Set Of Substructures Research Articles

Reduced order modeling of modular parameter dependent structures based on proper orthogonal decomposition and mesh tying

AbstractA model order reduction technique in combination with mesh tying is used to efficiently simulate many different structures that are assembled from a set of substructures. The stiffness matrices of the substructures are computed separately and assembled into a global stiffness matrix with tied contact formulation. Reducing the degrees of freedom of each substructure with a projection‐based model order reduction technique further decreases the computational time. The mode matrices that project the system into the low‐dimensional subspace are computed for each module separately with proper orthogonal decomposition and the method of snapshots. For the development and optimization of new construction strategies for fiber‐reinforced concrete, many different combinations of the modules have to be tested. The mechanical behavior of these modules depends on a set of parameters. Here the parameters are the fiber directions for transversely isotropic material behavior and parameters that describe the shape of the module. The sensitivity of the model order reduction technique to parameter changes requires a mode adaption technique to obtain reasonable results. Mode matrices for any parameters are computed by interpolating in a tangent space to the Grassmann manifold.

UNIVERSAL SOFTWARE SYSTEM “STADYO” FOR THE NUMERICAL SOLUTION OF LINEAR AND NONLINEAR PROBLEMS OF THE FIELD THEORY, STATICS, STABILITY AND DYNAMICS OF SPATIAL COMBINED SYSTEMS: GENERAL PARAMETERS AND SUPERELEMENTAL FEATURES

The distinctive paper presents the general papers of the science-based universal software system “STADYO” intended for the numerical solution of stationary and nonstationary problems of field theory, analy-sis of static, temperature and dynamic stress-strain state (SSS), stability and strength of arbitrary combined me-chanical systems (massive-shell-lamellar-membrane-rod with “rigid” bodies, fluid cavities and internal bonds, isotropic and orthotropic materials) into a flat axis, axisymmetric and three-dimensional linear and nonlinear formulations. The composition of the “STADYO” software system is briefly described; in terms of its theoretical foundations, the main provisions and matrix relationships of the superelement method (which is known to be one of the most effective ways to increase the universality and increase the computational efficiency of finite element algorithms) are presented, as well as methods for dynamic synthesis of substructures and submodelling. The su-perelement algorithm is also extended to solving a system of linear equations at each step of the implicit scheme of direct integration of the equations of motion, and at each iteration in the calculation of natural oscillations; however, an alternative and more efficient approach consists in constructing special superelement algorithms based on the direct condensation of the equations of motion and ideologically close to the method of dynamic synthesis of substructures. The submodelling options, in particular, are important for the refined analysis of the three-dimensional SSS of heavily loaded component parts of the objects under consideration. In general, the presentation of the global design model of the system as a set of substructures is also very convenient for its de-scription and creates the prerequisite for the creation (application) of effective pre- and postprocessor software. The paper also provides information on verification and experience in the use of the “STADYO” software sys-tem, as well as prospects for development.

Robustness Diagram with Loop and Time Controls for System Modelling and Scenario Extraction with Energy System Applications

In this research, we introduce an extension of Robustness Diagrams for modelling complex systems such as energy systems. We provide a construction scheme of this extension for the inclusion of looped and time-dependent substructures for an effective modelling framework. The latter set of substructures is introduced in this work as “reset-bound subsystems”. We introduce a scenario extraction algorithm to obtain behavioral profiles from the models. Lastly, we apply our scheme to create a model of a real-world energy system and use the proposed algorithm to extract a scenario describing one process done by the system being modelled.

A Query Approximating Approach Over RDF Graphs

Regardless of the knowledge structure lack about Resource Description Framework (RDF) data, difficulties, principally, occur in specifying and answering queries. Approximate querying is the solution to find relevant information by getting a set of sub structures (e.g. sub graphs) matching the query. Approaches based on the structure and others based on semantic, marginalized the common meaning between concepts in its computing. In this paper in order to improve the approximation by introducing the meaning similarity between components in the query and RDF components is proposed, getting better need satisfaction. The meaning similarity measure can be calculated using WordNet and used in all steps of the query answering process. In addition, other important properties in the approximation level calculation between query paths and RDF paths are considered; besides indexing and optimizations strategies are performed. Answers are a set of sub graphs ranked in decreasing order on its matching degree. Experiments are conducted within real RDF dataset.

