On elimination of chaotic behavior in a non-ideal portal frame structural system, using both passive and active controls

In this paper, an application is considered of both active and passive controls, to suppression of chaotic behavior of a simple portal frame, under the excitation of an unbalanced DC motor, with limited power supply (non-ideal problem). The adopted active control strategy consists of two controls: the nonlinear (feedforward) in order to keep the controlled system in a desirable orbit, and the feedback control, which may be obtained by considering state-dependent Riccati equation control to bringing the system into the desired orbit using a magneto rheological (MR) damper. To control the electric current applied in control of the MR damper the Bouc-Wen mathematical model was used to the MR damper. The passive control was obtained by means of a nonlinear sub-structure with properties of nonlinear energy sink. Simulations showed the efficiency of both the passive control (energy pumping) and active control strategies in the suppression of the chaotic behavior. © The Author(s) 2012.

Non-conventional vortex configurations in a mesoscopic flat disk

The influence of superficial defects on the vortex configurations of a thin superconducting disk is investigated within the time dependent Ginzburg-Landau formalism. The free energy, magnetization, vorticity, and the Cooper pair density are calculated for both metastable and stable vortex configurations and different number of defects on its surface in the presence of an external magnetic field applied perpendicular to the disk area. We show that the competition between the confinement geometry and the geometric position of the defects leads to non-conventional vortex configurations which are not compatible with the symmetry of the sample geometry.

Perturbation of a nonautonomous problem in ℝn

In this paper, we prove a stability result about the asymptotic dynamics of a perturbed nonautonomous evolution equation in ℝn governed by a maximal monotone operator. Copyright © 2013 John Wiley & Sons, Ltd. Copyright © 2013 John Wiley & Sons, Ltd.

Multilayer perceptron neural networks training through charged system search and its Application for non-technical losses detection

The non-technical loss is not a problem with trivial solution or regional character and its minimization represents the guarantee of investments in product quality and maintenance of power systems, introduced by a competitive environment after the period of privatization in the national scene. In this paper, we show how to improve the training phase of a neural network-based classifier using a recently proposed meta-heuristic technique called Charged System Search, which is based on the interactions between electrically charged particles. The experiments were carried out in the context of non-technical loss in power distribution systems in a dataset obtained from a Brazilian electrical power company, and have demonstrated the robustness of the proposed technique against with several others nature-inspired optimization techniques for training neural networks. Thus, it is possible to improve some applications on Smart Grids. © 2013 IEEE.

Método de Wang-Landau para sequenciamento de aminoácidos em estrutura nativa de proteínas em modelos de rede

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Generalized integral transform solution for hydrodynamically developing non-Newtonian flows in circular tubes

ABSTRACT: The Generalized Integral Transform Technique (GITT) is applied to the solution of the momentum equations in a hydrodynamically developing laminar flow of a non-Newtonian power-law fluid inside a circular duct. A primitive variables formulation is adopted in order to avoid the singularity of the auxiliary eigenvalue problem in terms of Bessel functions at the centerline of the duct when the GITT approach is applied. Results for the velocity field and friction factor-Reynolds number product are computed for different power-law indices, which are tabulated and graphically presented as functions of the dimensionless coordinates. Critical comparisons with previous results in the literature are also performed, in order to validate the numerical codes developed in the present work and to demonstrate the consistency of the final results.

Treatment of geophysical data as a non-stationary process

ABSTRACT: The Kalman-Bucy method is here analized and applied to the solution of a specific filtering problem to increase the signal message/noise ratio. The method is a time domain treatment of a geophysical process classified as stochastic non-stationary. The derivation of the estimator is based on the relationship between the Kalman-Bucy and Wiener approaches for linear systems. In the present work we emphasize the criterion used, the model with apriori information, the algorithm, and the quality as related to the results. The examples are for the ideal well-log response, and the results indicate that this method can be used on a variety of geophysical data treatments, and its study clearly offers a proper insight into modeling and processing of geophysical problems.

