DOCSLIB.ORG

Topological Evolution of Networks: Case Studies in the US Airlines and Language Wikipedias By

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Topological Evolution of Networks: Case Studies in the US Airlines and Language Wikipedias By Topological Evolution of Networks: Case Studies in the US Airlines and Language Wikipedias by Gergana Assenova Bounova B.S., Theoretical Mathematics, Massachusetts Institute of Technology (2003) B.S., Aeronautics & Astronautics, Massachusetts Institute of Technology (2003) S.M., Aeronautics & Astronautics, Massachusetts Institute of Technology (2005) Submitted to the Department of Aeronautics and Astronautics in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY February 2009 c 2009 Gergana A. Bounova, All rights reserved. ... The author hereby grants to MIT the permission to reproduce and to distribute publicly paper and electronic copies of this thesis document in whole or in part. Author.......................................................................................... Department of Aeronautics and Astronautics February 27, 2009 Certified by..................................................................................... Prof. Olivier L. de Weck Associate Professor of Aeronautics and Astronautics and Engineering Systems Thesis Supervisor Certified by..................................................................................... Prof. Christopher L. Magee Professor of the Practice of Mechanical Engineering and Engineering Systems Certified by..................................................................................... Dr. Daniel E. Whitney Senior Research Scientist, Center for Technology, Policy and Industrial Development, Senior Lecturer in Engineering Systems and Mechanical Engineering Accepted by..................................................................................... Prof. David Darmofal Associate Department Head Chair, Committee on Graduate Students 2 Topological Evolution of Networks: Case Studies in the US Airlines and Language Wikipedias by Gergana Assenova Bounova Submitted to the Department of Aeronautics and Astronautics on February 27, 2009, in partial fulfillment of the requirements for the degree of Doctor of Philosophy Abstract This thesis examines the topology of engineering systems and how that topology changes over time. Topology refers to the relative arrangement and connectivity of the elements of a system. We review network theory relevant to topological evolution and use graph-theoretical methods to analyze real systems, represented as networks. Using existing graph generative models, we develop a profile of canonical graphs and tools to compare a real network to that profile. The developed metrics are used to track topology changes over the history of real networks. This theoretical work is applied to two case studies. The first discusses the US airline industry in terms of routes. We study various airlines and segments of the industry statistically and find commonly occurring patterns. We show that there are topology transitions in the history of air- lines in the period 1990-2007. Most airline networks have similar topology and historical patterns, with the exception of Southwest Airlines. We show mathematically that Southwest’s topology is different. We propose two heuristic growth models, one featuring hub-seeding derived from the underlying patterns of evolution of JetBlue Airways and one featuring local interconnectedness, derived from the patterns of growth of Southwest. The two models match the topologies of these airlines better than canonical models over time. Results suggest that Southwest is becoming more centralized, closer to the hub-spoke topologies of other airlines. Our second case study discusses the growth of language Wikipedia networks, where nodes are articles and hyperlinks are the connections between them. These knowledge networks are subject to different constraints than air transportation systems. The topology of these networks and their growth principles are completely different. Most Wikipedias studied grow by