Tunis University

About: Tunis University is a education organization based out in Tunis, Tunisia. It is known for research contribution in the topics: Population & Thin film. The organization has 11745 authors who have published 15400 publications receiving 154900 citations. The organization is also known as: University of Tunis & UT.

Multiagent Framework for Smart Grids Recovery

Abstract: Failure propagation in smart grids (SGs) complicates and prolongs the recovery time as the faults to be resolved increase. This paper presents the design and implementation of a framework for SGs modeling, simulation, and recovery. The proposed approach is based on a multiagent system composed of static and mobile agents to ensure local and remote resolutions. The efficiency and completeness of the power system recovery protocol are proved as all the existing solutions are analyzed. The use of fault classification and a performing communication process as well as the deployment of local distributed databases updated at run-time ensure the effectiveness of the proposed fault recovery strategy. An experimental study confirms and validates the expected results.

The contribution of HLA class I and II alleles and haplotypes to the investigation of the evolutionary history of Tunisians.

Abstract: The frequencies of HLA class I and class II alleles and haplotypes of 104 healthy unrelated Tunisians were analyzed by high-resolution PCR-reverse dot blot hybridization, and was compared with other Mediterranean and Sub-Saharan Africans using genetic distances measurements, Neighbor-joining dendrograms, correspondence, and extended haplotypes analysis. The most frequent HLA class I A alleles were A*02, A*24, and A*30, while the most frequent B alleles were B*44, followed by B*50, B*51, and B*07. Among HLA class II DRB alleles analyzed, the most frequent were DRB1*0301, DRB1*0701, DRB1*1501, followed by DRB1*1303 and DRB1*0102; for DQB1, they were DQB1*0301 and DQB1*0201. Three-locus haplotype analysis revealed that A*03-B*07-DRB1*1503 and A*02-B*44-DRB1*0402 were the most common HLA class I and II haplotypes in this population. Compared with other communities, our result indicate that Tunisians are very related to North Africans and Western Europeans, particularly Iberians, and that Tunisians, Algerians, and Moroccans are close to Berbers suggesting little genetic contribution of Arabs who populated the area in 7th to 8th century AD. The similarities and differences between Tunisians and neighboring and related communities in HLA genotype distribution provide basic information for further studies of the MHC heterogeneity among Mediterranean and North African countries, and as reference for further anthropological studies.

Simultaneous Actuator and Sensor Faults Reconstruction Based on Robust Sliding Mode Observer for a Class of Nonlinear Systems

Abstract: This paper proposes a new robust fault reconstruction and estimation design for a class of nonlinear system described by the Takagi-Sugeno model with unmeasurable premise variables subject to faults affecting actuators, sensor faults, and unknown disturbances. The augmented Takagi-Sugeno system is introduced with a new fault vector which has two origins: the first one represents actuator faults, the second one denotes faults affecting sensors. The main contribution is focused primarily to conceive a sliding mode observer with two discontinuous terms designed to compensate for fault behavior and disturbance variation from the system states estimation. In the formalism of linear matrix inequalities, we derive sufficient conditions to guarantee the state estimation error stability and to obtain the observer gains. Meanwhile, additional effort is made to achieve simultaneous faults and disturbance reconstruction. Simulation results are given to illustrate the proposed approach performances.