7346462
Ontology-based extraction and structuring of information from data-rich unstructured documents
We present a new approach to extracting information from unstructured documents based on an application ontology that describes a domain of interest. Starting with such an ontology, we formulate rules to extract constants and context keywords from unstructured documents. For each unstructured document of interest, we extract its constants and keywords and apply a recognizer to organize extracted constants as attribute values of tuples in a generated database schema. To make our approach general, we fix all the processes and change only the ontological description for a different application domain. In experiments we conducted on two different types of unstructured documents taken from the Web, our approach attained recall ratios in the 80% and 90% range and precision ratios near 98%.
3217704
Conceptual-Model-Based Data Extraction from Multiple-Record Web Pages
Abstract Electronically available data on the Web is exploding at an ever increasing pace. Much of this data is unstructured, which makes searching hard and traditional database querying impossible. Many Web documents, however, contain an abundance of recognizable constants that together describe the essence of a document's content. For these kinds of data-rich, multiple-record documents (e.g., advertisements, movie reviews, weather reports, travel information, sports summaries, financial statements, obituaries, and many others) we can apply a conceptual-modeling approach to extract and structure data automatically. The approach is based on an ontology – a conceptual model instance – that describes the data of interest, including relationships, lexical appearance, and context keywords. By parsing the ontology, we can automatically produce a database scheme and recognizers for constants and keywords, and then invoke routines to recognize and extract data from unstructured documents and structure it according to the generated database scheme. Experiments show that it is possible to achieve good recall and precision ratios for documents that are rich in recognizable constants and narrow in ontological breadth. Our approach is less labor-intensive than other approaches that manually or semiautomatically generate wrappers, and it is generally insensitive to changes in Web-page format.
42162123
A Conceptual Clustering Program for Rule Generation
We present an Interesting Situation Generator (ISG) that assists in the synthesis of interpretation rules from basic domain knowledge. The ISG is a hierarchical clustering program that discovers equivalence classes of situations (e.g. types of geological formations) that give rise to qualitatively distinct manifestations (e.g. different patterns of geophysical measurements corresponding to types of geological formations). The equivalence classes can be used by a rule generator to construct an initial set of interpretation rules of the form manifestation ⇒ situation.
9913634
Generalized and stationary scrolling
We present a generalized definition of scrolling that unifies a wide range of existing interaction techniques, from conventional scrolling through pan and zoom systems and fish-eye views. Furthermore it suggests a useful class of new scrolling techniques in which objects do not move across the display. These “stationary scrolling” techniques do not exhibit either of two problems that plague spatial scrolling system: discontinuity in salience and the undermining of the user's spatial memory.
45789414
A Simple and Unifying Approach to Subjective Objects
Abstract Most object-oriented languages are objective: an object always responds to the same message in the same way. Subjective objects more closely match naturally occurring systems, and they provide consistent solutions to a wide range of problems, problems that otherwise must be solved by varied and specialized mechanisms. Applying a perspective-receiver symmetry principle in designing the subjectivity semantics of an object-oriented language results in a semantically uncluttered language with a surprisingly wide range of utility. We employ this approach in creating the language Us, a subjective version of Self.
17086760
Cost profile of a highly assured, secure operating system
The Logical Coprocessing Kernel (LOCK) began as a research project to stretch the state of the art in secure computing by trying to meet or even exceed the “A1” requirements of the Trusted Computer System Evaluation Criteria (TCSEC). Over the span os seven years, the project was transformed into an effort to develop and deploy a product: the Standard Mail Guard (SMG). Since the project took place under a US government contract, the development team needed to maintain detailed records of the time spent on the project. The records from 1987 to 1992 have been combined with information about software code size and error detection. This information has been used to examine the practical impacts of high assurance techniques on a large-scale software development program. Tasks are associated with the A1 formal assurance requirements added approximately 58% to the development cost of security-critical software. In exchange for these costs, the formal assurance tasks (formal specifications, proofs, and specification code correspondence) uncovered 68% of the security flaws detected in LOCK's critical security mechanisms. However, a study of flaw detection during the SMG program found that only 14% of all flaws detected were of the type that could be detected using formal assurance, and that the work of the formal assusrance team only accounted for 19% of all flaws detected. While formal assurance is clearly effective at detecting flaws, its practicality hinges on the degree to which the formally modeled system properties represent all of a system's esential properties.
18629340
Report on the 1984 Distributed Artificial Intelligence Workshop
The fifth Distributed Artificial Intclligencc Workshop tias held at the Schlumberger-Doll Research Laboratory from October 14 to 17, 1984 It was attended by 20 participants from academic and industrial institutions. As in the past,’ this workshop was designed as an informal meeting It included brief research rcport,s from individual groups along with genera1 discussion of questions of common interest. This report summarizes the general discussion and contains summaries of group presentations that have been contributed by individual speakers to scale the resources applied to a problem). Others arc motivated by problem characteristics, such as natural spatial or functional distribution. Finally, some researchers are motivated by the observation that some issues in problcm solving and reasoning (e.g., communication and coherent cooperation) are brought into sharp focus in the distributed setting. The main body of this report contains summaries written by individual attcndces of the workshop. This is, in turn, followed by a brief smnmary of the gcncral discus