1,721,038 research outputs found
Bootstrapping the Dynamic Gait Controller of the Soft Robot Arm
No full textIn this paper, we propose a novel dynamic gait controller for the repetitive behavior of soft robot manipulators performing routine tasks. Compliance with soft robots is advantageous when the robot interacts with living organisms and other fragile objects. However, predicting and controlling repetitive behavior is challenging because of hysteresis and non-linear dynamics governing the interactions. Existing priorfree methods track the dynamic state using recurrent neural networks or rely on known generalized coordinates describing the robot's state. We propose to model the interaction induced by the repetitive behavior as gait dynamics and represent the dynamic state with Central Pattern Generator (CPG) tracking the motion phase and thus reduce the complexity of the robot's forward model. The proposed method bootstraps an ensemble of the forward models exploring multiple dynamic contexts that are expanded as it searches for repetitive motion producing the target repetitive behavior. The proposed approach is experimentally validated on a pneumatically actuated soft robot arm I-Support, where the method infers gaits for different targets
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
Risk Aware Planning for Urban Air Mobility
Get PDFPorucha letadla během letu může vést až k jeho havárii, což představuje možné riziko i pro osoby a majetek na zemi, a to zejména ve městském prostředı́. Vzniku poruchy nelze zcela zabránit, a proto jsou studovány přı́stupy minimalizujı́cı́ důsledky poruchy, a tedy možná rizika. Jednı́m z existujı́cı́ch přı́stupů je plánovánı́ trajektoriı́, které vedou k menšı́m škodám v přı́padě poruchy. Riziko důsledku úplné ztráty tahu během letu může být plně eliminováno bezpečným nouzovým přistánı́m, pokud je v dosahu mı́sto pro přistánı́. V této práci proto navrhujeme novou metodu plánovánı́ trajektoriı́, která nejen zohledňuje riziko, ale také garantuje existenci bezpečné trajektorie nouzového přistánı́ v přı́padě selhánı́ motoru. Dopad navrhovaného řešenı́ pro minimalizaci rizika naplánovaných trajektoriı́ byl empiricky vyhodnocen v simulovaném realistickém městském scénáři. V porovnánı́ s nejkratšı́ trajektoriı́ a trajektoriı́ uvažujı́cı́ pouze riziko, plánuje navržená metoda trajektorie s významně nižšı́m celkovým rizikem. Proto lze na základě v práci dosažených výsledků konstatovat, že navržené plánovánı́ zohledňujı́cı́ riziko s garancı́ bezpečného nouzového přistánı́ je vhodnou metodou plánovánı́ trajektoriı́ pro městskou leteckou mobilitu.Aircraft in-flight failures cannot be entirely prevented, and they may lead up to a crash of the aircraft. Such a failure poses a risk also to people and properties on the ground, especially in the urban environment. Current state-of-the-art approaches minimize the risk by determining trajectories resulting in less damage in the case of a failure. Thus, they are minimizing the consequences of a failure. However, the risk of an in-flight loss of thrust failure can be eliminated by an emergency landing if a landing site is reachable. Therefore, we propose a novel risk-aware trajectory planning that minimizes risk to people or damage on the ground while an option of safe emergency landing is guaranteed in the loss of thrust. Henceforth, the overall risk is minimized. The proposed method has been empirically evaluated on a simulated realistic urban scenario. A significant risk reduction is achieved compared to the shortest and risk-aware only trajectories, based on the reported results. The proposed risk-aware planning with safe emergency landing seems to be suitable trajectory planning for urban air mobility
Sampling Strategies in Optimal Motion Planning for Inspection Missions with Non-Holonomic Vehicles
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