The majority of OWL ontologies in the emerging SemanticWeb are constructed from properties that lack domain and range constraints. Constraints in OWL are different from the familiar uses in programming languages and databases. They are actually type assertions that are made about the individualswhich are connected by the property. Because they are type assertions these assertions can add vital information to the individuals involved and give information on how the defining property may be used. Three different automated generation techniques are explored in this research: disjunction, least-common named subsumer, and vivification. Each algorithm is compared for the ability to generalize, and the performance impacts with respect to the reasoner. A large sample of ontologies from the Swoogle repository are used to compare real-world performance of these techniques. Using generated facts is a type of default reasoning. This may conflict with future assertions to the knowledge base. While general default reasoning is non-monotonic and undecidable a novel approach is introduced to support efficient contraction of the default knowledge. Constraint generation and default reasoning, together, enable a robust and efficient generation of domain and range constraints which will result in the inference of additional facts and improved performance for a number of Semantic Web applications.
Conrad Barski, M.D. will give a talk on “How To Tell Stuff To Your Computer — The Enigmatic Art of Knowledge Representation” at UMBC at 1:00pm on Friday 17 October in Lecture Hall 8 in the ITE building.
Barski maintains an interesting site, Lisperati , that has graphical introductions to a number of topics, including Lisp, Haskell, Emacs, etc. and well as serving as he home of FringeDC an informal group of people interested in “fringe” programming languages.
Here’s the abstract for his talk.
“Have you ever wondered how we take information from the “real world” and put it into our computers? When we do this, do we lose parts of the information? Are some concepts just too hard to turn into ones and zeroes? How is our ability to enter information limited by the data structures we use inside of our computers? These questions enter into a science that is rarely discussed: The science of Knowledge Representation.
My presentation on KR will include some navel gazing, but also some nitty-gritty practical examples of Description Logics, RDF, and other modern approaches to capturing complicated information within a computer. We will also discuss some likely future directions this field may head into.”
Dr. Barski is a Medical Software Developer working on cardiology procedure documentation for Wolters Kluwer Health. He is also currently working on a textbook on the Common Lisp programming language.
You can submit a question either before, during or after the talk here.
David Huynh completed his PhD at MIT CSAIL last year and joined MetaWeb a few months ago, where he has been working on new and better interfaces to explore the data encoded in their Freebase system. He recently released Parallax as a prototype browsing interface for Freebase. Here is a video that shows the interface in action.
Freebase is “an open database of the world’s information” that is constructed by a Wiki-like collaborative community. In many ways it is like the Semantic Web model, with two big differences: (1) the data is stored centrally rather than distributed across the Web and (2) the representation system is not based on RDF but rather uses a custom built object-oriented data representation language.
Freebase is a great resource. Much of the data is extracted from Wikipedia, so its content has a large overlap with DBpedia. But it is also relatively easy to upload additional information in various structured forms and many have done so, resulting in an extended coverage.
This is clearly a system in the Web of Data space along with the Linking Open Data effort and having it should offer a way for us all to explore the consequences of some of the underlying design decisions.
“2008-06-20: The Semantic Web Deployment Working Group has published a Candidate Recommendation of RDFa in XHTML: Syntax and Processing. Web documents contain significant amounts of structured data, which is largely unavailable to tools and applications. When publishers can express this data more completely, and when tools can read it, a new world of user functionality becomes available, letting users transfer structured data between applications and web sites, and allowing browsing applications to improve the user experience. RDFa is a specification for attributes to be used with languages such as HTML and XHTML to express structured data. See the group’s RDFa implementation report. The Working Group also updated the companion document RDFa Primer. Learn more about the Semantic Web and the HTML Activity.”
Achieving candidate recommendation status is a significant step toward becoming a W3C recommendation. Congratulation to the working group for all of their efforts in developing RDFa.
“Their innovations transformed this approach from a theoretical technique to a highly effective verification technology that enables computer hardware and software engineers to find errors efficiently in complex system designs. This transformation has resulted in increased assurance that the systems perform as intended by the designers. … Clarke of Carnegie Mellon University, and Emerson of the University of Texas at Austin, working together, and Sifakis, working independently for the Centre National de la Recherche Scientifique at the University of Grenoble in France, developed this fully automated approach that is now the most widely used verification method in the hardware and software industries.” (link)
NYU Professor Ted Sider has made a draft of his new book, Logic for Philosophy, available on the Web. He describes it this way:
“This will be a textbook for a “logic literacy” course. It was designed for beginning graduate students in philosophy, but it is also suitable for advanced undergraduate courses. The goal is to introduce students to the logic they need to know in order to read contemporary philosophy journal articles. It emphasizes breadth rather than depth. For example, it discusses modal logic and counterfactuals, but does not prove the central metalogical results for predicate logic (completeness, undecidability, etc.) It will be published by Oxford University Press.
