Size Of Structural Elements Research Articles

Architectural Design of Earthquake and Wind Resisting Structure

This paper describes a structural analysis computer program. Written specifically for architects, the program is used to determine the structure a building requires to resist lateral loads. The program overcomes an existing lack of information on possible configurations and sizes of structural elements to resist earthquake and wind load. It enables many design options to be considered, and increases the likelihood of the final choice of structural system and configuration best integrating with the total design. Uses of the program in undergraduate teaching, and the preparation of architectural design guides are discussed.

Texture analysis of technegas lung ventilation images

Technegas lung ventilation images sometimes have 'hot spots', particularly in patients with respiratory disease. A novel technique is presented for quantifying this 'spottiness' using morphological texture analysis. A set of 32 images from patients with various respiratory diseases is studied. Images are filtered at a range of scales using morphological opening, and the slopes of image metrics versus structuring element size are used as texture parameters. The results are compared with the opinions of three experienced nuclear medicine physicians who have classified the images into two groups, 'spotty' and 'non-spotty', and have ranked the former. For the spotty images, the computer and observer ranks are compared; the highest correlation is rs = 0.66 (p = 0.01) for a single parameter, and rs = 0.71 (p < 0.01) for a combination of two parameters. Using a pair of parameters, 83% and 90% correct classification rates are obtained for the spotty and non-spotty classes, respectively. It is concluded that these texture parameters provide a useful measure of image spottiness, and it is demonstrated that this technique is superior to previously published methods. The practical value of the technique is illustrated using two applications.

Logic gate implementation for gray-scale morphology

In this paper, we show that the direct logic gate implementation of gray-scale morphology can be modified using threshold decomposition principle. The resulting new architecture has the advantage that the number of logic levels is not sensitive to structuring element size increases, yet it requires much less number of logic gates than a previously reported architecture having the same advantage.

Morphological shape and region description

Abstract A new algorithm for multiscale description of binary digital regions is given. A region is represented by a growing sequence of subsets approximating it; each approximation is obtained from the previous one by addition of the opening by a structuring element chosen in a finite family. The structuring elements vary in size and shape, and are chosen at each step according to two criteria: largest structuring element size and greatest increment in the size of the approximation. The algorithm satisfies meaningful algebraic properties and converges to a final result in a bounded number of steps. It also allows an economical representation of shape in terms of structuring elements, and so it can be applied in binary image coding.

Analysis of texture in macroradiographs of osteoarthritic knees, using the fractal signature

Texture of regions of macroradiographs (*5) of six normal and five osteoarthritic knee joints, taken on a high resolution microfocal X-ray unit, are examined using mathematical morphology. Radiographs of bones are two-dimensional projections of attenuation coefficient through the three-dimensional (3D) joint structure. Visible texture represents the summation of the attenuation from numerous thin plates of bone. Where there is no organization in the trabeculae, resultant radiographs approximate a fractal surface. Varying structuring element size in mathematical morphology allows estimation of fractal dimension over a range of resolution. Variation of fractal dimension with resolution, the fractal signature, indicates how images deviate from fractal surfaces. By correct choice of structuring element, a texture analysis method using the fractal signature has been developed, tolerant to changes in image acquisition and digitization.

Dimensional-structural relationships of the strength of two-phase polycrystalline inorganic materials

Examples of experimental relationships between the strength of two-phase inorganic materials and the shape and sizes of structure elements were studied, as well as dimensional parameters, such as the value of the mean free path between particles and the mean distance between particles. The structural condition for achieving the maximum values of strength of two-phase metallic, cermet and ceramic materials with a high content of the second phase has been established and experimentally verified. An approximate analysis of the dislocation structure of interfaces is made and their contribution to the strengthening of two-phase materials with a disperse and microlayer structure is shown.

Dimension-structure dependences for the strength of two-phase polycrystalline inorganic materials

Examples are considered of experimental dependences of the strength of two-phase inorganic materials on the shape and size of structural elements, and also dimensional parameters: the mean value of the free path and the mean distance between particles. The structural condition for achieving the maximum strength values for two-phase metallic, cermet, and ceramic materials with a high second phase content is established and substantiated by experiment. An approximate analysis of the dislocation structure of interphase boundaries is performed and their contribution to strengthening of two-phase materials with a dispersed and microlayered structure is demonstrated.

