Journal articles on the topic 'Swimmers'
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Ramugade, Manoj, Kishor Sapkale, Sapna Sonkurla, and Abrar Sayed. "Evaluation of prevalence of dental erosion in swimmers in the metropolitan city of India: A cross-sectional study." International Journal of Orofacial Research 7, no. 1 (July 1, 2023): 13–19. http://dx.doi.org/10.56501/intjorofacres.v7i1.776.
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Introduction: Development and research in medical sciences have increased the life expectancy of the masses resulting in the retention of more teeth in the oral cavity. This leads to the occurrence of various wasting diseases of teeth like attrition, abrasion, and erosion. Aim and Objectives: This study evaluates the prevalence of Dental Erosion (DE) and its severity among swimmers of chlorinated pool water in a metropolitan city in India. Material and Methods: In this study, 508 young and adult regular swimmers (including competitive swimmers) from various swimming pools were selected and examined clinically for the presence of DE. A structured questionnaire form was formulated to record the history of habitual swimming activity, diet, gastroesophageal reflux disease, history of intake of medications and acidic beverages, etc. for each swimmer. The data obtained were analysed and statistically evaluated. Result: Among 508 swimmer participants, 429 were males and 79 were females. Out of these 338 (66.54%), including 293 (57.67%) male and 45 (8.8%) female swimmers showed DE. The mean age of the swimmer was 33.64 years. The majority of swimmers showed Grade I (n=260, 76.92%) type severity followed by Grade II (n=73, 21.59%) and Grade III (n=5, 1.47%). 79 (15.55%) swimmers showed teeth sensitivity. The statistical test showed a positive correlation between the duration of swimming activity and the non-use of dental protective measures with the severity of DE (P<0.05). Conclusion: Swimmer’s erosion is mainly attributed to the acidic pH of pool water associated with chlorine amount and its severity depends upon the duration and period of swimming irrespective of the swimmer’s gender.
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Tanaka, Takahiro, Satoru Hashizume, Toshiyuki Kurihara, and Tadao Isaka. "The Large and Strong Vortex Around the Trunk and Behind the Swimmer is Associated with Great Performance in Underwater Undulatory Swimming." Journal of Human Kinetics 84, no. 1 (October 25, 2022): 64–73. http://dx.doi.org/10.2478/hukin-2022-0087.
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Abstract Swimmers can produce horizontal body velocity by generating and shedding vortices around their body during underwater undulatory swimming (UUS). It has been hypothesized that the horizontal shedding velocity, area and circulation of the vortex around the swimmer’s body are associated with UUS performance. The purpose of this study was to investigate whether the shedding velocity, area and circulation of vortices around swimmers’ bodies are correlated with the horizontal body velocity during UUS. Computational fluid dynamics (CFD) was conducted to obtain the vortex structure during UUS in nine male swimmers. Morphological and kinematic data of each subject were obtained and used to reconstruct the UUS movement on CFD. The horizontal velocity of the center of vorticity, the area and circulation of vortices around the ventral side of the trunk, dorsal side of shoulder and waist, and behind the swimmer were determined from the simulation results. Positive correlations were found between the vortex area and circulation around the ventral side of the trunk (area r = 0.938, p < 0.05; circulation r = 0.915, p < 0.05) and behind the swimmer (area r = 0.738, p < 0.05; circulation r = -0.680, p < 0.05), and the horizontal body velocity. The horizontal shedding velocity of the center of vorticity of the vortices around the swimmer’s body was not significantly correlated with the horizontal body velocity. These results suggest that the generation of a large and strong vortex around the trunk and behind the swimmer is associated with great UUS performance.
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Kenny, John, SarahJane Cullen, and Giles D. Warrington. "The “Ice-Mile”: Case Study of 2 Swimmers’ Selected Physiological Responses and Performance." International Journal of Sports Physiology and Performance 12, no. 5 (May 2017): 711–14. http://dx.doi.org/10.1123/ijspp.2016-0323.
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Purpose:“Ice-mile” swimming presents significant physiological challenges and potential safety issues, but few data are available. This study examined deep body temperature (BT), respiratory rate (RR), and swim performance in 2 swimmers completing an ice-mile swim of 1 mile (1600 m) in water less than 5°C.Methods:Two male cold-water-habituated swimmers completed a 1-mile lake swim in 3.9°C water. For comparative purposes, they completed an indoor 1-mile swim in 28.1°C water. The Equivital physiological monitoring system was used to record BT and RR before, during, and after each swim. Total time to complete the swims and 400-m splits were recorded.Results:One swimmer became hypothermic after 27 min while swimming, reaching BT of 33.7°C at swim’s end. On exiting the water the swimmers experienced large BT after-drops of –3.6°C and –2.4°C, reaching low points of 33.2°C and 31.3°C 38 and 23 min postswim, respectively. Respiratory rate and swim pace decreased over the course of the ice-mile swim for both swimmers. Swim pace for 1 swimmer declined sharply in the final 400-m lap of the ice mile when he was hypothermic. Both swimmers remained hypothermic 60 min postswim (34.2°C and 33.4°C).Conclusion:Ice-mile swimmers may become hypothermic while swimming, and the postswim BT after drop may expose them to dangerous levels of hypothermia. Pace and RR should be monitored as proxies for a swimmer’s physiological state. Postswim recovery should also be monitored for hypothermia for at least 1 h.
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Wu, Paul Pao-Yen, Toktam Babaei, Michael O’Shea, Kerrie Mengersen, Christopher Drovandi, Katie E. McGibbon, David B. Pyne, Lachlan J. G. Mitchell, and Mark A. Osborne. "Predicting performance in 4 x 200-m freestyle swimming relay events." PLOS ONE 16, no. 7 (July 15, 2021): e0254538. http://dx.doi.org/10.1371/journal.pone.0254538.
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Aim The aim was to predict and understand variations in swimmer performance between individual and relay events, and develop a predictive model for the 4x200-m swimming freestyle relay event to help inform team selection and strategy. Data and methods Race data for 716 relay finals (4 x 200-m freestyle) from 14 international competitions between 2010–2018 were analysed. Individual 200-m freestyle season best time for the same year was located for each swimmer. Linear regression and machine learning was applied to 4 x 200-m swimming freestyle relay events. Results Compared to the individual event, the lowest ranked swimmer in the team (-0.62 s, CI = [−0.94, −0.30]) and American swimmers (−0.48 s [−0.89, −0.08]) typically swam faster 200-m times in relay events. Random forest models predicted gold, silver, bronze and non-medal with 100%, up to 41%, up to 63%, and 93% sensitivity, respectively. Discussion Team finishing position was strongly associated with the differential time to the fastest team (mean decrease in Gini (MDG) when this variable was omitted = 31.3), world rankings of team members (average ranking MDG of 18.9), and the order of swimmers (MDG = 6.9). Differential times are based on the sum of individual swimmer’s season’s best times, and along with world rankings, reflect team strength. In contrast, the order of swimmers reflects strategy. This type of analysis could assist coaches and support staff in selecting swimmers and team orders for relay events to enhance the likelihood of success.
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Virozub, Evgenia, Oren Wiezel, Alon Wolf, and Yizhar Or. "Planar Multi-Link Swimmers: Experiments and Theoretical Investigation using “Perfect Fluid” Model." Robotica 37, no. 08 (February 18, 2019): 1289–301. http://dx.doi.org/10.1017/s0263574718001510.
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SummaryRobotic swimmers are currently a subject of extensive research and development for several underwater applications. Clever design and planning must rely on simple theoretical models that account for the swimmer’s hydrodynamics in order to optimize its structure and control inputs. In this work, we study a planar snake-like multi-link swimmer by using the “perfect fluid” model that accounts for inertial hydrodynamic forces while neglecting viscous drag effects. The swimmer’s dynamic equations of motion are formulated and reduced into a first-order system due to symmetries and conservation of generalized momentum variables. Focusing on oscillatory inputs of joint angles, we study optimal gaits for 3-link and 5-link swimmers via numerical integration. For the 3-link swimmer, we also provide a small-amplitude asymptotic solution which enables obtaining closed-form approximations for optimal gaits. The theoretical results are then corroborated by experiments and motion measurement of untethered robotic prototypes with three and five links floating in a water pool, showing a reasonable agreement between the experiments and the theoretical model.
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Hamidi Rad, Mahdi, Vincent Gremeaux, Fabien Massé, Farzin Dadashi, and Kamiar Aminian. "SmartSwim, a Novel IMU-Based Coaching Assistance." Sensors 22, no. 9 (April 27, 2022): 3356. http://dx.doi.org/10.3390/s22093356.
