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Littérature scientifique sur le sujet « Dynamic warm-up with Thera-Band »

Auteur : Grafiati

Publié le 4 juin 2021

Mis à jour le 4 février 2022

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Articles de revues sur le sujet "Dynamic warm-up with Thera-Band"

Yoo, Inhwa, et Hyung-Min Yoon. « The Effect of Two Exercise Types in the 8 Week Exercise Training on the Physical Fitness of Elderly Women ». Asian Journal of Kinesiology 22, n^o 1 (31 janvier 2020) : 15–23. http://dx.doi.org/10.15758/ajk.2020.22.1.15.

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OBJECTIVES The purpose of this study was to investigate the effect of two exercise types (Gyrokinesis exercise and Elastic band exercise) in the 8 week exercise training on the physical fitness of elderly women.METHODS The subjects of this study were 57 elderly women between 65 and 80 years old, who had no abnormality in the Physical Readiness Questionnaire (PAR-Q test) and were able to do physical activity on the orthopedic standpoints. The subjects were divided into three groups: Gyrokinesis Exercise Group (GKEG: n=19), Elastic Band Exercise Group (EBEG: n=20), and Control Group (CG: n=18). The subjects performed a Gyrokinesis Exercise in GKEG and an Elastic Band Exercise in EBEG for 50 minutes a day (10 minutes for warm-up, 30 minutes for main exercise, 10 minutes for cool-down), and 3 times a week for a total of 8 weeks. The subjects of CG did not participate in any particular exercise program but only everyday life. The dependent variables were Physical Fitness: Upper Muscular Endurance, 30-Second Arm Curl. Lower Flexibility, Dynamic Balance, Endurance. one-way ANOVA with repeated measurements was used to test the hypothesis in this study. A post hoc was conducted only when there was an interaction effect between groups and measurements. The difference of the post-test between groups were analyzed through Scheffe method after one-way ANOVA. The statistical significance level of this study was α=.05.RESULTS Gyrokinesis and Elastic Band Exercises were both effective on the physical fitness of elderly women: Upper Muscular Endurance, 30-Second Arm Curl, Lower Flexibility, Dynamic Balance, and Endurance. However, there were no differences in exercise effects after 8 week exercise training between the Gyrokinesis Exercise Group and the Elastic Band Exercise Group.CONCLUSIONS It is concluded that Gyrokinesis and Elastic Band exercise programs should be encouraged to improve physical fitness of elderly women and we need a follow-up study with longer term exercise training programs to find the differences in exercise effects between Gyrokinesis Exercise and Elastic Band Exercise.

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Nouri, Reza, Klaus Michaeil Braumann, Bahareh Mahmoudieh ChamPiri, Jan Schröder et Mahdieh Akochakian. « Cancer Related Fatigue and Upper Limb Disabilities Cannot Improve after 6 Weeks Resistance Training with Thera-Band in Breast Cancer Survivors ». International Journal of Applied Exercise Physiology 7, n^o 2 (17 juin 2018) : 76–84. http://dx.doi.org/10.22631/ijaep.v7i2.263.

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Aim. Breast cancer and its treatments lead to cancer related fatigue and upper limb disabilities. On the other hand, resistance training has positive benefits for breast cancer survivors. Thus, the aim of present study was to clarify the effect of resistance training with Thera – Band on CRF and upper limb disabilities in breast cancer survivors. Methods. Fifty women with breast cancer aged 29-65 were divided in to 2 groups: 1) resistance training with Thera- Band group (n=25) and 2) control group (n=25). Resistance training with Thera- Band group, after 5 minutes warm up, were performed the 9 resistance training with Thera – Band, from 8 to 12 repetitions and 2 sets in the first two weeks, 8 to 12 repetitions and 3 sets in the second two weeks and 8 to 12 repetitions and 4 sets in the third two weeks. The rest between each set was started from 90 seconds in the first week and was decreased to 45 seconds in the sixth week. Control group didn’t have any supervised or regular physical activity. Cancer related fatigue (CRF) and upper limb disabilities were surveyed by Piper Fatigue Scale and DASH questionnaire, respectively. Data were analyzed using by 2-way ANOVA (p≤0.05). Statistical Results. The findings of this study demonstrated that 6 weeks resistance training by Thera – Band has no significant effect on CRF and upper limb disabilities (p≥0.05). Conclusion. It can be concluded that exercise training with Thera- Band for 6 weeks cannot improve CRF and upper limb disabilities in breast cancer survivors. Future studies with large sample size and long period of intervention is suggested.

