External Effects in the 400-m Hurdles Race

2010 ◽  
Vol 26 (2) ◽  
pp. 171-179 ◽  
Author(s):  
Mike D. Quinn
Keyword(s):  
Differential Equation ◽  
Mathematical Model ◽  
Wind Speed ◽  
Equation Of Motion ◽  
Propulsive Force ◽  
External Effects ◽  
Men And Women ◽  
Wind Resistance ◽  
Race Performance ◽  
Aerobic And Anaerobic

A mathematical model based on a differential equation of motion is used to simulate the 400-m hurdles race for men and women. The model takes into account the hurdler’s stride pattern, the hurdle clearance, and aerobic and anaerobic components of the propulsive force of the athlete, as well as the effects of wind resistance, altitude of the venue, and curvature of the track. The model is used to predict the effect on race times of different wind conditions and altitudes. The effect on race performance of the lane allocation and the efficiency of the hurdle clearance is also predicted. The most favorable wind conditions are shown to be a wind speed no greater than 2 m/s assisting the athlete in the back straight and around the second bend. The outside lane (lane 8) is shown to be considerably faster than the favored center lanes. In windless conditions, the advantage can be as much as 0.15 s for men and 0.12 s for women. It is shown that these values are greatly affected by the wind conditions.

scholarly journals Pacing strategy in horse racing

2020 ◽  
Author(s):  
Quentin Mercier ◽  
Amandine Aftalion
Keyword(s):  
Mathematical Model ◽  
Motor Control ◽  
Oxygen Uptake ◽  
Horse Racing ◽  
Propulsive Force ◽  
Velocity Data ◽  
Pacing Strategy ◽  
Fixed Distance ◽  
Aerobic And Anaerobic

AbstractThanks to velocity data on races in Chantilly (France), we set a mathematical model which provides the optimal pacing strategy for horses on a fixed distance. It relies on mechanics, energetics (both aerobic and anaerobic) and motor control. We identify the parameters useful for the model from the data. Then it allows to understand the velocity, the oxygen uptake evolution in a race, as well as the energy or the propulsive force and predict the changes in pacing according to the properties (altitude and bending) of the track.

Attachment energy saving gripping device for chokerless timber skidding when thinning

10.12737/4537 ◽  
2014 ◽  
Vol 4 (2) ◽  
pp. 223-228
Author(s):  
Латышева ◽  
M. Latysheva ◽  
Зеликов ◽  
Vladimir Zelikov ◽  
Посметьев ◽  
...  
Keyword(s):  
Differential Equation ◽  
Mathematical Model ◽  
Energy Saving ◽  
Hydraulic Cylinder ◽  
Equation Of Motion ◽  
The Mathematical Model ◽  
Attachment Energy

Hydrokinetic diagram of the device for chokerless skidding is presented. Chokerless device for logging includes a frame, capture with two jaws and hydraulic cylinder of jaw gripping attached to the hinged system of tractor, linked via a double-hinged capture unit to one end of the bell crank, and between the second end of the bell crank and the frame there is pivotally mounted hydraulic cylinder for additional amortization of oscillations of grapple. The mathematical model of the process of logging trees is made. It includes a differential equation of whips pack and differential equation of motion of the accumulator piston.

The Effects of Wind and Altitude in the 200-m Sprint

2003 ◽  
Vol 19 (1) ◽  
pp. 49-59 ◽  
Author(s):  
Mike D. Quinn
Keyword(s):  
Mathematical Model ◽  
Sea Level ◽  
Wind Direction ◽  
Combined Effect ◽  
Ranking List ◽  
Men And Women ◽  
Wind Resistance ◽  
Wind Speeds ◽  
Air Density ◽  
Component Velocity

A mathematical model is used to determine the effect of wind resistance and altitude on 200-m race times. The model is used to simulate the effect of different wind speeds, wind directions, and lane allocation in the 200-m sprint. For the 200-m event there is a single wind gauge recording only the wind’s component velocity in the straight, and not the wind direction. For record purposes the wind reading should not exceed 2 m/s. It is evident that for the same official wind reading, an athlete may face vastly different conditions. The model estimates that for the same wind reading, the prevailing conditions can produce a time difference of as much as 0.5 s. Results indicate that many legal performances in the 200-m are currently ruled out for record purposes. Some performances which are officially wind-assisted have in fact been hindered by an overall head wind when it is averaged throughout the race. Conversely, some performances which are run into a head wind in the straight have benefited from an overall tail wind. We estimate that, on average, for a 2-m/s wind blowing down the straight, the 200-m runner benefits from an overall tail wind of only 0.95 m/s. The lower air density at an altitude of 1,500 meters produces an advantage of 0.11 s in the 200-m, which equates to a 2-m/s tail wind at sea level blowing directly down the straight. Correction estimates are provided for the combined effect of both wind and altitude in 200-m races. A new all-time world top five ranking list for men and women is produced for the 200-m event, corrected for wind and altitude effects.

