Mathematical Operations (mathematical + operations)

Distribution by Scientific Domains

Selected Abstracts

xBCI: A Generic Platform for Development of an Online BCI System

I Putu Susila Non-member
Abstract A generic platform for realizing an online brain,computer interface (BCI) named xBCI was developed. The platform consists of several functional modules (components), such as data acquisition, storage, mathematical operations, signal processing, network communication, data visualization, experiment control, and real-time feedback presentation. Users can easily build their own BCI systems by combining the components on a graphical-user-interface (GUI) based diagram editor. They can also extend the platform by adding components as plug-ins or by creating components using a scripting language. The platform works on multiple operating systems and supports parallel (multi-threaded) data processing and data transfer to other PCs through a network transmission control protocol/internet protocol or user datagram protocol (TCP/IP or UDP). A BCI system based on motor imagery and a steady-state visual evoked potential (SSVEP) based BCI system were constructed and tested on the platform. The results show that the platform is able to process multichannel brain signals in real time. The platform provides users with an easy-to-use system development tool and reduces the time needed to develop a BCI system. Copyright 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source]

Real-time signal processing for high-density microelectrode array systems

K. Imfeld
Abstract The microelectrode array (MEA) technology is continuously progressing towards higher integration of an increasing number of electrodes. The ensuing data streams that can be of several hundreds or thousands of Megabits/s require the implementation of new signal processing and data handling methodologies to substitute the currently used off-line analysis methods. Here, we present one approach based on the hardware implementation of a wavelet-based solution for real-time processing of extracellular neuronal signals acquired on high-density MEAs. We demonstrate that simple mathematical operations on the discrete wavelet transform (DWT) coefficients can be used for efficient neuronal spike detection and sorting. As the DWT is particularly well suited for implementation on dedicated hardware, we elaborated a wavelet processor on a field programmable gate array (FPGA) in order to compute the wavelet coefficients on 256 channels in real-time. By providing sufficient hardware resources, this solution can be easily scaled up for processing more electrode channels. Copyright 2008 John Wiley & Sons, Ltd. [source]

Beyond Conceptual Change: Using Representations to Integrate Domain-Specific Structural Models in Learning Mathematics

Florence Mihaela Singer
ABSTRACT, Effective teaching should focus on representational change, which is fundamental to learning and education, rather than conceptual change, which involves transformation of theories in science rather than the gradual building of knowledge that occurs in students. This article addresses the question about how to develop more efficient strategies for promoting representational change across cognitive development. I provide an example of an integrated structural model that highlights the underlying cognitive structures that connect numbers, mathematical operations, and functions. The model emphasizes dynamic multiple representations that students can internalize within the number line and which lead to developing a dynamic mental structure. In teaching practice, the model focuses on a counting task format, which integrates a variety of activities, specifically addressing motor, visual, and verbal skills, as well as various types of learning transfer. [source]

2D-Fractal Based Algorithms for Fine and Ultrafine Particulate Solids Systems Characterization

Giuseppe Bonifazi
Abstract Fractal geometry concerns the study of non-Euclidean geometrical figures generated by a recursive sequence of mathematical operations. The proposed 2D-fractal approach was applied to characterise the image structure and texture generated by fine and ultrafine particles when impacting on a flat surface. The work was developed with reference to particles usually produced in the ornamental stone sector during the different working phases carried out in dry conditions. Specific milling actions have been performed at a laboratoty scale on different ornamental stone products, in order to generate different particle populations to utilize in the study. The aim of the work was to develop a simple, reliable and low cost analytical set of procedures with the ability to establish correlations between particles detected by fractal characteristics and their classical attributes, e.g., i) size class distribution, ii) shape, iii) composition, etc. Such a logic should constitute the core of a control engine with the ability to optimize dust capture abatement strategies, according to produced dusts characteristics. [source]