Archive for the ‘Semantic Graph’ Category

Context Aware Searching

Thursday, September 19th, 2013

Scaling Up Personalized Query Results for Next Generation of Search Engines

From the post:

North Carolina State University researchers have developed a way for search engines to provide users with more accurate, personalized search results. The challenge in the past has been how to scale this approach up so that it doesn’t consume massive computer resources. Now the researchers have devised a technique for implementing personalized searches that is more than 100 times more efficient than previous approaches.

At issue is how search engines handle complex or confusing queries. For example, if a user is searching for faculty members who do research on financial informatics, that user wants a list of relevant webpages from faculty, not the pages of graduate students mentioning faculty or news stories that use those terms. That’s a complex search.

“Similarly, when searches are ambiguous with multiple possible interpretations, traditional search engines use impersonal techniques. For example, if a user searches for the term ‘jaguar speed,’ the user could be looking for information on the Jaguar supercomputer, the jungle cat or the car,” says Dr. Kemafor Anyanwu, an assistant professor of computer science at NC State and senior author of a paper on the research. “At any given time, the same person may want information on any of those things, so profiling the user isn’t necessarily very helpful.”

Anyanwu’s team has come up with a way to address the personalized search problem by looking at a user’s “ambient query context,” meaning they look at a user’s most recent searches to help interpret the current search. Specifically, they look beyond the words used in a search to associated concepts to determine the context of a search. So, if a user’s previous search contained the word “conservation” it would be associated with concepts likes “animals” or “wildlife” and even “zoos.” Then, a subsequent search for “jaguar speed” would push results about the jungle cat higher up in the results — and not the automobile or supercomputer. And the more recently a concept has been associated with a search, the more weight it is given when ranking results of a new search.

I rather like the contrast of ambiguous searches being resolved with “impersonal techniques.”

The paper, Scaling Concurrency of Personalized Semantic Search over Large RDF Data by Haizhou Fu, Hyeongsik Kim, and Kemafor Anyanwu, has this abstract:

Recent keyword search techniques on Semantic Web are moving away from shallow, information retrieval-style approaches that merely find “keyword matches” towards more interpretive approaches that attempt to induce structure from keyword queries. The process of query interpretation is usually guided by structures in data, and schema and is often supported by a graph exploration procedure. However, graph exploration-based interpretive techniques are impractical for multi-tenant scenarios for large database because separate expensive graph exploration states need to be maintained for different user queries. This leads to significant memory overhead in situations of large numbers of concurrent requests. This limitation could negatively impact the possibility of achieving the ultimate goal of personalizing search. In this paper, we propose a lightweight interpretation approach that employs indexing to improve throughput and concurrency with much less memory overhead. It is also more amenable to distributed or partitioned execution. The approach is implemented in a system called “SKI” and an experimental evaluation of SKI’s performance on the DBPedia and Billion Triple Challenge datasets show orders-of-magnitude performance improvement over existing techniques.

If you are interesting in scaling issues for topic maps, note the use of indexing as opposed to graph exploration techniques in this paper.

Also consider mining “discovered” contexts that lead to “better” results from the viewpoint of users. Those could be the seeds for serializing those contexts as topic maps.

Perhaps even directly applicable to work by researchers, librarians, intelligence analysts.

Seasoned searchers use richer contexts in searching that the average user and if those contexts are captured, they could enrich the search contexts of the average user.

Semantic Search Over The Web (SSW 2013)

Monday, March 18th, 2013

3RD International Workshop onSemantic Search Over The Web (SSW 2013)

Dates:

Abstract Papers submission: May 31, 2013 – 15:00 (3:00 pm) EDT
(Short) Full Paper submission: June 7, 2013 – 15:00 (3:00 pm) EDT
Author notification: July 19, 2013
Camera-ready copy due: August 2, 2013
Workshop date: During VLDB (Aug 26 – Aug 30)

From the webpage:

We are witnessing a smooth evolution of the Web from a worldwide information space of linked documents to a global knowledge base, composed of semantically interconnected resources. To date, the correlated and semantically annotated data available on the web amounts to 25 billion RDF triples, interlinked by around 395 million RDF links. The continuous publishing and the integration of the plethora of semantic datasets from companies, government and public sector projects is leading to the creation of the so-called Web of Knowledge. Each semantic dataset contributes to extend the global knowledge and increases its reasoning capabilities. As a matter of facts, researchers are now looking with growing interest to semantic issues in this huge amount of correlated data available on the Web. Many progresses have been made in the field of semantic technologies, from formal models to repositories and reasoning engines. While the focus of many practitioners is on exploiting such semantic information to contribute to IR problems from a document centric point of view, we believe that such a vast, and constantly growing, amount of semantic data raises data management issues that must be faced in a dynamic, highly distributed and heterogeneous environment such as the Web.

