Shapes

A general parametric form of a dynamic finite-element model of a linear elastic structure with small deformations is presented, with the model consisting of a set of scalar parameters multiplying element kernel matrices. The parameters of the finite-element model can represent stiffness and inertia properties, as well as axial forces if linearized buckling is assumed. Optimization of an orthogonality-based objective

In the present paper, a new approach for structural topology optimization based on dynamic implicit surface function (DISF) is proposed. DISF is used to describe the shape/topology of a structure, which is approximated in terms of the nodal values. Then, a relationship is established between the element stiffness and the values of the implicit surface function on its four nodes.

L'essai souhaite proposer quelques réflexions sur l’histoire de l’image en noir et blanc au début du XXème siècle: en concomitance avec l’importance toujours plus grande prise par l’image analogique dans l’univers de la culture visuelle, le noir et blanc s’est peu à peu affirmé comme le mode de vision privilégié de la modernité de début de siècle.

In this work, linear matrix inequality (LMI) methods are proposed for computationally efficient solution of damage detection problems in structures. The structural damage detection problem that is considered consists of estimating the existence, location, and extent of stiffness reduction in structures using experimental modal data. This problem is formulated as a convex optimization problem involving LMI constraints on the unknown structural stiffness parameters. LMI optimization problems have low computational complexity and can be solved efficiently using recently developed interior-point methods. Both a matrix update and a parameter update formulation of the damage detection is provided in terms of LMIs. The presence of noise in the experimental data is taken explicitly into account in these formulations. The proposed techniques are applied to detect damage in simulation examples and in a cantilevered beam test-bed using experimental data obtained from modal tests. [S0739-3717(0...

This paper presents matching and similarity evaluation meth- ods between two NURBS surfaces, and their application to copyright protection of digital data representing solids or NURBS surfaces. Two methods are employed to match ob- jects: the moment and the curvature methods. The moment method uses integral properties, i.e. the volume, the princi- pal moments of inertia and directions, to find the rigid body transformation as well as the scaling factor. The curva- ture method is based on the Gaussian and the mean cur- vatures to establish correspondence between two objects. The matching algorithms are applied to problems of copy- right protection. A suspect model is aligned to an original model through the matching methods so that similarity be- tween two models can be assessed to determine if the suspect model contains part(s) of the original model, which may be stored in an independent repository. Three types of tests, the weak, intermediate and strong tests, are proposed for similarity assessment between two objects. The weak and intermediate tests are performed at node points obtained through shape intrinsic wireframing. The strong test relies on isolated umbilical points which can be used as finger- prints of an object for supporting an ownership claim to the original model. The three tests are organized in two decision algorithms such that they produce systematic and statistical measures for a similarity decision between two objects in a hierarchical manner. Based on the systematic and statistical evaluation of similarity, a decision can be reached whether the suspect model is an illegal copy of the original model.

Driven by the trend of life-cycle design and sustainable production, an innovative project called self-reconfigurable intelligent swarm fixtures (SwarmItFIX) funded by the European Commission is being developed. The project investigates the application of robotic multi agent fixtures for the support of automotive and airplane body panels during their manufacturing and assembly processes. This paper addresses the exploration and development of the adaptable heads, which are the end-effector of the intelligent fixture. The head is able to adapt to the shape of the workpiece and freeze its shape after adaptation to provide stable support. Two kinds of head designs are discussed. The first design uses the pseudo-phase-change properties of a volume of bulk grains (metal sand) which can be clustered using a hydrostatic pressure to conform to a given workpiece shape. The second design investigated uses phase-change magneto-rheological (MR) fluid in a network of channels to allow and block ...

The increasing need to create high density and fine pitch electronic interconnections presents a number of challenges. The fatigue-induced solder joint failure of surface mounted electronic devices has become one of the most critical reliability issues in electronic packaging industry. Prediction of the shape of solder joint has drawn special attention in the development of electronic packaging for its practical engineering application. Many solder joint models have been developed based on energy minimization principle (Patra et al., 1995) or analytical method (Heinrich et al., 1993; Liedtke 1993). These methods are extensively utilized to the shape design of solder joint. However, it is important to find a suitable method in real application. In this study, an efficient numerical method used to predict the shapes of solder joint is investigated, and the results are compared with Surface Evolver program (Brakke, 1994). The changes of geometric shape with respect to different paramet...

