Inter-spikes-intervals exponential and gamma distributions study of neuron firing rate for SVITE motor control model on FPGA

This paper presents a statistical study on a neuro-inspired spike-based implementation of the Vector-Integration-To-End-Point motor controller (SVITE) and compares its deterministic neuron-model stream of spikes with a proposed modification that converts the model, and thus the controller, in a Poisson like spike stream distribution. A set of hardware pseudo-random numbers generators, based on a Linear Feedback Shift Register (LFSR), have been introduced in the neuron-model so that they reach a closer biological neuron behavior. To validate the new neuron-model behavior a comparison between the Inter-Spikes-Interval empirical data and the Exponential and Gamma distributions has been carried out using the Kolmogorov–Smirnoff test. An in-hardware validation of the controller has been performed in a Spartan6 FPGA to drive directly with spikes DC motors from robotics to study the behavior and viability of the modified controller with random components. The results show that the original deterministic spikes distribution of the controller blocks can be swapped with Poisson distributions using 30-bit LFSRs. The comparative between the usable controlling signals such as the trajectory and the speed profile using a deterministic and the new controller show a standard deviation of 11.53 spikes/s and 3.86 spikes/s respectively. These rates do not affect our system because, within Pulse Frequency Modulation, in order to drive the motors, time length can be fixed to spread the spikes. Tuning this value, the slow rates could be filtered by the motor. Therefore, this SVITE neuro-inspired controller can be integrated within complex neuromorphic architectures with Poisson-like neurons

A maturidade da dívida das pequenas e médias empresas industriais portuguesas

O presente trabalho centra-se no estudo da maturidade da dívida das PME industriais portuguesas. Para o efeito, após um breve enquadramento teórico sobre o tema, é analisada uma amostra de 800 empresas, procurando perceber quais os seus principais determinantes. Comparando os resultados obtidos com a evidência empírica internacional, focalizada sobretudo em grandes empresas cotadas e inseridas em mercados financeiros fortemente desintermediados, verificamos que a maturidade da dívida das PME industriais portuguesas reage da mesma forma a factores como: o grau de endividamento, a adequação à maturidade dos activos, o grau de libertação de fundos e a existência de garantias reais. Em contrapartida, a dimensão, sector de actividade e o nível de assimetria de informação parecem constituir factores irrelevantes. Obtém-se ainda que as opções de crescimento têm um efeito oposto ao esperado e que não se verifica uma relação perfeita, do tipo U invertido, entre o risco de liquidez e a maturidade

Activity providers for Inven!RA

This report details the operation of Web services for platforms implementing the Inven!RA architecture and the data formats for parameter passing and responses.N/

Spatio-temporal conjecture for diffusion

We present here a conjecture about the equivalence between the noise density of states of a system governed by a generalized Langevin equation and the fluctuation in the energy density of states in a Hamiltonian system. We present evidence of this for a disordered Heisenberg system.Comment: 6 pages, 1 figure. Submitted to Physica

Gamification badges and ratings: impact in a academic social network

The article describes the Impact of using Gamification Elements like Badges, Status Bar and a Rating System on the Interaction, Collaboration, Cooperation and the Presences of the Community of Inquiry Framework, inside an Academic Social Platform. We used a Design Base Research Methodology with Mixed Methods. We started by collecting opinions of users using semistructured interviews. The results from coding, informed on the construction of a gamified prototype, made with Elgg. Then Usability tests were conducted and the data helped refine the subsequent implementation. A Survey was deployed, Observations were made, and we gathered some Analytics. Results are presented congruent to the iterations and discussed. Some indications for the use of Badges and the implementation of Gamification are considered.Laboratório de Educação a Distância e eLearning (LE@D) http://lead.uab.pt/ - Projeto Educação Online e Web Socialinfo:eu-repo/semantics/publishedVersio

Projecto curricular : mudança de práticas ou oportunidade perdida?

Com base nas opiniões de uma amostra representativa dos professores que, no ano escolar de 2004/2005, leccionaram em escolas oficiais do 2º e 3º ciclos do Ensino Básico do distrito do Porto, procuramos ao longo deste texto problematizar a importância que consignam ao projecto curricular como elemento estruturante das suas práticas pedagógicas e como factor de melhoria do seu desenvolvimento profissional.Based on feedback from a representative sample of teachers who, in the 2004/2005 school year, taught in the 2nd and 3rd cycles of basic education in public schools, located in the district of Porto, the authors analyze the importance that teachers assign to the curricular project as a structural element of their pedagogical practices and as an improvement factor of their professional development