This looks like a good resource for many AI students who need a good overview of logic and don’t want or need to delve into the proofs. Spotted on LTU.
Google base was announce at Nov 15, 2005. It lets users publishing their information in a Semantic Web way: (i) defining an instance of class; (ii)letting users creating and filling attribute-value pair (value in text though); (iii) letting users add keywords as tag; and (iv) allow bulk upload. I wonder if R. Guha is behind it. It is could be a killer app to web directory services, including classifieds like Craig’s List.
(source: http://www.micropersuasion.com/2005/11/google_to_go_ha.html)
UPDATE: Greg Yardley has evidence from a Microsoft blogger that the software giant is also targeting the online classified market with its new Freemont project.
I’m still hoping some improvement from its beta version:
(1) add the total of items at the front page like below (the number was collected as of today’s snapshot)
(2) can I browse every item without being bound by 1000 items limit?
(3) what if many people have create many item types?
(4) can it recommend well-used attributes?
AAAI-06 will include a special technical track on Artificial Intelligence and the Web. This year’s conference will Celebrate “Fifty Years of Artificial Intellligence” and be held at the Seaport Hotel and World Trade Center in Boston 16-20 July 2006. The deadline for submitting papers is 16 February 2006.
The track is especially interested in receiving papers in two active research areas: (i) using text and language analysis to interpret and understand natural language text found on the web and (ii) developing and exploiting Semantic Web languages and systems that explicitly encode knowledge using languages such as RDF and OWL. Innovative papers in other areas describing research involving both AI and the Web are also encouraged. See the track web site for details.
The First International Workshop on AAMAS Workshops (WORKSAAMAS?) has been proposed* for the Fifth International Joint Conference on Autonomous Agents and Multiagent Systems.
Peter Harsha reports that the Senate Appropriations Committee included language in the Senate version of the FY 06 Defense Appropriations bill that strips $55M from DARPA’s Cognitive Computing program, specifically “Learning, Reasoning, and Integrated Cognitive Systems”. That’s a 50% cut in the program. Peter points out that this runs counter to recent congressional sentiment that the role of computer science, especially university-led fundamental computer science, should be strengthened at DARPA.
policy-based frameworks for the semantic web for security, privacy, trust, information filtering, accountability, etc.
applying semantic web technologies in policy frameworks for application domains such as grid computing, networking, storage systems, pervasive computing and specifying agent communities norms.
In addition to presentations of nine submitted papers, Ora Lassila will give an invited talk on “Applying Semantic Web in Mobile and Ubiquitous Computing: Will Policy-Awareness Help?” and a panel of policy researchers will initiate a discussion of “The 2005 Web Policy Zeitgeist”. The proceedings is available and participants can register at the online.
DMOZ in 2005 is a short note from Phil Craven pronouncing dead the once innovative and exciting idea of a community created web directory.
“It was a fine concept, and it looked promising for a while, but the idea of DMOZ becoming the definitive catalog of the Web is gone. Improvements in the search engines eclipsed its value, and the growth rate of the Web meant that it could never achieve its goal. It began with an excellent concept, and they gave it a good shot, but it didn’t work. The continuing growth rate of the Web ensures that it can never work. It continues as a good directory of a large number of web sites, but that is all. And not many people use directories when the search engines produce such good results, and so quickly.”
One supporting fact is that there are only about 3000 active editors and a backlog of over one million submitted links for them to review.
The note caused me to wonder about what’s in store for today’s popular community created, structured knowledge source — Wikipedia. Are it’s days numbered?
Will we will see the development of a machine generated and maintained collection of articles on different topics? Topics that themselves are identified and selected by the machines, as they are in Google News
The development of such a Googlepedia would certainly qualify as a grad challenge — one that might knowledge representation, semantic web technologies, natural language understanding, natural language generation as well as the ability to form a neutral and objective view in the face of conflicting information.
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