169,893 research outputs found
Improving Link Quality Estimation Accuracy in 6TiSCH Networks
No full textThe Industrial Internet of Things (IIoT) will leverage on wireless network technologies to integrate in a seamless manner Cyber-Physical Systems into existing information systems. In this context, the 6TiSCH architecture, proposed by IETF, represents the current leading standardization effort to enable timed and reliable data communication within IPv6 networks for industrial applications. In wireless networks, Link Quality Estimation (LQE) is a crucial task to select the best routes for data forwarding, regardless of unpredictable time varying conditions. Although, many solutions for LQE have been proposed in literature, the majority of them are not designed specifically for 6TiSCH networks. In this paper, we analyze the performance of existing LQE strategies on 6TiSCH networks. First, we run a set of simulations to measure the performance of one existing LQE strategy in 6TiSCH. Our simulations show that such strategy can result in measurements with low accuracy due to the 6TiSCH default timeslot allocation strategy. Consequently, we propose an extension of the 6TiSCH Minimal Configuration that allocates specific timeslots for the transmission of probing messages to mitigate the problem. The proposed methodology is demonstrated to effectively reduce the LQE error
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Ermittlung der Gebrauchseigenschaften der 600 C-Staehle fuer Dampfturbinen (DT1/2). Teilvorhaben: Mikrostrukturelle Untersuchungen zum Langzeitverhalten Abschlussbericht
No full textMicrostructural analyses were carried out by TEM. The data will be used for modelling the material characteristics on a microstructural basis.In dem Teilvorhaben ging es darum, die mikrostrukturelle Grundlage der Gebrauchseigenschaften der 600 C-Staehle zu klaeren. Die fuer die Eigenschaften entscheidenden mikrostrukturellen Elemente in Form von Kristall-Versetzungen und harten Ausscheidungen liegen mit ihren Abmessungen im Submikrometerbereich. Zu ihrer Sichtbarmachung ist Transmissionselektronenmikroskopie (TEM) Voraussetzung. Erst durch die Sichtbarmachung dieser mikrostrukturellen Elemente lassen sich die in den anderen Teilvorhaben ermittelten Gebrauchseigenschaften verstehen und bewerten. Geplant war darueber hinaus, die mikrostrukturellen Daten fuer eine Modellierung des Verhaltens auf mikrostruktureller Basis zu nutzen. (orig.)Available from TIB Hannover: DtF QN1(97,9) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Regelloses Zeitstandverhalten. Verhalten warmfester Staehle bei regelloser Zeitstandbeanspruchung Abschlussbericht
No full textThe response of high-temperature steels to random long-term stress was investigated using the specially developed software LARA S. The generalized damage accumulation hypothesis was used for describing the material response to random long-term stress. With this, long-term stress damage can be calculated on the basis of the modified life fraction rule and fatigue damage with the aid of the Miner rule. An analysis of operating logs provided information on one-stage and multistage partial stress cycles with and without pressure phases. For the steels X10CrMoVNb9-1 and X3CrNiMoN17-13, the fatigue characteristics for single-stage stress was described using the factor concept. For these two steels, and also for the steels X12CrNiMoWVNbN10-1-1 and G17CrMoV5-11, the description of the material response to multistage stress was validated experimentally using the step hypothesis. The influence of limited and enhanced pressure phases was analyzed as well. The life predictions of LARA S were verified by random fatigue tests with varied temperature and stress up to 500 h on the steels 28CrMoNiV4-9, X21CrMoV12-1, and X12CrNiMoWVNbN10-1-1. For this purpose, the load curves derived from operating records were enhanced with a view to the stress and temperature over time. The comparison of predicted and experimental results illustrates the applicability of LARA S with the given concepts. (orig.)Das Vorhaben befasst sich mit dem Werkstoffverhalten bei regelloser Zeitstandbeanspruchung von warmfesten Staehlen fuer den thermischen Maschinen-und Anlagenbau. Es wurde ein Lebensdauerzaehlerprogramm LARA S entwickelt, das regellose Zeitstandbeanspruchung mit gelegentlichen auftretenden ueberelastischen Beanspruchungen behandelt. Zur Beschreibung des Werkstoffverhaltens unter regelloser Zeitstandbeanspruchung wurde die verallgemeinerte Schadensakkumulationshypothese eingesetzt. Mit ihr lassen sich rechnerische Zeitstandschadensanteile auf Basis der modifizierten Lebensdaueranteilregel und rechnerische Ermuedungsschadensanteile mit Hilfe der Miner-Regel erfassen. Aus der Analyse von Betriebsaufzeichnungen liessen sich ein- und mehrstufige Teilbeanspruchungszyklen ohne und mit Druckphasen ableiten. An den Staehlen X10CrMoVNb9-1 und X3CrNiMoN17-13 wurde das Zeitstandverhalten bei einstufiger Beanspruchung mit dem Faktorenkonzept beschrieben. Fuer diese beiden Staehle und darueber hinaus fuer die Staehle X12CrNiMoWVNbN10-1-1 und G17CrMoV5-11 wurde die Beschreibung des Werkstoffverhaltens bei mehrstufiger Beanspruchung mit der Schritthypothese experimentell abgesichert. Des Weiteren wurde der Einfluss von begrenzten und ausgepraegten Druckphasen untersucht. Zur Verifikation dermit LARA S vorhergesagten Lebensdauer wurden regellose Zeitstandversuche mit veraenderter Temperatur und Spannung bis rd. 5000 h an den Staehlen 28CrMoNiV4-9, X21CrMoV12-1 und X12CrNiMoWVNbN10-1-1 durchgefuehrt. Zu diesem Zweck wurden die aus Betriebsaufzeichnungen abgeleiteten Beanspruchungsverlaeufe hinsichtlich Spannungs- und Temperatur-Zeit-Verlauf erhoeht. Aus dem Vergleich von Vorhersage und Experiment laesst sich die Anwendbarkeit von LARA S mit den angegebenen Konzepten erkennen. (orig.)SIGLEAvailable from TIB Hannover: RA 2383(269) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekForschungsvereinigung der Arbeitsgemeinschaft der Eisen- und Metallverarbeitenden Industrie e.V. (AVIF), Duesseldorf (Germany)DEGerman
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
OCC Memorandum from Daniel Staehle to Ronald Frake Re North America Credit Trading and North America Global Structured Credit Derivatives Examination
No full textA Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
A 0.12mm<sup>2</sup> Wien-Bridge Temperature Sensor with 0.1°C (3σ) Inaccuracy from -40°C to 180°C
No full text Resistor-based temperature sensors can achieve much higher resolution and energy efficiency than conventional BJT-based sensors [1], but they typically occupy more area (> 0.25 mm 2 ) and have lower operating temperatures (le 125 {circ} {C}) [2]-[4]. This work describes a 0.12mm 2 resistor-based sensor that uses a Wien-bridge (WB) filter to achieve 0.1 {circ} {C} (3 sigma) inaccuracy from - 40 {circ} {C} to 180 {circ} {C}. Compared to a state-of-the-art WB sensor [4], it occupies 6 × less area and achieves comparable relative accuracy over a 76% wider operating range. Session 10.3 Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
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