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Swimming coaches provide regular timed and technical feedback to swimmers and guide them efficiently in training sessions. Due to the complexity of swimmers’ performance, which is not visible in qualitative observation, quantitative and objective performance evaluation can better assist the coach in this regard. Inertial measurement units (IMUs) are used in swimming for objective performance evaluation. In this study, we propose a new performance evaluation feedback (SmartSwim) using IMU and investigate its effects on the swimmer’s weekly progress. Measurements were conducted each week with 15 competitive swimmers for 10 weeks using a Sacrum IMU. The SmartSwim report included a comprehensive representation of performance based on goal metrics of each phase extracted from the IMU signals. The swimmers were divided into two groups: the experimental and control groups. The SmartSwim report for each swimmer in the experimental group was given to the coach, who used it to adjust the training accordingly. The results showed that the experimental group outperformed the control group when comparing each swimmer, each session and the whole sessions. At the level of each individual, more members of the experimental group showed significant downward trend of average lap time (Mann-Kendall trend test, 95% confidence level). While comparing the sessions, the experimental group showed significantly lower lap time than the control group from the sixth session onwards (p-value < 0.05 from t-test). Considering all sessions, the experimental group showed significantly higher progress, lower average lap time, and more consistent records (Mann-Whitney U test at 95% confidence level) than the control group. This study demonstrated that SmartSwim can assist coaching by quantitatively assessing swimmers’ performance, leading to more efficient training.
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Hinrichs, Richard N., and Scott P. McLean. "A Mathematical Model of Competitive Swimming in Pools with Currents." International Journal of Sport Biomechanics 7, no. 2 (May 1991): 163–74. http://dx.doi.org/10.1123/ijsb.7.2.163.
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Swimmers may be placed at a disadvantage when water in a pool is actively circulated during competition. This circulation may produce currents in specific lanes which add to a swimmer’s speed in one direction and subtract from it in the other direction. This article presents a mathematical model of swimming in a lane with a current. It predicts that even small currents can add significantly to a swimmer’s race time. The effects of the current will not equal out over an even number of lengths swum because the swimmer always loses more time swimming against the current than he or she gains from swimming with the current. Mathematical simulations of races of various distances show that the losses in time can range from 100ths of a second in a 100-m sprint to several seconds in the longer distances. Since circulating water may create currents only in specific lanes, some swimmers may be placed at a disadvantage compared to others. A simple solution to the problem of currents is suggested.
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Chambrion, Thomas, Laetitia Giraldi, and Alexandre Munnier. "Optimal strokes for driftless swimmers: A general geometric approach." ESAIM: Control, Optimisation and Calculus of Variations 25 (2019): 6. http://dx.doi.org/10.1051/cocv/2017012.
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Swimming consists by definition in propelling through a fluid by means of bodily movements. Thus, from a mathematical point of view, swimming turns into a control problem for which the controls are the deformations of the swimmer. The aim of this paper is to present a unified geometric approach for the optimization of the body deformations of so-called driftless swimmers. The class of driftless swimmers includes, among other, swimmers in a 3D Stokes flow (case of micro-swimmers in viscous fluids) or swimmers in a 2D or 3D potential flow. A general framework is introduced, allowing the complete analysis of five usual nonlinear optimization problems to be carried out. The results are illustrated with examples coming from the literature and with an in-depth study of a swimmer in a 2D potential flow. Numerical tests are also provided.
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van Rees, Wim M., Mattia Gazzola, and Petros Koumoutsakos. "Optimal morphokinematics for undulatory swimmers at intermediate Reynolds numbers." Journal of Fluid Mechanics 775 (June 19, 2015): 178–88. http://dx.doi.org/10.1017/jfm.2015.283.
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Undulatory locomotion is an archetypal mode of propulsion for natural swimmers across scales. Undulatory swimmers convert transverse body oscillations into forward velocity by a complex interplay between their flexural movements, morphological features and the fluid environment. Natural evolution has produced a wide range of morphokinematic examples of undulatory swimmers that often serve as inspiration for engineering devices. It is, however, unknown to what extent natural swimmers are optimized for hydrodynamic performance. In this work, we reverse-engineer the morphology and gait for fast and efficient swimmers by coupling an evolution strategy to three-dimensional direct numerical simulations of flows at intermediate Reynolds numbers. The fastest swimmer is slender with a narrow tail fin and performs a sequence of C-starts to maximize its average velocity. The most efficient swimmer combines moderate transverse movements with a voluminous head, tapering into a streamlined profile via a pronounced inflection point. These optimal solutions outperform anguilliform swimming zebrafish in both efficiency and speed. We investigate the transition between morphokinematic solutions in the speed–energy space, laying the foundations for the design of high-performance artificial swimming devices.
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Maity, Ruma, and P. S. Burada. "Chemotaxis of two chiral squirmers." Physics of Fluids 35, no. 4 (April 2023): 043611. http://dx.doi.org/10.1063/5.0139016.
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External gradients can strongly influence the collective behavior of microswimmers. In this paper, under an external linear chemical gradient, we study the behavior of two hydrodynamically interacting self-propelled chiral swimmers in the low-Reynolds number regime. We use the generalized squirmer model called the chiral squirmer, a spherically shaped body with an asymmetric surface slip velocity, to represent the swimmer. We find that the external gradient favors the attraction between the swimmers and, in some situations, leads to a bounded state in which the swimmers move in a highly synchronous manner. Furthermore, due to this cooperative motion, these swimmers reach the chemical target faster than individual swimmers. This study may help in understanding the collective behavior of chiral swimmers and in designing synthetic microswimmers for targeted drug delivery.
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Dingley, Andrew A., David B. Pyne, and Brendan Burkett. "Phases of the Swim-start in Paralympic Swimmers Are Influenced by Severity and Type of Disability." Journal of Applied Biomechanics 30, no. 5 (October 2014): 643–48. http://dx.doi.org/10.1123/jab.2013-0321.
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Disabilities in Paralympic swimming could impact a swimmer’s ability to execute an effective swim-start. We examined how swim-start performance differed between severity and type of physical disability. Swim-starts were measured in 55 elite Paralympic swimmers from eight different Paralympic classes; S14, S13, S10-S6, S3 grouped as no- (classes S13 & S14), low- (S9 & S10), mid- (S7 & S8) or high- (≤ S6) severity of physical disability and also by type of physical disability (upper, lower, and palsy) to provide meaningful comparisons. The swimmer’s competitive level was determined by the international point score (IPS). Swimmers with no physical disability were significantly faster in most swim-start phases compared with those with physical disabilities, as were swimmers with low-severity disabilities compared with the mid- and high-severity groups. Block velocity was highly negatively correlated (r= –0.57 to –0.86) with 15-m swimming time for all groups except high-severity disabilities. Free-swim velocity is a priority area for improving swim-starts for swimmers regardless of disability, given large correlations between this measure and IPS. Swimmers with lower body or high-severity disabilities spent a smaller percentage of time overall in the underwater phase. Assessment of four specific phases of the swim-start highlight distinctive priorities for coaches working with Paralympic swimmers in an applied biomechanical manner.
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Ye, Chengwei, Jia Liu, Xinyu Wu, Ben Wang, Li Zhang, Yuanyi Zheng, and Tiantian Xu. "Hydrophobicity Influence on Swimming Performance of Magnetically Driven Miniature Helical Swimmers." Micromachines 10, no. 3 (March 6, 2019): 175. http://dx.doi.org/10.3390/mi10030175.
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Helical microswimmers have been involved in a wide variety of applications, ranging from in vivo tasks such as targeted drug delivery to in vitro tasks such as transporting micro objects. Over the past decades, a number of studies have been established on the swimming performance of helical microswimmers and geometrical factors influencing their swimming performance. However, limited studies have focused on the influence of the hydrophobicity of swimmers’ surface on their swimming performance. In this paper, we first demonstrated through theoretical analysis that the hydrophobicity of swimmer’s surface material of the swimmer does affect its swimming performance: the swimmer with more hydrophobic surface is exerted less friction drag torque, and should therefore exhibit a higher step-out frequency, indicating that the swimmer with more hydrophobic surface should have better swimming performance. Then a series of experiments were conducted to verify the theoretical analysis. As a result, the main contribution of this paper is to demonstrate that one potential approach to improve the helical microswimmers’ swimming performance could be making its surface more hydrophobic.
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Thakrar, Dr Zalak, Krupal J. Buddhadev, Harsh D. Bhatt, Nakul H. Bhadrecha, and Mathan D. Bhogayata. "Swimmer Safety Alert System for Encounters with Unidentified Marine Aquatic Animals." International Journal of Innovative Research in Computer Science and Technology 12, no. 4 (July 2024): 47–51. http://dx.doi.org/10.55524/ijircst.2024.12.4.8.
