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Wyszukujesz frazę "Shape" wg kryterium: Temat


Tytuł:
Recognizing Sharp Features of 2-D Shapes
Autorzy:
Gewali, L.
Scanlan, J. P.
Powiązania:
https://bibliotekanauki.pl/articles/226950.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
shape recognition
shape similarity
boundary approximation
shape decomposition
shape simplification
Opis:
We present an efficient algorithm for recognizing and extracting sharp-features from complex polygonal shapes. The algorithm executes in O(n²) time, where n is the number of vertices in the polygon. Sharp-feature extraction algorithms can be useful as a pre-processing step for measuring shape-similarity between polygonal shapes.
Źródło:
International Journal of Electronics and Telecommunications; 2010, 56, 2; 153-156
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanical properties and advanced subjects in shape memory alloys and polymers
Autorzy:
Matsui, R.
Takeda, K.
Tobushi, H.
Pieczyska, E. A.
Powiązania:
https://bibliotekanauki.pl/articles/281495.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
shape memory alloy
shape memory polymer
functionally-graded shape memory material
shape memory composite
Opis:
Advanced subjects in mechanical properties of shape memory alloys and polymers are discussed. In the subloop loading under a stress-controlled condition of the shape memory alloy, the transformation-induced stress relaxation appears due to variation in temperature. The enhancement of corrosion and corrosion fatigue life of the shape memory alloy is discussed. The development of a functionally-graded shape memory alloy and polymer is expected to obtain better performance. Three-way motion appears in the shape memory composite with the shape memory alloy and polymer.
Źródło:
Journal of Theoretical and Applied Mechanics; 2018, 56, 2; 447-456
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of Zernike Moments to the problem of General Shape Analysis
Autorzy:
Frejlichowski, D.
Powiązania:
https://bibliotekanauki.pl/articles/206416.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
Zernike moments
general shape analysis
shape description
Opis:
The Zernike Moments (ZM) have been successfully applied to the problem of shape recognition. Their properties allow for solving some fundamental problems in this task. Amongst them the most important one is the invariance to rotation, scaling, translation, and reflectional symmetry. Moreover, the obtained representation can vary according to the level of generalisation of a shape. For this reason in the paper the application of the ZM to the problem of General Shape Analysis (GSA) is proposed and experimentally investigated. The GSA problem is similar to the recognition and retrieval of shapes. However, only the most general classes of shapes (e.g. square, triangle, circle, ellipse) are assumed to perform the role of the basic templates. Moreover, the processed object does not have to belong to any of the template classes, but may be only similar to one of them. This enables us to receive the most general information about a shape, e.g. how square, triangular, round, elliptical, etc. it is. In the paper, in order to evaluate the Zernike Moments applied to the problem of GSA, the performance of this shape descriptor is compared with the results provided by nearly two hundred humans and collected by means of appropriate inquiry forms.
Źródło:
Control and Cybernetics; 2011, 40, 2; 515-526
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Use of Resistance Sensors to Measurement of Shape Charge Parameters
Autorzy:
Wiśniewski, A.
Powiązania:
https://bibliotekanauki.pl/articles/358447.pdf
Data publikacji:
2011
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
sensors
shape charge
explosives
shape charge jet
Opis:
In the article different methods of measurement of the collapsing liner parameters and the formation of the shape charge jet by resistance sensor which was placed inside the shape charge are presented. The speed and acceleration change while reducing of resistance sensor length for shape charge in casing and without it for the different angles of the shape charge liner is analyzed. The resistance sensor placed in the shape charge liner permitted to register the parameters which cannot be obtained by the X-ray impulse apparatus. By the resistance sensor placed at the angle to the shape charge axis or perpendicular to the internal surface of the shape charge liner, the reducing shape charge liner parameters were registered. The resistance sensor placed on the shape charge axis enabled to register the parameters of the jet forming in the shape charge. In case of placing of resistance sensor on shape charge casing, the graphs become more stable in comparison with the graphs obtained when resistance sensor was placed inside shape charge.
Źródło:
Central European Journal of Energetic Materials; 2011, 8, 2; 131-141
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Shape derivatives for general objective functions and the incompressible Navier-Stokes equations
Autorzy:
Schmidt, S.
Schulz, V.
Powiązania:
https://bibliotekanauki.pl/articles/969869.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
shape optimization
shape derivative
Navier-Stokes
adjoint calculus
Opis:
The aim of this paper is to present the shape derivative for a wide array of objective functions using the incompressible Navier-Stokes equations as a state constraint. Most real world applications of computational fluid dynamics are shape optimization problems in nature, yet special shape optimization techniques are seldom used outside the field of elliptic partial differential equations and linear elasticity. This article tries to be self contained, also presenting many useful results from the literature. We conclude with a comparison of different objective functions for the shape optimization of an obstacle in a channel, which can be done quite conveniently when one knows the general form of the shape gradient.
