Search results for "Simulation."
showing 10 items of 4779 documents
Introducing the Concept of Hyperactivity in Multi Agent Systems
2013
International audience; Software Agents are no longer the simple communication gateways for devices to interconnect using one or more networks. With Multi Agent Systems contributing in a wide spectrum of intelligent systems, the Agents are in a more proactive role than just being responsible for passing messages between their respective base systems. Agent Relation Charts and the Hyperactive Transaction Model in general is one of the recent attempts of developing a multi-view design model for Multi Agent Systems. The model has made a clear distinction in the regular and intelligent activities of an agent. Based on these differences, the agents are classified into three main categories named…
D Sensor-Based Obstacle Detection Comparing Octrees and Point clouds Using CUDA
2012
This paper presents adaptable methods for achieving fast collision detection using the GPU and Nvidia CUDA together with Octrees. Earlier related work have focused on serial methods, while this paper presents a parallel solution which shows that there is a great increase in time if the number of operations is large. Two dierent models of the environment and the industrial robot are presented, the rst is Octrees at dierent resolutions, the second is a point cloud representation. The relative merits of the two dierent world model representations are shown. In particular, the experimental results show the potential of adapting the resolution of the robot and environment models to the task at h…
Channel Occupancy-Based Dynamic Spectrum Leasing in Multichannel CRNs: Strategies and Performance Evaluation
2016
Spectrum leasing has been proposed as an effective approach for enabling more flexible spectrum utilization in CRNs. In CRNs, a primary network (PN) which consists of multiple primary users (PUs) can lease part of the licensed spectrum to secondary users (SUs) in exchange for operational benefits. The focus of this study is to investigate how and to what extent the PN allows spectrum leasing in CRNs, considering the QoS requirements of the PN and the secondary network (SN). Correspondingly, we propose two dynamic spectrum leasing strategies, which can improve the QoS performance of SUs while ensuring sufficient remuneration for PUs. In order to dynamically adjust the portion of leased bandw…
Interference Estimation in IEEE 802.11 Networks
2010
This article describes a technique for distinguishing and quantifying medium access control (MAC) and physical layer (PHY) interference in error-prone 802.11 networks. This technique, is fully distributed, allowing each station to estimate interference individually. The estimator is based on an extended Kalman filter coupled to a mechanism for revealing abrupt changes in state. The network state is a vector of two components, representing PHY interference, expressed in terms of channel-error rate, and MAC interference. Two distinct state models are considered. When PHY interference can be assumed to be constant for all stations, network congestion is expressed by the number of competing ter…
An Integrated Framework for Meta Modeling
2006
Meta modeling is an essential means to systematize, formalize, standardize, integrate, analyze and compare models, techniques, methods and tools. Numerous fields, such as databases, software engineering, software architectures, semantic web, computer-aided tools and method engineering, have benefited from it. The importance of meta modeling is ever increasing along with the emergence of novel approaches, architectures, techniques and languages based on UML and MDA. This paper presents a framework to integrate and compare divergent conceptions of meta modeling in databases, software engineering, and information systems development. The framework is applied to analyze and compare conceptions …
Hybrid descriptive-inferential method for key feature selection in prostate cancer radiomics
2021
In healthcare industry 4.0, a big role is played by radiomics. Radiomics concerns the extraction and analysis of quantitative information not visible to the naked eye, even by expert operators, from biomedical images. Radiomics involves the management of digital images as data matrices, with the aim of extracting a number of morphological and predictive variables, named features, using automatic or semi-automatic methods. Multidisciplinary methods as machine learning and deep learning are fully involved in this field. However, the large number of features requires efficient and effective core methods for their selection, in order to avoid bias or misinterpretations problems. In this work, t…
A measurement-based trajectory model for drifted motions towards a target zone
2016
Trajectory models have numerous applications in the area of wiewlwss communications. The aim of this paper is to develop an empirical trajectory model for drifted motions. Recently, a highly flexible trajectory model based on the primitives of Brownian fields (TramBrown) was proposed by A. Borhani and M. Patzold. This paper provides an empirical proof for TramBrown using global positioning system (GPS) data collected from real life user traces drifting to a particular target point or a zone. The recorded location coordinates of the mobile user are processed to compute the total travelling length and the angle-of-motion (AOM) along the drifted trajectory. It is shown that the probability den…
The dynamics over the next few years of the Spanish mobile telecommunications market share: a mathematical modelling approach
2013
Taking into account available data from 2002 to 2009 about the market share percentages of the Spanish mobile telecommunications service providers, a dynamic diffusion model to study the evolution of the clients’ change between the different companies during the period 2010–2016 is proposed. The constructed model provides a tool for forecasting short-term trends about the customers’ preferences with respect to mobile network operators taking into account both, autonomous decisions due to direct marketing and advertising strategies, and also decisions adopted through interaction via social influence. The model can provide insights to companies for designing strategies in order to gain market…
Probabilistic models for the fatigue resistance of welded steel joints subjected to constant amplitude loading
2022
Abstract S-N curves found in various rules and regulations are the basic tool for the practicing engineer when carrying out life predictions for welded details in dynamically loaded structures. The present work is investigating the expected fatigue life and associated scatter for welded steel joints subjected to Constant Amplitude (CA) loading. The objective is to obtain more reliable life predictions based on advancements in the probabilistic model fitted to collected life data. A Random Fatigue Limit Model (RFLM) is proposed to obtain fatigue resistance curves at given probability levels of survival. As a distinction to more conventional statistical methods, the model is treating both the…
A Bayesian Learning Automata-Based Distributed Channel Selection Scheme for Cognitive Radio Networks
2014
We consider a scenario where multiple Secondary Users SUs operate within a Cognitive Radio Network CRN which involves a set of channels, where each channel is associated with a Primary User PU. We investigate two channel access strategies for SU transmissions. In the first strategy, the SUs will send a packet directly without operating Carrier Sensing Medium Access/Collision Avoidance CSMA/CA whenever a PU is absent in the selected channel. In the second strategy, the SUs implement CSMA/CA to further reduce the probability of collisions among co-channel SUs. For each strategy, the channel selection problem is formulated and demonstrated to be a so-called "Potential" game, and a Bayesian Lea…