1,720,995 research outputs found
Generalization in deep learning
No full textTiefe neuronale Netze sind Schlüsselmodelle des maschinellen Lernens und eine potenzielle Basis für allgemeine künstliche Intelligenz. Ihr Erfolg beruht auf heuristischen Techniken und umfangreichen Ressourcen. Fortschritte erfordern neue Heuristiken sowie effizientere Nutzung von Daten und Rechenkapazität. Ein tiefgehendes Verständnis ist entscheidend für ihre Zuverlässigkeit.
Meine Dissertation zielt darauf ab, das Verständnis tiefer Netze zu verbessern, insbesondere ihre Generalisierungsfähigkeit mathematisch zu beschreiben und praktisch nutzbar zu machen. Ich nutze eine informationstheoretische Perspektive und die Verlustflächengeometrie. Zudem untersuche ich föderiertes Lernen als praxisnahe Lösung. Meine Forschung liefert neue Erkenntnisse zur Informationsverfolgung, ein Abflachungsmaß für Generalisierung und Kommunikationsstrategien zur Effizienzsteigerung in föderierten Lernsystemen
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
Information-theoretic perspective of federated learning
Get PDFAn approach to distributed machine learning is to train models on local datasets and aggregate these models into a single, stronger model. A popular instance of this form of parallelization is federated learning, where the nodes periodically send their local models to a coordinator that aggregates them and redistributes the aggregation back to continue training with it. The most frequently used form of aggregation is averaging the model parameters, e.g., the weights of a neural network. However, due to the non-convexity of the loss surface of neural networks, averaging can lead to detrimental effects and it remains an open question under which conditions averaging is beneficial. In this paper, we study this problem from the perspective of information theory: We measure the mutual information between representation and inputs as well as representation and labels in local models and compare it to the respective information contained in the representation of the averaged model. Our empirical results confirm previous observations about the practical usefulness of averaging for neural networks, even if local dataset distributions vary strongly. Furthermore, we obtain more insights about the impact of the aggregation frequency on the information flow and thus on the success of distributed learning. These insights will be helpful both in improving the current synchronization process and in further understanding the effects of model aggregation
Introducing noise in decentralized training of neural networks
No full textS.37-48It has been shown that injecting noise into the neural network weights during the training process leads to a better generalization of the resulting model. Noise injection in the distributed setup is a straightforward technique and it represents a promising approach to improve the locally trained models. We investigate the effects of noise injection into the neural networks during a decentralized training process. We show both theoretically and empirically that noise injection has no positive effect in expectation on linear models, though. However for non-linear neural networks we empirically show that noise injection substantially improves model quality helping to reach a generalization ability of a local model close to the serial baseline
Novelty Detection in Sequential Data by Informed Clustering and Modeling
Get PDFNovelty detection in discrete sequences is a challenging task, since
deviations from the process generating the normal data are often small or
intentionally hidden. Novelties can be detected by modeling normal sequences
and measuring the deviations of a new sequence from the model predictions.
However, in many applications data is generated by several distinct processes
so that models trained on all the data tend to over-generalize and novelties
remain undetected. We propose to approach this challenge through decomposition:
by clustering the data we break down the problem, obtaining simpler modeling
task in each cluster which can be modeled more accurately. However, this comes
at a trade-off, since the amount of training data per cluster is reduced. This
is a particular problem for discrete sequences where state-of-the-art models
are data-hungry. The success of this approach thus depends on the quality of
the clustering, i.e., whether the individual learning problems are sufficiently
simpler than the joint problem. While clustering discrete sequences
automatically is a challenging and domain-specific task, it is often easy for
human domain experts, given the right tools. In this paper, we adapt a
state-of-the-art visual analytics tool for discrete sequence clustering to
obtain informed clusters from domain experts and use LSTMs to model each
cluster individually. Our extensive empirical evaluation indicates that this
informed clustering outperforms automatic ones and that our approach
outperforms state-of-the-art novelty detection methods for discrete sequences
in three real-world application scenarios. In particular, decomposition
outperforms a global model despite less training data on each individual
cluster.Comment: AI&HCI Workshop at the 40th International Conference on Machine
Learning (ICML), Honolulu, Hawaii, USA. 202
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