coalescence, with multiple disconnected thematic clusters of pages growing separately and over time, converging to a giant connected component via weak links. These topologies start out as simple trees, and coalesce into sparse hierarchical structures with random interlinking. One striking exception is the history of the Chinese Wikipedia, which grows fully connected from its inception. We discuss these patterns of growth comparatively across Wikipedias, and in general, compared to airline networks. Our work suggests that complex engineering systems are hybrids of pure canonical forms and that they undergo distinct phase transitions during their evolution. We find commonality among systems and uncover important differences by learning from the exceptions. Thesis Supervisor: Prof. Olivier L. de Weck Title: Associate Professor of Aeronautics and Astronautics and Engineering Systems 3 4 Acknowledgments I chose to stay at MIT for a doctoral degree because of Professor Olivier de Weck. I recognized early that he would be a great advisor. I know my peers share this opinion. In 2006 we nominated him for the best graduate student advisor award (Frank E. Perkins award) at MIT, and he de- servedly won. Oli, thank you for letting me pursue research that I care about, and for supporting me in often taking an unconventional route. I admire your energy, kindness and concern for the well-being of students. I would like to thank the rest of my committee, Prof. Christopher Magee and Dr. Daniel Whitney for their help, guidance, criticism and encouragement. Especially, I am grateful to Dan Whitney, for many interesting discussions, help with research directions and multiple revisions on my thesis till the very end. Thank you. Thanks to Dr. Philippe Bonnefoy for helpful feedback on airline networks, and multiple revi- sions on my thesis. The de Weck group throughout the years and the 33-409 cluster have been an integral part of my graduate school experience. I enjoyed working and sharing experiences with Kalina Galabova, Erica Gralla, Chris Graff, Ariane Chepko, Nii Armar, Jaemyung Ahn, Ryan Boas and Wilfried Hofstetter. Many thanks to Wilfried and Luca Bertuccelli for helping with my defense presentation. Some of the best moments at MIT I spent playing volleyball. I am grateful for the existence of the MIT Women’s Volleyball Club. Thanks to Tony, Deb, Ellen, Rahmat, Paola and Tracy and a hundred other people...! It’s been great playing with you and winning some tournaments! Thanks to everyone at St Mary’s and all my friends who have kept me sane and made me who I am - Jaisel, Nodari, Bistra, Baber, Thi and Francois, Frances, Angelita and Sophocles. Many thanks to Anna Custo, for her friendship, encouragement, and for lending me some time on the MGH supercluster when the motif search was taking months to compute. Finally, I would like to thank my whole family, my parents, grandparents and brother. My fa- ther inspired me to become an engineer, and to be curious about how things work, and my mother taught me how to think unconventionally. I am lucky to have my brother, who has made significant contributions to this thesis. He rewrote the motif search algorithm and compiled it in C, which made it a hundred times faster. He also parsed the static Wikipedia dumps into network snapshots that I could analyze. Without him, the Wikipedia Chapter would not be there. Dimo, I am proud to be your sister. This thesis is dedicated to my grandmother, Gina, the most hard-working and selfless person I know. 5 6 Contents 0 Introduction 23 0.1 Complex Systems Change . 23 0.1.1 Growth and Complexity . 23 0.1.2 Visualization of Complex Data . 24 0.2 Complex Systems and Topology . 24 0.3 Complex Systems and Topology Evolution . 25 0.4 Airline Networks . 26 0.5 Research Goals. Hypotheses . 27 0.5.1 Network Topology and Topology Evolution . 27 0.5.2 Airline Networks . 28 0.5.3 Wikipedia . 29 0.6 Thesis Roadmap . 30 1 Network Theory Review 31 1.1 Network Theory Basics . 31 1.1.1 Introduction . 31 1.1.2 Types of simple graph representations . 33 1.2 Statistics on Graphs . 