1,721,096 research outputs found
Usaldusväärse reaalajas trajektoori optimeerimise suunas
No full textVäitekirja elektrooniline versioon ei sisalda publikatsiooneLiikumise planeerimine on robootika põhiaspekt, mis võimaldab robotitel liikuda läbi keeruliste ja muutuvate keskkondade. Levinud lähenemisviis liikumise planeerimise probleemide lahendamiseks on trajektoori optimeerimine. Trajektoori optimeerimine võib matemaatiliste aparatuuride kaudu esindada robotite kõrgtasemelist käitumist. Siiski praegustel trajektoori optimeerimise lähenemisviisidel on kaks peamist väljakutset. Esiteks, sõltub nende lahendus suuresti esialgsest oletusest ja nad kipuvad takerduma kohalike miinimumidesse. Teiseks seisavad nad silmitsi mastaapsuse piirangutega, kuna kitsenduste arv suureneb.
Antud doktoritöö püüab nende väljakutsetega toime tulla, tutvustades nelja uuenduslikku trajektoori optimeerimise algoritmi, et parandada usaldusväärsust, mastaapsust ja arvutusliku efektiivsust.
Pakutud algoritmidel on kaks uudset aspekti. Esimene oluline uuendus on kinemaatiliste kitsenduste ja kokkupõrke vältimise kitsenduste ümberkujundamine. Teine oluline uuendus seisneb algoritmide väljatöötamises, mis kasutavad tõhusalt graafikaprotsessori kiirendite paralleelset arvutust. Kasutades ümbersõnastatud kitsendusi ja võimendades graafikaprotsessoritede arvutusvõimsust, näitavad selle lõputöö pakutud algoritmid oluliselt tõhususe ja mastaapsuse paranemist võrreldes olemasolevate meetoditega. Paralleelarvutus võimaldab kiiremat arvutusaega, võimaldades dünaamilistes keskkondades reaalajas otsuseid langetada. Lisaks on algoritmid loodud kohanema keskkonnamuutustega, tagades tugeva jõudluse isegi tundmatu- tes ja segastes tingimustes.
Iga pakutud optimeerija põhjalik võrdlusanalüüs kinnitab nende tõhusust. Tänu põhjalikule hindamisele ületavad pakutud algoritmid pidevalt tipptasemel meetodeid erinevate mõõdustike kaudu, näiteks sujuvuse kulude ja arvutusaja osas. Need tulemused rõhutavad pakutud trajektoori optimeerimise algoritmide potentsiaali robootikarakenduste liikumise planeerimise tipptasemel märkimisväärselt edendada.
Kokkuvõttes annab antud doktoritöö olulise panuse trajektoori optimeerimise algoritmide valdkonnale. See tutvustab uuenduslikke lahendusi, mis käsitlevad konkreetselt olemasolevate meetodite ees seisvaid väljakutseid. Kavandatud algoritmid sillutavad teed tõhusamatele ja jõulisematele liikumisplaneerimise lahendustele robootikas, võimendades paralleelset arvutust ja spetsiifilisi matemaatilisi struktuure.Motion planning is a key aspect of robotics, allowing robots to move through complex and changing environments. A common approach to address motion planning problems is trajectory optimization. Trajectory optimization can represent the high-level behaviors of robots through mathematical formulations. However, current trajectory optimization approaches have two main challenges. Firstly, their solution heavily depends on the initial guess, and they are prone to get stuck in local minima. Secondly, they face scalability limitations by increasing the number of constraints.
This thesis endeavors to tackle these challenges by introducing four innovative trajectory optimization algorithms to improve reliability, scalability, and computational efficiency.
There are two novel aspects of the proposed algorithms. The first key innovation is remodeling the kinematic constraints and collision avoidance constraints. Another key innovation lies in the design of algorithms that effectively utilize parallel computation on GPU accelerators. By using reformulated constraints and leveraging the computational power of GPUs, the proposed algorithms of this thesis demonstrate significant improvements in efficiency and scalability compared to the existing methods. Parallelization enables faster computation times, allowing for real-time decision-making in dynamic environments. Moreover, the algorithms are designed to adapt to changes in the environment, ensuring robust performance even in unknown and cluttered conditions.
Extensive benchmarking for each proposed optimizer validates their efficacy. Through comprehensive evaluation, the proposed algorithms consistently outperform state-of-the-art methods across various metrics, such as smoothness costs and computation time. These results highlight the potential of the proposed trajectory optimization algorithms to significantly advance the state-of-the-art in motion planning for robotics applications.
Overall, this thesis makes a significant contribution to the field of trajectory optimization algorithms. It introduces innovative solutions that specifically address the challenges faced by existing methods. The proposed algorithms pave the way for more efficient and robust motion planning solutions in robotics by leveraging parallel computation and specific mathematical structures.https://www.ester.ee/record=b568560
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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