177,674 research outputs found
PIGNATELLI ARAGONA CORTÉS E MENDOZA, Diego
No full textProfilo biografico di Diego Pignatelli Aragona Cortes, principe di Castelvetrano (1687-1750)Biographical profile of Diego Pignatelli Aragona Cortes, prince of Castelvetrano (1687-1750
Normal form in hecke-kiselman monoids associated with simple oriented graphs
No full textGeneralizziamo il concetto, introdotto da Kudryavtseva e Mazorchuk, di forma canonica di un elemento [9] nel semigruppo di Kiselman al contesto di un monoide di Hecke-Kiselman HKΓ associato ad un grafo orientato semplice Γ. Usiamo proprietà di confluenza da [7] per associare a ogni elemento di HKΓ una forma normale; tali forme normali non sono uniche e mostriamo che possono essere ottenute l'una dall'altra attraverso una successione di commutazioni elementari. Descriviamo infine una procedura generale per ottenere una forma normale lessicograficamente minimale (unica).We generalize Kudryavtseva and Mazorchuk’s concept of a canonical form of elements [9] in Kiselman’s semigroups to the setting of a Hecke-Kiselman monoid HKΓ associated with a simple oriented graph Γ. We use confluence properties from [7] to associate with each element in HKΓ a normal form; normal forms are not unique, and we show that they can be obtained from each other by a sequence of elementary commutations. We finally describe a general procedure to recover a (unique) lexicographically minimal normal form
Semi-invariants of symmetric quivers
No full textL'obiettivo della tesi è descrivere l'anello dei semi-invarianti di quiver simmetrici di tipo finito e di tipo tame. Nella prima parte dimostriamo risultati generali riguardanti i semi-invarinti di quiver simmetrici. Poi enunciamo e dimostriamo il teorema centrale in cui esibiamo un insieme di generatori dell'anello dei semi-invarianti di quiver simmetrici di tipo finito e di tipo tame. Congetturiamo vero infine questo teorema per qualsiasi quiver simmetrico.The goal of the thesis is to describe the ring of semi-invariants for symmetric quivers of finite and tame type. First, we prove general results about semi-invariants of symmetric quivers. Next, we state and prove the main theorem where we display a set of generators of the ring of semi-invariants for symmetric quivers of finite and tame type. Finally, we conjecture true this theorem for any symmetric quivers
Hecke-Kiselman monoids of small cardinality
No full textIn this paper, we give a characterization of digraphs Q, {pipe}Q{pipe}≤4 such that the associated Hecke-Kiselman monoids HQ are finite. In general, a necessary condition for HQ to be a finite monoid is that Q is acyclic and its Coxeter components are Dynkin diagrams. We show, by constructing examples, that such conditions are not sufficient. © 2012 Springer Science+Business Media, LLC
Open science and the academic profession
No full textOpen science is considered a new science paradigm to make research accessible, accountable, and effective. Open science is already changing the academic profession starting from micro-practices to professional relations with epistemic communities and stakeholders, with implications that we are not yet able to predict. The article delves first into literature and official documentation to unfold the discursive regimes which sustain the spread of open science. A specific focus is then devoted to the professional transition, highlighting the role of funding organizations in setting the new science environment and the subjective experience of academics. The article is completed by a case study in the field of Research Data Management where the misalignment among incumbent/changing processes can be more apparent. Finally, a research agenda that focuses on how academic micro-practices are affecting organizations and science structures is proposed. This article aims at beginning to plow the ground for new research directions to emerge
Some group-theoretical results on Feistel Networks in a long-key scenario
No full textThe study of the trapdoors that can be hidden in a block cipher is and has always been a high-interest topic in symmetric cryptography. In this paper we focus on Feistel-network-like ciphers in a classical long-key scenario and we investigate some conditions which make such a construction immune to the partition-based attack introduced recently by Bannier et al
Several proofs of security for a tokenization algorithm
No full textIn this paper we propose a tokenization algorithm ofReversibleHybrid type, as defined in PCI DSS guidelines for designing a tokenization solution, based on a block cipher with a secret key and (possibly public) additional input. We provide some formal proofs of security for it, which imply our algorithm satisfies themost significant security requirements described in PCI DSS tokenization guidelines. Finally, we give an instantiation with concrete cryptographic primitives and fixed length of the PAN, and we analyze its efficiency and security
An ultimately periodic chain in the integral Lie ring of partitions
No full textGiven an integer n, we introduce the integral Lie ring of partitions with bounded maximal part, whose elements are in one-to-one correspondence to integer partitions with parts in {1,...,n-1}. Starting from an abelian subring, we recursively define a chain of idealizers and we prove that the sequence of ranks of consecutive terms in the chain is ultimately periodic. Moreover, we show that its growth depends of the partial sum of the partial sum of the sequence counting the number of partitions. This work generalizes our previous recent work on the same topic, devoted to the modular case where partitions were allowed to have a bounded number of repetitions of parts in a ring of coefficients of positive characteristic
Technological Innovation and Urban Processes
No full textTechnological innovation pushes transformatioin, rennovation and urban regenaration of areas and services. Special attention is given to the major urban centres, for the most related to nationale and/or Ue policy (Ce, 2003; Ce, 2004). A number of important questions are emerging between the reinforcement of the bigger areas, both metropolitan and urban, and the smaller centres. Moreover, according with different institutional actors it would be better more balanced process of anthropization because environmental and social reasons (APAT, 2004). In Calabria there are very few towns with more then 15.000 residents, often they are isolated and in the internal land. It requires to connect these areas by network, to push the diffusion of innovation and technology, to build up the “educated technology†(Del Nord, 1991). As said in other place (Aragona, 2003), the region is becoming to partecipate to the global village and the Ue (Ue, 1994; 1995; 1996) have policies and areas of implementation (Information Society, POR Calabbria 2000-20006; RIS+ 2001-2002). The paper faces a number of questions continuing such a topic. How are changing some of these areas that have implemented the technological innovation? Which impact are making the strategies and the choices on the spatial, functional and social context. The social effectiveness related to the quality life, said by Gasparini (1990) does it better? Could it be the outcome due to the absence of concentrated localization as is the case of other territorial areas marked by the “reticular†network (Dematteis, 1990)? Above all it requires to evaluate, said that the technological facilities are present enough, the role plays by the innovation as engine for both the cultural and awareness growth. Push for and knowledge that overcomes the mere informatization and suggestes the e-government: a formation and information path dedicated to build up new tools for local action and planning in the global competition. Identification of new settlements and spatial criteria (Appold et al., 1990), construction of urban spaces as signs of the past (Augè, 2004) but also signals of a new development and of social choesion, new citizenship (Cacciari, 1991).
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