scholarly journals Adaptation of Symmetric Positive Semi-Definite Matrices for the Analysis of Textured Images

2018 ◽  
Vol 18 (1) ◽  
pp. 51-68
Author(s):  
Adib Akl
Keyword(s):  
Adaptive Algorithm ◽  
Local Structure ◽  
Structural Information ◽  
Local Variation ◽  
Local Orientation ◽  
Accurate Analysis ◽  
Structure Estimation ◽  
Gradient Fields ◽  
Degree Of Anisotropy ◽  
The Way

Abstract This paper addresses the analysis of textured images using the symmetric positive semi-definite matrix. In particular, a field of symmetric positive semi-definite matrices is used to estimate the structural information represented by the local orientation and the degree of anisotropy in structured and sinusoid-like textured images. In order to ensure faithful local structure estimation, an adaptive algorithm for the regularization of the extent of gradient fields smoothing is proposed. Results obtained on different texture samples show the strength of the proposed method in accurately representing the local variation of orientations in the underlying textured images, which paves the way towards an accurate analysis of the texture structures.

scholarly journals Using adjoint sensitivity as a local structure function in variational data assimilation

2001 ◽  
Vol 8 (6) ◽  
pp. 347-355 ◽  
Author(s):  
G. Hello ◽  
F. Bouttier
Keyword(s):  
Data Assimilation ◽  
Structure Function ◽  
Local Structure ◽  
Initial Conditions ◽  
Storm Track ◽  
Variational Data Assimilation ◽  
Sensitive Area ◽  
Adjoint Sensitivity ◽  
Weather Events ◽  
Gradient Fields

Abstract. One approach recently proposed in order to improve the forecast of weather events, such as cyclogenesis, is to increase the number of observations in areas depending on the flow configuration. These areas are obtained using, for example, the sensitivity to initial conditions of a selected predicted cyclone. An alternative or complementary way is proposed here. The idea is to employ such an adjoint sensitivity field as a local structure function within variational data assimilation, 3D-Var in this instance. Away from the sensitive area, observation increments project on the initial fields with the usual climatological (or weakly flow-dependent, in the case of 4D-Var) structure functions. Within the sensitive area, the gradient fields are projected using all the available data in the zone, conventional or extra, if any. The formulation of the technique is given and the approach is further explained by using a simple 1D scheme. The technique is implemented in the ARPEGE/IFS code and applied to 11 FASTEX (Fronts and Atlantic Storm-Track Experiment) cyclone cases, together with the targeted observations performed at the time of the campaign. The new approach is shown to allow for the desired stronger impact of the available observations and to systematically improve the forecasts of the FASTEX cyclones, unlike the standard 3D-Var.

scholarly journals Diffraction/Scattering Tomography on multi-phase crystalline/amorphous materials

2014 ◽  
Vol 70 (a1) ◽  
pp. C139-C139 ◽  
Author(s):  
Michelle Alvarez-Murga ◽  
Pierre Bleuet ◽  
Christophe Lepoittevin ◽  
Nathalie Boudet ◽  
Gaston Gabarino ◽  
...  
Keyword(s):  
Amorphous Materials ◽  
Structural Information ◽  
Local Variation ◽  
X Rays ◽  
Complex Materials ◽  
Diffraction Scattering ◽  
Invasive Approach ◽  
Non Invasive ◽  
Phase Selectivity ◽  
Multi Phase

By suitably combining diffraction/scattering and tomography (DSCT), it is possible to access to selective submicron 2D/3D structural and micro-structural information, which cannot be obtained from separate, independent diffraction and tomography experiments. DSCT is used to discriminate between multi-phase crystalline and amorphous materials, especially when the similarities in densities limit the use of other methods. In addition, this method is sensitive to local variation of the crystalline state, texture, grain size or strains inside the object and can allow simultaneous 3D mappings of such properties. The DSCT phase-selectivity can be easily combined with fluorescence and absorption for added chemical and density resolution allowing multi-modal analyses. As samples can be used in their original state, this method can be applied without cutting or polishing them. Moreover the setup can be adapted with specific sample environments in order to monitor phase and microstructure evolution as a function of an externally controlled parameter with a non-invasive approach. After a first report on in 1998 [1], since 2008 capabilities of DSCT have been demonstrated using x-rays on complex materials as diverse as biological tissue, pigments, Portland cements, Carbon-based materials, Uranium-based nuclear fuel, Ni/Al2O3 catalysts or amorphous systems [2]. More recently, the technique has evolved towards quantitative characterization of the microstructure and stress/strain through either Rietveld or Peak Profile analyses and also pair distribution function techniques (PDF) and their application to nanostructured materials [3]. In this poster contribution, we briefly review the principle and methodology of pencil-beam based x-ray DSCT which is two-fold: (i) selective structural imaging and (ii) extraction of selective scattered patterns of ultra-minor phases.