We describe a web application that takes advantage of new computer vision techniques to allow the user to make searches based on visual similarity of color and texture related to the object of interest. We use a supervised neural network strategy to segment different classes of objects. A strength of this solution is the high speed in generalization of the trained neural networks, in order to obtain an object segmentation in real time. Information about the segmented object, such as color and texture, are extracted and indexed as text descriptions. Our case study is the online commercial offers domain where each offer is composed by text and images. Many successful experiments were done on real datasets in the fashion field.

Vengono presentate le modalità operative per la predisposizione di modelli tridimensionali esplorabili interattivamente.
La tecnica utilizzata si chiama texture baking e prevede la disposizione, nello spazio digitale 3D, di una serie di sorgenti luminose che interagiscono con i modelli in virtù delle caratteristiche fisiche e materiche.
Il lavoro è parte di una ricerca nazionale, denominata V.I.A. – Virtual Interactive Architecture, finanziata dal Ministero dell’Università e della Ricerca per il biennio 2005 – 2006. Vengono esplorate alcune tra le procedure oggi disponibili e vengono illustrati, nel dettaglio, i passi necessari per giungere al risultato.

Breakwaters obviously need to fulfill their function (protecting sensitive structures or cargo) while at the same time remaining intact and imposing manageable loads onto supporting structure. It goes without saying that such breakwaters should be cost effective, so that complex designs with extensive welding may not be preferable. In this paper the authors discuss green water loading on breakwaters for trading vessels like container ships which have forward speed and FPSOs which have zero speed. Different generic designs of V shape, vane type, double skin with and without holes, and forward sloping forecastle (whaleback deck) breakwaters applied to trading vessels are discussed. Guidelines for modeling green water horizontal loading on breakwaters of FPSOs and trading vessels using computational fluid dynamics (CFD) techniques are provided. The paper will also include a review of breakwater design criteria in rules and regulations.

The current trend in the magnetic storage industry is the reduction of the slider size and the height at which the slider flies over a rigid disk. Lower flying heights are achieved by miniaturizing sliders and reducing the normal load. In this paper, force scaling criteria are determined for 3370 and 3370K sliders that are dynamically loaded or operated in contact start/stop mode. Two forms of the generalized Reynolds equation (the first-order and continued fraction formulations) are incorporated into the analysis. The new scaling equation relates the steady-state flying height to design and operating parameters such as the disk velocity, normal load, ambient pressure, and the shape and dimension of the slider rail. The resulting quadratic equation contains two slider design dependent parameters which are calculated from two full scale numerical solutions to the generalized Reynolds equation for the slider design of interest. The new scaling equation accurately fits numerical and ex...

In this study, the effect of coarse aggregate shape characteristics on the compactability and microstructural properties of asphalt mixtures was virtually investigated using a discreet element method (DEM). Results reveal there is a statistically significant correlation between coarse aggregate flatness, elongation, roundness, and sphericity as shape descriptors and initial asphalt mixture density, as a compaction parameter. Analyses indicate that among all particle shape descriptors, only roundness and regularity had a statistically significant relation with compaction slope, and as the amount of roundness and regularity increase, the compaction slope decreases. Additionally, flatness and elongation values greater than 0.75 result in lower average coordination number values compared to those values less than 0.75. Results also indicate that although the probability density function (PDF) of low contact force highly depends on flatness, elongation and sphericity of particles, the PDF of high and very high contact forces is independent of the particle shape.

Measuring the similarity between two shapes or forms. Shape comparison. Shape description. Shapes of lines.  Shapes of surfaces. Shapes of solid objects. Voxelized objects. Polyhedra. Polygons. Storing shapes economically. Shape unicity.  Our work is described in these documents:

"*33. Bribiesca. E., y Guzmán, A. (1978) Shape Description and Shape Similarity Measurement for Two-dimensional Regions. Proceedings of the Fourth International Conference on Pattern Recognition, Kyoto, Japan. 608-612. Also available as Technical Report PR-78-18 (Orange Series 9, 166), IIMAS. Also: Journal of Geoprocessing, Vol. 1, No. 2, 129-144 (1980) (This journal no longer exists).

34. Bribiesca, E. and Guzmán, A. (1978) Shape numbers: a notation to describe pure form and to measure resemblance and difference among shapes. Technical Report PR-78-20 (Orange Series 178), IIMAS. In Spanish.

