164,212 research outputs found
An extension of a lemma of Dayawansa and its application in the design of extended observers for nonlinear systems
No full textIn this paper we show how, by extending a classical Lemma due to Dayawansa, it is possible to enhance the theory of robust extended observers so as to cover a wide class of nonlinear systems, namely those systems whose normal form is characterized by “time-dependent gains” in the “string of integrators between input and output”. Such class includes helicopters, quadrotors, robot arms and electric drives
Variations on the Author
No full text“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
Application of enhanced extended observer in station-keeping of a quadrotor with unmeasurable pitch and roll angles
No full textIn this paper we provide an example of application of the design of a control law that makes use of an enhanced version of the so-called extended observer. The enhancement in question reposes on the extension of a classical Lemma due to Dayawansa to the case of nonlinear systems whose normal form includes time-varying (and measurable) gains. The presented example concerns a station-keeping problem of a quadrotor with unmeasurable pitch and roll angles
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
Larry O. Spencer, Conference Author Presentation
No full textGen. Larry O. Spencer, USAF (Ret.), author of Dark Horse: A Journey from the Horseshoe to the Pentago
Recommended from our members
Pre-discovery Activity of New Interstellar Comet 2I/Borisov Beyond 5 AU
No full textComet 2I/Borisov, the first unambiguous interstellar comet ever found, was discovered in 2019 August at ~3 au from the Sun on its inbound leg. No pre-discovery detection beyond 3 au has yet been reported, mostly due to the comet's proximity to the Sun as seen from the Earth. Here we present a search for pre-discovery detections of comet Borisov using images taken by the Catalina Sky Survey, Pan-STARRS, and the Zwicky Transient Facility (ZTF), with a further comprehensive follow-up campaign being presented in Bolin et al. We identified comet Borisov in ZTF images taken in 2019 May and use these data to update its orbit. This allowed us to identify the comet in images acquired as far back as 2018 December, when it was 7.8 au from the Sun. The comet was not detected in 2018 November when it was 8.6 au from the Sun, possibly implying an onset of activity around this time. This suggests that the activity of the comet is either driven by a more volatile species other than H₂O, such as CO or CO₂, or by exothermic crystallization of amorphous ice. We derive the radius of the nucleus to be <7 km using the non-detection in 2018 November, and estimate an area of ~0.5–10 km² has been active between 2018 December and 2019 September, though this number is model-dependent and is highly uncertain. The behavior of comet Borisov during its inbound leg is observationally consistent with dynamically new comets observed in our solar system, suggesting some similarities between the two
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
The inner circle o f Archbishop Innokentiy (Borisov) on the example o f Filaret (Gumilevsky)
No full textДосліджено стосунки архієреїв Російської православної церкви Інокентія (Борисова) та Філарета (Гумилевського). Проаналізовано основні віхи життєвого шляху, наукові здобутки та епістолярну спадщину ієрархів. З’ясовано, що Філарет належав до інтелектуального оточення Інокентія, будучи одним із його друзів і однодумців.Исследовано отношения архиереев Российской православной церкви Иннокентия (Борисова) и Филарета (Гумилевского). Проанализированы основные вехи жизненного пути, научные достижения и эпистолярное наследие иерархов. Выяснено, что Филарет принадлежал к интеллектуальному окружению Иннокентия и был одним из его друзей
и единомышленников.The relations of the bishops of the Russian Orthodox Church Innokentiy
(Borisov) and Filaret (Gumilevsky) are investigated. The main milestones
of life’s path, scientific achievements and epistolary heritage of hierarchs
are analyzed. It was found out that Filaret belonged to the intellectual
environment of Innokentiy and was one of his friends and like-minded people
Strikes in Russia : the case of the coal-mining industry
No full textThis thesis presents an analysis of the character and significance of strikes in post-
Soviet Russia on the basis of a series of case studies of strikes in the coal-mining
industry. The central argument of the thesis is that the patterns of strike activity
have been conditioned by the forms of management and financing of the coal-mining
industry and by the strategy of the mining industry trade unions.
Following a review of the sociological and industrial relations literature on strikes,
the thesis opens with a detailed study of the 1989 miners' strike in Kuzbass. Here it
is shown that the original demands of the miners were taken up and generalised by
the structures of branch and local administrative power, and the strike was thereby
assimilated into the traditional structures of branch and regional lobbying for
resources in Moscow. This set the pattern for the subsequent organisation of strikes
in the state and state-subsidised sectors of the economy.
The coincidence of interests of miners with the branch and regional authorities in
1989 was determined by the centralised management and financing of the coal-mining
industry. The system of subsidies to the industry reproduced this structure
even after the `transition to a market economy', although the financial and political
weakening of the state amid intensified competition for resources made it
increasingly difficult for the state to meet all the demands put on it. An analysis of
the 1993 miners' strike in Ukrainian Donbass shows how these constraints meant
that the miners were used by the directors to achieve their own ends. This is
followed by an account of the relationship between the lobbying activity of the
coal-mining industry, conflicts within the government apparatus, changing forms of
financing of the industry and the organisation of nation-wide miners' actions,
centred on the 1995 and 1996 miners' strikes.
The changes in the system of management and financing of the coal-mining
industry meant that the trade unions sought to contain conflict within the enterprise
in the attempt to concentrate their efforts on regional and national campaigns in
collaboration with management. The final three substantive chapters of the thesis
explore the implications of the increasing isolation and fragmentation of the miners
through a series of case studies of strikes in Kuzbass and Rostov over the period
1997-9. The final chapter draws together the general themes addressed in the thesis
- …
