BibSonomyburst/user/jaeschkeBibSonomy RSS feed for /user/jaeschke2012-02-15T14:57:03+01:00http://www.bibsonomy.org/bibtex/287d6883ebd98e8810be45d7e7e4ade96/jaeschkejaeschke2012-02-13T12:52:23+01:002012 bookmarking collaborative folksonomy myown recommender social tagging <span class="authorEditorList"><a href="/author/Balby Marinho">L. Balby Marinho</a>, <a href="/author/Hotho">A. Hotho</a>, <a href="/author/Jäschke">R. Jäschke</a>, <a href="/author/Nanopoulos">A. Nanopoulos</a>, <a href="/author/Rendle">S. Rendle</a>, <a href="/author/Schmidt-Thieme">L. Schmidt-Thieme</a>, <a href="/author/Stumme">G. Stumme</a>, and <a href="/author/Symeonidis">P. Symeonidis</a> </span><em>SpringerBriefs in Electrical and Computer Engineering </em><em>Springer, </em>(<em>February 2012</em>)Mon Feb 13 12:52:23 CET 2012febSpringerBriefs in Electrical and Computer EngineeringRecommender Systems for Social Tagging Systems20122012 bookmarking collaborative folksonomy myown recommender social tagging Social Tagging Systems are web applications in which users upload resources (e.g., bookmarks, videos, photos, etc.) and annotate it with a list of freely chosen keywords called tags. This is a grassroots approach to organize a site and help users to find the resources they are interested in. Social tagging systems are open and inherently social; features that have been proven to encourage participation. However, with the large popularity of these systems and the increasing amount of user-contributed content, information overload rapidly becomes an issue. Recommender Systems are well known applications for increasing the level of relevant content over the “noise” that continuously grows as more and more content becomes available online. In social tagging systems, however, we face new challenges. While in classic recommender systems the mode of recommendation is basically the resource, in social tagging systems there are three possible modes of recommendation: users, resources, or tags. Therefore suitable methods that properly exploit the different dimensions of social tagging systems data are needed. In this book, we survey the most recent and state-of-the-art work about a whole new generation of recommender systems built to serve social tagging systems. The book is divided into self-contained chapters covering the background material on social tagging systems and recommender systems to the more advanced techniques like the ones based on tensor factorization and graph-based models.http://www.bibsonomy.org/bibtex/29694689a034cc02aae1e27114ca26a94/jaeschkejaeschke2012-02-06T17:42:47+01:00analysis concept discovery fca formal kdd knowledge survey <span class="authorEditorList"><a href="/author/Poelmans">Jonas Poelmans</a>, <a href="/author/Elzinga">Paul Elzinga</a>, <a href="/author/Viaene">Stijn Viaene</a>, and <a href="/author/Dedene">Guido Dedene</a> </span><em>Conceptual Structures: From Information to Intelligence, </em><em>volume 6208 of Lecture Notes in Computer Science, </em><em>Springer, </em><em>Berlin/Heidelberg, </em>(<em>2010</em>)Mon Feb 06 17:42:47 CET 2012Berlin/HeidelbergConceptual Structures: From Information to Intelligence139--153Lecture Notes in Computer ScienceFormal Concept Analysis in Knowledge Discovery: A Survey62082010analysis concept discovery fca formal kdd knowledge survey In this paper, we analyze the literature on Formal Concept Analysis (FCA) using FCA. We collected 702 papers published between 2003-2009 mentioning Formal Concept Analysis in the abstract. We developed a knowledge browsing environment to support our literature analysis process. The pdf-files containing the papers were converted to plain text and indexed by Lucene using a thesaurus containing terms related to FCA research. We use the visualization capabilities of FCA to explore the literature, to discover and conceptually represent the main research topics in the FCA community. As a case study, we zoom in on the 140 papers on using FCA in knowledge discovery and data mining and give an extensive overview of the contents of this literature.http://www.bibsonomy.org/bibtex/27d41d332cccc3e7ba8e7dadfb7996337/jaeschkejaeschke2012-02-06T13:47:57+01:002012 bookmarking challenge collaborative dc09 discovery folksonomy myown recommender rsdc08 social tagging <span class="authorEditorList"><a href="/author/Jäschke">Robert Jäschke</a>, <a href="/author/Hotho">Andreas Hotho</a>, <a href="/author/Mitzlaff">Folke Mitzlaff</a>, and <a href="/author/Stumme">Gerd Stumme</a> </span><em>Recommender Systems for the Social