*39. Bribiesca, E. and Guzmán A. (1980) How to Describe Pure Forms and how to Measure Differences in Shapes using Shape Numbers. Invited paper to the IEEE Conference on Pattern Recognition and Image Processing. Chicago, USA. Also in Pattern Recognition, Vol 12, No. 2, 101-112. This article won the Seventh Annual Pattern Recognition Award, awarded by the Pattern Recognition Society in November 1981, as the best article of the year.

72. Guzmán A. (1987) Canonical Shape description for 3-D Stick Bodies. Technical Report ACA-254-87, MCC.

73. Guzmán, A. (1987) Shape Description in CYC. Technical Report AI-x-87(P), Artificial Intelligence Laboratory, MCC. MCC/ACA Confidential and Proprietary.

188. Ernesto Bribiesca, Adolfo Guzman. (2012) Enclosing Trees. Pattern Analysis and Applications 15:1-17.

192. Ernesto Bribiesca, Adolfo Guzman-Arenas, Luis A. Martínez. (2011) Representation of 3-D objects using enclosing trees. In Computational Intelligence Techniques in Handling Image Processing and Pattern Recognition, S. Ramakrishnan & Ibrahiem M. M. El Emary (Eds.), Lambert Academic Publishing, Germany. 227-252."

203. Luis Martinez, Ernesto Bribiesca, Adolfo Guzman. (2013). Voxel-based object representation by means of edging trees. 17th International Conference on Image Processing, Computer Vision, & Pattern Recognition, July 22-25, Las Vegas, USA.

204. Rodolfo Vilchis, Gilberto Martínez, Adolfo Guzman-Arenas (submitted). Visualization of the largest number of properties of multivariate objects using meta-dimensional grouping. Expert Systems with Applications.

More Info: The above papers can be downloaded from several places.
    * In academia.edu, under the page of "Adolfo Guzman Arenas" (https://ipn.academia.edu/AdolfoGuzman/ or academia.edu/AdolfoGuzman).  Search for "Adolfo Guzman Arenas".  You may be asked to suscribe. Try it, it is free!
* From my web page: http://alum.mit.edu/www/aguzman
* If above fails, write to me:  aguzman (at) ieee (dot) org  (that is @ all).
Also, those places will contain, probably, newer documents about the same topics.

The richness of natural images makes the quest for optimal representations in image processing and computer vision challenging. The latter observation has not prevented the design of image representations, which trade off between efficiency and complexity, while achieving accurate rendering of smooth regions as well as reproducing faithful contours and textures. The most recent ones, proposed in the past decade, share an hybrid heritage highlighting the multiscale and oriented nature of edges and patterns in images. This paper presents a panorama of the aforementioned literature on decompositions in multiscale, multi-orientation bases or dictionaries. They typically exhibit redundancy to improve sparsity in the transformed domain and sometimes its invariance with respect to simple geometric deformations (translation, rotation). Oriented multiscale dictionaries extend traditional wavelet processing and may offer rotation invariance. Highly redundant dictionaries require specific algorithms to simplify the search for an efficient (sparse) representation. We also discuss the extension of multiscale geometric decompositions to non-Euclidean domains such as the sphere or arbitrary meshed surfaces. The etymology of panorama suggests an overview, based on a choice of partially overlapping "pictures". We hope that this paper will contribute to the appreciation and apprehension of a stream of current research directions in image understanding.

In Japan, the cute aesthetic is abused by many organizations and for many purposes including police mascots, and warning signs for dangerous areas. Although using cute to motivate and inform might seem strange, cute does offer potential. Dr. Cheok and his team at the National University of Singapore argued that Japanese ‘kawaii’ embodies a special kind of cute design, which reduces fear and makes dreary information more acceptable and appealing. Various Japanese kawaii characters such as Hello Kitty and Pokemon have become popular all over the world. However, since few studies have focused on kawaii attributes, we systematically analyze the kawaii interfaces themselves: kawaii feelings caused by such attributes as shapes, colors, and materials. Our aim is to clarify a method for constructing a kawaii interface from the research results. Kawaii might be one important kansei value for future interactive systems and industrial products of Asian industries. We previously performed exper...

Free vibration analysis of a free inflated torus of circular cross-section is presented. The shell theory of Sanders, including the effect of pressure, is used in formulating the governing equations. These partial differential equations are reduced to ordinary differential equations with variable coefficients using complete waves in the form of trigonometric functions in the longitudinal direction. The assumed mode shapes are divided into symmetric and antisymmetric groups, each given by a Fourier series in the meridional coordinate. The solutions (natural frequencies and mode shapes) are obtained using Galerkin’s method and verified with published results. The natural frequencies are also obtained for a circular cylinder with shear diaphragm boundary condition as a special case of the toroidal shell. Finally, the effects of aspect ratio, pressure, and thickness on the natural frequencies of the inflated torus are studied.

