Enhancing network transmission capacity by efficiently allocating node capability

A network s transmission capacity is the maximal rate of traffic inflow that the network can handle without causing congestion Here we study how to enhance this quantity by allocating resource to individual nodes while preserving the total amount of the resource available We propose a practical and effective scheme which redistributes node capability based on the local knowledge of node connectivity We show that our scheme enhances the transmission capacity of networks with heterogeneous structures by up to two orders of magnitude

SpikingLab: modelling agents controlled by Spiking Neural Networks in Netlogo

The scientific interest attracted by Spiking Neural Networks (SNN) has lead to the development of tools for the simulation and study of neuronal dynamics ranging from phenomenological models to the more sophisticated and biologically accurate Hodgkin-and-Huxley-based and multi-compartmental models. However, despite the multiple features offered by neural modelling tools, their integration with environments for the simulation of robots and agents can be challenging and time consuming. The implementation of artificial neural circuits to control robots generally involves the following tasks: (1) understanding the simulation tools, (2) creating the neural circuit in the neural simulator, (3) linking the simulated neural circuit with the environment of the agent and (4) programming the appropriate interface in the robot or agent to use the neural controller. The accomplishment of the above-mentioned tasks can be challenging, especially for undergraduate students or novice researchers. This paper presents an alternative tool which facilitates the simulation of simple SNN circuits using the multi-agent simulation and the programming environment Netlogo (educational software that simplifies the study and experimentation of complex systems). The engine proposed and implemented in Netlogo for the simulation of a functional model of SNN is a simplification of integrate and fire (I&F) models. The characteristics of the engine (including neuronal dynamics, STDP learning and synaptic delay) are demonstrated through the implementation of an agent representing an artificial insect controlled by a simple neural circuit. The setup of the experiment and its outcomes are described in this work

Antikaon production in nucleon-nucleon reactions near threshold

The antikaon production cross section from nucleon-nucleon reactions near threshold is studied in a meson exchange model. We include both pion and kaon exchange, but neglect the interference between the amplitudes. In case of pion exchange the antikaon production cross section can be expressed in terms of the antikaon production cross section from a pion-nucleon interaction, which we take from the experimental data if available. Otherwise, a $K^*$-resonance exchange model is introduced to relate the different reaction cross sections. In case of kaon exchange the antikaon production cross section is related to the elastic $KN$ and $\bar KN$ cross sections, which are again taken from experimental measurements. We find that the one-meson exchange model gives a satisfactory fit to the available data for the $NN\to NNK\bar K$ cross section at high energies. We compare our predictions for the cross section near threshold with an earlier empirical parameterization and that from phase space models.Comment: 16 pages, LaTeX, 5 postscript figures included, submitted to Z. Phys.

Searching for plasticity in dissociated cortical cultures on multi-electrode arrays

We attempted to induce functional plasticity in dense cultures of cortical cells using stimulation through extracellular electrodes embedded in the culture dish substrate (multi-electrode arrays, or MEAs). We looked for plasticity expressed in changes in spontaneous burst patterns, and in array-wide response patterns to electrical stimuli, following several induction protocols related to those used in the literature, as well as some novel ones. Experiments were performed with spontaneous culture-wide bursting suppressed by either distributed electrical stimulation or by elevated extracellular magnesium concentrations as well as with spontaneous bursting untreated. Changes concomitant with induction were no larger in magnitude than changes that occurred spontaneously, except in one novel protocol in which spontaneous bursts were quieted using distributed electrical stimulation

A importância dos princípios do marketing 3.0 nos processos e modelos da inovação - Caso InovCity Évora

