• Title/Summary/Keyword: Large rotation

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The Versatility of Cheek Rotation Flaps

  • Kim, Kyung Pil;Sim, Ho Seup;Choi, Jun Ho;Lee, Sam Yong;Lee, Do Hun;Kim, Seong Hwan;Kim, Hong Min;Hwang, Jae Ha;Kim, Kwang Seog
    • Archives of Craniofacial Surgery
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    • v.17 no.4
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    • pp.190-197
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    • 2016
  • Background: The cheek rotation flap has sufficient blood flow and large flap size and it is also flexible and easy to manipulate. It has been used for reconstruction of defects on cheek, lower eyelid, or medial and lateral canthus. For the large defects on central nose, paramedian forehead flap has been used, but patients were reluctant despite the remaining same skin tone on damaged area because of remaining scars on forehead. However, the cheek flap is cosmetically superior as it uses the adjacent large flap. Thus, the study aims to demonstrate its versatility with clinical practices. Methods: This is retrospective case study on 38 patients who removed facial masses and reconstructed by the cheek rotation flap from 2008 to 2015. It consists of defects on cheek (16), lower eyelid (12), nose (3), medial canthus (3), lateral canthus (2), and preauricle (2). Buccal mucosa was used for the reconstruction of eyelid conjunctiva, and skin graft was processed for nasal mucosa reconstruction. Results: The average defect size was $6.4cm^2$, and the average flap size was $47.3cm^2$. Every flap recovered without complications such as abnormal slant, entropion or ectropion in lower eyelid, but revision surgery required in three cases of nasal side wall reconstruction due to the occurrence of dog ear on nasolabial sulcus. Conclusion: The cheek rotation flap can be applicable instead of paramedian forehead flap for the large nasal sidewall defect reconstruction as well as former medial and lateral canthal defect reconstruction.

Rotation Invariant Face Detection Using HOG and Polar Coordinate Transform

  • Jang, Kyung-Shik
    • Journal of the Korea Society of Computer and Information
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    • v.26 no.11
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    • pp.85-92
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    • 2021
  • In this paper, a method for effectively detecting rotated face and rotation angle regardless of the rotation angle is proposed. Rotated face detection is a challenging task, due to the large variation in facial appearance. In the proposed polar coordinate transformation, the spatial information of the facial components is maintained regardless of the rotation angle, so there is no variation in facial appearance due to rotation. Accordingly, features such as HOG, which are used for frontal face detection without rotation but have rotation-sensitive characteristics, can be effectively used in detecting rotated face. Only the training data in the frontal face is needed. The HOG feature obtained from the polar coordinate transformed images is learned using SVM and rotated faces are detected. Experiments on 3600 rotated face images show a rotation angle detection rate of 97.94%. Furthermore, the positions and rotation angles of the rotated faces are accurately detected from images with a background including multiple rotated faces.

SMBH Mass Estimate Discrepancy and Its Origin of NGC 6861

  • Jang, Minsung;Owers, Matt
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.69.2-69.2
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    • 2012
  • NGC 6861 is the brightest S0 galaxy in the Telescopium group. It has unusually high central stellar velocity dispersion (~400 km/s) and clear rotation (~250 km/s). Considering the well-known M-sigma relation, this large central dispersion implies that the central supermassive black hole (SMBH) has mass comparable to the most massive black holes in the Universe. However, the mass implied by the bulge luminosity-SMBH mass relation is an order of magnitude lower than that predicted by the M-sigma relation. In order to determine the origin of this inconsistency, we obtain integral field spectroscopy using the Wide Field Spectrograph (WiFeS) on the ANU 2.3m telescope. The data are used to map the velocity and velocity dispersion fields which show that our measurements are consistent with those from the other literature. The large field of view the WiFeS observations have allows us to map the kinematics of a much greater portion of NGC 6861 and reveals that the eastern part of the galaxy has higher velocity and dispersion than the rest of halo. We discuss the origin of the unusual fast rotation and the discrepancy of two SMBH mass estimations from three plausible perspectives: 1) the interaction between subgroups of NGC 6861 and its counterpart, NGC 6868; 2) the inhibited growth of the stellar bulge by the AGN activity which leads to an underestimate the SMBH mass when using the bulge luminosity-SMBH mass relation; and 3) gas rich minor mergers that could be crucial for increasing both rotation velocity and velocity dispersion during the evolution of NGC 6861.