scholarly journals Topological flatness of local models for ramified unitary groups. II. The even dimensional case

2013 ◽  
Vol 13 (2) ◽  
pp. 303-393 ◽  
Author(s):  
Brian D. Smithling
Keyword(s):  
Local Structure ◽  
Unitary Groups ◽  
Dimensional Case ◽  
Shimura Varieties ◽  
Local Models ◽  
Admissible Set ◽  
The Way ◽  
Moduli Problems

AbstractLocal models are schemes, defined in terms of linear-algebraic moduli problems, which are used to model the étale-local structure of integral models of certain$p$-adic PEL Shimura varieties defined by Rapoport and Zink. In the case of a unitary similitude group whose localization at${ \mathbb{Q} }_{p} $is ramified, quasi-split$G{U}_{n} $, Pappas has observed that the original local models are typically not flat, and he and Rapoport have introduced new conditions to the original moduli problem which they conjecture to yield a flat scheme. In a previous paper, we proved that their new local models are topologically flat when$n$is odd. In the present paper, we prove topological flatness when$n$is even. Along the way, we characterize the$\mu $-admissible set for certain cocharacters$\mu $in types$B$and$D$, and we show that for these cocharacters admissibility can be characterized in a vertexwise way, confirming a conjecture of Pappas and Rapoport.

Aeroacoustical Coupling and Its Structural Effects on a PWR Steam Line: Part 2 — Vibroacoustical Analysis of Pipe Shell Deformations

2002 ◽  
Author(s):  
Se´bastien Caillaud ◽  
Christophe Lambert ◽  
Jean-Paul Devos ◽  
Philippe Lafon
Keyword(s):  
Energy Transfer ◽  
Finite Elements ◽  
Modal Analysis ◽  
Steam Line ◽  
Accurate Analysis ◽  
Analysis Of Dispersion ◽  
Fully Coupled ◽  
Finite Elements Model ◽  
Acoustical Energy ◽  
The Way

A pure tone phenomenon has been observed at 460 Hz in a PWR steam line. The acoustical energy has been identified to be generated in an open gate valve. The objective here is to understand the way of energy transfer from the fluid to the main pipe using two fully coupled methods. The first method consists in a modal analysis of the line using a fluid-structure finite elements model. The second one is based on the analysis of dispersion diagrams derived from the local equations of cylindrical shells filled with fluid. The way of energy transfer in transverse acoustical waves induced combined flexion-ovalisation deformations of the pipe is highlighted using both methods. The dispersion diagrams allow a fast and accurate analysis. The modal analysis using a finite elements model may complete the first one with quantitative data.

Integration Between Urban Planning and Natural Hazards For Resilient City

2018 ◽  
pp. 591-630
Author(s):  
Şule Tüdeş ◽  
Kadriye Burcu Yavuz Kumlu ◽  
Sener Ceryan
Keyword(s):  
Earth Sciences ◽  
Urban Planning ◽  
Land Use Planning ◽  
Site Selection ◽  
Planning Process ◽  
Accurate Analysis ◽  
The Earth ◽  
Analysis And Synthesis ◽  
Planning Processes ◽  
The Way

Analyses and syntheses conducted before the urban planning process are significant. Accurate analysis and synthesis enable to determine proper site selection and the proper site selection is the basis of a sustainable urban plan. In this sense, fundamental analysis inputs of the proper site selection could be indicated as the related parameters of the earth sciences. The interpretation of these inputs require the essential analyses and syntheses of initially the geological and geotechnical research with geophysics, tectonic, topography, mineral and natural resources, hydrogeology, geomorphology and engineering geology. Synthesis maps composed of these inputs especially provide guides for natural thresholds consisting of landslide, flood, inundation, earthquake etc. for land use planning and site selection parts in the urban planning processes. In this regard, this chapter of the book contains the relation between the earth sciences parameters with the urban planning and the way these parameters lead the way of urban planning processes.

