86,925 research outputs found
Preface, CEUR Workshop Proceedings, 2024
No full textITASEC24 is the 8th Edition of the Italian conference on Cybersecurity, which is an annual event supported and organized by the CINI Cybersecurity National Lab, and also backed by the Italy’s Agency for National Cybersecurity (ACN). As in previous editions, ITASEC24 includes a Scientific and Technical (S&T) Track whose purpose is to gather Italian researchers, policy, industry, and society working in the field of Cybersecurity. It is thought as a forum to meet, discuss, and exchange experiences among people coming from academy and industry who are interested in cybersecurity and all its applications
A New Actor-Based Structure for Distributed Systems
No full textIn this paper we propose a formal analytic graph- based description of zz-structures, an unusual, graphic-centric way of linking and organizing information. Starting from this formalized model, we make active and operative all the enti- ties of the system, obtaining an actor-based model, called AZ. The actors are organized in different hierarchical levels and cooperate in order to achieve common goals and solve prob- lems. In particular, the use of actor-based technology is helpful in enhancing distributed computing capabilities, and interop- erability in grid systems. The combination of zz-structures and of cooperation activities of different actor classes allows us to define dynamic virtual organizations and to analyze some of issues related to system topological evolutions
A state of art survey on zz-structures
No full textZz-structures are particular data structures capable of representing both hypertextual information and contextual interconnections among different information. The focus of this paper is to stimulate new research on this topic, by providing, in a state of the art survey, a short description and comparison of all the material that, to the best of our knowledge, is related to zz-structures: informal and formal descriptions, implementations, languages, demonstrations, projects and applitudes of zz-structures; in fact, despite their large use in different fields, the literature lacks of an exhaustive and up-to-date description of them
Three-level logic minimization based on function regularities
No full textWe exploit the "regularity" of Boolean functions with the purpose of decreasing the time for constructing minimal three-level expressions, in the sum of pseudoproducts (SPP) form recently developed. The regularity of a Boolean function f of n variables can be expressed by an autosymmetry degree k (with 0 ≤ k ≤ n). k = 0 means no regularity, that is we are not able to provide any advantage over standard synthesis. For k ≥ 1 the function f is said to be autosymmetric, and a new function fk depending on n - k variables only, called the restriction of f, is identified in time polynomial in the number of points of f. The relation between f and fk is discussed in depth to show how a minimal SPP form for f can be build in linear time from a minimal SPP form for fk. The concept of autosymmetry is then extended to functions with don't care conditions, and the SPP minimization technique is duly extended to such functions. A large set of experimental results is presented, showing that 61% of the outputs for the functions in the classical ESPRESSO benchmark suite are autosymmetric. The minimization time for such functions is critically reduced, and cases otherwise intractable are solved. The quality of the corresponding circuits, measured with some well established cost functions, is also improved. Finally, we discuss the role and meaning of autosymmetric functions, and why a great amount of functions of practical interest fall in this class
A formal description of zz-structures
No full textThe focus of this paper is on particular and innovative structures for storing, linking and manipulating information: The zz-structures. In the last years, we worked at the formalization of these structures, retaining that the description of the formal aspects can provide a better understanding of them, and can also stimulate new ideas, projects and research. This work presents our contribution for a deeper discussion on zz-structures
APPROXIMATE MATCHING FOR 2 FAMILIES OF TREES
No full textAbstractWe study approximate matching between h-ary trees (ordered trees whose nodes have exactly h sons) and ordered arbitrary trees, using a string representation of trees. For two h-ary trees P, T, the subtree distance is the number of subtrees to be inserted in P in place of empty nodes, or to be deleted from P, to obtain T. We consider the problem of finding all the occurrences of P in T, with bounded distance k. A known sequential solution requires O(h|P| + h|T| + k|T|) time. We show that the problem can be solved in O(log h + log|P| + log|T| + k) parallel time, in a CRCW-PRAM with O(h(|P| + |T|)) processors. For arbitrary ordered trees we solve a version of the classical tree pattern matching problem. We define the leaf distance between two trees P, T as the total number of subtrees to be inserted in P in place of its leaves, or to be deleted from P leaving leaves in their place, to obtain T. We show how all the occurrences of P as a subtree of T, with bounded distance k, can be determined in O(|P| + k|T|) sequential time, and in O(log|P| + log|T| + k) parallel time in a CRCW-PRAM with O(|P| + |T|) processors. We also discuss an extension of the above problems to labelled trees
Algorithms, nymphs, and shepherds
No full textAbstractComputability and complexity are the two major lines along which the science of algorithms has evolved; but the same concepts guide many human activities. We try to catch some glimpses of the connections between these two worlds, to meet the expectations of the audience. We will encounter nymphs and universal Turing Machines, ancient traditions and randomized procedures, all tending to the same end: having fun with algorithms
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