Analysis of selected problems involving vortical flows

Three selected problems involving vortical flows are analyzed and discussed including: the trailing vortex behind a wing; rotor blade-vortex interaction; and the leading edge vortex on a flat plate

Resources in Europe of interest to mathematics teachers,

Thesis (M.A.)--Boston University. This thesis was written in conjunction with Dennis J. Roberts, Mary Lee McLaughlin and Robert F. Pierce.Statement of the problem: It is the purpose of this thesis to formulate plans for a guided tour throughout Western Europe for secondary-school teachers with emphasis on present and past mathematical and allied science contributions. This study will serve as an answer to four fundamental questions: 1. What are the resources available in Europe of value to mathematics teachers? 2. From the standpoint of marginal utility, which of these would be the most important? 3. where are they to be found? 4. How long would it take to see each of them profitably in a limited amount of time? [TRUNCATED

Stability of Noisy Metropolis-Hastings

Pseudo-marginal Markov chain Monte Carlo methods for sampling from intractable distributions have gained recent interest and have been theoretically studied in considerable depth. Their main appeal is that they are exact, in the sense that they target marginally the correct invariant distribution. However, the pseudo-marginal Markov chain can exhibit poor mixing and slow convergence towards its target. As an alternative, a subtly different Markov chain can be simulated, where better mixing is possible but the exactness property is sacrificed. This is the noisy algorithm, initially conceptualised as Monte Carlo within Metropolis (MCWM), which has also been studied but to a lesser extent. The present article provides a further characterisation of the noisy algorithm, with a focus on fundamental stability properties like positive recurrence and geometric ergodicity. Sufficient conditions for inheriting geometric ergodicity from a standard Metropolis-Hastings chain are given, as well as convergence of the invariant distribution towards the true target distribution

Relationship between starting and finishing position in World Cup BMX racing

The BMX start is one of the most important aspects of BMX racing and has been deemed by coaches as one of the strongest determining factors of finish line placing. The present study analysed the correlation between elite BMX riders and their relative position at the start of a BMX race in relation to finish line placing. Data from 348 riders results in 175 elite races in the four 2012 Union Cycliste Internationale (UCI) world cup events were analysed. Time gates were placed in four positions around each BMX track and the data sets were analysed using Kendall's tau-b bivariante correlation. A strong correlation was established at the second time gate for both males (t=0.581, P<0.01) and females (t=0.571, P<0.01). The correlation between riders' final placing was greater in positions 1st to 3rd (t=0.586, P <0.01. 4th to 8th t=0.249, P <0.01) compared to riders placed 4th to 8th (t=0.519, P <0.01. 4th to 8th t=0.372, P <0.01.) for both male and female riders respectively. In conclusion, a strong correlation exists between riders position 8-10 s into a race. Therefore, focusing on a riders' ability to gain placings at the start of a race will have an effect on their finish line position.N/

Two blowing concepts for roll and lateral control of aircraft

Two schemes to modulate aerodynamic forces for roll and lateral control of aircraft have been investigated. The first scheme, called the lateral blowing concept, consists of thin jets of air exiting spanwise, or at small angle with the spanwise direction, from slots at the tips of straight wings. For this scheme, in addition to experimental measurements, a theory was developed showing the analytical relationship between aerodynamic forces and jet and wing parameters. Experimental results confirmed the theoretically derived scaling laws. The second scheme, which was studied experimentally, is called the jet spoiler concept and consists of thin jets exiting normally to the wing surface from slots aligned with the spanwise direction

Mammy\u27s lullaby : a dreamy southern waltz / by Lee S. Roberts ; with words by J. Will Callahan.

https://digitalcommons.library.umaine.edu/mmb-vp/2077/thumbnail.jp

Mammy\u27s Lullaby

[Verse 1]Close yoh dreamy eyes an’ lay yoh head on Mammy’s breat,Stahs ah in de skies an birds ah sleein’ in de nest,Night time is heah, honey don’t feah,Yoh on Mammy’s ahm;Great big yallah moon a shinin’ down upon de stream,Mammy’s little coon will soon be floatin’ in a dream,Slumabh ashile, mah honey chile,Yoh mammy will keep yoh from hahm, [Chorus]Go to sleep,Wiv yoh head in yoh mammy’s breastCause Mammy knows her dusky rose tiahed an’ longin’ fo’ rest;Go to sleep while de shadders creep,Des dream away till break ob day,An doan yoh eben peep [Verse 2]In dah sugah cane de owl’s a hootin’ to de moon,Down along de lane I heah de darkies softly cronn,Now hushabye, honey, don’t cry,But des close yoh eyes;When de mawnin’ come an’ all de birds begin to cheepMammy’s sugah plum a goin’ to waken from his sleepDes like a flow’h kissed by de show’h when rain drops come down from de skyYoh Mammy’s pickaniny,De finest an’ de best,De pride of old VirginnySo slumbah, my honey, an’ restGo to sleep,Go to sleep

Ching Chong

https://digitalcommons.library.umaine.edu/mmb-vp/2852/thumbnail.jp