1,721,123 research outputs found
Cellular Automata Pseudo-Random Number Generators and Their Resistance to Asynchrony
No full textCellular Automata (CA) have a long history being employed as pseudo-random number generators (PRNG), especially for cryptographic applications such as keystream generation in stream ciphers. Initially starting from the study of rule 30 of elementary CA, multiple rules where the objects of investigation and were shown to be able to pass most of the rigorous statistical tests used to assess the quality of PRNG. In all cases, the CA employed where of the classical, synchronous kind. This assumes a global clock regulating all CA updates which can be a weakness if an attacker is able to tamper it. Here we study how much asynchrony is necessary to make a CA-based PRNG ineffective. We have found that elementary CA are subdivided into three class: (1) there is a “state transition” where, after a certain level of asynchrony, the CA loses the ability to generate strong random sequences, (2) the randomness of the sequences increases with a limited level of asynchrony, or (3) CA normally unable to be used as PRNG exhibit a much stronger ability to generate random sequences when asynchrony is introduced
Enhancing Large Language Models-Based Code Generation by Leveraging Genetic Improvement
Full text linkIn recent years, the rapid advances in neural networks for Natural Language Processing (NLP) have led to the development of Large Language Models (LLMs), able to substantially improve the state-of-the-art in many NLP tasks, such as question answering and text summarization. Among them, one particularly interesting application is automatic code generation based only on the problem description. However, it has been shown that even the most effective LLMs available often fail to produce correct code. To address this issue, we propose an evolutionary-based approach using Genetic Improvement (GI) to improve the code generated by an LLM using a collection of user-provided test cases. Specifically, we employ Grammatical Evolution (GE) using a grammar that we automatically specialize—starting from a general one—for the output of the LLM. We test 25 different problems and 5 different LLMs, showing that the proposed method is able to improve in a statistically significant way the code generated by LLMs. This is a first step in showing that the combination of LLMs and evolutionary techniques can be a fruitful avenue of research
Multi-objective particle swarm optimization for environmental risk/benefit analysis with pre-assignment strategy
No full textHydropower is a fundamental renewable energy source, and the Amazon basin represents one of its largest untapped frontiers. However, its expansion in this ecologically sensitive region raises significant environmental challenges, especially concerning greenhouse gas emissions. In this paper, we develop a multi-objective optimization framework that employs a variant of the Multi-Objective Particle Swarm Optimizer to balance the competing objectives represented by the total electricity generation and the reduction of carbon emissions. We analyse a dataset of 509 dams, categorized by geographical and technical features, to assess the impact of site selection and taking into account the pre-assignment of dams already installed. We further inspect the key features of dams that compose the best configurations to maximize energy output while minimizing emissions. In such configurations, the dams are located in highland areas, offering flexible trade-offs and allowing planners to balance sustainability with energy demands. Decision-makers could take advantage of this work by adopting a strategic approach to hydropower expansion that prioritizes energy efficiency and environmental responsibility, showcasing the effectiveness of computational optimization in sustainable energy planning
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Didattica a Distanza e Online Learning: rischi e opportunità d’innovazione. Un’indagine esplorativa
No full textIl presente contributo discute gli esiti di una ricerca esplorativa condotta con lo scopo di indagare le pratiche dei docenti durante la sospensione delle attività scolastiche in presenza e l’erogazione della formazione online. Per erogare corsi online è necessario possedere skills specifiche che riguardano una varietà di aspetti: dalla competenza digitale, alla consapevolezza che i processi di progettazione e mediazione didattica debbono essere differenti, come anche i metodi adoperati al fine di promuovere apprendimenti significativi e presenza sociale. L’avvio emergenziale della didattica a distanza (DaD) nelle scuole, invece, ha certamente posto la classe docente nella condizione di dover gestire un conte- sto formativo differente senza che vi fosse stata necessariamente una formazione di base adeguata. Lungi dal considerare la DaD una semplice parentesi priva di conseguenze a lungo termine sull’istituzione scolastica, si ritiene, piuttosto, che essa possa porre le basi per un ripensamento consapevole dei modi di fare scuola da cui possano scaturire processi di innovazione
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Reaction Systems Made Simple A Normal Form and a Classification Theorem
No full textReaction systems are models of computation inspired by the interactions between biochemical reactions. We define a notion of multi-step simulation among reaction systems and derive a classification with respect to the amount of resources (reactants and inhibitors) involved in the reactions. We prove that one reactant and one inhibitor per reaction are sufficient to simulate arbitrary systems. Finally, we show that the equivalence relation of mutual simulation induces exactly five linearly ordered classes of reaction systems
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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