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A kinetic and kinematic comparison of the grab and track starts in competitive swimmingJuergens, Cheryl A. 24 October 1994 (has links)
In competitive swimming a spread in time of only 0.10,
and 0.16 seconds constituted the difference between
finishing second and seventh, and first and eighth,
respectively, in the women's 50 yard freestyle at the 1993
NCAA Division III National Swimming & Diving Championships.
Based on data collected over a period of years Maglischo
(1993) noted that "improving the start can reduce race times
by at least 0.10 second" (p. 544). Therefore it is
beneficial to the outcome of a race to direct attention to
maximizing the effectiveness of the racing start. The
primary purpose of this study therefore was to compare
kinetic and kinematic components of the grab and track style
starts.
During the past two decades extensive kinematic
research has been done using cinematography. These studies
used time, velocity, displacement, and the measure of angles
(i.e. at takeoff and entry) to measure the relative
effectiveness of various racing starts. Conversely, there
has been limited analysis of racing starts using kinetic
measurements.
Four kinetic and five kinematic variables were
evaluated in this study to compare the relative effectiveness
of the starting techniques. Ten female varsity
swimmers, who had used both starts interchangeably in
competition, were selected for this study. Force components
were obtained directly from a Kistler force platform. Block
time, horizontal and vertical impulse, and average horizontal
and vertical force values were obtained in subsequent
analysis of the Force-time data. Each subject was videotaped
as she executed three trials of each start. The video
data were digitized and then analyzed using two dimensional
video analysis techniques.
The type of start technique used on each trial was
randomly ordered. Kinematic variables of horizontal and
vertical displacement of the center of mass, average
horizontal velocity and vertical velocity were also obtained
from the video data in order to determine which of the two
starting techniques (i.e. grab vs. track) was the most
effective.
2x10 (starting technique x subject) repeated measures
Analyses of Variance indicated significant differences
(p<0.01) between the starting styles for five of the nine
dependent variables measured which provided support for the
original contention that the track style start was the more
effective of the two racing start techniques investigated.
The results of this study provide support to the empirical
and observational findings of earlier researchers. / Graduation date: 1995
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Massive binary stars and the kinematics of Young Massive ClustersHenault-Brunet, Vincent January 2013 (has links)
Located in the Large Magellanic Cloud, R136 is a rare example of a nearby young and dense massive star cluster in which individual stars can be resolved. Often suggested as a globular cluster in formation, its study is of great interest and promises to provide insights into the early dynamical evolution of massive star clusters. This is crucial to understand more extreme and distant starburst clusters, which contribute to a significant fraction of all current star formation in the Local Universe, in particular in interacting galaxies. The majority of this thesis is based on multi-epoch spectroscopic observations in and around R136 obtained as part of the VLT-FLAMES Tarantula Survey (VFTS), an ambitious programme which targeted nearly 1 000 massive stars in the intricate 30 Doradus star-forming region. The motivations and observing strategy of this survey, designed to address key questions about the evolution of massive stars and clusters, are first introduced. The data reduction procedures applied to VFTS data are described, with an emphasis on the tasks accomplished in the context of this thesis. The VFTS data are first used to perform a detailed kinematic study of R136, determine its dynamical state, and evaluate the importance of gas expulsion in the early evolution of massive star clusters. Orbital motions of binary stars are found to dominate the line- of-sight velocity dispersion of the cluster, illustrating the risk of interpreting velocity dispersion measurements for unresolved extragalactic young massive clusters. However, once the detected binaries are rejected and the contribution of undetected binaries is accounted for through Monte Carlo simulations, the true velocity dispersion of the cluster is found to be low and consistent with it being in virial equilibrium. This suggests that gas expulsion has not had a dramatic effect on the early dynamical evolution of R136. Using the velocity measurements of R136 as a test case, a maximum likelihood method that fits the velocity dispersion of a cluster from a single epoch of radial velocity data is then tested. The method must be applied with care given the high binary fraction of massive stars and the large uncertainties in their binary orbital parameter distributions, but for typical velocity dispersions of young massive clusters (& 4 kms−1), it is shown that the velocity dispersion can be measured with an accuracy of 40% or better. This offers an efficient way of constraining the dynamics of these systems. The radial velocity measurements of apparently single stars in R136 are also used to investigate the internal rotation of the cluster, a potentially important but largely unexplored characteristic of young clusters. Evidence is found, at the 95% confidence level, for rotation of the cluster as a whole. A simple maximum likelihood method is presented to fit rotation curves to the data, from which a typical rotational velocity of 3 kms−1 is found. When compared to the low velocity dispersion of R136, this suggests that star clusters may form with as much as 20% of their kinetic energy in rotation. Finally, a smaller-scale survey of massive stars in the Wing of the Small Magellanic Cloud is introduced. As an example of the particularly interesting massive binaries that can be revealed by the synergy between large optical spectroscopic surveys of young clusters and observations at other wavelengths, the discovery of a new Be/X-ray pulsar binary and associated supernova remnant is reported. With a long spin period of over 1 000 seconds and a young age of 104 years constrained by its association with the supernova remnant, the pulsar in this system is quickly emerging as a unique object that challenges our understanding of the spin evolution of accreting neutron stars.
