On Safe Folding

In [3] a general fold operation has been introduced for definite programs wrt computed answer substitution semantics. It differs from the fold operation defined by Tamaki and Sato in [26,25] because its application does not depend on the transformation history. This paper extends the results in [3] by giving a more powerful sufficient condition for the preservation of computed answer substitutions. Such a condition is meant to deal with the critical case when the atom introduced by folding depends on the clause to which the fold applies. The condition compares the dependency degree between the fonding atom and the folded clause, with the semantic delay between the folding atom and the ones to be folded. The result is also extended to a more general replacement operation, by showing that it can be decomposed into a sequence of definition, general folding and unfolding operations

Adaptive Cluster Expansion for Inferring Boltzmann Machines with Noisy Data

We introduce a procedure to infer the interactions among a set of binary variables, based on their sampled frequencies and pairwise correlations. The algorithm builds the clusters of variables contributing most to the entropy of the inferred Ising model, and rejects the small contributions due to the sampling noise. Our procedure successfully recovers benchmark Ising models even at criticality and in the low temperature phase, and is applied to neurobiological data.Comment: Accepted for publication in Physical Review Letters (2011

Probing Low Energy Neutrino Backgrounds with Neutrino Capture on Beta Decaying Nuclei

We study the interaction of low energy neutrinos on nuclei that spontaneously undergo beta decay showing that the product of the cross section times neutrino velocity takes values as high as 10^{-42} cm^2 c for some specific nuclei that decay via allowed transitions. The absence of energy threshold and the value of the cross section single out these processes as a promising though very demanding approach for future experiments aimed at a direct detection of low energy neutrino backgrounds such as the cosmological relic neutrinos.Comment: Includes a discussion of local relic neutrino density effect on neutrino capture rate. Accepted for publication in JCA

Exponentially hard problems are sometimes polynomial, a large deviation analysis of search algorithms for the random Satisfiability problem, and its application to stop-and-restart resolutions

A large deviation analysis of the solving complexity of random 3-Satisfiability instances slightly below threshold is presented. While finding a solution for such instances demands an exponential effort with high probability, we show that an exponentially small fraction of resolutions require a computation scaling linearly in the size of the instance only. This exponentially small probability of easy resolutions is analytically calculated, and the corresponding exponent shown to be smaller (in absolute value) than the growth exponent of the typical resolution time. Our study therefore gives some theoretical basis to heuristic stop-and-restart solving procedures, and suggests a natural cut-off (the size of the instance) for the restart.Comment: Revtex file, 4 figure

On the slip-weakening behavior of rate- and state-dependent constitutive laws

We study the dynamic traction behavior within the cohesive zone during the propagation of earthquake ruptures adopting rate and state dependent constitutive relations. The resulting slip weakening curve displays an equivalent slip weakening distance (D0_eq), which is different from the parameter L controlling the state variable evolution. The adopted constitutive parameters (a, b, L) control the slip weakening behavior and the absorbed fracture energy. The dimension of the nucleation patch scales with L and not with D0_eq. We propose a scaling relation between these two lengthscale parameters which prescribes that D0_eq/L ~ 15

Relaxation and Metastability in the RandomWalkSAT search procedure

An analysis of the average properties of a local search resolution procedure for the satisfaction of random Boolean constraints is presented. Depending on the ratio alpha of constraints per variable, resolution takes a time T_res growing linearly (T_res \sim tau(alpha) N, alpha < alpha_d) or exponentially (T_res \sim exp(N zeta(alpha)), alpha > alpha_d) with the size N of the instance. The relaxation time tau(alpha) in the linear phase is calculated through a systematic expansion scheme based on a quantum formulation of the evolution operator. For alpha > alpha_d, the system is trapped in some metastable state, and resolution occurs from escape from this state through crossing of a large barrier. An annealed calculation of the height zeta(alpha) of this barrier is proposed. The polynomial/exponentiel cross-over alpha_d is not related to the onset of clustering among solutions.Comment: 23 pages, 11 figures. A mistake in sec. IV.B has been correcte

Monitoring pit and fissures using transparent sealant and fluorescence intraoral camera, 12 months follow up

The aim of this in vivo study is to report on the combined use of a fluorescence intraoral camera and transparent sealant for the clinical monitoring of pits and fissures. 96 permanent molars with a ICDAS II code 0, 1, or 2, (in 48 patients aged 12–14) were registered at the First Observation Unit (Oral and Maxillofacial Sciences Department), Sapienza University, Rome. Clinically selected teeth were double-checked using a VistaCam iX Proof (Durr Dental AG) and sealed with a transparent sealant (ControlSeal, VOCO GmbH), following the established indications for use if a pit and fissure condition was confirmed within the camera’s internal cutoff point of 1.5 (“early enamel demineralization”). Clinical followup was performed using VistaCam at 6 and 12 months to assess sealant retention and any demineralization trend. At baseline, 57.4% of the registered teeth were sound, both visually and when using the fluorescence camera, 42.6% presented an early demineralization (&lt;1.5 with VistaCam and ICDAS II 1- 2). Subsequent VistaCam assessment of surfaces underlying the transparent sealant totally confirmed initial evaluations. Complete sealant retention rated 95% at 6 months, and 91% at 12 months. No case of complete detachment was observed. At the 12-month follow-up, VistaCam measurements resulted stable in the whole sample, except for one permanent molar, which presented a demineralization increment and partial sealant retention. Visual and fluorescence assessments were consistent and feasible. Incomplete sealant retention occurred in 5% of cases at 6 months and 9% of cases at 12 months and was probably due to procedure imperfections. The combined use of transparent sealant and a fluorescence camera shows clinical effectiveness and diagnostic efficacy for occlusal surface monitoring

TOWARDS A NOVEL APPROACH TO GEODESIGN ANALYTICS

The adoption of sustainability principles in current European regulatory framework which affect spatial planning and environmental protection, such as Directive 2001/42/C, introduced the need for collaboration and participation in spatial planning practices aiming at achieving more evidence-based, transparent and democratic decision making. However, the involvement of a wide range of actors, along with traditional collaborative and participatory methods, makes it often diffi cult to grasp the dynamics which drive the process towards the fi nal decision. Emerging design methodologies and increased recourse to advanced information technologies promise unprecedented opportunities not only for applying a system approach and coordinating involved actors, but also for tracking the evolution of the design alternatives toward the fi nal plan. In this context, this paper explores the potential offered by the collaborative Planning Support System Geodesignhub to ease and record the process workfl ow of geodesign studies. The paper describes underlying theories, research questions formulation and the fi rst results of the analysis of empirical data on the Cagliari Geodesign case study. The set of variables and relations identifi ed in this research endeavor represents the fi rst effort towards the development of an operation framework for geodesign process analysis, which may potentially contribute to clarify the relationships between the knowledge base and the actors in the planning process. The aim is to earning a deeper understanding of the process dynamics for more informed, transparent, and democratic planning, design and decision-making. KEYWORD