Search results for "symbolic"
showing 10 items of 449 documents
Development of an IoT Environmental Monitoring Application with a Novel Middleware for Resource Constrained Devices
2014
In this paper the development of a Mobile Health monitoring system is described. The system combines user location data with air quality information provided by a heterogeneous sensing infrastructure providing users with advises about their daily exposure to air pollutants. The highly dynamic integration of different kind of nodes, mostly characterized by rather constrained resources, of this application is crucial to implement the Internet of Things vision, and requires powerful and effective programming methodologies to abstract implementation of high-level distributed processing from hardware dependencies. We then describe our programming methodology and our novel middleware supporting d…
An Embedded, FPGA-based Computer Graphics Coprocessor with Native Geometric Algebra Support
2009
The representation of geometric objects and their transformation are the two key aspects in computer graphics applications. Traditionally, computer-intensive matrix calculations are involved in modeling and rendering three-dimensional (3D) scenery. Geometric algebra (aka Clifford algebra) is attracting attention as a natural way to model geometric facts and as a powerful analytical tool for symbolic calculations. In this paper, the architecture of Clifford coprocessor (CliffoSor) is introduced. CliffoSor is an embedded parallel coprocessing core that offers direct hardware support to Clifford algebra operators. A prototype implementation on a programmable gate array (FPGA) board is detailed…
Fixed-size Quadruples for a New, Hardware-Oriented Representation of the 4D Clifford Algebra
2010
Clifford algebra (geometric algebra) offers a natural and intuitive way to model geometry in fields as robotics, machine vision and computer graphics. This paper proposes a new representation based on fixed-size elements (quadruples) of 4D Clifford algebra and demonstrates that this choice leads to an algorithmic simplification which in turn leads to a simpler and more compact hardware implementation of the algebraic operations. In order to prove the advantages of the new, quadruple-based representation over the classical representation based on homogeneous elements, a coprocessing core supporting the new fixed-size Clifford operands, namely Quad-CliffoSor (Quadruple-based Clifford coproces…
Accelerating Clifford Algebra Operations using GPUs and an OpenCL Code Generator
2015
Clifford Algebra (CA) is a powerful mathematical language that allows for a simple and intuitive representation of geometric objects and their transformations. It has important applications in many research fields, such as computer graphics, robotics, and machine vision. Direct hardware support of Clifford data types and operators is needed to accelerate applications based on Clifford Algebra. This paper proposes a mixed software-hardware system that exploits the computational power of Graphics Processing Units (GPUs) to accelerate Clifford operations. A code generator, namely OpenCLifford, is presented that automatically generates Java and C libraries for the direct support of Clifford ele…
Design Space Exploration of Parallel Embedded Architectures for Native Clifford Algebra Operations
2012
In the past few decades, Geometric or Clifford algebra (CA) has received a growing attention in many research fields, such as robotics, machine vision and computer graphics, as a natural and intuitive way to model geometric objects and their transformations. At the same time, the high dimensionality of Clifford algebra and its computational complexity demand specialized hardware architectures for the direct support of Clifford data types and operators. This paper presents the design space exploration of parallel embedded architectures for native execution of four-dimensional (4D) and five-dimensional (5D) Clifford algebra operations. The design space exploration has been described along wit…
Verification of Symbolic Distributed Protocols for Networked Embedded Devices
2020
The availability of versatile and interconnected embedded devices makes it possible to build low-cost networks with a large number of nodes running even complex applications and protocols in a distributed manner. Common tools used for modeling and verification, such as simulators, present some limitations as application correctness is checked off-board and only focuses on source code. Execution in the real network is thus excluded from the early stages of design and verification. In this paper, a system for modeling and verification of symbolic distributed protocols running on embedded devices is introduced. The underlying methodology is rooted in a symbolic programming paradigm that makes …
An FPGA Implementation of a Quadruple-Based Multiplier for 4D Clifford Algebra
2008
Geometric or Clifford algebra is an interesting paradigm for geometric modeling in fields as computer graphics, machine vision and robotics. In these areas the research effort is actually aimed at finding an efficient implementation of geometric algebra. The best way to exploit the symbolic computing power of geometric algebra is to support its data types and operators directly in hardware. However the natural representation of the algebra elements as variable-length objects causes some problems in the case of a hardware implementation. This paper proposes a 4D Clifford algebra in which the variable-length elements are mapped into fixed-length elements (quadruples). This choice leads to a s…
Within the symbolic world of the prehistoric hunters: A GIS-based and 3D model analysis of sites with complexes of linear incisions in western Sicily
2021
Abstract The prehistoric peopling of Sicily has left scattered traces of symbolic activities through well-known rock art expressions in caves and rock shelters located all around the island (among the most significant, the sites of Addaura, Racchio and Genovese). A peculiar phenomenon is the incision of linear signs, often grouped on the same rocky walls, hidden in fissures or placed at the entrance of the underground chambers of caves. In this report, we investigate a sample of these graphic expressions from a spatial and technical point of view. A GIS-based approach presents the territorial pattern providing insight, on a macroscale, into the intentional positioning of the sign complexes.…
Rappresentazioni e territorio nelle dinamiche del turismo: il caso della Lonely Planet Sicily
2018
L’attuale dibattito sul riordino territoriale del Paese rende nuovamente centrale il concetto di territorio che, da sempre, in una prospettiva geografica pone problemi definitori. Esso può essere, infatti, oggetto di produzioni simboliche e (ri)semantizzazioni in grado di ridefinirlo e di creare specifiche modalità di interazione. A questo proposito, il presente lavoro intende proporre una riflessione su alcune dinamiche di produzione e riproduzione simbolica che interessano il concetto di territorio nel turismo, ambito in cui si può osservare una relazione diretta tra rappresentazione del territorio (intesa anche come narrazione) e possibilità d’azione. In particolare, attraverso il caso s…