44 research outputs found

    Control and Morphology Optimization of Passive Asymmetric Structures for Robotic Swimming

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    Aquatic creatures exhibit remarkable adaptations of their body to efficiently interact with the surrounding fluid. The tight coupling between their morphology, motion, and the environment are highly complex but serves as a valuable example when creating biomimetic structures in soft robotic swimmers. We focus on the use of asymmetry in structures to aid thrust generation and maneuverability. Designs of structures with asymmetric profiles are explored so that we can use morphology to `shape' the thrust generation. We propose combining simple simulation with automatic data-driven methods to explore their interactions with the fluid. The asymmetric structure with its co-optimized morphology and controller is able to produce 2.5 times the useful thrust compared to a baseline symmetric structure. Furthermore these asymmetric feather-like arms are validated on a robotic system capable of forward swimming motion while the same robot fitted with a plain feather is not able to move forward

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Underlying Event measurements in pp collisions at s=0.9 \sqrt {s} = 0.9 and 7 TeV with the ALICE experiment at the LHC

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    Controlling Maneuverability of a Bio-Inspired Swimming Robot Through Morphological Transformation: Morphology Driven Control of a Swimming Robot

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    Biology provides many examples of how body adaption can be used to achieve a change in functionality. The feather star, an underwater crinoid that uses feather arms to locomote and feed, is one such system; it releases its arms to distract prey and vary its maneuverability to help escape predators. Using this crinoid as inspiration, we develop a robotic system that can alter its interaction with the environment by changing its morphology. We propose a robot that can actuate layers of flexible feathers and detach them at will. We first optimize the geometric and control parameters for a flexible feather using a hydrodynamic simulation followed by physical experiments. Second, we provide a theoretical framework for understanding how body change affects controllability. Third, we present a novel design of a soft swimming robot ( Figure 1 ) with the ability of changing its morphology. Using this optimized feather and theoretical framework, we demonstrate, on a robotic setup, how the detachment of feathers can be used to change the motion path while maintaining the same low-level controller

    Controlling Maneuverability of a Bio-Inspired Swimming Robot Through Morphological Transformation: Morphology Driven Control of a Swimming Robot

    No full text
    Biology provides many examples of how body adaption can be used to achieve a change in functionality. The feather star, an underwater crinoid that uses feather arms to locomote and feed, is one such system; it releases its arms to distract prey and vary its maneuverability to help escape predators. Using this crinoid as inspiration, we develop a robotic system that can alter its interaction with the environment by changing its morphology. We propose a robot that can actuate layers of flexible feathers and detach them at will. We first optimize the geometric and control parameters for a flexible feather using a hydrodynamic simulation followed by physical experiments. Second, we provide a theoretical framework for understanding how body change affects controllability. Third, we present a novel design of a soft swimming robot ( Figure 1 ) with the ability of changing its morphology. Using this optimized feather and theoretical framework, we demonstrate, on a robotic setup, how the detachment of feathers can be used to change the motion path while maintaining the same low-level controller.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Learning & Autonomous Contro

    Impact of COVID-19-Related Sports Activity Disruptions on the Physical Fitness of Japanese Adolescent Athletes

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    We assessed whether the coronavirus disease 2019 (COVID-19) pandemic-related disruptions impacted the physical fitness of adolescent athletes. We reviewed the age-, sex-, and sports category-matched data of 78 adolescent athletes (divided into two groups: 2019 group = 37; 2020 group = 41) from the clinical database and investigated their height, weight, body composition, flexibility muscle strength, and jump height. We also provided questionnaires to the teams’ coaches to collect data on the duration of practice suspension due to the COVID-19 pandemic; the practice hours per week in August 2019, immediately after the suspension ended, and in August 2020; and the guidelines for the players after resuming their practice. For data analyses, we considered p ≤ 0.05 as statistically significant. The strength of knee flexion and extension was significantly lower in the 2020 group than in the 2019 group; there was no difference in the other physical fitness parameters. The practice duration in August 2019 and August 2020 was the same. COVID-19-related interruptions did not alter the athletes’ jump height, upper-limb strength, and flexibility but reduced lower-limb muscle strength. We recommend that basic strength training protocols be followed to prevent sports-related injuries after such unexpected practice interruptions

    Impact of COVID-19-Related Sports Activity Disruptions on the Physical Fitness of Japanese Adolescent Athletes

    No full text
    We assessed whether the coronavirus disease 2019 (COVID-19) pandemic-related disruptions impacted the physical fitness of adolescent athletes. We reviewed the age-, sex-, and sports category-matched data of 78 adolescent athletes (divided into two groups: 2019 group = 37; 2020 group = 41) from the clinical database and investigated their height, weight, body composition, flexibility muscle strength, and jump height. We also provided questionnaires to the teams’ coaches to collect data on the duration of practice suspension due to the COVID-19 pandemic; the practice hours per week in August 2019, immediately after the suspension ended, and in August 2020; and the guidelines for the players after resuming their practice. For data analyses, we considered p ≤ 0.05 as statistically significant. The strength of knee flexion and extension was significantly lower in the 2020 group than in the 2019 group; there was no difference in the other physical fitness parameters. The practice duration in August 2019 and August 2020 was the same. COVID-19-related interruptions did not alter the athletes’ jump height, upper-limb strength, and flexibility but reduced lower-limb muscle strength. We recommend that basic strength training protocols be followed to prevent sports-related injuries after such unexpected practice interruptions
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