• Title/Summary/Keyword: Spatial Properties

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Stochastic Response Analysis of Transmission Tower Subjected to Young's Modulus Variation (송전철탑의 탄성계수의 변이에 따른 확률적 응답변이도)

  • 동원영;정영수
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1993.10a
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    • pp.207-215
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    • 1993
  • With the aid of finite element method, this paper deals with the problem of structural response variability of transmission tower subjected to the spatial variability of material properties, Young's modulus herein. The spatial variability of material property are modeled as two-dimensional stochastic field which has an isotropic auto-correlation function. Response variability has been computed based on two numerical techniques, such as the Neumann expansion method in conjunction with the Monte Carlo simulation method. The results by these numerical methods are compared with those by the deterministic approach.

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Analysis of information encoding in a chaotic neural network (카오스 신경회로망에서의 정보의 인코딩 해석)

  • 여진경
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 2002.06a
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    • pp.367-371
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    • 2002
  • I construct a chaotically driven contraction system having some analogy with the information transfer mechanism in the brain system especially from CA1 cell to CA3 cell known from the empirical result. And I consider the properties of the response system on a state space according to the external input into the drive neuron by observing the fractal hierarchical structure. Then I induce the relation between the information about state transition of the chaotic time series and the spatial information on a fractal attractor to confirm the possibility of encoding of time series data to spatial information.

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Tip Enhanced Nano Raman Scattering in Graphene

  • Mun, Seok Jeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.87.2-87.2
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    • 2016
  • As an era of nano science approaches, the understanding on the shape and optical properties of various materials in a nanoscale range is getting important more seriously than ever. Accordingly the development of high spatial-temporal-spectral resolution measurement tools for characterization of nanomaterials/structures is highly required. Generally, the various properties of sample can be measured independently, e.g. to observe the structural property of sample, we use the scanning electron microscopy or atomic force microscopy, and to observe optical property, we have to use another independent measurement tool such as photoluminescence spectroscopy or Raman spectroscopy. In the case of nano-materials, however, it is very difficult to find out the same position of sample at every different measurement processes, and the condition of sample can be changed by the influence of first measurement. The tip enhanced Raman scattering(TERS), which can simultaneously measure the two or more information of sample with nanoscale spatial resolution, is one of solutions of this problem. In this talk, I will present our recent nano Raman scattering data of graphene that measured by TERS and optimized tip fabrication method for efficient experiment.

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The physical properties and switching characteristics of amorphous As-Ge-Te thin film (비정질 As-Ge-Te 박막의 물리적 성질 및 스위칭 특성)

  • 이현용;천석표;이영종;정홍배
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.44 no.7
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    • pp.901-907
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    • 1995
  • The switching characteristics of As$_{10}$ Ge$_{15}$ Te$_{75}$ thin film were investigated under d.c. bias. And the frequency dependence of the conductivity was analysed with regard to the temperature dependence, in order to find the physical properties of the As$_{10}$ Ge$_{15}$ Te$_{75}$ thin film ; a characteristic relaxation time (.tau.$_{0}$ ), the spatial density of defect states (N), and the localized wavefunction (.alpha.$^{-1}$ ). It was formed that the threshold voltage depends on thickness, electrode distance, annealing time and temperature, respectively. The threshold voltage is increased as the thickness and the electrode distance is increased, while the threshold voltage is decreased in proportion to the increased annealing time and temperature.

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A Study on the Modal Parameters of the scaled building structure (축소 건물모델의 모달 파라미터 추정에 관한 연구)

  • Park, Hae-Dong;Park, Jin-Il;Choi, Hyun;Kim, Doo-Hoon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.571-575
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    • 2000
  • The physical properties of the spatial model, mass, stiffness and damping matrix, can be defined by a specific natural frequency, damping ratio and mode shape. These modal parameters can be determined from a set of frequency response function(FRF) measured by exciting the structure and measuring the responses at various points around the structure. In this paper, The Transfer Matrix is obtained by experimental modal analysis for the 3-story scaled building model which TMD is installed on top and the physical properties of the spatial model is determined using the residue matrix and the location of poles from FRF measurement using polynomial curve fitting methods.