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The perilous encounters between swimmers and marine animals pose a significant risk to both human safety and the well-being of aquatic creatures. Every year, a distressing number of swimmers succumb to attacks by marine animals, often with neither party at fault. In response to this ongoing threat, the Swimmer Alert System emerges as a groundbreaking technology aimed at safeguarding both humans and marine life, ensuring their mutual protection without harm to either party. By utilizing advanced sensors and real-time monitoring, this system detects the presence of potentially dangerous marine animals in swimmer-populated areas, alerting both swimmers and authorities to take necessary precautions. Through proactive intervention and awareness, the Swimmer Alert System endeavors to mitigate the frequency of unfortunate incidents, fostering harmonious coexistence between humans and the marine ecosystem. As a result, lives are spared, and ecosystems remain undisturbed, offering a promising solution to a longstanding challenge.
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Krishnamurthy, Deepak, and Ganesh Subramanian. "Collective motion in a suspension of micro-swimmers that run-and-tumble and rotary diffuse." Journal of Fluid Mechanics 781 (September 28, 2015): 422–66. http://dx.doi.org/10.1017/jfm.2015.473.
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Recent experiments have shown that suspensions of swimming micro-organisms are characterized by complex dynamics involving enhanced swimming speeds, large-scale correlated motions and enhanced diffusivities of embedded tracer particles. Understanding this dynamics is of fundamental interest and also has relevance to biological systems. The observed collective dynamics has been interpreted as the onset of a hydrodynamic instability, of the quiescent isotropic state of pushers, swimmers with extensile force dipoles, above a critical threshold proportional to the swimmer concentration. In this work, we develop a particle-based model to simulate a suspension of hydrodynamically interacting rod-like swimmers to estimate this threshold. Unlike earlier simulations, the velocity disturbance field due to each swimmer is specified in terms of the intrinsic swimmer stress alone, as per viscous slender-body theory. This allows for a computationally efficient kinematic simulation where the interaction law between swimmers is knowna priori. The neglect of induced stresses is of secondary importance since the aforementioned instability arises solely due to the intrinsic swimmer force dipoles.Our kinematic simulations include, for the first time, intrinsic decorrelation mechanisms found in bacteria, such as tumbling and rotary diffusion. To begin with, we simulate so-called straight swimmers that lack intrinsic orientation decorrelation mechanisms, and a comparison with earlier results serves as a proof of principle. Next, we simulate suspensions of swimmers that tumble and undergo rotary diffusion, as a function of the swimmer number density$(n)$, and the intrinsic decorrelation time (the average duration between tumbles,${\it\tau}$, for tumblers, and the inverse of the rotary diffusivity,$D_{r}^{-1}$, for rotary diffusers). The simulations, as a function of the decorrelation time, are carried out with hydrodynamic interactions (between swimmers) turned off and on, and for both pushers and pullers (swimmers with contractile force dipoles). The ‘interactions-off’ simulations allow for a validation based on analytical expressions for the tracer diffusivity in the stable regime, and reveal a non-trivial box size dependence that arises with varying strength of the hydrodynamic interactions. The ‘interactions-on’ simulations lead us to our main finding: the existence of a box-size-independent parameter that characterizes the onset of instability in a pusher suspension, and is given by$nUL^{2}{\it\tau}$for tumblers and$nUL^{2}/D_{r}$for rotary diffusers; here,$U$and$L$are the swimming speed and swimmer length, respectively. The instability manifests as a bifurcation of the tracer diffusivity curves, in pusher and puller suspensions, for values of the above dimensionless parameters exceeding a critical threshold.
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Yuan, Zhi-Ming, Mingxin Li, Chun-Yan Ji, Liang Li, Laibing Jia, and Atilla Incecik. "Steady hydrodynamic interaction between human swimmers." Journal of The Royal Society Interface 16, no. 150 (January 2019): 20180768. http://dx.doi.org/10.1098/rsif.2018.0768.
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This study focuses on the hydrodynamic interaction between two or three human swimmers in competitive swimming. Although the swimming performance of a single swimmer has been widely examined, studies on the interaction between multiple competitive swimmers are very rare. Experiments showed evidence that the drag of a swimmer could be modified by the existence of the other adjacent competitors (Chatard & Wilson. 2003 Med. Sci. Sports Exerc . 35 , 1176–1181. ( doi:10.1249/01.MSS.0000074564.06106.1F )). The following questions arise: (1) what mechanism determines the interaction; (2) which position experiences drag reduction or drag increase; (3) how much can drag be reduced or increased in a formation? According to the authors' knowledge, such questions have not been addressed by any published literature. Therefore, the main purpose of this study is to find the mechanism of the hydrodynamic interaction between human swimmers and to quantify this interactive effect by using a steady potential flow solver. The free-surface effect was fully taken into account in our calculations. We firstly calculated the wave drag of a swimmer swimming solely in an open swimming pool. Then we calculated the wave drag of the same swimmer when he/she swam in the wake region of one or two leading swimmers. The results showed that the hydrodynamic interaction made a significant contribution to the drafter's wave drag. By following a leading swimmer, a drafter at wave-riding positions could save up to 63% of their wave drag at speed of 2.0 m s −1 and lateral separation of 2.0 m. Particularly, when a drafter is following two side-by-side leaders, the drag reduction could even be doubled. To the authors' knowledge, this study is the first to demonstrate that the hydrodynamic interaction between human swimmers can best be described and explained in terms of wave interference effect on the free water surface. When the wave cancellation effect is observed, the wave drag of a drafter could be minimized, and this wave cancellation effect can be achieved only when the drafter is in a wave-riding position.
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Allen, Sian V., Tom J. Vandenbogaerde, David B. Pyne, and Will G. Hopkins. "Predicting a Nation’s Olympic-Qualifying Swimmers." International Journal of Sports Physiology and Performance 10, no. 4 (May 2015): 431–35. http://dx.doi.org/10.1123/ijspp.2014-0314.
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Talent identification and development typically involve allocation of resources toward athletes selected on the basis of early-career performance.Purpose:To compare 4 methods for early-career selection of Australia’s 2012 Olympic-qualifying swimmers.Methods:Performance times from 5738 Australian swimmers in individual Olympic events at 101 competitions from 2000 to 2012 were analyzed as percentages of world-record times using 4 methods that retrospectively simulated early selection of swimmers into a talent-development squad. For all methods, squad-selection thresholds were set to include 90% of Olympic qualifiers. One method used each swimmer’s given-year performance for selection, while the others predicted each swimmer’s 2012 performance. The predictive methods were regression and neural-network modeling using given-year performance and age and quadratic trajectories derived using mixed modeling of each swimmer’s annual best career performances up to the given year. All methods were applied to swimmers in 2007 and repeated for each subsequent year through 2011.Results:The regression model produced squad sizes of 562, 552, 188, 140, and 93 for the years 2007 through 2011. Corresponding proportions of the squads consisting of Olympic qualifiers were 11%, 11%, 32%, 43%, and 66%. Neural-network modeling produced similar outcomes, but the other methods were less effective. Swimming Australia’s actual squads ranged from 91 to 67 swimmers but included only 50−74% of Olympic qualifiers.Conclusions:Large talent-development squads are required to include most eventual Olympic qualifiers. Criteria additional to age and performance are needed to improve early selection of swimmers to talent-development squads.
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Berdakin, Ivan, V. I. Marconi, and Adolfo J. Banchio. "Boosting micromachine studies with Stokesian dynamics." Physics of Fluids 34, no. 3 (March 2022): 037102. http://dx.doi.org/10.1063/5.0083528.
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Artificial microswimmers, nano- and microrobots, are essential in many applications from engineering to biology and medicine. We present a Stokesian dynamics study of the dynamical properties and efficiency of one of the simplest artificial swimmers, the three linked spheres swimmer (TLS), extensively shown to be an excellent and model example of a deformable micromachine. Results for two different swimming strokes are compared with an approximate solution based on point force interactions. While this approximation accurately reproduces the solutions for swimmers with long arms and strokes of small amplitude, it fails when the amplitude of the stroke is such that the spheres come close together, a condition where indeed the largest efficiencies are obtained. We find that swimmers with a “square stroke cycle” result more efficient than those with “circular stroke cycle” when the swimmer arms are long compared with the sphere radius, but the differences between the two strokes are smaller when the arms of the swimmers are short. This extended theoretical research of TLS incorporates a much precise description of the swimmer hydrodynamics, demonstrating the relevance of considering the finite size of the constitutive microswimmers spheres. This work expects to trigger future innovative steps contributing to the design of micro- and nanomachines and its applications.
