52,009 research outputs found
Machine Learning of User Profiles: Representational Issues
As more information becomes available electronically, tools for finding
information of interest to users becomes increasingly important. The goal of
the research described here is to build a system for generating comprehensible
user profiles that accurately capture user interest with minimum user
interaction. The research described here focuses on the importance of a
suitable generalization hierarchy and representation for learning profiles
which are predictively accurate and comprehensible. In our experiments we
evaluated both traditional features based on weighted term vectors as well as
subject features corresponding to categories which could be drawn from a
thesaurus. Our experiments, conducted in the context of a content-based
profiling system for on-line newspapers on the World Wide Web (the IDD News
Browser), demonstrate the importance of a generalization hierarchy and the
promise of combining natural language processing techniques with machine
learning (ML) to address an information retrieval (IR) problem.Comment: 6 page
CHORUS Deliverable 2.2: Second report - identification of multi-disciplinary key issues for gap analysis toward EU multimedia search engines roadmap
After addressing the state-of-the-art during the first year of Chorus and establishing the existing landscape in
multimedia search engines, we have identified and analyzed gaps within European research effort during our second year.
In this period we focused on three directions, notably technological issues, user-centred issues and use-cases and socio-
economic and legal aspects. These were assessed by two central studies: firstly, a concerted vision of functional breakdown
of generic multimedia search engine, and secondly, a representative use-cases descriptions with the related discussion on
requirement for technological challenges. Both studies have been carried out in cooperation and consultation with the
community at large through EC concertation meetings (multimedia search engines cluster), several meetings with our
Think-Tank, presentations in international conferences, and surveys addressed to EU projects coordinators as well as
National initiatives coordinators. Based on the obtained feedback we identified two types of gaps, namely core
technological gaps that involve research challenges, and âenablersâ, which are not necessarily technical research
challenges, but have impact on innovation progress. New socio-economic trends are presented as well as emerging legal
challenges
Knowledge Representation and WordNets
Knowledge itself is a representation of âreal factsâ.
Knowledge is a logical model that presents facts from âthe real worldâ witch can be expressed in a formal language. Representation means the construction of a model of some part of reality.
Knowledge representation is contingent to both cognitive science and artificial intelligence. In cognitive science it expresses the way people store and process the information. In the AI field the goal is to store knowledge in such way that permits intelligent programs to represent information as nearly as possible to human intelligence.
Knowledge Representation is referred to the formal representation of knowledge intended to be processed and stored by computers and to draw conclusions from this knowledge.
Examples of applications are expert systems, machine translation systems, computer-aided maintenance systems and information retrieval systems (including database front-ends).knowledge, representation, ai models, databases, cams
Information Retrieval Models
Many applications that handle information on the internet would be completely\ud
inadequate without the support of information retrieval technology. How would\ud
we find information on the world wide web if there were no web search engines?\ud
How would we manage our email without spam filtering? Much of the development\ud
of information retrieval technology, such as web search engines and spam\ud
filters, requires a combination of experimentation and theory. Experimentation\ud
and rigorous empirical testing are needed to keep up with increasing volumes of\ud
web pages and emails. Furthermore, experimentation and constant adaptation\ud
of technology is needed in practice to counteract the effects of people that deliberately\ud
try to manipulate the technology, such as email spammers. However,\ud
if experimentation is not guided by theory, engineering becomes trial and error.\ud
New problems and challenges for information retrieval come up constantly.\ud
They cannot possibly be solved by trial and error alone. So, what is the theory\ud
of information retrieval?\ud
There is not one convincing answer to this question. There are many theories,\ud
here called formal models, and each model is helpful for the development of\ud
some information retrieval tools, but not so helpful for the development others.\ud
In order to understand information retrieval, it is essential to learn about these\ud
retrieval models. In this chapter, some of the most important retrieval models\ud
are gathered and explained in a tutorial style
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