78,373 research outputs found

    A Formal Framework for Linguistic Annotation

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    `Linguistic annotation' covers any descriptive or analytic notations applied to raw language data. The basic data may be in the form of time functions -- audio, video and/or physiological recordings -- or it may be textual. The added notations may include transcriptions of all sorts (from phonetic features to discourse structures), part-of-speech and sense tagging, syntactic analysis, `named entity' identification, co-reference annotation, and so on. While there are several ongoing efforts to provide formats and tools for such annotations and to publish annotated linguistic databases, the lack of widely accepted standards is becoming a critical problem. Proposed standards, to the extent they exist, have focussed on file formats. This paper focuses instead on the logical structure of linguistic annotations. We survey a wide variety of existing annotation formats and demonstrate a common conceptual core, the annotation graph. This provides a formal framework for constructing, maintaining and searching linguistic annotations, while remaining consistent with many alternative data structures and file formats.Comment: 49 page

    ITERL: A Wireless Adaptive System for Efficient Road Lighting

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    This work presents the development and construction of an adaptive street lighting system that improves safety at intersections, which is the result of applying low-power Internet of Things (IoT) techniques to intelligent transportation systems. A set of wireless sensor nodes using the Institute of Electrical and Electronics Engineers (IEEE) 802.15.4 standard with additional internet protocol (IP) connectivity measures both ambient conditions and vehicle transit. These measurements are sent to a coordinator node that collects and passes them to a local controller, which then makes decisions leading to the streetlight being turned on and its illumination level controlled. Streetlights are autonomous, powered by photovoltaic energy, and wirelessly connected, achieving a high degree of energy efficiency. Relevant data are also sent to the highway conservation center, allowing it to maintain up-to-date information for the system, enabling preventive maintenance.Consejería de Fomento y Vivienda Junta de Andalucía G-GI3002 / IDIOFondo Europeo de Desarrollo Regional G-GI3002 / IDI

    Connectivity Oracles for Graphs Subject to Vertex Failures

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    We introduce new data structures for answering connectivity queries in graphs subject to batched vertex failures. A deterministic structure processes a batch of ddd\leq d_{\star} failed vertices in O~(d3)\tilde{O}(d^3) time and thereafter answers connectivity queries in O(d)O(d) time. It occupies space O(dmlogn)O(d_{\star} m\log n). We develop a randomized Monte Carlo version of our data structure with update time O~(d2)\tilde{O}(d^2), query time O(d)O(d), and space O~(m)\tilde{O}(m) for any failure bound dnd\le n. This is the first connectivity oracle for general graphs that can efficiently deal with an unbounded number of vertex failures. We also develop a more efficient Monte Carlo edge-failure connectivity oracle. Using space O(nlog2n)O(n\log^2 n), dd edge failures are processed in O(dlogdloglogn)O(d\log d\log\log n) time and thereafter, connectivity queries are answered in O(loglogn)O(\log\log n) time, which are correct w.h.p. Our data structures are based on a new decomposition theorem for an undirected graph G=(V,E)G=(V,E), which is of independent interest. It states that for any terminal set UVU\subseteq V we can remove a set BB of U/(s2)|U|/(s-2) vertices such that the remaining graph contains a Steiner forest for UBU-B with maximum degree ss

    Advanced periodic maintenance scheduling methods for aircraft lifecycle management

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    This paper reviews existing methods and techniques addressing the problem of maintenance support throughout the life cycle for high value manufacturing products such as aircrafts. As part of this doctorate research the analysis of current methods of maintenance scheduling was conducted. In order to contribute to a more comprehensive solution, an advanced approach (algorithm) of periodic maintenance is presented. The authors believe that this approach will reduce the cost of maintenance of high value manufacturing products. The algorithm based on constraint programming methods is briefly presented and the future research directions are discussed
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