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Optimizing freestyle flip-turn techniquePatz, Amy E January 2005 (has links)
Thesis (M.S.)--University of Hawaii at Manoa, 2005. / Includes bibliographical references (leaves 48-49). / vi, 49 leaves, bound ill. 29 cm
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Underwater kicking following the freestyle tumble-turnClothier, Peter January 2004 (has links)
Swim turns are a component of competitive swimming where considerable advantage can be gained or lost. This thesis investigates underwater dolphin and flutter kicking techniques and their application to exits following the turn in freestyle swimming. Five separate investigations were conducted to examine the kinetics and kinematics of each underwater kicking technique and are presented in expanded journal manuscript form. Studies one, two and three involved the comparison of freestyle turns when using flutter and dolphin kicking wall exit techniques. The results obtained indicated that freestyle turns using flutter kicking were faster than dolphin kicking in age-group swimmers. For this group, significant and equal improvements were made to flutter and dolphin kick turn performances following six weeks of dolphin kick and dolphin kick turn training. However, no difference in turn times were observed between kicking conditions by older and more highly skilled swimmers. Study four involved a kinematical comparison of maximal underwater free-swimming dolphin and flutter kicking. Results showed dolphin kick to be a superior underwater free-swimming technique. Greater foot width, increased ankle range of movement and greater vertical displacement of the ankle and foot during kicking were shown to be highly predictive of faster underwater dolphin kicking. Investigation five compared the drag forces and kinematics between the dolphin and flutter kicking techniques while subjects were towed at velocities representing those experienced following wall turn push-off. Results favour the dolphin kick as a superior underwater technique at these higher velocities. Increased underwater dolphin kicking efficiency, as measured by decreased net towing force, was found to be associated with larger kick amplitude – rate ratios, and higher kick amplitude – streamline length ratios. / Doctor of Philosophy
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Underwater kicking following the freestyle tumble-turnClothier, Peter . University of Ballarat. January 2004 (has links)
Swim turns are a component of competitive swimming where considerable advantage can be gained or lost. This thesis investigates underwater dolphin and flutter kicking techniques and their application to exits following the turn in freestyle swimming. Five separate investigations were conducted to examine the kinetics and kinematics of each underwater kicking technique and are presented in expanded journal manuscript form. Studies one, two and three involved the comparison of freestyle turns when using flutter and dolphin kicking wall exit techniques. The results obtained indicated that freestyle turns using flutter kicking were faster than dolphin kicking in age-group swimmers. For this group, significant and equal improvements were made to flutter and dolphin kick turn performances following six weeks of dolphin kick and dolphin kick turn training. However, no difference in turn times were observed between kicking conditions by older and more highly skilled swimmers. Study four involved a kinematical comparison of maximal underwater free-swimming dolphin and flutter kicking. Results showed dolphin kick to be a superior underwater free-swimming technique. Greater foot width, increased ankle range of movement and greater vertical displacement of the ankle and foot during kicking were shown to be highly predictive of faster underwater dolphin kicking. Investigation five compared the drag forces and kinematics between the dolphin and flutter kicking techniques while subjects were towed at velocities representing those experienced following wall turn push-off. Results favour the dolphin kick as a superior underwater technique at these higher velocities. Increased underwater dolphin kicking efficiency, as measured by decreased net towing force, was found to be associated with larger kick amplitude – rate ratios, and higher kick amplitude – streamline length ratios. / Doctor of Philosophy
