Overview of content related to 'dns' http://www.ariadne.ac.uk/taxonomy/term/1263/all?article-type=&term=&organisation=&project=&author=&issue= RSS feed with Ariadne content related to specified tag en Abstract Modelling of Digital Identifiers http://www.ariadne.ac.uk/issue62/nicholas-et-al <div class="field field-type-text field-field-teaser-article"> <div class="field-items"> <div class="field-item odd"> <p><a href="/issue62/nicholas-et-al#author1">Nick Nicholas</a>, <a href="/issue62/nicholas-et-al#author2">Nigel Ward</a> and <a href="/issue62/nicholas-et-al#author3">Kerry Blinco</a> present an information model of digital identifiers, to help bring clarity to the vocabulary debates from which this field has suffered.</p> </div> </div> </div> <!-- v2, incorporating author review edits inc. lead-ins to bullet lists - 2010-02-12-19-30-rew--><!-- v2, incorporating author review edits inc. lead-ins to bullet lists - 2010-02-12-19-30-rew--><p>Discussion of digital identifiers, and persistent identifiers in particular, has often been confused by differences in underlying assumptions and approaches. To bring more clarity to such discussions, the PILIN Project has devised an abstract model of identifiers and identifier services, which is presented here in summary. Given such an abstract model, it is possible to compare different identifier schemes, despite variations in terminology; and policies and strategies can be formulated for persistence without committing to particular systems. The abstract model is formal and layered; in this article, we give an overview of the distinctions made in the model. This presentation is not exhaustive, but it presents some of the key concepts represented, and some of the insights that result.</p> <p>The main goal of the Persistent Identifier Linking Infrastructure (PILIN) project [<a href="#1">1</a>] has been to scope the infrastructure necessary for a national persistent identifier service. There are a variety of approaches and technologies already on offer for persistent digital identification of objects. But true identity persistence cannot be bound to particular technologies, domain policies, or information models: any formulation of a persistent identifier strategy needs to outlast current technologies, if the identifiers are to remain persistent in the long term.</p> <p>For that reason, PILIN has modelled the digital identifier space in the abstract. It has arrived at an ontology [<a href="#2">2</a>] and a service model [<a href="#3">3</a>] for digital identifiers, and for how they are used and managed, building on previous work in the identifier field [<a href="#4">4</a>] (including the thinking behind URI [<a href="#5">5</a>], DOI [<a href="#6">6</a>], XRI [<a href="#7">7</a>] and ARK [<a href="#8">8</a>]), as well as semiotic theory [<a href="#9">9</a>]. The ontology, as an abstract model, addresses the question 'what is (and isn't) an identifier?' and 'what does an identifier management system do?'. This more abstract view also brings clarity to the ongoing conversation of whether URIs can be (and should be) universal persistent identifiers.</p> <h2 id="Identifier_Model">Identifier Model</h2> <p>For the identifier model to be abstract, it cannot commit to a particular information model. The notion of an identifier depends crucially on the understanding that an identifier only identifies one distinct thing. But different domains will have different understandings of what things are distinct from each other, and what can legitimately count as a single thing. (This includes aggregations of objects, and different versions or snapshots of objects.) In order for the abstract identifier model to be applicable to all those domains, it cannot impose its own definitions of what things are distinct: it must rely on the distinctions specific to the domain.</p> <p>This means that information modelling is a critical prerequisite to introducing identifiers to a domain, as we discuss elsewhere [<a href="#10">10</a>]: identifier users should be able to tell whether any changes in a thing's content, presentation, or location mean it is no longer identified by the same identifier (i.e. whether the identifier is restricted to a particular version, format, or copy).