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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Player perceptions and biomechanical responses to tennis court surfaces : the implications to technique and injury risk

Starbuck, Chelsea January 2014 (has links)
Elite tennis players are required to perform on a variety of tennis court surfaces which differ in mechanical characteristics, such as friction and hardness, influencing their performance and risk of injury. To understand the influence of surfaces on performance and injury risk, three studies were conducted to investigate tennis players' perceptions and biomechanical responses during tennis-specific movements on different court surfaces. In study 1, tennis players perceptions of acrylic and clay courts were identified following a thematic inductive analysis of semi-structured interviews (n = 7) to develop a series of visual analogue scales (VAS) to quantify perceptions during studies 2 and 3. Perceptions of predictability of the surface and players' ability to slide and change direction emerged, in addition to anticipated perceptions of grip and hardness. Study 2 aimed to examine the influence of court surfaces and prior clay court experience on perceptions and biomechanical characteristics of tennis-specific skills. Perception, kinematic, insole pressure and mechanical data were collected on an acrylic and a clay court. In agreement with findings reported in study 1, lower mechanical friction and hardness on the clay court were perceived and accompanied by less predictability and greater difficulty to change direction whilst being easier to slide. As result of sliding, players' adopted an altered technique on the clay court compared to the acrylic leading to reductions in loading provide evidence to explain lower injury risks previously reported on clay courts. Prior clay court experience did not influence players' perceptions. However, biomechanical response to the clay surface differed, such that players with high clay court experiences contacted the ground with an everted foot, believed to contribute to controlling sliding. Differences in perception-response relationships were reported between experience groups suggesting players with greater clay court experience are better able to choose an appropriate response to improve their performance. Friction properties of the surface may change during play on clay courts due to player movements and sliding on the court. Therefore there may be areas of expected and unexpected changes to friction to which players must respond to. Study 3 aimed to examine the influence of changes in friction and players awareness of these changes on perceptions and biomechanical response. Compared with study 1 and 2, players found it more difficult to identify differences in perceived grip during study 3, possibly due the smaller mechanical friction differences reported. Unexpected reductions in friction produced greater initial ankle inversion angles compared to the expected decreases in friction, increasing players' risk of injury. Lower horizontal and vertical loading rates were reported on the lower friction conditions where further sliding was reported; suggesting a reduced injury risk by allowing longer time spent applying the forces. This thesis has identified key perception variables that enabled a holistic understanding of perceptions and their interaction with biomechanical response. Mechanical friction was an important factor influencing players' ability to slide. Sliding on clay resulted in altered loading characteristics, pressure distributions and kinematics potentially reducing players' injury risk. Tennis players' experience of clay courts does not influence their perceptions of the surface but the response that players adopt, which lower their risk of injury and increase performance. It is important when playing on a clay court that friction properties are maintained across the court during a tennis match as much as possible to reduce injury risks, due to the influence of unexpected changes to friction on perceptions and response.
2

Precision Court Sweeper / Tennisborste

Alke, Jenny, Sandahl, Maria January 2021 (has links)
Tennis is a popular sport and in summer it’s often played outside. When an outdoors tennis court has been used it needs to be brushed. First the whole court is brushed witha large brush and then the white lines with a smaller brush. The aim of this thesis was to design and build a working prototype of a robot who can do all of this by itself i.e sweep the court and then the white lines. The budget for components to the prototype was limited to 1 000 SEK. Tools and other resources such as 3D-printers, soldering equipment and laser cutters was provided by KTH for free. First information and inspiration about self-driving cars and driving patterns was collected and some important sources were old bachelor’s thesis. Then, needed components and dimensions could be determined. In this project the main components were an Arduino Uno, two DC motors, an L298H-bridge, an ultra sonic distance sensor, an on/off switch, AAA batteries and a 9 V battery. The conclusions that could been drawn was that the robot can work good enough to sweep a court with only a preprogrammed path. However, to sweep the white lines, sensors would be necessary. It could also be concluded that a robot could sweep the court at the same speed as two people could do it. / Tennis är en populär sport och på sommaren spelas den ofta utomhus. När en utomhustennisbana har använts måste den borstas. Först borstas hela banan med en stor borste och sedan de vita linjerna med en mindre borste. Syftet med denna uppsats var att designa och bygga en fungerande prototyp av en robot som kan göra allt detta av sig själv dvs. sopa tennisbanan och sedan de vita linjerna. Budgeten för komponenter till prototypen var begränsad till 1000 SEK. Verktyg och andra resurser så som 3D-skrivare, lödutrustning och laserskärare tillhandahölls av KTH gratis. Det första som gjordes var att samla information och inspiration om självkörande bilar och olika körmönster och några viktiga källor var gamla kandidatexamensuppsatser. Sedan kunde nödvändiga komponenter och dimensioner bestämmas. I detta projekt var huvudkomponenterna en Arduino Uno, två DC-motorer, en L298 H-brygga, en ultraljudssensor, en på/av-omkopplare, AAA-batterier och ett 9 V batteri. Slutsatserna som kunde dras var att roboten kan fungera tillräckligt bra för att borsta en tennisbana med endast en förprogrammerad bana. För att sopa de vita linjerna skulle sensorer dock vara nödvändiga. En annan slutsats var att en robot kan sopa banan på samma tid som det krävs för två personer att sopa varsin halva.
3

Sportovní centrum / Sports center

Machač, Matěj January 2016 (has links)
The objective of this thesis is to create the documentation for building construction.Designed building is a sports center, which is used for playing tennis. The project is located in the cadastral Holostřevy, a small village near the town of Plzen. Construction will be visible from the highway D5, which is widely used by German, Austrian and Czech drivers and her attendance and payback will be more effectiv. And the architectural appearance shoud be also contribute. Project documentation has been prepared in compliance with applicable laws, regulations and standards. The building is functionally, operationally and structurally divided into two parts. The first part is called "zázemí" (background). It is the skeleton construction of reinforced concrete with cross reinforced the plate. Packing construction is only between the base and the ceiling and itsn't supporting. In the "zázemí" there are dressing rooms, sanitary facilities, but also a café. The second part is a "hala" (hall). It only serves to playing tennis. The supporting construction is a lamellar wood trusses and central column in "zázemí" supporting it. It is interesting that on the 2nd floor which serves as a grandstand, are formed two parts, one of which serves as an auditorium for interior court and the other as an auditorium for exterior court.

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