scholarly journals The (non) determinants of Olympic success

2021 ◽  
pp. 152700252199283
Author(s):  
Johan Rewilak
Keyword(s):  
Population Size ◽  
Athletic Performance ◽  
Host Effect ◽  
The Impact ◽  
Tobit Estimator

This paper empirically examines the determinants of Summer Olympic success during the period 1996-2016. By modifying the panel Tobit estimator using the Mundlak transform, the results find that population size and the host effect are the only statistically significant determinants of Olympic attainment. We also show that participating in front of a home crowd will stimulate athletic performance equally for each gender, but the impact of population differs between the sexes. These findings are confirmed using a hurdle estimator. This relaxes the assumption that the factors determining Olympic success are the same as those that influence the quantity of success.

scholarly journals The Impact of Sports on Athletic Performance

2016 ◽  
Vol 10 (6) ◽  
pp. 21
Author(s):  
Amir Torkashvand
Keyword(s):  
Athletic Performance ◽  
Applied Research ◽  
Demographic Information ◽  
Alpha Coefficient ◽  
Strategic Performance ◽  
The Third ◽  
Spss Software ◽  
High Level ◽  
Descriptive Survey ◽  
The Impact

This study seeks to influence environment sports on the performance of athletes. Applied research is a descriptive survey. The population consisted of high-level of athletes in martial disciplines in Tehran (3 sports gym) were estimated at around 158 people. 113 athletes have been invited to respond to the questionnaire that they use randomly chosen sample of the population by Cochran formula. A questionnaire was used for data collection. The questionnaire consists of 3 parts. The first part included demographic information and the second part of the questionnaire contains 12 questions, including questions of appearance and the third part is consist of the standard questionnaire strategic performance of Thomas. Relaiability of questionnaire is achived with experts and stability of it was 0,966 by using of Cronbach's alpha coefficient in e SPSS software. The results show that the apparent and qualitative factors are directly affecting the performance of athletes.

scholarly journals Acute Physiological and Thermoregulatory Responses to Extended Interval Training in Endurance Runners: Influence of Athletic Performance and Age

2015 ◽  
Vol 49 (1) ◽  
pp. 209-217 ◽  
Author(s):  
Felipe García-Pinillos ◽  
Víctor Manuel Soto-Hermoso ◽  
Pedro Ángel Latorre-Román
Keyword(s):  
Cluster Analysis ◽  
Athletic Performance ◽  
Repeated Measures ◽  
Perceived Exertion ◽  
Interval Training ◽  
Tympanic Temperature ◽  
Physiological Level ◽  
Thermoregulatory Responses ◽  
Endurance Runners ◽  
The Impact

Abstract This study aimed to describe the acute impact of extended interval training (EIT) on physiological and thermoregulatory levels, as well as to determine the influence of athletic performance and age effect on the aforementioned response in endurance runners. Thirty-one experienced recreational male endurance runners voluntarily participated in this study. Subjects performed EIT on an outdoor running track, which consisted of 12 runs of 400 m. The rate of perceived exertion, physiological response through the peak and recovery heart rate, blood lactate, and thermoregulatory response through tympanic temperature, were controlled. A repeated measures analysis revealed significant differences throughout EIT in examined variables. Cluster analysis grouped according to the average performance in 400 m runs led to distinguish between athletes with a higher and lower sports level. Cluster analysis was also performed according to age, obtaining an older group and a younger group. The one-way analysis of variance between groups revealed no significant differences (p≥0.05) in the response to EIT. The results provide a detailed description of physiological and thermoregulatory responses to EIT in experienced endurance runners. This allows a better understanding of the impact of a common training stimulus on the physiological level inducing greater accuracy in the training prescription. Moreover, despite the differences in athletic performance or age, the acute physiological and thermoregulatory responses in endurance runners were similar, as long as EIT was performed at similar relative intensity.

scholarly journals Choosing Mutation and Crossover Ratios for Genetic Algorithms—A Review with a New Dynamic Approach