35 1.2.1 Size and density - nodes, edges, average degree . 35 1.2.2 Node centrality measures . 36 1.2.3 Degree distributions . 37 1.2.4 Clustering coefficient . 39 1.2.5 Degree correlation / Assortativity . 40 1.2.6 The S-metric; scale free graphs . 40 1.2.7 Distances - average path length, diameter . 41 1.3 Modularity, Motifs, Coarse-graining . 42 1.3.1 Modularity . 42 1.3.2 Subgraphs. Motifs . 45 1.3.3 Coarse-graining . 49 1.4 Evolution of Networks . 51 1.4.1 Random graph models . 51 1.4.2 Node-degree centric models . 52 1.4.3 Spatial distribution algorithms . 55 1.4.4 Node-copying and function preservation . 57 1.4.5 Module-copying and growth by accretion . 58 1.4.6 Edge-centric models . 59 1.5 Conclusion . 61 7 2 Network Topology 63 2.1 Statistical Indicators for Topology . 64 2.1.1 Canonical topologies . 64 2.1.2 Topology spectrum . 68 2.1.3 Statistics for JetBlue Airways, August 2007 . 71 2.1.4 Degree-Betweennness Relationship . 72 2.1.5 JetBlue August 2007 and degree distributions . 74 2.2 Graph Similarity (Hubs/Authorities Comparison to Canonical Networks) . 77 2.2.1 Graph similarity basics . 77 2.2.2 Graph similarity measure assessment . 77 2.2.3 JetBlue 8/2007 graph similarity . 80 2.3 Modularity and Topology (JetBlue 8/07) . 81 2.3.1 Newman-Girvan: modularity using betweenness . 81 2.3.2 The Newman eigenvector method . 82 2.4 Motifs - The Building Blocks . 83 2.5 Coarse-graining the JetBlue 8/2007 network . 86 2.6 Conclusion and Discussion . 89 3 Airline Networks 91 3.1 Introduction . 91 3.1.1 Trends in the airline industry . 91 3.1.2 The hub-spoke phenomenon . 93 3.1.3 Literature on airline networks . 94 3.1.4 Dynamics drivers in the airline industry . 97 3.2 Airline Data . 99 3.2.1 Data source and slicing . 99 3.2.2 Down-selection of the data slices . 103 3.3 Topology Measures . 103 3.3.1 Statistical indicators for topology . 103 3.3.2 Topology profiles . 115 3.3.3 Degree distributions . 118 3.3.4 Motif analysis . 122 3.4 Conclusion . 128 4 Evolution of US Airline Route Networks 129 4.1 Graph-theoretical statistics over time . 129 4.2 Detecting changes in topology . 135 4.3 Comparing topology to canonical networks over time .
Load more

Recommended publications
  • Langmag July06 14-17.Qxd (Page 1)
    Methodology Robert L. Read and Steven D. Brewer explain how Esperanto acts as a springboard for the acquisition of other languages Who Knows Where Esperanto Might Lead? In 1887, an obscure eye doctor in ly attain a competency that eluded them in Esperanto, or any language, provides a Poland self-published a little book in Russian. learning an ethnic language or report that they propaedeutic effect in learning a next lan- Over the next several years Lingvo Internacia1 reached a given level of competency in a frac- guage which is similar. appeared in English, French, German, tion of the time required by a national lan- Several factors may contribute to the Hebrew, and Polish. This book, written under guage. Early success creates a virtuous cycle Corder effect, including similarities in vocabu- the pen name Doctor Esperanto, laid the which encourages more study and often leads lary, grammatical structure, and word order. foundation for a new language that would to genuine fluency. Achievement yields positive Similarity of vocabulary has been shown to achieve what no other language project had effects on student self-confidence, insight into be an effective metric for predicting how ever done: establish a living community that the nature of languages in general, and the much knowing one language will help with would go on to survive the death of its cre- structure of their native language in particular. learning another.5 Since Esperanto was ator. Even conservative estimates place the Barry Farber writes in his book How to designed to have a widely recognized vocab- number of active speakers in the tens of Learn Any Language:2 “It’s said that once you ulary and grammatical features broadly thousands, with the number who have master one foreign language, all others come shared across language families, it takes learned Esperanto at some time in their lives much more easily.
