most recent 30 from http://www.semanticoverflow.com 2010-07-31T08:20:06Z http://www.semanticoverflow.com/feeds/user/56 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://www.semanticoverflow.com/questions/1300/has-anyone-produced-a-mapping-of-annotated-tweets-to-rdf/1320#1320 Ian Davis 2010-07-14T16:43:09Z 2010-07-14T16:43:09Z

<p>Take a look at <a href="http://semantictweet.com/" rel="nofollow">SemanticTweet.com</a> which produces an RDF version of any Twitter profile.</p>

http://www.semanticoverflow.com/questions/1092/pointers-to-binary-rdf Ian Davis 2010-06-26T18:14:53Z 2010-07-13T14:54:29Z

<p>Has anyone done any evaluation or research into binary RDF using technologies such as protocol buffers, thrift or plain ASN.1?</p>

http://www.semanticoverflow.com/questions/1095/alternatives-to-owlsameas-for-linked-data Ian Davis 2010-06-27T02:27:37Z 2010-07-12T11:46:05Z

<p>Many people have stated that owl:sameAs is problematic because it is being (ab)used without regard for its strong semantics. </p> <p>SKOS defines the following:</p> <ul> <li>skos:closeMatch</li> <li>skos:exactMatch</li> <li>skos:broadMatch</li> <li>skos:narrowMatch</li> <li>skos:relatedMatch</li> </ul> <p>These seem useful and could be a basis for replacing owl:sameAs but what other predicates should exist?</p> <p><strong>Note: this is not the same question as <a href="http://www.semanticoverflow.com/questions/312/mapping-ontologies-are-there-alternatives-to-owlsameas" rel="nofollow">http://www.semanticoverflow.com/questions/312/mapping-ontologies-are-there-alternatives-to-owlsameas</a> since that is about ontology mapping and my question is about instance data.</strong></p>

http://www.semanticoverflow.com/questions/1175/should-we-seed-this-site-with-faqs Ian Davis 2010-07-05T13:14:44Z 2010-07-12T11:30:40Z

<p>Should we seed semantic overflow with FAQs and model answers to help newbies?</p>

http://www.semanticoverflow.com/questions/1229/fips-country-codes-in-rdf Ian Davis 2010-07-09T09:02:14Z 2010-07-09T10:41:17Z

<p>Does anyone know of a conversion of the FIPS country codes to RDF, ideally linked in to dbpedia and geonames?</p>

http://www.semanticoverflow.com/questions/1071/visualisation-toolkits-for-rdf Ian Davis 2010-06-24T22:05:36Z 2010-07-06T16:57:11Z

<p>I would like to collect a list of visualisation toolkits that can work with RDF. I know there are many general purpose ones that can be adapted but are there any that are targetting RDF natively via SPARQL for example?</p> <p>(This is a community wiki question so hopefully we can build a list of toolkist here)</p>

http://www.semanticoverflow.com/questions/1130/good-compression-algorithms-for-uris Ian Davis 2010-06-29T09:34:35Z 2010-07-03T16:37:56Z

<p>What's the best compression algorithm for URIs that takes into the account the URI syntax. I remember that the WAP specifications had a compression algorithms with tokens for "http://", "www", ".com" etc. I'm looking for something that achieves better results than simply gzipping each URI.</p>

http://www.semanticoverflow.com/questions/1107/why-is-it-necessary-to-split-reasoning-into-t-box-and-a-box Ian Davis 2010-06-27T15:15:39Z 2010-07-01T14:17:40Z

<p>What are the theoretical underpinnings of the T-Box/A-Box split? It seems divorced from reality to have the description of the world separate from the world itself. Naively I have heard it said that the situation is similar to the the first-order/second-order logic divide where second order logic can talk about the logical propositions themselves. Is that a correct analogy? </p>

http://www.semanticoverflow.com/questions/1092/pointers-to-binary-rdf/1129#1129 Ian Davis 2010-06-29T09:29:35Z 2010-06-29T09:29:35Z

<p>Answering my own question, Talis use Thrift with compressed ntriple payloads but I don't count this as a binary serialisation of the RDF model.</p>

http://www.semanticoverflow.com/questions/1087/generating-documentation-from-rdfs-and-or-owl-vocabularies/1111#1111 Ian Davis 2010-06-27T16:47:46Z 2010-06-27T16:47:46Z