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Wu, Bing Hui, Bao Jun Pang et Zong Quan Deng. « Modeling and Simulation of Flexible Band Based on the Muti-Body Dynamics ». Key Engineering Materials 458 (décembre 2010) : 200–205. http://dx.doi.org/10.4028/www.scientific.net/kem.458.200.

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To provide theory and technique support for the research on dynamic properties of flexible lock-unlock technology, dynamic equation of band is built up based on the muti-body dynamics. Simulation based on modal neutral file and mixed model with rigid and flexible properties are accomplished in the software of ADAMS. The result reveals that the later one is much closed to the actual movement.

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Chen, Funan, Huili Bi, Soo-Hwang Ahn, Zhongyu Mao, Yongyao Luo et Zhengwei Wang. « Investigation on Dynamic Stresses of Pump-Turbine Runner during Start Up in Turbine Mode ». Processes 9, n^o 3 (10 mars 2021) : 499. http://dx.doi.org/10.3390/pr9030499.

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The startup process occurs frequently for pumped storage units. During this process, the rotating rate that changes rapidly and unsteady flow in runner cause the complex dynamic response of runner, sometimes even resonance. The sharp rise of stress and the large-amplitude dynamic stresses of runner will greatly shorten the fatigue life. Thus, the study of start-up process in turbine mode is critical to the safety operation. This paper introduced a method of coupling one dimensional (1D) pipeline calculation and three-dimensional computational dynamics (3D CFD) simulation to analyze transient unsteady flow in units and to obtain more accurate and reliable dynamic stresses results during start up process. According to the results, stress of the ring near fixed support increased quickly as rotating rate rose and became larger than at fillets of leading edge and band in the later stages of start-up. In addition, it was found that dynamic response can be caused by rotor stator interaction (RSI), but also could even be generated by the severe pressure fluctuation in clearance, which can also be a leading factor of dynamic stresses. This study will facilitate further estimation of dynamic stresses in complex flow and changing rotating rate cases, as well as fatigue analysis of runner during transient operation.

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Chen, Hong Mei, Hua Shun Yu, Guang Hui Min et Yun Xue Jin. « Study on the Microstructure and Texture of Warm Rolled ZK60 Magnesium Alloy Sheet ». Advanced Materials Research 557-559 (juillet 2012) : 1344–48. http://dx.doi.org/10.4028/www.scientific.net/amr.557-559.1344.

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The microstructure and macrotexture of ZK60 alloy sheet were investigated through OM and XRD, which were produced by twin roll casting and sequential warm rolling. Microstructure of twin roll cast ZK60 alloy changed from dendrite structure to fibrous structure with elongated grains and high density shear bands along the rolling direction after warm rolling process at different rolling parameters. The density of shear bands increased with the decreasing of the rolling temperature, or the increasing of per pass rolling reduction. Dynamic recrystallization could be found during the warm rolling process at and above 350oC, and many fine grains could be found in the shear band area. The warm rolled ZK60 alloy sheet exhibited strong (0001) basal pole texture. The formation of the shear bands tends to cause the basal pole tilt slightly to the transverse direction after warm rolling. The intensity of (0001) pole figure increased with the decreasing of rolling temperature, or the increasing of per pass rolling reduction.