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Evaluating the Effects of the D.A.N.C.E Training System on Staff and Child RespondingMorales, Erendira 12 1900 (has links)
The purpose of this study was to evaluate and systematically replicate the effectiveness of the DANCE training for a staff member to be an effective change agent for the children in her care, while maintaining the organization's and family's values. The study was conducted in an organization that values and focuses on building rapport, avoids the use of coercive procedures, and teaches children in a caring and meaningful way. A multiple baseline across indoor and outdoor settings was used to evaluate the effects of the package. Results demonstrated that DANCE training was an effective procedure to teach a staff member how to increase teaching interactions. Harmonious engagement, instructional engagement and vocal approximations also increased while challenging behavior maintained at zero levels.
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Kinematic analysis of freestyle and backstroke flip-turns in competitive swimmingLindley, Steven L. January 2001 (has links)
The primary purpose of this study was to gain a better understanding of the turn interval and the factors that influence turn performance. A secondary purpose was to investigate the relationship between turn time, the components that influence turn time, and performance in competitive swimming. Fifty-eight swimmers (24 female, 34 male) from four NCAA Division I schools were videotaped in the 100 and 200 yd freestyle and backstroke events during three collegiate competitions. The freestyle was shown to be significantly different from the backstroke in race time, turn time, and time during the in phase of the turn for both genders in the 100 and 200 yard events. Significant positive correlations were found between turn time and race time across both genders and all four events. Inspecting the velocity curves of the turns allowed the key outphase variables to be defined. Turn time is an important determinant of race time in collegiate swimming. Using the dolphin kick technique during a turn causes large fluctuations in velocity during the active glide phase of the turn. / School of Physical Education
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Jorge Diaz Gutierrez : a transatlantic journeyAviles Ruiz, Carlos G. 01 January 2010 (has links)
In a small attempt to expand the knowledge of Latin American plays and the biographical information of Jorge Diaz Gutierrez (1930-2007), I present one of his first plays La vispera del deguello, also known by El genesis fue maNana (1967). This project will inspire and benefit scholars, future translators, the theater community, and literature students to obtain a new perspective on Latin-American theatre. La vispera del deguello deals with existentialism; we enter the world of three remaining human beings on the planet: Custodio, Hosanna, y la loca (the mad woman). The structure of this project includes: the playwright's biography with the focus on his style rooted in the European literary tradition- and my translation of the play. Translating vispera del deguello is just the beginning of this project: future plans include producing, designing, and publishing the play. My contribution will be beneficial for a transatlantic dialogue among disciplines such as theatre, modem languages, and social sciences, among others. This project will expand the knowledge of the style of Latin-American theatre and recognize one of the best Spanish playwrights of the 20th century, Jorge Diaz Gutierrez.
