1,860 research outputs found

    Region-based indexing in an image database

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    Image retrieval systems based on the image-query-by-example paradigm locate their answer set using a similarity measure of the query image with all images stored in the database. Although this approach generally works for quick re-location of `identical' or partly occluded images, it does not support the more interesting query type aimed at finding images with a particular image fragment. In this paper we introduce a regionbased indexing scheme to support retrieval of images on the basis of both global and local image features

    Navigating through a forest of quad trees to spot images in a database

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    This paper describes how we maintain color and spatial index information on more than 1,000,000 images and how we allow users to browse the spatial color feature space. We break down all our images in color-based quad trees and we store all quad trees in our main-memory database. We allow users to browse the quad trees directly, or they can pre-select images through our color bit vector, which acts as an index accelerator. A Java based textsc{gui is used to navigate through our image indexes

    The effect of SU-8 patterned surfaces on the response of the quartz crystal microbalance

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    In this work we present data showing the effect of patterning layers of SU-8 photoresist on a quartz crystal microbalance (QCM) and subsequent chemical treatment to increase their hydrophobicity. Patterns with 5 mu m diameter pillars spaced every 10 mu m have been fabricated with heights of 3, 5 and 10 mu m in addition to equivalent thickness flat layers. Contact angle measurements have been made before and after the hydrophobic chemical treatment. The change in resonant frequency of the QCM has been investigated as the surfaces were submerged in solutions of water/PEG with changing viscosity-density product

    The Neoproterozoic Rivieradal Group of Kronprins Christian Land, eastern North Greenland

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    The Rivieradal Group, formally defined here, is confined to the Vandredalen thrust sheet of the Caledonian orogen in Kronprins Christian Land, eastern North Greenland. It comprises a succession of Neoproterozoic siliciclastic sediments that represent the fill of a half-graben basin. The syn-rift Rivieradal Group is overlain by post-rift sediments of the Hagen Fjord Group. The latter succession is present in both the thrust sheet and the Caledonian foreland to the west. In the foreland, where the Rivieradal Group is not represented, the Hagen Fjord Group disconformably overlies Palaeoproterozoic–Mesoproterozoic sandstones of the Independence Fjord Group

    Congruence and scope for incorporating ACTIVE principles into project management competency frameworks

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    Project Management competency has been recognised as a critical source of competitive advantage and key to successful project delivery. For this reason it is important that the competency frameworks used to achieve competence in project organizations are effective and fit for purpose. The European Construction Institute (ECI) developed eight principles through the ACTIVE (Achieving Competitiveness Through Innovation and Value Enhancement) initiative in an attempt to add value to the delivery of projects. This research explored the congruence and scope for incorporating the ACTIVE principles into current competency frameworks in use by project organizations. An interpretive and qualitative research approach was adopted, using semi-structured interviews with eight Project Managers and Learning and Development Managers in project organizations. The use of competency frameworks is not as widespread as first thought. Current competency frameworks in use in project organizations are based on a fairly comprehensive body of knowledge and largely congruent with the ACTIVE principles centered around concept definition, team management, supply chain relationship management, communication, risk management, innovation, project execution and performance measurement. However, ACTIVE principles’ underpinning ethos of creating a collaborative working environment in projects is a missing piece worthy of incorporation into competency frameworks currently in use in project organizations

    Self-organizing strategies for a column-store database

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    Column-store database systems open new vistas for improved maintenance through self-organization. Individual columns are the focal point, which simplify balancing conflicting requirements. This work presents two workload-driven self-organizing techniques in a column-store, i.e. adaptive segmentation and adaptive replication. Adaptive segmentation splits a column into non-overlapping segments based on the actual query load. Likewise, adaptive replication creates segment replicas. The strategies can support different application requirements by trading off the reorganization overhead for storage cost. Both techniques can significantly improve system performance as demonstrated in an evaluation of different scenarios

    Fixing the conformal window in QCD

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    A physical characterization of Landau singularities is emphasized, which should trace the lower boundary N_f^* of the conformal window in QCD and supersymmetric QCD. A natural way to disentangle ``perturbative'' from ``non-perturbative'' contributions to amplitudes below N_f^* is suggested. Assuming an infrared fixed point persists in the perturbative part of the QCD coupling even below N_f^* leads to the condition \gamma(N_f^*)=1, where \gamma is the critical exponent. Using the Banks-Zaks expansion, one gets 4<N_f^*<6. This result is incompatible with the existence of an analogue of Seiberg duality in QCD. The presence of a negative ultraviolet fixed point is required both in QCD and in supersymmetric QCD to preserve causality within the conformal window. Evidence for the existence of such a fixed point in QCD is provided.Comment: 10 pages, 1 figure, extended version of a talk given at the QCDNET2000 meeting, Paris, September 11-14 2000; main new material added is evidence for negative ultraviolet fixed point in QC

