Search results for "Simulation."
showing 10 items of 4779 documents
Biomechanical analysis of anticipation of elite and inexperienced goalkeepers to distance shots in handball
2012
AbstractThe objective of this study was to evaluate the anticipation time and kinematic factors in the movement ofgoalkeepers’ center of mass when making a long-distance throw in handball. The sample group was composed of 14goalkeepers and field players. A force platform was used to measure the force of the goalkeepers’ reaction movements, whilethe throwers’ movements were recorded with high-speed cameras. The expert goalkeepers began to move 193 ± 67 ms beforethe ball was released, with a 67% success rate of interception. The inexperienced goalkeepers began their movement 209 ±127 ms with a 24% success rate. The time taken by expert goalkeepers to begin a vertical movement of their CM, rel…
Adsorption of the herbicide 4-chloro-2-methylphenoxyacetic acid (MCPA) by goethite.
2014
Interaction between the goethite surface and 4-chloro-2-methylphenoxyacetic acid (MCPA) herbicide was studied using density functional theory (DFT) calculations combined with molecular dynamics (MD). The important step made here lies in the use of a periodic DFT method enabling the study of a mineral surface of different protonation states, in strong contrast with previous molecular modeling studies limited to single protonation state corresponding to the point of zero charge. Different surface OH groups and MCPA proton states were used to mimic the strong effects of pH on the outer- and inner-sphere surface complexes that are theoretically possible, together with their binding energies, an…
The influence of the mean stress on fatigue life of 10HNAP steel under random loading
2001
Abstract This paper contains the results of uniaxial random load fatigue tests with different mean values performed on 10HNAP steel specimens. The experimental fatigue life was compared with the life determined according to different methods of amplitude transformation of the cycles. Cycles were counted with the rain flow algorithm and damage was cumulated with the Palmgren–Miner hypothesis. It has been shown that in the case of “symmetric” stress histories with zero expected values, the mean values of selected cycles do not strongly influence the calculated fatigue life and transformation of the cycle amplitudes; hence, no mean stress correction for cycle mean values different from zero is…
SIMULATING DEMOGRAPHY AND HUMAN DEVELOPMENT DYNAMICS
2014
[EN] A deterministic/stochastic model in which the demographic and the well-being subsystems of a country are involved and related is presented as a way to approach human development. The demographic subsystem is a side-by-side, single-gender, age-structured population dynamic model. The well-being subsystem states the dynamics of the United Nations Hybrid Human Development Index. The model has been validated in the case of Spain and Belgium. Some simulations have been performed with the model for the case of Spain in the 2009-2020 period to determine strategies and scenarios that could increase the life expectancy at birth per gender. Copyright © 2014 Taylor & Francis Group, LLC.
Simulation models in eGovernment using system dynamics: A literature survey
2016
System Dynamics (SD) is a method to build simulation models using computers, to study the behaviour of systems, and apply what-if scenarios aiming at achieving optimal policy design. To have an overview of the current state-of-the-art of SD use in the eGovernment field; we have surveyed related literature. Our main goal is to uncover the possibilities for future research by clarifying the shortages. The identified literature is not very large. In most of the literature, SD models use was limited to SD practitioners. We discovered low usage of Group Model Building and workshops despite their usefulness in involving non-SD practitioners in the model building process. Additionally, there is a …
The Rise and Fall of Humanitarian Citizen Initiatives: A Simulation-Based Approach
2020
Citizen Initiatives for Global Solidarity (CIGS) are small, ad hoc, volunteer organizations that arise in certain humanitarian and development contexts. They operate outside of traditional aid structures and may or may not cooperate with traditional government and nongovernmental organizations. Using agent-based modeling, we derive narrative-based, qualitative scenarios from simulation data to extend the theoretical discussions of CIGS as a phenomenon. The scenarios allow further discussion of the role that CIGS may play as development and humanitarian response actors outside of the traditional context-specific descriptions of CIGS that permeate the development literature. We find that scen…
Comparison of analytical methods and AI tools for material characterisation in hot forming
2002
Abstract Hot forming processes probably represent the most ancient of forming operations and what is more they are still today commonly used in modern mechanical industry in order to obtain sound parts, achieving large deformations with a limited required power. Hot metal forming operations are characterised by a large number of physical and thermal phenomena which have to be taken into account in order to model and design the processes themselves. Actually several thermally activated phenomena occur during the forming processes such as recovery, recrystallisation, grain growth, precipitation, allotropic transformations, etc. In this paper the comparison between an analytical method based o…
Fusion of visual tools in virtual spaces
1996
Virtual space environment may be improved by combining it with graphical and visual tools. This paper analyses an integrated system able to merge fusion techniques, icons tools and a virtual space environment. A virtual space is characterised by a set of dynamic visual icons and by a heterogeneous virtual reality environment. Their integration is supported by virtual icon grammar (VIG) working on dynamic icons and virtual world. VIG allows to test the actions made by dynamic icons on the activated Virtual World metaphors at a time “t”, and a range of different transactions that place between user and VW(visual query, view and browse of under-world,...), moreover, user can define, modify and…
Grip Force Adjustments Reflect Prediction of Dynamic Consequences in Varying Gravitoinertial Fields
2018
International audience; Humans have a remarkable ability to adjust the way they manipulate tools through a genuine regulation of grip force according to the task. However, rapid changes in the dynamical context may challenge this skill, as shown in many experimental approaches. Most experiments adopt perturbation paradigms that affect only one sensory modality. We hypothesize that very fast adaptation can occur if coherent information from multiple sensory modalities is provided to the central nervous system. Here, we test whether participants can switch between different and never experienced dynamical environments induced by centrifugation of the body. Seven participants lifted an object …
Analyzing Protein-Protein Spatial-Temporal Dependencies from Image Sequences Using Fuzzy Temporal Random Sets
2008
Total Internal Reflection Fluorescence Microscopy (TIRFM) allows us to image fluorescenttagged proteins near the plasma membrane of living cells with high spatial-temporal resolution. Using TIRFM imaging of GFP-tagged clathrin endocytic proteins, areas of fluorescence are observed as overlapping spots of different sizes and durations. Standard procedures to measure protein-protein colocalization of dual labeled samples threshold the original graylevel images to segment areas covered by different proteins. This binary logic is not appropriate as it leaves a free tuning parameter which can influence the conclusions. Moreover, these procedures rely on simple statistical analysis based on corre…