180,582 research outputs found
A Compositional Semantics for Logic Programs
No full textAbstractThis paper considers open logic programs originally as a tool to build an OR-compositional semantics of logic programs. We extend the original semantic definitions in the framework of the general approach to the semantics of logic programs described by Gabbrielli and Levi (1991). We first define an operational semantics OΩ(P) which models computed answer substitutions and which is compositional w.r.t. the union of programs. Next, we consider the semantic domain of Ω-denotations, which are sets of clauses with a suitable equivalence relation. The fixpoint semantics FΩ(P) given by Bossi and Menegus (1991) is proved equivalent to the operational semantics. From the model-theoretic viewpoint, an Ω-denotation is mapped onto a set of Herbrand interpretations, thus leading to a definition of an Ω-model based on the classical notion of truth. Moreover, we consider a particular kind of Ω-models (compositional models), and we show that OΩ(P) is a (nonminimal) compositional Ω-model. A suitable abstraction of OΩ(P) is compositional and fully abstract w.r.t. the equivalence induced by successful derivations. Finally, some applications of our semantics are discussed. In particular, OΩ(P) can be viewed as the foundations of modular program analysis
Genius loci e locus Sancti
No full textIl libro racconta il paesaggio lombardo attraverso lo sguardo dei santi con una selezione di circa 1000 immagini raccolte per il progetto di fotografia partecipata Tra cielo e terra dell’artista Claudio Beorchia per il Museo di Fotografia Contemporanea di Cinisello Balsamo. La pubblicazione cita le più classiche tra le edizioni – messale, guida Touring Club Italiano, dizionario – riproponendo in 700 pagine migliaia di immagini tra tavole a colori stampate a tutta pagina e miniature in bianco e nero, oltre a un indice generale che riporta i dati delle 2911 edicole fotografate. Le oltre 200 tavole che aprono il libro, presentano in modo sintetico e rarefatto, fedele al concetto originario della ricerca, il puro sguardo dei santi, in soggettiva, grazie alla sagoma dell’immagine ricalcata esattamente sulla forma dell’edicola da cui la figura si sporge verso l’ambiente circostante.Una selezione di circa 800 miniature in bianco e nero, che mettono direttamente in relazione le immagini dei santi e il loro sguardo, è ordinata attraverso dieci tassonomie. Il volume presenta testi bilingui della Presidente del Museo Giovanna Calvenzi, di Claudio Beorchia e Matteo Balduzzi, oltre a contributi critici di Don Umberto Bordoni, responsabile della committenza artistica per l’Arcidiocesi di Milano e di Paolo Bossi, professore associato di Storia dell’architettura al Politecnico di Milano.The book shows the Lombard landscape through the gaze of the saints in votive niches, with a selection of about 1000 images collected on the occasion of the photography project Between heaven and earth by artist Claudio Beorchia for the Museum of Contemporary Photography of Cinisello Balsamo. The publication takes inspiration from classic editions such as the missal, Italian Touring Club guide, the dictionary, collecting in 700 pages thousands of images including full-color printed photographs and black and white miniatures, as well as a general index that shows the data of the 2911 niches photographed. The first section of the book collects more than 200 photographs and shows what the saints see from their positions in a subjective way, thanks to the shape of the image traced exactly on the shape of the niche from which the figure is protruding towards the surrounding environment. A selection of about 800 black and white miniatures, which directly relate the images of the saints and their gaze, is ordered through ten taxonomies. Texts by: Giovanna Calvenzi, Claudio Beorchia, Matteo Balduzzi, Don Umberto Bordoni, Paolo Bossi
A sua Altezza Serenissima il Sig. Principe di Metternich, I. R. Cancelliere di Stato, Cavaliere del Toson D'Oro EC. A Vienna
No full text[G. M. Bossi
Blue Shifted emission from a Pt complex with an expanded pi-system
No full textLuminescent square planar platinum complexes have been extensively studied in medicinal chemistry, photosensitizers and optoelectronic devices. The research in organic light-emitting display (OLED) has attracted much attention because of their high internal efficiency allowing the use of all of the electrogenerated singlet and triplet excitons. In this comunication we report the synthesis of a cyclometallated Pt(II)dibenzoquinoline, (DBQ)Pt(dpm), which has an expanded ligand's pi-system. The comparison of the series of complexes (ppy)Pt(dpm), (BZQ)Pt(dpm),(DBQ)Pt(dpm) and the corresponding free corresponding cyclometallated ligands will be discussed in terms of: X-ray crystallography, electrochemical and photophisical properties and DFT calculations. The unexpected blue shifted emission of (DBQ)Pt(dpm) qualifies it as an interesting phosphorescent dopant for OLEDs. Standard OLED devices were therefore fabricated and studied as well