Web, </em><em>volume 32 of Intelligent Systems Reference Library, </em><em>Springer, </em><em>Berlin/Heidelberg, </em>(<em>2012</em>)Mon Feb 06 13:47:57 CET 2012Berlin/HeidelbergRecommender Systems for the Social Web65--87Intelligent Systems Reference LibraryChallenges in Tag Recommendations for Collaborative Tagging Systems3220122012 bookmarking challenge collaborative dc09 discovery folksonomy myown recommender rsdc08 social tagging Originally introduced by social bookmarking systems, collaborative tagging, or social tagging, has been widely adopted by many web-based systems like wikis, e-commerce platforms, or social networks. Collaborative tagging systems allow users to annotate resources using freely chosen keywords, so called tags . Those tags help users in finding/retrieving resources, discovering new resources, and navigating through the system. The process of tagging resources is laborious. Therefore, most systems support their users by tag recommender components that recommend tags in a personalized way. The Discovery Challenges 2008 and 2009 of the European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases (ECML PKDD) tackled the problem of tag recommendations in collaborative tagging systems. Researchers were invited to test their methods in a competition on datasets from the social bookmark and publication sharing system BibSonomy. Moreover, the 2009 challenge included an online task where the recommender systems were integrated into BibSonomy and provided recommendations in real time. In this chapter we review, evaluate and summarize the submissions to the two Discovery Challenges and thus lay the groundwork for continuing research in this area.http://www.bibsonomy.org/bibtex/223959c014b9b6d46c93f45cf68e52294/jaeschkejaeschke2012-02-02T14:43:39+01:00analysis concept fca formal triadic <span class="authorEditorList"><a href="/author/Wille">Rudolf Wille</a> </span><em>Order</em> <em>12(2):149--158</em> (<em>1995</em>)Thu Feb 02 14:43:39 CET 2012Order2149--158The Basic Theorem of triadic concept analysis121995analysis concept fca formal triadic Experiences with applications of concept lattices and the pragmatic philosophy founded by Ch. S. Peirce have suggested a triadic approach to formal concept analysis. It starts with the notion of a triadic context combining objects, attributes, and conditions under which objects may have certain attributes. The Basic Theorem of triadic concept analysis clarifies the class of structures which are formed by the triadic concepts of triadic contexts: These structures are exactly the complete trilattices up to isomorphism.http://www.bibsonomy.org/bibtex/200e49959d4e04d104a9109132ad8ed40/jaeschkejaeschke2012-01-25T19:43:37+01:00test <span class="authorEditorList"><a href="/author/van Oudenaarden">A. van Oudenaarden</a>, <a href="/author/van Oudenaarden">A van Oudenaarden</a>, and <a href="/author/The Economist Intelligence Unit"> The Economist Intelligence Unit</a> </span> (<em>2010</em>)Wed Jan 25 19:43:37 CET 2012Author Names Test Post2010test http://www.bibsonomy.org/bibtex/2e61bd0c26cc1c08cff22a8301d03044f/jaeschkejaeschke2012-01-24T12:21:50+01:00analysis citation science toread scientometrics <span class="authorEditorList"><a href="/author/Bollen">Johan Bollen</a>, <a href="/author/van de Sompel">Herbert van de Sompel</a>, <a href="/author/Hagberg">Aric Hagberg</a>, <a href="/author/Bettencourt">Luis Bettencourt</a>, <a href="/author/Chute">Ryan Chute</a>, <a href="/author/Rodriguez">Marko A. Rodriguez</a>, and <a href="/author/Balakireva">Lyudmila Balakireva</a> </span><em>PLoS ONE</em> <em>4(3):e4803</em> (<em>March 2009</em>)Tue Jan 24 12:21:50 CET 2012PLoS ONEmar3e4803Clickstream Data Yields High-Resolution Maps of Science42009analysis citation science toread scientometrics Background Intricate maps of science have been created from citation data to visualize the structure of scientific activity. However, most scientific publications are now accessed online. Scholarly web portals record detailed log data at a scale that exceeds the number of all existing citations combined. Such log data is recorded immediately upon publication and keeps track of the sequences of user requests (clickstreams) that are issued by a variety of users across many different domains. Given these advantages of log datasets over citation data, we investigate whether they can produce high-resolution, more current maps of science. Methodology Over the course of 2007 and 2008, we collected nearly 1 billion user interactions recorded by the scholarly