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Sasaki, Hideharu, Bunmei Taguchi, Nobumasa Komori et Yukio Masumoto. « Influence of Local Dynamical Air–Sea Feedback Process on the Hawaiian Lee Countercurrent ». Journal of Climate 26, n^o 18 (9 septembre 2013) : 7267–79. http://dx.doi.org/10.1175/jcli-d-12-00586.1.

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Abstract Local air–sea interactions over the high sea surface temperature (SST) band along the Hawaiian Lee Countercurrent (HLCC) are examined with a focus on dynamical feedback of SST-induced wind stress to the ocean using the atmosphere–ocean coupled general circulation model (CGCM). A pair of ensemble CGCM simulations are compared to extract the air–sea interactions associated with HLCC: the control simulations and other simulations, the latter purposely eliminating influences of the high SST band on the sea surface flux computations in the CGCM. The comparison reveals that oceanic response to surface wind convergence and positive wind stress curl induced by the high SST band increases (decreases) the HLCC speed in the southern (northern) flank of the HLCC. The HLCC speed changes are driven by the Ekman suction associated with positive wind stress curl over the warm HLCC via the thermal wind balance. The HLCC speed increase is more significant than its decrease. This dynamical feedback is likely to be important to sustain the extension of the HLCC far to the west. The heat budget analysis confirms that advection of warm water from the west associated with this significant current speed increase plays a role in the southward shift of the HLCC axis. The dynamical feedback with the HLCC speed increase can potentially amplify the seasonal and interannual variations of HLCC.

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Battaglia, Alessandro, Pavlos Kollias, Ranvir Dhillon, Katia Lamer, Marat Khairoutdinov et Daniel Watters. « Mind the gap – Part 2 : Improving quantitative estimates of cloud and rain water path in oceanic warm rain using spaceborne radars ». Atmospheric Measurement Techniques 13, n^o 9 (15 septembre 2020) : 4865–83. http://dx.doi.org/10.5194/amt-13-4865-2020.

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Abstract. The intrinsic small spatial scales and low-reflectivity structure of oceanic warm precipitating clouds suggest that millimeter spaceborne radars are best suited to providing quantitative estimates of cloud and rain liquid water paths (LWPs). This assertion is based on their smaller horizontal footprint; high sensitivities; and a wide dynamic range of path-integrated attenuations associated with warm-rain cells across the millimeter wavelength spectrum, with diverse spectral responses to rain and cloud partitioning. State-of-the-art single-frequency radar profiling algorithms of warm rain seem to be inadequate because of their dependence on uncertain assumptions about the rain–cloud partitioning and because of the rain microphysics. Here, high-resolution cloud-resolving model simulations for the Rain in Cumulus over the Ocean field study and a spaceborne forward radar simulator are exploited to assess the potential of existing and future spaceborne radar systems for quantitative warm-rain microphysical retrievals. Specifically, the detrimental effects of nonuniform beam filling on estimates of path-integrated attenuation (PIA), the added value of brightness temperature (TB) derived adopting radiometric radar modes, and the performances of multifrequency PIA and/or TB combinations when retrieving liquid water paths partitioned into cloud (c-LWPs) and rain (r-LWPs) are assessed. Results show that (1) Ka- and W-band TB values add useful constraints and are effective at lower LWPs than the same-frequency PIAs; (2) matched-beam combined TB values and PIAs from single-frequency or multifrequency radars can significantly narrow down uncertainties in retrieved cloud and rain liquid water paths; and (3) the configuration including PIAs, TB values and near-surface reflectivities for the Ka-band–W-band pairs in our synthetic retrieval can achieve an RMSE of better than 30 % for c-LWPs and r-LWPs exceeding 100 g m−2.

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Fujii, Y., W. E. Tobler, E. M. Clausing, T. W. Megli et M. Haghgooie. « Application of dynamic band brake model for enhanced drivetrain simulation ». Proceedings of the Institution of Mechanical Engineers, Part D : Journal of Automobile Engineering 216, n^o 11 (1 novembre 2002) : 873–81. http://dx.doi.org/10.1243/095440702321031423.

