2,925 research outputs found
Wi-Closure: Reliable and Efficient Search of Inter-robot Loop Closures Using Wireless Sensing
No full textIn this paper we propose a novel algorithm, Wi-Closure, to improve the computational efficiency and robustness of loop closure detection in multi-robot SLAM. Our approach decreases the computational overhead of classical approaches by pruning the search space of potential loop closures, prior to evaluation by a typical multi-robot SLAM pipeline. Wi-Closure achieves this by identifying candidates that are spatially close to each other measured via sensing over the wireless communication signal between robots, even when they are operating in non-line-of-sight or in remote areas of the environment from one another. We demonstrate the validity of our approach in simulation and in hardware experiments. Our results show that using Wi-closure greatly reduces computation time, by 54.1% in simulation and 76.8% in hardware experiments, compared with a multi-robot SLAM baseline. Importantly, this is achieved without sacrificing accuracy. Using Wi-closure reduces absolute trajectory estimation error by 98.0% in simulation and 89.2% in hardware experiments. This improvement is partly due to Wi-Closure's ability to avoid catastrophic optimization failure that typically occurs with classical approaches in challenging repetitive environments.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Learning & Autonomous Contro
WI Aids Safety
No full textNewspaper Article - 'WI Aids Safety' (Farm Safety - Reflector Tape) No dateAWI CollectionWI AIDS SAFETY — District roads in the
Echo Hill area, 35 miles northwest of Edmonton
are safer at night because of the Echo Hill
Women's Institute. Concerned over the hazards
posed by poorly marked machinery travelling
the roads, the WI raised $ 180 for nearly 200
yards of red reflective tape. With the aid of the
Echo Hill 4- H Club, the WI had the tape placed
in nearly 300 pieces of machinery along a 10-
mile portion of a district road. Official commendation
recently was given the project by the
Alberta Safety Council with an Outstanding
Achievement plaque. The picture shows Mrs.
William Price and Mrs. Lloyd McMillan, members
of the Echo Hill Women's Institute safety
committee, receiving the plaque from William
Perkins, the council's farm safety director
Distributed Multi-agent Negotiation for Wi-Fi Channel Assignment
No full textChannel allocation in dense, decentralized Wi-Fi networks is a challenging due to the highly nonlinear solution space and the difficulty to estimate the opponent’s utility model. So far, only centralized or mediated approaches have succeeded in applying negotiation to this setting. We propose the first two fully-distributed negotiation approaches for Wi-Fi channel assignment. Both of them leverage a pre-sampling of the utility space with simulated annealing and a noisy estimation of the Wi-Fi utility function. Regarding negotiation protocols, one of the approaches makes use of the Alternating Offers protocol, while the other uses the novel Multiple Offers Protocol for Multilateral Negotiations with Partial Consensus (MOPaC), which naturally matches the problem peculiarities. We compare the performance of our proposed approaches with the previous mediated approach, based on simple text mediation. Our experiments show that our approaches yield better utility outcomes, better fairness and less information disclosure than the mediated approach.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Interactive Intelligenc
Extracting corpus specific knowledge bases from Wikipedia
No full textThesauri are useful knowledge structures for assisting information retrieval. Yet their production is labor-intensive, and few domains have comprehensive thesauri that cover domain-specific concepts and contemporary usage. One approach, which has been attempted without much success for decades, is to seek statistical natural language processing algorithms that work on free text. Instead, we propose to replace costly professional indexers with thousands of dedicated amateur volunteers--namely, those that are producing Wikipedia. This vast, open encyclopedia represents a rich tapestry of topics and semantics and a huge investment of human effort and judgment. We show how this can be directly exploited to provide WikiSauri: manually-defined yet inexpensive thesaurus structures that are specifically tailored to expose the topics, terminology and semantics of individual document collections. We also offer concrete evidence of the effectiveness of WikiSauri for assisting information retrieval
Il Commentario della vita di Giannozzo Manetti di Vespasiano da Bisticci (con un’edizione critica e commentata del testo)
No full textThis work consists in a critical edition and a historical and cultural analysis of the Commentario della vita di Giannozzo Manetti (henceforth Commentario), a work written by Vespasiano da Bisticci (1422-1498). We propose a rereading of it, ascribing the Commentario to an environment of opposition to the Medici’s regime, and we suppose a date of composition in the afterwards of the Pazzi conspiracy.
The Commentario has already been published twice: a first time by Pietro Fanfani in 1862 and a second time by Aulo Greco in 1976. However, both publications are somewhat imprecise from the philological point of view, and limited insofar as they are only based on one version of the Commentario: in reality there are six witnesses with numerous authorial variants, the analysis of which enriches the interpretation of the work. In our dissertation, we highlight that the Commentario is not a mere literary exercise by the author but conveys in fact contents of protest towards the gradual establishment of a Medici lordship in Florence, in contrast to what has hitherto been assumed. Such contents are however cautiously expressed by the author through recourse to Giannozzo Manetti’s biography. Manetti was indeed an important character of Fifteenth Century Florentine public life who showed his reluctance to submit to the centralization of state power in Cosimo the Elder’s hands
Determine activity based on the classified identity of users by using Wi-Fi monitoring
No full textThe Wi-Fi technologies are used in everyday life on numerous applications that detect the crowd information for commercial, security and other reasons. The Wi-Fi monitoring can be used for tracking people when they are moving along different access points. The results from the Wi-Fi monitoring can provide the location of the users in an area and therefore, useful information can be extracted. The goal of this project is to recognize the activity of different users for different sessions of a Wi-Fi network. The Wi- Fi dataset that is used, is acquired from the Wi-Fi network of the Delft University of Technology (TU Delft). Initially, the estimation of the users’ occupation is determined with the use of a Markov model with the information that is derived from the Wi-Fi dataset. Their possible identity is used, in order to estimate the activity that a user is probably doing at a specific location of the research area. The results on the use of the research area, are calculated and visualised in different spatial levels, campus, building and floor level. The use of the building complex of the TU Delft Campus, is examined during irregular hours, to allow efficient real estate management and provide security solutions.Architecture and The Built EnvironmentGeo-information TechnologyGeomatics for the Built EnvironmentTRACK-i
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