Information ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 390 ◽  
Author(s):  
Ahmad Hassanat ◽  
Khalid Almohammadi ◽  
Esra’a Alkafaween ◽  
Eman Abunawas ◽  
Awni Hammouri ◽  
...  
Keyword(s):  
Population Size ◽  
Optimization Problems ◽  
Large Population ◽  
Small Population ◽  
Mutation Rates ◽  
Mutation Operators ◽  
Tuning Methods ◽  
Two Parameters ◽  
The Impact ◽  
Crossover And Mutation

Genetic algorithm (GA) is an artificial intelligence search method that uses the process of evolution and natural selection theory and is under the umbrella of evolutionary computing algorithm. It is an efficient tool for solving optimization problems. Integration among (GA) parameters is vital for successful (GA) search. Such parameters include mutation and crossover rates in addition to population that are important issues in (GA). However, each operator of GA has a special and different influence. The impact of these factors is influenced by their probabilities; it is difficult to predefine specific ratios for each parameter, particularly, mutation and crossover operators. This paper reviews various methods for choosing mutation and crossover ratios in GAs. Next, we define new deterministic control approaches for crossover and mutation rates, namely Dynamic Decreasing of high mutation ratio/dynamic increasing of low crossover ratio (DHM/ILC), and Dynamic Increasing of Low Mutation/Dynamic Decreasing of High Crossover (ILM/DHC). The dynamic nature of the proposed methods allows the ratios of both crossover and mutation operators to be changed linearly during the search progress, where (DHM/ILC) starts with 100% ratio for mutations, and 0% for crossovers. Both mutation and crossover ratios start to decrease and increase, respectively. By the end of the search process, the ratios will be 0% for mutations and 100% for crossovers. (ILM/DHC) worked the same but the other way around. The proposed approach was compared with two parameters tuning methods (predefined), namely fifty-fifty crossover/mutation ratios, and the most common approach that uses static ratios such as (0.03) mutation rates and (0.9) crossover rates. The experiments were conducted on ten Traveling Salesman Problems (TSP). The experiments showed the effectiveness of the proposed (DHM/ILC) when dealing with small population size, while the proposed (ILM/DHC) was found to be more effective when using large population size. In fact, both proposed dynamic methods outperformed the predefined methods compared in most cases tested.

scholarly journals Assessment of Equity in Access to Percutaneous Coronary Intervention (PCI) Centres in Poland

Healthcare ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 71 ◽  
Author(s):  
Justyna Rój ◽  
Maciej Jankowiak
Keyword(s):  
Percutaneous Coronary Intervention ◽  
Population Size ◽  
Gini Coefficient ◽  
Coronary Intervention ◽  
Invasive Procedures ◽  
Invasive Treatment ◽  
The Gini Coefficient ◽  
Invasive Cardiology ◽  
Percutaneous Coronary ◽  
The Impact

The purpose of this study is to analyse the disparities in the distribution of percutaneous coronary intervention (PCI) centres in Poland and the impact of eventual inequities on access to the invasive treatment of acute myocardial infarctions (AMI). To examine the distribution of PCI centres against population size and geographic size in Poland, the Gini coefficient calculated based on the Lorenz Curve was engaged. In addition, the regression function was employed to estimate the impact of distribution of PCI centres on access to invasive procedures (coronarographies and primary percutaneous coronary intervention). Data were collected from the public statistical system and Polish National Health Fund database for the year 2018. The relation and the level of equity was measured based on the aggregated data at a district (voivodeship) level. The results of the Gini coefficient analysis show that the distribution of invasive cardiology units measured against population size is more equitable than when measured against geographic size. In addition, the regression analysis shows the moderate size of the positive correlation between number of PCI centres per 100,000 population and the number of all categories of the invasive treatment of AMI per 100,000 population, and the lack of similar correlation in case of the number of PCI centres expressed per 1000 km2, which could be evidence of an insufficiency of PCI centres in areas where the concentration of PCI centres per 100,000 population is lower. The main implication for policy makers that results from this research is the need for a correction of PCI centres distribution per 100,000 inhabitants to ensure better access to invasive procedures.