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In a modern vehicle design process, analytical tools are widely employed to complement experimental approaches for design evaluation. When effectively utilized, they lead to a reduced development time with improved vehicle performance. The development process of an automatic transmission (AT) system can benefit from an analytical representation which accurately captures AT shifting behaviours. In a typical AT system, friction components such as wet clutches and band brakes are utilized to alter planetary gear configurations for automatic shifting. Thus, an accurate representation of friction component dynamics is critical in predicting AT shifting behaviour. Engagement characteristics of friction components vary widely under different operating conditions. Although the basic engagement physics was identified in the 1970s, it is relatively recently that a predictive, yet computationally efficient model became available. This paper describes the first attempt to utilize a dynamic friction component model in drivetrain simulations. Specifically, a dynamic band brake model is implemented to predict the up-shift behaviour of a four-speed AT system under various operating conditions. Simulation results are qualitatively validated with experimental data obtained from a dynamometer test stand. The dynamic band brake model enhances the shift predictability of a drivetrain model and potentially allows analytical evaluation of shift quality and control strategy.

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Vazza, F., S. Ettori, M. Roncarelli, M. Angelinelli, M. Brüggen et C. Gheller. « Detecting shocked intergalactic gas with X-ray and radio observations ». Astronomy & ; Astrophysics 627 (25 juin 2019) : A5. http://dx.doi.org/10.1051/0004-6361/201935439.

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Detecting the thermal and non-thermal emission from the shocked cosmic gas surrounding large-scale structures represents a challenge for observations, as well as a unique window into the physics of the warm-hot intergalactic medium. In this work, we present synthetic radio and X-ray surveys of large cosmological simulations in order to assess the chances of jointly detecting the cosmic web in both frequency ranges. We then propose best observing strategies tailored for existing (LOFAR, MWA, and XMM) or future instruments (SKA-LOW and SKA-MID, Athena, and eROSITA). We find that the most promising targets are the extreme peripheries of galaxy clusters in an early merging stage, where the merger causes the fast compression of warm-hot gas onto the virial region. By taking advantage of a detection in the radio band, future deep X-ray observations will probe this gas in emission, and help us to study plasma conditions in the dynamic warm-hot intergalactic medium with unprecedented detail.

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Wojtowicz, Sebastian, Anna Daniluk, Karolina Wiaderna, Aneta Bugalska, Anna Hadamus, Marta Grabowicz et Darius Bialoszewski. « ASSESSMENT OF IMPACT OF ACTIVATION OF HIP JOINT ABDUCTORS AND EXTERNAL ROTATORS ON GAIT AND RUNNNING PARAMETERS IN HEALTHY PEOPLE - PILOT STUDY ». Acta kinesiologica, N1 2021 (2021) : 120–26. http://dx.doi.org/10.51371/issn.1840-2976.2021.15.1.14.

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Many physiotherapists and motor preparation coaches recommend including resistance exercises for the hip joint abductors and external rotators in a warm-up. Muscle activation with resistance band exercises is believed to improve positional control of the pelvis and the lower limbs, thus reducing the risk of musculoskeletal injury during rehabilitation or training proper. The aim of this study was to assess the impact of a single session of activation of hip joint abductors and external rotators on gait and running parameters in healthy people. The study involved 54 healthy individuals aged 19-21 years. An experimental group (Group 1) performed a set of 6 resistance exercises with Thera rubber bands, intended to activate the hip joint abductors and external rotators. A control group (Group 2) performed the same set of exercises but without external resistance. A walking and running gait examination was performed on a Zebris FDM treadmill in both groups before and after the exercises. Both variants of exercises produced changes in selected gait parameters (p<0.05). An examination of running gait in Group 1 revealed an increase in step length in the dominant limb (p<0.05) and stride length (p<0.05) and step time in the dominant limb (p<0.05), stride length (p<0.05) and cadence (p<0.05). Heel pressure also decreased in both limbs, and heel pressure force decreased in the non-dominant limb (p<0.05). A running gait examination in Group 2 revealed increased midfoot pressure force in both limbs (p<0.05). Thus, a single session of exercises with resistance banding to activate the hip joint abductors and external rotators exerted an effect on running parameters, which may improve running economy.