<p>In the past I have used an <a href="http://vocab.org/2004/03/toolchain/vocab-html-docs.xsl" rel="nofollow">XSLT stylesheet</a> to produce HTML from RDF/XML. You can see an example of this in use at <a href="http://vocab.org/aiiso-roles/schema" rel="nofollow">http://vocab.org/aiiso-roles/schema</a></p> <p>More recently I use my own <a href="http://code.google.com/p/paget/" rel="nofollow">Paget</a> framework to produce documentation like <a href="http://vocab.org/bio/0.1/" rel="nofollow">http://vocab.org/bio/0.1/</a></p>

http://www.semanticoverflow.com/questions/1100/what-is-ontology-hijacking/1110#1110 Ian Davis 2010-06-27T16:40:26Z 2010-06-27T16:40:26Z

<p>I wrote a post called <a href="http://blog.iandavis.com/2009/09/linked-data-spam-vectors" rel="nofollow">Linked Data Spam Vectors</a> which came up with the following techniques for injecting misleading or unrequested information into RDF:</p> <ul> <li>False Labelling</li> <li>Misdirection</li> <li>Schema Pollution</li> <li>Identity Assumption</li> <li>Bait and Switch</li> <li>Data URI Embedding</li> </ul> <p>Perhaps I need to expand that list to include Ontology Hijacking, i.e. the practice of redefining popular ontology terms so that the attackers information will be conveyed to the consumer.</p>

http://www.semanticoverflow.com/questions/1105/owl-dl-compliance-why-redefining-existing-concepts-propeties-in-own-ontology/1106#1106 Ian Davis 2010-06-27T15:07:51Z 2010-06-27T15:07:51Z

<p>Actually I think it is important to be able to redefine other ontology terms for your own purposes. This is essential for decentralising authorship and publication of ontologies. Each ontology provider needs to ensure that what they create is consistent and has the computational requirements they require. They can't wait to convince every other ontology author to do the same.</p> <p>Basically when you redefine other ontology's terms in your own ontology you are stating: "If you want to work with my ontology and with instance data that has these terms in then these are the additional constraints that are necessary for compatibility". </p>

http://www.semanticoverflow.com/questions/448/what-are-microsofts-offerings-in-the-semantic-world/1091#1091 Ian Davis 2010-06-26T16:40:11Z 2010-06-26T16:40:11Z

<p>A number of years back I wrote Spiral RDF but it is not currently maintained:</p> <p><a href="http://code.google.com/p/spiralrdf/" rel="nofollow">http://code.google.com/p/spiralrdf/</a></p>

http://www.semanticoverflow.com/questions/1070/tools-for-sdmx-rdf Ian Davis 2010-06-24T22:02:08Z 2010-06-25T06:27:43Z

<p>Are there any tools for generating SDMX RDF from excel spreadsheets?</p>

http://www.semanticoverflow.com/questions/836/use-a-custom-datatype-or-a-property-for-approximate-dates Ian Davis 2010-04-30T16:20:38Z 2010-06-10T21:58:40Z

<p>I have a set of genealogical data that includes some vague/uncertain dates. For example, I may know that someone was born in May 1750 but not the exact day, or I may know they were born some time in the decade of the 1750s, or circa 1750 (meaning some years either side of it).</p> <p>Dublin Core have been looking at this area for a while and have a comprehensive set of requirements (http://dublincore.org/datewiki/DateRequirements) but no recommendation.</p> <p>My question is should I represent these kinds of dates using specific properties (e.g. ex:approximateDate) or with a datatype with a particular syntax?</p>

http://www.semanticoverflow.com/questions/336/what-is-a-convenient-method-of-shopping-for-rdfs-owl-vocabularies/910#910 Ian Davis 2010-05-21T18:48:01Z 2010-05-21T18:48:01Z

<p>I created <a href="http://schemapedia.com" rel="nofollow">Schemapedia</a> to help people find vocabularies and schemas.</p>

http://www.semanticoverflow.com/questions/864/linked-data-mesh-medical-subject-headings/865#865 Ian Davis 2010-05-07T13:18:19Z 2010-05-07T13:18:19Z

<p>You can find a SKOS version of MeSH at the Neurocommons project: <a href="http://neurocommons.org/page/Bundles/mesh/mesh-skos" rel="nofollow">http://neurocommons.org/page/Bundles/mesh/mesh-skos</a></p>

http://www.semanticoverflow.com/questions/859/best-way-to-convert-rdf-xml-file-to-pojos/860#860 Ian Davis 2010-05-06T19:32:39Z 2010-05-06T19:32:39Z