scholarly journals Utilizing the National Basketball Association’s COVID-19 restart “bubble” to uncover the impact of travel and circadian disruption on athletic performance

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Andrew W. McHill ◽  
Evan D. Chinoy
Keyword(s):  
Athletic Performance ◽  
Natural Experiment ◽  
Circadian Disruption ◽  
Multiple Time ◽  
General Effect ◽  
Professional Basketball ◽  
Home Team ◽  
Winning Percentage ◽  
Time Zones ◽  
The Impact

AbstractOn March 11th, 2020, the National Basketball Association (NBA) paused its season after ~ 64 games due to the Coronavirus 2019 (COVID-19) outbreak, only to resume ~ 5 months later with the top 22 teams isolated together (known as the “bubble”) in Orlando, Florida to play eight games each as an end to the regular season. This restart, with no new travel by teams, provided a natural experiment whereby the impact of travel and home-court advantage could be systematically examined. We show here that in the pre-COVID-19 regular season, traveling across time zones reduces winning percentage, team shooting accuracy, and turnover percentage, whereas traveling in general reduces offensive rebounding and increases the number of points the opposing (home) team scores. Moreover, we demonstrate that competition in a scenario where no teams travel (restart bubble) reduces the typical effects of travel and home-court advantage on winning percentage, shooting accuracy, and rebounding. Thus, home-court advantage in professional basketball appears to be linked with the away team’s impaired shooting accuracy (i.e., movement precision) and rebounding, which may be separately influenced by either circadian disruption or the general effect of travel, as these differences manifest differently when teams travel within or across multiple time zones.

Demographic Impact on Environment - A Case Study Focussing on CO2 Emission in China

1998 ◽  
Vol 10 (2) ◽  
pp. 81-87
Author(s):  
Kenji Hayashi ◽  
Jianqun Gao
Keyword(s):  
Population Size ◽  
Urban Areas ◽  
Fossil Fuels ◽  
Energy Transition ◽  
Population Increase ◽  
High Fertility ◽  
Economic Activities ◽  
The North ◽  
Per Capita ◽  
The Impact

Carbon dioxide (CO2) emission derived from economic activities results primarily from the fossil fuels consumed. The variety of fossil fuels used, the degree of efficient consumption of energy, economic growth and national population size determine the total amount of CO2 emission in a country. Considering its population size as well as its potential for economic development, China is expected to play a key role in the global warming issue in concert with other industrialized Asian countries, including Japan. In the present study, the impact of population increase on total CO2 emission in China during the period 1982-1990 was analyzed. During the study period, population increase and CO2 emission per capita were 21 per cent and 70 per cent, respectively. In terms of population increase by region, some provinces in the inland areas and megacities, like Shanghai and Beijing, contributed the highest figures. To cope with high fertility in the inland areas as well as massive population inflow into the urban areas simultaneously, increasing the number of medium-sized cities to be located in the inland areas could be a solution. For CO2 emission per capita, the figures for the North-Eastcrn provinces and South-Eastern provinces along the coast are remarkable. The estimate of total emission of CO2 by 2010 is 1.6 million tons, a 74 per cent increase from 1992. Energy transition is the key to the stabilization of CO2 emission in China.

scholarly journals The Impact of Circadian Misalignment on Athletic Performance in Professional Football Players

SLEEP ◽  
2013 ◽  
Vol 36 (12) ◽  
pp. 1999-2001 ◽  
Author(s):  
Roger S. Smith ◽  
Bradley Efron ◽  
Cheri D. Mah ◽  
Atul Malhotra
Keyword(s):  
Athletic Performance ◽  
Football Players ◽  
Professional Football ◽  
Circadian Misalignment ◽  
The Impact
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