Search results for "Online"

Tetraethynylethene molecular scaffolding: Nonlinear optical, redox, and amphiphilic properties of donor functionalized polytriacetylene and expanded …

1997

Star-product approach to quantum field theory: The free scalar field

1990

The star-quantization of the free scalar field is developed by introducing an integral representation of the normal star-product. A formal connection between the Feynman path integral in the holomorphic representation and the star-exponential is established for the interacting scalar fields.

SCALING LAWS FOR THE LIFETIMES OF GOVERNMENTS IN THE SZNAJD DEMOCRACY

2005

We investigate the lifetimes of governments in the original and a randomized one-dimensional Sznajd model. We find various scaling laws for the lifetime of the democracy and for the reigning time of governments in this model, depending on the system size N.

An adaptive multimeme algorithm for designing HIV multidrug therapies.

2007

This paper proposes a period representation for modeling the multidrug HIV therapies and an Adaptive Multimeme Algorithm (AMmA) for designing the optimal therapy. The period representation offers benefits in terms of flexibility and reduction in dimensionality compared to the binary representation. The AMmA is a memetic algorithm which employs a list of three local searchers adaptively activated by an evolutionary framework. These local searchers, having different features according to the exploration logic and the pivot rule, have the role of exploring the decision space from different and complementary perspectives and, thus, assisting the standard evolutionary operators in the optimizati…

Adaptive control of a class of strict-feedback time-varying nonlinear systems with unknown control coefficients

2018

Abstract In this paper, robust adaptive control of a class of strict-feedback nonlinear systems with unknown control directions is investigated. A novel Nussbaum-type function is developed and a key theorem is drawn which involves quantifying the addition of multiple Nussbaum functions with different control directions in a single inequality. Global stability of the closed-loop system and asymptotic stabilization of system output are proved. A simulation example is given to illustrate the effectiveness of the proposed control scheme.

Experimental demonstration of an ultrafast all-optical bit-error indicating scheme

2010

International audience; We experimentally demonstrate an all-optical bit error monitoring scheme based on the self-phase modulation occurring during the propagation in a highly nonlinear fiber followed by an optical bandpass filter. Numerical simulations are confirmed by experimental observations performed at a repetition rate of 40 Gb/s.

Adaptive backstepping based consensus tracking of uncertain nonlinear systems with event-triggered communication

2021

Abstract This paper investigates the consensus tracking problem for a class of uncertain high-order nonlinear systems with parametric uncertainties and event-triggered communication. Under a directed communication condition, a totally distributed adaptive backstepping based control scheme is presented. Specifically, a decentralized triggering condition is adopted in this paper such that continuous monitoring of neighboring states, as required in some existing results, can be avoided. Besides, to handle the non-differentiability problem of virtual controllers, which arises from the utilization of neighboring states collected only at the triggering instants, the virtual controllers in each re…

The PCHIP subdivision scheme

2016

In this paper we propose and analyze a nonlinear subdivision scheme based on the monotononicity-preserving third order Hermite-type interpolatory technique implemented in the PCHIP package in Matlab. We prove the convergence and the stability of the PCHIP nonlinear subdivision process by employing a novel technique based on the study of the generalized Jacobian of the first difference scheme. MTM2011-22741

Approximation-based adaptive tracking control of stochastic nonlinear systems with a general form

2014

In this paper, an approximation-based adaptive tracking control scheme is proposed for a class of stochastic nonlinear systems with a more general structure. Fuzzy logical systems are used to approximate unknown nonlinearities in the controller design procedure and the backstepping technique is utilized to construct a state-feedback adaptive controller. The proposed controller can guarantee that all the signals in the closed-loop system are fourth-moment semi-globally uniformly ultimately bounded and the tracking error eventually converges to a small neighborhood around the origin. Simulation results are used to show the effectiveness of the proposed control scheme.

A Performance-Based Test for Assessing Students’ Online Inquiry Competences in Schools

2018

In this paper, we introduce a performance-based test for measuring adolescents’ competences in online inquiry. The test covers four competence dimensions: (1) searching and selecting relevant sources, (2) identifying the main ideas presented in the sources, (3) evaluating the credibility of the sources, and (4) synthesizing information across the sources. We implement a technological solution called NEURONE to carry out this routine. The scoring of the test data is demonstrated by presenting preliminary results of a case study. Finally, we discuss the strengths and limitations of the test.