Źródło:
Control and Cybernetics; 2010, 39, 3; 677-713
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison beech wood tension strength parallel to grain of cylindrical samples with conical and funnel tapering versus standard rectangular cross section samples
Autorzy:
Karwat, Zbigniew
Koczan, Grzegorz
Rębkowski, Bartłomiej
Kozakiewicz, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/2201354.pdf
Data publikacji:
2022
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
tension strength
cylindrical sample
conical shape
funnel shape
rectangular shape
turn-milling
beech Wood
Opis:
In this paper, the influence of shape samples on tension strength parallel to grain of beech wood have been analyzed. The cylindrical samples with conical tapering and with funnel tapering were used. Both types of cylindrical samples were compared with one-sided tapered standard samples with a rectangular cross-section. Experimental outcome indicates that cylindrical samples have higher tension strength than rectangular standard ones. Whereas shape of tapering in cylindrical samples (conical or funnel) was not statistically significant. Furthermore the presentation and reanalysis of data concerning use of cylindrical samples made of seven domestic wood species from the doctoral dissertation were performed. Comparison of that data with source data about tension strength of standard rectangular samples, have proven higher tension strength parallel to grain of cylindrical samples.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2022, 65, 209; Art. no. 1644-3985.403.11
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On stability analysis in shape optimisation : critical shapes for Neumann problem
Autorzy:
Dambrine, M.
Sokolowski, J.
Żochowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/970525.pdf
Data publikacji:
2003
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
optymalizacja kształtu
analiza stabilności
gradient kształtu
shape optimisation
stability analysis
shape gradient
shape Hessian
Opis:
The stability issue of critical shapes for shape optimization problems with the state function given by a solution to the Neumann problem for the Laplace equation is considered. To this end, the properties of the shape Hessian evaluated at critical shapes are analysed. First, it is proved that the stability cannot be expected for the model problem. Then, the new estimates for the shape Hessian are derived in order to overcome the classical two norms-discrepancy well know in control problems, Malanowski (2001). In the context of shape optimization, the situation is similar compared to control problems, actually, the shape Hessian can be coercive only in the norm strictly weaker with respect to the norm of the second order differentiability of the shape functional. In addition, it is shown that an appropriate regularization makes possible the stability of critical shapes.
Źródło:
Control and Cybernetics; 2003, 32, 3; 503-528
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pre-shape calculus and its application to mesh quality optimization
Autorzy:
Luft, Daniel
Schulz, Volker
Powiązania:
https://bibliotekanauki.pl/articles/2183466.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
shape optimization
mesh quality
mesh deformation method
shape calculus
Opis:
Deformations of the computational mesh, arising from optimization routines, usually lead to decrease of mesh quality or even destruction of the mesh. We propose a theoretical framework using pre-shapes to generalize the classical shape optimization and calculus. We define pre-shape derivatives and derive corresponding structure and calculus theorems. In particular, tangential directions are featured in pre-shape derivatives, in contrast to classical shape derivatives, featuring only normal directions. Techniques from classical shape optimization and calculus are shown to carry over to this framework. An optimization problem class for mesh quality is introduced, which is solvable with the use of pre-shape derivatives. This class allows for simultaneous optimization of the classical shape objectives and mesh quality without deteriorating the classical shape optimization solution. The new techniques are implemented and numerically tested for 2D and 3D.
Źródło:
Control and Cybernetics; 2021, 50, 3; 263--301
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simultaneous shape and mesh quality optimization using pre-shape calculus
Autorzy:
Luft, Daniel
Schulz, Volker
Powiązania:
https://bibliotekanauki.pl/articles/2183472.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
shape optimization
mesh quality
mesh deformation method
shape calculus
Opis:
Computational meshes arising from shape optimization routines commonly suffer from decrease of mesh quality or even destruction of the mesh. In this work, we provide an approach to regularize general shape optimization problems to increase both shape and volume mesh quality. For this, we employ pre-shape calculus as established in Luft and Schulz (2021). Existence of regularized solutions is guaranteed. Further, consistency of modified pre-shape gradient systems is established. We present pre-shape gradient system modifications, which permit simultaneous shape optimization with mesh quality improvement. Optimal shapes to the original problem are left invariant under regularization. The computational burden of our approach is limited, since additional solution of possibly larger (non-)linear systems for regularized shape gradients is not necessary. We implement and compare pre-shape gradient regularization approaches for a 2D problem, which is prone to mesh degeneration. As our approach does not depend on the choice of metrics representing shape gradients, we employ and compare several different metrics.
Źródło:
Control and Cybernetics; 2021, 50, 4; 473--520
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Shape sensitivity analysis of time-dependent flows of incompressible non-Newtonian fluids
Autorzy:
Sokołowski, J.
