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Auteur Y. Sasaki
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Application of wavelet transform for extracting edges of paddy fields from remotely sensed images / T. Ishida in International Journal of Remote Sensing IJRS, vol 25 n° 2 (January 2004)
Titre : Application of wavelet transform for extracting edges of paddy fields from remotely sensed images Type de document : Article/Communication Auteurs : T. Ishida, Auteur ; S. Itagaki, Auteur ; Y. Sasaki, Auteur ; H. Ando, Auteur Année de publication : 2004 Article en page(s) : pp 347 - 357 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Photogrammétrie numérique
[Termes IGN] contour
[Termes IGN] détection de contours
[Termes IGN] filtrage numérique d'image
[Termes IGN] image SPOT
[Termes IGN] polygone
[Termes IGN] transformation en ondelettes
Résumé : (Auteur) For geographical information systems (GIS) to be useful in the management of Japanese paddy fields, it is vital to be able to prepare base maps that define sections of field. We attempted to prepare a base map by detecting the edges of submerged paddy fields from a SPOT image with the use of multiresolution wavelet transform. The raw image of SPOT band 3 was decomposed into a low frequency approximation image and a set of high frequency detailed images to five levels, and then reconstructed. The reconstructed image at the fifth level was obtained from all of the high frequency images except for the low frequency approximation image. The image reconstructed up to full scale was then applied to a zero-crossing scheme and three post-processings-line thinning, removal of isolated pixels, and connection of pixels with their neighbours in order to obtain clear edges. The spatial features of the image indicating the edges obtained by multi-resolution wavelet transform were compared quantitatively with those obtained by using a difference of Gaussian (DOG) filter. The multi-resolution wavelet transform was better than the DOG filter in that the base map obtained by the wavelet transform method represented a 'field block', which is typically composed of 10 holdings of paddy field, more precisely than with the DOG filter, and in that the number of open polygons on this map was smaller, indicating that the wavelet transform method is more suitable for producing the base map in GIS for the management of paddy fields. Numéro de notice : A2004-054 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/0143116031000115120 En ligne : https://doi.org/10.1080/0143116031000115120 Format de la ressource électronique : URL article Permalink :
in International Journal of Remote Sensing IJRS > vol 25 n° 2 (January 2004) . - pp 347 - 357[article]
Code-barres Cote Support Localisation Section Disponibilité 080-04021 RAB Revue Centre de documentation En réserve L003 Exclu du prêtVariational methods in geosciences / Y. Sasaki (1986)
Titre : Variational methods in geosciences : Proceedings of the International Symposium held at the University of Oklahoma, Norman, Oklahoma, USA, 15 - 17 October 1985 Type de document : Actes de congrès Auteurs : Y. Sasaki, Éditeur scientifique ; L. White, Éditeur scientifique ; M.M. Zaman, Éditeur scientifique ; T. Gal-Chen, Éditeur scientifique ; et al., Auteur Congrès : Congrès: International Symposium Variational methods in geosciences (15 - 17 octobre 1985; Norman, Oklahoma - Etats-Unis), Auteur Editeur : Amsterdam [Pays Bas] : Elsevier Année de publication : 1986 Collection : Developments in Geomathematics num. 5 Importance : 309 p. Format : 17 x 25 cm ISBN/ISSN/EAN : 978-0-444-42697-0 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Statistiques
[Termes IGN] analyse numérique
[Termes IGN] filtre de Kalman
[Termes IGN] géostatistique
[Termes IGN] météorologie
[Termes IGN] océanographie
[Termes IGN] optimisation (mathématiques)
[Termes IGN] variabilité
Index. décimale : CG1985 Actes de congrès en 1985 Résumé : (Auteur) Variational methods, one of the most classic and elegant methods in physical and mathematical sciences, have been developed within the last few decades as powerful tools of optimization and numerical analysis.
In the area of the geosciences, which includes meteorology, oceanography, hydrology, geophysics and seismology, the variational methods have been extensively used to interpret and assimilate geoscientific data and to simulate geoscientific phenomena. It was timely to call for a meeting to provide an opportunity for researchers in different disciplines of the geosciences to discuss problems of mutual interest.
The first symposium on Variational Methods in Geosciences was thus organized and held in Norman on October 15-17, 1985. Papers which were presented were stimulating and informative, with a desire to have a second symposium in about two years expressed by some researchers who participated in the first symposium.
There were a number of outstanding papers presented in the symposium. We therefore publish them so that others in the geosciences and in other disciplines may benefit.
The symposium was well organized, due to the remarkable efforts by the local and international organizing committee members cited earlier. We owe the success of the symposium to the organizations whose support was essential to bring together such a broad spectrum of scientists and engineers.
Finally, we thank the personnel at CIMMS who have contributed much to this project. Thanks are particularly due to Ms. Constance White, without whose abilities this work would have suffered, and to Ms. Lynda McGinley, Conference Specialist, who was responsible for the preliminary arrangements. We also thank Ms. Chris Heath and Mrs. Judy Johnston for their time and energy.
