• 제목/요약/키워드: pseudo 3-D

검색결과 269건 처리시간 0.022초

Pseudo-Combline을 이용한 이중대역 협대역 대역통과 여파기 (Narrow Band-pass Filter with Dual-band Using Pseudo-Combline)

  • 윤기철;이현욱;이맹;이재영;이종철
    • 한국ITS학회 논문지
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    • 제10권6호
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    • pp.84-90
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    • 2011
  • 본 논문은 이중대역 Pseudo-combline 협대역 대역통과 여파기를 제안한다. 제안한 이중대역 대역통과 여파기의 특징은 개방형 공진 스터브를 사용하고 있으며 ITS와 X-밴드 위성 시스템에 적용이 가능하다. 이중대역 대역통과 여파기는 첫번째 운용 주파수 대역의 중심 주파수 5.8 GHz 그리고 대역폭 3.6 %에서 삽입 및 반사 손실이 각각 1.72 dB 및 15.5 dB 이다. 또한 두 번째 운용 주파수 대역의 중심 주파수 8.5 GHz 그리고 대역폭 3%에서 삽입 및 반사 손실은 각각 1.92 dB 및 16.3 dB 이다.

LES를 이용한 Pseudo-Shock Waves의 가시화 (Numerical Visualization of the Pseudo-Shock Waves using LES)

  • ;;김희동
    • 한국가시화정보학회지
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    • 제13권3호
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    • pp.29-34
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    • 2015
  • The interaction between a normal shock wave and a boundary layer along a wall surface in internal compressible flows causes a very complicated flow. This interaction region containing shock train and mixing region is called as pseudo-shock waves. Pseudo-shock waves in the divergent part of a rectangular nozzle have been investigated by using large-eddy simulation (LES). LES studies have been done for the complex flow phenomena of three-dimensional pseudo-shock waves. The LES results have been validated against experimental wall-pressure measurements. The LES results are in good agreement with experimental results. Pseudo-shock length and corner separation have been studied in three-dimensional LES model. Comparison of centerline pressure measurement and 3D visualization measurement has been discussed for the corner separation position. It has been concluded that the pseudo-shock length should be measured by using 3D visualization measurement.

Symmetry Properties of 3-dimensional D'Atri Spaces

  • Belkhelfa, Mohamed;Deszcz, Ryszard;Verstraelen, Leopold
    • Kyungpook Mathematical Journal
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    • 제46권3호
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    • pp.367-376
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    • 2006
  • We investigate semi-symmetry and pseudo-symmetry of some 3-dimensional Riemannian manifolds: the D'Atri spaces, the Thurston geometries as well as the ${\eta}$-Einstein manifolds. We prove that all these manifolds are pseudo-symmetric and that many of them are not semi-symmetric.

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Driving altitude generation method with pseudo-3D building model for unmanned aerial vehicles

  • Hyeon Joong Wi;In Sung Jang;Ahyun Lee
    • ETRI Journal
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    • 제45권2호
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    • pp.240-253
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    • 2023
  • Spatial information is geometrical information combined with the properties of an object. In city areas where unmanned aerial vehicle (UAV) usage demand is high, it is necessary to determine the appropriate driving altitude considering the height of buildings for safe driving. In this study, we propose a data-provision method that generates the driving altitude of UAVs with a pseudo-3D building model. The pseudo-3D building model is developed using high-precision spatial information provided by the National Geographic Information Institute. The proposed method generates the driving altitude of the UAV in terms of tile information, including the UAV's starting and arrival points and a straight line between the two points, and provides the data to users. To evaluate the efficacy of the proposed method, UAV driving altitude information was generated using data of 763 551 pseudo-3D buildings in Seoul. Subsequently, the generated driving altitude data of the UAV was verified in AirSim. In addition, the execution time of the proposed method and the calculated driving altitude were analyzed.

