The PITA System: Tabling and Answer Subsumption for Reasoning under Uncertainty

Many real world domains require the representation of a measure of uncertainty. The most common such representation is probability, and the combination of probability with logic programs has given rise to the field of Probabilistic Logic Programming (PLP), leading to languages such as the Independent Choice Logic, Logic Programs with Annotated Disjunctions (LPADs), Problog, PRISM and others. These languages share a similar distribution semantics, and methods have been devised to translate programs between these languages. The complexity of computing the probability of queries to these general PLP programs is very high due to the need to combine the probabilities of explanations that may not be exclusive. As one alternative, the PRISM system reduces the complexity of query answering by restricting the form of programs it can evaluate. As an entirely different alternative, Possibilistic Logic Programs adopt a simpler metric of uncertainty than probability. Each of these approaches -- general PLP, restricted PLP, and Possibilistic Logic Programming -- can be useful in different domains depending on the form of uncertainty to be represented, on the form of programs needed to model problems, and on the scale of the problems to be solved. In this paper, we show how the PITA system, which originally supported the general PLP language of LPADs, can also efficiently support restricted PLP and Possibilistic Logic Programs. PITA relies on tabling with answer subsumption and consists of a transformation along with an API for library functions that interface with answer subsumption

Actual Causation in CP-logic

Given a causal model of some domain and a particular story that has taken place in this domain, the problem of actual causation is deciding which of the possible causes for some effect actually caused it. One of the most influential approaches to this problem has been developed by Halpern and Pearl in the context of structural models. In this paper, I argue that this is actually not the best setting for studying this problem. As an alternative, I offer the probabilistic logic programming language of CP-logic. Unlike structural models, CP-logic incorporates the deviant/default distinction that is generally considered an important aspect of actual causation, and it has an explicitly dynamic semantics, which helps to formalize the stories that serve as input to an actual causation problem

SWISH: SWI-Prolog for Sharing

Recently, we see a new type of interfaces for programmers based on web technology. For example, JSFiddle, IPython Notebook and R-studio. Web technology enables cloud-based solutions, embedding in tutorial web pages, atractive rendering of results, web-scale cooperative development, etc. This article describes SWISH, a web front-end for Prolog. A public website exposes SWI-Prolog using SWISH, which is used to run small Prolog programs for demonstration, experimentation and education. We connected SWISH to the ClioPatria semantic web toolkit, where it allows for collaborative development of programs and queries related to a dataset as well as performing maintenance tasks on the running server and we embedded SWISH in the Learn Prolog Now! online Prolog book.Comment: International Workshop on User-Oriented Logic Programming (IULP 2015), co-located with the 31st International Conference on Logic Programming (ICLP 2015), Proceedings of the International Workshop on User-Oriented Logic Programming (IULP 2015), Editors: Stefan Ellmauthaler and Claudia Schulz, pages 99-113, August 201

Introduzione all'Intelligenza Artificiale

The paper presents an introduction to Artificial Intelligence (AI) in an accessible and informal but precise form. The paper focuses on the algorithmic aspects of the discipline, presenting the main techniques used in AI systems groped in symbolic and subsymbolic. The last part of the paper is devoted to the discussion ongoing among experts in the field and the public at large about on the advantages and disadvantages of AI and in particular on the possible dangers. The personal opinion of the author on this subject concludes the paper. ----- L'articolo presenta un'introduzione all'Intelligenza Artificiale (IA) in forma divulgativa e informale ma precisa. L'articolo affronta prevalentemente gli aspetti informatici della disciplina, presentando le principali tecniche usate nei sistemi di IA divise in simboliche e subsimboliche. L'ultima parte dell'articolo presenta il dibattito in corso tra gli esperi e il pubblico su vantaggi e svantaggi dell'IA e in particolare sui possibili pericoli. L'articolo termina con l'opinione dell'autore al riguardo.Comment: 27 pages, in Italia

Finanzierung von medizinischen Verbrauchsgütern bei Spitex-Dienstleistern : wie geht es weiter?

Seit Januar 2018 müssen die Krankenversicherungen medizinische Verbrauchsgüter, die von Fachpersonen an Patienten/Patientinnen zu Hause angewendet werden, nicht mehr bezahlen. Dieser Artikel untersucht die Implikationen dieser veränderten Vergütungspraxis. Werden die Spitex-Organisationen diese Kosten selber tragen müssen? Werden die Kantone in die Rolle als Restfinanzierer treten, und welches Vergütungssystem werden sie allenfalls einführen? Welche Konsequenzen wird der Systemwechsel für die Versorgung im Bereich der Pflege zu Hause haben? Der Artikel gibt einen Überblick über die politische und rechtliche Entwicklung auf Bundesebene und zeigt, wie sich die Situation der verschiedenen Akteure im Bereich Pflege zu Hause dadurch verändert hat. Auch werden Hypothesen unter der Prämisse aufgestellt, dass die seit Januar 2018 geltende Regelung in Zukunft beibehalten würde, und parlamentarische Vorstösse somit erfolglos blieben. Dies führt zum Ergebnis, dass der kantonale Spielraum bei der Gestaltung eines Vergütungssystems zu heterogenen Lösungen führen könnte. Pauschale Beiträge der Kantone für Pflegematerial (pro Patient/Patientin und Tag) hätten stärkere Fehlanreize für die Leistungserbringer als differenzierte Vergütungssysteme (nach Patiententyp/Pflegematerial) und könnten die Versorgung beeinflussen. Die Qualität der angewendeten medizinischen Verbrauchsgüter könnte dadurch sinken und der Grundsatz «ambulant vor stationär» ausgehebelt werden. Aus Sicht der Leistungserbringer wäre damit zu rechnen, dass der finanzielle Druck ansteigt und dass Einsparungspotentiale konsequenter genutzt werden müssten, um das ökonomische Bestehen zu sichern

