scholarly journals In search of sports biomechanics’ holy grail: Can athlete-specific optimum sports techniques be identified?

2019 ◽  
Author(s):  
Paul Stephen Glazier ◽  
Sina Mehdizadeh
Keyword(s):  
Dynamical Systems ◽  
Holy Grail ◽  
Optimum Technique ◽  
Dynamic Landscape ◽  
Extended Practice ◽  
Technical Modifications ◽  
Sports Skills ◽  
The Mathematical Model ◽  
Near Future ◽  
Sports Biomechanics

The development of methods that can identify athlete-specific optimum sports techniques—arguably the holy grail of sports biomechanics—is one of the greatest challenges for researchers in the field. This ‘perspectives article’ critically examines, from a dynamical systems theoretical standpoint, the claim that athlete-specific optimum sports techniques can be identified through biomechanical optimisation modelling. To identify athlete-specific optimum sports techniques, dynamical systems theory suggests that a representative set of organismic constraints, along with their non-linear characteristics, needs to be identified and incorporated into the mathematical model of the athlete. However, whether the athlete will be able to adopt, and reliably reproduce, his/her predicted optimum technique will largely be dependent on his/her intrinsic dynamics. If the attractor valley corresponding to the existing technique is deep, or if the attractor valleys corresponding to the existing technique and the predicted optimum technique are in different topographical regions of the dynamic landscape, technical modifications may be challenging or impossible to reliably implement even after extended practice. The attractor layout defining the intrinsic dynamics of the athlete, therefore, needs to be determined to establish the likelihood of the predicted optimum technique being reliably attainable by the athlete. Given the limited set of organismic constraints typically used in mathematical models of athletes, combined with the methodological challenges associated with mapping the attractor layout of an athlete, it seems unlikely that athlete-specific optimum sports techniques will be identifiable through biomechanical optimisation modelling for the majority of sports skills in the near future.

Pointwise Optimal Control of Dynamical Systems Described by Constrained Coordinates

1999 ◽  
Vol 121 (4) ◽  
pp. 594-598 ◽  
Author(s):  
V. Radisavljevic ◽  
H. Baruh
Keyword(s):  
Optimal Control ◽  
Dynamical Systems ◽  
Feedback Control ◽  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Differential Algebraic Equations ◽  
Control Law ◽  
Algebraic Equations ◽  
The Stability ◽  
The Mathematical Model

A feedback control law is developed for dynamical systems described by constrained generalized coordinates. For certain complex dynamical systems, it is more desirable to develop the mathematical model using more general coordinates then degrees of freedom which leads to differential-algebraic equations of motion. Research in the last few decades has led to several advances in the treatment and in obtaining the solution of differential-algebraic equations. We take advantage of these advances and introduce the differential-algebraic equations and dependent generalized coordinate formulation to control. A tracking feedback control law is designed based on a pointwise-optimal formulation. The stability of pointwise optimal control law is examined.

scholarly journals The Verhulst-Like Equations: Integrable OΔE and ODE with Chaotic Behavior

Symmetry ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1446 ◽  
Author(s):  
Igor Andrianov ◽  
Galina Starushenko ◽  
Sergey Kvitka ◽  
Lelya Khajiyeva
Keyword(s):  
Mathematical Model ◽  
Dynamical Systems ◽  
Difference Equations ◽  
Chaotic Behavior ◽  
Logistic Equation ◽  
Deterministic System ◽  
Characteristic Parameters ◽  
Chaotic Dynamical Systems ◽  
The Mathematical Model ◽  
Continualization Procedure

In this paper, we study various variants of Verhulst-like ordinary differential equations (ODE) and ordinary difference equations (O Δ E). Usually Verhulst ODE serves as an example of a deterministic system and discrete logistic equation is a classic example of a simple system with very complicated (chaotic) behavior. In our paper we present examples of deterministic discretization and chaotic continualization. Continualization procedure is based on Padé approximants. To correctly characterize the dynamics of obtained ODE we measured such characteristic parameters of chaotic dynamical systems as the Lyapunov exponents and the Lyapunov dimensions. Discretization and continualization lead to a change in the symmetry of the mathematical model (i.e., group properties of the original ODE and O Δ E). This aspect of the problem is the aim of further research.