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High-resolution mass models of the Large Magellanic Cloud

  • Kim, Shinna;Oh, Se-Heon;For, Bi-Qing;Sheen, Yun-Kyeong
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.2
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    • pp.71.1-71.1
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    • 2021
  • We perform disk-halo decomposition of the Large Magellanic Cloud (LMC) using a novel HI velocity field extraction method, aimed at better deriving its HI kinematics and thus mass distribution in the galaxy including both baryons and dark matter. We decompose all the line-of-sight velocity profiles of the combined HI data cube of the LMC, taken from the Australia Telescope Compact Array (ATCA) and Parkes radio telescopes with an optimal number of Gaussian components. For this, we use a novel tool, the so-called BAYGAUD which performs profile decomposition based on Bayesian MCMC techniques. From this, we disentangle turbulent non-ordered HI gas motions from the decomposed gas components, and produce an HI bulk velocity field which better follows the global circular rotation of the galaxy. From a 2D tilted-ring analysis of the HI bulk velocity field, we derive the rotation curve of the LMC after correcting for its transverse, nutation and precession motions. The dynamical contributions of baryons like stars and gaseous components which are derived using the Spitzer 3.6 micron image and the HI data are then subtracted from the total kinematics of the LMC. Here, we present the bulk HI rotation curve, the mass models of stars and gaseous components, and the resulting dark matter density profile of the LMC.

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Extraordinary Optical Transmission and Enhanced Magneto-optical Faraday Effect in the Cascaded Double-fishnet Structure with Periodic Rectangular Apertures

  • Lei, Chengxin;Man, Zhongsheng;Tang, Shaolong
    • Current Optics and Photonics
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    • v.4 no.2
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    • pp.134-140
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    • 2020
  • A significant enhancement of the magneto-optical Faraday rotation and extraordinary optical transmission (EOT) in the cascaded double-fishnet (CDF) structure with periodic rectangular apertures is theoretically predicted by using the extended finite difference time domain (FDTD) method. The results demonstrate that the transmittance spectrum of the CDF structure has two EOT resonant peaks in a broad spectrum spanning visible to near-infrared wavebands, one of them coinciding with the enhanced Faraday rotation and large figure of merit (FOM) at the same wavelength. It is most important that the resonant position and intensity of the transmittance, Faraday rotation and FOM can be simply tailored by adjusting the incident wavelength, the thickness of the magnetic layer, and the offset between two metallic rectangular apertures, etc. Furthermore, the intrinsic physical mechanism of the resonance characteristics of the transmittance and Faraday rotation is thoroughly studied by investigating the electromagnetic field distributions at the location of resonance. It is shown that the transmittance resonance is mainly determined by different hybrid modes of surface plasmons (SPs) and plasmonic electromagnetically induced transparency (EIT) behavior, and the enhancement of Faraday rotation is mostly governed by the plasmonic electromagnetically induced absorption (EIA) behavior and the conversion of the transverse magnetic (TM) mode and transverse electric (TE) mode in the magnetic dielectric layer.

Folding analysis of reversal arch by the tangent stiffness method

  • Iguchi, Shin-Ichi;Goto, Shigeo;Ijima, Katsushi;Obiya, Hiroyuki
    • Structural Engineering and Mechanics
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    • v.11 no.2
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    • pp.211-219
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    • 2001
  • This paper presents the tangent stiffness method for 3-D geometrically nonlinear folding analysis of a reversal arch. Experimental tests are conducted to verify the numerical analysis. The tangent stiffness method can accurately evaluate the geometrical nonlinearity due to the element translating as a rigid body, and the method can exactly handle the large rotation of the element in space. The arch in the experiment is made from a thin flat bar, and it is found that the folding process of the arch may be captured exactly by the numerical analysis with a model consisting of only 18 elements with the same properties.

