2018 IEEE International Conference on Big Data (Big Data), 2018
With the increasing prevalence of location sensor devices like GPS, it has been possible to colle... more With the increasing prevalence of location sensor devices like GPS, it has been possible to collect large datasets of a special type of spatio-temporal data called trajectory data. A trajectory is a discrete sequence of positions that a moving object occupies in space as time passes. Such large datasets enable researchers to study the behavior of the objects describing these movements by issuing spatial queries. Among the queries that can be issued are top-K trajectory similarity queries, which retrieve the K most similar trajectories to a given query trajectory. This query has applications in many areas, such as urban planning, ecology and social networking; however, this query is computationally expensive. In this work, we introduce a new parallel top-K trajectory similarity query technique for GPUs, FastTopK, to deal with these challenges. Our experiments on two large real-life datasets showed that FastTopK produces on average 107.96X smaller candidate result sets, and 3.36X faster query execution times than the existing state-of-the-art technique, TKSimGPU.
Information Security, Privacy and Confidentiality National Science Foundation's Past and Current Funding Profile and Future Opportunities
2006 International Conference on Collaborative Computing: Networking, Applications and Worksharing, 2006
Summary form only given. National Science Foundation (NSF) has a long-standing interest in protec... more Summary form only given. National Science Foundation (NSF) has a long-standing interest in protecting, enhancing and evaluating information security, privacy and confidentiality in information systems. The interest is broad including new architectures, algorithms, data collection and evaluation methods. All these are in recognition of newly emerging environments and applications (e.g. pervasive computing, mobile, sensor and distributed databases, discovery and handling
2017 IEEE International Conference on Big Data (Big Data), 2017
Traditional data mining algorithms are exceptional at seeing patterns in data that humans cannot,... more Traditional data mining algorithms are exceptional at seeing patterns in data that humans cannot, but are often confused by details that are obvious to the organic eye. Algorithms that include humans "in-the-loop" have proved beneficial for accuracy by allowing a user to provide direction in these situations, but the slowness of human interactions causes execution times to increase exponentially. Thus, we seek to formalize frameworks that include humans "over-the-loop", giving the user an option to intervene when they deem it necessary while not having user feedback be an execution requirement. With this strategy, we hope to increase the accuracy of solutions with minimal losses in execution time. This paper describes our vision of this strategy and associated problems.
INDUSTRY PERSPECTIVES (A. Eisenberg and J. Melton, editors)
Query Reformulation with Constraints................................................................ more Query Reformulation with Constraints......................................................................................... 65 A. Deutsch, L.Popa and V. Tannen [Editor’s note: With the exception of the last pages –which would be the back cover of the printed issue – that are not
This thesis describes the effects of operational parameters upon aeroengine flutter stability. Th... more This thesis describes the effects of operational parameters upon aeroengine flutter stability. The study is composed of three parts: theoretical development of relevant parameters, exploration of a computational model, and analysis of fully scaled test data. Results from these studies are used to develop a rational flutter clearance methodology-a test procedure to ensure flutter-free operation. It is shown, under conditions relevant to aeroengines, that four nondimensional parameters are necessary and sufficient for flutter stability assessment of a given rotor geometry. We introduce a new parameter, termed the reduced damping, g/p *, which collapses the combined effects of mechanical damping and mass ratio (blade mass to fluid inertia). Furthermore, the introduction of the compressible reduced frequency, K*, makes it possible to uniquely separate the corrected performance map from the non-dimensional operating environment (including inlet temperature and pressure). Simultaneous plo...
Reduction of nitrogen and phosphorus inputs into surface waters from nonpoint agricultural source... more Reduction of nitrogen and phosphorus inputs into surface waters from nonpoint agricultural sources requires targeted application of differentiated measures. In the study focused on soil and water conservation in the Jihlava river basin upstream of the Dalešice reservoir, we identified areas at potential risk of soil erosion, elevated infiltration and nutrient leaching, tile-drained areas and vulnerable riparian zones of water bodies. We then designed a system of complex protective measures for this river basin in more variants, and their effectiveness was estimated using simple empirical model calculations and research findings. Application of the measures defined by optimal variant 3 in the studied watershed could lead to reduction of the soil erosion effects on the surface water quality by 26.5%, with simultaneous reduction of the amount of washed out total nitrogen by 22.8%. The results of our study constitute a partial component of the Qualitative Model of the Jihlava River Basin and they were provided for use to the Vysočina Region authorities and the State Land Office.
