Thiago Abreu

• Paris-Est Créteil University

Monitoring water quality in urban rivers is crucial for water resource management since point and non-point source pollution remain a major challenge. However, traditional water quality monitoring methods are costly and limited in frequency and spatial coverage. To optimize the monitoring, techniques such as modeling have been proposed. These metho...

Exposure to contaminated water during aquatic recreational activities can lead to gastrointestinal diseases. In order to decrease the exposure risk, the fecal indicator bacteria Escherichia coli is routinely monitored, which is time-consuming, labor-intensive, and costly. To assist the stakeholders in the daily management of bathing sites, models h...

In the context of large-scale Internet of Things (IoT), one of the main issues comes from the lack of an efficient routing protocol that could handle thousands of devices and provide low-power forwarding mechanism for huge amounts of data. Moreover, the routing protocols must cope with the device-to-device architecture, where nodes no longer need a...

The rise of Smart Communications in Network Technologies has led to the growth of intelligent communications domains embedded in complex systems for a wide variety of applications in the next generation of network and cloud computing technologies. Indeed, autonomous systems embedded in complex configurations and dynamic environments have developed...

This article shows an environment for performing data collection in the computational system that provides the response service to “HTTP” requests and makes interventions in the values of the available parameters in order to control the system automatically in closed loop. The parameters to be obtained as endogenous variables of the computational s...

Multi-hop wireless networks are often regarded as a promising means to extend the limited coverage area offered by WLANs. However, they are usually associated with poor and uncertain performance in terms of available bandwidth and packet losses, which clearly stands as a limitation to their use. In this paper, we consider the performance evaluation...

In this paper we revisit the definition of user impatience in ubiquitous networks, by proposing a new characterization that does not reduce impatience to a simple timeout, like most previous works do. Instead, we characterize impatience by decoupling the cause of it, i.e., the probability that a given user becomes impatient, and the consequence, i....

Le protocole IEEE 802.11, basé sur les principes CMSA/CA, est largement déployé dans les communications sans fil actuelles, principalement en raison de sa simplicité et sa mise en œuvre à faible coût. Une utilisation intéressante de ce protocole peut être trouvée dans les réseaux sans fil multi-sauts, où les communications entre les nœuds peuvent i...

In this paper, we follow up an existing modeling framework to analytically evaluate the performance of multi-hop flows along a wireless chain of four nodes. The proposed model accounts for a non-perfect physical layer, handles the hidden node problem, and is applicable under workload conditions ranging from flow(s) with low intensity to flow(s) cau...

IEEE 802.11 is implemented in many wireless networks, including multi-hop networks where communications between nodes are conveyed along a chain. We present a modeling framework to evaluate the performance of flows conveyed through such a chain. Our framework is based on a hierarchical modeling composed of two levels. The lower level is dedicated t...

A substitution network is a wireless solution whose purpose is to bring back connectivity or to provide additional bandwidth capacity to a network that just suffered a failure or a dramatic surge in its workload. We analyze the performance of the simplest possible multihop topology for a substitution network, i.e., the multihop chain subject to tra...

This article presents an experimental study about parametric identification techniques applied to the modeling of an Apache webserver. In order to simulate load variations at the server, an experimental arrangement was developed, which is composed of two personal computers, one used to run the Apache server and the other to generate workload by req...