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An Investigation into the Relationship between Maximum Isometric Strength and Vertical Jump PerformanceThomas, Christopher, Jones, Paul A., Rothwell, James, Chiang, Chieh Y., Comfort, Paul 01 January 2015 (has links)
Research has demonstrated a clear relationship between dynamic strength and vertical jump (VJ) performance; however, the relationship of isometric strength and VJ performance has been studied less extensively. The aim of this study was to determine the relationship between isometric strength and performance during the squat jump (SJ) and countermovement jump (CMJ). Twenty-two male collegiate athletes (mean ± SD; age 21.3 ± 2.9 years; height 175.63 ± 8.23 cm; body mass 78.06 ± 10.77 kg) performed isometric midthigh pulls (IMTPs) to assess isometric peak force (IPF), maximum rate of force development, and impulse (IMP) (I100, I200, and I300). Force-time data, collected during the VJs, were used to calculate peak velocity, peak force (PF), peak power (PP), and jump height. Absolute IMTP measures of IMP showed the strongest correlations with VJ PF (r 0.43-0.64; p ≤ 0.05) and VJ PP (r 0.38-0.60; p ≤ 0.05). No statistical difference was observed in CMJ height (0.33 ± 0.05 m vs. 0.36 ± 0.05 m; p 0.19; ES-0.29) and SJ height performance (0.29 ± 0.06 m vs. 0.33 ± 0.05 m; p 0.14; ES-0.34) when comparing stronger to weaker athletes. The results of this study illustrate that absolute IPF and IMP are related to VJ PF and PP but not VJ height. Because stronger athletes did not jump higher than weaker athletes, dynamic strength tests may be more practical methods of assessing the relationships between relative strength levels and dynamic performance in collegiate athletes.
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A dynamic slack management technique for real-time distributed embedded systemsAcharya, Subrata 12 April 2006 (has links)
This work presents a novel slack management technique, the Service Rate Based Slack Distribution Technique, for dynamic real-time distributed embedded systems targeting the reduction and management of energy consumption. Energy minimization is critical for devices such as laptop computers, PCS telephones, PDAs and other mobile and embedded computing systems simply because it leads to extended battery lifetime. Such systems being power hungry rely greatly upon the system design and algorithms for processing, slack and power management. This work presents an effcient dynamic slack management scheme for an energy aware design of such systems. The proposed Service Rate Based Slack Distribution Technique has been considered with two static(FCFS, WRR) and two dynamic(EDF, RBS) scheduling schemes used most commonly in distributed systems. A fault tolerance mechanism has also been incorporated into the proposed technique inorder to use the available dynamic slack to maintain checkpoints and provide for rollbacks on faults. Results show that in comparion to contemporary techniques, the proposed Service Rate Based Slack Distribution Technique provides for about 29% more perfor-mance/overhead savings when validated with real world and random benchmarks.
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Analysis of a Retrofitted Thermal Energy Storage Air-conditioning System of a Marine MuseumYu, Po-wen 31 May 2005 (has links)
Thermal energy storage(TES) air-conditioning system is a electrical load management technology with great potential to shift load from peak to off-peak utility periods. TES is now in widespread use for electric rate structures and energy policies and becomes a great contribution to energy conservation. However, TES is more complicated than conventional air-conditioning system in design and control strategies. According to practical field operation, the control of dynamic characters is especially difficult, and so are storage capacity design , discharging rate and charging capacity selection.
This study set an example how to improve the energy performance of a retrofitted thermal energy storage air-conditioning system of a marine museum. Through full-scale experiment, historical air-conditioning operation data and computer simulation, the solution is provided on condition of unchanging major water pipe and equipment. This example can be a good demonstration for upping performance of TES. After testing and recording data for one year, this case indicates the investigation is effective and valuable to electric power management and green technology.
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A dynamic slack management technique for real-time distributed embedded systemsAcharya, Subrata 12 April 2006 (has links)
This work presents a novel slack management technique, the Service Rate Based Slack Distribution Technique, for dynamic real-time distributed embedded systems targeting the reduction and management of energy consumption. Energy minimization is critical for devices such as laptop computers, PCS telephones, PDAs and other mobile and embedded computing systems simply because it leads to extended battery lifetime. Such systems being power hungry rely greatly upon the system design and algorithms for processing, slack and power management. This work presents an effcient dynamic slack management scheme for an energy aware design of such systems. The proposed Service Rate Based Slack Distribution Technique has been considered with two static(FCFS, WRR) and two dynamic(EDF, RBS) scheduling schemes used most commonly in distributed systems. A fault tolerance mechanism has also been incorporated into the proposed technique inorder to use the available dynamic slack to maintain checkpoints and provide for rollbacks on faults. Results show that in comparion to contemporary techniques, the proposed Service Rate Based Slack Distribution Technique provides for about 29% more perfor-mance/overhead savings when validated with real world and random benchmarks.