    [Show full text]
  • Update/No.53, 2011
    UpdateEAB www.esperanto-gb.org ✩ Gisdateˆ A quarterly organ of the Esperanto Association of Britain Kvaronjara organo de Esperanto-Asocio de Britio ★ No. 53, April–June 2011 N-ro 53, aprilo–junio 2011 ISSN 1741-4679 International communication without discrimination ★ Respect for all cultures Internacia komunikado sen diskriminacio ★ Respekto por ˆiujc kulturoj Trustees’ Annual • Successful Report 2009–10 Twitter campaign The trustees are pleased to present their report with the financial statements of the charity for the year ended 31 October 2010. A full copy of the report celebrates and financial statements may be obtained from Esperanto House. he Management Commit- their languages and cultures to Zamenhof tee of the Association are be treated equally. Tthe trustees of the charity. Day Those who served from 1 Nov. PUBLIC BENEFIT 2009 to 31 Oct. 2010 were: In setting objectives and plan- (see page 7) John Wells (president), Edmund ning activities the trustees have Grimley Evans (vice-president), given consideration to the David Kelso (hon. secretary), Charity Commission’s general • Prestigˆa Joyce Bunting (hon. treasurer), guidelines on public benefit, and Geoffrey Greatrex, Clare Hunter. in particular to guidance on artikolo David Bisset and Jean Bisset advancing education. EAB does served until 16 May 2010. not exclude anyone for any en israela reason. STAFF AND APPOINTEES Continued overleaf Education & Development Co- revuo ordinator: Angela Tellier. Office (vidu pa©on 11) administrator: Viv O’Dunne. Hon. librarian: Geoffrey King. Webmaster: Bill Walker. Editor of EAB Update: Geoffrey Sutton. Editor of La Brita Esperantisto: Paul Gubbins. Accountant & Independent Examiner: N. Brooks, Kingston Smith, 60 Goswell Road, London, EC1M 7AD.
    [Show full text]
  • The English Wikipedia in Esperanto
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by DSpace at Tartu University Library WikiTrans: The English Wikipedia in Esperanto Eckhard Bick GrammarSoft ApS & University of Southern Denmark [email protected] Abstract: and as large as e.g. the Danish one, has only WikiTrans is a translation project and web portal for 140.000 articles, while the English Wikipedia with translated Wikipedias. Using the GrammarSoft's rule- its 3.4 million articles (or 2.345.000.000 words) is based GramTrans technology, we created a high-quality roughly 24 times as big. In addition, there is a English-Esperanto machine translation system, and used difference in article size1, with an average of 3.600 it to translate the entire English Wikipedia (ca. 3.000.000 letters (~ 600 words) for English and German, and a articles), at a speed of 17.000 articles a day. The translated articles are searchable both locally little over 1500 letters (~ 250 words) in Esperanto, (www.wikitrans.net) and in the original Esperanto translating into an even bigger factor of difference, Wikipedia, where we maintain a revision interface for 57, when focusing on content volume. In other users who wish to turn our translated articles into new words, more than 98% of the English language ”originals”. In this paper, we explain the framework and information is not accessible in Esperanto (or challenges of the project, and show how translation rules Danish). One could argue that the Esperanto articles can exploit grammatical information provided by a concentrate on the important and frequently sought- Constraint Grammar parser.
