1,720,992 research outputs found
Conversion of real-numbered privacy-preserving problems into the integer domain
No full textSecure Multiparty Computation (SMC) enables untrusting parties to jointly compute a function on their respective inputs without revealing any information but the outcome. Almost all techniques for SMC support only integer inputs and operations. We present a secure scaling protocol for two parties to map real number inputs into integers without revealing any information about their respective inputs. The main component is a novel algorithm for privacy-preserving random number generation. We also show how to implement the protocol using Yao’s garbled circuit technique.Wilko Henecka, Nigel Bean, and Matthew Rougha
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
Hiccups on the road to privacy-preserving linear programming
Full text linkLinear programming is one of maths’ greatest contributions to industry. There are many places where linear programming could be beneficially applied across more than one company, but there is a roadblock: companies have secrets. The data needed for joint optimization may need to be kept private because of concerns about leaking competitively sensitive data, or due to privacy legislation. Recent research has tackled the problem of privacy-preserving linear programming. One appealing group of approaches uses a ‘disguising’ transformation to allow one party to perform the joint optimization without seeing the secret data of the other parties. These approaches are very appealing from the point of view of simplicity, efficiency, and flexibility, but we show here that all of the existing transformations have a critical flaw.Alice Bednarz, Nigel Bean and Matthew Rougha
Where’s Waldo? practical searches for stability in iBGP
Full text linkCopyright © 2008 IEEEWhat does a child’s search of a large, complex cartoon for the eponymous character (Waldo) have to do with Internet routing? Network operators also search complex datasets, but Waldo is the least of their worries. Routing oscillation is a much greater concern. Networks can be designed to avoid routing oscillation, but the approaches so far proposed unnecessarily reduce the configuration flexibility. More importantly, apparently minor changes to a configuration can lead to instability. Verification of network stability is therefore an important task, but unlike the child’s search, this problem is NP hard. Until now, no practical method was available for large networks. In this paper, we present an efficient algorithm for proving stability of iBGP, or finding the potential oscillatory modes, and demonstrate its efficacy by applying it to the iBGP configuration of a large Tier-2AS.Ashley Flavel, Matthew Roughan, Nigel Bean and Aman Shaik
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
Node localisation in wireless ad hoc networks
Full text linkWireless ad hoc networks often require a method for estimating their nodes' locations. Typically this is achieved by the use of pair-wise measurements between nodes and their neighbours, where a number of nodes already accurately know their location and the remaining nodes must calculate theirs using these known locations. Typically, a minimum mean square estimate (MMSE), or a maximum likelihood estimate (MLE) is used to generate the unknown node locations, making use of range estimates derived from measurements between the nodes. In this paper we investigate the efficacy of using radio frequency, received signal strength (RSS) measurements for the accurate location of the transmitting nodes over long ranges. We show with signal strength measurements from three or more wireless probes in noisy propagation conditions, that by using a weighted MMSE approach we can obtain significant improvements in the variance of the location estimate over both the standard MMSE and MLE approaches.Jon Arnold, Nigel Bean, Miro Kraetzl, Matthew Rougha
A framework for streamlined statistical prediction using topic models
No full textIn the Humanities and Social Sciences, there is increasing interest in approaches to information extraction, prediction, intelligent linkage, and dimension reduction applicable to large text corpora. With approaches in these fields being grounded in traditional statistical techniques, the need arises for frameworks whereby advanced NLP techniques such as topic modelling may be incorporated within classical methodologies. This paper provides a classical, supervised, statistical learning framework for prediction from text, using topic models as a data reduction method and the topics themselves as predictors, alongside typical statistical tools for predictive modelling. We apply this framework in a Social Sciences context (applied animal behaviour) as well as a Humanities context (narrative analysis) as examples of this framework. The results show that topic regression models perform comparably to their much less efficient equivalents that use individual words as predictors.Vanessa Glenny, Jonathan Tuke, Nigel Bean, Lewis Mitchel
Modeling BGP table fluctuations
No full textIn this paper we develop a mathematical model to capture BGP table fluctuations. This provides the necessary foundations to study short- and long-term routing table growth. We reason that this growth is operationally critical for network administrators who need to gauge the amount of memory to install in routers as well as being a potential deciding factor in determining when the Internet community will run out of IPv4 address space. We demonstrate that a simple model using a simple arrival process with heavy tailed service times is sufficient to reproduce BGP dynamics including the “spiky” characteristics of the original trace data. We derive our model using a classification technique that separates newly added or removed prefixes, short-term spikes and long-term stable prefixes. We develop a model of non-stable prefixes and show it has similar properties in their magnitude and duration to those observed in recorded BGP traces.Ashley Flavel, Matthew Roughan, Nigel Bean and Olaf Maenne
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
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