</p> <p>The abstract identifier model also cannot commit to any particular protocols or service models. In fact, the abstract identifier model should not even presume the Internet as a medium. A sufficiently abstract model of identifiers should apply just as much to URLs as it does to ISBNs, or names of sheep; the model should not be inherently digital, in order to avoid restricting our understanding of identifiers to the current state of digital technologies. This means that our model of identifiers comes close to the understanding in semiotics of signs, as our definitions below make clear.</p> <p>There are two important distinctions between digital identifiers and other signs which we needed to capture. First, identifiers are managed through some system, in order to guarantee the stability of certain properties of the identifier. This is different to other signs, whose meaning is constantly renegotiated in a community. Those identifier properties requiring guarantees include the accountability and persistence of various facets of the identifier—most crucially, what is being identified. For digital identifiers, the <strong>identifier management system</strong> involves registries, accessed through defined services. An HTTP server, a PURL [<a href="#11">11</a>] registry, and an XRI registry are all instances of identifier management systems.</p> <p>Second, digital identifiers are straightforwardly <strong>actionable</strong>: actions can be made to happen in connection with the identifier. Those actions involve interacting with computers, rather than other people: the computer consistently does what the system specifies is to be done with the identifier, and has no latitude for subjective interpretation. This is in contrast with human language, which can involve complex processes of interpretation, and where there can be considerable disconnect between what a speaker intends and how a listener reacts. Because the interactions involved are much simpler, the model can concentrate on two actions which are core to digital identifiers, but which are only part of the picture in human communication: working out what is being identified (<em>resolution</em>), and accessing a representation of what is identified (<em>retrieval</em>).</p> <p>So to model managing and acting on digital identifiers, we need a concept of things that can be identified, names for things, and the relations between them. (Semiotics already gives us such concepts.) We also need a model of the systems through which identifiers are managed and acted on; what those systems do, and who requests them to do so; and what aspects of identifiers the systems manage.</p> <p>Our identifier model (as an ontology) thus encompasses:</p> <ul> <li><strong>Entities</strong> - including actors and identifier systems;</li> <li><strong>Relations</strong> between entities;</li> <li><strong>Qualities</strong>, as desirable properties of entities. Actions are typically undertaken in order to make qualities apply to entities.</li> <li><strong>Actions</strong>, as the processes carried out on entities (and corresponding to <strong>services</strong> in implementations);</li> </ul> <p>An individual identifier system can be modelled using concepts from the ontology, with an identifier system model.</p> <p>In the remainder of this article, we go through the various concepts introduced in the model under these classes. We present the concept definitions under each section, before discussing issues that arise out of them. <em>Resolution</em> and <em>Retrieval</em> are crucial actions for identifiers, whose definition involves distinct issues; they are discussed separately from other Actions. We briefly discuss the standing of HTTP URIs in the model at the end.</p> <p></p><p><a href="http://www.ariadne.ac.uk/issue62/nicholas-et-al" target="_blank">read more</a></p> issue62 feature article kerry blinco nick nicholas nigel ward d-lib magazine dest ietf oasis internet archive aggregation archives ark ascii browser cataloguing cool uri cordra curation data database digital object identifier dns document management doi e-learning ftp identifier infrastructure interoperability learning objects metadata mobile mobile phone namespace ontologies openurl persistent identifier purl repositories research rfc search technology semantic web semiotic service usage model uri url vocabularies wayback machine web browser xml xml namespaces Sat, 30 Jan 2010 00:00:00 +0000 editor 1528 at http://www.ariadne.ac.uk Embedding Web Preservation Strategies Within Your Institution http://www.ariadne.ac.uk/issue57/jisc-powr-2008-09-rpt <div class="field field-type-text field-field-teaser-article"> <div class="field-items"> <div class="field-item odd"> <p><a href="/issue57/jisc-powr-2008-09-rpt#author1">Christopher Eddie</a> reports on the third one-day workshop of the JISC-PoWR (Preservation of Web Resources) Project held at the University of Manchester on 12 September 2008.