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Gap functions and penalization for solving equilibrium problems with nonlinear constraints
No full textThe paper deals with equilibrium problems (EPs) with nonlinear convex constraints. First, EP is reformulated as a global optimization problem introducing a class of gap functions, in which the feasible set of EP is replaced by a polyhedral approximation. Then, an algorithm is given for solving EP through a descent type procedure related to exact penalties of the gap functions and its global convergence is proved. Finally, the algorithm is tested on a network oligopoly problem with nonlinear congestion constraints<br /
QoS-control of Structured Parallel Computations: a Predictive Control Approach
No full textA central issue for parallel applications executed on heterogeneous distributed platforms (e.g. Grids and Clouds) is assuring that performance and cost parameters are optimized throughout the execution. A solution is based on providing application components with adaptation strategies able to select at run-time the best component configuration. In this report we will introduce a preliminary work concerning the exploitation of control-theoretic techniques for controlling the Quality of Service of parallel computations. In particular we will demonstrate how the model-based predictive control strategy can be used based on first-principle performance models of structured parallelism schemes. We will also evaluate the viability of our approach on a first experimental scenario.<br /
Il giardino-città della Scarzuola di Tomaso Buzzi
Full text linkNella seconda metà del secolo scorso, l’architetto milanese Tomaso Buzzi (1900-1981), dà vita, nel
giardino della Scarzuola (a Montegiove, in provincia di Terni), a un’opera assolutamente originale: di fianco
alle architetture dell’antico convento francescano, crea una sua personale città teatrale, un giardino
ermetico-iniziatico, sul modello dell’Hypnerotomachia Poliphili di Francesco Colonna, con uno sguardo
alla Sforzinda di Filarete e ai complessi di Bomarzo da un lato e del Vittoriale dannunziano dall'altro.
Difficile comprendere le motivazioni che possono aver portato un architetto immerso nella committenza
aristocratico-mondana come Buzzi, a intraprendere un’opera tanto complessa quanto personale e
interiore come la Scarzuola, luogo privato di rifugio e di piacere. Infatti negli scritti e appunti che lo stesso
architetto ha lasciato, niente autorizza a darne un’unica, chiara ed univoca interpretazione; frattanto,
il cantiere continua ancora a crescere e fondersi con il suo ambiente naturale, grazie a Marco Solari, che
si impegna a conservare e terminare l'opera, basandosi sugli schizzi dello zio.
Il presente articolo descrive il percorso del giardino (che si snoda a cominciare dal vecchio hortus
conclusus dei frati del convento, fino a coinvolgere tutta la vallata adiacente) e alcuni significati degli
innumerevoli simboli e architetture che si incontrano (e disorientano) lungo il cammino.
Fra tutte le definizioni attribuite alla Scarzuola, ciò che forse meglio la descrive è quella di un sogno,
della rappresentazione dell’interiorità dell’architetto, dell’altro suo ‘io’, svelato in modo libero da ogni
imposizione di quegli ambienti ufficiali nei quali, ad un certo punto della sua vita, non si riconosceva
più. Una opportunità per essere se stesso, raccogliendo tutte le esperienze passate e affidandole alla
memoria nella “pietrificazione” delle proprie idee.
In the second half of last century, the Italian architect Tomaso Buzzi (1900-1981), built, in the garden
of Scarzuola (Montegiove, in the province of Terni), a highly original work: beside the ancient Franciscan
monastery, he created theatrical city of his own, a hermetic garden with the aim of a superior initiation.
He followed as a model the Hypnerotomachia Poliphili by Francesco Colonna, with a look at Filarete's
Sforzinda and to such complexes as Bomarzo garden on the one hand and the Vittoriale on the other.
It's very difficult to understand the motivations that may have brought an architect as Buzzi, involved
in aristocratic patronage, to make such a complex and spiritual work as the Scarzuola, a private place of
refuge and pleasure. In fact in the writings and notes that the same architect has left, nothing allows to
give a single, unambiguous interpretation. Meanwhile, the site continues to grow into its natural environment,
thanks to Marco Solari, who is committed to finish the work, based on his uncle's sketches.
This article describes the path of the garden (which runs between the old hortus conclusus of the
friars, and the adjacent valley) and some of the meanings of symbols and architectures that we meet.
Among all the definitions attributed to Scarzuola, the one that perhaps best describes it is...a dream,
the representation of the architect's interior life, his alter ego, freely revealed , an opportunity to be himself,
picking up all his past experiences and fixing them in the "petrification" of his own ideas
Angiolo Mazzoni del Grande nell’archivio MOPT in Colombia (1948-1963)
No full textFrom 1947 to 1960 the activities of Angelo Mazzoni Del Grande, Italian engineer of the Ministry of Transport, was very intense in Colombia The paper illustrates the architecture projects by Angelo Mazzoni Del Grande deposited in the archive MOPT (Ministerio Obras Publicas y Transporte) of Bogota. The archive contains some drawings of buildings built in Bogota and other cities of Colombia.