<p><a href="https://sommer.dev.java.net/sommer/index.html" rel="nofollow">Sommer</a> has a good reputation for POJO to RDF mapping.</p> <p>It uses annotations to map the POJO. One of the examples on that page looks like:</p> <pre><code>@rdf(foaf + "Agent") public class Agent { public static final String foaf = "http://xmlns.com/foaf/0.1/"; //field declarations @rdf(foaf + "mbox") private Collection&lt;URI&gt; mboxes; @rdf(foaf + "mbox_sha1sum") private Collection&lt;String&gt; mbox_sha1sums; @rdf(foaf + "jabberID") private String jabberId; @rdf(foaf + "aimChatID") private String aimChatId; ... } </code></pre>

http://www.semanticoverflow.com/questions/854/is-a-political-state-a-foaforganization Ian Davis 2010-05-05T23:50:50Z 2010-05-06T04:09:09Z

<p>foaf:Organization is defined as: "a kind of Agent corresponding to social institutions such as companies, societies etc."</p> <p>Does this extend to political/sovereign states as described by <a href="http://en.wikipedia.org/wiki/Sovereign_state" rel="nofollow">http://en.wikipedia.org/wiki/Sovereign_state</a></p>

http://www.semanticoverflow.com/questions/10/semantic-search-ranking/62#62 Ian Davis 2009-11-02T14:29:44Z 2010-05-04T21:04:31Z

<p>Tagging of content for search engine ranking should just be about following the best practice of POSH and writing relevant useful content. The semantic web isn't really about search at all so your question isn't easily answerable. Search is about looking for a document or page that contains the answer you are looking for. The semantic web is more about providing the actual answer to your question or providing assistance in making decisions about something.</p> <p>To understand the difference suppose you were trying to find the date a particular book was published. You could use a search engine to find a web page that you would read to learn the answer. The semantic web aims to allow you to ask your question and get the answer directly without having to scan through a web page.</p> <p>Update: Google state that rich snippets do <strong>not</strong> influence search rankings. See <a href="http://www.google.com/support/webmasters/bin/answer.py?hl=en&amp;answer=99170" rel="nofollow">http://www.google.com/support/webmasters/bin/answer.py?hl=en&amp;answer=99170</a></p>

http://www.semanticoverflow.com/questions/729/how-would-you-implement-the-symmetric-concise-bounded-description-scbd-using-ma/851#851 Ian Davis 2010-05-04T20:52:14Z 2010-05-04T20:52:14Z

<p>You might find some useful techniques and experiences in <a href="http://biomanta.org/publications/2008/eScience2008.pdf" rel="nofollow">Scalable Semantics – the Silver Lining of Cloud Computing</a> by Andre Newman, Yuan-Fang Li and Jane Hunter. They use MapReduce to populate a distributed RDF molecule store. RDF molecules have a lot of similarities with Symmetric Concise Bounded Descriptions.</p>

http://www.semanticoverflow.com/questions/805/is-the-facebooks-open-graph-the-killer-app-for-the-semantic-web/806#806 Ian Davis 2010-04-23T11:05:13Z 2010-04-23T12:17:16Z

<p>No, I don't think it's the "killer app" but it's still highly significant. Most important is a step towards identifying the thing a page is talking about with a URI. Like rich snippets it's going to result in a very broad sprinkling of tiny amounts of structured data. That is going to have a trickle down effect because people will start seeking out the tools that can produce it thereby prompting the CMS providers to add RDFa as a capability. We'll see web production agencies start to develop this area as a core competency and start to see differentiation based on how they enable the data to be used by as many services as possible. As the data emerges we'll start to see consumption innovation such as browser extensions, smart copy and paste etc. Then the search engines will start picking this up and knitting it together. Hopefully SearchMonkey can already do this - given the Microsoft/Yahoo/Facebook trinity you have to assume they can.</p>

http://www.semanticoverflow.com/questions/744/what-is-a-good-elevator-pitch-for-linked-data Ian Davis 2010-04-16T00:30:05Z 2010-04-22T23:17:24Z

<p>I've seen several attempts at creating elevator pitches for the semantic web in the past, but the community's thinking has advanced a lot in the past few years and the simpler formulation of Linked Data is more readily understandable for most people. So what is the elevator pitch for Linked Data today. I am looking specifically for elevator pitches that focus on the goals and benefits, not the technology.</p> <p><a href="http://en.wikipedia.org/wiki/Elevator_pitch" rel="nofollow">http://en.wikipedia.org/wiki/Elevator_pitch</a></p>

http://www.semanticoverflow.com/questions/757/which-owl-reasoners-understand-named-graphs Ian Davis 2010-04-17T17:13:10Z 2010-04-22T11:25:49Z

