Scaling properties and universality in a ratchet system

Critical exponents that describe a transition from unlimited to limited diffusion for a ratchet system are obtained analytically and numerically. The system is described by a two dimensional nonlinear mapping with three relevant control parameters. Two of them control the non-linearity while the third one controls the intensity of the dissipation. Chaotic attractors appear in the phase space due to the dissipation and considering large non-linearity are characterised by the use of Lyapunov exponents. The critical exponents are used to overlap different curves of average momentum (dynamical variable) onto a single plot confirming a scale invariance. The formalism used is general and the procedure can be extended to different systems.

A dialética singular-particular-universal: implicações do método materialista dialético para a psicologia

Considering that Cultural-Historical theory has been gaining importance within Brazilian Psychology in the last decades, this essay aims at contributing to understanding its ontological and epistemological foundations, introducing the concepts of singularity, particularity and universality of the dialectics that exists between them. The analysis looks to explore the implications to Psychology, both as a science and as a professional practice, of the lukacsian indication about the need to apprehend the connections between singularity, particularity and universality as a condition for understanding the essence of phenomena. In that sense, this analysis brings light to the individual/society dynamics unity affirmed by historical-dialectical materialism, which contributes to overcoming of the dichotomies usually established between the poles of this relationship.

A multiprojeção de ambientes virtuais gerados por motores de jogo: o histórico e o design de uma solução genérica aplicado no motor de jogo Unity

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Universality in bibliometrics

Many discussions have enlarged the literature in Bibliometrics since the Hirsch proposal, the so called h-index. Ranking papers according to their citations, this index quantifies a researcher only by its greatest possible number of papers that are cited at least h times. A closed formula for h-index distribution that can be applied for distinct databases is not yet known. In fact, to obtain such distribution, the knowledge of citation distribution of the authors and its specificities are required. Instead of dealing with researchers randomly chosen, here we address different groups based on distinct databases. The first group is composed of physicists and biologists, with data extracted from Institute of Scientific Information (IS!). The second group is composed of computer scientists, in which data were extracted from Google-Scholar system. In this paper, we obtain a general formula for the h-index probability density function (pdf) for groups of authors by using generalized exponentials in the context of escort probability. Our analysis includes the use of several statistical methods to estimate the necessary parameters. Also an exhaustive comparison among the possible candidate distributions are used to describe the way the citations are distributed among authors. The h-index pdf should be used to classify groups of researchers from a quantitative point of view, which is meaningfully interesting to eliminate obscure qualitative methods. (C) 2011 Elsevier B.V. All rights reserved.

On the implementation of good manufacturing practices in a small processing unity of mozzarella cheese in Brazil

This study reports the implementation of GMPs in a mozzarella cheese processing plant. The mozzarella cheese manufacturing unit is located in the Southwestern region of the state of Parana, Brazil, and processes 20,000 L of milk daily. The implementation of GMP took place with the creation of a multi-disciplinary team and it was carried out in four steps: diagnosis, report of the diagnosis and road map, corrective measures and follow-up of GMP implementation. The effectiveness of actions taken and GMP implementation was compared by the total percentages of non-conformities and conformities before and after implementation of GMR Microbiological indicators were also used to assess the implementation of GMP in the mozzarella cheese processing facility. Results showed that the average percentage of conformity after the implementation of GMP was significant increased to 66%, while before it was 32% (p < 0.05). The populations of aerobic microorganisms and total coliforms in equipment were significantly reduced (p < 0.05) after the implementation of GMP, as well as the populations of total coliforms in the hands of food handlers (p < 0.05). In conclusion, GMP implementation changed the overall organization of the cheese processing unity, as well as managers and food handlers' behavior and knowledge on the quality and safety of products manufactured. (C) 2011 Elsevier Ltd. All rights reserved.

UNIVERSALITY OF RANDOM GRAPHS

We prove that asymptotically (as n -> infinity) almost all graphs with n vertices and C(d)n(2-1/2d) log(1/d) n edges are universal with respect to the family of all graphs with maximum degree bounded by d. Moreover, we provide an efficient deterministic embedding algorithm for finding copies of bounded degree graphs in graphs satisfying certain pseudorandom properties. We also prove a counterpart result for random bipartite graphs, where the threshold number of edges is even smaller but the embedding is randomized.

Realizzazione di una visita interattiva del Museo Civico di Galeata (FC) tramite Maya e Unity 3d

Questa tesi è stata realizzata con l’obiettivo di fornire un metodo alternativo e innovativo per la divulgazione e l’apprendimento della storia, mediante la realizzazione di una visita virtuale al Museo Civico Mambrini di Galeata (FC), ottenuta facendo uso della Computer Grafica. La scelta del Museo Civico Mambrini di Galeata è stata dettata dalla possibilità di valorizzare il patrimonio storico-culturale di una vallata, quella del fiume Bidente, che dispone di una grande quantità di siti archeologici e edifici dalla grande importanza storica.

Estensione del game engine Unity per la generazione procedurale di ambienti per videogiochi

In questo elaborato viene descritto il lavoro svolto per sviluppare un generatore procedurale di ambienti per videogiochi, più propriamente definiti con il temine dungeon. Lo strumento creato viene integrato all'interno del game engine Unity ed è di carattere generale: può essere utilizzato per qualunque gioco che richieda una generazione procedurale di livelli.

Visita virtuale alla Rocca di Forlimpopoli mediante l'uso di Maya e Unity 3D

Il lavoro svolto in questa tesi mira alla creazione di un modello 3D della Rocca di Forlimpopoli mediante l'uso dei programmi Maya e Unity 3D. La combinazione di queste due tecnologie permette all'utente di utilizzare il prodotto finale per visitare virtualmente la rocca, muovendosi a proprio piacimento all'interno del modello del monumento, esplorandone anche le porzioni normalmente non accessibili al pubblico, o visitabili solo in determinate occasioni.

Optimal current control for sub-unity power factor correction

Switching mode power supplies (SMPS) are subject to low power factor and high harmonic distortions. Active power-factor correction (APFC) is a technique to improve the power factor and to reduce the harmonic distortion of SMPSs. However, this technique results in double frequency output voltage variation which can be reduced by using a large output capacitance. Using large capacitors increases the cost and size of the converter. Furthermore, the capacitors are subject to frequent failures mainly caused by evaporation of the electrolytic solution which reduce the converter reliability. This thesis presents an optimal control method for the input current of a boost converter to reduce the size of the output capacitor. The optimum current waveform as a function of weighing factor is found by using the Euler Lagrange equation. A set of simulations are performed to determine the ideal weighing which gives the lowest possible output voltage variation as the converter still meets the IEC-61000-3-2 class-A harmonics requirements with a power factor of 0.8 or higher. The proposed method is verified by the experimental work. A boost converter is designed and it is run for different power levels, 100 W, 200 W and 400 W. The desired output voltage ripple is 10 V peak to peak for the output voltage of 200 Vdc. This ripple value corresponds to a ± 2.5% output voltage ripple. The experimental and the simulation results are found to be quite matching. A significant reduction in capacitor size, as high as 50%, is accomplished by using the proposed method.