Simultaneous Interpreting (SI): the Holy Grail of Artificial Intelligence – An SI Practitioner’s Perspective

2017 ◽  
Vol 62 (2) ◽  
Author(s):  
Ailing Zhang
Keyword(s):  
Artificial Intelligence ◽  
Computer Program ◽  
Image Recognition ◽  
Human Performance ◽  
Rapid Progress ◽  
Holy Grail ◽  
Simultaneous Interpreting ◽  
The Past ◽  
World Class ◽  
Near Future

AbstractArtificial Intelligence (AI) has been become a household expression, especially in the past couple of years thanks to Google’s AI Computer program AlphaGo defeating a couple of world-class Go masters from Korea and China. In recent years, machines have surpassed humans in the performance of certain specific tasks, such as some aspects of image recognition. Although it is unlikely that machines will exhibit broadly-applicable intelligence comparable to or exceeding that of humans in the near future, experts forecast that rapid progress in the field of specialized AI will continue, with machines reaching and exceeding human performance on an increasing number of tasks. Simultaneous interpreting, being among the most complex of human cognitive/linguistic activities, with all the associated ergonomic elements, has been discussed profusely as one of the most likely to be taken over by AI in a couple of years. Given that so much has to be there simultaneously, i. e. anticipation, restoration of the implicit-explicit balance, and communicative re-packaging (‘re-ostension’

MATHEMATICAL MODEL AND SIMULATION OF VEHICLE PLATOON OVERTAKING OTHER VEHICLE

2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Eisuke Kita ◽  
Hiroki Sakamoto
Keyword(s):  
Mathematical Model ◽  
Traffic Flow ◽  
Road Construction ◽  
The Other ◽  
Model And Simulation ◽  
Vehicle Velocity ◽  
Vehicle Platoon ◽  
And Behavior ◽  
The Mathematical Model ◽  
Near Future

A vehicle platoon is the method of grouping vehicles into platoon and driving synchronously. The vehicles in the platoon can travel safely in very small vehicle distance with the help of the mechanical and electric systems and thus, the traffic flow can be increased without any additional road construction. In this study, the interaction behavior between the vehicle platoon of three vehicles and the other vehicle is discussed. When the platoon of three vehicles overtakes the other vehicle, the vehicles in the platoon change the lane, overtake the preceding slow-travelling vehicle and changes the lane again. The vehicle velocity is controlled according to the vehicle following model (Bierley 1963, Chandler et. al. 1958, Gazis et. al. 1961, Helly 1959). The control models of vehicle velocity and behavior are defined in the mathematical model and discussed in the experiments of the robot vehicle. The results show that the model can make the platoon overtakes the other vehicle safely. In the near future, the model should be improved in order to enhance the safety and the efficiency of the vehicle platoon.

scholarly journals Analysis of Some Approaches to Modeling Nonlinear Dynamical Systems Using Polynomial Operators

2021 ◽  
Vol 43 (5) ◽  
pp. 3-20
Author(s):  
A.F. Verlan ◽  
◽  
L.O. Mitko ◽  
O.A. Dyachuk ◽  
◽  
...  
Keyword(s):  
Dynamical Systems ◽  
Power Plants ◽  
Volterra Series ◽  
Nonlinear Dynamical Systems ◽  
Dynamic Properties ◽  
Surveillance Systems ◽  
Nonlinear Dynamical ◽  
Relevant Today ◽  
Polynomial Operators ◽  
The Mathematical Model

The problem of mathematical description of nonlinear dynamical systems remains relevant today, especially given the need to build modern surveillance systems for complex technical objects, such as power plants. The use of polynomial operators obtained with the help of shortened Volterra series to solve this problem, as practice has shown, proved to be promising, because this method allows to display in the mathematical model both nonlinear and dynamic properties of systems. For further development of the method, it is advisable to analyze diffe­rent approaches in order to build effective algorithms for obtaining and applying in the problems of monitoring the functioning of nonlinear systems.

scholarly journals A CFD Porous Materials Model to Test Soil Enriched with Nanostructured Zeolite Using ANSYS-Fluent(™)

2021 ◽  
Author(s):  
Diana Barraza-Jiménez ◽  
Sandra Iliana Torres-Herrera ◽  
Patricia Ponce Peña ◽  
Carlos Omar Ríos-Orozco ◽  
Adolfo Padilla Mendiola ◽  
...  
Keyword(s):  
Flow Behavior ◽  
Soil Health ◽  
Material Model ◽  
Ansys Fluent ◽  
Simulation Tools ◽  
Solid Mixture ◽  
Test Soil ◽  
Future Work ◽  
The Mathematical Model ◽  
Near Future