Stebel, J.
Powiązania:
https://bibliotekanauki.pl/articles/206105.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
shape optimization
shape gradient
incompressible viscous fluid
Navier-Stokes equations
Opis:
We study the shape differentiability of a cost function for the flow of an incompressible viscous fluid of power-law type. The fluid is confined to a bounded planar domain surrounding an obstacle. For smooth perturbations of the shape of the obstacle we express the shape gradient of the cost function which can be subsequently used to improve the initial design.
Źródło:
Control and Cybernetics; 2011, 40, 4; 1077-1097
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The use of optical scanner in measurements of complex shape objects
Autorzy:
Juras, B.
Szewczyk, D.
Sładek, J.
Powiązania:
https://bibliotekanauki.pl/articles/102029.pdf
Data publikacji:
2013
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
optical scanner
complex shape elements
reference model
shape compatibility assessment
Opis:
The paper presents the topic of measurements of simple and complex shaped ob¬jects. Optical measurement method with the use of laser scanner was presented, as well as the issues of geometry measurements and shape assessment by the use of the strategy of fitting to standard elements. The construction of a reference model for given elements by measuring of malformed elements was shown. The given examples confirmed the usefulness of presented optical method in the assessment of shape com¬patibility of real element with nominal one, as well as in the assessment of objects’ deformation.
Źródło:
Advances in Science and Technology. Research Journal; 2013, 7, 19; 48-54
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bend loss fiber optics design based on sinusoidal and ellipse configurations
Autorzy:
Mohd Arif, Noor Azie Azura
Burhanuddin, Dilla Durhya
Shaari, Sahbudin
Ehsan, Abang Annuar
Powiązania:
https://bibliotekanauki.pl/articles/2033968.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
sinusoidal shape
ellipse shape
bending loss
number of turns
curvature radius
Opis:
Bending losses in optical fibers comprise one of the extrinsic attenuations that contribute to optical loss and they are essential for optical fiber bending sensor applications. This work investigated the optical loss in a standard single-mode step-index fiber optics due to fiber bending at 1550 nm wavelength. Variations in macro-bending loss with curvature radius and turn number have been measured. Curvature radius and turn number are examined for sinusoidal and elliptical shaped bending configurations. It has been found that the loss increases as the bending radius and number of turns increase. The result also showed that elliptical shaped bending configuration produced more loss in contrast to that of sinusoidal shaped at bending angles of 180° and 360°. The study on the macro-bending loss in terms of curvature radius and turn number for both elliptical and sinusoidal shaped bending configurations is beneficial for future fiber optic sensor applications.
Źródło:
Optica Applicata; 2021, 51, 3; 309-320
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of Hurwitz – Radon matrices in shape representation
Autorzy:
Jakóbczak, D.
Powiązania:
https://bibliotekanauki.pl/articles/117952.pdf
Data publikacji:
2010
Wydawca:
Polskie Towarzystwo Promocji Wiedzy
Tematy:
shape representation
curve interpolation
contour reconstruction
shape coefficient
Hurwitz-Radon matrices
Opis:
Computer vision needs suitable methods of shape representation and contour reconstruction. One of them, invented by the author and called method of Hurwitz-Radon Matrices (MHR), can be used in representation and reconstruction of shapes of the objects in the plane. Proposed method is based on a family of Hurwitz-Radon (HR) matrices. The matrices are skew-symmetric and possess columns composed of orthogonal vectors. Shape is represented by the set of nodes. It is shown how to create the orthogonal and discrete OHR operator and how to use it in a process of shape representation and reconstruction. MHR method is interpolating the curve point by point without using any formula or function.
Źródło:
Applied Computer Science; 2010, 6, 1; 63-74
1895-3735
Pojawia się w:
Applied Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic programming approach to shape optimization
Autorzy:
Fulmański, P.
Nowakowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/206302.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
dynamic programming
shape optimization
Opis:
We provide a dynamic programming approach through the level set setting to structural optimization problems. By constructing a dual dynamic programming method we provide the verification theorem for optimal and "−optimal solutions of shape optimization problem.
Źródło:
Control and Cybernetics; 2014, 43, 3; 379-401
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On existence of shape optimization for a p-Laplacian equation over a class of open domains
Autorzy:
Guo, Bao-Zhu.
Yang, D. H.
Powiązania:
https://bibliotekanauki.pl/articles/206462.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
Laplacian
shape optimization
existence
Opis:
In this paper, we introduce four new classes of open sets in general Euclidean space RN. It is shown that every such class of open sets is compact under the Hausdorff distance. The result is applied to a shape optimization problem of p-Laplacian equation. The existence of the optimal solution is presented.
Źródło:
Control and Cybernetics; 2014, 43, 1; 15-31
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł

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