Structural bases for a complete myotoxic mechanism: Crystal structures of two non-catalytic phospholipases A(2)-like from Bothrops brazili venom

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Production lot sizing and scheduling with non-triangular sequence-dependent setup times

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A Modified Branch and Bound Algorithm to Solve the Transmission Expansion Planning Problem

In this paper a novel Branch and Bound (B&B) algorithm to solve the transmission expansion planning which is a non-convex mixed integer nonlinear programming problem (MINLP) is presented. Based on defining the options of the separating variables and makes a search in breadth, we call this algorithm a B&BML algorithm. The proposed algorithm is implemented in AMPL and an open source Ipopt solver is used to solve the nonlinear programming (NLP) problems of all candidates in the B&B tree. Strategies have been developed to address the problem of non-linearity and non-convexity of the search region. The proposed algorithm is applied to the problem of long-term transmission expansion planning modeled as an MINLP problem. The proposed algorithm has carried out on five commonly used test systems such as Garver 6-Bus, IEEE 24-Bus, 46-Bus South Brazilian test systems, Bolivian 57-Bus, and Colombian 93-Bus. Results show that the proposed methodology not only can find the best known solution but it also yields a large reduction between 24% to 77.6% in the number of NLP problems regarding to the size of the systems.

Non-nutritive sucking associated with self-mutilating behavior

Although sucking activity has been considered an essential behavior of early childhood to satisfy nutritive and non-nutritive needs, digit and pacifier sucking are deleterious oral habits that may interfere with child development. Furthermore, this clinical picture may be compounded by other concerning habits, such as self-mutilating behavior. This article reports 4-year follow-up of a child in whom non-nutritive sucking was associated with an unusual self-mutilating behavior; namely, the child would pull out her own hair after wrapping it around her finger every time she sucked on the pacifier. This occurred specially at bedtime, while she was watching TV, or when she was somewhat anxious, and remitted and recurred throughout the follow-up period. In an attempt to address this behavior, pacifier use was discontinued and the child’s head was shaved. Ultimately, the case was only solved through combined efforts involving the child, her family, and health professionals. Based on the parents’ reports and clinical examination and follow-up findings, we emphasize the importance of investigating the origin of the problem and considering emotional aspects and its association with other habits in such cases.

A method for retrieving endodontic or atypical non-endodontic separated instruments from the root canal: a report of two cases

Aim: This clinical report presents a new method for retrieving separated instruments from the root canal with minimally invasive procedures. Background: The presence of separated instrument in root canal may interfere in the endodontic treatment prognosis. There are several recommended methods to retrieve separated instruments, but some are difficult in clinically practice. Case report: This study describes two cases of separated instrument removal from the root canal using a stainless-steel prepared needle associated with a K-file. Case 1 presented a fractured gutta-percha condenser within the mandibular second premolar, it was separated during incorrect intracanal medication calcium hydroxide placement. Case 2 had a fractured sewing needle within the upper central incisor that the patient used to remove food debris from the root canal. After cervical preparation, the fractured instruments were fitted inside a prepared needle and then an endodontic instrument (#25 K-file) was adapted with clockwise turning motion between the needle inner wall and the fragment. Conclusion: The endodontic or atypical nonendodontic separated instrument may be easily pull on of the root canal using a single and low cost device. Clinical significance: The methods for retrieving separated instruments from root canal are difficult and destructive procedures. The present case describes a simple method to solve this problem.

Interior-exterior point method with global convergence strategy for solving the reactive optimal power flow problem

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A coupling technique for non-matching finite element meshes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Strategies and Precise Vocabulary Knowledge: Exploring the Relationships Among Mathematics Vocabulary, Problem Solving, and Confidence

In this action research study I focused on my eighth grade pre-algebra students’ abilities to attack problems with enthusiasm and self confidence whether they completely understand the concepts or not. I wanted to teach them specific strategies and introduce and use precise vocabulary as a part of the problem solving process in hopes that I would see students’ confidence improve as they worked with mathematics. I used non-routine problems and concept-related open-ended problems to teach and model problem solving strategies. I introduced and practiced communication with specific and precise vocabulary with the goal of increasing student confidence and lowering student anxiety when they were faced with mathematics problem solving. I discovered that although students were working more willingly on problem solving and more inclined to attempt word problems using the strategies introduced in class, they were still reluctant to use specific vocabulary as they communicated to solve problems. As a result of this research, my style of teaching problem solving will evolve so that I focus more specifically on strategies and use precise vocabulary. I will spend more time introducing strategies and necessary vocabulary at the beginning of the year and continue to focus on strategies and process in order to lower my students’ anxiety and thus increase their self confidence when it comes to doing mathematics, especially problem solving.