Soil health is a great concern worldwide due to the huge variety of pollutants and human activities that may cause damage. There are different ways to remediate and make a better use of soil and a choice may be using zeolite in activities like gardening, farming, environment amending, among others. In this work is proposed a model to simulate how mixing zeolite with soil may be beneficial in different ways, we are especially interested in interactions of mixed soil-zeolite with water. This model is based in different flow regimes where water interacts with two layers formed by nanostructured zeolite and soil in a vertical arrangement. The analysis is approached as a bi-layer porous material model resolved by using the mathematical model implemented in ANSYS-Fluent. Such model uses a multi-fluid granular model to describe the flow behavior of a fluid–solid mixture where all the available interphase exchange coefficient models are empirically based. Despite the great capabilities of numerical simulation tools, it is known that at present time, the literature lacks a generalized formulation specific to resolve this kind of phenomena where a porous media is analyzed. This model is developed to obtain a systematic methodology to test nanomaterials with porous features produced in our laboratory which is the next step for near future work within our research group.

scholarly journals A Comparative Analysis of Recent Identification Approaches for Discrete-Event Systems

2010 ◽  
Vol 2010 ◽  
pp. 1-21 ◽  
Author(s):  
Ana Paula Estrada-Vargas ◽  
Ernesto López-Mellado ◽  
Jean-Jacques Lesage
Keyword(s):  
Mathematical Model ◽  
Comparative Analysis ◽  
Dynamical Systems ◽  
Discrete Event Systems ◽  
Discrete Event ◽  
Event Systems ◽  
Systems Identification ◽  
Unknown System ◽  
The Mathematical Model ◽  
Inputs And Outputs

Analogous to the identification of continuous dynamical systems, identification of discrete-event systems (DESs) consists of determining the mathematical model that describes the behaviour of a given ill-known or eventually unknown system from the observation of the evolution of its inputs and outputs. First, the paper overviews identification approaches of DES found in the literature, and then it provides a comparative analysis of three recent and innovative contributions.

Improved Efficiency of Sewage Sludge Incineration by Preceding Sludge Drying

1990 ◽  
Vol 22 (12) ◽  
pp. 269-276 ◽  
Author(s):  
Heinz Brechtel ◽  
Hartmut Eipper
Keyword(s):  
Sewage Sludge ◽  
Fluidized Bed ◽  
Calorific Value ◽  
Primary Energy ◽  
Operational Experience ◽  
Special Equipment ◽  
Sludge Incineration ◽  
Technical Modifications ◽  
Sludge Drying ◽  
Near Future

Normally, mechanical dewatering of sewage sludges is not sufficient for a self-supporting combustion, even if combustion is ensured in the fluidized bed furnace. The heat balance can be compensated by firing additional fuels of higher calorific value and a preceding sludge drying using the heat, which is generated during combustion. The most favoured solution is an indirect drying in special equipment adapted to the state of the sewage sludge to be burnt. Heating surfaces and the steam transfer the thermal energy of the flue gases to the mechanically dewatered sludge. The development of malodours and pollutants in the vapours is controlled by an appropriate process flow. The process entails not only an economy of primary energy but also an increase in the furnace throughput. In Wuppertal-Buchenhofen, the fluidized bed fired sludge incineration plant has been operating for 12 years.In the near future it will be brought up to date by retrofitting such a drying system. The foreseeable effects have already been investigated and operational experience gained with other plants has been taken into account. The technical modifications, which are being considered, the operational influences expected, as well as all consequences with regard to investment and operating costs, have been outlined.

scholarly journals Phase Plane Method for the Parameter Identification of Strongly Nonlinear Systems

2001 ◽  
Vol 8 (1) ◽  
pp. 49-53
Author(s):  
Tang Jiashi
Keyword(s):  
Nonlinear Systems ◽  
Parameter Identification ◽  
Phase Plane ◽  
Plane Method ◽  
System Parameters ◽  
Strongly Nonlinear ◽  
Optimum Technique ◽  
Phase Plane Method ◽  
The Mathematical Model ◽  
Trajectory Equation

A phase plane method is presented for the parameter identification of strongly nonlinear systems. The phase trajectory equation is taken as the mathematical model and the system parameters are identified by using the optimum technique. The method can be applied to conservative and non-conservative systems. The value ranges of the parameters are not limited. All examples simulated by computer show that the efficiency and accuracy of this approach are very good.

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