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101.
Paolo Bottoni 《Electronic Notes in Theoretical Computer Science》2003,82(7):120-132
A large class of diagrammatic languages falls under the broad definition of “executable graphics”, meaning that some transformational semantics can be devised for them. On the other hand, the definition of static aspects of visual languages often relies on some form of parsing or constructive process. We propose here an approach to the definition of visual languages syntax and semantics based on a notion of transition as production/consumption of resources. Transitions can be represented in forms which are intrinsic to the diagrams or external to them. A collection of abstract metamodels is presented to discuss the approach. 相似文献
102.
In this paper, fast recursive algorithms for the approximation of an n-dimensional convex polytope by means of an inscribed ellipsoid are presented. These algorithms consider at each step a single inequality describing the polytope and, under mild assumptions, they are guaranteed to converge in a finite number of steps. For their recursive nature, the proposed algorithms are better suited to treat a quite large number of constraints than standard off-line solutions, and have their natural application to problems where the set of constraints is iteratively updated, as on-line estimation problems, nonlinear convex optimization procedures and set membership identification. 相似文献
103.
Test management aims at organizing, documenting and executing test cases, and at generating execution reports. The adoption of a support tool and of a standard process for such activities is expected to improve the current practice. ITALO is a European project devoted to the evaluation of the benefits coming from test management automation. In this paper the experiences collected and the lessons learned during ITALO are summarized. A formal methodology was adopted for the selection of a support tool among those available from the market. A survey of the current practice in component testing was conducted to adapt the existing process model so as to obtain the greatest benefits from automation. An empirical study was then designed to measure the effects that are expected to be produced by the new test process complemented with the introduction of the support tool. Three pilot projects were conducted to measure the benefits obtained from tool usage and process modification. Results are presented and discussed in this paper. 相似文献
104.
Anna Ciampolini Evelina Lamma Paola Mello Francesca Toni Paolo Torroni 《Annals of Mathematics and Artificial Intelligence》2003,37(1-2):65-91
This paper presents ALIAS, an agent architecture based on intelligent logic agents, where the main form of agent reasoning is abduction. The system is particularly suited for solving problems where knowledge is incomplete, where agents may need to make reasonable hypotheses about the problem domain and other agents, and where the raised hypotheses have to be consistent for the overall set of agents. ALIAS agents are pro-active, exhibiting a goal-directed behavior, and autonomous, since each one can solve problems using its own private knowledge base. ALIAS agents are also social, because they are able to interact with other agents, in order to cooperatively solve problems. The coordination mechanisms are modeled by means of LAILA, a logic-based language which allows to express intra-agent reasoning and inter-agent coordination. As an application, we show how LAILA can be used to implement inter-agent dialogues, e.g., for negotiation. In particular, LAILA is well-suited to coordinate the process of negotiation aimed at exchanging resources between agents, thus allowing them to execute the plans to achieve their goals. 相似文献
105.
Tropos: An Agent-Oriented Software Development Methodology 总被引:16,自引:4,他引:16
Paolo Bresciani Anna Perini Paolo Giorgini Fausto Giunchiglia John Mylopoulos 《Autonomous Agents and Multi-Agent Systems》2004,8(3):203-236
Our goal in this paper is to introduce and motivate a methodology, called Tropos,1 for building agent oriented software systems. Tropos is based on two key ideas. First, the notion of agent and all related mentalistic notions (for instance goals and plans) are used in all phases of software development, from early analysis down to the actual implementation. Second, Tropos covers also the very early phases of requirements analysis, thus allowing for a deeper understanding of the environment where the software must operate, and of the kind of interactions that should occur between software and human agents. The methodology is illustrated with the help of a case study. The Tropos language for conceptual modeling is formalized in a metamodel described with a set of UML class diagrams. 相似文献
106.
Marco Alberti Marco Gavanelli Evelina Lamma Paola Mello Paolo Torroni 《Electronic Notes in Theoretical Computer Science》2004,85(2):94
In this paper we propose a logic-based social approach to the specification and verification of agent interaction. We firstly introduce integrity constraints about social acts (called Social Integrity Constraints) as a formalism to express interaction protocols and to give a social semantics to the behavior of agents, focusing on communicative acts. Then, we discuss several possible kinds of verification of agent interaction, and we show how social integrity constraints can be used to verify some properties in this respect. We focus our attention on static verification of compliance of agent specifications to interaction protocols, and on run-time verification, based on agents' observable behavior. We adopt as a running example the NetBill security transaction protocol for the selling and delivery of information goods. 相似文献
107.
Pier Paolo Civalleri Marco Gilli 《International Journal of Circuit Theory and Applications》2004,32(6):609-614
The state equations of open two‐level quantum systems, which form the building blocks of quantum cellular neural networks, are studied in arbitrary representations. It is shown that the dissipation matrix, that under the usual assumptions is diagonal in the energy representation, such remains if and only if the coupling between the states induced by an external field is real and infinitesimal. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
108.
Principal Component Analysis (PCA) is a well-known technique, the aim of which is to synthesize huge amounts of numerical data by means of a low number of unobserved variables, called components. In this paper, an extension of PCA to deal with interval valued data is proposed. The method, called Midpoint Radius Principal Component Analysis (MR-PCA), recovers the underlying structure of interval valued data by using both the midpoints (or centers) and the radii (a measure of the interval width) information. In order to analyze how MR-PCA works, the results of a simulation study and two applications on chemical data are proposed. 相似文献
109.
J-integral has been calculated along the free-of-stress border of deep and shallow rounded notches under torsion, under the hypothesis of a linear elastic behaviour of the material. Two exact closed-form solutions have been obtained which make it explicit the influence of the notch opening angle and the notch root radius. When the notch root radius tends to zero the proposed solution matches the expression for the corresponding pointed V-notch case. 相似文献
110.
Paolo Gronchi Roberto Canziani Andrea Brenna Simone Visigalli Carles Colominas Francesc Montalà 《Materials and Manufacturing Processes》2017,32(11):1265-1273
The sewage sludge dewatering produced by wastewater treatment plants (WWTP) is a multifaceted process due to the presence of colloid fractions. Electro-osmosis could be a suitable technique to reduce the water content of the final sludge. Electric fields of 10, 15, and 20?V/cm have been studied for electro-osmosis tests under the pressure of a static or rotating piston, obtaining a dry solids content up to 40–45%, with respect to 25–30% obtained by mechanical methods. In order to optimize the process, the corrosion behavior and the wear of the anodic material appear to be the main critical aspects, due to the high circulating current density and the use of a rotating electrode. We compared the efficiency and the corrosion resistance of dimensionally stable anodes (DSA) with respect to bare stainless steel (AISI 304) and stainless steel coated by PVD technique with TiN, AlTiN, and DLC. Characterization of the anode surfaces by SEM and potentiodynamic tests show that DSA is the most suitable material for our application. However, efficiencies of the electro-osmosis processes have been found comparable, in terms of developed current densities and total energy consumptions, for short-test duration. 相似文献