<p>Are there any OWL reasoners that can work across named graphs? If so, how do they fit with SPARQL queries that involve only some of the named graphs thereby restricting some of the possibe inferences? Do any reasoners reason with the named graphs themselves, eg what happens if you say two named graph URIs are owl:sameAs one another?</p>

http://www.semanticoverflow.com/questions/723/rdf-storages-vs-other-nosql-storages/756#756 Ian Davis 2010-04-16T20:17:46Z 2010-04-16T20:17:46Z

<p>One difference between NoSQL and RDF stores that I see is that the former don't provide for searching or for joins. RDF stores do both but share the NoSQL benefit of schemaless data.</p>

http://www.semanticoverflow.com/questions/742/why-is-scovo-dataset-a-skos-concept Ian Davis 2010-04-16T00:06:00Z 2010-04-16T08:13:05Z

<p>Today I noticed that scovo:Dataset rdf:type skos:Concept (see <a href="http://sw.joanneum.at/scovo/schema.html#body-Classes).This" rel="nofollow">http://sw.joanneum.at/scovo/schema.html#body-Classes).This</a> doesn't fit with my model of what a dataset is. I think it is a physical set of data, not an abstract conceptualisation. </p> <p>What is the reasoning behind scovo:Dataset being of type skos:Concept?</p>

http://www.semanticoverflow.com/questions/750/how-to-get-started-with-virtuoso-universal-server-for-rdf-querying/751#751 Ian Davis 2010-04-16T07:57:56Z 2010-04-16T07:57:56Z

<p>Openlink provide detailed instructions and tutorial information on their site. A good tutorial starts here: <a href="http://virtuoso.openlinksw.com/dataspace/dav/wiki/Main/VOSTutorial" rel="nofollow">http://virtuoso.openlinksw.com/dataspace/dav/wiki/Main/VOSTutorial</a></p> <p>The main information about Virtuoso, including installation instructions and troubleshooting can be found at <a href="http://virtuoso.openlinksw.com/dataspace/dav/wiki/Main/" rel="nofollow">http://virtuoso.openlinksw.com/dataspace/dav/wiki/Main/</a></p>

http://www.semanticoverflow.com/questions/747/basic-principle-of-onthology/749#749 Ian Davis 2010-04-16T07:39:13Z 2010-04-16T07:39:13Z

<p>I think you are mixing up concepts. You wouldn't create a webpage with an ontology. Ontologies are used to describe some portion of the world. In the Semantic Web ontologies are used to express concepts and relations about real things so that computers can act upon them. For example FOAF (Friend of a Friend) is an ontology that describes some aspects of human relationships and interactions. A computer can read data that has been expressed using the FOAF ontology to compute things like friend networks.</p>

http://www.semanticoverflow.com/questions/623/how-to-merge-properly-data-sources-with-owlsameas/743#743 Ian Davis 2010-04-16T00:20:15Z 2010-04-16T00:20:15Z

<p>Since you say you are doing the consolidation, I'm assuming you are adding the owl:sameAs triples yourself. I would also use the canonicalUri property (http://open.vocab.org/terms/canonicalUri) to specify which URI you would prefer to use. Your data would look like this:</p> <pre><code>&lt;http://source1/companyA&gt; a &lt;http://source1#Company&gt; . &lt;http://source1/companyA&gt; rdfs:label "Company A" . &lt;http://source2/compA&gt; rdfs:label "Comp A" . &lt;http://source1/companyA&gt; owl:sameAs &lt;http://source2/compA&gt; . &lt;http://source1/companyA&gt; ov:canonicalUri "http://source2/compA" . </code></pre> <p>Then your query becomes:</p> <pre><code>select distinct ?uri, ?l where { ?s a &lt;http://source1#Company&gt; ; ov:canonicalUri ?uri . optional(?s rdfs:label ?l) . } </code></pre>

http://www.semanticoverflow.com/questions/501/qa-sites-that-publish-linked-data/741#741 Ian Davis 2010-04-16T00:00:01Z 2010-04-16T00:00:01Z

<p>I don't believe any do, but StackOverflow publishes full dumps of its databases:</p> <p><a href="http://blog.stackoverflow.com/category/cc-wiki-dump/" rel="nofollow">http://blog.stackoverflow.com/category/cc-wiki-dump/</a></p>

http://www.semanticoverflow.com/questions/1229/fips-country-codes-in-rdf Ian Davis 2010-07-09T11:38:04Z 2010-07-09T11:38:04Z