A informação e o conhecimento estão cada vez mais democratizados. O marketing e a inovação tornaram-se parte de um processo aberto e compartilhado, acessível dentro e fora das organizações. Para as empresas que buscam ideias inovadoras, soluções de problemas e resultados criativos e este trabalho de projeto apresenta uma nova abordagem do marketing voltado para a inovação. O projeto foi elaborado em duas fases, teórico e prático. A revisão bibliográfica desenvolve conceitos, que influenciam diretamente o projeto e apresenta a metodologia escolhida e aplicada no caso InovCity Évora. A metodologia nomeada Ideas(R)evolution é um método experimental de aplicação de processos e de técnicas dinâmicas e criativas. Esta consiste num modelo de gestão de marca com base na co-criação e co-participação. Este estudo procurou perceber como o marketing e a inovação, influenciam o ambiente competitivo diante de instabilidades econômicas, tecnológicas e culturais. Apenas as empresas que se diferenciam têm conseguido, de fato, expandir seus mercados e criar uma vantagem competitiva. Em síntese, foi possível validar todos os objetivos por meio dos resultados e conclusões obtidas durante o decorrer do trabalho de projeto. A maioria dos autores de inovação e gestão, hoje, aplicam processos do marketing 3.0 utilizando a co-criação. Atravéz da participação como observadora tive acesso a todo o processo da aplicação do método Ideas(R)evolution até à observação da aplicação da metodologia ao caso Inovcity Évora. O projeto alcançou os objetivos solicitados pela empresa contratante a EDP. Os participantes dos workshops de criatividade “os stakeholders” ficaram satisfeitos com o processo e suas participações. A EDP incorporou estratégias do marketing 3.0 na cultura e estratégias organizacionais; ABSTRACT: Information and knowledge are increasingly democratized. Marketing and Innovation became part of an open and shared process, accessible within and outside organizations. This project presents a new approach to marketing directed towards innovation for companies seeking innovative ideas, creative problem resolutions and results. It was designed in two phases, a theoretical and a practical. The literature review shows concepts that influenced directly the project and the methodology applied in the InovCity Évora case. The methodology named Ideas (R) evolution is an experimental method characterized by the application of processes and dynamic and creative techniques based on a brand management model related with co-creation and co-participation. The present study aims to understand how marketing and innovation influence the competitive environment economic, technological and cultural instabilities. Only companies that manage to differentiate themselves are in fact able to expand their markets and have or maintain a competitive advantage. In summary, it was possible to validate all objectives through the results and conclusions reached during the course of the project. Today, most authors of innovation and management processes apply marketing 3.0 processes, using the co-creation. Through my participation as an observer I had access to the entire process from the application of the method to the analysis of the macro environment of the Ideas (R) evolution method in the InovCity Évora case. The project reached the requested objectives by the contracting company EDP. The “stakeholders”, the participants in the creativity workshops were also satisfied with the process and their participation during the process. The EDP, incorporated the 3.0 marketing strategies in its strategy and organizational culture

AFM, SEM and TEM Studies on Porous Anodic Alumina

Porous anodic alumina (PAA) has been intensively studied in past decade due to its applications for fabricating nanostructured materials. Since PAA’s pore diameter, thickness and shape vary too much, a systematical study on the methods of morphology characterization is meaningful and essential for its proper development and utilization. In this paper, we present detailed AFM, SEM and TEM studies on PAA and its evolvements with abundant microstructures, and discuss the advantages and disadvantages of each method. The sample preparation, testing skills and morphology analysis are discussed, especially on the differentiation during characterizing complex cross-sections and ultrasmall nanopores. The versatility of PAAs is also demonstrated by the diversity of PAAs’ microstructure

A comparative study on the mineralogy, chemical speciation, and combustion behavior of toxic elements of coal beneficiation products

The huge demand for high-quality coal in China has resulted in increased generation of preparation plant wastes of various properties. A series of beneficiation products collected from a preparation plant were characterized to understand their petrographic and mineralogical characteristics, as well as thermochemical and trace element behavior during combustion. The minerals in the Luling preparation plant wastes from Huaibei coalfield mainly included kaolinite and quartz, with minor calcite, ankerite, pyrite, illite, chalcopyrite, albite, K-feldspar, anatase/rutile, and iron-oxide minerals. Massive clay lumps of terrigenous origin, cleat-infilling carbonate, and pyrite of epigenetic origin were prone to be enriched in the middlings and coal gangue. Minor or trace heavy minerals also reported to the preparation plant wastes. The contents of low-density density vitrinite and liptinite were enhanced in the clean coal, while inertinite-maceral group were enriched in the middlings. The modes of occurrences of toxic elements differed between raw coal and the waste products; and their transformation behavior during heavy medium separation is largely controlled by clay minerals (V, Cr, Co, Sb, and Pb), carbonate minerals (Co and Pb), sulfide minerals (As, Cu, Ni, Cd, and Zn) and organic matters (V, Cr, Se, and Cu). Three groups were classified based on the volatile ratio (Vr) of toxic elements. Group 1 includes the highly volatile element Se with Vr &gt; 85%; Group 2 contained elements As, Pb, Zn, Cd and Sb, with the Vr in the range of 20&ndash;85% and V, Cr, Co, Ni and Cu with Vr less than 20% were placed into Group 3. Thermal reactivity of coal inferred from the combustion profiles could be significantly improved after coal beneficiation, whereas the increased inorganic components probably inhibited the thermal chemical reaction of wastes.<br style="line-height: normal; text-align: -webkit-auto; text-size-adjust: auto;" /

Factorizations of Elements in Noncommutative Rings: A Survey

We survey results on factorizations of non zero-divisors into atoms (irreducible elements) in noncommutative rings. The point of view in this survey is motivated by the commutative theory of non-unique factorizations. Topics covered include unique factorization up to order and similarity, 2-firs, and modular LCM domains, as well as UFRs and UFDs in the sense of Chatters and Jordan and generalizations thereof. We recall arithmetical invariants for the study of non-unique factorizations, and give transfer results for arithmetical invariants in matrix rings, rings of triangular matrices, and classical maximal orders as well as classical hereditary orders in central simple algebras over global fields.Comment: 50 pages, comments welcom