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Amna Saleh Team, Yasar Saibah Ali. "The effect of special strength exercises based on parallel training (Circuit Training) in developing some physiological variables and achieving 100 breaststroke swimming for young people." Mustansiriyah Journal of Sports Science 6, no. 2 (April 7, 2024): 189–204. http://dx.doi.org/10.62540/mjss.2024.2.6.13.
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Special strength training exercises used by swimmers in order to build physical capabilities and improve physiological adaptation, because the success of the training process is measured by the extent of progress achieved by the swimmer and parallel training (Circuit Training) is a very effective and versatile method that targets multiple aspects of With specific breaks that can focus on strength You perform these exercises sequentially, moving from exercise to exercise with limited breaks, .importance of research in an attempt Employing the mechanism of giving exercises and training methods to link between different sports sciences The research problem noted that many swimmers have weakness when performing swimming races (100 m) chest due to the weakness of the physical and motor abilities of swimmers as the physical, motor and skill integration gives the swimmer the appropriate opportunity to do the correct motor work. of swimmers of the Peace Club and conducted the pre-tests and then applied the exercises on this sample and then the post-tests and concluded that the use of special strength exercises according to the training
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Simões, Paulo, José Vasconcelos-Raposo, António Silva, and Helder Fernandes. "Effects of a Process-Oriented Goal Setting Model on Swimmer's Performance." Journal of Human Kinetics 32, no. 1 (May 1, 2012): 65–76. http://dx.doi.org/10.2478/v10078-012-0024-6.
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Effects of a Process-Oriented Goal Setting Model on Swimmer's Performance The aim of this work was to study the impact of the implementation of a mental training program on swimmers' chronometric performance, with national and international Portuguese swimmers, based on the goal setting model proposed by Vasconcelos-Raposo (2001). This longitudinal study comprised a sample of nine swimmers (four male and five female) aged between fourteen and twenty, with five to eleven years of competitive experience. All swimmers were submitted to an evaluation system during two years. The first season involved the implementation of the goal setting model, and the second season was only evaluation, totaling seven assessments over the two years. The main results showed a significant improvement in chronometric performance during psychological intervention, followed by a reduction in swimmers' performance in the second season, when there was no interference from the investigators (follow-up).
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Farutin, A., H. Wu, W. F. Hu, S. Rafaï, P. Peyla, M. C. Lai, and C. Misbah. "Analytical study for swimmers in a channel." Journal of Fluid Mechanics 881 (October 24, 2019): 365–83. http://dx.doi.org/10.1017/jfm.2019.751.
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There is an overabundance of microswimmers in nature, including bacteria, algae, mammalian cells and so on. They use flagellum, cilia or global shape changes (amoeboid motion) to move forward. In the presence of confining channels, these swimmers exhibit often non-trivial behaviours, such as accumulation at the wall, navigation and so on, and their swimming speed may be strongly influenced by the geometric confinement. Several numerical studies have reported that the presence of walls either enhances or reduces the swimming speed depending on the nature of the swimmer, and also on the confinement. The purpose of this paper is to provide an analytical explanation of several previously obtained numerical results. We treat the case of amoeboid swimmers and the case of squirmers having either a tangential (the classical situation) or normal velocity prescribed at the swimmer surface (pumper). For amoeboid motion we consider a quasi-circular swimmer which allows us to tackle the problem analytically and to extract the equations of the motion of the swimmer, with several explicit analytical or semi-analytical solutions. It is found that the deformation of the amoeboid swimmer as well as a high enough order effect due to confinement are necessary in order to account for previous numerical results. The analytical theory accounts for several features obtained numerically also for non-deformable swimmers.
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Suppes, Laura, Kacey Ernst, Leif Abrell, and Kelly Reynolds. "Validation of Questionnaire Methods to Quantify Recreational Water Ingestion." International Journal of Environmental Research and Public Health 15, no. 11 (November 1, 2018): 2435. http://dx.doi.org/10.3390/ijerph15112435.
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Swimming pool water ingestion volumes are necessary for assessing infection risk from swimming. Pool water ingestion volumes can be estimated by questionnaire or measuring a chemical tracer in swimmer urine. Questionnaires are often preferred to the chemical tracer method because surveys are less time consuming, but no research exists validating questionnaires accurately quantify pool water ingestion volumes. The objective of this study was to explore if questionnaires are a reliable tool for collecting pool water ingestion volumes. A questionnaire was issued at four pool sites in Tucson, Arizona to 46 swimmers who also submitted a urine sample for analyzing cyanuric acid, a chemical tracer. Perceived ingestion volumes reported on the questionnaire were compared with pool water ingestion volumes, quantified by analyzing cyanuric acid in swimmer urine. Swimmers were asked if they swallowed (1) no water or only a few drops, (2) one to two mouthfuls, (3) three to five mouthfuls, or (4) six to eight mouthfuls. One mouthful is the equivalent of 27 mL of water. The majority (81%) of swimmers ingested <27 mL of pool water but reported ingesting >27 mL (“one mouthful”) on the questionnaire. More than half (52%) of swimmers overestimated their ingestion volume. These findings suggest swimmers are over-estimating pool water ingestion because they perceive one mouthful is <27 mL. The questionnaire did not reliably collect pool water ingestion volumes and should be improved for future exposure assessment studies. Images of the ingestion volume categories should be included on the questionnaire to help swimmers visualize the response options.
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Zhu, L., E. Lauga, and L. Brandt. "Low-Reynolds-number swimming in a capillary tube." Journal of Fluid Mechanics 726 (May 31, 2013): 285–311. http://dx.doi.org/10.1017/jfm.2013.225.
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AbstractWe use the boundary element method to study the low-Reynolds-number locomotion of a spherical model microorganism in a circular tube. The swimmer propels itself by tangential or normal surface motion in a tube whose radius is of the order of the swimmer size. Hydrodynamic interactions with the tube walls significantly affect the average swimming speed and power consumption of the model microorganism. In the case of swimming parallel to the tube axis, the locomotion speed is always reduced (respectively, increased) for swimmers with tangential (respectively, normal) deformation. In all cases, the rate of work necessary for swimming is increased by confinement. Swimmers with no force dipoles in the far field generally follow helical trajectories, solely induced by hydrodynamic interactions with the tube walls, and in qualitative agreement with recent experimental observations for Paramecium. Swimmers of the puller type always display stable locomotion at a location which depends on the strength of their force dipoles: swimmers with weak dipoles (small $\alpha $) swim in the centre of the tube while those with strong dipoles (large $\alpha $) swim near the walls. In contrast, pusher swimmers and those employing normal deformation are unstable and end up crashing into the walls of the tube. Similar dynamics is observed for swimming into a curved tube. These results could be relevant for the future design of artificial microswimmers in confined geometries.
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Quash, Tiffany Monique, and Angela K. Beale-Tawfeeq. "A Different View of Collegiate Swimming. Under the Umbrella of Title IX: Voices of Black Womxn Collegiate Swimmers at HBCUs." Journal of Black Sexuality and Relationships 10, no. 1-2 (June 2023): 149–68. http://dx.doi.org/10.1353/bsr.2023.a910433.
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Abstract: Research completed by Norwood (2010), Quash (2018), and Waller and Nor-wood (2009) examined the experiences of Black Womxn swimmers. These authors identified swimming participation’s constraints and its impact on Black Womxn in collegiate and/or recreational settings. Minimal research encompasses a summation of the generational and institutional experiences of Black Womxn Collegiate Swimmers from Historically Black Colleges and Universities (HBCUs) which no longer exist. Despite the success and experiences of Black Collegiate Swimmers and Olympians Lia Neal and Simone Manuel (both from Stanford University), and Natalie Hinds (from the University of Florida) who earned the top three places in the monumental 2015 Division I Swimming and Diving Championships (“ Three college swimmers make history at ncaa championship ,” 2015) from predominantly white institutions, little is known about one’s introduction to the sport, familial support, and the team culture as experienced by a Black Womxn swimmer and more so from an HBCU swimmer. This study was an opportunity to recognize the experiences of self-identified Black Womxn Collegiate Swimmers from Historically Black Colleges and Universities and the closure of these competitive swim programs. Noting the importance of race, gender, and class in a sport that is dominated by white cisgender men and womxn, this narrative inquiry study aims to provide a voice for Black Womxn who swam for athletic programs that Title IX, as a federal law, were unable to protect.
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Tor, Elaine, David L. Pease, and Kevin A. Ball. "How Does Drag Affect the Underwater Phase of a Swimming Start?" Journal of Applied Biomechanics 31, no. 1 (February 2015): 8–12. http://dx.doi.org/10.1123/jab.2014-0081.