Thanks, I should have added that link too.

http://www.semanticoverflow.com/questions/1175/should-we-seed-this-site-with-faqs/1176#1176 Ian Davis 2010-07-05T14:01:54Z 2010-07-05T14:01:54Z

I was thinking of questions like these: <a href="http://www.thefigtrees.net/lee/sw/sparql-faq" rel="nofollow">thefigtrees.net/lee/sw/sparql-faq</a>

http://www.semanticoverflow.com/questions/505/what-ruby-library-do-you-use-for-working-with-rdf/824#824 Ian Davis 2010-07-05T13:12:12Z 2010-07-05T13:12:12Z

think this answer should be a comment on the earlier answer

http://www.semanticoverflow.com/questions/1092/pointers-to-binary-rdf Ian Davis 2010-06-29T09:28:25Z 2010-06-29T09:28:25Z

It came up in discussions and it had never occured to me that people were trying it, so I wanted more background

http://www.semanticoverflow.com/questions/1095/alternatives-to-owlsameas-for-linked-data/1098#1098 Ian Davis 2010-06-27T14:32:10Z 2010-06-27T14:32:10Z

I think any linking/identity vocabulary would be superproperties of the skos ones

http://www.semanticoverflow.com/questions/1095/alternatives-to-owlsameas-for-linked-data/1096#1096 Ian Davis 2010-06-27T04:58:59Z 2010-06-27T04:58:59Z

that two URIs denote the same thing, or a similar thing, or things that might be the same for some purposes etc.

http://www.semanticoverflow.com/questions/1057/rif-libraries-for-java/1069#1069 Ian Davis 2010-06-25T14:19:04Z 2010-06-25T14:19:04Z

I believe RIF support is coming soon for Jena

http://www.semanticoverflow.com/questions/876/are-symmetric-concise-bounded-description-rdf-molecules-and-minimum-self-contain/878#878 Ian Davis 2010-05-13T19:38:21Z 2010-05-13T19:38:21Z

Dave, in your first example, I don't think t3 would be in the SCBD for the same reason t5 is not.

http://www.semanticoverflow.com/questions/785/schemaweb-status/786#786 Ian Davis 2010-04-19T20:01:58Z 2010-04-19T20:01:58Z

schemapedia.com has a sparql service at <a href="http://api.talis.com/stores/schemapedia/services/sparql" rel="nofollow">api.talis.com/stores/schemapedia/services/sparql</a> (although i intend to wrap that with a schemapedia.com hosted page)

http://www.semanticoverflow.com/questions/744/what-is-a-good-elevator-pitch-for-linked-data/745#745 Ian Davis 2010-04-16T13:24:33Z 2010-04-16T13:24:33Z

yes, fair point. Assume the audience is a business owner.

http://www.semanticoverflow.com/questions/744/what-is-a-good-elevator-pitch-for-linked-data/746#746 Ian Davis 2010-04-16T07:45:19Z 2010-04-16T07:45:19Z

Yes I agree with the sentiment (of course I would!). But it doesn't answer the question of what advantage that gives. They have to figure it out for themselves and if they don't have direct developer experience with databases they won't see the current difficulty. Database vendors have been saying for 4 decades how they will make data management smooth, easy and painless.

http://www.semanticoverflow.com/questions/744/what-is-a-good-elevator-pitch-for-linked-data/745#745 Ian Davis 2010-04-16T07:43:04Z 2010-04-16T07:43:04Z

Yes, I use this analogy too. I sometimes talk about the switch over from asking &quot;why should I have a website?&quot; to &quot;why shouldn't I have a website?&quot; that occurred around 1999. But there are lots of forces that could prevent or delay that switch in thinking for linked data. An elevator pitch to get people hooked on the idea would be very helpful.

http://www.semanticoverflow.com/questions/640/dct-or-dcterms/643#643 Ian Davis 2010-04-15T10:54:41Z 2010-04-15T10:54:41Z

The question is asking about the conventions around the namespace prefix to use, not the property URIs. So while your information is correct, it's not answering the question.

http://www.semanticoverflow.com/questions/716/storing-rdf-data-into-hbase Ian Davis 2010-04-12T22:08:59Z 2010-04-12T22:08:59Z

Storing is easy, isn't the complex part the querying especially joins?

http://www.semanticoverflow.com/questions/464/who-offers-linked-data-training/474#474 Ian Davis 2010-01-12T21:03:51Z 2010-01-12T21:03:51Z

Yes, we do offer general linked data training. Email me at ian.davis@talis.com