307,730 research outputs found
ROS-based implementation and evaluation of an energy-aware multi-robot system for exploration
No full textLAUREA MAGISTRALEI compiti che vengono affidati ai robot moderni diventano ogni giorno più complessi, rendendendo spesso inefficiente l'utlizzo di un singolo robot in molte applicazioni. In questo lavoro ci concentriamo sull'esplorazione di ambienti a priori non noti, ad esempio con l'intendo di individuare e soccorrere vittime in zone pericolose.
Al fine di otterene un comportamento efficiente, uno dei problemi da gestire quando si decide di impiegare un gruppo di robot è il coordinamento tra questi ultimi. Oltre ciò, è anche necessario tenere in considerazione la limitata energia disponibile dai robot mobili, rendendo indispensabile sviluppare metodi per ridurre gli sprechi di energia e ricaricare occasionalmente i robot.
Sebbene il tema del coordinamento sia stato largamente studiato in letteratura e oggigiorno siano disponibili diversi framework (come ad esempio quelli basati su ROS) per sviluppare software per sistemi multi-robot coordinati, solo un numero molto esiguo di lavori si sono focalizzati sul tema dell'esplorazione di ambienti sconosciuti usando robot mobili con energia limitata. Questo problema è affrontato nel lavoro di Rappaport e Bettstetter: l'approccio proposto dagli autori appare molto promettente, tuttavia è stato testato utilizzando un simulatore semplificato, lasciando quindi aperta la domanda sulle prestazioni del modello in applicazioni più realistiche.
Questa tesi migliora l'approccio proposto da Rappaport e Bettstetter al fine di adattarlo ad applicazioni e scenari più realistici. In aggiunta, questo lavoro vede l'implementazione in ROS del citato approccio, la raccolta di dati utilizzndo il software risultante e l'analisi critica delle performance del sistema dipendentemente dallo scenario di esplorazione (ambiente esplorato, numero di robot impiegati, ecc.), che dimostriamo avere un impatto significativo sui risultati.The tasks that robots are required to execute are becoming more and more complex, and a single robot is often no longer the best choice for many applications. In this work, we focus on the exploration of a priori unknown environments, for instance to search and rescue victims in hazardous sites. One of the issues when dealing with a team of robots is that, in order to perform efficiently, the robots are required to coordinate intelligently. Moreover, when dealing with mobile multi-robot systems we also have to consider the limited energy available to the robots, calling for methods that avoid energy wastes and occasionally recharge the battery.
While the coordination issue has been widely studied in the literature and several frameworks to develop software for coordinated multi-robot systems, like those based on ROS, have been proposed, to the best of our knowledge there exist very few works on coordinated energy-aware exploration of initially unknown environments. One of them is the work of Rappaport and Christian Bettstetter. The approach proposed by the authors appears to be very promising, but it is tested using a simplified simulator, thus leaving open the question of how it works in more realistic settings.
This thesis improves the approach proposed by Rappaport and Christian Bettstetter in order to adapt it to more realistic scenarios and applications. In addition, this thesis contributes the implementation in ROS of the new approach, the collection of data using the software developed in ROS, and their analysis in order to critically study the performance of the system according to the exploration scenario (size of the environment to be explored, number of employed robots, etc.), that we show to have a significant impact on the results
Disturber of the peace: Touches to the portrait of A. G. Rappaport
No full textAlexander Herbertovich Rappaport is a philosopher, architect, art historian, author of many articles and books on the theory of architecture and art history, author of the unique blog “Tower and Maze”, where he regularly publishes his reflections. A huge influence on Rappaport’s formation was his work in the Moscow Methodological Circle of Georgy Petrovich Shchedrovitsky (MMC). In 1979 he left the MMC and since the early 1980s he has been engaged in phenomenology, a direction in philosophy, the founder of which was Edmund Husserl. Most of A. G. Rappaport’s articles and books are written within the framework of phenomenology, but the school of thought that Rappaport underwent at MMK had an undeniable influence on his work. Rappaport’s works merge Shchedrovitsky’s methodology, phenomenology and poetry. © 2023 Russian Academy of Architecture and Construction Sciences, Vostoksibacademcenter. All rights reserved
Quatro discussões sobre Antropologia, História e seus muitos indígenas na América Latina: entrevistas com Guillermo de la Peña, Joanne Rappaport, Núria Sala e Víctor Bretón
No full textAcademic Interview: Guillermo de la Peña, Joanne Rappaport, Núria Sala e Víctor BretónEntrevista Académica: Guillermo de la Peña, Joanne Rappaport, Núria Sala e Víctor BretónEntrevista: Guillermo de la Peña, Joanne Rappaport, Núria Sala e Víctor Bretó
Quatro discussões sobre Antropologia, História e seus muitos indígenas na América Latina: entrevistas com Guillermo de la Peña, Joanne Rappaport, Núria Sala e Víctor Bretón
No full textAcademic Interview: Guillermo de la Peña, Joanne Rappaport, Núria Sala e Víctor BretónEntrevista Académica: Guillermo de la Peña, Joanne Rappaport, Núria Sala e Víctor BretónEntrevista: Guillermo de la Peña, Joanne Rappaport, Núria Sala e Víctor Bretó
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
A note on the performance of Rappaport's medium, compared with Rappaport‐Vassiliadis broth, in the isolation of salmonellas from meat products, after pre‐enrichment
No full textSalmonellas were isolated from meat products using a slightly modified Rappaport's enrichment medium (R25), Rappaport‐Vassiliadis procedure (Rappaport's broth containing 10 ml instead of 30 ml of Malachite Green solution and incubated at 43oC instead of 37oC), and Muller‐Kauffmann's tetrathionate broth. From 255 samples, 89 were found positive with the Rappaport‐Vassiliadis procedure, 83 with the R25 broth, whereas only 43 were positive with Muller‐Kauffmann broth. It is concluded that the R25 medium may be used as an alternative to the more effective Rappaport‐Vassiliadis broth when the only available incubation temperature is 37oC. Copyright © 1982, Wiley Blackwell. All rights reserve
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
Beyond Participant Observation: Collaborative Ethnography asTheoretical Innovation
No full textPortuguese translation of the article RAPPAPORT, Joanne. “Beyond Participant Observation: Collaborative Ethnography as Theoretical Innovation”, University of Nebraska Press: Collaborative Anthropologies, v.1, 2008, p. 1-31.
Available at: https://muse.jhu.edu/article/367015 Tradução do texto RAPPAPORT, Joanne. “Beyond Participant Observation: Collaborative Ethnography as Theoretical Innovation”, University of Nebraska Press: Collaborative Anthropologies, v.1, 2008, p. 1-31.
Disponível em: https://muse.jhu.edu/article/367015
Collection d'Incunables imprimés en Italie décrits avec soin et accompagnés de notes bibliographiques Catalogue XVII
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