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Optimization of the competitive swimming track start based on lower limb asymmetryHardt, Julie E. January 2008 (has links)
The swimming track start is a complex motor skill that utilizes asymmetric lower limb action. The purpose of this study was to explore whether it could be optimized by applying the commonly accepted view that there are asymmetries in the function and behaviors of the lower limbs. Initially, the study aimed to examine the relationship between various measures of lower limb asymmetry and the swimmers' preferences for forward foot placement in the swimming track start. Participants underwent a 7 week training period whereby both the left foot forward (LFF) and the right foot forward (RFF) track starts were practiced. The philosophy behind this training protocol was to ensure that participants received equal practice with the preferred and non-preferred stance so that a dominant stance, if it existed, could emerge. Consequently, the relationships between the dominant track start stance and the lower limb asymmetry measures could be determined more accurately. Participants were male (N=11) and female (N=11) swimmers, aged 12-16 years, from the UWA-Uniswim National Age Squad. Kinetic and kinematic data were collected for the track start prior to and following the 7 week training intervention. The intervention was finished when a participant had completed approximately 14 dive sessions where both the LFF and RFF track starts were practiced. The performance criterion measure was time to 5 m. Despite significant differences in vertical force and velocity contributions following the intervention, time to 5 m did not improve for either the LFF or the RFF track start. Four different measures of lower limb asymmetry were collected, including footedness, the preferred track start stance, and the dominant take-off limb for the unilateral and bilateral counter-movement jump (CMJ). Sixteen of 22 participants displayed changes in their dominant track start stance. Eleven participants showed biases for one stance (6 for the LFF & 5 for the RFF), and 11 participants remained or became more symmetrical. Results indicated that the preferred track start stance was the only measure of asymmetry that was significantly related to track start performance (x2[2]= 6.71, p=.04 for pre-intervention & x2[2]=7.77, p=.02 for post-intervention). All other measures of lower limb asymmetry were shown to be unrelated to track start preference and performance. It was suggested that the 7 week training intervention did not provide a sufficient amount of time to see conclusive effects on 5 m time or to make conclusive comparisons between the dominant track start stance and measures of asymmetry. Since the preferred track start corresponded with better performance less than 50% of the time, it was suggested that swimmers and coaches experiment with different dive techniques to find the start which is most effective for them and spend more time on them during training.
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Swimming in four goldfish (Carassius auratus) morphotypes: understanding functional design and performance through artificial selectionLi, Jason 05 1900 (has links)
Although artificially selected goldfish exhibit swimming performance decrements, with the most derived morphotypes more affected, they can be utilized to explore functional design and movement pattern principles in aquatic vertebrates. Drag, steady swimming kinematics (tailbeat frequency, amplitude, stride length), energetics (standard and active metabolic rate), fast-start performance (average and maximum velocity and acceleration), stability in yaw and roll and propulsive muscle ultrastructural characteristics (mitochondrial volume density and spacing, myofibril diameter and capillary to fibre ratio in red and white muscle) were measured for four morphotypes: common, comet, fantail and eggfish, of comparable length (≈ 5 cm). A performance “pairing” (common and comet; fantail and eggfish) was a recurrent theme for most performance parameters. Vertebral numbers (30), segment lengths (≈ 0.85 mm) and standard metabolic rates (≈ 140 mg O2 kg-1 hr-1) are exceptions where values are the same. Fantail and eggfish drag and drag coefficients (referenced to frontally projected area ≈ 0.6 - 0.9) were higher (requiring more thrust at any given velocity) than those for the more streamlined common and comet (≈ 0.3 - 0.6; P < 0.05). This is reflected in kinematics; tailbeat frequency and stride length at any given velocity for the common and comet are lower and higher respectively than that of the fantail and eggfish (P < 0.05). Common and comet fatigue times are not significantly different from that of their ancestor, Crucian carp (P > 0.05), and are lower than those of the fantail and eggfish (P < 0.05). The cost of transport of the common and comet (≈ 0.6 mg O2 kg-1 m-1) is accurately predicted from the mass scaling relationship for fish (P > 0.05), but values for the fantail and eggfish (≈ 1.3 mg O2 kg-1 m-1) are not (P < 0.05). Eggfish steady swimming (dorsal fin absent) was characterized by rolling and yawing motions associated with significant energy losses. Common and comet fast-start performance (average velocity ≈ 0.45 m s-1, maximum velocity ≈ 1.2 m s-1, average acceleration ≈ 7.5 m s-2, maximum acceleration ≈ 35 m s-2) was similar to that of other locomotor generalists (e.g. trout). Eggfish maximum acceleration (≈ 5 m s-2) is poor due to the absence of inertial and lifting contributions to thrust from the dorsal fin and energy wasting rolling motions. Artificially selected fish can bear upon fitness related adaptations associated with form and movement, providing insights into the “performance envelope” of natural systems subject to ecological speciation.
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