1,721,673 research outputs found
Tight Bounds for Deterministic h-Shot Broadcast in Ad-Hoc Directed Radio Networks
No full textWe consider the classical broadcast problem in ad-hoc (that is, unknown topology) directed radio networks with no collision detection, under the additional assumption that at most h transmissions (shots) are available per node. We focus on adaptive deterministic protocols for small values of h. We provide asymptotically matching lower and upper bounds for the cases h=2 and h=3. While for h=2 our bound is quadratic, similar to the bound obtained for oblivious protocols, for h=3 we prove a sub-quadratic bound of Theta(n^2 log log n / log n), where n is the number of nodes in the network. The latter is the first result showing an adaptive algorithm which is asymptotically faster than oblivious h-shot broadcast protocols, for which a tight quadratic bound is known for every constant h. Our upper bound for h=3 is constructive, making use of constructions of graphs with large girth. We also show an improved upper bound of O(n^(1+alpha/sqrt{h})) for h >= 4, where alpha is an absolute constant independent of h. Our upper bound for h >= 4 is non-constructive
Punishment and protest
No full textEthicists often approach our task by thinking about the norms that apply to act types. We ask, for example, what it means to punish, to make amends, or to forgive, and what conditions govern the appropriate performance of actions that fall within these types. However, actions often do not fall neatly into only one action type. This chapter discusses two cases that can be interpreted both as acts of protest and as acts of what Linda Radzik calls “informal social punishment.” Since the norms that govern these two types diverge, the fact that a particular action can be interpreted in either of these ways poses a challenge for anyone who might be seeking moral guidance from the type to which the action belongs. The cases highlight a theoretical gap that needs to be filled not only by accounts of social punishment or protest but also by ethicists who would use this approach to think about actions of other overlapping types
Belarusian literature in the research of Ryszard Radzik
No full textThe author discusses the importance of Belarusian studies conducted by Polish sociologist Ryszard Radzik. The scientific value of R. Radzik’s research of the specifics of Belarusian identity and the ways of its formation is shown. Special attention is paid to the understanding of the literary discourse of R. Radzik’s works. The author analyzes the researcher’s views on the works of writers of the XIX century, as well as V. Lastousky, Yakub Kolas. The difference in the perception and interpretation of the writers’ works by Polish and Belarusian researcher is conditioned by different historical experience, is indicated.Autorka artykułu analizuje naukowe owoce badań białoruskich polskiego socjologa Ryszarda Radzika. Pokazano naukową wartość badań R. Radzika nad specyfiką tożsamości białoruskiej i sposobami jej kształtowania. Autorka szczególną uwagę zwraca na rozumienie dyskursu literackiego w pracach R. Radzika. Analizowane są poglądy badacza na twórczość XIX-wiecznych pisarzy, a także W. Lastouskiego, J. Kołasa. Pokazano różnicę w percepcji i interpretacji dzieł pisarzy między badaczami polskimi i białoruskimi, która wynika z odmiennych doświadczeń historycznych.У артыкуле разглядаецца навуковы плён беларусазнаўчых штудый польскага сацыёлага Рышарда Радзіка. Паказваецца навуковая вартасць даследаванняў Р. Радзікам спецыфікі беларускай ідэнтычнасці і шляхоў яе станаўлення. Асаблівая ўвага нададзена асэнсаванню літаратуразнаўчага дыскурсу работ Р. Радзіка. Аналізуюцца погляды даследчыка на творы пісьменнікаў ХІХ ст., а таксама – В. Ластоўскага, Я. Коласа. Паказваецца рознасць ва ўспрыманні і інтэрпрэтацыі творчасці пісьменнікаў паміж польскім даследчыкам і беларускімі, што абумоўлена розным гістарычным вопытам
note: An alternative characterization of the weighted Banzhaf value
No full textWe provide a new characterization of the weighted Banzhaf value derived from some postulates in a recent paper by Radzik, Nowak and Driessen [7]. Our approach owes much to the work by Lehrer [4] on the classical Banzhaf value based on the idea of amalgamation of pairs of players and an induction construction of the value. Compared with the approach in [7] we consider two new postulates: a weighted version of Lehrer's "2-efficiency axiom" [4] and a generalized "null player out" property studied in terms of symmetric games by Derks and Haller [2].Cooperative games, Banzhaf value, weighted value.
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
Supermodular social games
No full textA social game is a generalization of a strategic-form game, in which not only the payoff of each player depends upon the strategies chosen by their opponents, but also their set of admissible strategies. Debreu (1952) proves the existence of a Nash equilibrium in social games with continuous strategy spaces. Recently, Polowczuk and Radzik (2004) have proposed a discrete counterpart of Debreu's theorem for two-person social games satisfying some ``convexity properties'. In this note, we define the class of supermodular social games and give an existence theorem for this class of games.Strategic-form games, social games, supermodularity, Nash equilibrium, existence.
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
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