web portals of some of the most significant publishers, aggregators and institutional consortia. The resulting reference data set covers a significant part of world-wide use of scholarly web portals in 2006, and provides a balanced coverage of the humanities, social sciences, and natural sciences. A journal clickstream model, i.e. a first-order Markov chain, was extracted from the sequences of user interactions in the logs. The clickstream model was validated by comparing it to the Getty Research Institute's Architecture and Art Thesaurus. The resulting model was visualized as a journal network that outlines the relationships between various scientific domains and clarifies the connection of the social sciences and humanities to the natural sciences. Conclusions Maps of science resulting from large-scale clickstream data provide a detailed, contemporary view of scientific activity and correct the underrepresentation of the social sciences and humanities that is commonly found in citation data.http://www.bibsonomy.org/bibtex/2bd589cc0b6fdfc74b5eea4262c46d3a4/jaeschkejaeschke2012-01-24T12:13:30+01:00analysis citation factor impact toread scientometrics <span class="authorEditorList"><a href="/author/Leydesdorff">Loet Leydesdorff</a> </span><em>Digital Libraries</em> (<em>2012</em>)Tue Jan 24 12:13:30 CET 2012Digital LibrariesAlternatives to the Journal Impact Factor: I3 and the Top-10% (or Top-25%?) of the Most-Highly Cited Papers1201.46382012analysis citation factor impact toread scientometrics Journal Impact Factors (IFs) can be considered historically as the first attempt to normalize citation distributions by using averages over two years. However, it has been recognized that citation distributions vary among fields of science and that one needs to normalize for this. Furthermore, the mean-or any central-tendency statistics-is not a good representation of the citation distribution because these distributions are skewed. Important steps have been taken to solve these two problems during the last few years. First, one can normalize at the article level using the citing audience as the reference set. Second, one can use non-parametric statistics for testing the significance of differences among ratings. A proportion of most-highly cited papers (the top-10% or top-quartile) on the basis of fractional counting of the citations may provide an alternative to the current IF. This indicator is intuitively simple, allows for statistical testing, and accords with the state of the art. Scientometrics, in presshttp://www.bibsonomy.org/bibtex/245374b975834248c0cd87022fc854e25/jaeschkejaeschke2012-01-20T10:30:56+01:00analysis concept fca formal ontology rdf semantic web <span class="authorEditorList"><a href="/author/d&#039;Aquin">Mathieu d&#039;Aquin</a>, and <a href="/author/Motta">Enrico Motta</a> </span><em>Proceedings of the sixth international conference on Knowledge capture, </em><em>page 121--128. </em><em>New York, NY, USA, </em><em>ACM, </em>(<em>2011</em>)Fri Jan 20 10:30:56 CET 2012New York, NY, USAProceedings of the sixth international conference on Knowledge capture121--128Extracting relevant questions to an RDF dataset using formal concept analysis2011analysis concept fca formal ontology rdf semantic web With the rise of linked data, more and more semantically described information is being published online according to the principles and technologies of the Semantic Web (especially, RDF and SPARQL). The use of such standard technologies means that this data should be exploitable, integrable and reusable straight away. However, once a potentially interesting dataset has been discovered, significant efforts are currently required in order to understand its schema, its content, the way to query it and what it can answer. In this paper, we propose a method and a tool to automatically discover questions that can be answered by an RDF dataset. We use formal concept analysis to build a hierarchy of meaningful sets of entities from a dataset. These sets of entities represent answers, which common characteristics represent the clauses of the corresponding questions. This hierarchy can then be used as a querying interface, proposing questions of varying levels of granularity and specificity to the user. A major issue is however that thousands of questions can be included in this hierarchy. Based on an empirical analysis and using metrics inspired both from formal concept analysis and from ontology summarization, we devise an approach for identifying relevant questions to act as a