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Development of a distributed rainfall-runoff model with TIN-based topographic representation and its application to an analysis of spatial variability of soil properties on runoff response

  • Tachikawa, Yasuto;Shiiba, Michiharu
    • Journal of Korea Water Resources Association
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    • v.33 no.S1
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    • pp.28-36
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    • 2000
  • A TIN, Triagulated Irregular Network, based topographic modeling method and a distributed rainfall-runoff model using the topographic representation is presented. In the TIN based topographic representation, a watershed basin is modeled as a set of contiguous non-overlapping triagular facets : the watershed basin is subdivided according to streamlines to deal with water movement one-dimensionally ; and each partitioned catchment is approximated to a slope element having a quasi-three-dimensional shape by using cubic spline functions. On an approximated slope element, water movement is represented by combined surface-subsurface kinematic wave equations considering a change of slope gradient and slope width. By using the distributed rainfall-runoff model, the effects of spatial variability of soil properties on runoff response are examined.

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Impact Localization of a Composite Plate Using a Single Transducer and Spatial Focusing Signal Processing Techniques (단일 센서와 공간집속 신호처리 기술을 이용한 복합재 판에서의 충격위치 결정)

  • Cho, Sungjong;Jeong, Hyunjo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2012.10a
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    • pp.715-722
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    • 2012
  • A structural health monitoring (SHM) technique for locating impact position in a composite plate is presented in this paper. The technique employs a single sensor and spatial focusing properties of time reversal (TR) and inverse filtering (IF). We first examine the focusing effect of back-propagated signal at the impact position and its surroundings through simulation. Impact experiments are then carried out and the localization images are found using the TR and IF signal processing, respectively. Both techniques provide accurate impact location results. Compared to existing techniques for locating impact or acoustic emission source, the proposed methods have the benefits of using a single sensor and not requiring knowledge of material properties and geometry of structures. Furthermore, it does not depend on a particular mode of dispersive Lamb waves that is frequently used in the SHM of plate-like structures.

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SAFETY EVALUATION OF ROCK-FILL DAM

  • HoWoongShon;YoungChulOh;YoungKyuLee
    • Journal of the Korean Geophysical Society
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    • v.6 no.2
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    • pp.89-97
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    • 2003
  • For safety evaluation of a rockfill dam, it is often necessary to investigate spatial distribution and dynamic characterization of weak zones such as fractures. For this purpose, both seismic and electric methods are adopted together in this research. The former employs the multichannel analysis of surface waves (MASW) method, and aims at the mapping of 2-D shear-wave velocity (Vs) profile along the dam axis that can be associated with dynamic properties of filled materials. The latter is carried out by DC- resistivity survey with a main purpose of mapping of spatial variations of physical properties of dam materials. Results from both methods are compared in their signature of anomalous zones. In addition, downhole seismic survey was carried out at three points within the seismic survey lines and results by downhole seismic survey are compared with the MASW results. We conclude that the MASW is an efficient method for dynamic characterization of dam-filling materials, and also that joint analyses of these two seemingly unrelated methods can lead to an effective safety evaluation of rock-fill dam.

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SOME ASPECTS OF ZARISKI TOPOLOGY FOR MULTIPLICATION MODULES AND THEIR ATTACHED FRAMES AND QUANTALES

  • Castro, Jaime;Rios, Jose;Tapia, Gustavo
    • Journal of the Korean Mathematical Society
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    • v.56 no.5
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    • pp.1285-1307
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    • 2019
  • For a multiplication R-module M we consider the Zariski topology in the set Spec (M) of prime submodules of M. We investigate the relationship between the algebraic properties of the submodules of M and the topological properties of some subspaces of Spec (M). We also consider some topological aspects of certain frames. We prove that if R is a commutative ring and M is a multiplication R-module, then the lattice Semp (M/N) of semiprime submodules of M/N is a spatial frame for every submodule N of M. When M is a quasi projective module, we obtain that the interval ${\uparrow}(N)^{Semp}(M)=\{P{\in}Semp(M){\mid}N{\subseteq}P\}$ and the lattice Semp (M/N) are isomorphic as frames. Finally, we obtain results about quantales and the classical Krull dimension of M.

Sub-grid study of scaling effects to evapotranspiration of heterogeneous forest landscape at the Volga source area in Russia

  • Oltchev, A.;G.Gravenhorst;A.P.Tishenko;Joo, Y.T.
    • Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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    • 2001.06a
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    • pp.151-152
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    • 2001
  • A common problem of the model simulations of the land surface - atmosphere interaction is to choose the appropriate spatial scale and resolution at which the simulations are to be performed. The accuracy of energy and water exchange predictions between the land surface and the atmosphere in regional and global scale atmospheric models is mainly influenced by: model simplifications applied to describe the spatial heterogeneity of land surface properties within individual grid cells; ignoring the variability of sub-grid properties (e.g. relief, vegetation, soils), and; lacks of necessary input meteorological and biophysical data.(omitted)

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