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Thèses sur le sujet "Dynamic warm-up with Thera-Band"

Larsen, Christopher G. « Structural FRF Measurements up to 50 kHz to Assist Frequency Band Selection for Machinery Health Monitoring ». University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1337715377.

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Formánková, Dita. « Vliv dynamického a statického rozcvičení na svalovou sílu u lezců ». Master's thesis, 2015. http://www.nusl.cz/ntk/nusl-335390.

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Title Influence of dynamic and static warm-up on muscle strength in climbers. Objective The aim of the thesis is to assess the influence of dynamic warm-up with Thera-Band and static stretching on maximal muscle strength and its time parameters of finger flexors in dominant upper extremity in climbers. Methods Eight active climbers participated in this testing (age 32.4 ± 5.5, body weight 69.4 ± 6.5, height 176 ± 6.4). Actual performance RP was according to the French scale ranging 6b to 8a. Probands' measurements proceeded in three different days. After a specific warm-up on "boulder wall" and static stretching and dynamic warm-up with Thera-Band without stretching, there was maximal muscle strength of fingers flexors on dominant (preferred) upper limb measured by using a specific climbing test on hangboard. The second measurement assessed maximal strength of finger flexors muscle and its time parameters while proceeding of the maximum hand-grip using a hand dynamometer. Results In the experiment, none of the hypotheses came to be confirmed. There was no significant influence of static stretching and dynamic warm-up with Thera-Band on maximal muscle strength of finger flexors and the time parameters in climbers. Conclusion Despite the failure to prove the influence of the static stretching and...

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Actes de conférences sur le sujet "Dynamic warm-up with Thera-Band"

Peters, W. K., B. Cho, R. J. Hill, T. L. Courtney et D. M. Jonas. « Band Filling Dynamics and Auger Recombination in Lead Sulfide Nanocrystals ». Dans International Conference on Ultrafast Phenomena. Washington, D.C. : OSA, 2010. http://dx.doi.org/10.1364/up.2010.tue19.

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Weber, M., J. Song et J. G. Lee. « Characterization of Dynamics of Unstable Fuel-Rich Flame ». Dans ASME Turbo Expo 2021 : Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/gt2021-60121.

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Abstract The flame dynamics during unstable combustion occurring in a model gas turbine combustor under fuel-rich conditions analogous to idle and sub-idle conditions in an aero-engine is characterized by simultaneous measurement of flame emissions and dynamic pressure fluctuation as well as high-speed imaging. Pressure fluctuation during unstable combustion causes linearly increasing velocity fluctuation at the combustor inlet. The fluctuation level of CH*-band emission which is mainly from soot linearly increases with respect to the combustor inlet velocity fluctuation up to ∼40% of mean velocity while that of OH*-band emission which is from OH* is non-linear. Highspeed imaging shows that the OH*-band emission fluctuation occurs mainly near the dump plane but the CH*-band emission fluctuation occurs downstream of it. When the pressure fluctuation is more than 1% of mean pressure, there exists an almost constant phase delay between emissions from OH*- and CH*-band and dynamic pressure fluctuations and the phase delay satisfies the Rayleigh criterion. In addition, the Rayleigh integral made over the whole flame and one period of oscillation of thermoacoustic instability becomes positive. These may suggest either OH*- or CH*-band emission can be used as a representation of heat release. However, the observations that the mean OH*-band emission intensity increases but the mean CH*-band emission intensity does not as the mean equivalence ratio increases and the fluctuation level of emission in OH*-band increases but that in CH*-band emission does not as the pressure fluctuation level increases strongly suggest that the emission from OH*-band should be considered as a representation of heat release for sooty flames under the employed operating condition in this study.

