169,831 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
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
DYNAMIC RESPONSE OF INELASTIC MULTI-STOREY BUILDING FRAMES
No full textThis thesis presents an analytical method based
on classical matrix methods for computing the dynamic
response of elastic-plastic multi-storey building frames.
The method developed is comparatively simple and is of
much use for building frames having large number of
storeys. By this method, response of multi-storey buildings could be calculated on high-speed digital computers
of high storage capacity. The computer program developed
saves huge storage locations and thus makes it possible
to analyze multi-storey frames which till now were considered as very difficult. Dynamic response of a two-storey and six-storey frame are shown to demonstrate the
utility of the method.ThesisMaster of Engineering (ME
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
Aerodynamic Shaping of a Propulsive Fuselage Concept: A Design Space Exploration
No full textBoundary layer ingestion is an airframe-propulsion integration technology capable of enhancing aircraft propulsive efficiency. The Propulsive Fuselage Concept, a tube-and-wing layout with an rear-fuselage-mounted propulsor in the boundary layer ingestion configuration, especially takes advantage this. However, the relation between physical shape and aerodynamic performance, resulting from the complex airframe-propulsor interaction, is not entirely understood. Also, contrary to long-haul aircraft, few studies have investigated the application of the concept on medium-haul aircraft with only 10% cruise thrust contribution coming from the boundary layer ingestion propulsor, which is a top-level requirement of the APPU project. To facilitate parametric studies regarding these research gaps, a parametric model is developed and implemented in an engineering design application that automates aerodynamic analysis to high degree. This thesis presents a methodology to numerically analyze axisymmetric propulsive fuselage concept designs; an engineering design application using the knowledge based engineering technology is presented that facilitates the implementation of complex engineering design rules in the construction of the parametric model. The application consist of three components. Firstly, a flexible geometric parameterization in 2D is developed that is proven capable of constructing well-performing designs. A translation mechanism is developed between these geometric input parameters and input parameters for class shape transformation curves, which form the mathematical basis for the geometry. Secondly, the construction of a C-shaped domain and a multi-block structured mesh are also automated in the application. The mesh density for this application was verified through a mesh convergence study, and can be adjusted to fit other mesh requirements through various mesh control capabilities. Lastly, the scripted interaction between the application and ANSYS Fluent software is automated. A fan modeling methodology was developed using boundary conditions that requires only fan pressure ratio as input, while mass flow continuity through the fan is ensured. The meshing and simulation routines are validated by comparing the results of the presented routine to that of a status-quo numerical simulation. All relevant aerodynamic output parameters show agreement in a range of 3.3%.The working of the engineering design application is demonstrated in a design space exploration based on the hypothesis that increased conicity of the rear fuselage and nacelle shape with respect to the longitudinal axis can reduce the required fan power in cruise conditions. To isolate the effect of conicity, a parameter sweep was conducted. Results show that with increasing conicity, the overall viscous dissipation was continuously reduced. Also the total pressure recovery at the fan inlet face increases up to a nacelle conical angle of 11 degrees, after which this decays due to increased wetted area. At 11 degrees conicity, the aerodynamic efficiency (defined as fan power required for a given net propulsive force) was increased by 0.81% relative to a less conical status-quo baseline design with 6 degrees conicity. The increased fuselage volume and wetted area due to increased conicity introduced the opportunity to shorten the fuselage without decreasing fuselage volume. This increased aerodynamic efficiency by 1.65% relative to the baseline. Also, as the intake diffusion functionality was redundant in this flow field, a third design was constructed with a 29% shorter intake duct, which increased aerodynamic efficiency by 1.81% compared to the baseline. Demonstrated by these unoptimized designs and the observed physical mechanisms, it is concluded that aerodynamic efficiency could benefit from the direct and indirect effects of an increase in conicity of the propulsive fuselage concept.APPU ProjectAerospace Engineerin
Archivist, Archaeologist, Author and the Tactile Window
No full textThe idea that the predominant way of engaging with architecture is through vision is not uncommon but also not always the most appropriate given that buildings are also experienced through tactile interventions. This consequence that emphasises visual aesthetics in order to appreciate and understand architecture probably has much to do with the assumed but rather vaguely defined role of the architect as designer in the practice of architectural design. A resulting misapprehension is that architects designing for visual appreciation think that they are actually designing physical space for embodied tactile engagement.
This prioritisation of vision in the way architects think about and approach design is questioned through the design project of the Tactile Window in which the position of the architect is redefined through inhabiting the roles of archivist, archaeologist and author during the design process.
A 16th century portrait of Queen Elizabeth I known as the Ditchley portrait, currently on display at the National Portrait Gallery is used as the source from which the design of the Tactile Window is derived from and refers back to. Questioning the validity of vision as the sole means of engaging with the work, information about the portrait and working methods gathered from the three carefully chosen positions mentioned above are drawn on and applied to the making of this Tactile Window that becomes an alternative Ditchley portrait. Through exploring the hidden historical and current narratives of and in the existing portrait, the presence of the portrait is alluded to on an alternative physical site. Key to this are the working methods of an invented archival system of design reasoning, the unearthing of archaeological texts and assuming of authorship within the individual frameworks of the roles of archivist, archaeologist and author.
The redefined role of the architect as archaeologist takes onboard the unearthing of associated drawings and writings as well as the methods of organising and applying the recovered information to the system set up by the archivist. This analysis of the graphic and text based information is used to formulate historical narratives that are woven into the design project. Whereas traditional archaeology stresses on the study of a site from a site with quantifiable limits to the physical context, the notion of archaeological sites in this instance refers to the places where the stored information is unearthed. Through the careful process of archiving and analysing this information, a new site that is located within both the physical and historical contexts of interest is discovered. The author then draws upon the elements in the archival system that includes the findings of the archaeologist to construct the alternative Ditchley portrait in this new site of the Echoing Cedar, the result of which bears no visual resemblance to the existing work.
The Tactile Window is a reading of the Ditchley portrait in which information about and in the painting is transformed into a design proposal for an inhabited structure. The intended method of interaction with this alternative portrait is not merely restricted to vision but relies on engagement with the other senses. This experience is enhanced by the interplay with certain site conditions such as wind and rain in order to allude to specific aspects of the Ditchley portrait that are not visually apparent in the existing work.
In the processes of excavating, finding and revealing the hidden information to create this alternative portrait, the effects of the visuals afforded by the existing portrait inadvertently begin to fade as the validity of a single means of visual expression is questioned
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