50 research outputs found
Answering Non-Monotonic Queries in Relational Data Exchange
Relational data exchange is the problem of translating relational data from a
source schema into a target schema, according to a specification of the
relationship between the source data and the target data. One of the basic
issues is how to answer queries that are posed against target data. While
consensus has been reached on the definitive semantics for monotonic queries,
this issue turned out to be considerably more difficult for non-monotonic
queries. Several semantics for non-monotonic queries have been proposed in the
past few years. This article proposes a new semantics for non-monotonic
queries, called the GCWA*-semantics. It is inspired by semantics from the area
of deductive databases. We show that the GCWA*-semantics coincides with the
standard open world semantics on monotonic queries, and we further explore the
(data) complexity of evaluating non-monotonic queries under the
GCWA*-semantics. In particular, we introduce a class of schema mappings for
which universal queries can be evaluated under the GCWA*-semantics in
polynomial time (data complexity) on the core of the universal solutions.Comment: 55 pages, 3 figure
Effectiveness of photodynamic therapy for mammary and extra-mammary Paget's disease: a state of the science review
<p>Abstract</p> <p>Background</p> <p>Paget's disease is a rare skin disorder occurring in the breast (mammary) or in the groin, genital, peri-anal and axillary regions (extra-mammary). Typical treatment involves surgical excision, which in the case of extra-mammary Paget's disease, can lead to significant morbidity. Photodynamic therapy (PDT) which uses a topical or intravenous photosensitizing agent that is activated by a light source to ablate abnormal tissue, offers a minimally invasive alternative. The purpose of this study was to assess the effectiveness of photodynamic therapy in the treatment of Paget's disease.</p> <p>Methods</p> <p>Following Cochrane guidelines, a comprehensive systematic review of all clinical studies and reports examining the use of PDT for mammary and extra-mammary Paget's disease was conducted. Study quality was assessed using the Oxford Levels of Evidence Scale.</p> <p>Results</p> <p>21 retrospective and 2 prospective non-comparative studies were identified and included in the review: 9 case reports with 1-2 patients and 14 case series with 1-16 patients. These reports totalled 99 patients with 133 extra-mammary Paget's lesions and 3 patients (with 3 lesions) with mammary Paget's disease. Follow-up periods were typically one year or less, with 77/133 extra-mammary lesions exhibiting complete response to PDT. One recurrent mammary skin lesion and two mammary lesions treated concomitantly with surgery also exhibited complete responses.</p> <p>Conclusions</p> <p>Evidence of the effectiveness of PDT for Paget's disease is promising, but limited. This may, in part, be explained by the rarity of the condition, making controlled comparative clinical trials challenging.</p
Business Case Valuation of Strategic Flexibility in Ship Building: Justifying and Assessing the Value of Flexible Ships Design Features in New Navy Ship Concepts
To successfully implement the Surface Navy's Flexible Ships concept, Program Executive OfficeヨShips (PEO-SHIPS) requires a new methodology that assesses the total future value of various combinations of Flexible Ships design features and how they will enable affordable warfighting relevance over the ship's full service life. Examples of Flexible Ships design features include decoupling payloads from platforms, standardizing platform-to-payload interfaces, implementing allowance for rapid reconfiguration of onboard electronics and weapons systems, preplanning access routes for mission bays and mission decks, and allowing for sufficient growth margins for various distributed systems. This research analyzes the application of strategic Real Options Valuation (ROV) methodology within the Integrated Risk Management process to assess the total future value of Flexible Ships design features and for use in the Future Surface Combatant Analysis of Alternatives. The current research has the explicit goal of proposing a reusable, extensible, adaptable, and comprehensive advanced analytical modeling process to help the U.S. Navy in quantifying, modeling, valuing, and optimizing a set of ship design options to create and value a business case for making strategic decisions under uncertainty.Naval Postgraduate School Acquisition Research Progra
A corrected identification and a new combination for a recent Florida introduction: Agaloma graminea (Euphorbiaceae)
Volume: 89Start Page: 225End Page: 22
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Network analyzer calibration for cryogenic on-wafer measurements
A cryogenic probe station for on-wafer microwave measurements has been developed at Sandia National Laboratories to explore the basic device physics and characterize advanced components for low-temperature applications. The station was designed to operate over a temperature range of 20 to 300 K with a frequency range of DC to 50 GHz. Due to the vacuum and the low temperature environment, the use of microwave probes and the calibration of network analyzer measurements are somewhat elaborate. This paper presents guidelines for probe use and calibration in this environment