</p> </div> </div> </div> <p><a href="http://www.ariadne.ac.uk/issue57/jisc-powr-2008-09-rpt" target="_blank">read more</a></p> issue57 event report christopher eddie british library jisc ukoln university of bath university of oxford internet archive iwmw powr aggregation ajax archives blog browser content management curation data database dns facebook higher education intellectual property mp3 personalisation preservation research rss software twitter ulcc web 2.0 web development web resources wiki Thu, 30 Oct 2008 00:00:00 +0000 editor 1439 at http://www.ariadne.ac.uk Persistent Identifiers: Considering the Options http://www.ariadne.ac.uk/issue56/tonkin <div class="field field-type-text field-field-teaser-article"> <div class="field-items"> <div class="field-item odd"> <p><a href="/issue56/tonkin#author1">Emma Tonkin</a> looks at the current landscape of persistent identifiers, describes several current services, and examines the theoretical background behind their structure and use.</p> </div> </div> </div> <h2 id="What_Is_a_Persistent_Identifier_and_Why">What Is a Persistent Identifier, and Why?</h2> <p>Persistent identifiers (PIs) are simply maintainable identifiers that allow us to refer to a digital object – a file or set of files, such as an e-print (article, paper or report), an image or an installation file for a piece of software. The only interesting persistent identifiers are also persistently actionable (that is, you can "click" them); however, unlike a simple hyperlink, persistent identifiers are supposed to continue to provide access to the resource, even when it moves to other servers or even to other organisations.</p> <p><a href="http://www.ariadne.ac.uk/issue56/tonkin" target="_blank">read more</a></p> issue56 feature article emma tonkin ansi california digital library cnri darpa ietf iso niso oclc portico ukoln university of bath archives ark bibliographic data blog browser cataloguing content management cool uri data database digital library digital object identifier dissemination dns doi ftp handle system identifier infrastructure licence metadata multimedia naan name mapping authority namespace national library openurl persistent identifier preservation purl request for comments research rfc search technology software standardisation standards unicode uri url urn utf-8 video z39.88 Tue, 29 Jul 2008 23:00:00 +0000 editor 1413 at http://www.ariadne.ac.uk Distributed Services Registry Workshop http://www.ariadne.ac.uk/issue45/dsr-rpt <div class="field field-type-text field-field-teaser-article"> <div class="field-items"> <div class="field-item odd"> <p><a href="/issue45/dsr-rpt#author1">John Gilby</a> reports on the UKOLN/IESR two-day workshop at Scarman House, University of Warwick on 14-15 July 2005.</p> </div> </div> </div> <p>The number of available online digital collections is growing all the time and with this comes the need to discover these collections, both by machine (m2m) and by end-users. There is also a trend towards service-orientated architectures and a likely critical part of this will be service registries to assist with discovering services andtheir associated collections. UKOLN and the JISC Information Environment Services Registry Project (IESR) [<a href="#1">1</a>] organised a two-day workshop to look at some of the issues that are likely to be present in building a distributed approach.</p> <p><a href="http://www.ariadne.ac.uk/issue45/dsr-rpt" target="_blank">read more</a></p> issue45 event report john gilby cetis google jisc london school of economics mimas niso oai oclc oregon state university ukoln university of illinois university of liverpool university of oxford iesr jisc information environment access control application profile archives authentication collection description cordra creative commons data digital library dns dublin core e-learning e-science framework infrastructure intellectual property marc metadata oai-pmh open archives initiative openurl portal provenance repositories research rslp rss schema search technology service registry soap sru srw standards uddi url web services wiki xml xml schema z39.50 Sat, 29 Oct 2005 23:00:00 +0000 editor 1196 at http://www.ariadne.ac.uk World Wide Web Conference 2004 http://www.ariadne.ac.uk/issue40/www2004-rpt <div class="field field-type-text field-field-teaser-article"> <div class="field-items"> <div class="field-item odd"> <p><a href="/issue40/www2004-rpt#author1">Dave Beckett</a> reports on the international WWW2004 conference held in New York, 19-21 May 2004.