Big Data Privacy Context: Literature Effects On Secure Informational Assets

This article's objective is the identification of research opportunities in the current big data privacy domain, evaluating literature effects on secure informational assets. Until now, no study has analyzed such relation. Its results can foster science, technologies and businesses. To achieve these objectives, a big data privacy Systematic Literature Review (SLR) is performed on the main scientific peer reviewed journals in Scopus database. Bibliometrics and text mining analysis complement the SLR. This study provides support to big data privacy researchers on: most and least researched themes, research novelty, most cited works and authors, themes evolution through time and many others. In addition, TOPSIS and VIKOR ranks were developed to evaluate literature effects versus informational assets indicators. Secure Internet Servers (SIS) was chosen as decision criteria. Results show that big data privacy literature is strongly focused on computational aspects. However, individuals, societies, organizations and governments face a technological change that has just started to be investigated, with growing concerns on law and regulation aspects. TOPSIS and VIKOR Ranks differed in several positions and the only consistent country between literature and SIS adoption is the United States. Countries in the lowest ranking positions represent future research opportunities.Comment: 21 pages, 9 figure

Instantons and Fluctuations in a Lagrangian Model of Turbulence

We perform a detailed analytical study of the Recent Fluid Deformation (RFD) model for the onset of Lagrangian intermittency, within the context of the Martin-Siggia-Rose-Janssen-de Dominicis (MSRJD) path integral formalism. The model is based, as a key point, upon local closures for the pressure Hessian and the viscous dissipation terms in the stochastic dynamical equations for the velocity gradient tensor. We carry out a power counting hierarchical classification of the several perturbative contributions associated to fluctuations around the instanton-evaluated MSRJD action, along the lines of the cumulant expansion. The most relevant Feynman diagrams are then integrated out into the renormalized effective action, for the computation of velocity gradient probability distribution functions (vgPDFs). While the subleading perturbative corrections do not affect the global shape of the vgPDFs in an appreciable qualitative way, it turns out that they have a significant role in the accurate description of their non-Gaussian cores.Comment: 32 pages, 9 figure

The Onset of Intermittency in Stochastic Burgers Hydrodynamics

We study the onset of intermittency in stochastic Burgers hydrodynamics, as characterized by the statistical behavior of negative velocity gradient fluctuations. The analysis is based on the response functional formalism, where specific velocity configurations - the viscous instantons - are assumed to play a dominant role in modeling the left tails of velocity gradient probability distribution functions. We find, as expected on general grounds, that the field theoretical approach becomes meaningful in practice only if the effects of fluctuations around instantons are taken into account. Working with a systematic cumulant expansion, it turns out that the integration of fluctuations yields, in leading perturbative order, to an effective description of the Burgers stochastic dynamics given by the renormalization of its associated heat kernel propagator and the external force-force correlation function.Comment: 10 pages, 6 figure

Markovian Description of Unbiased Polymer Translocation

We perform, with the help of cloud computing resources, extensive Langevin simulations which provide compelling evidence in favor of a general markovian framework for unbiased polymer translocation. Our statistical analysis consists of careful evaluations of (i) two-point correlation functions of the translocation coordinate and (ii) the empirical probabilities of complete polymer translocation (taken as a function of the initial number of monomers on a given side of the membrane). We find good agreement with predictions derived from the Markov chain approach recently addressed in the literature by the present authors.Comment: 11 pages, 4 figure

Free Energy Evaluation in Polymer Translocation via Jarzynski Equality

We perform, with the help of cloud computing resources, extensive Langevin simulations which provide free energy estimates for unbiased three dimensional polymer translocation. We employ the Jarzynski equality in its rigorous setting, to compute the variation of the free energy in single monomer translocation events. In our three-dimensional Langevin simulations, the excluded-volume and van der Waals interactions between beads (monomers and membrane atoms) are modeled through a repulsive Lennard-Jones (LJ) potential and consecutive monomers are subject to the Finite-Extension Nonlinear Elastic (FENE) potential. Analysing data for polymers with different lengths, the free energy profile is noted to have interesting finite size scaling properties.Comment: 14 pages, 5 figures, Accepted for publication in Physics Letters

Option Pricing from Wavelet-Filtered Financial Series

We perform wavelet decomposition of high frequency financial time series into large and small time scale components. Taking the FTSE100 index as a case study, and working with the Haar basis, it turns out that the small scale component defined by most ($\simeq$ 99.6%) of the wavelet coefficients can be neglected for the purpose of option premium evaluation. The relevance of the hugely compressed information provided by low-pass wavelet-filtering is related to the fact that the non-gaussian statistical structure of the original financial time series is essentially preserved for expiration times which are larger than just one trading day.Comment: 4 pages, 1 figur

