scholarly journals Going beyond the kinetic chain process in a swing by using a triple pendulum model

2017 ◽  
Vol 70 (7) ◽  
pp. 656-665
Author(s):  
Sun-Hyun Youn
Keyword(s):  
Chain Process ◽  
Kinetic Chain ◽  
Triple Pendulum ◽  
Pendulum Model

Triple pendulum model involving fractional derivatives with different kernels

2016 ◽  
Vol 91 ◽  
pp. 248-261 ◽  
Author(s):  
A. Coronel-Escamilla ◽  
J.F. Gómez-Aguilar ◽  
M.G. López-López ◽  
V.M. Alvarado-Martínez ◽  
G.V. Guerrero-Ramírez
Keyword(s):  
Fractional Derivatives ◽  
Triple Pendulum ◽  
Pendulum Model

scholarly journals Competition Kinetics of the Nonbranched-Chain Addition of Free Radicals to Olefins, Formaldehyde, and Oxygen

2011 ◽  
Vol 2011 ◽  
pp. 1-19
Author(s):  
M. M. Silaev
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Binary Systems ◽  
Hydrogen Oxidation ◽  
Rate Equations ◽  
Chain Process ◽  
Kinetic Chain ◽  
Set Up ◽  
Kinetics Of ◽  
Unsaturated Component

Five reaction schemes are suggested for the initiated nonbranched-chain addition of free radicals to the multiple bonds of alkenes, formaldehyde, and oxygen. The schemes include reactions competing with chain propagation through a reactive free radical. The chain evolution stage in these schemes involves three or four types of free radicals. One of them— , , , , or —is relatively low-reactive and inhibits the chain process by shortening of the kinetic chain length. Based on the suggested schemes, nine rate equations containing one to three parameters to be determined directly are set up using quasi-steady-state treatment. These equations provide good fits for the nonmonotonic (peaking) dependences of the formation rates of the molecular addition products (1 : 1 adducts) on the concentration of the unsaturated component in liquid homogeneous binary systems consisting of a saturated component (hydrocarbon, alcohol, etc.) and an unsaturated component (olefin, formaldehyde, or dioxygen). The unsaturated compound in these systems is both a reactant and an autoinhibitor generating low-reactive free radicals. A similar kinetic description is applicable to nonbranched-chain free-radical hydrogen oxidation. The energetics of the key radical-molecule reactions is considered.

scholarly journals Optimized stable gait planning of biped robot using multi-objective evolutionary JAYA algorithm

2020 ◽  
Vol 17 (6) ◽  
pp. 172988142097634
Author(s):  
Huan Tran Thien ◽  
Cao Van Kien ◽  
Ho Pham Huy Anh
Keyword(s):  
Inverse Kinematics ◽  
Biped Robot ◽  
Step Length ◽  
Jaya Algorithm ◽  
Kinetic Chain ◽  
Biped Walking ◽  
Gait Planning ◽  
Multi Objective ◽  
Simulation And Experiment ◽  
Stable Gait

This article proposes a new stable biped walking pattern generator with preset step-length value, optimized by multi-objective JAYA algorithm. The biped robot is modeled as a kinetic chain of 11 links connected by 10 joints. The inverse kinematics of the biped is applied to derive the specified biped hip and feet positions. The two objectives related to the biped walking stability and the biped to follow the preset step-length magnitude have been fully investigated and Pareto optimal front of solutions has been acquired. To demonstrate the effectiveness and superiority of proposed multi-objective JAYA, the results are compared to those of MO-PSO and MO-NSGA-2 optimization approaches. The simulation and experiment results investigated over the real small-scaled biped HUBOT-4 assert that the multi-objective JAYA technique ensures an outperforming effective and stable gait planning and walking for biped with accurate preset step-length value.

scholarly journals EFFECTIVENESS OF PRE-SEASON PHYSICAL PERFORMANCE TESTS IN IDENTIFYING IN-SEASON LOWER EXTREMITY INJURIES IN ADOLESCENT GYMNASTS

2021 ◽  
Vol 9 (7_suppl3) ◽  
pp. 2325967121S0014
Author(s):  
Danielle A Farzanegan ◽  
Emily Francione ◽  
Nicole Melfi
Keyword(s):  
Lower Extremity ◽  
Physical Performance ◽  
Performance Tests ◽  
Kinetic Chain ◽  
Chi Square ◽  
Balance Test ◽  
Lower Extremity Injuries ◽  
Common Location ◽  
Acute Injuries ◽  
Extremity Injuries

Background: Artistic competitive gymnastics results in a wide, unique spectrum of injuries. Due to the high number of injuries and the current lack of research related to pre-competitive testing in adolescent gymnasts, it is crucial to find a method to predict the likelihood of an athlete sustaining an in-season injury. Purpose: The purpose of this study was to 1) describe the frequency and type of pre-season and in-season injuries, 2) determine if there were differences in physical performance tests between those who had a lower extremity (LE) injury in-season and those who did not, and 3) determine if there were differences in age, level, sex, BMI, sport modifications, previous injury, and current injury between those who had a LE injury and those who didn’t. Methods: Thirty-seven adolescent gymnasts (average age: 12.81 years) were included with levels ranging from 5 (novice) to 10 (elite). Participants (15 males and 22 females) were surveyed for previous and current injury. The athletes completed a performance battery before the competition season including: Lower Quarter Y-Balance Test (LQYBT), Closed Kinetic Chain dorsiflexion (CKCDF), single hop (SH), triple hop (TH), and the Functional Movement Screen (FMS). Follow-up data was collected at the end of the competitive season for comparison. The data was analyzed using descriptive methods and comparative analyses including chi-square and independent t-tests with an alpha level set at .05. Results: Sixty-five percent reported an injury in the last year and seventy-eight percent reported pre-season injuries at testing day. The most common location for pre-season injury was the ankle/foot (24% and 31% respectively). There were no differences between injured and non-injured athletes when comparing asymmetries in CKCDF, LQYBT posteromedial or posterolateral reach, hop testing, or FMS. The LQYBT-anterior scores were significantly different at p=.049 between the injured versus uninjured groups, with 91% of the in-season injury group having a difference <4cm. Similarly, the LQYBT-composite score using a cut-off of 95% was significant at p=.043 with those >95% category being more likely to get injured. There were no significant differences in demographic information comparing injury occurrence. Conclusion: The tested physical performance battery may be useful in tracking gymnasts over time, but may not be beneficial in forecasting injuries in a sport with high percentages of acute injuries. The collected injury volume may not be reflective of a standard season as COVID-19 decreased the number of competitions. Additional research to identify athletes at risk for injury requires further investigation.

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