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Takewaka, Satoshi. « Intertidal Morphology and Wave Run-Up Observations during a Storm Event with X-Band Nautical Radar ». Dans Fifth International Conference on Coastal Dynamics. Reston, VA : American Society of Civil Engineers, 2006. http://dx.doi.org/10.1061/40855(214)62.

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Hoffmann, Christian, et Peter Russer. « A broadband high-dynamic time-domain system for EMI measurements in K-Band up to 26 GHz ». Dans 2011 IEEE International Symposium on Electromagnetic Compatibility - EMC 2011. IEEE, 2011. http://dx.doi.org/10.1109/isemc.2011.6038361.

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Torres, David, Tongyu Wang, Jun Zhang, Sarah Dooley, Xiaobo Tan et Nelson Sepúlveda. « Experimental Characterization of the Dynamics of VO2-Based MEMS Mirrors ». Dans ASME 2016 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/smasis2016-9129.

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In this work, the time and frequency response of VO2-based MEMS mirrors are characterized across the transition for individual and simultaneous actuation. First, a step input train of increasing amplitude are applied to the device up to the point of transition is reached. Second, the frequency response is measured by applying a small sinusoidal input, where the displacement remained inside the hysteresis of the VO2. The frequency of the input varied from 0.1 to 2000 Hz. The thermal dynamics of the device is found to be the factor limiting the device’s band-width to less than 10 Hz. The average resonant frequency of the present VO2-based MEMS mirror was found to be 412.5 Hz for individual actuation. These results allow for the extraction of the necessary parameters to create a model that can be used to design devices with specific dynamic performance.

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Liao, Yi-Wen, et J. Karl Hedrick. « A Discrete-Time Integral Sliding Model Predictive Control for Obstacle Avoidance of Ground Vehicles ». Dans ASME 2015 Dynamic Systems and Control Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/dscc2015-9741.

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In this paper, a robust control architecture is proposed for lane-keeping and obstacle avoidance of autonomous ground vehicles. A two-level hierarchical controller is used to separate the planning and tracking problems. At the higher-level, we solve a nonlinear model predictive control (MPC) problem with an oversimplified point-mass model. The desired trajectories are generated and fed into the lower-level controller, where a force-input nonlinear bicycle model is considered to set up the tracking control law. Moreover, at each time step, a linearized bicycle model is derived and implemented to reduce the real-time computational complexity. Based on the above profile, a discrete-time integral sliding MPC (DISMPC) technique is used to improve the system robustness. By introducing an additional sliding control term into the feedback control law, the system trajectories can be maintained within a quasi-sliding band. In this case, it becomes necessary to take into account the system dynamics induced by the sliding control. Namely, the state and the input constraints of the MPC problem at each level need to be tightened. This helps to guarantee the feasibility of the original constrained problem in the presence of disturbances. Simulations have been carried out to verify the effectiveness of the proposed controller. The results show that the controller is able to simultaneously achieve lane-keeping and obstacle avoidance with uncertain friction coefficients.

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Gentemann, A., C. Hirsch, K. Kunze, F. Kiesewetter, T. Sattelmayer et W. Polifke. « Validation of Flame Transfer Function Reconstruction for Perfectly Premixed Swirl Flames ». Dans ASME Turbo Expo 2004 : Power for Land, Sea, and Air. ASMEDC, 2004. http://dx.doi.org/10.1115/gt2004-53776.

