• Title/Summary/Keyword: continuity and discontinuity

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Genetic discontinuity of Digenea (Rhodomelaceae, Rhodophyta) from Mexico supports recognition of two new species, D. mexicana and D. rafaelii

  • Boo, Ga Hun;Robledo, Daniel;Andrade-Sorcia, Gabriella;Boo, Sung Min
    • ALGAE
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    • v.33 no.3
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    • pp.231-241
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    • 2018
  • Genetic continuity of Digenea simplex outside the Atlantic waters remains less studied, despite its long exposure to oriental folk medicine and wide distribution in tropical waters. Mitochondrial COI-5P and plastid rbcL sequences and morphology were investigated for plants from Mexico and additional specimens from Japan. Two new species, Digenea mexicana and Digenea rafaelii, are described for plants that would previously have been recognized as D. simplex in Mexico. D. mexicana grows to 10.5 cm tall and has cylindrical axes, irregular or di-, trichotomous branches, simple to branched determinate branchlets with eight pericentral cells, and tetrasporangia on inflated upper parts of determinate branchlets. It occurs intertidally in Quintana Roo, Yucatan Peninsula. D. rafaelii grows to 5 cm tall and has cylindrical axes, irregular or di-, trichotomous branches, and simple determinate branchlets with ten pericentral cells. It occurs intertidally in the Gulf of California. Both COI-5P and rbcL sequences revealed the genetic discontinuity between D. mexicana and D. rafaelii.

A Study on the Spatial Characteristics in the Tugendhat House (투겐타트 주택의 공간적 특성에 관한 연구)

  • 양재혁;견진현
    • Korean Institute of Interior Design Journal
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    • no.40
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    • pp.42-51
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    • 2003
  • This study aimed at understanding the spatial characteristics in the Tugendhat house. For this study, it is need to analyze the early plans of the Tugendhat house design process. To analyze this, the study leads to how to effect on the real practice with the process. Therefore, this research investigates the conceptional design process of the house. There are 2 main characteristics of the interior space alternation. One is the closed spatial character on the 2nd floor, the other is the open spatial character on the 1st floor. It clearly shows the severance between interior and exterior on the 2nd floor. Each 2nd floor's space volume uses different materials so that each the space can show the individuality. On the 1st floor, however, it seems the interior is not as much open to the exterior, because the materiality and reflection of the glass, the objet of furniture and wall. In case of 1st floor, it has a complex concept as open and close character, because it is using the proper gardening elements and the relationship between the house and site. The exterior characteristic is separated the house from the ground with the podium and the slope, and this leads to have the discontinuity. The house clearly shows the spatial characteristics of the continuity and discontinuity, it proves that Mies tried to move onto modem architecture as a turning point.

2D evaluation of crack openings using smeared and embedded crack models

  • Gamino, Andre Luis;Manzoli, Osvaldo Luis;de Oliveira e Sousa, Jose Luiz Antunes;Bittencourt, Tulio Nogueira
    • Computers and Concrete
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    • v.7 no.6
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    • pp.483-496
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    • 2010
  • This work deals with the determination of crack openings in 2D reinforced concrete structures using the Finite Element Method with a smeared rotating crack model or an embedded crack model. In the smeared crack model, the strong discontinuity associated with the crack is spread throughout the finite element. As is well known, the continuity of the displacement field assumed for these models is incompatible with the actual discontinuity. However, this type of model has been used extensively due to the relative computational simplicity it provides by treating cracks in a continuum framework, as well as the reportedly good predictions of reinforced concrete members' structural behavior. On the other hand, by enriching the displacement field within each finite element crossed by the crack path, the embedded crack model is able to describe the effects of actual discontinuities (cracks). This paper presents a comparative study of the abilities of these 2D models in predicting the mechanical behavior of reinforced concrete structures. Structural responses are compared with experimental results from the literature, including crack patterns, crack openings and rebar stresses predicted by both models.

Texture Mapping using Multiperiodic Function on the Smooth Genus N Object (Multiperiodic 함수를 이용한 Smooth Genus N 객체의 텍스쳐매핑)

  • Hwa Jin Park
    • Journal of Korea Multimedia Society
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    • v.5 no.1
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    • pp.94-104
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    • 2002
  • This paper presents a new way of texture mapping on the Genus N object constructed over a single domain. The problem of 2D texture mapping is the discontinuity of texture domain at the virtual boundary on the object. Such phenomenon decreases smoothness of the object as well as looks unnatural. Especially it is necessary for the Genus N object of infinite coninuity to apply the seamless texture mapping. For seamless texture mapping, a multiperiodic function, which transforms a discontinuous function into a continuous function, is suggested. In some applications, however, the visual seams on the textured object provide more realistic appearance. Therefore, this research supports the interactive control from the discontinuity and the continuity across the boundary using the coefficient of the weight function.

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Free vibration analysis of cracked thin plates using generalized differential quadrature element method

  • Shahverdi, Hossein;Navardi, Mohammad M.
    • Structural Engineering and Mechanics
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    • v.62 no.3
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    • pp.345-355
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    • 2017
  • The aim of the present study is to develop an elemental approach based on the differential quadrature method for free vibration analysis of cracked thin plate structures. For this purpose, the equations of motion are established using the classical plate theory. The well-known Generalized Differential Quadrature Method (GDQM) is utilized to discretize the governing equations on each computational subdomain or element. In this method, the differential terms of a quantity field at a specific computational point should be expressed in a series form of the related quantity at all other sampling points along the domain. However, the existence of any geometric discontinuity, such as a crack, in a computational domain causes some problems in the calculation of differential terms. In order to resolve this problem, the multi-block or elemental strategy is implemented to divide such geometry into several subdomains. By constructing the appropriate continuity conditions at each interface between adjacent elements and a crack tip, the whole discretized governing equations of the structure can be established. Therefore, the free vibration analysis of a cracked thin plate will be provided via the achieved eigenvalue problem. The obtained results show a good agreement in comparison with those found by finite element method.

