1,721,011 research outputs found
Optimization approaches in distributed systems
Full text linkThe necessity of performing multiple complex tasks in short time in a typical Industry 4.0 environment has enlightened the need to improve computational and storage infrastructures and ensure efficient communication between machines in modern manufacturing plants.
Most of these processes are pure digital and can be delivered directly in the Cloud, thus ensuring more resilience and performance. When Cloud resources are delivered in distributed fashion, the global computational effort is spread across all the network, whereas when the process is also decentralized there’s not a single point of decision in system behaviour. As a result, the innate features of distributed and decentralized systems contribute to decreasing the execution time of the tasks and preventing single points of failure in the infrastructure.
Within the scope of these systems, a great variety of optimization problems can be implemented. Some of these problems pertain to classical linear or nonlinear approaches, whereas others to Machine Learning techniques, such as Artificial Neural Networks and Deep Reinforcement Learning (DRL), or Swarm Intelligence algorithms.
The main research direction of this thesis is the implementation of some common optimization problems in distributed systems. In detail, in part I, the application of the task assignment problem in Blockchain-based environments is proposed in a typical manufacturing environment. Two different original architectures, the first in Ethereum and the second in Hyperledger Fabric, are described with the scope of consuming multiple complex digital processes, such as data mining problems, heavy file format conversion, and 3D rendering, in a parallel fashion in multi agent environments.
In both proposed architectures, task delivery is orchestrated by a Smart Contract. The main goal is to find the agent that executes the required task in least time. To this end, a task runtime prediction algorithm is designed by the means of an Artificial Neural Network in the first case and a Deep Reinforcement Learning algorithm in the second case. While in the first case, the main contribution is the combined use of Blockchain with some popular cloud technologies, such as Docker containers and Cloud Storage, the main advantages of the second implementation are that the Smart Contract implements an auction and bidding scheme to deliver tasks, and that the agents learn how to make predictions as they collect new experiences.
In addition, a third Blockchain-based architecture is proposed in the context of energy management in which a penalty-reward optimization scheme for the users in a district is implemented based on their consumption.
Still in the context of manufacturing, a general model for mass production systems based on Timed Coloured Petri Net and Particle Swarm Intelligence is proposed in part II. In the model, the Flexible Job Shop Sequence Problem is approached by the means of a Particle Swarm Optimization algorithm that can be efficiently implemented in a distributed environment.
Finally, in part III, a cooperative and distributed-oriented multi-agent DRL scheme is proposed in the domain of autonomous driving. In detail, the problem of autonomous intersection managements at unsignalized intersections is investigated in a complex scenario in which different classes of vehicles are involved including Connected Autonomous Vehicles, Connected Only emergency vehicles with high priority and regular unconnected vehicles. The main goal of the proposed scheme is to optimize traffic flow, ensure priorities and prevent collisions. The main contributions of the proposed approach are the novel state representation of the intersection state, which is also partially observable, the structure of the global reward function and subsequent implementation of Proximal Policy Optimization (PPO) algorithm to determine the best policy
Revoca o modifica delle concessioni idriche per motivi di compatibilità ambientale
No full textVengono analizzate le concessioni di acqua pubblica disciplinate dall'ordinamento. Vengono quindi ricostruiti i principi generali in tema di revoca e modifica unilaterale delle concessioni di beni pubblici in generale, con particolare riferimento alla posizione giuridica soggettiva del concessionario. Si verifica altresì l'impatto innovativo della normativa sulla pianificazione di bacino
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
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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