</p> </div> </div> </div> <p><a href="http://www2004.org/">WWW2004</a> [<a href="#1">1</a>] was the 13th conference in the series of international World Wide Web conferences organised by the IW3C2 (International World Wide Web Conference Committee). This was the annual gathering of Web researchers and technologists to present the latest work on the Web and Web standardisation at the World Wide Web Consortium (W3C).</p> <p><a href="http://www.ariadne.ac.uk/issue40/www2004-rpt" target="_blank">read more</a></p> issue40 event report dave beckett amazon google ibm microsoft university of bristol university of southampton w3c algorithm blog browser cookie data dns hypertext lucene mobi mobile mobile phone ontologies open source owl privacy rdf repositories research rss search technology semantic web skos standardisation standards thesaurus uri web app web development wireless xml Thu, 29 Jul 2004 23:00:00 +0000 editor 1066 at http://www.ariadne.ac.uk ERPANET Seminar on Persistent Identifiers http://www.ariadne.ac.uk/issue40/erpanet-ids-rpt <div class="field field-type-text field-field-teaser-article"> <div class="field-items"> <div class="field-item odd"> <p><a href="/issue40/erpanet-ids-rpt#author1">Monica Duke</a> reports on a two-day training seminar on persistent identifiers held by ERPANET in Cork, Ireland over 17-18 June 2004.</p> </div> </div> </div> <h3 id="Day_One">Day One</h3> <ul> <li><a href="#introduction">Introduction</a></li> <li><a href="#welcome">Welcome and Keynote</a></li> <li><a href="#overview">Overview of Persistent Identifier initiatives</a></li> <li><a href="#urn">URN</a></li> <li><a href="#openurl">OpenURL - The Rough Guide</a></li> <li><a href="#uri">Info URIs</a></li> <li><a href="#dcmi">The DCMI Persistent Identifier Working Group</a></li> <li><a href="#cendi">The CENDI Report</a></li> <li><a href="#ark">ARK</a></li> <li><a href="#purls">PURLs</a></li> <li><a href="#handle">Overview of the Handle System</a></li> <li><a href="#doi">DOI</a></li> <p>&lt;</p> </ul><p><a href="http://www.ariadne.ac.uk/issue40/erpanet-ids-rpt" target="_blank">read more</a></p> issue40 event report monica duke ansi california digital library cnri codata dcc ietf iso jisc niso oai oclc the national archives ukoln university college cork university of bath w3c adl archives ark bibliographic data blog browser data dcmi digital curation digital library digital preservation digitisation dns doi dspace dublin core dublin core metadata initiative e-government e-learning file format framework further education handle system html identifier infrastructure interoperability learning objects lom metadata multimedia name mapping authority namespace national library oai-pmh onix ontologies open access openurl persistent identifier preservation prism privacy purl repositories research resource discovery schema scorm sfx software standards syndication uri url urn xml Thu, 29 Jul 2004 23:00:00 +0000 editor 1070 at http://www.ariadne.ac.uk Web Watch: A Survey Of Numbers of UK University Web Servers http://www.ariadne.ac.uk/issue24/web-watch <div class="field field-type-text field-field-teaser-article"> <div class="field-items"> <div class="field-item odd"> <p>How many web servers are there in the UK Higher Education community? <a href="/issue24/web-watch#author1">Brian Kelly</a> provides some answers.</p> </div> </div> </div> <p>How many web servers are there in use within the UK higher education community? What is the profile of server usage within the community - do most institutions take a distributed approach, running many servers, or is a centralised approach more popular? A WebWatch survey has been carried out recently in an attempt to answer these questions.