Parametric Study on the Pressure Continuity Residual for the Stabilization of Pressure in Incompressible Materials (비압축성 물체의 압력해 안정화를 위한 압력연속여분치의 매개변수 연구)

  • 이상호;김상효
    • Computational Structural Engineering
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    • v.8 no.4
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    • pp.189-198
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    • 1995
  • The conventional finite element formulations for incompressible materials show pressure oscillations or pressure modes in four-node quadrilateral elements of commonly used displacement and pressure interpolations. The criterion for the stability in the pressure solution is the so-called Babugka-Brezzi stability condition, and the above elements do not satisfy this condition. In this study, a pressure continuity residual based on the pressure discontinuity at element interfaces is used to study the stabilization of pressure solutions in bilinear displacement-constant pressure four-node quadrilateral elements. This pressure residual is implemented in Q1P0 element derived from the conventional incompressible elasticity. The pressure solutions can be stable with the pressure residual though they exhibit sensitivity to the stabilization parameters. Parametric study for the solution stabilization is also discussed.

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A Stereo Matching by the Iterative Relaxation Using the Consensus of Matching Possibility (정합 일치성을 이용한 반복 이완 스테레오 정합)

  • 이왕국;김용석;도경훈;하영호
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.32B no.1
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    • pp.39-49
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    • 1995
  • Stereo vision is useful to obtain three dimensional depth information from two images taken from different view points. In this paper, we reduce searching area for correspondence by using the intra-scanline constraint, and utilize the inter-scanline constraint and the property of disparity continuity among the neighboring pixels for relaxation. Nodes with 3-D stucture are located on the axes of two views, and have matching possibility of correspondent pixels of two images. A matching is accepted if a node at the intersection of the disparity axes has the greatest matching possibility. Otherwise, the matching possibility of the node is updated by relaxation with the cooperation of neighboring nodes. Further relaxation with competition of two views is applied to a matching possibility of randomly selected node. The consensus of two views increases the confidence of matching, and removes a blurring phenomenon on the discontinuity of object. This approach has been tested with various types of image such as random dot stereogram and aerial image, and the experimental results show good matching performance.

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Robust Web Server System Using Virtual Machine Against DOS Attack (가상머신을 이용한 DoS 공격에 강건한 웹 서버 시스템)

  • Park, Seung Kyu;Yang, Hawan Seok;Kim, Bae Hyun
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.9 no.1
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    • pp.1-7
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    • 2013
  • The cloud computing is technology which gives flexible and solid infrastructure to IT environment. With this technology multiple computing environment can be consolidated in to a single server so that maximize system resource utilization. Better processing power can be achieved with less system resource. IT manager can cope with increasing unnecessary cost for additional server and management cost as well. This means a enterprise is able to provide services with better quality and create new services with surplus resource. The time required for recovery from system failure will be reduced from days to minutes. Enhanced availability and continuity of enterprise business minimize the codt and the risk produced by service discontinuity. In this paper, we propose framework architecture that is strong against denial-of-service attack.

Interrupted Aortic Arch [Type A] associated with ventricular septal defect, patent ductus arteriosus and patent foramen ovale (심실중격결손증, 개방성 대동맥관 및 개방성난원공과 동반한 대동맥궁 결손증: 1례보고)

  • 김한용
    • Journal of Chest Surgery
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    • v.24 no.2
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    • pp.206-211
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    • 1991
  • Interruption of the aortic arch may be defined as discontinuity of the aortic arch in which either an aortic vessel or a patent ductus arteriosus supplies the descending aorta. This anomaly is a rare congenital malformation that usually occurs with severe associated intracardiac congenital anomalies, such as ventricular septal defect, patent foramen ovale and abnormal arrangement of the brachiocephalic arteries. Rarely, transposition of the great vessel, truncus arteriosus are coexistent. We experienced a case of the interrupted aortic arch [Type A] associated with VSD, PDA and patent foramen ovale in a 16 years old female. One stage total correction was done under profound hypothermia with total circulatory arrest. Aortic continuity was established using patent ductus arteriosus with anterior wall of main pulmonary artery, which was anastomosed obliquely to anteromedial side of the ascending aorta. Ventricular septal defect was closed using Dacron patch and patent foramen ovale was closed directly. Postoperative course was uneventful, except mild hoarseness.

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Internal Wave Computations based on a Discontinuity in Dynamic Pressure (동압 계수의 불연속성을 이용한 내면파의 수치해석)

  • 신상묵;김동훈
    • Journal of the Society of Naval Architects of Korea
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    • v.41 no.4
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    • pp.17-29
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    • 2004
  • Internal waves are computed using a ghost fluid method on an unstructured grid. Discontinuities in density and dynamic pressure are captured in one cell without smearing or oscillations along a multimaterial interface. A time-accurate incompressible Navier-Stokes/Euler solver is developed based on a three-point backward difference formula for the physical time marching. Artificial compressibility is introduced with respect to pseudotime and an implicit method is used for the pseudotime iteration. To track evolution of an interface, a level set function is coupled with the governing equations. Roe's flux difference splitting method is used to calculate numerical fluxes of the coupled equations. To get higher order accuracy, dependent variables are reconstructed based on gradients which are calculated using Gauss theorem. For each edge crossing an interface, dynamic pressure is assigned for a ghost node to enforce the continuity of total pressure along the interface. Solitary internal waves are computed and the results are compared with other computational and experimental results.