92,931 research outputs found

    Color Image Processing for Space Shuttle Main Engine (SSME) Flaw Detection

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    Health monitoring of the SSME includes manual and robotic inspection of main injector components. Current automated visual tasks include scratch, crack, and erosion detection for oxidizer posts and injector faceplate. This paper discuses extending current visual tasks into the development of color segmentation and clustering algorithms to isolate and extract distinct discoloring flaws. A color image is represented by the combination of the primary colors red, green, and blue (RGB). The processing of the primary colors, individually or in groups, and the transformation into other color domains will be discussed. Finally, the applicability of color processing to the segmentation of color flawed SSME images will be discussed. @ Copyright 1993 by Bryan Everding and William G. Wee. Published by the University of Cincinnati with permission. 1.0 Automated Visual Inspection of SSME The SSME is a reusable rocket system requiring inspection after every use. Maintenance inspection is time cons..

    Dispelling the Myths Behind First-author Citation Counts

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    We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more sophisticated methods

    Author, publisher and bookseller : a tripartite synergy in Nigerian book industry

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    This work is about the roles of Author, Publisher and Bookseller in Book development in Nigeria. The paper started by delving into the history of Book Publishing in Nigeria after which it proceeded by defining who an author, a publisher, and a bookseller is and expatiated on the indispensable roles of these key actors in Nigerian Book Industry and in the emerging Information Society. Furthermore, the various constraints to book development were identified while the paper advised on how the Book Industry can be further promoted in Nigeria. However, the paper concluded and made recommendations on how the Book sector can help in enhancing scholarship in the country

    Author inscription in The Chinese slave-girl: a story of woman's life in China

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    This edition includes a gift inscription by author Rev. J.A. Davis, "To Rev. A. G. Russell with the warmest regards of the author J.A. Davis."Davis, John Agnell, 1839-1897

    G-Rank: Unsupervised Continuous Learn-to-Rank for Edge Devices in a P2P Network

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    Ranking algorithms in traditional search engines are powered by enormous training data sets that are meticulously engineered and curated by a centralized entity. Decentralized peer-to-peer (p2p) networks such as torrenting applications and Web3 protocols deliberately eschew centralized databases and computational architectures when designing services and features. As such, robust search-and-rank algorithms designed for such domains must be engineered specifically for decentralized networks, and must be lightweight enough to operate on consumer-grade personal devices such as a smartphone or laptop computer. We introduce G-Rank, an unsupervised ranking algorithm designed exclusively for decentralized networks. We demonstrate that accurate, relevant ranking results can be achieved in fully decentralized networks without any centralized data aggregation, feature engineering, or model training. Furthermore, we show that such results are obtainable with minimal data preprocessing and computational overhead, and can still return highly relevant results even when a user’s device is disconnected from the network. G-Rank is highly modular in design, is not limited to categorical data, and can be implemented in a variety of domains with minimal modification. The results herein show that unsupervised ranking models designed for decentralized p2p networks are not only viable, but worthy of further research.https://github.com/awrgold/G-RankComputer Scienc

    A Relational Unsupervised Approach to Author Identification

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    In the last decades speaking and writing habits have changed. Many works faced the author identification task by exploiting frequencybased approaches, numeric techniques or writing style analysis. Following the last approach we propose a technique for author identification based on First-Order Logic. Specifically, we translate the complex data represented by natural language text to complex (relational) patterns that represent the writing style of an author. Then, we model an author as the result of clustering the relational descriptions associated to the sentences. The underlying idea is that such a model can express the typical way in which an author composes the sentences in his writings. So, if we can map such writing habits from the unknown-author model to the known-author model, we can conclude that the author is the same. Preliminary results are promising and the approach seems viable in real contexts since it does not need a training phase and performs well also with short texts

    Nd-doped polarization maintaining all-fiber laser with dissipative soliton resonance mode-locking at 905 nm

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    Funding Information: Manuscript received February 15, 2021; revised May 14, 2021; accepted May 27, 2021. Date of publication June 1, 2021; date of current version September 13, 2021. This work was supported by RFBR under Grant 20-32-90233. (Corresponding author: Aram A. Mkrtchyan.) Aram A. Mkrtchyan, Yuriy G. Gladush, and Kirill A. Sitnik are with the Skolkovo Institute of Science and Technology, Moscow 121205, Russia (e-mail: [email protected]; [email protected]; [email protected]). Publisher Copyright: © 1983-2012 IEEE.Moving the fiber laser emission to the region below one micron may provide a cheaper, more compact and robust alternatives to the existing solid state lasers. Here, for the first time we report a neodymium mode-locked fiber laser emitting at 905 nm in the all-fiber polarization maintaining configuration. We obtain a self-starting pulse generation in nonlinear amplifying loop mirror (NALM) cavity configuration. To suppress a dominant emission at 1064 nm corresponding to a 4-level laser scheme, we use an active fiber - 920/1064 division multiplexer - active fiber sandwich-like sequence in the NALM loop. A rectangular shape dissipative soliton had nJ energy, 30 pm spectral width and 80 ÷ 430 ps width linearly depending on the pump power. Excellent agreement with numerical simulation allowed us to recover pulse shape and width for the pulses out of autocorrelation window.Peer reviewe

    Investigation of a flow field generated by a fractal grid based on experimental data and CFD simulations

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    Fractal grids generate turbulence by directly exciting many length-scales of different sizes simultaneously, rather than using the nonlinear cascade mechanism to obtain multiscale excitation, as it is the case for classical grids. These scales influence each other and show very different properties compared to all previously documented turbulent flows. In this work we present experimental wind tunnel and computer fluid dynamics (CFD) studies of the turbulent flow generated by a fractal grid under the same conditions. We did an extensive statistical study and a direct comparison between the experimentally and numerically acquired time series in order to investigate and compare one-point- and two-point-statistics. In addition we present an application of a stochastic method, so-called Langevin approach, to the experimentally and numerically acquired velocity increment time series to examine three-point-statistics in terms of Kramers-Moyal coefficients
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