Decomposition of gray-scale morphological structuring elements

Mathematical morphology has been developed recently for many applications in image processing and analysis. Most image processing architectures adapted to morphological operations use structuring elements of limited size. Implementation difficulties arise when an algorithm requires the use of a large size structuring element. In this paper we present techniques for decomposing big grayscale morphological structuring elements into combined structures of segmented small components. According to mathematical morphology properties, such decomposition allows us to equate morphological operations on big structuring elements with operations on decomposed small structuring components. The decomposition is suitable for parallel pipelined architecture. This technique will allow full freedom for users to design any kind and any size of gray-scale morphological structuring element.

An Integrated Machining Process Design Simulator for the Optimal Design of Face Milling Systems

An Integrated Machining Process Design Simulator (IMPDS) is developed and applied as a general tool for the design of face milling systems. The simulator includes four modules to accommodate the important factors that affect face milling operations. These modules are: a general purpose finite element program to analyze structural characteristics, a mechanistic face milling force module for both open-loop and closed-loop cutting force simulations, a machinability module to evaluate cutting process performance, and an efficient optimization module to automate the design process. The design variables, constraints, and objective function of the entire system include structural element size, shape, and weight, cutting forces and vibrations, and other machinability measures including tool life, metal removal rate, and surface finish. Several examples are included to demonstrate the capability of IMPDS in the machining system design process.

Investigation of the effect of spherulite size on the strength and deformation characteristics of isotactic polypropylene films

Experiments on isotactic polypropylene films were used to study the relationship between parameters of the tensile stress/strain diagram and the size of supermolecular structure elements (spherulites). Certain qualitative and quantitative laws were established. Test results showed that the spherulite size affects almost all the mechanical properties studied (except the recrystallization stress), especially the parameters characterizing the deformation of polypropylene. Microscopic examination showed that the rupture of spherulitic structures in most cases takes place along the spherulite boundaries. Such ruptures can be attributed to the unavoidable presence of large defects between spherulites in the initial polymer films.

Untersuchungen der inneren Struktur interstellarer Wolken. I. Photographisch‐photometrische Methode

AbstractFor investigation of the inner structure of interstellar clouds with aid of the photographic photometry the dust density in the clouds must be higher than a minimum value depending on the diameter of the clouds and on the size of the structure elements to be recognized. There is also a highest value of the density for these observations depending on the extent of the clouds, on the spatial distribution of A‐type stars, and on the used observing instrument. The calculations were done for an instrument of about 24 inches aperture (Schmidt‐camera of the Jena Observatory).The smallest clouds, which can be investigated with an instrument of this aperture and reasonable demands of the size of structure elements, must have a diameter of 15 pc. The mean dust density of this cloud has to be about 4 · 10−25 g cm−3. The density of bigger clouds can vary within a determined interval, e.g. 10−25 g cm−3 &lt; gD &lt; 10−24 g cm−3 for D = 50 pc. The considerations were done for clouds with constant density and with a density gradient depending on the distance to the centre of the cloud.

The influence of packing density on the small-angle X-ray scattering of a polydisperse colloid system

The influence of packing density of a polydisperse colloid system on the shape of the small-angle scattering curve and on the intensity of scattered radiation was studied experimentally. Twelve specimens of a finely divided alumina hydrate were prepared, their thickness being constant and their packing density increasing from 0.026 to 0.89. The shape of scattering curves did not vary much from one specimen to the other, as predicted by several authors. The intensity of scattered radiation was destroyed by the inter-particle interference as if the mass absorption coefficient was increased by a constant value. The average particle size of structural elements, as obtained from scattering curves by methods of Hosemann and Porod, increased with the packing density; this could be explained by the association of the particles in the process of pressing the material. The average size as obtained by the X-ray method is in rather good agreement with the average size of structural elements as shown by electron micrograph.