starting point to the navigation in the question hierarchy.http://www.bibsonomy.org/bibtex/2fda93dfcede4fba9008399dd29fb26d7/jaeschkejaeschke2012-01-12T16:15:25+01:00distributed replication synchronization <span class="authorEditorList"><a href="/author/Schütt">Thorsten Schütt</a>, <a href="/author/Schintke">Florian Schintke</a>, and <a href="/author/Reinefeld">Alexander Reinefeld</a> </span><em>International Conference on Computational Science, </em><em>volume 2657 of Lecture Notes in Computer Science, </em><em>Springer, </em><em>Berlin / Heidelberg, </em>(<em>2003</em>)Thu Jan 12 16:15:25 CET 2012Berlin / HeidelbergInternational Conference on Computational Science662--662Lecture Notes in Computer ScienceEfficient Synchronization of Replicated Data in Distributed Systems26572003distributed replication synchronization We present nsync, a tool for synchronizing large replicated data sets in distributed systems. nsync computes nearly optimal synchronization plans based on a hierarchy of gossip algorithms that take the network topology into account. Our primary design goals were maximum performance and maximum scalability. We achieved these goals by exploiting parallelism in the planning and the synchronization phase, by omitting transfer of unnecessary metadata, by synchronizing at a block level rather than a file level, and by using sophisticated compression methods. With its relaxed consistency semantic, nsync neither needs a master copy nor a quorum for updating distributed replicas. Each replica is kept as an autonomous entity and can be modified with the usual tools.http://www.bibsonomy.org/bibtex/277474654b2e57fc8eff45a0190294547/jaeschkejaeschke2012-01-12T16:09:53+01:00library oai repository synchronization <span class="authorEditorList"><a href="/author/Liu">Xiaoming Liu</a>, <a href="/author/Maly">Kurt Maly</a>, <a href="/author/Zubair">Mohammad Zubair</a>, and <a href="/author/Nelson">Michael L. Nelson</a> </span><em>Proceedings of the 3rd ACM/IEEE-CS joint conference on Digital libraries, </em><em>page 191--198. </em><em>Washington, DC, USA, </em><em>IEEE Computer Society, </em>(<em>2003</em>)Thu Jan 12 16:09:53 CET 2012Washington, DC, USAProceedings of the 3rd ACM/IEEE-CS joint conference on Digital libraries191--198Repository synchronization in the OAI framework2003library oai repository synchronization The Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) began as an alternative to distributed searching of scholarly eprint repositories. The model embraced by the OAI-PMH is that of metadata harvesting, where value-added services (by a "service provider") are constructed on cached copies of the metadata extracted from the repositories of the harvester's choosing. While this model dispenses with the well known problems of distributed searching, it introduces the problem of synchronization. Stated simply, this problem arises when the service provider's copy of the metadata does not match the metadata currently at the constituent repositories. We define some metrics for describing the synchronization problem in the OAI-PMH. Based on these metrics, we study the synchronization problem of the OAI-PMH framework and propose several approaches for harvesters to implement better synchronization. In particular, if a repository knows its update frequency, it can publish it in an OAI-PMH Identify response using an optional About container that borrows from RDF Site Syndication (RSS) Format.Repository synchronization in the OAI frameworkhttp://www.bibsonomy.org/bibtex/2ac2f370d6267ed2d9e8e81ae4d709735/jaeschkejaeschke2012-01-11T16:13:11+01:00bibliographic bibliometrics library <span class="authorEditorList"><a href="/author/Ayres">F. H. Ayres</a>, and <a href="/author/Ridley">J. M. Ridley</a> </span><em>Cataloging \&amp; Classification Quarterly</em> <em>44(1--2):113--130</em> (<em>2007</em>)Wed Jan 11 16:13:11 CET 2012Cataloging \& Classification Quarterly1--2113--130Twenty-Five Years of Bibliographic Control Research at the University of Bradford442007bibliographic bibliometrics library This article describes cooperation between Bradford University Library and the Department of Computing that has resulted in nine research projects over a twenty-five year period on various aspects of bibliographic control. It recounts the origins of the Universal Standard Bibliographic Code (USBC) and its development for the identification of both books and non-book material. It then describes various aspects of the projects including simulating the merging necessary to set up a national