1,720,959 research outputs found
A digital twin infrastructure for designing an underwater survey with a professional DPV
No full textThis paper presents a digital twin infrastructure developed to study and test the buoyancy set-up of a diver propulsion vehicle (DPV) with and without payloads prior to the underwater survey. In order to obtain the final software simulator, MATLAB/Simulink (for physical and mathematical models) was connected with Unity (for robot and environment visualization and navigation). A user interface is also presented to simulate the model directly and guide the user in adding objects to the DPV and in running the code to recalculate the fundamental parameters of the model. The system was verified and validated through case studies designed to test the behavior of the virtual DPV
Control Engineering and Robotics since Primary School: an Infrastructure for creating the Digital Twin model of the Learning Class
No full textControl engineering has a cross-boundary nature because its applications span over a wide range of fields, among which science, technology, engineering, and mathematics (STEM). Creating an automation literacy from the Primary School's age is beneficial for pupils because it supports the development of valuable skills that allow the comprehension and analysis of real-world phenomena. Even if many researchers and policymakers have advocated for engineering education since early education, it is usually kept for undergraduate and graduate-level education. What prevents systems theory and control education from being integrated into K12 education is the lack of available educational resources and the lack of indicators to represent the learning gain of students. To help teachers in the latter aspect, a solution can be studying the entire process as a cyber-physical human system (CPHS). The paper consists of a brief report about the work carried out by authors to represent the entire classroom as a CPHS where the physical robots designed by students, humans (teachers and learners), and cybertechnologies are interconnected to accomplish a goal which is learning. The entire infrastructure could be seamlessly deployed into the classroom, supporting learning assessment and the feedback process starting from the deployment of a (quasi) real-time intelligent collection system
A Digital Twin Infrastructure for NGC of ROV during Inspection
Full text linkRemotely operated vehicles (ROVs) provide practical solutions for a wide range of activities in a particularly challenging domain, despite their dependence on support ships and operators. Recent advancements in AI, machine learning, predictive analytics, control theories, and sensor technologies offer opportunities to make ROVs (semi) autonomous in their operations and to remotely test and monitor their dynamics. This study moves towards that goal by formulating a complete navigation, guidance, and control (NGC) system for a six DoF BlueROV2, offering a solution to the current challenges in the field of marine robotics, particularly in the areas of power supply, communication, stability, operational autonomy, localization, and trajectory planning. The vehicle can operate (semi) autonomously, relying on a sensor acoustic USBL localization system, tethered communication with the surface vessel for power, and a line of sight (LOS) guidance system. This strategy transforms the path control problem into a heading control problem, aligning the vehicle’s movement with a dynamically calculated reference point along the desired path. The control system uses PID controllers implemented in the navigator flight controller board. Additionally, an infrastructure has been developed that synchronizes and communicates between the real ROV and its digital twin within the Unity environment. The digital twin acts as a visual representation of the ROV’s movements and considers hydrodynamic behaviors. This approach combines the physical properties of the ROV with the advanced simulation and analysis capabilities of its digital counterpart. All findings were validated at the Point Rouge port located in Marseille and at the port of Ancona. The NGC implemented has proven positive vehicle stability and trajectory tracking in time despite external interferences. Additionally, the digital part has proven to be a reliable infrastructure for a future bidirectional communication system
A novel DPV as a holistic platform for real-time physiological status assessment of divers
No full textThis paper presents the work performed to integrate a sensors network to a more complex and extensive system, represented by the architecture that constitutes the main output of the DiveSafe European project (G.A. EASME/EMFF/2017/1.2.1.12/SI/02/ SI2.789635). The latter also includes an underwater scooter, a Docking Station, a tablet and a whole communication system between the surface and the underwater environment in which the diver is located, as well as a remote server that also allows the execution of 3D reconstruction of the appropriately photographed environment. The sensors system presented here allows to monitor the main indicators of the diver's health during underwater activities. Through these sensors, it is therefore possible to real-time monitor physiological values such as breath rate, heartbeat and glucose levels, as well as to provide information on the decompression phases execution, in order to safely ascend once the underwater work is finished. The electronic components are located inside a special waterproof box that the diver wears at the height of the belt. The main sensors have been validated, motivating the choices made
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
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