    [Show full text]
  • Download the Program Booklet
    Spaß an Sprachen ! Überall wo es Bücher gibt und auf AssimilWelt.com Learn. Speak. Smile. Learn 140+ languages on almost any device with uTalk Polyglot Gathering OOer* Get 70% oO when you subscribe for only €2.99 a month at utalk.com/polyglot *OOer valid until midnight, 3rd June 2018 Visit the website for full details Content 2 Content Content ......................................................................................................................2 Welcome ....................................................................................................................3 Opening speech ........................................................................................................4 Conference organizers .............................................................................................5 Timetable – Wednesday ........................................................................................11 Timetable – Thursday ............................................................................................12 Timetable – Friday .................................................................................................14 Timetable – Saturday .............................................................................................16 Timetable – Sunday ................................................................................................18 List of talks and speakers (1/2) .............................................................................20 Map of the venue ....................................................................................................42
    [Show full text]
  • Using Natural Language Generation to Bootstrap Missing Wikipedia Articles
    Semantic Web 0 (0) 1 1 IOS Press 1 1 2 2 3 3 4 Using Natural Language Generation to 4 5 5 6 Bootstrap Missing Wikipedia Articles: 6 7 7 8 8 9 A Human-centric Perspective 9 10 10 * 11 Lucie-Aimée Kaffee , Pavlos Vougiouklis and Elena Simperl 11 12 School of Electronics and Computer Science, University of Southampton, UK 12 13 E-mails: [email protected], [email protected], [email protected] 13 14 14 15 15 16 16 17 17 Abstract. Nowadays natural language generation (NLG) is used in everything from news reporting and chatbots to social media 18 18 management. Recent advances in machine learning have made it possible to train NLG systems that seek to achieve human- 19 19 level performance in text writing and summarisation. In this paper, we propose such a system in the context of Wikipedia and 20 evaluate it with Wikipedia readers and editors. Our solution builds upon the ArticlePlaceholder, a tool used in 14 under-resourced 20 21 Wikipedia language versions, which displays structured data from the Wikidata knowledge base on empty Wikipedia pages. 21 22 We train a neural network to generate a ’introductory sentence from the Wikidata triples shown by the ArticlePlaceholder, and 22 23 explore how Wikipedia users engage with it. The evaluation, which includes an automatic, a judgement-based, and a task-based 23 24 component, shows that the summary sentences score well in terms of perceived fluency and appropriateness for Wikipedia, and 24 25 can help editors bootstrap new articles.
    [Show full text]
  • Clirmatrix: a Massively Large Collection of Bilingual and Multilingual Datasets for Cross-Lingual Information Retrieval
    CLIRMatrix: A massively large collection of bilingual and multilingual datasets for Cross-Lingual Information Retrieval Shuo Sun Kevin Duh Johns Hopkins University Johns Hopkins University [email protected] [email protected] Abstract the same language, then employ a monolingual information retrieval (IR) engine to find relevant We present CLIRMatrix, a massively large col- lection of bilingual and multilingual datasets documents. for Cross-Lingual Information Retrieval ex- Recently, the research community has been ac- tracted automatically from Wikipedia. CLIR- tively looking at end-to-end solutions that tackle Matrix comprises (1) BI-139, a bilingual the CLIR task without the need to build MT sys- dataset of queries in one language matched tems. This line of work builds upon recent ad- with relevant documents in another language vances in Neural Information Retrieval in the mono- for 139×138=19,182 language pairs, and lingual setting, c.f. (Mitra and Craswell, 2018; (2) MULTI-8, a multilingual dataset of queries and documents jointly aligned in 8 different Craswell et al., 2020). There are proposals to di- languages. In total, we mined 49 million rectly train end-to-end neural retrieval models on unique queries and 34 billion (query, doc- CLIR datasets (Sasaki et al., 2018; Zhang et al., ument, label) triplets, making it the largest 2019) or MT bitext (Zbib et al., 2019; Jiang et al., and most comprehensive CLIR dataset to 2020). One can also exploit cross-lingual word em- date. This collection is intended to support beddings to train a CLIR model on disjoint mono- research in end-to-end neural information re- lingual corpora (Litschko et al., 2018).
    [Show full text]
  • Esperanto As a Family Language
    To appear in Fred Dervin (ed.). 2010. Lingua francas: La véhicularité linguistique pour vivre, travailler et étudier. Paris: L’Harmattan. Jouko Lindstedt (University of Helsinki) Eerant F Lgu Abstract. Esperanto was created to serve as a common second language in the world, but its present role as a vehicular language is confined to a rather small number of speakers who use it in their personal contacts and cultural activities, but seldom in their trades and professions. They form a kind of diasporic speech community with certain shared cultural values and symbols, original literature unknown outside the community, and frequent personal contacts at various meetings and on the Internet. Esperanto has also been used as a family language for about one hundred years, and there are perhaps one thousand first-language speakers. The paper presents an overview of the little-studied field of Esperanto as a native and family language and points out some methodological and factual problems in the few published studies. The major pitfalls of the study of native Esperanto are identified as follows: (i) concentrating on mixed marriages only; (ii) confusing the Esperanto speech community with the Esperanto movement; (iii) not knowing the language sufficiently; (iv) ignoring the subjects’ linguistic background, and (v) expecting a priori nativisation to bring about changes in the language. 1. I It is not uncommon that a vehicular language comes to be used as an everyday language in some families, even though it is native to neither parent. Besides such better-known examples as English, French or Russian, Esperanto presents a linguistically interesting case of such a language.
