Search results for "temi"

Numerical experiments with a parallel fast direct elliptic solver on Cray T3E

1997

A parallel fast direct O(N log N) solver is shortly described for linear systems with separable block tridiagonal matrices. A good parallel scalability of the proposed method is demonstrated on a Cray T3E parallel computer using MPI in communication. Also, the sequential performance is compared with the well-known BLKTRI-implementation of the generalized. cyclic reduction method using a single processor of Cray T3E.

Performing transnational family with the affordances of mobile apps : a case study of Polish mothers living in Finland

2020

Affordances provided by digital technologies and mobile apps (WhatsApp, Skype, Messenger) help in maintaining familyhood. These mobile apps enable the creation of in-app family groups. They also afford image sharing, which is used for phatic purposes. Digital connectivity provides the illusions of togetherness and belonging, and allows for performing family in a transnational context (emotional transnationalism). However, it also generates the feelings of guilt through infrequent communication. In the auto-driven visual elicitation interviews, the study looks at family constellations and technologically mediated communication from the perspective of five Polish mothers living in Finland. Ap…

Conceptual representations of actions for autonomous robots

2001

An autonomous robot involved in long and complex missions should be able to generate, update and process its own plans of action. In this perspective, it is not plausible that the meaning of the representations used by the robot is given from outside the system itself. Rather, the meaning of internal symbols must be firmly anchored to the world through the perceptual abilities and the overall activities of the robot. According to these premises, in this paper we present an approach to action representation that is based on a "conceptual" level of representation, acting as an intermediate level between symbols and data coming from sensors. Symbolic representations are interpreted by mapping …

Anchoring symbols to conceptual spaces: the case of dynamic scenarios.

2003

In recent years, there have been several proposals for the realization of models inspired to biological solutions for pattern recognition. In this work we propose a new approach, based on a hierarchical modular structure, to realize a system capable to learn by examples and recognize objects in digital images. The adopted techniques are based on multiresolution image analysis and neural networks. Performance on two different data sets and experimental timings on a single instruction multiple data (SIMD) machine are also reported.

Grounding ontologies in the external world

2017

The paper discusses a case study of grounding an ontology in the external world by a cognitive architecture for robot vision developed at the RoboticsLab of the University of Palermo. The architecture aims at representing symbolic knowledge extracted from visual data related to static and dynamic scenarios. The central assumption is the principled integration of a robot vision system with a symbolic system underlying the knowledge representation of the scene. Such an integration is based on a conceptual level of representation intermediate between the sub-symbolic processing of visual data and the declarative style employed in the ontological representation.

Conceptual spaces for computer vision representations

2001

A framework for high-level representations in computer vision architectures is described. The framework is based on the notion of conceptual space. This approach allows us to define a conceptual semantics for the symbolic representations of the vision system. In this way, the semantics of the symbols can be grounded to the data coming from the sensors. In addition, the proposed approach generalizes the most popular frameworks adopted in computer vision.

An algebra for the manipulation of conceptual spaces in cognitive agents

2013

According to Gärdenfors, the theory of conceptual spaces describes a level of representation present in some cognitive agents between a sub-conceptual and a symbolic level of representation. In contrast to a large part of contemporary philosophical speculation on these matters for which concepts and conceptual content are propositional, conceptual spaces provide a geometric framework for the representation of concepts. In this paper we introduce an algebra for the manipulation of different conceptual spaces in order to formalise the process whereby an artificial agent rearranges its internal conceptual representations as a consequence of its perceptions, which are here rendered in terms of …

1986

An osmotic pressure equation proposed over 50 years ago is found to be consistent with the des Cloizeaux scaling relation for semi-dilute polymer solutions in good solvents. With a physically plausible modification, the equation can also give a satisfactory representation of dilute solutions and of the cross-over to the semi-dilute regime.

Nuovi paradigmi del design. Visualizzazione interattiva e configuratori di prodotto.

2015

Disegno e progetto sono legati l’un l’altro e costituiscono un sistema di pensiero in cui, da sempre, è impossibile considerarli semparatamente. Pochi ma significativi esempi: codifica dell’assonometria e produzione industriale; curve di Bezier e forme di automobili; stampanti 3D e microproduzione. Anche oggi il connubio tra sistemi di visualizzazione e web sta cambiando il modo di vedere il prodotto e i processi di progettazione. Gli esiti di questo processo sono, tra gli altri, i configuratori di prodotto, software capaci di far prevedere un oggetto e le sue declinazioni. L’introduzione dei configuratori pone interrogativi di rilievo sul delicato rapporto tra rappresentazione, design e ma…

Interacting processes in protein coagulation

1999

A strong interest is currently focused on protein self-association and deposit. This usually involves conformational changes of the entire protein or of a fragment. It can occur even at low concentrations and is responsible for pathologies such as systemic amyloidosis, Alzheimer's and Prion diseases, and other neurodegenerative pathologies. Readily available proteins, exhibiting at low concentration self-association properties related to conformational changes, offer very convenient model systems capable of providing insight into this class of problems. Here we report experiments on bovine serum albumin, showing that the process of conformational change of this protein towards an intermedia…