</p> <p><a href="http://www.ariadne.ac.uk/issue24/web-watch" target="_blank">read more</a></p> issue24 tooled up brian kelly bournemouth university central school of speech and drama coventry university dartington college of arts de montfort university glasgow caledonian university glasgow school of art goldsmiths college imperial college london kings college london leeds metropolitan university london business school london school of economics manchester metropolitan university microsoft robert gordon university rose bruford college royal academy of music royal college of art royal college of music royal conservatoire of scotland royal holloway royal northern college of music royal veterinary college school of oriental and african studies sheffield hallam university south bank university surrey institute of art & design ukoln university college london university of bath university of cambridge university of london university of northumbria at newcastle university of oxford university of the west of england university of wales data database dns higher education search technology software url Thu, 22 Jun 2000 23:00:00 +0000 editor 715 at http://www.ariadne.ac.uk Performance and Security: Notes for System Administrators http://www.ariadne.ac.uk/issue8/unix-security <div class="field field-type-text field-field-teaser-article"> <div class="field-items"> <div class="field-item odd"> <p>Performance and Security - Notes for System Administrators: <a href="/issue8/unix-security#author1">Andy Powell</a> offers some hints and tips on the performance and security aspects of running electronic library services on UNIX based machines.</p> </div> </div> </div> <p>The eLib Technical Concertation day last November brought together techies from many of the eLib projects. (See Clare McClean's report in Ariadne issue 6 for more details <a href="#REF1">[1]</a>). A wide range of the technical issues associated with running electronic library services were discussed at the meeting but inevitably, given the time constraints, some of these were not covered in any great detail.</p> <p><a href="http://www.ariadne.ac.uk/issue8/unix-security" target="_blank">read more</a></p> issue8 tooled up andy powell ukoln university of bath w3c elib access control apache api archives bsd cache data dns ftp graphics html operating system passwords perl research rfc secure shell software solaris ssh Wed, 19 Mar 1997 00:00:00 +0000 editor 287 at http://www.ariadne.ac.uk Putting the UK on the Map http://www.ariadne.ac.uk/issue5/wolverhampton <div class="field field-type-text field-field-teaser-article"> <div class="field-items"> <div class="field-item odd"> <p><a href="/issue5/wolverhampton#author1">Peter Burden</a> of the University of Wolverhampton's School of Computing and Information Technology describes the history behind his clickable maps of the UK, an essential and well established (though unfunded) resource for quickly locating academic and research Web sites.</p> </div> </div> </div> <p>Many of you are probably familiar with the WWW active maps of UK academic resources operated by the University of Wolverhampton's School of Computing and Information Technology. If you're not point your WWW browser at <a href="http://www.scit.wlv.ac.uk/ukinfo/uk.map.html"> http://www.scit.wlv.ac.uk/ukinfo/uk.map.html</a> before going any further. I thought it might be of interest to Ariadne readers to hear how and why these maps were created.</p> <p><a href="http://www.ariadne.ac.uk/issue5/wolverhampton" target="_blank">read more</a></p> issue5 project update peter burden imperial college london ncsa ukoln university of cambridge university of edinburgh university of manchester university of oxford university of wolverhampton archives browser copyright data database dewey decimal dns free software ftp gif gopher graphics research software standards windows Wed, 18 Sep 1996 23:00:00 +0000 editor 145 at http://www.ariadne.ac.uk AC/DC http://www.ariadne.ac.uk/issue3/acdc <div class="field field-type-text field-field-teaser-article"> <div class="field-items"> <div class="field-item odd"> <p><a href="/issue3/acdc#author1">Dave Beckett</a> and <a href="/issue3/acdc#author2">Neil Smith</a> explain a search engine that only indexes sites in the .ac.uk domain.</p> </div> </div> </div> <h2 id="WWW_Crawlers_-_Why_A_New_One_">WWW Crawlers - Why A New One?&nbsp;</h2> <p>All the major WWW crawling programs such as <a href="http://www.altavista.digital.com">Alta Vista</a> (Digital), <a href="http://www.infoseek.com">InfoSeek</a>, <a href="http://www.lycos.com">Lycos</a>, <a href="http://www.webcrawler.com">Webcrawler</a>, <a href="http://www.excite.com/">Excite</a> etc. are based in the USA and collect their pages across the transatlantic link. There are two problems with the USA based services:</p> <p><a href="http://www.ariadne.ac.uk/issue3/acdc" target="_blank">read more</a></p> issue3 feature article dave beckett neil smith jisc university of kent w3c gnu apache archives cache data database dns dublin core free software ftp gopher higher education research search technology software standards url Sat, 18 May 1996 23:00:00 +0000 editor 72 at http://www.ariadne.ac.uk