A Mathematical Model on Social Integration Explaining Global Suicide Rate Among Men and Women

2014 ◽  
Vol 2 (1) ◽  
pp. 49-54
Author(s):  
Mark Borres ◽  
◽  
Jergen Orias ◽  
Alvin Mercado ◽  
◽  
...  
Keyword(s):  
Mathematical Model ◽  
Social Integration ◽  
Suicide Rate ◽  
Men And Women

scholarly journals Analysis of Performance of the Wind-Driven Pulverizing Aerator Based on Average Wind Speeds in the Conditions of Góreckie Lake

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2796
Author(s):  
Andrzej Osuch ◽  
Ewa Osuch ◽  
Stanisław Podsiadłowski ◽  
Piotr Rybacki
Keyword(s):  
Mathematical Model ◽  
Wind Speed ◽  
Water Pump ◽  
Average Wind Speed ◽  
Flow Rates ◽  
Wind Speeds ◽  
Average Wind ◽  
Flow Through ◽  
Analysis Of Performance ◽  
Research Period

In the introduction to this paper, the characteristics of Góreckie lake and the construction and operation of the wind-driven pulverizing aerator are presented. The purpose of this manuscript is to determine the efficiency of the pulverizing aerator unit in the windy conditions of Góreckie Lake. The efficiency of the pulverization aerator depends on the wind conditions at the lake. It was necessary to conduct thorough research to determine the efficiency of water flow through the pulverization segment (water pump). It was necessary to determine the rotational speed of the paddle wheel, which depended on the average wind speed. Throughout the research period, measurements of hourly average wind speed were carried out. It was possible to determine the efficiency of the machine by developing a dedicated mathematical model. The latest method was used in the research, consisting of determining the theoretical volumetric flow rates of water in the pulverizing aerator unit, based on average hourly wind speeds. Pulverization efficiency under the conditions of Góreckie Lake was determined based on 6600 average wind speeds for spring, summer and autumn, 2018. Based on the model, the theoretical efficiency of the machine was calculated, which, under the conditions of Góreckie Lake, amounted to 75,000 m3 per year.

The Numerical Methods of Peridynamics Theory Used in Failure Analysis of Materials

2014 ◽  
Vol 1030-1032 ◽  
pp. 223-227
Author(s):  
Lin Fan ◽  
Song Rong Qian ◽  
Teng Fei Ma
Keyword(s):  
Differential Equation ◽  
Integral Equation ◽  
Numerical Integration ◽  
Integration Method ◽  
Equation Of Motion ◽  
Numerical Integration Method ◽  
Volume Integral ◽  
Volume Integral Equation ◽  
Method Of Molecular Dynamics ◽  
Classic Theory

In order to analysis the force situation of the material which is discontinuity,we can used the new theory called peridynamics to slove it.Peridynamics theory is a new method of molecular dynamics that develops very quickly.Peridynamics theory used the volume integral equation to constructed the model,used the volume integral equation to calculated the PD force in the horizon.So It doesn’t need to assumed the material’s continuity which must assumed that use partial differential equation to formulates the equation of motion. Destruction and the expend of crack which have been included in the peridynamics’ equation of motion.Do not need other additional conditions.In this paper,we introduce the peridynamics theory modeling method and introduce the relations between peridynamics and classic theory of mechanics.We also introduce the numerical integration method of peridynamics.Finally implementation the numerical integration in prototype microelastic brittle material.Through these work to show the advantage of peridynamics to analysis the force situation of the material.

A Meshless Method for Solving the Mathematical Model Associated the Leakage Problem in Gas Pipeline

2014 ◽  
Vol 986-987 ◽  
pp. 1418-1421
Author(s):  
Jun Shan Li
Keyword(s):  
Differential Equation ◽  
Mathematical Model ◽  
Partial Differential Equation ◽  
Inverse Problem ◽  
Basis Function ◽  
Meshless Method ◽  
Numerical Solutions ◽  
Basis Functions ◽  
Gas Pipeline ◽  
The Mathematical Model

In this paper, we propose a meshless method for solving the mathematical model concerning the leakage problem when the pressure is tested in the gas pipeline. The method of radial basis function (RBF) can be used for solving partial differential equation by writing the solution in the form of linear combination of radius basis functions, that is, when integrating the definite conditions, one can find the combination coefficients and then the numerical solution. The leak problem is a kind of inverse problem that is focused by many engineers or mathematical researchers. The strength of the leak can find easily by the additional conditions and the numerical solutions.

A MATHEMATICAL MODEL OF ANEURYSM OF CIRCLE OF WILLIS

1995 ◽  
Vol 03 (03) ◽  
pp. 653-659 ◽  
Author(s):  
J. J. NIETO ◽  
A. TORRES
Keyword(s):  
Differential Equation ◽  
Mathematical Model ◽  
Ordinary Differential Equation ◽  
Blood Flow ◽  
Nonlinear Analysis ◽  
Existence Of Solutions ◽  
Circle Of Willis ◽  
Second Order ◽  
Qualitative Properties

We introduce a new mathematical model of aneurysm of the circle of Willis. It is an ordinary differential equation of second order that regulates the velocity of blood flow inside the aneurysm. By using some recent methods of nonlinear analysis, we prove the existence of solutions with some qualitative properties that give information on the causes of rupture of the aneurysm.

scholarly journals Relationship analysis of wall transmittance and wind speed with numerical method

2019 ◽  
Vol 10 (2) ◽  
pp. 207-212
Author(s):  
F. Szodrai
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Natural Convection ◽  
Wind Speed ◽  
Building Structures ◽  
Cold Side ◽  
External Effects ◽  
Dynamic Simulations ◽  
Relationship Analysis ◽  
Two Sides

In heat transfer calculations, transmittance values are often used as a constant in practice. With the spread of dynamic simulations, it opens an opportunity to study the sensitivity of the external effects (e.g., wind speed) on buildings. With the proper amount of result, adequate simplifications can be made to reduce the duration of the simulations. In this paper several steady sate simulations were carried out by Ansys 19.1. Academic version. In the examined cases three building structures were examined with different thermal resistances. Average initial air temperature difference was applied on the two sides of the structures, at the cold side the wind speed was varied, while at the warm side natural convection was present. The surface temperatures and the heat flux were monitored and the transmittances were calculated as a result.

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