Between quantum logic and concurrency

We start from two closure operators defined on the elements of a special kind of partially ordered sets, called causal nets. Causal nets are used to model histories of concurrent processes, recording occurrences of local states and of events. If every maximal chain (line) of such a partially ordered set meets every maximal antichain (cut), then the two closure operators coincide, and generate a complete orthomodular lattice. In this paper we recall that, for any closed set in this lattice, every line meets either it or its orthocomplement in the lattice, and show that to any line, a two-valued state on the lattice can be associated. Starting from this result, we delineate a logical language whose formulas are interpreted over closed sets of a causal net, where every line induces an assignment of truth values to formulas. The resulting logic is non-classical; we show that maximal antichains in a causal net are associated to Boolean (hence "classical") substructures of the overall quantum logic.Comment: In Proceedings QPL 2012, arXiv:1407.842

The Synthesis Problem for Elementary Net Systems is NP-Complete

The so-called synthesis problem consists in deciding for a class of nets whether a given graph is isomorphic to the case graph of some net and then constructing the net. This problem has been solved for various classes of nets, ranging from elementary nets to Petri nets. The general principle is to compute regions in the graph, i.e. subsets of nodes liable to represent extensions of places of an associated net. The naive method of synthesis which relies on this principle leads to exponential algorithms for an arbitrary class of nets. In an earlier study, we gave algorithms that solve the synthesis problem in polynomial time for the class of bounded Petri nets. We show here that in contrast the synthesis problem is indeed NP-complete for the class of elementary nets. This result is independent from the results of Kunihiko Hiraishi, showing that both problems of separation and inhibition by regions at a given node of the graph are NP-complete

Orthomodular Lattices Induced by the Concurrency Relation

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Polynomial Algorithms for the Synthesis of Bounded Nets

The so-called synthesis problem for nets, which consists in deciding whether a given graph is isomorphic to the case graph of some net, and then constructing the net, has been solved in the litterature for various types of nets, ranging from elementary nets to Petri nets. The common principle for the synthesis is the idea of regions in graphs, representing possible extensions of places in nets. However, no practical algorithm has been defined so far for the synthesis. We give here explicit algorithms solving in polynomial time the synthesis problem for bounded nets from regular languages or from finite automata

Le divisioni in seno all’aristocrazia milanese del XII secolo: le cause politiche dell’emarginazione di un ramo dei capitanei de Raude a partire da un documento del 1137

The history of Milan between 1128 and 1145 shows deep changes in the configuration of city’s political space; these changes led to the formation of the consular government. however, this period was an age of deep discord in the city’s society. The political struggle was focused in the contrast between two partes; the struggle between these two local groups overlapped the conflict between Conrad of Swabia and Lothair of Supplinburg for the imperial crown (1125-1135). This conflict had consequences on the family structures of the Milanese élites. Indeed, a document dated to 1137 shows the strong contrasts and divisions that the political struggles had on one of the most important families of the Milanese aristocracy: the capitanei de Raude. Keywords: Milano, Secolo XII ineunte, Lotte politiche, Divisioni famigliari, Aristocrazia Milan, First half of 12th century, Political struggle, Family discords, Aristocracy

Terminology validation for MT output

WebTerm Connector is a plugin for STAR MT Translate which combines machine translation with validated terminology information. The aim is to provide “understandable” information in the target language using corporate language and terminology

Innovative Minichannel Condensers and Evaporators for Air Conditioning Equipment

The use of aluminum heat exchangers for refrigeration and air-conditioning equipment is very interesting since it allows to reduce weight and manufacturing costs while maintaining high performance. In this paper a two-phase heat transfer characterization of an innovative aluminum minichannel heat exchanger is presented. The heat exchanger (HX) is composed by rectangular channels with internal perforated turbolators. A special test section has been projected and realized in the Two Phase Heat Transfer Lab of the University of Padova in order to measure the heat transfer coefficient (HTC) on the refrigerant side during flow boiling and condensation. The test section has a single refrigerant channel with a perforated fin to make the minichannels. The test section is provided with 14 water flow modules installed at top and bottom of the refrigerant channel to promote boiling or condensation of the refrigerant. Therefore, the test section is made of seven different zones: each of them is equipped with 8 thermocouples to measure the wall temperature during the refrigerant phase change. The heat flow rate in each zone is calculated by an energy balance on the water side. Pressure transducers and thermocouples on the refrigerant side allow to determine the saturation temperature and thus the heat transfer coefficient of the refrigerant. The operating refrigerant used during tests is R410A. The particular scheme adopted for the test section enables to measure HTC at varying vapor quality and heat flow rate. Vaporization and condensation tests were carried out with different saturation temperatures, specific heat flow rate (from 40 to 150 kW/m2) and refrigerant mass flux (50÷150 kg/(m2 s) ). Data acquired have been compared with vaporization and condensation predictions from various correlations available in literature. This part of the work is very interesting since no data is available in the literature for such a geometry in vaporization nor in condensation. Therefore, the present paper will investigate the potential performance of these innovative minichannel heat exchangers as condensers and evaporators in air-conditioning equipment

The 12th Century Milanese Aristocracy Inner Divisions: the Political Causes of the Marginalisation of a capitanei de Raude Branch, Moving from a 1137 Document

The history of Milan between 1128 and 1145 shows deep changes in the configuration of city’s political space; these changes led to the formation of the consular government. however, this period was an age of deep discord in the city’s society. The political struggle was focused in the contrast between two partes; the struggle between these two local groups overlapped the conflict between Conrad of Swabia and Lothair of Supplinburg for the imperial crown (1125-1135). This conflict had consequences on the family structures of the Milanese élites. Indeed, a document dated to 1137 shows the strong contrasts and divisions that the political struggles had on one of the most important families of the Milanese aristocracy: the capitanei de Raude.La storia di Milano tra il 1128 e il 1145 vide profondi cambiamenti nella configurazione dello spazio politico cittadino; queste trasformazioni condussero alla formazione del regime consolare. Tuttavia, furono anche anni di profonde divisioni nella società cittadina. La lotta politica si incentrò nella contrapposizione tra due partes; lo scontro tra gli schieramenti locali si sovrappose al conflitto intercorso tra Corrado di Svevia e Lotario di Supplimburgo per la corona imperiale (1125- 1135). Questa rivalità ebbe conseguenze, ancora poco studiate, sulle strutture famigliari dell’élite cittadina. Infatti, un documento del 1137 testimonia i forti contrasti e le divisioni che le lotte politiche ebbero su una delle famiglie più importanti dell’aristocrazia milanese: i capitanei de Raude