From the global scale to the Mediterranean plate kinematics

Plate motions with respect to the mantle represent the most direct evidence to understand the origin of plate tectonic processes. The research here described has the aim to improve the knowledge on the global scale plate kinematics in “absolute” reference frames, or better, relative to the mantle, incorporating both geological–geophysical and space geodesy data. Geophysical and geological signatures of subduction and rift zones independently show a global polarity of current plate motions, suggesting a west-ward displacement of the whole lithosphere relative to the underlying mantle. We analytically modeled this tectonic pattern in a suitable selected hotspot framework, taking into account variable depths of the hotspot source, obtaining new plate angular velocities and their uncertainties, by least squares inversion. Then, we focused our attention on the Italian area estimating the velocity field from continuous GPS observations both relative to Eurasia, and relative to the mantle, applying the global model previously estimated. However, the presence of the Apennine subduction, having more or less the same extent of the investigated area, makes locally less reliable our global model. Consequently, we applied a simple kinematic model to estimate the rates and spatial pattern of the subduction along the Apennines. The variable rates inferred after our analysis, better reconcile if the subduction process is conceived as a passive rather than active feature. Then, the analysis came back again to the global scale and to the basic argument if plates are passively riding along on the top of a mantle convection cell, or whether the plates themselves are active drivers. On the other hand, if plate motion occurs as an ordered undulated west-directed flow, the net-rotation of the lithosphere emerges as a passive process active at global scale, and then, it can be driven only by external forces. Thus, the last part of this research has been dedicated to find the experimental evidences connecting the tectonic processes to the Earth's rotation and the tidal drag

Quantum Weighted Model Counting

In Weighted Model Counting (WMC) we assign weights to Boolean literals and we want to compute the sum of the weights of the models of a Boolean function where the weight of a model is the product of the weights of its literals. WMC was shown to be particularly effective for performing inference in graphical models, with a complexity of $O(n2^w)$ where $n$ is the number of variables and $w$ is the treewidth. In this paper, we propose a quantum algorithm for performing WMC, Quantum WMC (QWMC), that modifies the quantum model counting algorithm to take into account the weights. In turn, the model counting algorithm uses the algorithms of quantum search, phase estimation and Fourier transform. In the black box model of computation, where we can only query an oracle for evaluating the Boolean function given an assignment, QWMC solves the problem approximately with a complexity of $\Theta(2^{\frac{n}{2}})$ oracle calls while classically the best complexity is $\Theta(2^n)$, thus achieving a quadratic speedup

Morphological updating on the basis of integrated DTMs: study on the Albano and Nemi craters

The Colli Albani Volcano has recently developed particular interest in the geophysical community for some peculiar characteristics imputable to a recent residual volcanic activity, thus evidencing that it cannot be considered extinguished yet. On April 2006 an airborne laser scanning (ALS) survey of the Albano and Nemi craters has been carried out to obtain a high resolution digital terrain model (DTM) of the area. We have compared the accuracy of the ALS heights with those obtained by a fast GPS kinematic survey, obtaining maximum deviation within 50 cm. Then, we have integrated the ALS survey of the craters and the bathymetry of the Albano lake to achieve a complete DTM, useful for morphological studies. In addition, with a GNSS/RTK survey (July 2007) we have estimated the Albano and Nemi mean lake levels respectively at 288.16 m and 319.02 m (asl). Based on the integrated DTM and the newly estimated water level values, we have evaluated about 21.7 106 of m3 the water volume loss of the Albano lake from 1993 to 2007, with an average rate of about 1.6 106 m3/yr. © 2008, de Gruyter. All rights reserved

Normal fault earthquakes or graviquakes

Earthquakes are dissipation of energy throughout elastic waves. Canonically is the elastic energy accumulated during the interseismic period. However, in crustal extensional settings, gravity is the main energy source for hangingwall fault collapsing. Gravitational potential is about 100 times larger than the observed magnitude, far more than enough to explain the earthquake. Therefore, normal faults have a different mechanism of energy accumulation and dissipation (graviquakes) with respect to other tectonic settings (strike-slip and contractional), where elastic energy allows motion even against gravity. The bigger the involved volume, the larger is their magnitude. The steeper the normal fault, the larger is the vertical displacement and the larger is the seismic energy released. Normal faults activate preferentially at about 60° but they can be shallower in low friction rocks. In low static friction rocks, the fault may partly creep dissipating gravitational energy without releasing great amount of seismic energy. The maximum volume involved by graviquakes is smaller than the other tectonic settings, being the activated fault at most about three times the hypocentre depth, explaining their higher b-value and the lower magnitude of the largest recorded events. Having different phenomenology, graviquakes show peculiar precursor