Strain localization and failure load predictions of geosynthetic reinforced soil structures

  • Alsaleh, Mustafa;Kitsabunnarat, Akadet;Helwany, Sam
    • Interaction and multiscale mechanics
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    • v.2 no.3
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    • pp.235-261
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    • 2009
  • This study illustrates the differences between the elasto-plastic cap model and Lade's model with Cosserat rotation through the analyses of two large-scale geosynthetic-reinforced soil (GRS) retaining wall tests that were brought to failure using a monotonically increasing surcharge pressure. The finite element analyses with Lade's model were able to reasonably simulate the large-scale plane strain laboratory tests. On average, the finite element analyses gave reasonably good agreement with the experimental results in terms of global performances and shear band occurrences. In contrast, the cap model was not able to simulate the development of shear banding in the tests. In both test simulations the cap model predicted failure loads that were substantially less than the measured ones.

Shell Finite Element Based on B-Spline Representation for Finite Rotations (B-Spline 곡면 모델링을 이용한 기하비선형 쉘 유한요소)

  • 노희열;조맹효
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.10a
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    • pp.429-436
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    • 2003
  • A new linkage framework between elastic shell element with finite rotation and computar-aided geometric design (CAGD) (or surface is developed in the present study. The framework of shell finite element is based on the generalized curved two-parametric coordinate system. To represent free-form surface, cubic B-spline tensor-product functions are used. Thus the present finite element can be directly linked into the geometric modeling produced by surface generation tool in CAD software. The efficiency and accuracy of the Previously developed linear elements hold for the nonlinear element with finite rotations. To handle the finite rotation behavior of shells, exponential mapping in the SO(3) group is employed to allow the large incremental step size. The integrated frameworks of shell geometric design and nonlinear computational analysis can serve as an efficient tool in shape and topological design of surfaces with large deformations.

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Optimal Design of a 6-DOF Parallel Mechanism using a Genetic Algorithm (유전 알고리즘을 이용한 6자유도 병렬기구의 최적화 설계)

  • Hwang, Youn-Kwon;Yoon, Jung-Won
    • Journal of Institute of Control, Robotics and Systems
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    • v.13 no.6
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    • pp.560-567
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    • 2007
  • The objective of this research is to optimize the designing parameters of the parallel manipulator with large orientation workspace at the boundary position of the constant orientation workspace (COW). The method uses a simple genetic algorithm(SGA) while considering three different kinematic performance indices: COW and the global conditioning index(GCI) to evaluate the mechanism's dexterity for translational motion of an end-effector, and orientation workspace of two angle of Euler angles to obtain the large rotation angle of an end-effector at the boundary position of COW. Total fifteen cases divided according to the combination of the sphere radius of COW and rotation angle of orientation workspace are studied, and to decide the best model in the total optimized cases, the fuzzy inference system is used for each case's results. An optimized model is selected as a best model, which shows better kinematic performances compared to the basis of the pre-existing model.

Euler Parameters Method for Large Deformation Analysis of Marine Slender Structures (오일러 매개변수를 이용한 해양 세장체 대변위 거동 해석)

  • Hong, Sup
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.05a
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    • pp.163-167
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    • 2003
  • A novel method for 3-dimensional dynamic analysis of marine slender structure gas been developed by using Euler parameters. The Euler parameter rotation, which is being widely used in aerospace vehicle dynamics and multi-body dynamics, has been applied to elastic structure analysis. Large deformation of flexible slender structures is described by means of Euler parameters. Euler parameter method is implemented effectively in incremental-iterative algorithm for 3D dynamic analysis. The normalization constraint of Euler parameters is efficiently satisfied by means of a sequential updating method.

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