90 research outputs found
Optimal Skateboard Geometry for Maximizing Ollie Height: a Multi-Phase Direct Collocation Optimization Study
No full textSkateboarding involves a human controlling a four wheeled vehicle that is steered by tilting the standing surface. The riding mechanics of skateboarding have been well reported [2, 3]. The sport also includes aerial maneuvers such as jumping of stairs, flying off ramps and flipping and rotating the skateboard. The most basic aerial trick is called the ollie. The athlete jumps up while pushing down on the back end of the skateboard’s tail, causing a rotation about the back axle. The upward acceleration due to the rotation together with the tail-ground impact cause the skateboard to go airborne. Midair the athlete drags the skateboard up through frictional contact and levels it out to land the trick. The most concrete performance measure of the ollie is height according to the Olympic judging criteria [4]. To reach maximum height the dynamics such as impact, dynamic response, and torque production are dependent on shape, inertia and mass, which gives reason to assume an optimal shape exists. This leads to the research question: What are the optimal geometric and inertial parameters of a skateboard for an Olympic athlete to reach maximal ollie height. The skateboard geometry is optimized through multiphase direct collocation with the objective of maximal ollie height. A parameterized model is created with scaling mass and inertia properties such that the geometry of the skateboard. Modelling the dynamics of the ollie including impact and friction are done with a point mass human controller that is kineticly and kinematicly mapped to a counter movement jump. A simplistic contact implicit impact scheme is made for a higher order optimization. The ollie height is improved by changing the mass and inertia properties of the skateboard. Multiple optimal board shapes are generated for example a skateboard with a smaller wheelbase can reach higher ollie height compared to an industry standard skateboard.https://github.com/mechmotum/ollie-optimization Github repository with code and data https://www.youtube.com/watch?v=jw5DmNnvD7c Video made of found optimization trajectoriesBiomedical Engineerin
New birth - Uldis (Ollie 1935-1994) Auzins
No full textBlack & White photo of birth of Ollie (Uldis). 1935-1994. Taken in Latvia.2.1.2 Current Latvian History and Culture (Pre-Post WWII), 4.1.3 Third Wave Immigrants (Post WWII), 10.1.2 Children's lives during the conflict
George and Ollie Auzins
No full textBlack & white photo of George and Ollie Auzins standing in front of Auzins family home in Edmonton, Alberta. Ollie in Edmonton City Police uniform8.0 Family Home in Alberta, 9.0 Life in Edmonton and Albert
Oh, glory, glory, glory, somebody touched me,
No full textvoiceCollected by Mary Shand Transcribed by M. C. Parler
Ollie Gilbert Mountain View, Ark. October 26, 1963
Reel 423, Item 14
Somebody Touched Me
While I was preaching, somebody touched me,
While I was preaching, somebody touched me,
While I was Preaching, somebody touched me.
It must have been the hand of the lord.
Oh, glory, glory, glory, somebody touched me,
Glory, glory, glory, somebody touched me,
Glory, glory, glory, somebody touched me,
It must have been the hand of the lord.
While I was praying, somebody touched me.
Repeats and refrain as above.
While I was singing, somebody touched me.
Repeats and refrain as above.Funding for digitization provided by the Arkansas Humanities Council and the Happy Hollow Foundation
When I was a bachelor bold and young, I courted a widow with a clattering tongue,
No full textvoiceCollected by Mary Shand Transcribed by M. C. Parler
Ollie Gilbert Mountain View, Ark. Oct. 26, 1963
Reel 423, Item 16
When I Was a Bachelor
When I was a bachelor bold and young,
I courted a widow with a clattering tongue,
The kisses that I give her was a hundred and ten,
I told her I'd marry, but I didn't tell her when.
Monday morning I married me a wife,
I hope I'll live a happy life
We fiddled and danced just all we pleased,
To think how happy we would be.
Teusday morning all alone,
Said an old wife scold and gone (?)
She ripped, she tore, she cursed, she swore,
The like I never heard before.
Wednesday morning I went to the woods Hoping that she'd prove good,
Cut me down a little willow green,
I believe it's as keen a one as ever I seen.
Thursday morning I whipped her well,
Whipped her more that tongue could tell,
Told her that she better not be
The Devil would take her, and take her for me.
Friday morn at the break of day,
There she lay as cold as clay
Roof and a proof and a little patch of cane,
The Devil took her off in a little shower of rain.Funding for digitization provided by the Arkansas Humanities Council and the Happy Hollow Foundation
Interview with Ollie Zipperer Fogarty
No full textMrs. Fogarty discusses her family history (Zipperer) and that of her husband's family. She was the author of the book "They Called It Fogartyville". Interview conducted by Libby Warner
Maximizing ollie height by optimizing control strategy and skateboard geometry using direct collocation
No full textThe ollie is the base aerial human–board maneuver, foundational to most modern skateboarding tricks. We formulate and solve an optimal control problem of a two-dimensional simplified human model and a rigid body skateboard with the objective of maximizing the height of the ollie. Our solution simultaneously discovers realistic human-applied force trajectories and optimal board geometry. We accomplish this with a direct collocation formulation using a null seed initial guess by carefully modeling the discontinuous aspects of board–ground impact and foot–board friction. This leads to efficient and robust solutions that are 10 times more computationally efficient than prior work on similar problems. The solutions show that ollie height can increase 3% by decreasing the wheelbase and that a smaller board with a back-foot-dominated force strategy can give 12% higher ollies. Our model can be used to inform jump strategy and the effects of changes to the essential board geometry.Biomechatronics & Human-Machine Contro
Valdis Auzins and son Ollie and modified 1929 Chevrolet truck
No full textBlack & white photo of Valdis Auzins and his son Ollie in their modified 1929 Chevrolet turck in front of their homestead home at Pigeon Lake, Alberta15.0 Family Photos, 15.1.3 Family life in Alberta, 5.0 Early Life of Latvians in Albert
Stewart, Ollie
Get PDFOllie Anderson Stewart (1906-1977), journalist, was the first African American war correspondent to go abroad during World War II. Notable among the correspondents from whom he solicited information was Mercer Cook, an author, professor of romance languages at Howard University, and later, ambassador to several African countries. Cook provided invaluable recollections of his associations with Baker. (His father, Will Marion Cook (1869-1944), was the famed violinist, composer and orchestral director.) The collection covers intermittent periods from 1953-1977, and was transferred to MSRC by a brother Dr. James W. Stewart in 1977-78
Ollie Auzins at Auzin's Ancestral Home and property in Latvia
No full textOllie Auzins standing in frotn of badly neglected Auzins ancestral family home and lands in Adazi District ( near Riga). Not long after the end of Soviet occupation of Latvia.8.0 Ancestral Family home and Land, 8.1.1 Family Home in Latvia,2.1.3 Current Latvian History in Europse ( Pre-Post WWII
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