database, the cleaning of a database, its use in inter-library lending, and its application together with expert systems for the quality control of databases. The final project is BOPAC that has used modern technology to create faster and better access to a number of library catalogues worldwide and has demonstrated that authority control in its present form is not effective. http://www.bibsonomy.org/bibtex/267b105a941f0a557c6d457447625cbfb/jaeschkejaeschke2012-01-09T13:46:31+01:00recommender survey tag tagging <span class="authorEditorList"><a href="/author/Zhang">Zi-Ke Zhang</a>, <a href="/author/Zhou">Tao Zhou</a>, and <a href="/author/Zhang">Yi-Cheng Zhang</a> </span><em>Journal of Computer Science and Technology</em> <em>26(5):767--777</em> (<em>2011</em>)Mon Jan 09 13:46:31 CET 2012Journal of Computer Science and Technology5767--777Tag-Aware Recommender Systems: A State-of-the-Art Survey262011recommender survey tag tagging In the past decade, Social Tagging Systems have attracted increasing attention from both physical and computer science communities. Besides the underlying structure and dynamics of tagging systems, many efforts have been addressed to unify tagging information to reveal user behaviors and preferences, extract the latent semantic relations among items, make recommendations, and so on. Specifically, this article summarizes recent progress about tag-aware recommender systems, emphasizing on the contributions from three mainstream perspectives and approaches: network-based methods, tensor-based methods, and the topic-based methods. Finally, we outline some other tag-related studies and future challenges of tag-aware recommendation algorithms.http://www.bibsonomy.org/bibtex/2525493be3d705f9637a0b5ed0311549d/jaeschkejaeschke2012-01-02T14:13:06+01:00arduino toread <span class="authorEditorList"><a href="/author/Premeaux">Emery Premeaux</a>, and <a href="/author/Evans">Brian Evans</a> </span><em>Apress, </em>(<em>2011</em>)Mon Jan 02 14:13:06 CET 2012Arduino Projects to Save the World.2011arduino toread * The first Green Arduino book Walks the reader through complete environmental home projects Contains the first in-depth discussion on environmental sensors for beginners Gives hobbyists the power to make their homes green and future-proof Explains what to do with raw environmental data and how to use them in energy decision making Arduino Projects to Save the World shows that it takes little more than a few tools, a few wires and sensors, an Arduino board, and a bit of gumption to build devices that lower energy bills, help you grow our own food, monitor pollution in the air and in the ground, even warn you about earth tremors. Arduino Projects to Save the World introduces the types of sensors needed to collect environmental data—from temperature sensors to motion sensors. You'll see projects that deal with energy sources—from building your own power strip to running your Arduino board on solar panels so you can actually proceed to build systems that help, for example, to lower your energy bills. Once you have some data, it's time to put it to good use by publishing it online as you collect it; this book shows you how. The core of this book deals with the Arduino projects themselves: * Account for heat loss using a heat loss temperature sensor array that sends probes into every corner of your house for maximum measurement. * Monitor local seismic activity with your own seismic monitor. * Keep your Arduino devices alive in the field with a solar powered device that uses a smart, power-saving design. * Monitor your data and devices with a wireless radio device; place your sensors where you like without worrying about wires. * Keep an eye on your power consumption with a sophisticated power monitor that records its data wherever you like. Arduino Projects to Save the World teaches the aspiring green systems expert to build environmentally-sound, home-based Arduino devices. Saving the world, one Arduino at a time. http://www.bibsonomy.org/bibtex/2c360454b0f49b781ccbbe16840f54b35/jaeschkejaeschke2011-12-22T11:00:50+01:00analysis bibliometrics citation <span class="authorEditorList"><a href="/author/Thijs">Bart Thijs</a>, and <a href="/author/Glänzel">Wolfgang Glänzel</a> </span><em>Scientometrics</em> <em>66(1):71--80</em> (<em>2006</em>)Thu Dec 22 11:00:50 CET 2011Scientometrics171--80The influence of author self-citations on bibliometric meso-indicators. The case of european universities662006analysis bibliometrics citation In earlier studies by the authors, basic