Dose-related vestibular and cochlear effects of transtympanic gentamicin
The American journal of otology, 1998
To test the relative dose-related cochlear and vestibular ototoxicity produced by transtympanical... more To test the relative dose-related cochlear and vestibular ototoxicity produced by transtympanically injected gentamicin in the Mongolian gerbil. Transtympanic gentamicin is gaining favor as a relatively noninvasive treatment for Meniere's disease (MD). Few basic science studies exist regarding the vestibular and cochlear toxicities and dosage and administration schedules, however. The absence of standardized procedures and use of different species as animal models may account for the variable outcomes and lack of agreement found in the literature. Histologic evaluation was performed on inner ears from Mongolian gerbils to study vestibular and cochlear damage. Comparisons were made between animals receiving single (1x) and five (5x) daily injections of gentamicin/gelfoam slurry and similarly injected (saline/gelfoam) and noninjected controls. Two weeks after injection, qualitative and quantitative changes were seen in posterior cristae hair cells in the 1x and 5x gentamicin injec...
The general nomadic computing model has two distinct sets of entities: a fixed network system and... more The general nomadic computing model has two distinct sets of entities: a fixed network system and a continu-ously changing set of mobile hosts (Fig. 1). The fixed networking system has a collection of static computers connected by a wired network. Some static units are able to ...
Proceedings 1999 International Symposium on Database Applications in Non-Traditional Environments (DANTE'99) (Cat. No.PR00496)
Many current multimedia database management systems perform content-based retrieval of images by ... more Many current multimedia database management systems perform content-based retrieval of images by extracting the values of various features from every object stored in their system. This can be time-consuming, especially if extracting the features requires a human to analyze each object. This process can be minimized in multimedia database systems that store images as a sequence of editing operations, called specifications, instead of the usual binary format. This paper discusses the advantages and applicability of such systems and the issues that must be resolved in order to develop them.
Securing MANET databases using metadata and context information
MILCOM 2008 - 2008 IEEE Military Communications Conference, 2008
Existing commercial database security products cannot guarantee to provide the same level databas... more Existing commercial database security products cannot guarantee to provide the same level database security in Mobile Ad-Hoc Networks (MANET) as in wired networks. In this paper, we presented a secure MANET database system that uses metadata and context information for database access control. First, we designed and implemented a context-based security model that uses context factors, such as location and
Workshop on Advances in Geographic Information Systems, 2002
Broadcasting is an effective and efficient way to disseminate public geographical information to ... more Broadcasting is an effective and efficient way to disseminate public geographical information to massive users. In this paper, we use R-tree to index broadcast geographical data. Based on our observation that geographical data and their accesses are often concentrated (clustered) in real applications, we propose a novel prioritized sequencing method by considering access frequencies based on application semantics to reduce
Using an Ontology to Improve Search in a Terrorism Database System
In this paper, we present our implementation of a Terrorism Database System and show how to lever... more In this paper, we present our implementation of a Terrorism Database System and show how to leverage the expressive power of an ontology to improve search and document retrieval by extending the knowledge base of Oracle Text. We begin with a brief introduction to our Terrorism Database System, now in production. Then we describe the structure of the ontology, the interface for knowledge workers to add/edit/delete the content of the ontology, and the techniques for semi-automatic term generation as well as semantic content resolution when classifying documents.
XSLT and XQuery are the languages developed by the W3C for transforming and querying XML data. XS... more XSLT and XQuery are the languages developed by the W3C for transforming and querying XML data. XSLT and XQuery have the same expressive power and can be indeed translated into each other. Many tools either support XSLT or XQuery. In this paper, we show how to translate XSLT stylesheets into equivalent XQuery expressions and vice versa, so that we can apply the same tools to both languages. We also present a performance analysis that compares the execution times of the translation of the original query and of its translated expression using various current XSLT processors and XQuery evaluators.
Knowledge discovery from gene expression databases has become an important research area for biol... more Knowledge discovery from gene expression databases has become an important research area for biologists since the growing number of gene sequences was obtained. This paper studies the transcription factor(s) required for expression of the target genes using data mining association rule techniques. To apply the association rules to mine the transcription factors essential to certain gene expressions, we defined each type of tissues as a set of transactions or a dataset. Each dataset consists of transcription factors and the target genes. The Apriori mining algorithm was prototyped and the gene sequence data were tested. The results were obtained by pruning the itemsets before and after applying the Apriori algorithm, in which the false results were eliminated. The data items (transcription factors) obtained from this program were compared with those data obtained through experimental research. The comparison results indicated that it may be effective to apply data mining association rules to obtain transcription factors associated with gene expressions.
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Papers by L. Gruenwald