Bioinformatics Commons^™

Algorithms For Adapting Materialised Views In Data Warehouses, Mukesh Mohania, Guozhu Dong

Kno.e.sis Publications

In this paper we consider the problem of materialised view adaptation in data warehouses. Materialised views are important in data warehousing where they are used to speed up query processing on large amounts of data. User requirements change over time, which may change the definitions of views dynamically. For such situations, the question arises whether the materialised views should be recomputed from scratch for every change in the definition or they should be obtained by adapting old materialised views. Changes to a view definition may be expensive, if the view is recomputed from scratch. Therefore, it is worthwhile to examine …

On The Portability Of Behavioral Vhdl-93, Krishnaprasad Thirunarayan, Robert Ewing

Kno.e.sis Publications

Goossens defined a structural operational semantics for a subset of VHDL-87 and proved that the parallelism present in VHDL is benign. We extend this work to include shared variables in VHDL-93 that changes the underlying semantic model. In the presence of shared variables, non-deterministic execution of VHDL-93 processes destroys the unique meaning property. We identify and characterize a class of portable VHDL-93 descriptions for which unique meaning property can be salvaged.

Managing Multiple Information Sources Through Ontologies: Relationship Between Vocabulary Heterogeneity And Loss Of Information, Eduardo Mena, Vipul Kashyap, Arantza Illarramendi, Amit P. Sheth

Kno.e.sis Publications

The ability to deal with a huge number of independent and heterogeneous repositories is the most critical problem in Global Information Systems. One approach to enable efficient query processing is by utilizing semantic descriptions (organized as ontologies) of such repositories whenever available.

In this context semantic relationships among ontologies can be used Query Processors. Three kind of relationships are considered: synonyms and hypernyms. Using synonyms the semantic of the query is preserved; however, when synonyms are not available and hypernyms or hyponyms are used there exists some loss of information that must be measured.

1: "To Know Ourselves", The U.S. Department Of Energy, The Human Genome Project

Genomics: Past & Future

AT THE END OF THE ROAD in Little Cottonwood Canyon, near Salt Lake City, Alta is a place of near-mythic renown among skiers. In time it may well assume similar status among molecular geneticists. In December 1984, a conference there, co-sponsored by the U.S. Department of Energy, pondered a single question: Does modern DNA research offer a way of detecting tiny genetic mutations—and, in particular, of observing any increase in the mutation rate among the survivors of the Hiroshima and Nagasaki bombings and their descendants? In short the answer was, Not yet. But in an atmosphere of rare intellectual fertility, …

Observer: An Approach For Query Processing In Global Information Systems Based On Interoperation Across Pre-Existing Ontologies, Eduardo Mena, Vipul Kashyap, Amit P. Sheth, Arantza Illarramendi

Kno.e.sis Publications

The huge number of autonomous and heterogeneous data repositories accessible on the “global information infrastructure” makes it impossible for users to be aware of the locations structure/organization, query languages and semantics of the data in various repositories. There is a critical need to complement current browsing, navigational and information retrieval techniques with a strategy that focuses on information content and semantics. In any strategy that focuses on information content, the most critical problem is that of different vocabularies used to describe similar information across domains. We discuss a scalable approach for vocabulary sharing. The objects in the repositories are represented …

Proof Strategies For Hardware Verification, Robert Eastham, Krishnaprasad Thirunarayan

Kno.e.sis Publications

Ascertaining correctness of digital hardware designs through simulation does not scale-up for large designs because of the sheer combinatorics of the problem. Formal verification of hardware designs holds promise because its computational complexity is of the order of number of different types of components (and not number of components in the design). This approach requires the specification of the behavior and the design in a formal language, and reason with them using a theorem prover. In this paper we attempt to develop a methodology for writing and using these specifications for some important classes of hardware circuits. We examine digital …

Ultrasound Three- Dimensional Velocity Measurements By Feature Tracking, Gregory R. Bashford, Olaf T. Von Ramm

Biomedical Imaging and Biosignal Analysis Laboratory

This article describes a new angle-independent method suitable for three-dimensional (3-D) blood flow velocity measurement that tracks features of the ultrasonic speckle produced by a pulse echo system. In this method, a feature is identified and followed over time to detect motion. Other blood flow velocity measurement methods typically estimate velocity using one- (1-D) or two-dimensional (2-D) spatial and time information. Speckle decorrelation due to motion in the elevation dimension may hinder this estimate of the true 3-D blood flow velocity vector. Feature tracking is a 3-D method with the ability to measure the true blood velocity vector rather than …

Chaos And Detection, Andrew M. Fraser

Systems Science Faculty Publications and Presentations

I report on numerical experiments in which a detector reliably found chaotic signals at signal to noise ratios as low as -15 dB. The detector was based on a variant of the hidden Markov models used in speech research. The task was particularly difficult because the Fourier power spectrum of the noise was constructed to match the spectrum of the signal. I review likelihood ratio detectors, limitations on the performance of linear models implied by the broad Fourier power spectra of chaotic signals, and the upper limit that the Kolmogorov-Sinai (KS) entropy of a chaotic system places on the expected …

Spieltheorie, Alexander Chocholaty, Pascal Hitzler

Computer Science and Engineering Faculty Publications

No abstract provided.

Semantic And Schematic Similarities Between Database Objects: A Context-Based Approach, Vipul Kashyap, Amit P. Sheth

Kno.e.sis Publications

In a multidatabase system, schematic conflicts between two objects are usually of interest only when the objects have some semantic similarity. We use the concept of semantic proximity, which is essentially an abstraction/mapping between the domains of the two objects associated with the context of comparison. An explicit though partial context representation is proposed and the specificity relationship between contexts is defined. The contexts are organized as a meet semi-lattice and associated operations like the greatest lower bound are defined. The context of comparison and the type of abstractions used to relate the two objects form the basis of a …