Search results for " Modeling"
showing 10 items of 2411 documents
The Asynchronous Leontief Model
1992
International audience; The traditional dynamic Leontief model is synchronous: every vertex acts simultaneously. A model with delays of action has been proposed, but it still remains synchronous. In this paper we propose an asynchronous version of the model that allows realistic computations. We fiurnish an algorithm and a program.
High-fidelity analysis of multilayered shells with cut-outs via the discontinuous Galerkin method
2021
Abstract A novel numerical method for the analysis of multilayered shells with cut-outs is presented. In the proposed approach, the shell geometry is represented via either analytical functions or NURBS parametrizations , while generally-shaped cut-outs are defined implicitly within the shell modelling domain via a level set function . The multilayered shell problem is addressed via the Equivalent-Single-Layer approach whereby high-order polynomial functions are employed to approximate the covariant components of the displacement field throughout the shell thickness. The shell governing equations are then derived from the Principle of Virtual Displacements of three-dimensional elasticity an…
Los fenómenos disociativos: una revisión conceptual
2003
En el presente trabajo se lleva a cabo una revisión del concepto de disociación y de los fenómenos asociados, haciendo un recorrido desde las posturas clásicas, como la de Janet, hasta los planteamientos que actualmente se centran en el estudio de los fenómenos disociativos. Se aborda, además el planteamiento acerca de la existencia de un continuo de experiencias disociativas, o modelo dimensional, que actualmente se formula conjugado con un modelo tipológico, y se hace una breve revisión de los estudios que se han centrado en las relaciones entre la variable disociación y ciertas variables que tradicionalmente han sido asociadas a este concepto, como la hipnotizabilidad o la represión. Fin…
Predicting physical distancing over time during COVID-19: testing an integrated model.
2021
Objective: We applied an integrated social cognition model to predict physical distancing behavior, a key COVID-19 preventive behavior, over a four-month period. Design: A three-wave longitudinal survey design. Methods: Australian and US residents (N = 601) completed self-report measures of social cognition constructs (attitude, subjective norm, moral norm, perceived behavioral control [PBC]), intention, habit, and physical distancing behavior on an initial occasion (T1) and on two further occasions one week (T2) and four months (T3) later. Results: A structural equation model revealed that subjective norm, moral norm, and PBC, were consistent predictors of physical distancing intention on …
An empirically grounded agent based model for modeling directs, conflict detection and resolution operations in air traffic management
2017
We present an agent based model of the Air Traffic Management socio-technical complex system that aims at modeling the interactions between aircrafts and air traffic controllers at a tactical level. The core of the model is given by the conflict detection and resolution module and by the directs module. Directs are flight shortcuts that are given by air controllers to speed up the passage of an aircraft within a certain airspace and therefore to facilitate airline operations. Conflicts resolution between flight trajectories can arise during the en-route phase of each flight due to both not detailed flight trajectory planning or unforeseen events that perturb the planned flight plan. Our mod…
Decoupled solution of radial and weakly meshed distribution networks through a backward method
2008
A methodology for the analysis of radial or weakly meshed distribution systems supplying voltage dependent loads is developed. The solution process is iterative and, at each step, the loads are simulated by means of impedances. The network is divided into two sub-networks which must be solved separately and sequentially; in the first, named RP-net, only the lines resistances and the loads shunt equivalent resistances are considered; in the second, named XQ-net, only the lines reactances and the shunt equivalent reactances are taken into account. After a brief presentation of the b/f method, which is currently the most commonly used technique to solve distribution networks, the proposed meth…
Querying Dynamic and Context-Sensitive Metadata in Semantic Web
2005
RDF (core Semantic Web standard) is not originally appropriate for context representation, because of its initial focus on the ordinary Web resources, such as web pages, files, databases, services, etc., which structure and content are more or less stable. However, on the other hand, emerging industrial applications consider e.g. machines, processes, personnel, services for condition monitoring, remote diagnostics and maintenance, etc. to be specific classes of Web resources and thus a subject for semantic annotation. Such resources are naturally dynamic, not only from the point of view of changing values for some attributes (state of resource), but also from the point of view of changing “…
Models of Event Driven Systems
2016
This paper provides the business process modeling approach based on usage of Domain Specific Languages (DSL). The proposed approach allows us to create executable information systems’ models and extends the concept of Event Driven Architecture (EDA) with the business process execution description. It lets us apply principles of the Model Driven Development (MDD) in order to create the information system which complies with the model. The proposed approach provides a set of advantages in information systems development, use and maintenance: bridges the gap between business and IT, an exact specification, which is easily to implement into information system, up-to-date documentation etc. The …
Metamodel specialization for graphical modeling language support
2016
Most of current modeling languages are based on graphical diagrams. The concrete graphical syntax of these languages typically is defined informally -- by text and diagram examples. Only recently, starting from UML 2.5, a formalism is offered for defining the graphical syntax of UML. This formalism is based on Diagram Definition standard by OMG, where the main emphasis is on enabling diagram interchange between different tools implementing the given language. While this is crucial for standardized languages such as UML, this aspect is not so important for domain specific languages. In this paper an approach is offered for simple direct definition of concrete graphical syntax by means of met…
Concrete syntax-based find for graphical DSLs
2020
There are services available in the most software tools we have got used to like, copy, paste, cut, find, and replace. However, the state of the art is not so good with tools of graphical languages. Even many commercial modelling tools have limited support of the find feature. We propose to add find as a service of graphical DSL tool development frameworks. This way find is available in any DSL built using the DSL tool development framework. The concrete syntax-based find has been implemented as a service of the DSL tool development framework ajoo. Two graph-based languages: UML Activity diagrams and Deterministic Finite Automata (DFA) transition diagrams are used to demonstrate usage of th…