The Colombian experience was very productive but currently few architectures are still in use and well-preserved
Nonabelian Faddeev-Niemi Decomposition of the SU(3) Yang-Mills Theory
No full textFaddeev and Niemi (FN) have introduced an abelian gauge theory which
simulates dynamical abelianization in Yang-Mills theory (YM). It contains both
YM instantons and Wu-Yang monopoles and appears to be able to describe the
confining phase. Motivated by the meson degeneracy problem in dynamical
abelianization models, in this note we present a generalization of the FN
theory. We first generalize the Cho connection to dynamical symmetry breaking
pattern SU(N+1) -> U(N), and subsequently try to complete the Faddeev-Niemi
decomposition by keeping the missing degrees of freedom. While it is not
possible to write an on-shell complete FN decomposition, in the case of SU(3)
theory of physical interest we find an off-shell complete decomposition for
SU(3) -> U(2) which amounts to partial gauge fixing, generalizing naturally the
result found by Faddeev and Niemi for the abelian scenario SU(N+1) -> U(1)^N.
We discuss general topological aspects of these breakings, demonstrating for
example that the FN knot solitons never exist when the unbroken gauge symmetry
is nonabelian, and recovering the usual no-go theorems for colored dyons
LA CULTURA DEL RESTAURO IN COLOMBIA NEL SECOLO XX
Full text linkSUMMARY The culture of the restauration in Colombia represents an interesting reality and in continuous progress and growth. From 1918, with the institution of the Dirección Nacional de Bellas Artes begins a normative and cultural run. Also near the Universities and particularly near the Pontifical Universidad Javeriana are been founded courses of restauration and history of the architecture. The contribution furnishes a description of this cultural development in Colombia for the protection of the Cultural Patrimony. From the 2006 Olimpia Niglio is Visiting Profesor in Architectural Restauration for Universidad de Ibagué, Colombia
Visione artificiale nell'industria conciaria
No full textLe potenzialità di applicazione dei sistemi di visione artificiale in ambito conciario.
Potential of automated visual inspection in the leather industr
Preventing the collision of requests from slave clocks in the Precision Time Protocol (PTP)
No full textSUMMARY The Precision Time Protocol (PTP) distributes a time reference across a network: it specifically addresses demanding environments, where it can reach sub microsecond precision using appropriate technologies. Its scalability is primarily limited by packet delay variations induced by packet collisions. While it is possible to avoid collisions with non-PTP packets using traffic management technologies, collision between PTP packets is an open problem in large systems with critical clock precision requirements. We propose a coordination algorithm that avoids the occurrence of such collisions. It assumes that the timing reference source, the master clock, can send a packet in multicast to the slaves: this is not a restrictive hypotesis, since PTP itself takes advantage of this kind of connectivity, and it is also compatible with typical wireless environments. The algorithm operates without introducing additional traffic, it ensures an upper bound to the time between two successive synchronizations of any given slave, it does not alter the structure of the standard PTP messages, it envisions a dynamic number of slaves, it tolerates the replacement of the master with a hot spare in case of failure, and does not rely on specialized hardware. The algorithm has a footprint that does not insist on activities that are already time sensitive, and its operation is mostly concentrated on the master. The algorithm inherits security and fault tolerance limits from PTP: in particular this refers to malicious nodes, and to broken devices that may jam the network
A formal specification of the semantics of ECMAScript
No full textWeb applications (i.e., applications whose interface is presented to the user via a web browser, whose state is split between a server and a client, and where the only interaction between server and client is through the HTTP protocol) are become more and more widespread, and integrated in most users' everyday work habits. The glue linking the desperate technologies involved, from dynamic HTML to XML RPC, is the Javascript language. Yet, no formal definition of its semantics exists, which in turn makes it impossible to formally prove correctness, liveness and security properties of Web applications. As a first step towards improving this situation, we provide a formal semantics for ECMAScript (standard ECMA-262), by means of an Abstract State Machines (ASMs) specification. We follow the path established by other specification efforts for similar languages (e.g. Java and C#), but in addition we establish a formal trace between parts of our specification and the ECMA standard, thus facilitating the proof of correctness of the specification. More specifically, we define the dynamic semantics of ECMAScript by providing (in terms of ASMs) an interpreter which executes ECMAScript programs. We use an algebra to represent the state of the ECMAScript program, the state of the ECMAScript interpreter, and the state of the host environment (typically, the browser). We assume the necessary syntactic information (namely, the annotated Abstract Syntax Tree (AST) of the given program) to be available. Using ASM we detail a visit of the AST, whose effect is to simulate the execution of the program. In the ECMA standard the behavior of ECMAScript constructs is operationally described using so-called abstract operations (AO), coming as numbered lists of steps. Therefore our interpreter is composed out of two submachines: ECMA-Script and ECMA-AO interpreters. The former invokes the ECMA-AO one to evaluate nodes, simulating AOs used in ECMA standard to describe the production's semantics. We organize the ECMA-AO interpreter rules in such a way that each rule application corresponds to an AO instruction in the ECMA standard. This helps to check the correctness of the ASM model wrt the ECMA standard as well as the correctness of implementations wrt ASM model. Therefore, the state of our interpreter can be mapped via abstraction/refinement functions onto the concrete state of any comformant implementation
Programming the KDD process using XQuery
No full textXQuake is a language and system for programming data mining processes over native XML databases in the spirit of inductive databases. It extends XQuery to support KDD tasks. This paper focuses on the features required in the definition of the steps of the mining process. The main objective is to show the expressiveness of the language in handling mining operations as an extension of basic XQuery expressions. To this purpose, the paper offers an extended application in the field of analyzing web logs.<br /