The third edition of the International Workshop on Semantic Search over the Web (SSW) will discuss about data management issues related to the search over the web and the relationships with semantic web technologies, proposing new models, languages and applications.

The research issues can be summarized by the following problems:

  • How can we model and efficiently access large amounts of semantic web data?
  • How can we effectively retrieve information exploiting semantic web technologies?
  • How can we employ semantic search in real world scenarios?

The SSW Workshop invites researchers, engineers, service developers to present their research and works in the field of data management for semantic search. Papers may deal with methods, models, case studies, practical experiences and technologies.

Apologies for the uncertainty of the workshop date. (There is confusion about the date on the workshop site, one place says the 26th, the other the 30th. Check before you make reservation/travel arrangements.)

I differ with the organizers on some issues but on the presence of: “…data management issues that must be faced in a dynamic, highly distributed and heterogeneous environment such as the Web,” there is no disagreement.

That’s the trick isn’t it? In any confined or small group setting, just about any consistent semantic solution will work.

The hurly-burly of a constant stream of half-heard, partially understood communications across distributed and heterogeneous systems tests the true mettle of semantic solutions.

Not a quest for perfect communication but “good enough.”

Entity disambiguation using semantic networks

Sunday, September 2nd, 2012

Entity disambiguation using semantic networks by Jorge H. Román, Kevin J. Hulin, Linn M. Collins and James E. Powell. Journal of the American Society for Information Science and Technology, published 29 August 2012.

Abstract:

A major stumbling block preventing machines from understanding text is the problem of entity disambiguation. While humans find it easy to determine that a person named in one story is the same person referenced in a second story, machines rely heavily on crude heuristics such as string matching and stemming to make guesses as to whether nouns are coreferent. A key advantage that humans have over machines is the ability to mentally make connections between ideas and, based on these connections, reason how likely two entities are to be the same. Mirroring this natural thought process, we have created a prototype framework for disambiguating entities that is based on connectedness. In this article, we demonstrate it in the practical application of disambiguating authors across a large set of bibliographic records. By representing knowledge from the records as edges in a graph between a subject and an object, we believe that the problem of disambiguating entities reduces to the problem of discovering the most strongly connected nodes in a graph. The knowledge from the records comes in many different forms, such as names of people, date of publication, and themes extracted from the text of the abstract. These different types of knowledge are fused to create the graph required for disambiguation. Furthermore, the resulting graph and framework can be used for more complex operations.

To give you a sense of the author’s approach:

A semantic network is the underlying information representation chosen for the approach. The framework uses several algorithms to generate subgraphs in various dimensions. For example: a person’s name is mapped into a phonetic dimension, the abstract is mapped into a conceptual dimension, and the rest are mapped into other dimensions. To map a name into its phonetic representation, an algorithm translates the name of a person into a sequence of phonemes. Therefore, two names that are written differently but pronounced the same are considered to be the same in this dimension. The “same” qualification in one of these dimensions is then used to identify potential coreferent entities. Similarly, an algorithm for generating potential alternate spellings of a name has been used to find entities for comparison with similarly spelled names by computing word distance.

The hypothesis underlying our approach is that coreferent entities are strongly connected on a well-constructed graph.

Question: What if the nodes to which the coreferent entities are strongly connected are themselves ambiguous?

Creating a Semantic Graph from Wikipedia

Sunday, June 3rd, 2012

Creating a Semantic Graph from Wikipedia by Ryan Tanner, Trinity University.

Abstract:

With the continued need to organize and automate the use of data, solutions are needed to transform unstructred text into structred information. By treating dependency grammar functions as programming language functions, this process produces \property maps” which connect entities (people, places, events) with snippets of information. These maps are used to construct a semantic graph. By inputting Wikipedia, a large graph of information is produced representing a section of history. The resulting graph allows a user to quickly browse a topic and view the interconnections between entities across history.

Of particular interest is Ryan’s approach to the problem:

Most approaches to this problem rely on extracting as much information as possible from a given input. My approach comes at the problem from the opposite direction and tries to extract a little bit of information very quickly but over an extremely large input set. My hypothesis is that by doing so a large collection of texts can be quickly processed while still yielding useful output.

A refreshing change from semantic orthodoxy that has a happy result.

Printing the thesis now for a close read.

(Source: Jack Park)