• Title/Summary/Keyword: pseudo 3-D

Search Result 269, Processing Time 0.027 seconds

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

  • Yoon, Ki-Cheol;Lee, Hyun-Wook;Li, Meng;Lee, Jae-Yeong;Lee, Jong-Chul
    • The Journal of The Korea Institute of Intelligent Transport Systems
    • /
    • v.10 no.6
    • /
    • pp.84-90
    • /
    • 2011
  • In this paper, a dual-band pseudo-combline narrow bandpass filter is proposed. The proposed bandpass filter adopts the open resonant stubs and the proposed bandpass filter can be used for ITS(Intelligent Transport System) and X-band satellite systems application. The proposed bandpass filter has the insertion and return losses of 1.72 dB and 15.5 dB at the bandwidth of 3.6 % and center frequency of 5.8 GHz, respectively. Also, the second operating frequency band for insertion and return losses are 1.92 dB and 16.3 dB at the bandwidth of 3% and center frequency of 8.5 GHz, respectively.

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

  • Deng, Ruoyu;Jin, Yingzi;Kim, Heuy Dong
    • Journal of the Korean Society of Visualization
    • /
    • v.13 no.3
    • /
    • pp.29-34
    • /
    • 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
    • /
    • v.46 no.3
    • /
    • pp.367-376
    • /
    • 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.

  • PDF

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

  • Hyeon Joong Wi;In Sung Jang;Ahyun Lee
    • ETRI Journal
    • /
    • v.45 no.2
    • /
    • pp.240-253
    • /
    • 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.

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

  • 강경미;홍영빈;이재봉;장남기
    • The Korean Journal of Ecology
    • /
    • v.21 no.5_3
    • /
    • pp.687-694
    • /
    • 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.

  • PDF

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

  • 최윤호;송유진;홍민석;박상희
    • Journal of the Korean Institute of Telematics and Electronics B
    • /
    • v.29B no.1
    • /
    • pp.1-10
    • /
    • 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.

  • PDF

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

  • Kwon, O.W.;Pyon, J.Y.;Lee, J.C.
    • Korean Journal of Weed Science
    • /
    • v.6 no.2
    • /
    • pp.130-133
    • /
    • 1986
  • Glyphosate and 2,4-D were introduced into the vascular systems of Robinia pseudo-acacia L. (3-5cm diameter) with a syringe-type pressure injector in May, 1985. Robinia pseudo-acacia L. were completely controlled by 3 or 6 ml of 3050ppm glyphosate per tree and 6ml of 1000ppm 2,4-D per tree. Herbicidal efficacy was more effective by 6m1 of combined solutions of 1525ppm glyphosate and 500ppm 2,4-D per tree.

  • PDF

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

  • KOKONENDJI CELESTIN C.
    • Journal of applied mathematics & informatics
    • /
    • v.19 no.1_2
    • /
    • pp.427-438
    • /
    • 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.

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

  • Kim, Yong-Seok
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.21 no.1
    • /
    • pp.69-76
    • /
    • 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-inverse and Application to Image Reconstruction from Projections (SVD Pseudo-inverse를 이용한 영상 재구성)

  • 심영석;김성필
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.17 no.3
    • /
    • pp.20-25
    • /
    • 1980
  • A singular value decomposition (SVD) pseudo-inversion method has been applied to the image reconstruction from projections. This approach is relatively unknown and differs from conventionally used reconstructioll methods such as the Foxier convolution and iterative techniques. In this paper, two SVD pseudo-inversion methods have been discussed for the search of optimum reconstruction and restoration, one using truncated inverse filtering, the other scalar Wiener filtering. These methods partly overcome the ill-conditioned nature of restoration problems by trading off between noise and signal quality. To test the SVD pseudo-inversion method, simulations were performed from projection data obtained from a phantom using truncated inversefiltering. The results are presented together with some limitations particular to the applications of the method to the general class of 3-D image reconstruction and restoration.

  • PDF