COVARIATION ANALYSIS OF LOCAL AMINO ACID SEQUENCES IN RECURRENT PROTEIN LOCAL STRUCTURES

2005 ◽  
Vol 03 (06) ◽  
pp. 1391-1409 ◽  
Author(s):  
LU-YONG WANG
Keyword(s):  
Protein Folding ◽  
Amino Acid ◽  
Local Structure ◽  
Structural Information ◽  
Statistical Significance ◽  
Amino Acid Sequences ◽  
Structural Motifs ◽  
Systematic Analysis ◽  
Local Structures ◽  
Covariation Analysis

Local structural information is supposed to be frequently encoded in local amino acid sequences. Previous research only indicated that some local structure positions have specific residue preferences in some particular local structures. However, correlated pairwise replacements for interacting residues in recurrent local structural motifs from unrelated proteins have not been studied systematically. We introduced a new method fusing statistical covariation analysis and local structure-based alignment. Systematic analysis of structure-based multiple alignments of recurrent local structures from unrelated proteins in representative subset of Protein Databank indicates that covarying residue pairs with statistical significance exist in local structural motifs, in particular β-turns and helix caps. These residue pairs are mostly linked through polar functional groups with direct or indirect hydrogen bonding. Hydrophobic interaction is also a major factor in constraining pairwise amino acid residue replacement in recurrent local structures. We also found correlated residue pairs that are not clearly linked with through-space interactions. The physical constrains underlying these covariations are less clear. Overall, covarying residue pairs with statistical significance exist in local structures from unrelated proteins. The existence of sequence covariations in local structural motifs from unrelated proteins indicates that many relics of local relations are still retained in the tertiary structures after protein folding. It supports the notion that some local structural information is encoded in local sequences and the local structural codes could play important roles in determining native state protein folding topology.

Integration Between Urban Planning and Natural Hazards for Resilient City

2019 ◽  
pp. 1256-1294
Author(s):  
Şule Tüdeş ◽  
Kadriye Burcu Yavuz Kumlu ◽  
Sener Ceryan
Keyword(s):  
Earth Sciences ◽  
Urban Planning ◽  
Land Use Planning ◽  
Site Selection ◽  
Planning Process ◽  
Accurate Analysis ◽  
The Earth ◽  
Analysis And Synthesis ◽  
Planning Processes ◽  
The Way

Analyses and syntheses conducted before the urban planning process are significant. Accurate analysis and synthesis enable to determine proper site selection and the proper site selection is the basis of a sustainable urban plan. In this sense, fundamental analysis inputs of the proper site selection could be indicated as the related parameters of the earth sciences. The interpretation of these inputs require the essential analyses and syntheses of initially the geological and geotechnical research with geophysics, tectonic, topography, mineral and natural resources, hydrogeology, geomorphology and engineering geology. Synthesis maps composed of these inputs especially provide guides for natural thresholds consisting of landslide, flood, inundation, earthquake etc. for land use planning and site selection parts in the urban planning processes. In this regard, this chapter of the book contains the relation between the earth sciences parameters with the urban planning and the way these parameters lead the way of urban planning processes.

Integration Between Urban Planning and Natural Hazards For Resilient City

2018 ◽  
pp. 1157-1196
Author(s):  
Şule Tüdeş ◽  
Kadriye Burcu Yavuz Kumlu ◽  
Sener Ceryan
Keyword(s):  
Earth Sciences ◽  
Urban Planning ◽  
Land Use Planning ◽  
Site Selection ◽  
Planning Process ◽  
Accurate Analysis ◽  
The Earth ◽  
Analysis And Synthesis ◽  
Planning Processes ◽  
The Way

Analyses and syntheses conducted before the urban planning process are significant. Accurate analysis and synthesis enable to determine proper site selection and the proper site selection is the basis of a sustainable urban plan. In this sense, fundamental analysis inputs of the proper site selection could be indicated as the related parameters of the earth sciences. The interpretation of these inputs require the essential analyses and syntheses of initially the geological and geotechnical research with geophysics, tectonic, topography, mineral and natural resources, hydrogeology, geomorphology and engineering geology. Synthesis maps composed of these inputs especially provide guides for natural thresholds consisting of landslide, flood, inundation, earthquake etc. for land use planning and site selection parts in the urban planning processes. In this regard, this chapter of the book contains the relation between the earth sciences parameters with the urban planning and the way these parameters lead the way of urban planning processes.

A combined LX-NMR and molecular dynamics investigation of the bulk and local structure of ionic liquid crystals

Soft Matter ◽  
2019 ◽  
Vol 15 (22) ◽  
pp. 4486-4497 ◽  
Author(s):  
Maria Enrica Di Pietro ◽  
Tommaso Margola ◽  
Giorgio Celebre ◽  
Giuseppina De Luca ◽  
Giacomo Saielli
Keyword(s):  
Molecular Dynamics ◽  
Ionic Liquid ◽  
Liquid Crystals ◽  
Nmr Spectroscopy ◽  
Molecular Dynamics Simulations ◽  
Local Structure ◽  
Structural Information ◽  
Ionic Liquid Crystals ◽  
Dynamics Simulations ◽  
Unique Power

The unique power of NMR spectroscopy in anisotropic media (LX-NMR) as a tool to obtain local and bulk structural information, combined with the effectiveness of molecular dynamics simulations at the atomistic level, shows very attractive potentialities for the study of Ionic Liquid Crystals.

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