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The Effect of Normobaric Hypoxia on Power Output During Multiple Wingate Anaerobic TestsNielsen, Corey Michael 05 May 2017 (has links)
No description available.
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Comparison of External Kinetic and Kinematic Variables between High Barbell Back Squats and Low Barbell Back Squats across a Range of LoadsGoodin, Jacob 01 August 2015 (has links)
This study compared peak force, peak power, peak velocity, impulse, work, and vertical displacement between the high bar back squat (HBBS) and low bar back squat (LBBS). Six trained males performed each using 20, 30, 40, 50, 60, 70, 80, and 90% of their recent training 1 repetition maximum. Dual force plates recorded force-time curve characteristics of ground reaction forces and four potentiometers tracked vertical and horizontal barbell displacement. Repeated–measures analysis of variance revealed a significant main effect for load (p<0.01) across all variables, but no significant effects for condition or interaction. The HBBS generated higher peak force in loads 20%–80%, higher peak power in loads 20%–60% and 80%–90%, higher peak velocity at every load, and greater vertical displacement at every load. The LBBS generated a larger impulse at loads 30%-90% and the HBBS generated more work at loads 20%, 40%, and 60%–90%.
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The Influence of Load and Inter-Repetition Rest on Force, Power, and Velocity in Multiple Sets of Hang Power CleansSwisher, Anna 01 August 2016 (has links)
The purpose of this dissertation was to determine the effects of several loads and multiple inter-repetition rest (IRR) intervals on peak power, peak velocity, and peak force in multiple sets of hang power cleans. Additionally, this dissertation investigates the load at which power and barbell velocity are maximized in a hang power clean, which is an area of the literature that requires greater clarity. From a practical perspective it is exceedingly difficult to make training recommendations to maximize power development or prescribe load and IRR intervals in cluster loading based on the current literature. The primary findings of this dissertation are 1) 70% 1RM maximizes power and velocity as compared to 80% 1RM in multiple sets of the hang power clean, 2) 45 seconds IRR improved peak velocity and peak power relative to a traditional set configuration, and 3) peak power output at 80% 1RM with 45 seconds IRR is equivalent to power output at 70% 1RM using a traditional set configuration. To the authors’ knowledge this is only the second study to examine the effect of IRR on multiple sets of power cleans in trained participants, and the insights from this dissertation help to build a foundation for future investigations in cluster loading with weightlifting movements. The findings from this dissertation provide further evidence for the efficacy of cluster loading as a training tool to develop power in trained individuals.
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Any Effect of Gymnastics Training on Upper-Body and Lower-Body Aerobic and Power Components in National and International Male Gymnast?Jemni, Monem, Sands, William A., Friemel, Françoise, Stone, Michael H., Cooke, Carlton B. 01 November 2006 (has links)
Aerobic and anaerobic performance of the upper body (UB) and lower body (LB) were assessed by arm cranking and treadmill tests respectively in a comparison of national (N) and international (I) male gymnasts. Force velocity and Wingate tests were performed using cycle ergometers for both arms and legs. In spite of a significant difference in training volume (4–12 vs. 27–34 h·wk−1 for N and I, respectively), there was no significant difference between N and I in aerobic and anaerobic performance. Upper body and LB maximal oxygen uptake (JOURNAL/jscr/04.02/00124278-200611000-00029/ENTITY_OV0312/v/2017-07-20T235327Z/r/image-pngO2max) values were 34.44 ± 4.62 and 48.64 ± 4.63 ml·kg−1·min−1 vs. 33.39 ± 4.77 and 49.49 ± 5.47 ml·kg−1·min−1, respectively, for N and I. Both N and I had a high lactic threshold (LT), at 76 and 82% of JOURNAL/jscr/04.02/00124278-200611000-00029/ENTITY_OV0312/v/2017-07-20T235327Z/r/image-pngO2max, respectively. Values for UB and LB force velocity (9.75 ± 1.12 and 15.07 ± 4.25 vs. 10.63 ± 0.95 and 15.87 ± 1.25 W·kg−1) and Wingate power output (10.43 ± 0.74 and 10.98 ± 3.06 vs. 9.58 ± 0.60 and 13.46 ± 1.34 W·kg−1) were also consistent for N and I. These findings confirm the consistency of JOURNAL/jscr/04.02/00124278-200611000-00029/ENTITY_OV0312/v/2017-07-20T235327Z/r/image-pngO2max values presented for gymnasts in the last 4 decades, together with an increase in peak power values. Consistent values for aerobic and anaerobic performance suggest that the significant difference in training volume is related to other aspects of perfomance that distinguish N from I gymnasts. Modern gymnastics training at N and I levels is characterized by a focus on relative strength and peak power. In the present study, the high LT is a reflection of the importance of strength training, which is consistent with research for sports such as wrestling.
