1,720,981 research outputs found
Balancing Reconstruction Error and Kullback-Leibler Divergence in Variational Autoencoders
Full text linkLikelihood-based generative frameworks are receiving increasing attention in the deep learning community, mostly on account of their strong probabilistic foundation. Among them, Variational Autoencoders (VAEs) are reputed for their fast and tractable sampling and relatively stable training, but if not properly tuned they may easily produce poor generative performances. The loss function of Variational Autoencoders is the sum of two components, with somehow contrasting effects: the reconstruction loss,improving the quality of the resulting images, and the Kullback-Leibler divergence, acting as a regularizer of the latent space. Correctly balancing these two components is a delicate issue, and one of the major problems of VAEs. Recent techniques address the problem by allowing the network to learn the balancing factor during training, according to a suitable loss function. In this article, we show that learning can be replaced by a simple deterministic computation, expressing the balancing factor in terms of a running average
of the reconstruction error over the last minibatches. As a result, we keep a constant balance between the two components along training: as reconstruction improves, we proportionally decrease KL-divergence in order to prevent its prevalence, that would forbid further improvements of the quality of reconstructions. Our technique is simple and effective: it clarifies the learning objective for the balancing factor, and it produces faster and more accurate behaviours. On typical datasets such as Cifar10 and CelebA, our technique sensibly outperforms all previous VAE architectures with comparable parameter capacity
L’edificio collettivo nel villaggio operaio-rurale “Alessandro Mussolini” a Forlì (1937-1984)
No full textNel fenomeno che negli anni Trenta diede luogo alla realizzazione di nuove città e villaggi rurali e operai in Italia e all’estero acquisiscono un ruolo importante i principi di “ritorno alla terra” e “ruralità”. Posto all’estremità del Villaggio operaio “Alessandro Mussolini” a Forlì, l’edificio collettivo realizzato nel 1937 è il risultato di una composizione di volumi che mettono in scena questi principi mostrando la forte relazione che il villaggio instaura con il paesaggio agrario in cui si inserisce
Formally Verifying Function Scheduling Properties in Serverless Applications
Full text linkFunction as a service (FaaS) is a serverless cloud execution model offering cost-efficiency, scalability, and simplified development by enabling developers to focus on code and delegate server management and application scaling to the serverless platform. Early FaaS implementations provided no control to users over function
placement, but raising data locality-bound scenarios motivated new implementations with user-defined constraints over function allocations, e.g., to keep functions accessing a database close to the latter, with the aim of reducing latency, enhancing security, or complying with regulations. In this article, we show how, by leveraging the Allocation Priority Policies language—used for controlling function scheduling and state-of-the-
art planning tools, it is possible to enforce security properties and data-locality constraints, thereby guiding the definition of fine-grained serverless scheduling policies
Introduction to The Middle East and the Cold War: Between Security and Development
No full textThe Cold War was a multidimensional conflict whose main area of contention was post-WWII Europe but whose goals and scope reached far beyond the so-called “old continent”. It would be absurd and historically false to determine the political history of the post-WWII Middle East only along the dynamics and time- frame of the Cold War: the Arab-Israeli conflict outlived the fall of the Berlin Wall, the “socialist” republics of Syria and Iraq, for example, survived their major allies of the Eastern bloc, and the Islamic Republic of Iran also shuffled all cards of Cold War alignments and theories. However, evidence from fresh research and recent historiography has shown how the Cold War conditioned the conflicts and dynamics of the Middle East, whose origins were not of its making but whose outcomes were able to affect the strategic balance of power between the two camps, and thus legitimated their interventions. This volume gathers the contributions of young scholars involved with the international history of the Middle East in the 1950s and 1960s. Building on the literature concerning strategic issues, this volume focuses on the linkages between security and development: more precisely, between Cold War interventions and the political and economic dynamics of the postcolonial Middle East
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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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