regularities of author self-citations have been analysed. These regularities are related to the ageing, to the relation between self-citations and foreign citations, to the interdependence of self-citations with other bibliometric indicators and to the influence of co-authorship on self-citation behaviour. Although both national and subject specific peculiarities influence the share of self-citations at the macro level, the authors came to the conclusion that - at this level of aggregation - there is practically no need for excluding self-citations. The aim of the present study is to answer the question in how far the influence of author self-citations on bibliometric meso-indicators deviates from that at the macro level, and to what extent national reference standards can be used in bibliometric meso analyses. In order to study the situation at the institutional level, a selection of twelve European universities representing different countries and different research profiles have been made. The results show a quite complex situation at the meso-level, therefore we suggest the usage of both indicators, including and excluding self-citations.http://www.bibsonomy.org/bibtex/2d23fb8f74f6e1623bc0a845df9d630f0/jaeschkejaeschke2011-12-22T10:49:57+01:00analysis bibliometrics citation <span class="authorEditorList"><a href="/author/Glänzel">Wolfgang Glänzel</a>, and <a href="/author/Thijs">Bart Thijs</a> </span><em>Scientometrics</em> <em>59(3):281--310</em> (<em>2004</em>)Thu Dec 22 10:49:57 CET 2011Scientometrics3281--310The influence of author self-citations on bibliometric macro indicators592004analysis bibliometrics citation In a recent paper the authors have studied the role of author self-citations within the process of documented scientific communication. Two important regularities such as the relative fast ageing of self-citations with respect to foreign citations and the “square-root law” characterising the conditional expectation of self-citations for given number of foreign citation have been found studying the phenomenon of author self-citations at the macro level. The goal of the present paper is to study the effect of author self-citations on macro indicators. The analysis of citation based indicators for 15 fields in the sciences, social sciences and humanities substantiates that at this level of aggregation there is no need for any revision of national indicators and the underlying journal citation measures in the context of excluding self-citations.http://www.bibsonomy.org/bibtex/24d0cb8db8cf90029b781872d0dc84624/jaeschkejaeschke2011-12-22T08:27:20+01:00drawing graph graphics graphviz visualization <span class="authorEditorList"><a href="/author/Gansner">Emden R. Gansner</a>, and <a href="/author/North">Stephen C. North</a> </span><em>Software Practice \&amp; Experience</em> <em>30(11):1203--1233</em> (<em>September 2000</em>)Thu Dec 22 08:27:20 CET 2011New York, NY, USASoftware Practice \& Experiencesep111203--1233An open graph visualization system and its applications to software engineering302000drawing graph graphics graphviz visualization We describe a package of practical tools and libraries for manipulating graphs and their drawings. Our design, which aimed at facilitating the combination of the package components with other tools, includes stream and event interfaces for graph operations, high-quality static and dynamic layout algorithms, and the ability to handle sizable graphs. We conclude with a description of the applications of this package to a variety of software engineering tools.http://www.bibsonomy.org/bibtex/2f022e60c5928e01c701d7ec539ec221b/jaeschkejaeschke2011-12-21T22:52:09+01:00bookmarking collaborative folkrank folksonomy ranking search tagging web pagerank <span class="authorEditorList"><a href="/author/Kim">Heung-Nam Kim</a>, and <a href="/author/El Saddik">Abdulmotaleb El Saddik</a> </span><em>Proceedings of the fifth ACM conference on Recommender systems, </em><em>page 45--52. </em><em>New York, NY, USA, </em><em>ACM, </em>(<em>2011</em>)Wed Dec 21 22:52:09 CET 2011New York, NY, USAProceedings of the fifth ACM conference on Recommender systems45--52Personalized PageRank vectors for tag recommendations: inside FolkRank2011bookmarking collaborative folkrank folksonomy ranking search tagging web pagerank This paper looks inside FolkRank, one of the well-known folksonomy-based algorithms, to present its fundamental properties and promising possibilities for improving performance in tag recommendations. Moreover, we introduce a new way to compute