Aerobic and anaerobic performance of the upper body (UB) and lower body (LB) were assessed by arm cranking and treadmill tests respectively in a comparison of national (N) and international (I) male gymnasts. Force velocity and Wingate tests were performed using cycle ergometers for both arms and legs. In spite of a significant difference in training volume (4–12 vs. 27–34 h·wk−1 for N and I, respectively), there was no significant difference between N and I in aerobic and anaerobic performance. Upper body and LB maximal oxygen uptake (JOURNAL/jscr/04.02/00124278-200611000-00029/ENTITY_OV0312/v/2017-07-20T235327Z/r/image-pngO2max) values were 34.44 ± 4.62 and 48.64 ± 4.63 ml·kg−1·min−1 vs. 33.39 ± 4.77 and 49.49 ± 5.47 ml·kg−1·min−1, respectively, for N and I. Both N and I had a high lactic threshold (LT), at 76 and 82% of JOURNAL/jscr/04.02/00124278-200611000-00029/ENTITY_OV0312/v/2017-07-20T235327Z/r/image-pngO2max, respectively. Values for UB and LB force velocity (9.75 ± 1.12 and 15.07 ± 4.25 vs. 10.63 ± 0.95 and 15.87 ± 1.25 W·kg−1) and Wingate power output (10.43 ± 0.74 and 10.98 ± 3.06 vs. 9.58 ± 0.60 and 13.46 ± 1.34 W·kg−1) were also consistent for N and I. These findings confirm the consistency of JOURNAL/jscr/04.02/00124278-200611000-00029/ENTITY_OV0312/v/2017-07-20T235327Z/r/image-pngO2max values presented for gymnasts in the last 4 decades, together with an increase in peak power values. Consistent values for aerobic and anaerobic performance suggest that the significant difference in training volume is related to other aspects of perfomance that distinguish N from I gymnasts. Modern gymnastics training at N and I levels is characterized by a focus on relative strength and peak power. In the present study, the high LT is a reflection of the importance of strength training, which is consistent with research for sports such as wrestling.
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Development and Characterization of a Regeneratively Amplified Ultrafast Laser System with an All-Glass Stretcher and CompressorWalker, Stephen January 2006 (has links)
High-peak power laser systems are defined along with a brief introduction of the technology used in their development and application to the project. A review of concepts surrounding optical pulses, focusing on the particular phenomena involved with the ultrafast, follows. Numerical models involving optical pulses are introduced and verified. An extensive description of the laser system is presented, including models used in its design. Data verifying the correct operation of the laser system is presented and interpreted. A dispersion compensation system, including a function model, is introduced, and its application to the laser system is analyzed. An introduction to pulse characterization techniques is presented followed by the design and verification of two different characterization devices. Experiments utlizing the dispersion compensation system and pulse characterization devices are presented and the results are interpreted. Conclusions are made regarding the performance of the laser system models and pulse characterization devices, along with suggested improvements for each. The results of the experiments are discussed including suggestions for future work.
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Development and Characterization of a Regeneratively Amplified Ultrafast Laser System with an All-Glass Stretcher and CompressorWalker, Stephen January 2006 (has links)
High-peak power laser systems are defined along with a brief introduction of the technology used in their development and application to the project. A review of concepts surrounding optical pulses, focusing on the particular phenomena involved with the ultrafast, follows. Numerical models involving optical pulses are introduced and verified. An extensive description of the laser system is presented, including models used in its design. Data verifying the correct operation of the laser system is presented and interpreted. A dispersion compensation system, including a function model, is introduced, and its application to the laser system is analyzed. An introduction to pulse characterization techniques is presented followed by the design and verification of two different characterization devices. Experiments utlizing the dispersion compensation system and pulse characterization devices are presented and the results are interpreted. Conclusions are made regarding the performance of the laser system models and pulse characterization devices, along with suggested improvements for each. The results of the experiments are discussed including suggestions for future work.
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