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During the underwater phase of the swimming start drag forces are constantly acting to slow the swimmer down. The current study aimed to quantify total drag force as well as the specific contribution of wave drag during the underwater phase of the swimming start. Swimmers were towed at three different depths (surface, 0.5 m, 1.0 m) and four speeds (1.6, 1.9, 2.0, 2.5 m·s–1), totaling 12 conditions. Wave drag and total drag were measured for each trial. Mixed modeling and plots were then used to determine the relationships between each towing condition and the amount of drag acting on the swimmer. The results of this study show large decreases in total drag as depth increases, regardless of speed (–19.7% at 0.5 m and –23.8% at 1.0 m). This is largely due to the significant reduction in wave drag as the swimmers traveled at greater depth. It is recommended that swimmers travel at least 0.5 m below the surface to avoid excessive drag forces. Swimmers should also perform efficient breakouts when transitioning into free swimming to reduce the duration spent just below the surface where drag values are reported at their highest.
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Khalid, Ghezwan, and Ghasan Adeeb. "A Comparative Study According to Angiotensin Genetic Diversity As Indicator for 30m Freestyle Swimming in Youth aged (15 – 16) Year Old." Journal of Physical Education 33, no. 2 (June 28, 2021): 31–38. http://dx.doi.org/10.37359/jope.v33(2)2021.1139.
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The orientation process done by coaches and academicians in swimmers’ selection was based on apparent indicators and somebody and physical indicators. Yet the development in genetic studies and applying it to each swimmer will be more accurate. The researchers aimed at studying the athlete’s genes, performance genes based on genetic studies so as to compare among the three versions of the gene and matching it to the corresponding physical abilities. This study sheds the light on swimmers’ orientation and selection through comparing genes a matter that can help specify what is suitable for 30m freestyle swimmers.
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Dutia, Iain, Declan Curran, Adam Donohoe, Emma Beckman, and Sean Michael Tweedy. "Time cost associated with sports participation for athletes with high support needs: a time-motion analysis of tasks required for para swimming." BMJ Open Sport & Exercise Medicine 8, no. 4 (October 2022): e001418. http://dx.doi.org/10.1136/bmjsem-2022-001418.
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ObjectivesPeople with cerebral palsy and high support needs (CP&HSN) are profoundly inactive but also under-represented in studies evaluating physical activity interventions. Reasons for their exclusion have not been evaluated. We hypothesised that CP&HSN would be associated with high time costs of preparatory activities (eg, getting dressed/undressed), possibly contributing to low participation and under-representation. Accordingly, this pilot study aimed to: (1) evaluate whether the time required for preparatory activities was extremely different (≥3 SD) between swimmers with and without CP&HSN; and (2) provide a qualitative indication of the preparatory tasks undertaken by swimmers with CP&HSN.MethodsEach of three experienced (5 years) para swimmers with CP&HSN and 20 non-disabled swimmers were timed entering and then exiting the pool on three occasions. Mean entry and exit time for each para swimmer was compared with the group mean for non-disabled swimmers, and differences of greater than 3.0 SD were considered extreme. A qualitative description of the tasks completed by the para swimmers was recorded.ResultsThe differences in time costs between para and non-disabled swimmers met the criterion of extreme. Pool entry times for para swimmers were 8–13 times greater (Effect size = 4.1–8.7). Pool exit times were 6–10 times greater (ES=7.0–9.5). 90% of tasks completed by para swimmers required personal assistance or wheeled mobility.ConclusionsThis pilot study suggests that, compared with non-disabled swimmers, time costs for preparation to commence or depart training are extremely high for swimmers with CP&HSN. Further research is required to evaluate the veracity of these findings.
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Sandage, Mary J., Lauren A. Dunn, Ryleigh Edwards, and Sara Ann Pope. "Implications of Compression Race Suit on Forced Vital Capacity: Assessment Considerations for Paradoxical Vocal Fold Motion in Competitive Female Swimmers." American Journal of Speech-Language Pathology 29, no. 2 (May 8, 2020): 732–40. http://dx.doi.org/10.1044/2019_ajslp-19-00185.
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Purpose The purpose of this investigation was to quantify the extent to which forced vital capacity (FVC) in competitive swimmers may differ from nonswimmers and determine if compression race suits reduced FVC when compared to practice swimsuits. Identification of the differences in FVC between swimmers and nonswimmers as well as pulmonary function differences secondary to swimsuit construction may inform assessment of the competitive swimmer with paradoxical vocal fold motion (PVFM). Method Using a prospective, mixed within- and between-groups, repeated measures design with 10 female competitive swimmers and 13 female nonswimmers, FVC was measured and compared between the two groups. Further FVC assessment was completed with the swimmers to identify FVC differences between a practice suit and a compression racing suit. Results FVC in swimmers was significantly larger than FVC in nonswimmers by over 1 L. The predicted FVC volumes were significantly smaller than the actual FVC volumes for swimmers. No significant differences were identified between the practice swimsuit and the compression race suit or between the predicted and actual FVCs for the nonswimmer group. Conclusions Swimmers have unique pulmonary function and physiology that require consideration during the assessment for PVFM to ascertain the extent to which the pulmonary system may be compromised from PVFM, reduced exercise intensity, or both. Knowledge of differential diagnoses and adequate characterization of pulmonary volumes in swimmers will improve assessment processes.
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Sfyri, Eleni, Vasiliki Kefala, Effie Papageorgiou, Athena Mavridou, Apostolos Beloukas, and Efstathios Rallis. "Viral Cutaneous Infections in Swimmers: A Preliminary Study." Water 13, no. 23 (December 2, 2021): 3401. http://dx.doi.org/10.3390/w13233401.
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Molluscum contagiosum (MC) and warts are common viral infections of the skin. Data regarding the prevalence of MC and verruca in swimmers are very poor and lacking in the literature. The purpose of this study was to determine the incidence of Molluscum Contagiosum (MC) and warts cases among young competitive swimmers participating in Greek swimming clubs. Of 244 swimmers enrolled in this study, 12.3% reported MC and 43% warts, during their swimming career, diagnosed and treated by dermatologists. There was no difference between sexes for MC but diagnoses of warts were higher in females. Axillae and trunk were the most common sites of primary infection for MC but warts mainly appeared on the soles. The incidence of MC and warts in swimmers who use outdoor facilities was higher. In our study, the incidence of warts and MC in Greek swimmers is considered high. Moist walking surfaces, placing towels on locker room benches, and sharing equipment are behaviors that cause infections. An early diagnosis of warts and MC lesions must be implemented in every swimmer through dermatological examination. Taking proper measures for reducing the risk of warts and MC transmission in Greek swimmers is mandatory.
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Toppaladoddi, S., and N. J. Balmforth. "Slender axisymmetric Stokesian swimmers." Journal of Fluid Mechanics 746 (April 1, 2014): 273–99. http://dx.doi.org/10.1017/jfm.2014.120.
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AbstractSlender-body theory is used to study axisymmetric swimmers propelled by motions of their surfaces. To leading order, the locomotion speed is given by an integral involving the fluid velocity at the surface of the slender body. Locomotion speeds are calculated for fixed-shape swimmers with prescribed fluid surface velocities and for impermeable swimmers driven by propagating surface waves. Next, the internal mechanics is considered, modelling the swimmer as a viscous fluid bounded by an elastic shell. Prescribed forces are exerted on the shell to drive both the internal and external fluid flow and the surface waves. The internal fluid mechanics is determined using lubrication theory. Locomotion speeds are calculated for transverse and longitudinal waves of surface deformation, and the efficiency of the motions is determined. Transverse surface waves are both weaker and less efficient at driving locomotion than longitudinal waves. The results indicate how estimates of swimming speed based on nearly spherical swimmers with low-amplitude surface waves can be adapted for slender swimmers with nonlinear surface deformations.
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Nakashima, Motomu, and Jacob Tebbe. "Analysis of Swimming Motion for a Swimmer with Unilateral Transradial Deficiency to Develop Better Training Paddles." Proceedings 49, no. 1 (June 15, 2020): 9. http://dx.doi.org/10.3390/proceedings2020049009.
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Devices for swimmers with arm amputation/deficiency have not been developed a lot and therefore many improvements can be realized. Although swimmers often use paddles during training, paddles on the market are basically for swimmers without amputation/deficiency. The objective of this study was to analyze the swimming motion of a swimmer with unilateral transradial deficiency and to obtain the findings for development of better training paddles. The crawl stroke was filmed for a swimmer with unilateral transradial deficiency. The body geometry as well as the joint motion based on the filmed images were put into the swimming human simulation model SWUM, and a simulation was conducted. From the simulation, the coordination and thrusts of both limbs were obtained and fully discussed. Overall, significant asymmetry between the intact and deficient limbs was found. It was also found that the deficient limb contributed to the propulsion only for 7% of the intact limb.