Live Demonstration: Real-time neuro-inspired sound source localization and tracking architecture applied to a robotic platform

This live demonstration presents a sound source localization and tracking system implemented with Spike Signal Processing (SSP) building blocks on FPGA devices. The system architecture is based on the ability of the mammalian auditory system to locate the direction of a sound in the horizontal plane using the interaural intensity difference. We used a binaural Neuromorphic Auditory Sensor to obtain spike rates similar to those generated by the inner hair cells of the human auditory system and the component that obtains the interaural intensity difference is inspired by the lateral superior olive. The spike stream that represents the interaural intensity difference is used to turn a robotic platform towards the sound source direction. The system was tested with pure tones (1-kHz, 2.5-kHz and 5- kHz sounds) with an average error of 2.32 degrees.Ministerio de Economía y Competitividad TEC2016-77785-

Gamificação de uma plataforma social académica numa universidade de ensino a distância

O Vol 2 (1) 2019 é dedicado à problemática das Competências Digitais.O nosso estudo propôs a implementação de Gamificação numa Plataforma Social Académica de uma Universidade Virtual. Gamificação foi definida como o uso de elementos derivados dos jogos em contextos que não são jogos. Adaptando-a ao nosso contexto, quisemos verificar de que forma a sua implementação influenciava a Interação, Colaboração, Cooperação e Aprendizagem Social e ainda as presenças da Comunidade de Investigação, no espaço da Plataforma. Para isso usámos uma Metodologia de Design Based Research numa configuração de Métodos Mistos. Identificámos como foco de análise as formas sociais para a aprendizagem. Começámos por recolher opiniões dos utilizadores, usando entrevistas semi-estruturadas. Os resultados, informaram na construção de um protótipo “gamificado” construído com a ferramenta Elgg. Seguidamente efetuaram-se testes de usabilidade, recolhendo dados da performance e das opiniões dos utilizadores e foi efetuada uma implementação gamificada. Foram depois enviados questionários aos utilizadores e recolhidas estatísticas do uso. Os dados foram descritos, analisados e discutidos, segundo uma ordem cronológica. É discutido o impacto da implementação nas dimensões propostas e possibilidades de investigação futuras.The article reports on the implementation of Gamification in a Social Platform of an Open University. Gamification is the use of game elements in non-game context. We adapted the implementation to context, to inspect the impact on the Interaction, Collaboration, Cooperation, Social Learning and on the Community of Inquiry. We used Design Based Research in a Mixed-Methods configuration. We looked at the Social Forms for Learning as a lens for the Elements. We present our study in a chronological order, explaining how each phase leads to the other. We first gathered information from the users of the academic platform via semi-structured interviews. We then designed a prototype with the Elgg engine, containing Gamification Elements. We made usability tests and gathered data from users´ performance and opinions. After we designed a second implementation, this time for students enrolled in different curricular units. This time we deployed a Survey and gathered information about the use of the platform. Lastly, we present our results discussing the impact on the proposed dimensions, and making suggestions for future research.info:eu-repo/semantics/publishedVersio

Using choreographies to support the gamification process on the development of an application to reduce electricity costs

Building automation systems contribute to reduce electricity costs by managing distributed energy resources in an efficient way. However, a large share of consumption cannot be optimized through automation alone, since it mainly depends on human interactions. Gamification can be used as one form of changing users’ behaviours [1], but its implementation does require assumptions on the behaviour patterns that need to be identified, encouraged, or discouraged. To tackle this problem, we propose a framework that joins building automation solutions with gamification techniques to enable behavioural demand response.info:eu-repo/semantics/publishedVersio

SVITE: A Spike-Based VITE Neuro-Inspired Robot Controller

This paper presents an implementation of a neuro-inspired algorithm called VITE (Vector Integration To End Point) in FPGA in the spikes domain. VITE aims to generate a non-planned trajectory for reaching tasks in robots. The algorithm has been adapted to work completely in the spike domain under Simulink simulations. The FPGA implementation consists in 4 VITE in parallel for controlling a 4-degree-of-freedom stereo-vision robot. This work represents the main layer of a complex spike-based architecture for robot neuro-inspired reaching tasks in FPGAs. It has been implemented in two Xilinx FPGA families: Virtex-5 and Spartan-6. Resources consumption comparative between both devices is presented. Results obtained for Spartan device could allow controlling complex robotic structures with up to 96 degrees of freedom per FPGA, providing, in parallel, high speed connectivity with other neuromorphic systems sending movement references. An exponential and gamma distribution test over the inter spike interval has been performed to proof the approach to the neural code proposed.Ministerio de Economía y Competitividad TEC2012-37868-C04-0