Search results for " Modeling"
showing 10 items of 2411 documents
Non-Desarguian geometries and the foundations of geometry from David Hilbert to Ruth Moufang
2004
Abstract In this work, we study the development of non-Desarguian geometry from David Hilbert to Ruth Moufang. We will see that a geometric model became a complicated interrelation between algebra and geometry.
Matrix Shuffle- Exchange Networks for Hard 2D Tasks
2021
Convolutional neural networks have become the main tools for processing two-dimensional data. They work well for images, yet convolutions have a limited receptive field that prevents its applications to more complex 2D tasks. We propose a new neural model, called Matrix Shuffle-Exchange network, that can efficiently exploit long-range dependencies in 2D data and has comparable speed to a convolutional neural network. It is derived from Neural Shuffle-Exchange network and has O(log N) layers and O(N ^ 2 log N) total time and O(N^2) space complexity for processing a NxN data matrix. We show that the Matrix Shuffle-Exchange network is well-suited for algorithmic and logical reasoning tasks on …
A holistic approach to design for 4D Printing
2019
Invented in 1983, as a rapid prototyping process, additive manufacturing (AM) is nowadays considered as a manufacturing process almost in the same way as conventional processes. For example, parts obtained by AM are found in aircraft structures. This AM evolution is mainly due to the shape complexity allowed by the process. The driving forces behind this evolution include: the development of various techniques on the layer-wise manufacturing principle and the improvement both in quantity and quality of the range of materials that can be processed. Many other AM techniques and materials continue to emerge. In the wake of the AM (usually referred to as 3D printing) another mode of manufacturi…
Monte Carlo tests of theoretical predictions for critical phenomena: still a problem?
2000
Two Monte Carlo studies of critical behavior in ferromagnetic Ising models are described: the first one deals with the crossover from the Ising class to the mean field class, when the interaction range increases. The second study deals with the finite size behavior at dimensionalities above the marginal dimension where Landau theory applies. The numerical results are compared to pertinent theoretical predictions, and unsolved problems are briefly described.
UML-Based Metamodeling for Information System Engineering and Evolution
2003
In modelers’ practice metamodels have become the core of UML-based metamodeling environments: metamodels form the basis of application domain descriptions, and they are instantiated into models. In the context of information system engineering and interoperability, we have developped two operations on metamodels: metamodel integration and measure of semantical distance between metamodels. In this paper, we explore application of these operations to information systems’ evolution.
Improved Global-Local Method for Ultrasonic Guided Wave Scattering Predictions in Composite Waveguides and Defects
2023
Abstract As structures increase in complexity, in the use of high-performing materials and designs, their health assessment becomes increasingly challenging. Ultrasonic guided waves (UGWs) have shown to be very promising in the inspection of large (i.e. aerospace components) attenuating (i.e. composite materials) structures and have been successfully employed for damage detection in a variety of fields. The intrinsic complex nature of UGWs, due to their dispersive behavior, combined with the structural complexity of the applications, though, makes the interpretation of UGW inspections very challenging. Numerical simulations of UGW propagation become crucial to this end and have been address…
Funcionamiento familiar, autoestima y consumo de sustancias en adolescentes: un modelo de mediación
2007
Objective This research analyzes the direct and indirect relationships among family functioning, multidimensional self-esteem (family, academic, social, and physical self-esteem) and substance use. Materials and methods The study participants were composed of two independent samples of Spanish adolescents who provided information during the 2003-2004 academic year (n1 = 414, Castilla and Leon; n2 = 625, Comunidad Valenciana). The statistical analyses were carried out using structural equation modelling and the procedure of mediation effects analysis (Holmbeck, 1997). Results Results showed a significant mediational effect of self-esteem on the relation between family functioning and adolesc…
Healthy Behavior as a Mediator in the Relationship Between Optimism and Life Satisfaction in Health Sciences Students: A Cross-Sectional Study
2021
Aleksandra M Rogowska,1 Paweł F Nowak,2 Aleksandra Kwaśnicka1 1Institute of Psychology, University of Opole, Opole, Poland; 2Faculty of Physical Education and Physiotherapy, Opole University of Technology, Opole, PolandCorrespondence: Aleksandra M RogowskaInstitute of Psychology, University of Opole, ul. Staszica 1, Room 312, Opole, 45-052, PolandTel +48 604732259Email arogowska@uni.opole.plPurpose: This study examines the indirect relationship between optimism and life satisfaction via healthy behavior among health sciences students.Participants and Methods: The cross-sectional study involved 349 health sciences students, including 58% of women, ranging in age between…
Using meta-analytic path analysis to test theoretical predictions in health behavior: An illustration based on meta-analyses of the theory of planned…
2016
Abstract Objective Synthesizing research on social cognitive theories applied to health behavior is an important step in the development of an evidence base of psychological factors as targets for effective behavioral interventions. However, few meta-analyses of research on social cognitive theories in health contexts have conducted simultaneous tests of theoretically-stipulated pattern effects using path analysis. We argue that conducting path analyses of meta-analytic effects among constructs from social cognitive theories is important to test nomological validity, account for mediation effects, and evaluate unique effects of theory constructs independent of past behavior. We illustrate o…
Parenting Stress, Mental Health, Dyadic Adjustment: A Structural Equation Model
2017
Objective: In the 1st year of the post-partum period, parenting stress, mental health, and dyadic adjustment are important for the wellbeing of both parents and the child. However, there are few studies that analyze the relationship among these three dimensions. The aim of this study is to investigate the relationships between parenting stress, mental health (depressive and anxiety symptoms), and dyadic adjustment among first-time parents. Method: We studied 268 parents (134 couples) of healthy babies. At 12 months post-partum, both parents filled out, in a counterbalanced order, the Parenting Stress Index-Short Form, the Edinburgh Post-natal Depression Scale, the State-Trait Anxiety Invent…