남산에서 세포성 점균의 출현과 분포 (Occurrence and Distribution of Cellular Slime Molds in Mt. Nam)

  • 강경미;홍영빈;이재봉;장남기
    • The Korean Journal of Ecology
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    • 제21권5_3호
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    • pp.687-694
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    • 1998
  • In this study, the occurrence and distribution of dictyostelid cellular slime molds was investigted from soils of typical forests in Mt. Nam and the effect of soil environmental factor on cellular slime molds was investigated. The fourteen species including two undescribed species were isolated as follows: Dictyostelium brefeldianum, Polysphondylium pallidum, P. violaceum, P. pseudo-candidum in Quercus mongolica-Sorbus alnifolia forests, D. purpureum, D. mucoroides var. stoloniferum, D. dimigraformum, D. brefeldiamum, P. pallidum, P. tenuissimum, P. violoceum, P. candidum, P. pseudo-candidum in Pinus densiflora forests, D. polycephahum, D. capitatum, d. brefeldianun, P. candidum in Robinia pseudo-acacia forests, D. purpureum, D. aureostipes var, aureostipes, D. polycephalum in Quercus acutissima forests, D. minutum, D. implicatum. in the site disturbed by human. The dominant species were P. pallidum, D. brefeldiamum, P. pseudo-candidum and D. dimigraformum were the undescribed species in Korea. Environmental factors such as soil pH, water content, organic content, total nitrogen and total phosphorus made a little effect on total species number, the number of clones.

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3차원 물체에 대한 8진 트리 구성 알고리즘에 관한 연구 (A Study on Octree Construction Algorithm for 3D Objects)

  • 최윤호;송유진;홍민석;박상희
    • 전자공학회논문지B
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    • 제29B권1호
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    • pp.1-10
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    • 1992
  • This study presents a complete octree construction algorithm for 2D depth images obtained from orthogonal face views, which can represent 3D objects exactly. In constructing quadtree, optimal quadtree construction algorithm is applied to depth images for efficient use of memory and reduction of tree construction time. In addition, pseudo-octrees are constructed by using our proposed method, which construct pseudo-octrees according to the resolution value given in each node of constructed quadtree and mapping relation between quadrants and octants. Finally, a complete octree, which represents a 3D object, is constructed by volume intersection with each constructed pseudo-octree. The representation accuracy of a complete octree constructed by our algorithm is investigated by using a 3D display method and a volume ratio method for a complete octree.

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Glyphosate와 2,4-D의 주사처리(注射處理)가 아카시아 나무의 방제(防除)에 미치는 영향(影響) (Effects of Glyphosate and 2,4-D Injection on Selective Control of Robinia pseudo-acacia)

  • 권오원;변종영;이재창
    • 한국잡초학회지
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    • 제6권2호
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    • pp.130-133
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    • 1986
  • 아카시아 나무의 방제를 위하여 제초제의 처리약량을 줄이며 다른 수목(樹木)에는 피해를 주지 않는 선택적 방제법을 강구하고자 glyphosate와 2, 4-D를 아카시아 나무에 주사처리(注射處理)하여 경엽처리방법과 비교하여 그 방제효과(防除效果)를 검토하였다. 1. Glyphosate 1000~2000 ppm 단용(單用) 또는 2, 4-D 400ppm을 가용(加用)하여 경엽처리하였을 때 모든 처리농도에서 100% 방제되었으나 약제비산으로 인하여 아카시아나무 이외의 나무에도 피해가 발생하였다. 2. Glyphosate 3050ppm 3 ml, 6 ml 주사구(注射區)에서는 100% 방제되었고 2,4-D 1000ppm 3 ml 주사구(注射區)에서는 95%, 6ml 주사구(注射區)에서 100 % 방제되었다. 3. Glyphosate 1525ppm에 2,4-D 500ppm을 가용(加用)하여 주사(注射)했을 때는 아카시아 나무는 100% 방제되었다. 따라서 glyphosate와 2,4-D를 가용(加用)하여 주사처리(注射處理)하면 glyphosate 경엽처리에 비하여 1/64 정도의 약량, glyphosate 단독처리에 비해서는 1/16 정도의 약량으로 같은 효과를 얻을 수 있었다. 4. 이상의 결과(結果)로 glyphosate를 주사처리(注射處理)하므로서 불필요한 아카시아 나무를 선택적으로 방제할 수 있었고 특히 glyphosate에 2,4-D를 가용(加用)하므로써 glyphosate의 약량을 더욱 감소시 킬 수 있을 것으로 사료된다. 따라서 주사처리(朱射處理)에 의한 방제를 위해서는 수목(樹木)의 주간직경(注幹直徑)과 수령(樹齡)에 기초하여 약량(樂量) 및 주사량(注射量)을 결정한마면 소량의 약량(藥量)으로도 효과적(效果的)으로 수목(樹木)을 방제 할 수 있으리라 기대된다.

