Search results for "granularity"
showing 10 items of 40 documents
MARL-Ped+Hitmap: Towards Improving Agent-Based Simulations with Distributed Arrays
2016
Multi-agent systems allow the modelling of complex, heterogeneous, and distributed systems in a realistic way. MARL-Ped is a multi-agent system tool, based on the MPI standard, for the simulation of different scenarios of pedestrians who autonomously learn the best behavior by Reinforcement Learning. MARL-Ped uses one MPI process for each agent by design, with a fixed fine-grain granularity. This requirement limits the performance of the simulations for a restricted number of processors that is lesser than the number of agents. On the other hand, Hitmap is a library to ease the programming of parallel applications based on distributed arrays. It includes abstractions for the automatic parti…
Dynamic coarse-graining fills the gap between atomistic simulations and experimental investigations of mechanical unfolding
2017
We present a dynamic coarse-graining technique that allows to simulate the mechanical unfolding of biomolecules or molecular complexes on experimentally relevant time scales. It is based on Markov state models (MSM), which we construct from molecular dynamics simulations using the pulling coordinate as an order parameter. We obtain a sequence of MSMs as a function of the discretized pulling coordinate, and the pulling process is modeled by switching among the MSMs according to the protocol applied to unfold the complex. This way we cover seven orders of magnitude in pulling speed. In the region of rapid pulling we additionally perform steered molecular dynamics simulations and find excellen…
A generalized Newton iteration for computing the solution of the inverse Henderson problem
2020
We develop a generalized Newton scheme IHNC for the construction of effective pair potentials for systems of interacting point-like particles.The construction is made in such a way that the distribution of the particles matches a given radial distribution function. The IHNC iteration uses the hypernetted-chain integral equation for an approximate evaluation of the inverse of the Jacobian of the forward operator. In contrast to the full Newton method realized in the Inverse Monte Carlo (IMC) scheme, the IHNC algorithm requires only a single molecular dynamics computation of the radial distribution function per iteration step, and no further expensive cross-correlations. Numerical experiments…
Exploring quantum matter with ultracold atoms in optical lattices
2005
Seventy years after Einstein's prediction, the seminal achievement of Bose–Einstein condensation in dilute atomic gases in 1995 has provided us with a new form of quantum matter. Such quantum matter can be described as a single giant matter wave. By loading it into an artificial periodic potential formed by laser light—a so-called optical lattice—it has become possible to probe matter far beyond the wave-like description. In a review of a series of experiments with ultracold quantum gases in optical lattices, we show that the granularity of the matter wave field, caused by the discreteness of atoms, gives rise to effects going beyond the simple single matter wave description. Bose–Einstein …
Computer Simulations and Coarse-Grained Molecular Models Predicting the Equation of State of Polymer Solutions
2010
Monte Carlo and molecular dynamics simulations are, in principle, powerful tools for carrying out the basic task of statistical thermodynamics, namely the prediction of macroscopic properties of matter from suitable models of effective interactions between atoms and molecules. The state of the art of this approach is reviewed, with an emphasis on solutions of rather short polymer chains (such as alkanes) in various solvents. Several methods of constructing coarse-grained models of the simple bead–spring type will be mentioned, using input either from atomistic models (considering polybutadiene as an example) or from experiment. Also, the need to have corresponding coarse-grained models of t…
Narrative Tools for Games : Focalization, Granularity, and the Mode of Narration in Games
2015
This article looks at three narratological concepts—focalization, granularity, and the mode of narration—and explores how these concepts apply to games. It is shown how these concepts can be used as tools for creating meaning-effects, which are understood here as cognitive responses from the player. Focalization is shown to have a hybrid form in games. This article also explores the different types of narrators and granularities in games, and how these three concepts can be used to create meaning-effects. This is done by discussing examples from several games, for example, Assassin’s Creed III, Skyrim, Fallout: New Vegas, and Civilization.
Semantic interoperability between BIM and GIS – review of existing standards and depiction of a novel approach
2019
International audience; When it comes to Big Data ecosystems, main technical challenges pertain to defining links between data, information and knowledge, thus reaching interoperability. Interoperability issues are addressed in the context of data curation related tasks. Interoperability is a major prerequisite for achieving data automation, validation, thus fighting counter-productiveness (notably through data incentivisation). The demand for interoperable, reusable and open data is more and more present, thus pushing forward the research for innovation data curation approaches. This article gives a high level description of our approach for bridging the interoperability gap among GIS (Geo…
Assessing the particle size of a broadly dispersed powder by complementary techniques
1998
The experimental determination of reliable particle size distribution curves and statistical parameters of broad distributions is known to be a difficult task. This problem is addressed here in an attempt to characterize the granularity of three distinct batches of a pharmaceutical powder (fenofibrate from Fournier Laboratories). The methodology consists in comparing the results, expressed in terms of surface based mean diameter, as obtained by three complementary techniques, namely optical microscopy image analysis, laser light low angle diffraction and surface area measurement by krypton physisorption. These techniques are applied in parallel to the material of interest and to a certified…
Unidirectional Direct Load Control through Smart Plugs
2014
International audience; Balancing energy demand and production is be-coming a more and more challenging task for energy utilities also because of the larger penetration of renewable energies which are more difficult to predict and control. While the traditional solution is to dynamically adapt energy production to follow time-varying demand, a new trend is to drive demand itself. Most of the ongoing actions in this direction involve greedy energy consumers, like industrial plants, supermarkets or large buildings. Pervasive communication technologies may allow in the near future to push further the granularity of such approach, by having the energy utility interacting with residen-tial appli…
Simplified Model to Predict Runoff Generation Time for Well-Drained and Vegetated Soils
2016
The study of generation process of subsurface stormflow, typical of well-drained and high permeable soils, can be theoretically carried out by applying the continuity and the motion equations with the appropriate boundary conditions. However, difficulties and uncertainness on determining soil hydraulic properties and soil physics heterogeneities let this way not always feasible. In a different way, processes dynamic can be derived by the local scale through a coarse graining procedure, allowing to preserve medium motion character, while hydraulic fluctuation of the motion are lost. Following an approach as this, in this paper a simplified model to predict the runoff generation time, the so-…