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Muhsin, Ahmed Thamer. "Analytical Comparative Study of Some Kinematic Variables Affecting the Distances of 200 m. Freestyle Race." Journal of Physical Education 32, no. 3 (September 28, 2020): 107–13. http://dx.doi.org/10.37359/jope.v32(3)2020.1026.
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The study aimed at identifying some kinematic variables affecting the distances of 200m freestyle race among the swimmers of the Specialized School for Swimming. Three (3) swimmers have been intentionally chosen to be the subjects of the study. The kinematic variables of each player have been extracted by the motor analysis (kinovea) program and their data values then compared. In light of the results, the researcher found out clear big differences in the values of these variables among the swimmers themselves and between each distance of the race distances for each swimmer which led to a big variation in the achievement (final time). A matter that requires reforming procedures in the technical performance and physical characteristics development for the swimmers of the Specialized School in 200m freestyle event in order to reduce the final time (improving achievement).
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Han, Endao, Lailai Zhu, Joshua W. Shaevitz, and Howard A. Stone. "Low-Reynolds-number, biflagellated Quincke swimmers with multiple forms of motion." Proceedings of the National Academy of Sciences 118, no. 29 (July 15, 2021): e2022000118. http://dx.doi.org/10.1073/pnas.2022000118.
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In the limit of zero Reynolds number (Re), swimmers propel themselves exploiting a series of nonreciprocal body motions. For an artificial swimmer, a proper selection of the power source is required to drive its motion, in cooperation with its geometric and mechanical properties. Although various external fields (magnetic, acoustic, optical, etc.) have been introduced, electric fields are rarely utilized to actuate such swimmers experimentally in unbounded space. Here we use uniform and static electric fields to demonstrate locomotion of a biflagellated sphere at low Re via Quincke rotation. These Quincke swimmers exhibit three different forms of motion, including a self-oscillatory state due to elastohydrodynamic–electrohydrodynamic interactions. Each form of motion follows a distinct trajectory in space. Our experiments and numerical results demonstrate a method to generate, and potentially control, the locomotion of artificial flagellated swimmers.
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Withers, Archie, and Sergio Maldonado. "On the swimming strategies to escape a rip current: a mathematical approach." Natural Hazards 108, no. 2 (April 22, 2021): 1449–67. http://dx.doi.org/10.1007/s11069-021-04740-7.
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AbstractRip currents represent significant hazards to swimmers all around the world. The danger arises when a misinformed swimmer uses an inadequate strategy to escape the rip, such as fighting the current directly. This can lead to fatigue, panic, and in some cases drowning. There exists a range of strategies put forward by experts (both lifeguards and scientists) to escape rip currents. However, these recommendations are based on a limited number of scientific studies and there is still much discrepancy surrounding the best strategy to escape a rip. Thus, here we present a simple, physics-based theoretical model aimed at assessing different escape strategies in terms of their associated ‘energetic cost’ (in work and power) for any given rip current and swimmer’s proficiency level. Many combinations of swimmers and rips are considered, including both idealised and a realistic rip current. Our quantitative results back the common knowledge that swimming against the rip (which is strongly discouraged by lifeguards) is almost universally the worst possible strategy, especially when compared against strategies favoured by experts, such as floating with the current before attempting to swim back to the shore. For a realistic rip, our results suggest that swimming directly against the rip can require several times more power from the swimmer than other strategies advised by lifeguards, thus lending further scientific support to experts’ recommendations. This study may help promote education around the dangers posed by rip currents and how best to address them.
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Thompson, Kevin, Stephen Garland, and Fiona Lothian. "Assessment of an International Breaststroke Swimmer Using the 7 × 200-m Step Test." International Journal of Sports Physiology and Performance 1, no. 2 (June 2006): 172–75. http://dx.doi.org/10.1123/ijspp.1.2.172.
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Thompson and Cooper1 observed that improvements in the swimming speed at 2-mM and 6-mM lactate concentration coincided with improvements in competitive breaststroke performances, whereas Pyne et al2 concluded that changes in swimming speed at lactate threshold were not directly associated with competition performances in a mixed-stroke group of 12 elite swimmers. This case study presents data from eleven (7 × 200 m) step tests over a 3-year period for a world-class 200-m male breaststroke swimmer. Personal-best race times were reduced by 9.5 seconds over this period. For this individual, step-test data provided valuable information with regard to the swimmer’s readiness for performance, health and training status, and nutritional habits.
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Chen, Zhi Feng, Hai Sheng Fang, and Jun Tian. "The Effects of Swimmers Posture and Swimsuit on the Hydrodynamic Performance during Underwater Swimming." Applied Mechanics and Materials 327 (June 2013): 256–62. http://dx.doi.org/10.4028/www.scientific.net/amm.327.256.
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Computational calculation is conducted to evaluate the effects of the swimmers posture and swimsuit on the hydrodynamic performance using the Fluent code. Both steady and unsteady models are applied on a 2D geometry. It is found that the swimmers posture and swimsuit play an important role on the hydrodynamic performance. The unsteady modeling reveals the vortex formation, development and separation behind the feet, and predicts the variation of the forces on the swimmer by time. The results provide a basis theoretically for the swimmer to understand the effects of posture and swimsuit on the resistive force, and then to provide tools for the optimization of underwater swimming.
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Zarrouf, L. R. "0991 The Effect Of Extending Total Sleep Time And Weighted Blankets On Teenage Swimmers Performance." Sleep 43, Supplement_1 (April 2020): A376—A377. http://dx.doi.org/10.1093/sleep/zsaa056.987.
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Abstract Introduction Effectiveness of sleep extension on performance and cognition in adult athletes has been studied extensively. Effectiveness of weighted blankets on sleep extension in children has been studied with mixed results. The effect of sleep quantity on teen competitive swimmers has not been evaluated extensively. This study investigated the effects of sleep extension and weighted blankets on performance, as well as daytime sleepiness in competitive teen swimmers. The principal investigator is a high school student and a teen-swimmer herself. Methods Study Design: Using an open label prospective approach, the pilot study will investigate swimmer’s event time changes, actigraphy findings and daytime sleepiness with sleep extension and weighted blankets. Setting/ Participants: 12 healthy swimmers on the MAKOS swim team will maintain their habitual sleep-wake schedule for a one-week; baseline period followed by a one-week sleep extension period, combined with weighted blankets use. Procedure/Protocol: The head-coach will assign event type to each participant of the study, 2 participants of the same type of event, will do the baseline timed race and initial evaluation, followed by one week of regular sleep (control). Another timed event will be done at the end of the 1st week and followed by a 2nd week of extended sleep (one hour/day) and weighted blanket. Final timed event race will be at the end of the 2nd week. Participants will fill initial, weekly questionnaires and wear a sleep tracker during the two weeks of the study. Detailed sleep and activities analysis will be obtained. Results 12 swimmers were recruited, 8 females and 4 males. All participants have been consistently with the team for more than 2 years. Age range of participants is 11- 17 years. Members of the team practiced 5 days every week with each practice lasting for 2 hours. The first timed race is scheduled to be done the first week in January. Conclusion This is the first research study to evaluate the effect of two important variables on sleep and performance in teenage swimmers. Support The authors report no financial support related to this study.
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Weber, Pascal, Georgios Arampatzis, Guido Novati, Siddhartha Verma, Costas Papadimitriou, and Petros Koumoutsakos. "Optimal Flow Sensing for Schooling Swimmers." Biomimetics 5, no. 1 (March 9, 2020): 10. http://dx.doi.org/10.3390/biomimetics5010010.
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Fish schooling implies an awareness of the swimmers for their companions. In flow mediated environments, in addition to visual cues, pressure and shear sensors on the fish body are critical for providing quantitative information that assists the quantification of proximity to other fish. Here we examine the distribution of sensors on the surface of an artificial swimmer so that it can optimally identify a leading group of swimmers. We employ Bayesian experimental design coupled with numerical simulations of the two-dimensional Navier Stokes equations for multiple self-propelled swimmers. The follower tracks the school using information from its own surface pressure and shear stress. We demonstrate that the optimal sensor distribution of the follower is qualitatively similar to the distribution of neuromasts on fish. Our results show that it is possible to identify accurately the center of mass and the number of the leading swimmers using surface only information.
