1,721,013 research outputs found
The Troublesome Probabilistic Powerdomain
No full textAbstractIn [12] it is shown that the probabilistic powerdomain of a continuous domain is again continuous. The category of continuous domains, however, is not cartesian closed, and one has to look at subcategories such as RB, the retracts of bifinite domains. [8] offers a proof that the probabilistic powerdomain construction can be restricted to RB.In this paper, we give a counterexample to Graham's proof and describe our own attempts at proving a closure result for the probabilistic powerdomain construction. We have positive results for finite trees and finite reversed trees. These illustrate the difficulties we face, rather than being a satisfying answer to the question of whether the probabilistic powerdomain and function spaces can be reconciled.We are more successful with coherent or Lawson-compact domains. These form a category with many pleasing properties but they fall short of supporting function spaces.Along the way, we give a new proof of Jones' Splitting Lemma.A number of people have been subjected to our (mostly flawed) attempts to prove a general closure theorem for the probabilistic powerdomain construction, and we gratefully acknowledge the patience and encouragement of the research teams in Darmstadt and Birmingham.We would also like to thank two anonymous referees for their comments and Mathias Kegelmann for very careful reading and many suggestions for improvement.The result in Section 4 was obtained while the first author visited the Isaac Newton Institute in Cambridge
Multi-games and bayesian nash equilibriums
Get PDFA growing awareness of the prominent role the environment plays in multi-agent systems has led to gradual acceptance of its importance by the multi-agent system community in general. Within this line of research, we propose a new class of games, called Multi-Games. A Multi-game is one in which a given number of players play a fixed finite number of basic games simultaneously. The basic games in a multi-game can be regarded as different environments for the players, and, in particular, we submit that multi-games can be used to model investment in multiple national and continental markets within a global economy. Furthermore, when the players' weights for different games in the multi-game are classed as private information or as types with given conditional probability distributions, we obtain a particular class of Bayesian games.
The main contribution of this thesis is to illustrate how, for the class of so-called completely pure regular multi-games with finite sets of types, the Nash equilibria of the basic games can be used to compute a Bayesian Nash equilibrium in multi-games, with complexity independent of the number of types. Following the presentation of the main results, the thesis presents two algorithms that allow us to establish whether we have a Bayesian Nash equilibrium which can be determined with lower computational complexity.Open Acces
Immersive virtual reality platform for self-attachment therapy
Get PDFWe have designed, developed, and tested an immersive virtual reality (VR) platform to practise protocols of the Self-attachment psychotherapy for treatment of depression and anxiety. The VR platform consists of both a high-end version based on Facebook’s Oculus and a low-end mobile version based on Google’s cardboard.
Under the Self-attachment therapeutic framework, the causes of mental disorders are traced back to the individual's insecure attachment with their primary caregiver during childhood. Self-attachment offers a self-administrable protocol in which the user imaginatively creates an internal affectional bond with their childhood self, based on mental imagery, and then simulates optimal parent-child interactions to re-parent the childhood self to emotional maturity, thus earning themselves secure attachment.
The platform offers a complementary visual tool for administering Self-attachment protocols; it enables the user to interact with their customised photorealistic childhood avatar (childhood self). The platform is developed in Unity 3D, a cross-platform game engine, and takes advantage of the itSeez3D Avatar SDK for generating a customised photorealistic 3D avatar head from a 2D childhood image of the user. The platform also offers facial and body animations for some of the basic emotions such as happy, sad, scared and joyful and it allows modifications to the avatar body and clothing colour.
A pilot study to compare the use of the avatar-based approach (VR) to Self-attachment with the conventional photo based approach showed promising results. More than 85% of the participants reported that their photorealistic childhood avatar in VR, in both the high-end version and the low-end version, was more relatable than their ordinary childhood photo. Participants also reported that the high-end version of the VR platform was more realistic and immersive than the low-end mobile version.Open Acces
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
Self-attachment: A self-administrable intervention for chronic anxiety and depression
Get PDFThere has been increasing evidence to suggest that the root cause of much
mental illness lies in a sub-optimal capacity for affect regulation. Cognition and
emotion are intricately linked and cognitive deficits, which are characteristic of
many psychiatric conditions, are often driven by affect dysregulation, which itself
can usually be traced back to sub-optimal childhood development as supported by
Attachment Theory. Individuals with insecure attachment types in their childhoods
are prone to a variety of mental illness, whereas a secure attachment type in childhood
provides a secure base in life. We therefore propose a holistic approach to
tackle chronic anxiety and depression, typical of Axis II clinical disorders, which
is informed by the development of the infant brain in social interaction with its
primary care-givers. We formulate, in a self-administrable way, the protocols governing
the interaction of a securely attached child with its primary care-givers that
produce the capacity for affect regulation in the child. We posit that these protocols
construct, by neuroplasticity and long term potentiation, new optimal neural
pathways in the brains of adults with insecure childhood attachment that suffer
from mental disorder. This procedure is called self-attachment and aims to help
the individuals to create their own attachment objects in the form of their adult self
looking after their inner child
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
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