Component mode synthesis approaches for quantum mechanical electrostatic analysis of nanoscale devices

In this paper, two component mode synthesis (CMS) approaches, namely, the fixed interface CMS approach and the free interface CMS approach, are presented and compared for an efficient solution of 2-D Schrodinger-Poisson equations for quantum-mechanical electrostatic analyses of nanostructures and devices with arbitrary geometries. In the CMS approaches, a nanostructure is divided into a set of substructures or components and the eigenvalues (energy levels) and eigenvectors (wave functions) are computed first for all the substructures. The computed wave functions are then combined with constraint or attachment modes to construct a transformation matrix. By using the transformation matrix, a reduced-order system of the Schrodinger equation is obtained for the entire nanostructure. The global energy levels and wave functions can be obtained with the reduced-order system. Through an iteration procedure between the Schrodinger and Poisson equations, a self-consistent solution for charge concentration and potential profile can be obtained. Numerical calculations show that both CMS approaches can largely reduce the computational cost. The free interface CMS approach can provide significantly more accurate results than the fixed interface CMS approach with the same number of retained wave functions in each component. However, the fixed interface CMS approach is more efficient than the free interface CMS approach when large degrees of freedom are included in the simulation.

Automatic segmentation of tissue sections using the multielement information provided by LA-ICP-MS imaging and k-means cluster analysis

Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) is an established and powerful tool to analyse the distribution of elements in tissue sections. Among other applications, the technique is expected to play a central role in the understanding of normal and pathological element distributions in brain tissue. In order to interpret the distribution of elements such as the bio-metals Cu, Zn, Fe and Mn and proceed to an element-based comparison between groups of samples, it is necessary to anatomically parcel the tissue section into regions-of-interest and to average element signals across these regions. This categorization, also termed segmentation, can be done manually, but the support of automated procedures is highly desirable, especially in order to (1) identify groups of pixels with similar elemental fingerprint, termed clusters, and to determine which degree of discrimination is reasonable; (2) segment anatomical structures known to exhibit substructure but without clearly defined borders, such as the healthy cortex, zones of tumours or ischemic lesions, in an observer-independent way; and (3) to investigate correlation between the distribution of elements in tissue and phenomena which incorporate contributions from several elements in a convoluted way, such as the origin of contrast in magnetic resonance imaging (MRI) experiments. The multi-parametric information provided by LA-ICP-MS lends itself naturally to multivariate analysis. This study provides a new way to synthesise the information distributed over many element images by demonstrating the possibility to segment tissue sections into biologically meaningful substructures. This data-driven, observer-independent categorization was based on k-means clustering. The optimal number of clusters was determined based on the silhouette method. Segmentation of healthy tissue resulted in a set of substructures in perfect congruence to the anatomical architecture. Segmentation of ischemic lesions identified a number of regions with different fingerprints of C, P, Fe, Cu and Zn deposits. Clustering provides a promising way of combining the information present in several element images and reveals structure which is not entirely present in any isolated image. As a useful by-product of this study we have found a promising method for investigating the optimal line length within the process of image reconstruction from the continuous stream of raw data points. Images were characterized by their tensor of inertia, in image- as well as in Fourier dual-space ( k-space) and changes in the ratio of the intrinsic moments of inertia or the orientation of the principal axes were found to closely describe the optimum orientation. The first results look very encouraging, but the method must be extensively tested before it can be used as an automatic procedure. In conclusion, cluster analysis of mass spectrometric imaging data allows one to define the fingerprint element distribution of different anatomically or functionally distinct regions and opens a new way for the study of correlation between the element distribution and related phenomena.

