169,991 research outputs found
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
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
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
An example of program evaluation project in undergraduate medical education
No full textRevisions to existing program evaluation approaches of the Dokuz Eylul University School of Medicine (DEUSM) were made by the Medical Education Department in June 2005. After considering several evaluation models, a mixed evaluation model was developed to meet institutional needs. The general program evaluation plan was structured as areas of inquiry under the three main program evaluation questions: what are the effects of the educational program on students and graduates, what are the effects of the educational program on trainers, and is the educational program being implemented as planned. The School's first report made through its new program evaluation approach was prepared in July 2006, leading to important revisions to the educational program. This article presents DEUSM's project to revise its program evaluation approach and briefly discusses its early implementation. © B Musal, C Taskiran, Y Gursel, S Ozan, S Timbil, S Velipasaoglu, 2008
A 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
A ±25A Versatile Shunt-Based Current Sensor with 10kHz Bandwidth and ±0.25% Gain Error from -40°C to 85°C Using 2-Current Calibration
No full textAccurate current sensing is critical in many industrial applications, such as battery management and motor control. Precise shunt-based current sensors have been reported with gain errors of less than 1% over the industrial temperature range (-40°C to 85°C) [1]–[4]. However, since they are intended for coulomb counting, their bandwidth is limited to a few tens of Hz, making them unsuitable for battery impedance or motor-current sensing. This paper presents a current sensor with a wide (10kHz) bandwidth and a tunable temperature compensation scheme (TCS), which allows it to be flexibly used with different types of shunts while maintaining high accuracy. A low-cost room-temperature calibration scheme is proposed to optimize gain flatness over temperature by exploiting the shunt's self-heating at large currents. Over the industrial temperature range and a ±25A current range, it achieves state-of-the-art gain error (±0.25%) with both low-cost PCB and stable metal-alloy shunts.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
Model predictive temperature control of a screw extruder
No full textDie vorliegende Arbeit beschäftigt sich mit der modellprädiktiven Regelung (MPC = Model Predictive Control) der Temperaturen eines Schneckenextruders. Die Aufgabe eines Extruders ist es, aus dem eingefüllten Granulat eine Schmelze zu erzeugen und fördert diese für die Verarbeitung zur nächsten Maschine. Dafür wurde ein thermisches Modell herangezogen, welches mittels Finite-Volumina-Methode hergeleitet wurde. Mit Hilfe dieser Regelung wird nun die Temperatur des Extruderzylinders auf eine vorgegebene Temperatur gebracht, um ein qualitatives Produkt zu erhalten. Da bei einem MPC stets eine Optimierungsaufgabe im Hintergrund gelöst wird, wird zuerst die vorliegende Problemstellung analysiert und untersucht, um festzustellen, welches Optimierungsverfahren mit der dazugehörigen Gütefunktion und den Nebenbedingungen zum gewünschten Ziel führt. Danach wird eine passende Softwarebibliothek zur Lösung der entsprechenden Optimierungsaufgabe gefunden, damit eine simulative Analyse und eine Implementierung auf einer Hardware möglich wird. Nach der Analyse in einer Simulationsumgebung wird der Regler an einem Workstation-PC mit Echtzeit-Patch mit der Programmiersprache C++ realisiert und getestet. Abschließend wird anhand Extrusionsexperimente an dem industriellen Extruder der modellprädiktive Regler validiert und mit dem bereits implementierten Regler verglichen.This thesis deals with the model predictive control (MPC) of the temperatures of a screw extruder. The task of an extruder is to produce a melt from the filled granulate and conveys it to the next machine for processing. For this purpose, a thermal model was used, which was derived using the finite volume method. With the help of this control, the temperature of the extruder cylinder is now brought to a specified temperature in order to obtain a qualitative product. Since there is always an optimisation task being solved in the background of an MPC, the problem at hand is first analyzed and investigated to determine which optimisation method with the associated quality function and constraints leads to the desired goal. Afterwards, a suitable software library for solving the corresponding optimisation task is found so that a simulative analysis and an implementation on a hardware becomes possible. After the analysis in a simulation environment, the controller is implemented using the programming language C++ and tested on a workstation PC with real-time patch. Finally, the model predictive controller is validated by using extrusion experiments on the industrial extruder and compared with the already implemented controller.eingereicht von Samet Taskiran, BScAbweichender Titel laut Übersetzung der Verfasserin/des VerfassersMasterarbeit Universität Linz 202
Model predictive temperature control of a screw extruder
No full textDie vorliegende Arbeit beschäftigt sich mit der modellprädiktiven Regelung (MPC = Model Predictive Control) der Temperaturen eines Schneckenextruders. Die Aufgabe eines Extruders ist es, aus dem eingefüllten Granulat eine Schmelze zu erzeugen und fördert diese für die Verarbeitung zur nächsten Maschine. Dafür wurde ein thermisches Modell herangezogen, welches mittels Finite-Volumina-Methode hergeleitet wurde. Mit Hilfe dieser Regelung wird nun die Temperatur des Extruderzylinders auf eine vorgegebene Temperatur gebracht, um ein qualitatives Produkt zu erhalten. Da bei einem MPC stets eine Optimierungsaufgabe im Hintergrund gelöst wird, wird zuerst die vorliegende Problemstellung analysiert und untersucht, um festzustellen, welches Optimierungsverfahren mit der dazugehörigen Gütefunktion und den Nebenbedingungen zum gewünschten Ziel führt. Danach wird eine passende Softwarebibliothek zur Lösung der entsprechenden Optimierungsaufgabe gefunden, damit eine simulative Analyse und eine Implementierung auf einer Hardware möglich wird. Nach der Analyse in einer Simulationsumgebung wird der Regler an einem Workstation-PC mit Echtzeit-Patch mit der Programmiersprache C++ realisiert und getestet. Abschließend wird anhand Extrusionsexperimente an dem industriellen Extruder der modellprädiktive Regler validiert und mit dem bereits implementierten Regler verglichen.This thesis deals with the model predictive control (MPC) of the temperatures of a screw extruder. The task of an extruder is to produce a melt from the filled granulate and conveys it to the next machine for processing. For this purpose, a thermal model was used, which was derived using the finite volume method. With the help of this control, the temperature of the extruder cylinder is now brought to a specified temperature in order to obtain a qualitative product. Since there is always an optimisation task being solved in the background of an MPC, the problem at hand is first analyzed and investigated to determine which optimisation method with the associated quality function and constraints leads to the desired goal. Afterwards, a suitable software library for solving the corresponding optimisation task is found so that a simulative analysis and an implementation on a hardware becomes possible. After the analysis in a simulation environment, the controller is implemented using the programming language C++ and tested on a workstation PC with real-time patch. Finally, the model predictive controller is validated by using extrusion experiments on the industrial extruder and compared with the already implemented controller.eingereicht von Samet Taskiran, BScAbweichender Titel laut Übersetzung der Verfasserin/des VerfassersMasterarbeit Universität Linz 202
An Article About Albertus C. Van Raalte, Author Unknown, Except for Parts Taken from an Article by Anna C. Post
No full textAn article about Albertus C. Van Raalte, author unknown, except for parts taken from an article by Anna C. Post. The author knew first generation persons in the Holland settlement and therefore, the article has some value.https://digitalcommons.hope.edu/vrp_1890s/1012/thumbnail.jp
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