286,937 research outputs found
A Note on the Ky Fan Inequality
No full textThe Ky Fan inequality is essentially the assertion that t/(1−t) is log-concave. We study its weighted form in the context of signed weights
Using performance assessment in secondary school mathematics: an empirical study in a Singapore classroom
No full textThis article reports an exploratory study on using performance assessment in mathematics instruction in a high-performing secondary school in Singapore. An intact mathematics class participated in the study, and received chapter-based performance tasks as intervention during regular mathematics lessons for about one and a half school years. The performance tasks used included authentic and/or open-ended tasks. The students’ academic achievements and attitudes in mathematics were compared with a comparison class that did not receive the intervention. Both quantitative and qualitative data were collected, mainly through questionnaire surveys, performance task tests, conventional school exams, and interviews with students and teachers. The results suggest that the students receiving the intervention performed significantly better than their counterparts in solving conventional exam problems, and in general they also showed more positive changes in attitudes towards mathematics and mathematics learning. The students from the experimental class also expressed positive views about the benefits of using performance tasks in promoting their ability in higher order thinking, though no statistically significant difference was detected between the two classes of students in solving unconventional tasks before and after intervention. Overall, the results appear to support teachers’ using contextualised problems in real life situations and open-ended investigations in students’ learning of mathematic
On the Ky Fan Inequality
No full textSome inequalities related to the Ky Fan and C.-L. Wang inequalities for weighted arithmetic and geometric means are given
Richardson, Barbauld, and the construction of an early modern fan club
No full textMPhilMuch has been written about the life and long works of the eighteenth century epistolary novelist, Samuel Richardson, but the prospect of his position as the first celebrity novelist – responsible for courting his own fame as well as initiating his own fan club – has largely been ignored. The body of manuscripts housed at the National Art Library in the Victoria and Albert Museum in London provides the modern scholar with evidence of the skeletal beginnings of an early fan club. This thesis aims to show how these manuscripts were turned into a saleable commodity by the publisher and entrepreneur Richard Phillips, while under the guiding hand of another, slightly later, literary celebrity, Anna Laetitia Barbauld. In order to restore Richardson’s reputation amongst a new nineteenth century audience, Barbauld was required to construct her own idea of him as an eighteenth century celebrity author, and in doing so the insecurities of a self-professed, apparently diffident man, are revealed. Barbauld’s capacious, but heavily edited selection of letters is analyzed in this thesis, providing ample evidence that Richardson’s correspondents were more than just eager letter writers. By using Barbauld’s biography of Richardson this thesis aims to show how she manipulates the genre of life writing in her construction of him.
This thesis offers an alternative reading of how the Richardson manuscripts are viewed, redefining them as not simply a collection of letters, but as a collective entity, deliberately selected and archived as evidence of an early modern fan club, and its celebrity managing director
The art of fan-painting /
No full text"Lechertier, Barbe & Co. A price list of colours and sundries used in fan painting. 1880": p. [33]-85.Mode of access: Internet
Use of fan rig data for the understanding and prediction of fan broadband noise and noise changes due to a variable area nozzle
No full textThis thesis presents the results of the research component of this EngD, entitledUse of fan rig data for the understanding and prediction of fan broadband noise and noisechanges due to a variable area nozzleAs suggested by the title, fan rig noise measurements form an integral part of this thesis. Theanalysis of a database of rig noise measurements forms the first section of this thesis, in twoparts. The first part describes the analysis of a set of fan rig noise measurements, including thevariation of fan broadband and tone noise in forward and rearward arcs. The second partexamines a large database of fan rig noise measurements, and attempts to derive correlationsof fan broadband noise and fan performance parameters. Cluster Analysis, PrincipleComponent Analysis, and Regression Analysis are used to understand and describe theunderlying physics of broadband noise generation and the relationships between thesepredictors.The second section of this thesis uses a cascade broadband noise model to investigate rotorstatorbroadband noise. Predictions of the broadband noise from this noise model arecompared to rig measurements, showing good accuracy. The underlying physics of rotorstatorbroadband noise generation is investigated by performing two parametric studies usingthe broadband noise model. The first parametric study investigates the effect on broadbandnoise of simple flow and geometric parameters, namely number of vanes, vane chord, vanestagger angle, and rotor wake turbulence intensity, turbulent length