In  this  paper,  we  published  a  survey  and  analysis  on  a  variety  of  the  various  strategies  for  maximizing  gain  and bandwidth. Because of their low profile, light weight, lowcost, compactness etc., Microstrip Patch Antenna (MPA) is widely used in  various  antenna  systems.  Owing  to  its  versatility,  the  patch  antenna  is  often  used  with  the  Microwave  IC  and  Monolithic Microwave IC's. But MPA’s lower gain and bandwidth is one of the key disadvantages. The researchers used various methods to achieve  enrichment,  such  as  in  the  microstrip  antenna  array,  superstrate  structure,  change  of  dielectric  material  and  partialremoval of substrates.

A new simple asymptotic mistuning model, which constitutes an extension of the well known fundamental mistuning model for groups of modes belonging to a modal family exhibiting a large variation of the tuned vibration characteristics, is used to analyze the effect of mistuning on the stability properties of aerodynamically unstable rotors. The model assumes that both the aerodynamics and the structural dynamics of the assembly are linear, and retains the first-order terms of a fully consistent asymptotic expansion of the tuned system where the small parameter is the blade mistuning. The simplicity of the model allows the optimization of the blade mistuning pattern to achieve maximum rotor stability. The results of the application of this technique to realistic welded-in-pair and interlock low-pressure-turbine rotors are also presented.

This paper discusses the development and application of a finite element method for determining the equilibrium shapes of solder joints which are formed during a surface mount reflow process. The potential energy governing the joint formation problem is developed in the form of integrals over the joint surface, which is discretized with the use of finite elements. The spatial variables which define the shape of the surface are expressed in a parametric form involving products of interpolation (blending) functions and element nodal coordinates. The nodal coordinates are determined by employing the minimum potential energy theorem. The method described in this paper is very general and can be employed for those problems involving the formation of three dimensional joints with complex shapes. It is well suited for problems in which the boundary region is not known a priori (e.g., “infinite tinning” problems). Moreover, it enables the user to determine the shape of the joint in parametr...

We compute the absorption efficiency (Qabs) of forsterite using the discrete dipole approximation (DDA) in order to identify and describe what characteristics of crystal grain shape and size are important to the shape, peak location, and relative strength of spectral features in the 8-40 μm wavelength range. Using the DDSCAT code, we compute Qabs for non-spherical polyhedral grain shapes with a_eff = 0.1 μm. The shape characteristics identified are: 1) elongation/reduction along one of three crystallographic axes; 2) asymmetry, such that all three crystallographic axes are of different lengths; and 3) the presence of crystalline faces that are not parallel to a specific crystallographic axis, e.g., non-rectangular prisms and (di)pyramids. Elongation/reduction dominates the locations and shapes of spectral features near 10, 11, 16, 23.5, 27, and 33.5 μm, while asymmetry and tips are secondary shape effects. Increasing grain sizes (0.1-1.0 μm) shifts the 10, 11 μm features systematica...

An adjoint-based shape optimization approach for supersonic turbine cascades is proposed for application to organic Rankine cycle (ORC) turbines. The algorithm is based on an inviscid discrete adjoint method and encompasses a fast look-up table (LuT) approach to accurately deal with real-gas flows. The turbine geometry is defined by adopting state-of-the-art parameterization techniques (NURBS), enabling to handle both global and local control of the shape of interest. A preconditioned steepest descent method has been chosen as gradient-based optimization algorithm to efficiently search for the nearest minimum. The potential of the optimization approach is first verified by application on the redesign of an existing converging–diverging turbine nozzle operating in thermodynamic regions characterized by relevant real-gas effects. A significant efficiency improvement and a more uniform flow at the blade outlet section are achieved, with expected beneficial effects on the aerodynamics o...

The purpose of this study is to determine the consumer product perception towards preferred brand of processed cheese. Specifically, to investigate the perception towards the price, product satisfaction, visual impact, and brand of processed cheese. Components like brand, shape, packaging material, weight, shop where consumers purchase processed cheese were also considered for finding the association between the product preferences. Data were collected through questionnaire from 400 individuals. The results of the study found a significant association between consumer product preference and gender, age, income, educational qualification, family type, brand, shape, packaging material, weight and shop where consumer purchase processed cheese.