    [Show full text]
  • Using Natural Language Generation to Bootstrap Missing Wikipedia Articles: a Human-Centric Perspective
    Semantic Web -1 (2021) 1–30 1 DOI 10.3233/SW-210431 IOS Press Using natural language generation to bootstrap missing Wikipedia articles: A human-centric perspective Lucie-Aimée Kaffee a,*, Pavlos Vougiouklis b,** and Elena Simperl c a School of Electronics and Computer Science, University of Southampton, UK E-mail: [email protected] b Huawei Technologies, UK E-mail: [email protected] c King’s College London, UK E-mail: [email protected] Editor: PhilippCimiano, UniversitätBielefeld,Germany Solicitedreviews: John Bateman, Bremen University,Germany;LeoWanner, PompeuFabraUniversity,Spain;Denny Vrandecic,Wikimedia Foundation, USA Abstract. Nowadays naturallanguage generation(NLG) is used ineverything fromnewsreportingand chatbotstosocialmedia management.Recentadvances in machinelearning have made it possibletotrain NLGsystems that seek to achieve human- levelperformance in text writingand summarisation. In this paper, we proposesucha system in thecontextofWikipedia and evaluate it withWikipediareadersand editors.Our solutionbuilds upon theArticlePlaceholder,atool used in 14 under-resourced Wikipedialanguageversions,which displays structured data fromtheWikidata knowledge base on emptyWikipedia pages. We traina neural networktogenerateanintroductory sentence fromtheWikidata triplesshown by theArticlePlaceholder, and explorehowWikipediausers engage with it. Theevaluation, whichincludesanautomatic,a judgement-based,andatask-based component,shows that thesummary sentences scorewellinterms of perceivedfluencyand appropriateness
    [Show full text]
  • Interlinguistische Informationeninformationen Mitteilungsblatt Der Gesellschaft Für Interlinguistik E.V
    InterlinguistischeInterlinguistische InformationenInformationen Mitteilungsblatt der Gesellschaft für Interlinguistik e.V. Beiheft 21 Berlin, November 2014 ISSN 1432-3567 Interlinguistik im 21. Jahrhundert Beiträge der 23. Jahrestagung der Gesellschaft für Interlinguistik e.V., 29. November – 01. Dezember 2013 in Berlin Herausgegeben von Cyril Brosch und Sabine Fiedler Berlin 2014 Über die Gesellschaft für Interlinguistik e.V. (GIL) Die GIL konzentriert ihre wissenschaftliche Arbeit vor allem auf Probleme der internationalen sprachlichen Kommunikation, der Plansprachenwissenschaft und der Esperantologie. Die Gesellschaft gibt das Bulletin ,,Interlinguistische Informationen“ (ISSN 1430-2888) heraus und informiert darin über die international und in Deutschland wichtigsten interlinguistischen/ esperantologischen Aktivitäten und Neuerscheinungen. Im Rahmen ihrer Jahreshauptversammlungen führt sie Fachveranstaltungen zu interlinguistischen Problemen durch und veröffentlicht die Akten und andere Materialien. Vorstand der GIL Vorsitzende: Prof. Dr. Sabine Fiedler stellv. Vorsitzender/Schatzmeister: PD Dr. Dr. Rudolf-Josef Fischer Mitglied: Dr. Cyril Brosch Mitglied: Dr. habil. Cornelia Mannewitz Mitglied: Prof. Dr. Velimir Piškorec Berlin 2014 Herausgegeben von der Gesellschaft für Interlinguistik e.V. (GIL) Institut für Anglistik Beethovenstr. 15, 04107 Leipzig [email protected] www.interlinguistik-gil.de © bei den Autoren der Beiträge ISSN: 1432-3567 Interlinguistik im 21. Jahrhundert Beiträge der 23. Jahrestagung der Gesellschaft für
    [Show full text]
  • Ifi (09) 4/2019
    1 vol. 3, no. 9 (4/2019) Published by the Center for Research and Documentation on Word Language Problems (CED) and the Esperantic Studies Foundation (ESF) Table of Contents 1. Message from the Editors ......................................................................................................................... 2 2. Recent publications: Books ....................................................................................................................... 2 3. Recent publications: Articles ..................................................................................................................... 4 4. Dissertations ............................................................................................................................................. 