Note de contenu : I. METEOROLOGY AND OCEANOGRAPHY
The Application of Variational Methods to Initialization on the Sphere - R.W. DALEY
Application of Optimal Control to Meteorological Problems - 0. TALAGRAND
A Review of Variational and Optimization Methods in Meteorology - I.M. NAVON
Use of Adjoint Equations for Assimilation of Meteorological Observations by Barotropic Models - PH. COURTIER
The Variational Four-Dimensional Assimilation of Analyses Using Quasigeostrophic Models as Constraints - JOHN C. DERBER
Evaluation of a Multivariate Variational Assimilation of Conventional and Satellite Data for the Diagnosis of Cyclone Systems - GARY L. ACHTEMEIER, H.T. OCHS, III, S.Q. KIDDER and R.W. SCOTT
The Variational Inverse Method for the General Circulation in the Ocean - CHRISTINE PROVOST
Variational Analysis of Wind Field and Geopotential at 500 MB - F.-X. LE DIMET and J. SEGOT
Design of a Three-Dimensional Global Atmospheric Prediction Model by a Variational Method - A. KASAHARA.
Variational Implicit Normal Mode Initialization for NWP Models - CLIVE TEMPERTON
Formulation of Normal Modes and Nonlinear Initialization for Limited-Area Models - R. JUVANON DU VACHAT and B. URBAN
II. METEOROLOGY AND REMOTE SENSING
Sequential Estimation and Satellite Data Assimilation in Meteorology and Oceanography - M. GHIL.
The Use of Adjoint Equations to Solve Variational Adjustment Problems Subject to Vorticity Conser-vation Constraints - J.M. LEWIS
Variational Modification of the 3D-Wind Field - MICHAEL HANTEL
A Four-Dimensional Analysis - ROSS N. HOFFMAN
Variational Initialization and Determination of Weighting Factors - CHUNG-YI TSENG
Partial Spline Models for the Estimation of the Three Dimensional Atmospheric Temperature Distribution from Satellite Radiance Data and Tropopause Height Information - GRACE WAHBA.
The Retrievel of Moving Waves from Remotely-Sensed Atmospheric Data - DEREK M. CUNNOLD and CHOWEN CHOU WEY
Impact of Doppler Wind Analysis Weights on Three Dimensional Airflow and Diagnosed Precipitation in a Thunderstorm - C.L. ZIEGLER
III. GENERAL MATH THEORY
Remarks on Systems with Uncomplete Data - J.L. LIONS
Two Dimensional Kalman Filtering and Assimilation of Wind Profiler Data - D.F. PARRISH and S.E. COHN
Bayesian Optimal Analysis for Meteorological Data - R.J. PURSER
Relationships Between Statistical and Deterministic Methods of Data Assimilation - W.C. THACKER
Assimilation of Dynamical Data in a Limited Area Model - F.-X. LE DIMET. and A. NOUAILLER
Variational Principles and Adaptive Methods for Complex Flow Problems - J. TINSLEY ODEN, T. STROUBOULIS, and PH. DEVLOO
Penalty Variational Formulation of Viscous Incompressible Fluid Flows - J.N. REDDY
A New Combination Method of Boundary Type Finite Elements and Boundary Elements for Wave Diffraction and Refraction - K. KASHIYAMA, M. KAWAHARA, and H. SAKURAI
The Numerical Analysis of Two-Dimensional Steady Free Surface Flow Problems - TSUKASA NAKAYAMA and MUTSUTO KAWAHARA.
Variational Principles in Continuum Mechanics and Their Application in the Study of Propagating Discontinuities - J. TURSKI
Comparison of Variational Methods for the Solution of the Dynamic Group Diffusion Problem : One Dimensional Case - E. DEL VALLE, J.C. DIAZ, and D. MEADE
Variational Methods for Fluid Flow in Porous Media - R.E. EWING
A Finite Element Simulator for Incompressible Two-Phase Flow - G. CHAVENT, G. COHEN, and J. JAFFRE
Simulation of Waterflooding in Heterogeneous, Compressible, and Irregularly Shaped Reservoirs -A.R. KUKRETI, M.M. ZAMAN, F. CIVAN, Y.R. PERERA, and G.C. BISWAS
Data Structures and Algorithms for Self Adaptive Local Grid Refinement - J.C. DIAZ and D.B. NORTH
On the Modeling of Soil Liquefaction by Finite Element Method - M.M. ZAMAN and J.G. LAGUROS
Response of Circular Plates Resting on Homogeneous and Isotropic Halfspace - I.U. MAHMOOD
Evolution of Local Amplitude in Trains of Shear Flow Instability Waves - J.M. RUSSELL.
Numéro de notice : 16658 Affiliation des auteurs : non IGN Thématique : MATHEMATIQUE Nature : Actes Permalink :
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