a differential approach in FolkRank by representing it as a linear combination of the personalized PageRank vectors. By the linear combination, we present FolkRank's probabilistic interpretation that grasps how FolkRank works on a folksonomy graph in terms of the random surfer model. We also propose new FolkRank-like methods for tag recommendations to efficiently compute tags' rankings and thus reduce expensive computational cost of FolkRank. We show that the FolkRank approaches are feasible to recommend tags in real-time scenarios as well. The experimental evaluations show that the proposed methods provide fast tag recommendations with reasonable quality, as compared to FolkRank. Additionally, we discuss the diversity of the top n tags recommended by FolkRank and its variants.http://www.bibsonomy.org/bibtex/2561772806731f6afcdc0c707e34662dd/jaeschkejaeschke2011-12-21T14:12:51+01:00power-law statistics <span class="authorEditorList"><a href="/author/Newman">M. E. J. Newman</a> </span>(<em>2004</em>)Wed Dec 21 14:12:51 CET 2011Power laws, Pareto distributions and Zipf's law2004power-law statistics When the probability of measuring a particular value of some quantity varies inversely as a power of that value, the quantity is said to follow a power law, also known variously as Zipf's law or the Pareto distribution. Power laws appear widely in physics, biology, earth and planetary sciences, economics and finance, computer science, demography and the social sciences. For instance, the distributions of the sizes of cities, earthquakes, solar flares, moon craters, wars and people's personal fortunes all appear to follow power laws. The origin of power-law behaviour has been a topic of debate in the scientific community for more than a century. Here we review some of the empirical evidence for the existence of power-law forms and the theories proposed to explain them. http://www.bibsonomy.org/bibtex/2acdeb6b7980b25477665939c191f1e40/jaeschkejaeschke2011-12-21T14:09:46+01:00generative model power-law statistics <span class="authorEditorList"><a href="/author/Mitzenmacher">M. Mitzenmacher</a> </span><em>Internet Mathematics</em> <em>1(2):226--251</em> (<em>2004</em>)Wed Dec 21 14:09:46 CET 2011Internet Mathematics2226--251A Brief History of Generative Models for Power Law and Lognormal Distributions 12004generative model power-law statistics Recently, I became interested in a current debate over whether file size distributions are best modelled by a power law distribution or a lognormal distribution. In trying to learn enough about these distributions to settle the question, I found a rich and long history, spanning many fields. Indeed, several recently proposed models from the computer science community have antecedents in work from decades ago. Here, I briefly survey some of this history, focusing on underlying generative models that lead to these distributions. One finding is that lognormal and power law distributions connect quite naturally, and hence, it is not surprising that lognormal distributions have arisen as a possible alternative to power law distributions across many fields. http://www.bibsonomy.org/bibtex/25dd9d0c2155f242393e63547d8a2347f/jaeschkejaeschke2011-12-21T08:52:42+01:00clustering community graph modularity network structure <span class="authorEditorList"><a href="/author/Newman">M. E. J. Newman</a> </span><em>Proceedings of the National Academy of Sciences</em> <em>103(23):8577--8582</em> (<em>2006</em>)Wed Dec 21 08:52:42 CET 2011Proceedings of the National Academy of Sciences238577--8582Modularity and community structure in networks1032006clustering community graph modularity network structure Many networks of interest in the sciences, including social networks, computer networks, and metabolic and regulatory networks, are found to divide naturally into communities or modules. The problem of detecting and characterizing this community structure is one of the outstanding issues in the study of networked systems. One highly effective approach is the optimization of the quality function known as “modularity” over the possible divisions of a network. Here I show that the modularity can be expressed in terms of the eigenvectors of a characteristic matrix for the network, which I call the modularity matrix, and that this expression leads to a spectral algorithm for community detection that returns results of demonstrably higher quality than competing methods in shorter running times. I illustrate the method with applications to several published network data sets.