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Amaro, Nuno, Daniel A. Marinho, Nuno Batalha, Mário C. Marques, and Pedro Morouço. "Reliability of Tethered Swimming Evaluation in Age Group Swimmers." Journal of Human Kinetics 41, no. 1 (July 8, 2014): 155–62. http://dx.doi.org/10.2478/hukin-2014-0043.
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AbstractThe aim of the present study was to examine the reliability of tethered swimming in the evaluation of age group swimmers. The sample was composed of 8 male national level swimmers with at least 4 years of experience in competitive swimming. Each swimmer performed two 30 second maximal intensity tethered swimming tests, on separate days. Individual force-time curves were registered to assess maximum force, mean force and the mean impulse of force. Both consistency and reliability were very strong, with Cronbach's Alpha values ranging from 0.970 to 0.995. All the applied metrics presented a very high agreement between tests, with the mean impulse of force presenting the highest. These results indicate that tethered swimming can be used to evaluate age group swimmers. Furthermore, better comprehension of the swimmers ability to effectively exert force in the water can be obtained using the impulse of force.
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Lemyre, Pierre-Nicolas, Darren C. Treasure, and Glyn C. Roberts. "Influence of Variability in Motivation and Affect on Elite Athlete Burnout Susceptibility." Journal of Sport and Exercise Psychology 28, no. 1 (March 2006): 32–48. http://dx.doi.org/10.1123/jsep.28.1.32.
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Forty-four elite swimmers (F = 19, M = 25) participated in the present study designed to examine shifts along the self-determined motivation continuum, as well as swings in negative and positive affect, to predict susceptibility to athlete burnout. Each week the participants were asked to record positive and negative affect states. Swimmers’ affect swing was calculated using mean intraindividual standard deviation scores as an indicator of intraindividual variance. Every third week the athletes’ level of self-determined motivation to participate in swimming was compiled on a self-determination index. A motivational trend slope for the whole season was computed for each swimmer. Results indicated that shifts in the quality of motivation were reliable predictors of all burnout dimensions. In addition, results of the regression analyses showed that swimmers experiencing increased variability in negative affect were more at risk for burnout. These two psychological constructs reliably predicted burnout potential in elite swimmers.
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Slaughter, Mary H., Constance B. Christ, Rachel J. Stillman, and Richard A. Boileau. "The Fat-Free Body and Subcomponents of the Fat-Free Body to Height Relationship between Swimmer and Nonswimmer Children." Pediatric Exercise Science 3, no. 4 (November 1991): 342–55. http://dx.doi.org/10.1123/pes.3.4.342.
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This study was designed to determine whether there were differences in the relationships between fat-free body (FFB) to height and the subcomponents of the FFB—bone mineral content, bone width, bone mineral index, and total body water (TBW)—to height relationships among male and female age-group swimmers and nonswimmers. The 178 subjects (ages 8-16 yrs) were grouped by gender and activity level. Least-squares regression analysis was used to test the above relationships. Although there were no statistically significant differences in the FFB to height or the subcomponents of the FFB to height relationships between swimmers and nonswimmers in the male sample, the swimmer lines depicting the relationships typically fell above those of their nonswimmer counterparts. In the female sample, the FFB and TBW to height2.4 relationships differed significantly between the two groups, with the swimmers having greater values per unit of height than the non-swimmers.
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Foo, Wee Lun, Mark A. Faghy, Andy Sparks, Josh W. Newbury, and Lewis A. Gough. "The Effects of a Nutrition Education Intervention on Sports Nutrition Knowledge during a Competitive Season in Highly Trained Adolescent Swimmers." Nutrients 13, no. 8 (August 6, 2021): 2713. http://dx.doi.org/10.3390/nu13082713.
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The aim of this study was to evaluate the effects of a seven-week nutrition education intervention on the sports nutrition knowledge (SNK) of highly trained UK adolescent swimmers. Fifteen national and international adolescent swimmers (males = 5; females = 10, 15.5 ± 1.1 years, 170.2 ± 7.5 cm, 60.3 ± 5.7 kg) participated in the study during seven consecutive weeks of the competitive swimming season. The participants received 30 min of nutrition education once per week in a classroom-based setting after they had completed their regular swim training. An undergraduate sports nutrition student delivered all nutrition education sessions and SNK questionnaires were administered to the participants pre- and post-intervention. The mean total SNK score improved by 8.3% (SD = 8.4%, 95% CI = 4.1–12.6; p = 0.006; ES = 1.0) following the nutrition education sessions. On an individual basis, ten swimmers significantly improved their total SNK score, whereas four swimmers did not improve, and one swimmer performed significantly worse after the intervention. Moreover, the swimmers’ knowledge of hydration improved by 22.2% (SD = 20.6%, 95% CI = 11.8–32.6, p = 0.004, ES = 1.1) over the seven-week timeframe, which was the only nutrition topic to have a significantly increased knowledge score. The current study therefore suggests that a nutrition education intervention can positively influence the SNK of highly trained adolescent swimmers.
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Tătulea-Codrean, Maria, and Eric Lauga. "Artificial chemotaxis of phoretic swimmers: instantaneous and long-time behaviour." Journal of Fluid Mechanics 856 (October 12, 2018): 921–57. http://dx.doi.org/10.1017/jfm.2018.718.
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Phoretic swimmers are a class of artificial active particles that has received significant attention in recent years. By making use of self-generated gradients (e.g. in temperature, electric potential or some chemical product) phoretic swimmers are capable of self-propulsion without the complications of mobile body parts or a controlled external field. Focusing on diffusiophoresis, we quantify in this paper the mechanisms through which phoretic particles may achieve chemotaxis, both at the individual and the non-interacting population level. We first derive a fully analytical law for the instantaneous propulsion and orientation of a phoretic swimmer with general axisymmetric surface properties, in the limit of zero Péclet number and small Damköhler number. We then apply our results to the case of a Janus sphere, one of the most common designs of phoretic swimmers used in experimental studies. We next put forward a novel application of generalised Taylor dispersion theory in order to characterise the long-time behaviour of a population of non-interacting phoretic swimmers. We compare our theoretical results with numerical simulations for the mean drift and anisotropic diffusion of phoretic swimmers in chemical gradients. Our results will help inform the design of phoretic swimmers in future experimental applications.
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Mitchell, Lachlan J. G., Ben Rattray, Paul Wu, Philo U. Saunders, and David B. Pyne. "Responsiveness and Seasonal Variation of a 12 × 25-m Swimming Test." International Journal of Sports Physiology and Performance 14, no. 7 (August 1, 2019): 966–71. http://dx.doi.org/10.1123/ijspp.2018-0745.
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Purpose: Critical speed (CS) and supra-CS distance capacity (D′) are useful metrics for monitoring changes in swimmers’ physiological and performance capacities. However, the utility of these metrics across a season has not been systematically evaluated in high-level swimmers. Methods: A total of 27 swimmers (mean [SD]: 18 females, age = 19.1 [2.9] y, and 9 males, age = 19.5 [1.9] y) completed the 12 × 25-m swimming test multiple times (4 [3] tests/swimmer) across a 2-y period. Season-best times in all distances for the test stroke were sourced from publicly available databases. Swimmers’ distance speciality was determined as the event with the time closest to world record. Four metrics were calculated from the 12 × 25-m test: CS, D′, peak speed, and drop-off %. Results: Guyatt responsiveness index values were calculated to ascertain the practically relevant sensitivity of each 12 × 25-m metric: CS = 1.5, peak speed = 2.3, D′ = 2.1, and drop-off % = 2.6. These values are modified effect sizes; all are large effects. Bayesian mixed modeling showed substantial between-subjects differences between genders and strokes for each variable but minimal within-subject changes across the season. Drop-off % was lower in 200-m swimmers (14.0% [3.3%]) than in 100-m swimmers (18.1% [4.1%], P = .003, effect size = 1.10). Conclusions: The 12 × 25-m test is best suited to differentiating between swimmers of different strokes and events. Further development is needed to improve its utility in quantifying meaningful changes over a season for individual swimmers.
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Jeznach, Cole, and Sarah D. Olson. "Dynamics of Swimmers in Fluids with Resistance." Fluids 5, no. 1 (January 19, 2020): 14. http://dx.doi.org/10.3390/fluids5010014.
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Micro-swimmers such as spermatozoa are able to efficiently navigate through viscous fluids that contain a sparse network of fibers or other macromolecules. We utilize the Brinkman equation to capture the fluid dynamics of sparse and stationary obstacles that are represented via a single resistance parameter. The method of regularized Brinkmanlets is utilized to solve for the fluid flow and motion of the swimmer in 2-dimensions when assuming the flagellum (tail) propagates a curvature wave. Extending previous studies, we investigate the dynamics of swimming when varying the resistance parameter, head or cell body radius, and preferred beat form parameters. For a single swimmer, we determine that increased swimming speed occurs for a smaller cell body radius and smaller fluid resistance. Progression of swimmers exhibits complex dynamics when considering hydrodynamic interactions; attraction of two swimmers is a robust phenomenon for smaller beat amplitude of the tail and smaller fluid resistance. Wall attraction is also observed, with a longer time scale of wall attraction with a larger resistance parameter.