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CHARACTERIZATIONS OF SOME POLYNOMIAL VARIANCE FUNCTIONS BY d-PSEUDO-ORTHOGONALITY

  • KOKONENDJI CELESTIN C.
    • Journal of applied mathematics & informatics
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    • 제19권1_2호
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    • pp.427-438
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    • 2005
  • From a notion of d-pseudo-orthogonality for a sequence of poly-nomials ($d\;\in\;{2,3,\cdots}$), this paper introduces three different characterizations of natural exponential families (NEF's) with polynomial variance functions of exact degree 2d-1. These results provide extended versions of the Meixner (1934), Shanbhag (1972, 1979) and Feinsilver (1986) characterization results of quadratic NEF's based on classical orthogonal polynomials. Some news sets of polynomials with (2d-1)-term recurrence relation are then pointed out and we completely illustrate the cases associated to the families of positive stable distributions.

중진지역 건축물의 묻힌온통기초에 작용하는 토압과 말 뚝변위에 대한 지진해석 (Seismic Analyses of Soil Pressure against Embedded Mat Foundation and Pile Displacements for a Building in Moderate Seismic Area)

  • 김용석
    • 한국지진공학회논문집
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    • 제21권1호
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    • pp.69-76
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    • 2017
  • Seismic analyses of a pile under a large rigid basement foundation embedded in the homogeneous soil layer were performed practically by a response displacement method assuming a sinusoidal wave form. However, it is hard to take into account the characteristics of a large mat foundation and a heterogeneous soil layer with the response displacement method. The response displacement method is relevant to the 2D problems for longitudinal structures such as tunnel, underground cave structure, etc., but might not be relevant with isolated foundations for building structures. In this study, seismic pile analysis by a pseudo 3D finite element method was carried out to compare numerical results with results of the response displacement method considering 3D characteristics of a foundation-soil system which is important for the building foundation analyses. Study results show that seismic analyses results of a response displacement method are similar to those of a pseudo 3D numerical method for stiff and dense soil layers, but they are too conservative for a soft soil layer inducing large soil pressures on the foundation wall and large pile displacements due to ignored foundation rigidity and resistance.

SVD Pseudo-inverse를 이용한 영상 재구성 (SVD Pseudo-inverse and Application to Image Reconstruction from Projections)

  • 심영석;김성필
    • 대한전자공학회논문지
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    • 제17권3호
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    • pp.20-25
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    • 1980
  • Singular value decomposition을 통한 pseudo-inverse를 단층영상 재구성에 이용하였다. 본 논문에서는 SVD pseudo-inverse를 이용한 truncated inverse filter와 Scalar Wiener filter에 대하여 검토하고 각각에 대하여 통계적 측면에서의 최적화가 연구되었다. 이러한 방법은 신호와 잡음문에 trade-off를 기함으로써 재구성 문제에 항상 뒤따르는 ill-conditioning 현상을 극복할 수 있다. 본 논문을 통하여 구성된 filter의 성능을 확인하기 위하여 컴퓨터를 이용한 simulation이 이루어졌으며 그 결과 재구성된 협상은 만족할 만 하였다.

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