    The Carnian/Norian boundary succession at Berlin-Ichthyosaur State Park (Upper Triassic, central Nevada, USA)

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    The Upper Carnian-Lower Norian (Upper Triassic) Luning Formation at Berlin-Ichthyosaur State Park (BISP) in central NV (USA) has been sampled using for the first time the bed-by-bed approach for ammonoids, pelagic bivalves, and conodonts, more than 60 years after its first description by Silberling (U.S. Geological Survey Professional Paper 322: 1\u201363, 1959). BISP is historically important for the definition of the uppermost Carnian of the North American Triassic chronostratigraphic scale and is known worldwide as one of the most important ichthyosaur Fossil-Lagerst\ue4tte because of its extraordinary record of 37 articulated, large-sized specimens of Shonisaurus popularis. Nearly 190 ammonoids were collected from two stratigraphic sections, documenting all the latest Carnian to Early Norian ammonoid faunas previously described by Silberling. Halobiids were collected from five levels, and the first report of conodonts from BISP includes faunas from 13 levels. The ~340-m thick Brick Pile section, the most complete in the study area, includes the uppermost Carnian Macrolobatus Zone, which provides conodont faunas of the lower primitia zone and Halobia septentrionalis. The 200-m thick lowermost Norian Kerri Zone, which begins 52 m above the Macrolobatus Zone, yields conodonts of the upper primitia zone in its lower part, together with H. cf. beyrichi and H. cf. selwyni. The ichthyosaur-bearing interval, whose stratigraphic position has been interpreted quite differently by previous authors, is documented in the uppermost Carnian Macrolobatus Zone and is characterized by rich Tropites-dominated ammonoid faunas and by the onset of Halobia. All models proposed by various workers to explain the unusual ichthyosaur record are discussed and an additional explanation for the main ichthyosaur-bearing bed is proposed. The new hypothesis is that a harmful algal bloom (HAB) may have been the trigger for the mass mortality recorded in this level. Although the C/N boundary in the Brick Pile section lies within a 52 m interval that presently lacks paleontologic data, this succession is included in a small group of sections that are expected to contribute to the definition of the GSSP of the Norian stage. Correlation of the Brick Pile section with the best Carnian/Norian sections in northeastern British Columbia is discussed. Compared to the British Columbia Juvavites Cove and the GSSP candidate Black Bear Ridge sections, the Brick Pile section exhibits an ammonoid and Halobia record that is slightly more similar to that of the Tethyan sections. Correlation of the Brick Pile section with the second GSSP candidate Pizzo Mondello (Sicily, Italy) well demonstrates the significant problems encountered in calibration of the Tethyan and North American scales

    SciQL, Bridging the Gap between Science and Relational DBMS

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    Scientific discoveries increasingly rely on the ability to efficiently grind massive amounts of experimental data using database technologies. To bridge the gap between the needs of the Data-Intensive Research fields and the current DBMS technologies, we propose SciQL (pronounced as ‘cycle’), the first SQL-based query language for scientific applications with both tables and arrays as first class citizens. It provides a seamless symbiosis of array-, set- and sequence- interpretations. A key innovation is the extension of value-based grouping of SQL:2003 with structural grouping, i.e., fixed-sized and unbounded groups based on explicit relationships between elements positions. This leads to a generalisation of window-based query processing with wide applicability in science domains. This paper describes the main language features of SciQL and illustrates it using time-series concepts

    A case for image quering through image spots

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    We present an image spot query technique as an alternative for content-based image retrieval based on similarity over feature vectors. Image spots are selective parts of a query image designated by users as highly relevant for the desired answer set. Compared to traditional approaches, our technique allows users to search image databases for local (spatial, color and color transition) characteristics rather than global features. When a user query is presented to our search engine, the engine does not impose any (similarity, ranking, cutoff) policy of its own on the answer set; it performs an exact match based on the query terms against the database. Semantic higher concepts such as weighing the relevance of query terms, is left to the user as a task while refining their query to reach the desired answer set. Given the hundreds of feature terms involved in query spots, refinement algorithms are to be encapsulated in separate applications, which act as an intermediary between our search engine and the users
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