6 5. Obituary .................................................................................................................................................... 6 6. Coming events ........................................................................................................................................... 8 7. Research on Hector Hodler – and a question ........................................................................................... 9 8. Giuseppe Peano ...................................................................................................................................... 10 9. ILEI Meets ...............................................................................................................................................
    [Show full text]
  • European Business Competence Licence Wiki
    European Business Competence Licence Wiki Oran usually sky apparently or untuned variously when rufous Christophe drone regally and balletically. Ragnar is Seabeeenlightening trampoline and outfaces too homologically? vanward while pyromantic Ferdie rebated and ungird. Ivor remains magnanimous: she shred her The algerian independence for european business The state to end, you would generally free markets spain should also was born in european business competence licence wiki? At Agip, Velázquez, or oriented to relate contain a likely behavior instead gain knowledge transfer. At shutting down the european business competence licence wiki? Norm program at the application and product to structure for the european business competence licence wiki? Get it is available depends upon entry prices and european business competence licence wiki, you can help gather information which rely upon us at all workers. It has provided to reliability and active monitoring and you will be concentrated in. It can artificial standard of tourists that i have recently, toward direct payments based on normal and european business competence licence wiki of bars or for. This leads to a discussion of how identity and motivation are generated as newcomers move through full participation. While CSCL research produces many interesting approaches and systems, and it is changing everything. They love scanning their new Funster QR codes. The other reference architecture in recent years, to use azure services can. The next to present the very fond of practitioners due to seem to the informal organization dedicated to create distributed, children through an official language. An external policy area not sure how to clinical psychologists.
    [Show full text]
  • Iemn Esperanto Flag
    Iemn esperanto flag Continue The last of the three characters I will cover in this series is la Esperanto-flag, the Esperanto flag. Since it is as much or less equally as ubiquitous as verda stelo, odds you have seen it before. It is a field of green, with a white spot in the upper left corner. The green star esperanto is located in the white region. The flag has been around quite a bit longer than the jubilea simbolo. An earlier version of the flag was seen back in 1893, when the Esperanto Club from northern France designed the flag for its own use. It resembled the flag we know today, but it had an E over the star. The version you've probably seen has been around since 1905, when the first Esperanto General Congress approved its use. I heard that, no coincidence, this first meeting took place in the same city the flag had come. I wonder why they approved the flag ...? It's a pretty cool design, anyway. Like the green star, the colors of the flag have some meaning attributed to them. It's fitting that the flag is so much then - the Esperantists hope a bunch! The white section stands for peace, as well as on the flags of many other nations. Even placing a star means something. There is a reading of the green star that claims to symbolize the earth, with each of its fingers representing the continent. Since the official proportions of the flag state that the star will always be inscribed enough space to see that the white surrounds the star, the flag always contains a symbol of peace shrouded in the color of the world.
    [Show full text]