Matei Dobrescu

Embedded Wireless Homecare Monitoring System

In this paper is described an embedded system for healthcare applications, actually a monitoring device for patients requiring continuous tele-monitoring treatments. The hardware architecture of the system, based on wireless communication, is discussed and implementation details are presented. We will also be presenting experimental results proving the usefulness of embedded homecare systems in providing patients with their health status monitoring.

Advanced Control of a Steam Generator

Economic feasibility of a nuclear power plant requires smooth and uninterrupted plant operation in the face of varying electrical power demand. The feed-water system in a nuclear power plant is a major contributor to plant unavailability. The investigations about operation experiences of a power plant show that one of frequent causes of shutdowns is by violation of safety limits on the water level and is common at low operating power where the plant exhibits strong non-minimum phase characteristics. This paper presents a framework for addressing this problem based on a method of advanced control based on fuzzy model predictive control. Furthermore, fuzzy model based fault detection methods are elaborated envisaging fault tolerant control. Results from validation of the advanced control system are presented. A new concept of modular advanced control system designed for a seamless and gradual integration into the existing distributed control system is proposed

Using internet traffic self-similarity for detection of network anomalies

The goal of this paper is to prove by simulations in an virtual environment the potential of fractal analysis techniques in evaluation of network characteristics, especially in detection of anomalies. In this aim there are proposed several original research results: an Internet model based on scale free network graphs, a method to reveal self-similarities in generated traffic, a method to compare the behavior of two sub-networks and a powerful experimental test-bed which allows parallel processing running pdns (parallel/distributed network simulator) package on different sub-networks having scale free topology.

Convergence of communication with computing for a remote oriented mobile minirobot

Abstract This paper describe a didactical platform for the study of the performances of a control system for mobile robots, composed from a workstation that ensure the data processing and a mobile module (minirobot) with autonomy of displacement. Successive are presented the platform characteristics and the solution for the coordination of local and remote communication and control system. The last section discusses interface problem (the low-level interface, the current middleware concept and the communication protocol) in the framework of a particular scenario where the platform would autonomously start communication in case of emergency. Conclusions and future work are finally presented.

Using texture and fractal analysis for classification of cell nuclei from light scattering spectroscopic images

The paper presents an original experimental optical LSS system which allows backscattering Mie diffusion spectra determination for biological samples. With the aim of evaluating viral infection effects, a software package performs fractal analysis of the spectra and texture analysis of the associated microscopic images. Finally a method for the classification of cell nuclei and the discrimination between virus infected and non-infected biological samples using a combined vector of the computed fractal and texture features is proposed.

Dependable Model for Enzyme Kinetics using Petri Networks

In this paper we propose a dependable model for single substrate enzyme kinetics based on the differential Petri network formalism. Metabolic signaling pathways contain biochemical reactions in which substrates are catalyzed enzymatic and turn them into active biochemical products. The enzyme reactions are described quantitatively through ordinary differential equations (ODEs) in the proposed Petri network model. The specificity of the biochemical reactions are captured in the proposed Petri network model. The simulation study shows qualitative validation of the dependability of the proposed Petri network model with experimental results for enzyme kinetics.

Differential Equations Systems versus Scale Free Networks in Sepsis Modeling

The paper proposes a comparison between models that relieves the characteristics of the patient evolution in sepsis as the result of correct or corrupted information transfer as the cell level. Specifically, two different models for the cellular interactions are compared - one based on a three variables system of differential equations, the other on a cellular interaction scale free network. The advantages and limits of each model in understanding the structure of cellular signaling networks involved in sepsis phenomena are finally discussed

Optimized Location Discovery Algorithm for Cooperative Activities of a Robot Team

This paper presents a novel location discovery algorithm used in collaborative work of a team of mobile mini-robots, which are connected as nodes of an inter-robot communication network. The location discovery scheme is a bio-inspired solution for collective decision making based on Outside of Transmission Range information from some reference nodes. The results obtained by simulation show that the proposed scheme can locate more nodes than the basic location discovery scheme by multi-lateration.

A Flows Consistency Model for Message Ordering in Collaborative Distributed Systems

Abstract The major contribution presented in this paper is an algorithm, which exploits the “flow concept” and selection policy to assure the delivery of strong operations with minimum delay for CSCW (Computer Supported Collaborative Work). The distributed algorithm guarantees the delivery of strong operation messages to the application in the same global order. Timestamps are used to enforce global ordering on the strong operations. The execution of any strong operation is postponed until the timestamp of that operation is smaller than all the estimated timestamp counters of the system. Then we define the flows concept that ensures a causal dependency relation among messages in order to preserve the context in which a message is sent. We prove that the flows concept and the global ordering algorithm together capture the requirements of the “flows consistency” model and we present execution examples that show how inconsistencies can appear if the system does not ensure causal synchronization. Finally, we demonstrate that the implementation of our message based distributed system assures causal consistency.

Fractal analysis of internet traffic using a parallel processing network simulator

The goal of this paper is to prove by simulations in an virtual environment the potential of fractal analysis techniques in evaluation of network characteristics putting together two new research results: an Internet model based on scale free network graphs where inference based on self similarity and fractal behavior can be applied and a powerful experimental test-bed which allows parallel processing running pdns (parallel/distributed network simulator) package simultaneously on different sub-networks having scale free topology.