1,720,959 research outputs found
Observers and State Reconstructions for Linear Neutral Time-Delay Systems
No full textThe problem of state reconstruction is discussed for linear neutral systems with a finite number of commensurable point delays. Using as models systems with coefficients in a ring and following a geometric point of view, feasible and constructive procedures are proposed for the design of observers of increasing complexity. Conditions are given to characterize neutral systems with delays for which linear observers exist not depending on the derivatives of the state. Some examples illustrating the results are worked out in details
Computational Algebra techniques for linear dynamical systems over rings: State Estimations Problems
No full text
Computational algebra techniques for linear dynamical systems over rings: State estimations problems
No full textLinear delay differential systems can be modeled as systems with coefficients in a suitable ring, so that several design problems can be solved using a geometric approach. To practically compute the solutions obtained for systems over a ring, Computational Algebra techniques must be used. The freely available software CoCoA is an efficient tool and easy to effectively implement the needed algorithms. The paper describes in details how the algorithms contained in the package "control.cpkg" can be used to practically solve State Estimations Problems for delay differential systems
Efficient algorithms for geometric control of systemsover rings
No full textThe Computational Algebra techniques described in this paper are a tool efficient and easy to implement using the freely available
software CoCoA. They open the way to an effective use of the geometric approach in dealing with dynamical systems over rings. Systems
with coefficients in a ring can be used to model several interesting classes of dynamical systems such as parameter dependent systems or
delay differential systems. The paper describes in details how the algorithms contained in the package “control.cpkg” can be used to
practically solve Decoupling Problems for delay differential systems
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