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Ferraz, Ricardo, Luis Branquinho, Renata Loupo, Henrique Neiva, and Daniel Marinho. "The relationship between anthropometric characteristics and sports performance in national-level young swimmers." European Journal of Human Movement 45 (2020): 12–25. http://dx.doi.org/10.21134/eurjhm.2020.45.2.
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The main aim of this study was to verify associations between the anthropometric characteristics of young swimmers of different genders and different competitive levels with sports performance in 50m and 400m freestyle races at different levels (U-13 - Swimmers A and U-12 - Swimmers B). In addition, it was also intended to investigate the magnitude of the correlations between some specific variables (i.e., height, weight and wingspan) and the swimming performance. All participants were analyzed, regarding their anthropometric characteristics and their performance in the 50m and 400m freestyle swim. A total of 98 swimmers aged between 11-13 years old (mean ± standard deviation: 12.63 ± 0.76 years of age, 1.59 ± 0.08m height, 47.11 ± 7.82kg body weight) participated in the study. The results suggest that anthropometric characteristics have a positive relationship in the performance of swimmers when comparing genders (p< 0,01), furthermore positive linear correlations was found in height (r = 0.305 and r = 0.253, p <0.01), weight (r = 0.202 and r = 0.140, p <0.01), and wingspan (r = 0.227 and r = 0.203, p < 0.01) for 50m and 400m freestyle swim. The swimmers’ efficiency of segmental movements was related to anthropometric characteristics and strongly associated with the length of the swimmers’ segments. These results may be due to the fact that swimmers’ maturational status may have played an important role, in the observed results. In addition, when comparing genders, the height and weight values of male swimmers tended to be higher. Furthermore, the differences observed in the 50m and 400m freestyle swimming events were related to the relationship that anthropometric characteristics have on the biomechanical parameters of swimming, which influence swimming performance. This study concluded that the improvement of performance of each young national-level swimmer is strongly related to the rate of growth, development and maturation.
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Harariet, Fadila, Darmiah Darmiah, and Imam Santoso. "Hubungan Jumlah Perenang dengan Sisa Klor di Kolam Renang Antasari Banjarbaru Tahun 2016." JURNAL KESEHATAN LINGKUNGAN: Jurnal dan Aplikasi Teknik Kesehatan Lingkungan 14, no. 1 (January 2, 2017): 375. http://dx.doi.org/10.31964/jkl.v14i1.51.
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Abstract: The relationship of total swimmers with residual chlorine in the swimming pool. The swimming pool as a means of public that usually visited by the people can potentially become vehicles for spreading germs through water contaminated media pool so that sanitation should always be considered. This study aims to determine the number of swimmers in the Swimming Pool Antasari Banjarbaru, determine residual chlorine in Swimming Pool. This type of research was analytic research with cross sectional approach. The population is all water swimming pool which used by swimmers and all swimmers in the pool by sampling as much as 5 spots, using correlation analysis. The results showed the number of swimmers on average were 151 swimmers with the lowest number were 113 swimmers and the highest were 223 swimmers. Residual chlorine inside the water of swimming pool was an average of 0.73 mg/L, the standard deviation was 0.71 mg/L with the lowest number was 0.01 mg/L and the highest number was 1.49 mg / L. The results of the analysis did not prove statistically no relationship with the rest of the swimmers amount of chlorine in Swimming Pool because H0 (p = 0.679> value α = 0.05) and the value of r was -0.218 so that the relationship can not be seen. Efforts to do so that residual chlorine water in Swimming Pool in accordance with the requirements is to conduct regular inspections both manager pool and the relevant agencies, maintain the quality of residual chlorine by adding chlorine stabilizer isocyanuric, and perform administration disinfection according to the dosage required to obtain results corresponding residual chlorine required pursuant Peraturan Menteri Kesehatan RI Nomor: 416/Menkes/Per/IX/1990.
Keywords: Total swimmer; residual chlorine; swimming pool.
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Pelayo, Patrick, Michel Sidney, Tarik Kherif, Didier Chollet, and Claire Tourny. "Stroking Characteristics in Freestyle Swimming and Relationships with Anthropometric Characteristics." Journal of Applied Biomechanics 12, no. 2 (May 1996): 197–206. http://dx.doi.org/10.1123/jab.12.2.197.
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The purpose of this study was to determine the relationships between velocity, stroke length, and stroke rate in freestyle competitive events in order to compare male and female swimmers' results and assess their relationships with anthropometric characteristics. Three hundred three male and 325 female swimmers of national and international levels were tested during competition. Solutions adopted in each freestyle event had specific characteristics affecting the stroke rate/stroke length ratio according to distance of the race. Differences in velocity between men and women primarily resulted from differences in stroke length. If the velocity and stroke rate/stroke length ratio depend on the distance swum and the sex of the swimmer, this survey shows the nondiscriminating aspect of anthropometric characteristics. Although swimmers achieved very similar velocity values with different combinations of stroke length and stroke rate, one must appreciate the average time and space characteristics currently used by the best male and female swimmers to optimize their performances.
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Alba, Sandra. "Why are the Dutch so great at swimming?" Significance 21, no. 3 (June 3, 2024): 15–17. http://dx.doi.org/10.1093/jrssig/qmae040.
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Khan, Mohd Yasir, and Sujin B. Babu. "Effect of amplitude and wavelength in the cooperative motion of Taylor lines." Physics of Fluids 34, no. 6 (June 2022): 061901. http://dx.doi.org/10.1063/5.0090619.
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In the present study, we have modeled the clustering of binary Taylor line swimmers in a Newtonian fluid. The fluid is modeled using the particle-based simulation method multiparticle collision dynamics, while for the Taylor line, we use a bead spring arrangement with a sine wave passing through it using a bending wave potential. The binary swimmers have the same propulsion speed, but they differ from each other in the shape of the Taylor line ensured by different amplitudes and lengths. We observe that an optimal amplitude exists for the Taylor line swimmer leading to large clusters formation. The size distribution of the clusters was observed to follow a power-law behavior followed by an exponential cutoff. We also calculated the probability of finding a bead of the swimmer as a function of the fractional distance from the center of the bounding circle and observed that when the amplitude is close to the optimal value, the swimmer forms clusters closer to the walls; otherwise, the swimmer stays almost uniformly distributed around the bounding area. When the ratio of the amplitude is high, the clusters formed at the center of the bounding area become stable and have a wedge-shape. By calculating the speed of the swimmer as a function of the fractional distance from the center of the bounding area, we show that the swimmers speed increases with the maximum at the walls. The simulation with a smaller system has revealed that the maximum clustering happens for an amplitude parameter of [Formula: see text].
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Qin, Ke, Zonghao Zou, Lailai Zhu, and On Shun Pak. "Reinforcement learning of a multi-link swimmer at low Reynolds numbers." Physics of Fluids 35, no. 3 (March 2023): 032003. http://dx.doi.org/10.1063/5.0140662.
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The use of machine learning techniques in the development of microscopic swimmers has drawn considerable attention in recent years. In particular, reinforcement learning has been shown useful in enabling swimmers to learn effective propulsion strategies through its interactions with the surroundings. In this work, we apply a reinforcement learning approach to identify swimming gaits of a multi-link model swimmer. The swimmer consists of multiple rigid links connected serially with hinges, which can rotate freely to change the relative angles between neighboring links. Purcell [“Life at low Reynolds number,” Am. J. Phys. 45, 3 (1977)] demonstrated how the particular case of a three-link swimmer (now known as Purcell's swimmer) can perform a prescribed sequence of hinge rotation to generate self-propulsion in the absence of inertia. Here, without relying on any prior knowledge of low-Reynolds-number locomotion, we first demonstrate the use of reinforcement learning in identifying the classical swimming gaits of Purcell's swimmer for case of three links. We next examine the new swimming gaits acquired by the learning process as the number of links increases. We also consider the scenarios when only a single hinge is allowed to rotate at a time and when simultaneous rotation of multiple hinges is allowed. We contrast the difference in the locomotory gaits learned by the swimmers in these scenarios and discuss their propulsion performance. Taken together, our results demonstrate how a simple reinforcement learning technique can be applied to identify both classical and new swimming gaits at low Reynolds numbers.