10.1007/s11497-008-2001-y

Wave equations make it possible to ascribe the quantum numbers to leptons theoretically. Minimal extension of the groups describing stable leptons led to three new types of groups. Each of them has an appropriate structure invariant ±1.0 and its own set of substructures having a physical interpretation in terms of stable leptons. The properties of the above-mentioned groups allow one to generate new types of equations and to relate them with two doublets (particle-antiparticle) of massive, charged unstable leptons and a doublet of massive unstable neutrinos.

Polyadic Dynamic Logics for HPSG Parsing

Head-driven phrase structure grammar (HPSG) is one of the most prominent theories employed in deep parsing of natural language. Many linguistic theories are arguably best formalized in extensions of modal or dynamic logic (Keller, Feature logics, infinitary descriptions and grammar, 1993; Kracht, Linguistics Philos 18:401---458, 1995; Moss and Tiede, In: Blackburn, van Benthem, and Wolther (eds.) Handbook of modal logic, 2006), and HPSG seems to be no exception. Adequate extensions of dynamic logic have not been studied in detail, however; the most important aspect is the reference to sets of substructures. In this paper, an adequate extension is identified, and some important results are established: Satisfiability is highly undecidable, and model checking is shown to be in EXPTIME and PSPACE-hard. A fragment with polynomial time model checking procedures is identified; it is shown to cover considerable fragments of HPSG.

Structure quantum numbers and unstable leptons

Wave equations make it possible to ascribe the quantum numbers to leptons theoretically. Minimal extension of the groups describing stable leptons led to three new types of groups. Each of them has an appropriate structure invariant ±1.0 and its own set of substructures having a physical interpretation in terms of stable leptons. The properties of the above-mentioned groups allow one to generate new types of equations and to relate them with two doublets (particle-antiparticle) of massive, charged unstable leptons and a doublet of massive unstable neutrinos.

Large and frequently occurring substructures in organic compounds obtained by library search of infrared spectra

Comparing the infrared spectrum of a compound whose chemical structure is unknown with the spectra of a library is a routinely used method to obtain information about the unknown structure. The resulting hitlist contains compounds exhibiting the most similar spectra. If the unknown is not contained in the library, a method based on the maximum common substructure concept can be applied to extract common structural features from the hitlist structures. The result is a set of substructures that are characteristic for the query structure. This approach has been applied to infrared spectra from a series of model compounds and has been compared with information obtained from mass spectra by the same procedure. A complementary chemometric method for evaluating spectral hitlists is principal component analysis of spectral and structural data.

Maximum Common Substructures of Organic Compounds Exhibiting Similar Infrared Spectra

Information about the unknown chemical structure of an organic compound can be obtained by comparing the infrared spectrum with the spectra of a spectral library. The resulting hitlist contains compounds exhibiting the most similar spectra. A method based on the maximum common substructure concept has been developed for an automatic extraction of common structural features from the hitlist structures. A set of substructures is derived that are characteristic for the query structure. Results can be used as structural restrictions in isomer generation.

Family and migration.

This paper examines the effects of international migration on internal family structure, as well as the adaptation and integration of families into receiving countries. The importance of the role and function of the family in migration research can be examined from 3 angles: theoretical, methodological, and empirical (that is, the societal relevance of family in migration). A renewed theoretical perspective views the family in the sending country instead of the individual as the focus of attention, and reveals that 1) migration patterns are not exclusively among the poor or unemployed; 2) migration is not always for the benefit of the immigrant; and 3) migration should be studied as a process, not as a result. Recent studies show that 1) family or kinship migration is increasingly important and that families help new migrants adapt to the receiving country, both emotionally and financially; 2) family and kinship ties tend to become consolidated in the receiving country; and 3) the family helps migrants cope with stress caused by the migration experience. Studies on families' preservation of culture and adaptation of culture and behavior have gone from 1) descriptive to analytical and, 2) focusing on the receiving society to focusing on the strategies used by immigrants (from value-conformity to an individualistic-situation approach). Migration also causes changes in family organization and functioning, which should be studied as an internal process inside the family and as complex group. Within the family are 3 sets of substructures which change during the process of adaptation and/or assimilation to/into the receiving society: 1) the husband-wife relationship, 2) the parent-child relationship, and 3) the relationship among siblings.