temporal phase stepping (shape measurement, 1 pixel) and windowed Fourier transform (in plane displacements measurement, 9 pixels). Two examples are given. First one is the study of skin properties; second one is a study on leather fabric. In both cases, results are convincing, and have been exploited to give mechanical interpretation.

Design and Lithographic Fabrication of Elliptical Zone Plate Array with High Fill Factor

  • Anh, Nguyen Nu Hoang;Rhee, Hyug-Gyo;Ghim, Young-Sik
    • Current Optics and Photonics
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    • v.5 no.1
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    • pp.8-15
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    • 2021
  • An elliptical zone plate (EZP) array is important in off-axis optical systems because it provides two advantages. First, the residual beam and the main source are not focused in the same direction and second, the light from the observation plane is not reflected back towards the beam source. However, the fill factor of the previous EZP array was about 76% which was a little low. Hence, this EZP array could not collect the maximum amount of illumination light, which affected the overall optical performance of the lens array. In this study, we propose a new EZP array design with a 97.5% fill factor used in off-axis imaging system for enhancement of brightness and contrast. Then, direct laser lithography was used to fabricate the high fill factor EZP array by moving the XY linear stage of the system in a zigzag motion. The imaging properties of the proposed EZP array were experimentally verified at the focal plane and compared with the previous model.