Search results for "computational"
showing 10 items of 5884 documents
An ensemble analysis of electromyographic activity during whole body pointing with the use of support vector machines.
2011
Import JabRef | WosArea Life Sciences and Biomedicine - Other Topics; International audience; We explored the use of support vector machines (SVM) in order to analyze the ensemble activities of 24 postural and focal muscles recorded during a whole body pointing task. Because of the large number of variables involved in motor control studies, such multivariate methods have much to offer over the standard univariate techniques that are currently employed in the field to detect modifications. The SVM was used to uncover the principle differences underlying several variations of the task. Five variants of the task were used. An unconstrained reaching, two constrained at the focal level and two …
Modeling Human Endometrial Decidualization from the Interaction between Proteome and Secretome
2011
Context: Decidualization of the human endometrium, which involves morphological and biochemical modifications of the endometrial stromal cells (ESCs), is a prerequisite for adequate trophoblast invasion and placenta formation. Objective: This study aims to investigate the proteome and secretome of in vitro decidualized ESCs. These data were combined with published genomic information and integrated to model the human decidualization interactome. Design: Prospective experimental case–control study. Setting: A private research foundation. Patients: Sixteen healthy volunteer ovum donors. Intervention: Endometrial samples were obtained, and ESCs were isolated and decidualized in vitro. Main Ou…
Temporal Structure of Human Gaze Dynamics Is Invariant During Free Viewing.
2015
We investigate the dynamic structure of human gaze and present an experimental study of the frequency components of the change in gaze position over time during free viewing of computer-generated fractal images. We show that changes in gaze position are scale-invariant in time with statistical properties that are characteristic of a random walk process. We quantify and track changes in the temporal structure using a well-defined scaling parameter called the Hurst exponent, H. We find H is robust regardless of the spatial complexity generated by the fractal images. In addition, we find the Hurst exponent is invariant across all participants, including those with distinct changes to higher or…
Does Bold Emphasis Facilitate the Process of Visual-Word Recognition?
2014
AbstractThe study of the effects of typographical factors on lexical access has been rather neglected in the literature on visual-word recognition. Indeed, current computational models of visual-word recognition employ an unrefined letter feature level in their coding schemes. In a letter recognition experiment, Pelli, Burns, Farell, and Moore-Page (2006), letters in Bookman boldface produced more efficiency (i.e., a higher ratio of thresholds of an ideal observer versus a human observer) than the letters in Bookman regular under visual noise. Here we examined whether the effect of bold emphasis can be generalized to a common visual-word recognition task (lexical decision: “is the item a wo…
Impact of Thoracic Endografting on the Hemodynamics of the Native Aorta: Pre- and Postoperative Assessments of Wall Shear Stress and Vorticity Using …
2021
Purpose To quantify the hemodynamic consequences of thoracic endovascular aortic repair (TEVAR) by comparing the preoperative and postoperative wall shear stress (WSS) and vorticity profiles on computational fluid dynamics (CFD) simulations. Materials and Methods The pre- and postoperative computed tomography (CT) scans from 20 consecutive patients (median age 69 years, range 20–87) treated for different thoracic aortic pathologies (11 aneurysms, 5 false aneurysms, 3 penetrating ulcers, and 1 traumatic aortic rupture) were segmented to construct patient-specific CFD models using a meshless code. The simulations were run over the cardiac cycle, and the WSS and vorticity values measured at th…
InCREDulity in Artificial Societies
2021
This paper describes an artificial society in which the simulated agents behave and interact based on a computational architecture informed by insights from one of the leading social psychological theories in the scientific study of secularization and religion: “credibility-enhancing displays” (or CREDs) theory. After introducing the key elements of the theory and outlining the computational architecture of our CRED model, we present some of our initial simulation results. These efforts are intended to advance the quest within social simulation for more authentic artificial societies and more plausible human-like agents with complex interactive and interpretative capacities.
Modeling Radicalization and Violent Extremism
2020
Given public anxiety about radicalization and violent extremism, it is not surprising that these topics have grabbed the attention of so many scholars in recent years. However, some have expressed concern over the fact that only a few studies in this relatively new field contain empirical data or systematic data analysis or develop causal models of the mechanisms generating these phenomena. We believe that computational modeling and simulation techniques can make a significant contribution to this scientific literature and eventually provide new tools for improving policy analysis. Here we briefly describe (1) an integrative theory of violent extremism proposed by Kruglanski and colleagues …
Modelling terror management theory: computer simulations of the impact of mortality salience on religiosity
2017
ABSTRACTThis article outlines the development – and reports on the experimental findings – of two computational models designed to simulate the dynamic systems and behavioural patterns identified and clarified by research on terror management theory. The causal architectures of these models are informed by empirical research on the effects of mortality salience on “religiosity” (and vice versa). They are also informed by research on the way in which perception of personal and environmental hazards activate evolved cognitive and coalitional precautionary systems that can intensify anxiety-alleviating behaviours such as imaginative engagement with supernatural agents postulated within a relig…
Computational Science of Religion
2021
This article provides a basic overview of the most common methods of computer modelling and simulation that are currently being used to study religion. It focuses on the use (and illustrates the value) of system dynamics models, agent-based models, including game theory and multi-agent artificial intelligence models, and artificial neural networks. General use case examples are provided, and considerations for future research are discussed. We conclude by encouraging scholars interested in religion and related fields to incorporate techniques from the computational science of religion into their collaborative methodological toolkits.
A Full-Scale Agent-Based Model to Hypothetically Explore the Impact of Lockdown, Social Distancing, and Vaccination During the COVID-19 Pandemic in L…
2021
Background The COVID-19 outbreak, an event of global concern, has provided scientists the opportunity to use mathematical modeling to run simulations and test theories about the pandemic. Objective The aim of this study was to propose a full-scale individual-based model of the COVID-19 outbreak in Lombardy, Italy, to test various scenarios pertaining to the pandemic and achieve novel performance metrics. Methods The model was designed to simulate all 10 million inhabitants of Lombardy person by person via a simple agent-based approach using a commercial computer. In order to obtain performance data, a collision detection model was developed to enable cluster nodes in small cells that can b…