Web ontology representation and reasoning via fragments of set theory

In this paper we use results from Computable Set Theory as a means to represent and reason about description logics and rule languages for the semantic web. Specifically, we introduce the description logic \mathcal{DL}\langle 4LQS^R\rangle(\D)--admitting features such as min/max cardinality constructs on the left-hand/right-hand side of inclusion axioms, role chain axioms, and datatypes--which turns out to be quite expressive if compared with \mathcal{SROIQ}(\D), the description logic underpinning the Web Ontology Language OWL. Then we show that the consistency problem for \mathcal{DL}\langle 4LQS^R\rangle(\D)-knowledge bases is decidable by reducing it, through a suitable translation process, to the satisfiability problem of the stratified fragment $4LQS^R$ of set theory, involving variables of four sorts and a restricted form of quantification. We prove also that, under suitable not very restrictive constraints, the consistency problem for \mathcal{DL}\langle 4LQS^R\rangle(\D)-knowledge bases is \textbf{NP}-complete. Finally, we provide a $4LQS^R$-translation of rules belonging to the Semantic Web Rule Language (SWRL)

Improvements in the reconstruction of time-varying gene regulatory networks: dynamic programming and regularization by information sharing among genes

<b>Method:</b> Dynamic Bayesian networks (DBNs) have been applied widely to reconstruct the structure of regulatory processes from time series data, and they have established themselves as a standard modelling tool in computational systems biology. The conventional approach is based on the assumption of a homogeneous Markov chain, and many recent research efforts have focused on relaxing this restriction. An approach that enjoys particular popularity is based on a combination of a DBN with a multiple changepoint process, and the application of a Bayesian inference scheme via reversible jump Markov chain Monte Carlo (RJMCMC). In the present article, we expand this approach in two ways. First, we show that a dynamic programming scheme allows the changepoints to be sampled from the correct conditional distribution, which results in improved convergence over RJMCMC. Second, we introduce a novel Bayesian clustering and information sharing scheme among nodes, which provides a mechanism for automatic model complexity tuning. <b>Results:</b> We evaluate the dynamic programming scheme on expression time series for Arabidopsis thaliana genes involved in circadian regulation. In a simulation study we demonstrate that the regularization scheme improves the network reconstruction accuracy over that obtained with recently proposed inhomogeneous DBNs. For gene expression profiles from a synthetically designed Saccharomyces cerevisiae strain under switching carbon metabolism we show that the combination of both: dynamic programming and regularization yields an inference procedure that outperforms two alternative established network reconstruction methods from the biology literature

‘Movement as disclosive of being’ Merleau-Ponty: from the psychology of gestalt to the analysis of movement

In this essay we seek to clarify the meaning and theoretical implications of the statement by Merleau-Ponty contained in his 1953 course, Le Monde Sensible et le Monde de l’Expression, according to which movement is ‘revealing of being’. This analysis takes up and comments on chapter 7 of Koffka’s Principles of Gestalt Psychology (dedicated to the issue of movement) and related experiments in particular. We will show that Merleau-Ponty’s idea of ontology of movement emerges from his examination of several exemplary cases. This method of analysis brings to light an idea of similar phenomenology compatible with an experimental phenomenolog

The Train dynamics of wheel rail contact and longitudinal lateral interaction between vehicles

This paper is focused on the vehicle dynamics caused by the forces exchanged, through buffers and draw gears, by consecutive vehicles on a curve. The results have been obtained by adding a buffers/draw gears contact model on an existing multibody code, previously developed by the authors. The multibody code manages rigid bodies connected by elastic and rigid constraints; the wheel/rail contact model is three dimensional and employs an elastic constraint among wheel and rail. The wheel/rail contact is managed by means of a numerical model called TOAM (third order approximation method). Numerical tests and experimental validations of the proposed model are here presented, considering a train made by three vehicles, running on an S shaped curve, subjected to parametric compressive forces

Value-based design decision rationale documentation: Principles and empirical feasibility study

The explicit documentation of the rationale of design decisions is a practice generally encouraged, but rarely implemented in industry because of a variety of inhibitors. Methods proposed in the past for Design Decisions Rationale Documentation (DDRD) aimed to maximize benefits for the DDRD consumer by imposing on the producer of DDRD the burden to document all the potentially useful information. We propose here a compromise which consists in tailoring DDRD, based on its intended use or purpose. In our view, the adoption of a tailored DDRD, consisting only of the required set of information, would mitigate the effects of DDRD inhibitors. The aim of this paper is twofold: i) to discuss the application of Value-Based Software Engineering principles to DDRD, ii) to describe a controlled experiment to empirically analyze the feasibility of the proposed method. Results show that the level of utility related to the same category of DDRD information significantly changes depending on its purpose; such result is novel and it demonstrates the feasibility of the proposed value-based DDRD

Documenting design decision rationale to improve individual and team design decision making: An experimental evaluation

Individual and team decision-making have crucial influence on the level of success of every software project. Even though several studies were already conducted, which concerned design decision rationale documentation approaches, a few of them focused on performances and evaluated them in laboratory. This paper proposes a technique to document design decision rationale, and evaluates experimentally the impact such a technique has on effectiveness and efficiency of individual/team decision-making in presence of requirement changes. The study was conducted as a controlled experiment. Fifty post-graduate Master students performed in the role of experiment subjects. Documented design decisions regarding the Ambient Intelligence paradigm constituted the experiment objects. Main results of the experiment show that, for both individual and team-based decision-making, effectiveness significantly improves, while efficiency remains unaltered, when decision-makers are allowed to use, rather not use, the proposed design rationale documentation technique. Copyright 2006 ACM

An Efficient Approximate Algorithm for the k-th Selection Problem

We present an efficient randomized algorithm for the approximate k-th selection problem. It works in-place and it is fast and easy to implement. The running time is linear in the length of the input. For a large input set the algorithm returns, with high probability, an element which is very close to the exact k-th element. The quality of the approximation is analyzed theoretically and experimentally

Decidability results for classes of purely universal formulae and quantifiers elimination in Set Theory

A general mechanism to extend decision algorithms to deal with additional predicates is described. The only conditions imposed on the predicates is stability with respect to some transitive relations