Home About us Contact
|
Home About us Contact | ||
|
|
||
Projection Techniques (projection + techniques)
Selected AbstractsA practical 3D measurement system based on projection pattern control techniquesELECTRONICS & COMMUNICATIONS IN JAPAN, Issue 11 2009Genki Cho Abstract Most of the recent 3D image measurement methods have employed certain pattern projection techniques because of their higher reliabilities. Especially, the intensity-modulated technique can detect more stripe addresses by a single projection and therefore is very much expected for its practical use in the near future. The traditional techniques of this type, however, have encountered several serious problems where 3D measurements are difficult in sensitivity, speed and accuracy or fatally impossible for unknown objects. In order to solve these problems, we propose an automatic control technique of angle and space frequency of projection pattern. Furthermore, for security of measurement accuracy and measurement speed, projection pattern intensity control technique and optimal intensity-modulation projection technique are adopted in the proposal measurement system. By using the proposed technique the automatic 3D measurement intended for the geostationary objects and the swaying objects were realized in experimental results. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 92(11): 34,41, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10147 [source] Zero-sequence-based relaying technique for protecting power transformers and its performance assessment using unsupervised learning ANNEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 2 2006Guzmán Díaz Abstract In this paper a simple and robust new relaying technique for protecting transformers from internal winding faults is proposed. Based on the measurement of zero sequence current inside a delta winding, the technique greatly simplifies the conventional differential relaying arrangement when a delta winding is available. Despite the number of windings of the transformer and the location of the fault, only measurement of induced zero sequence current within the delta winding is needed. Since the proposed technique has been shown to be prone to generate false pick-up signals during inrush, a simple restraining criterion is proposed and analysed. Additionally, use of projection techniques based on self-organizing maps (SOM) is proposed in this paper as a valuable tool for analysing multivariable data which are generated from the huge number of possible combinations existing between switching instant and fault location. Finite element simulations and laboratory tests have been combined into SOM to validate the proposed relaying technique and the restraining criterion. Copyright © 2005 John Wiley & Sons, Ltd. [source] Ab initio calculations and analysis of chemical bonding in SrTiO3 and SrZrO3 cubic crystalsINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 10 2006R. A. Evarestov Abstract The possibility of the different first-principles methods to describe the chemical bonding in SrTiO3 and SrZrO3 cubic crystals is investigated. The local properties of the electronic structure (atomic charges, bond orders, atomic delocalization indexes, and polarization fractions) were calculated with different methods: traditional Mulliken population analysis in LCAO calculations, two projection techniques in plane-wave (PW) calculations, population analysis based on Wannier-type atomic orbitals, and chemical bonding analysis based on the localized Wannier functions for occupied (valence band) LCAO states. All the techniques considered except the traditional Mulliken analysis demonstrate that the ionicity of chemical bonding in SrZrO3 is larger than in SrTiO3, in agreement with the Zr and Ti electronegativities relation and the relative bandgaps observed. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006 [source] Characterization of pyramidal inversion boundaries in Sb2O3 -doped ZnO by using electron back-scattered diffraction (EBSD)ACTA CRYSTALLOGRAPHICA SECTION A, Issue 3 2007Chan Park The composition planes of the inversion boundary induced by the addition of Sb2O3 to ZnO ceramics were analyzed crystallographically by the application of electron back-scattered diffraction (EBSD) analysis and stereographic projection techniques. The inversion boundary was determined to consist of three discrete composition planes, , , . [source] Reconstruction of an atmospheric tracer source using the principle of maximum entropy.THE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 610 2005I: Theory Abstract Over recent years, tracing back sources of chemical species dispersed through the atmosphere has been of considerable importance, with an emphasis on increasing the precision of the source resolution. This need stems from many problems: being able to estimate the emissions of pollutants; spotting the source of radionuclides; evaluating diffuse gas fluxes; etc. We study the high-resolution retrieval on a continental scale of the source of a passive atmospheric tracer, given a set of concentration measurements. In the first of this two-part paper, we lay out and develop theoretical grounds for the reconstruction. Our approach is based on the principle of maximum entropy on the mean. It offers a general framework in which the information input prior to the inversion is used in a flexible and controlled way. The inversion is shown to be equivalent to the minimization of an optimal cost function, expressed in the dual space of observations. Examples of such cost functions are given for different priors of interest to the retrieval of an atmospheric tracer. In this respect, variational assimilation (4D-Var), as well as projection techniques, are obtained as biproducts of the method. The framework is enlarged to incorporate noisy data in the inversion scheme. Part II of this paper is devoted to the application and testing of these methods. Copyright © 2005 Royal Meteorological Society [source] Finite element and finite volume simulation and error assessment of polymer melt flow in closed channelsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 11 2006M. Vaz Jr. Abstract This work aims at evaluating the discretization errors associated to the finite volume and finite element methods of polymer melt flow in closed channels. Two strategies are discussed: (i) Richardson extrapolation and (ii) a posteriori error estimation based on projection/smoothing techniques. The numerical model accounts for the full interaction between the thermal effects caused by viscous heating and the momentum diffusion effects dictated by a shear rate and temperature-dependent constitutive model. The simulations have been performed for the commercial polymer Polyacetal POM-M90-44. Copyright © 2006 John Wiley & Sons, Ltd. [source] | |||||||||||||