Alberto Damiano

Knowledge Sifter: ontology-driven search over heterogeneous databases

Knowledge Sifter is a scaleable agent-based system that supports access to heterogeneous information sources such as the Web, open-source repositories, XML-databases and the emerging Semantic Web. User query specification is supported by a user agent that accesses multiple ontologies using an integrated conceptual model. A collection of cooperating agents supports interactive query specification, refinement, decomposition, and processing, as well as result ranking and presentation. The Knowledge Sifter architecture is general and modular so that ontologies and information sources can be easily incorporated. A proof-of-concept implementation depicts Knowledge Sifter using a domain ontology together with geospatial and semantic name services to enhance query formulation and to search image databases such as Lycos and TerraServer.

Knowledge Sifter: Agent-Based Ontology-Driven Search over Heterogeneous Databases Using Semantic Web Services

Knowledge Sifter is a scaleable agent-based system that supports access to heterogeneous information sources such as the Web, open-source repositories, XML-databases and the emerging Semantic Web. User query specification is supported by a user agent that accesses multiple ontologies using an integrated conceptual model expressed in the Web Ontology Language (OWL). A collection of cooperating agents supports interactive query specification and refinement, query decomposition, query processing, as well as result ranking and presentation. The Knowledge Sifter architecture is general and modular so that ontologies and information sources can be easily incorporated. A proof-of-concept implementation shows how Knowledge Sifter can search geo-spatial ontology services such as the USGS Geographic Names Information System (GNIS) and Princeton University’s WordNet as well as image databases including Lycos and TerraServer. Each Agent is implemented as a Web Service and the external sources are also accessed via Web Service Technology.

Information diffusion, Facebook clusters, and the simplicial model of social aggregation: a computational simulation of simplicial diffusers for community health interventions

Abstract By integrating the simplicial model of social aggregation with existing research on opinion leadership and diffusion networks, this article introduces the constructs of simplicial diffusers (mathematically defined as nodes embedded in simplexes; a simplex is a socially bonded cluster) and simplicial diffusing sets (mathematically defined as minimal covers of a simplicial complex; a simplicial complex is a social aggregation in which socially bonded clusters are embedded) to propose a strategic approach for information diffusion of cancer screenings as a health intervention on Facebook for community cancer prevention and control. This approach is novel in its incorporation of interpersonally bonded clusters, culturally distinct subgroups, and different united social entities that coexist within a larger community into a computational simulation to select sets of simplicial diffusers with the highest degree of information diffusion for health intervention dissemination. The unique contributions of the article also include seven propositions and five algorithmic steps for computationally modeling the simplicial model with Facebook data.

A surjectivity theorem for differential operators on spaces of regular functions

In this article we show that it is possible to construct a Koszul-type complex for maps given by suitable pairwise commuting matrices of polynomials. This result has applications to surjectivity theorems for constant coefficients differential operators of finite and infinite order. In particular, we construct a large class of constant coefficients differential operators which are surjective on the space of regular (or monogenic) functions on open convex sets.

Computational Methods for the Construction of a Class of Noetherian Operators

This paper presents some algorithmic techniques for computing explicitly the Noetherian operators associated with a class of ideals and modules over a polynomial ring. The procedures we include in this work can be easily encoded in computer algebra packages such as CoCoA [CoCoATeam 05].

New algebraic properties of biregular functions in 2 n quaternionic variables

In this article we exploit some general results on the tensor product of free resolutions to deduce important new algebraic properties of biregular functions in 2n quaternionic variables. In particular, we are able to construct a minimal resolution for the associated module and compute all the relevant graded Betti numbers. §Dedicated to Richard Delanghe on the occasion of his 65th birthday. This article is dedicated, with friendship and admiration, to Professor Richard Delanghe, who has done so much, as a mathematician and as a leader, to further the work on Clifford Analysis around the world.

Use of Genetic Algorithms with Multiple Metrics Aimed at the Optimization of Automotive Suspension Systems

Suspension models are highly multivariate and require a nonlinear system to model the movements and interaction of the parameters within the suspension system. Multiple metrics must be considered to determine an optimal result. This paper describes a system for the use of a Genetic Algorithm for the optimization of automotive suspension geometries, a description of the suspension model, and the scoring mechanism. The results of this model evaluate the impact of multiple independent metrics. A combined objective function score is determined with the assistance of a user selectable weighting of metrics. The optimization algorithm is also compared to a discrete grid search.

A New Dolbeault Complex in Quaternionic and Clifford Analysis

The papers introduces a new complex of differential forms which provides a fine resolution for the sheaf of regular functions in two quaternionic variables and the sheaf of monogenic functions in two vector variables. The paper announces some applications of this complex to the construction of sheaves of quaternionic and Clifford hyperfunctions as equivalence classes of such differential forms.

Dirac Operator in Several Variables and Combinatorial Identities

The Dolbeault sequence is a fundamental tool for many problems in the function theory of several complex variables. A lot of attention was paid in the last decades to its analogue in the function theory of several Clifford variables. The first operator in this resolution is the Dirac operator in several variables. The complete description is known in dimension 4 (i.e., in the case of quaternionic variables, see [1, 6, 4]). Much less is known in higher dimensions. The case of three variables was described completely (see [18]). The full description of the complex for all dimensions is not known at present. Even the case of the stable range (i.e., when the number of variables is less or equal to the half of dimension) is still not fully understood.There are two different approaches to the stable range case, one based on classical algebraic geometry (the Hilbert syzygy theory, see [8]), the other one on representation theory (differential invariants in certain parabolic geometries, see [14, 20]). Differentia...