scale, and flow Machnumber onto the cascade. These results are used to derive scaling power laws for theprediction of changes in broadband noise due to changes in these parameters. The secondparametric study expands upon this by investigating the effect on broadband noise of the fandesign parameters shaft speed, pressure ratio, and efficiency, at approach, cutback and cruiseconditions. The variation in broadband noise due to these design parameters is explained byconsidering the underlying flow and geometric parameters such as number of vanes and Machnumber, and the scaling power laws based on these simple parameters are used to predict thechange in broadband noise between different performance points.The final section of this thesis investigates the effect of varying exhaust nozzle area on totalengine noise. A new method is presented that allows the transfer of changes in fan rig noise toEugene P. Deane EngD Thesis September 2009 2engine noise predictions, to estimate the change in fan noise due to the pressure ratio changesbrought about by a variable area nozzle. Changes in engine noise are investigated forapproach, cutback, and sideline conditions, and the application of the new method assessed.As the research displayed in this thesis is closely linked to industry, the foundation of workpresented in several chapters is dependent on data or figures that are commercially sensitive.It has therefore been necessary to create a confidential appendix (Appendix X) to includethese commercially sensitive items. These additional results and figures in Appendix X aresupplementary in nature, and sufficient results are presented in the public thesis to illustratethe results of the various chapters. Where supplementary information and results are available,this is clearly indicated at the pertinent point in the published thesis, along with the section ofAppendix X where the information can be found
Air and Water Flowrate Optimisation for a Fan Coil Unit in Heat Pump Systems
Get PDFThe degradation in efficiency of auxiliary components in heating/cooling systems when operating at part load is frequently reported. Through the use of variable speed components, the supplied capacity can be reduced to match the required load and hence reduce unnecessary energy consumption. However, for fan coil units, difficulties can arise when optimizing fan and pump speeds at part load. Practically locating optimal water and air flow rates from readily available information and for varying supplied capacities is necessary, in order to reduce the fan coil power consumption. This research attempts to identify whether optimal fan and pump speeds exist for a fan coil unit and how they can be implemented, in a practical manner, in a system control applications. Using an empirical fan coil and pump model, the total power consumption (fan and pump) for different combinations of fan and pump speeds over a range of capacities was calculated. It was observed that, for a given capacity, an optimal combination of fan and pump speeds exists and there was a significant change in power consumption for different combinations of fan and pump speeds supplying the same capacity. A control strategy is described that utilizes a simple fan coil capacity estimation model, coupled with air and water flow rates, along with nominal design data. The pump speed is optimized using PID control to maintain the space temperature at the chosen set-point, which matches the supplied capacity to the required capacity. At set-time intervals, the capacity estimation model is utilized to optimize the water and air flow rates for the required capacity. The control strategy is evaluated, using a full building simulation model for a daily load profile and is compared to two baseline conditions: for no control of the fancoils/pump combination and for PID circulation control of the pump only. The optimal fan and pump speed control resulted in a 43% and 24% decrease in power consumption with compared to the no control baseline and the PID controlled circulation pump strategy, respectively
On a Class of Ky Fan-Type Inequalities
No full textIn this paper, we study one class of Ky Fan-type inequalities, which has ties with the
original Ky Fan inequality. Our result extends the known ones
DESIGN OF FORWARD-INCLINED BLADES FOR A 0.5 HUB-TO-TIP RATIO TUBE-AXIAL FAN
No full textThe paper deals with the design of forward-inclined blades, where “forward-inclination” is intended as the design-dependent amount of forward sweep to be incorporated in non-free-vortex blades to restore a quasi-2D flow behaviour within the rotor passages. The aim of the work is to assess the effectiveness of this design modification in a 0.5 hub-to-tip ratio fan with radially stacked blades that induce a roughly constant-swirl velocity at the rotor exit. To this end, the original blade has been modified by incorporation of a forward sweep amount that translates into a forward-inclined design, defined in accordance with a method suggested by the authors. The forward-inclined design demonstrated experimentally to improve pressure rise and efficiency of the original fan in the whole operation range with ca 10% gain at design operation
A New Approach to Ky Fan-type Inequalities
No full textThe study of the behavior of means under equal increments of their variables provides a new approach to Ky Fan-type inequalities. Via this new approach we are able to prove some new results on Ky Fan-type inequalities
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