HAZARD ASSESSMENT OF A POTENTIAL ROCK AVALANCHE IN SOUTH TYROL, ITALY: 3D MODELING AND RISK SCENARIOS
No full textA large DSGDS (Deep-Seated Gravitational Slope Deformation) which extends on an area of 3.75 km2affects the southwest flank of Mount Ganderberg some 40 km north of Bolzano. The gravitational sagging of the slope is generating a wide field of tension cracks in the crown area where a rock slab of about 800.000 m3shows clear precursory signs of possible detachment. In 1401 a rock avalanche detaching from the same area dammed the Passer River thus creating a 35 m deep lake which through sequential breaching caused many casualties in the villages downstream. Using geomorphological survey and historical analysis it was possible to estimate the volume of the landslide deposit in 2 × 106m3. In this study the historical event is back-analyzed using the 2D code DAN-W in order to select the proper soil parameters to use in the modelling of the present potential rock avalanche. Then a 3D modelling is carried out using DAN3D software to evaluate the run-out scenario and the shape of the natural dam. Owing to the relevant discharge of the Passer River, a 2 × 106m3lake might be quickly filled. This can cause the breaching and subsequent collapse of the landslide dam with great risk and potentially heavy damages for the downstream populatio
Simulation of thermal plant optimization and hydraulic aspects of thermal distribution loops for large campuses
No full textFollowing an introduction, the author describes Texas A&M University and its utilities system. After that, the author presents how to construct simulation models for chilled water and heating hot water distribution systems. The simulation model was used in a $2.3 million Ross Street chilled water pipe replacement project at Texas A&M University. A second project conducted at the University of Texas at San Antonio was used as an example to demonstrate how to identify and design an optimal distribution system by using a simulation model. The author found that the minor losses of these closed loop thermal distribution systems are significantly higher than potable water distribution systems. In the second part of the report, the author presents the latest development of software called the Plant Optimization Program, which can simulate cogeneration plant operation, estimate its operation cost and provide optimized operation suggestions. The author also developed detailed simulation models for a gas turbine and heat recovery steam generator and identified significant potential savings. Finally, the author also used a steam turbine as an example to present a multi-regression method on constructing simulation models by using basic statistics and optimization algorithms. This report presents a survey of the author??s working experience at the Energy Systems Laboratory (ESL) at Texas A&M University during the period of January 2002 through March 2004. The purpose of the above work was to allow the author to become familiar with the practice of engineering. The result is that the author knows how to complete a project from start to finish and understands how both technical and nontechnical aspects of a project need to be considered in order to ensure a quality deliverable and bring a project to successful completion. This report concludes that the objectives of the internship were successfully accomplished and that the requirements for the degree of Degree of Engineering have been satisfied
Norms on Terms and their use in Proving Universal Termination of a Logic Program
No full textAbstractIn this paper semi-linear norms, a class of functions to weight the terms occurring in a program, are defined and studied. All the functions in this class have the nice property of allowing a syntactical characterization of rigid terms, i.e. terms whose weight does not change under substitution. Based on these norms, a general proof method for universal termination of pure Prolog programs can be adapted to deal with a large class of programs in a simple way. The proof method requires pre/post specifications well-behaved with respect to substitutions to be associated with each predicate symbol in the program, and ordering functions not increasing with respect to substitutions to be associated with cycles in the program. The specification collects information on term properties which are useful to prove that the ordering functions actually decrease at each traversal of each cycle. Some examples of termination proof are also given
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