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1.
ISA Trans ; 142: 626-634, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37586932

ABSTRACT

In this paper, a non-quadratic Lyapunov function is employed to reduce conservatism in a nonlinear observer designed for a class of continuous-time Takagi-Sugeno fuzzy systems with unmeasurable premise variables. This structure presents greater challenges compared to systems with measured variables. To overcome this issue, we utilize the mean value theorem and the sector nonlinearity transformation to convert the nonlinear error dynamics into a linear parameter-varying system. Moreover, we introduce the line integral Lyapunov function, which based on the integral of the membership functions, in order to ensure the global stability of the fuzzy systems under consideration. The use of this function offers several notable advantages over conventional quadratic forms, including a reduction in conservatism. Additionally, this type of functions constructed in a manner that eliminates the need for generating time derivatives of the membership functions, thereby simplifying calculations and analysis in comparison to other nonquadratic functions. Furthermore, it also enables capturing the system's behavior along a trajectory. The stability conditions are more relaxed and expressed as linear matrix inequalities, which can be solved using a linear programming approach through specialized software tools. To validate the effectiveness of the proposed methodology, we conducted a hardware-in-the-loop test using a flexible joint robot. The obtained results clearly underscore the success of the proposed approach.

2.
ISA Trans ; 133: 485-494, 2023 Feb.
Article in English | MEDLINE | ID: mdl-35933169

ABSTRACT

In this paper, we design a proportional integral observe for a nonlinear synchronous reluctance motor described by a Takagi-Sugeno multi-model. In this design, both states and unknown inputs are estimated simultaneously. First, the mathematical nonlinear model of the synchronous reluctance motor is established, then it transformed into a Takagi-Sugeno exact form by a simple polytopic transformation. In The second step, the proposed observer is designed to the obtained fuzzy system. Convergence conditions are expressed under a linear matrix inequality formulation using the second Lyapunov theorem, which guarantee a bounded error. Observer gains are obtained by solving a sum of constraints. For validation purposes, a hardware-in-the-loop implementation were carried out leading to results that clearly demonstrate the performance and effectiveness of the proposed technique.


Subject(s)
Algorithms , Fuzzy Logic , Computer Simulation , Nonlinear Dynamics , Models, Theoretical
3.
Case Rep Infect Dis ; 2021: 8816104, 2021.
Article in English | MEDLINE | ID: mdl-33747581

ABSTRACT

In this case report, we describe an unusual pathogen F. nucleatum-induced empyema, followed by the development of Guillain-Barré syndrome (GBS). Although many pathogens have been associated with GBS, this may be one of the few in the literature to describe an association with F. nucleatum infection.

4.
Bull Cancer ; 97(4): 461-8, 2010 Apr.
Article in French | MEDLINE | ID: mdl-20385518

ABSTRACT

The impact cancer occurrence is variable according to the sociocultural issue, specific to each context and each area. In order to determine the psychosocial profile of Moroccan patients that have developed cancers, four studies were performed at the National institute of oncology (INO) in Rabat. These studies were prospective, included between 125 and 1,600 patients and were based on questionnaires developed by a medical oncologist, a psychologist and a sociologist. These studies were focused on the psychosocial characteristics of the Moroccan cancer occurrence on patients, the impact of cancer on the religious practice as well as the impact of cancer and its treatments on patients' sexuality. In this article, we will develop the particular characteristics of moroccan patients that were specific to their sociocultural context.


Subject(s)
Cultural Characteristics , Neoplasms/psychology , Religion and Psychology , Sexuality/psychology , Socioeconomic Factors , Educational Status , Female , Humans , Male , Marital Status , Morocco , Neoplasms/ethnology , Prospective Studies , Sex Factors
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