Estudo bibliométrico no Portal Capes: termos e conceitos de educação em museu

Investigates the issue of visibility of scientific journals on the Portal Capes, due to the adoption of keywords in the valuation of an area of knowledge. It aims to reflect on the interference of terms adopted to access the scientific production and the strengthening of the area of knowledge, aiming at a more effective approximation between literature and its users. The study explores the identification of the scientific production focused on the theme "museum education", as a guide in the context of science dissemination (Portal Capes). It was observed that the terminology used for bibliographical productions presents the concepts and terms shared in related areas and of several disciplines, often with contradictory definitions, that do not certify the communication between peers. From this perception, the terms "museology", "interdisciplinary" and "non-formal education", are mainly based on Cerávolo, Japiassú and Trilla. By these references, the terms that were used in the methodological approach were selected, and were identified preferentially in the "Scopes" (section that presents the determined focus on the area of interest of the journals).The data were collected exclusively from Portal Capes, specifically in the area of human knowledge, subarea Education, and in the area of knowledge Applied Social Sciences, sub-area Museology. The research sought to identify in the 1,219 journals of the first subarea and in the 25 journals found in the second, the terminology that was relevant to divulge and access the subject matter. From the results obtained by the bibliometric analysis, which besides the data collection allows a reflection based on the context, it is concluded that "Education in museum" is a theme recognized by both subareas, but little identified by them. Although the term was detected in 9 of the total journals of the subarea Education, and has no occurrence in the subarea Museology, both have shown to be receptive to publish articles on the subject.Investiga a questão da visibilidade dos periódicos científicos no Portal Capes, em decorrência da adoção de palavras chave na valorização de uma área do conhecimento. Tem por objetivo, refletir sobre a adoção de termos como interferência no acesso da produção científica e no fortalecimento da área do conhecimento, visando uma aproximação mais eficaz entre a literatura e seus usuários. Neste estudo procurou-se explorar a identificação da produção voltada para a temática “educação em museu”, guia neste ambiente de divulgação da ciência. Observou-se que a terminologia empregada nas produções bibliográficas apresenta o emprego de conceitos e termos compartilhados em áreas afins e de diversas disciplinas, muitas vezes com definições contraditórias, que não certificam a comunicação entre os pares. Nesta percepção, são problematizados os termos “museologia” “interdisciplinaridade”, “educação não formal”, fundamentados principalmente em Cerávolo, Japiassú e Trilla. A partir desse embasamento, foram selecionados termos que utilizados na abordagem metodológica, visavam ser identificados preferencialmente nos “Escopos” (seção que apresenta as finalidades determinadas sobre a área de interesse dos periódicos). Aplicada exclusivamente no Portal Capes, especificamente na área do conhecimento Humanas, subárea Educação, e na área do conhecimento Ciências Sociais Aplicadas, subárea Museologia, a pesquisa buscou identificar, entre os 1.219 periódicos da primeira subárea e entre os 25 periódicos encontrados na segunda, a terminologia que se mostrou relevante para divulgar e acessar a temática contemplada. A partir dos resultados obtidos pela análise bibliométrica, que além do levantamento de dados possibilita uma reflexão balizada no contexto, conclui-se que “Educação em museu” é uma temática reconhecida por ambas as subáreas, mas pouco identificada por elas. Apesar do termo ter sido detectado em 9 do total de periódicos da subárea Educação, e não ter nenhuma ocorrência na subárea Museologia, as duas demonstraram estar receptíveis para publicar artigos sobre o assunto

Scaling of turbulent separating flows

AbstractThe present work investigates the scaling of the turbulent boundary layer in regions of adverse pressure gradient flow. For the first time, direct numerical simulation and experimental data are applied to the theory presented in Cruz and Silva Freire [Cruz, D. O. A., & Silva Freire, A. P. (1998). On single limits and the asymptotic behaviour of separating turbulent boundary layers. International Journal of Heat and Mass Transfer, 41, 2097–2111] to explain how the classical two-layered asymptotic structure reduces to a new structure consistent with the local solutions of Goldstein and of Stratford at a point of zero wall shear stress. The work discusses in detail the behaviour of an adaptable characteristic velocity (uR) that can be used in regions of attached as well as separated flows. In particular, uR is compared to velocity scales based on the local wall shear stress and on the pressure gradient at the wall. This is also made here for the first time. A generalized law of the wall is compared with the numerical and experimental data, showing good agreement. This law is shown to reduce to the classical logarithmic solution and to the solution of Stratford under the relevant limiting conditions

Obstacle avoidance strategy based on adaptive potential fields generated by an electronic stick

In our previous work, an obstacle avoidance algorithm, which used potential fields and a similar strategy to that adopted by a blind person to avoid obstacles whilst walking, was proposed. The problem analyzed consists of an AGV (Autonomous Guided Vehicle) which moves within an office environment with a known floor plan and uses an ”electronic stick” made up of infrared sensors to detect unknown obstacles in its path. Initially, a global potential navigation function, defined for each room in the floor plan, incorporates information about the dimensions of the room and the position of the door which the AGV must use to leave the room. Whilst the AGV moves, this global potential navigation function is properly modified to incorporate information about any newly detected obstacle. The main interesting aspect of the proposed approach is that the potential function adaptation involves very low computational burden allowing for the use of Ultra-fast AGVs. Other distinctive features of the algorithm are that it is free from local minima, the obstacles can have any shape, low cost sensors can be used to detect obstacles and an appropriate balance is achieved between the use of the global and the local approaches for collision avoidance. Our present work is a refinement of this strategy that allows for an automatic real time adaptation of the algorithm’s parameters. Now, the algorithm’s functioning requires only that the minimum distance at which the AGV can approach an obstacle (i.e. the closest it can get to any obstacle) is defined a priori. Aspects of the real implementation of the algorithm are also discussed

PM-PVM: a portable multithreaded PVM

PM-PVM is a portable implementation of PVM designed to work on SMP architectures supporting multithreading. PM-PVM portability is achieved through the implementation of the PVM functionality on top of a reduced set of parallel programming primitives. Within PM-PVM; PVM tasks are mapped onto threads and the message passing functions are implemented using shared memory. Three implementation appproaches of the PVM message passing functions have been adopted. In the first one, a single message copy in memory is shared by alI destination tasks. The second one replicates the message for every destination task but requires less synchronization. Finally, the third approach uses a combination of features from the two previous ones. Experimental results comparing the performance of PM-PVM and PVM applications running on a 4-processor Sparcstation 20 under Solaris 2.5 show that PM-PVM can produce execution times up to 54% smaller than PVM