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The introduction of lean premix combustion increases the susceptibility of the combustor to thermoacoustic instabilities. To control these instabilities, information about the dynamic behavior of the combustion process is necessary. The flame transfer function offers one possibility to describe the dynamic behavior of the combustion process. It relates velocity fluctuations through the burner to an overall heat release fluctuation caused by the flame. As the transfer function for turbulent premix swirl flames can not be derived accurately from first principles, an alternative approach is needed. This paper introduces and validates a method, based on computational fluid dynamics (CFD), to reconstruct flame transfer functions. A transient simulation of the turbulent reacting flow is performed with broad band excitation of the flow variables on the boundaries. On the basis of the resulting time series for velocity and heat release, the transfer function of the flame is reconstructed by application of a system identification procedure based on the Wiener-Hopf equation. This method is applied to a lean perfectly premixed swirl burner. The resulting transfer function is validated with experimental data up to frequencies of f = 400 Hz. Good qualitative agreement is observed between the two approaches. Remarkably, the absolute value of the flame transfer function (the ‘gain’ of the flame) is found to be larger than unity over a range of frequencies, even though fluctuations of heat release and velocity are normalized with their mean flow values. To gain insight into this phenomenon, the dynamic behavior of the flame is investigated in detail. This concerns in particular the interaction of velocity, heat release fluctuations, the swirl number, and fluctuations of flame position and shape. Instead of broad band excitation, single frequency excitation is applied on the boundary for these investigations. It is found that swirl number fluctuations are convected into the flame. At the frequency where the wavelength of those fluctuations agrees with the length scale of the flame, unburned gases accumulate in the combustor. The excess heat is released periodically, which causes the overshoot in the absolute value of the flame transfer function.

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Luo, Feng, et Dongsheng Ma. « Integrated adaptive step-up/down switching DCDC converter with tri-band tri-mode digital control for dynamic voltage scaling ». Dans 2008 IEEE International Symposium on Industrial Electronics (ISIE 2008). IEEE, 2008. http://dx.doi.org/10.1109/isie.2008.4677168.

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Blotenberg, Wilfried. « A Model for the Dynamic Simulation of a Two-Shaft Industrial Gas Turbine With Dry Low NOx Combustor ». Dans ASME 1993 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1993. http://dx.doi.org/10.1115/93-gt-355.

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A dynamic simulation model for a twin-shaft industrial gas turbine is presented. The model is of modular design. Each component is modelled individually. This allows the model user to modify selected items without having to remodel the complete system. The model allows the simulation of a complete operation cycle from start-up via part load, full load operation and load drop. Simulation results of 14 selected operating points have been compared with measured values from trial test runs. 65 % of the calculated values do not deviate more than 2 % from the referenced values, and over 90 % of all simulated values are located in a tolerance band of less than 5 %. The dynamic response of the model is demonstrated by comparing the measured speed response during a load shedding test with the respective simulation result.

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Szwedowicz, J., C. Gibert, T. P. Sommer et R. Kellerer. « Numerical and Experimental Damping Assessment of a Thin-Walled Friction Damper in the Rotating Set-Up With High Pressure Turbine Blades ». Dans ASME Turbo Expo 2006 : Power for Land, Sea, and Air. ASMEDC, 2006. http://dx.doi.org/10.1115/gt2006-90951.

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Under-platform friction dampers are preferably solutions for minimizing vibrations of rotating turbine blades. Solid dampers, characterized by their compact dimensions, are frequently used in real applications and often appear in patents in different forms. A different type of the friction damper is a thin-walled structure, which has larger dimensions and smaller contact stresses on a wider contact area in relation to the solid damper. The damping performance of a thin-walled damper, mounted under the platforms of two rotating, freestanding high pressure turbine blades is investigated numerically and experimentally in this paper. The tangential and normal contact stiffness, that are crucial parameters in optimal design of each friction damper, are determined from three-dimensional finite element (FE) computations of the contact behaviour of the thin-walled damper on the platform including friction and centrifugal effects. The computed contact stiffness values are applied to non-linear dynamic simulations of the analysed blades with the friction damper of a specified mass. These numerical analyses are performed in the modal frequency domain with a code, which is based on the Harmonic Balance Method (HBM) for the complex linearisation of friction forces. The blade vibrations are characterised by a set of the lowest FE mode shapes of one freestanding blade without damper. The dynamic results of the calculated blades with the damper are in good agreement with the measured data of the real mistuned system. In the analysed excitation range, the numerical performance curve of the thin-walled damper is obtained within the scatter band of the experimental results. For the known friction coefficients and available FE and HBM tools, the described numerical process confirms its usability in the design of under-platform dampers.

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