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A Comparison of a Smartphone App with Other GPS Tracking Type Devices Employed in Football
Peter Tierney(Peter Tierney ),Neil Clarke(Neil Clarke ) 사피엔시아 2019 Exercise Medicine Vol.3 No.-
Objectives: The purpose of this study was to evaluate the use of a smartphone application in comparison against current GPS tracking type devices that are used to track players during football training and match play. Football involves repeated multi directional movements of the whole body at varying speeds and varying distances from walking to high speed running. Therefore, to evaluate validity and reliability of smartphones and elite tracker devices both were assessed and compared against each other for common metrics employed in football player activity tracking. Methods: These being, walking ≤6km/hr, jogging 6.1-12km/hr, running 12.1-18km/hr, high speed running ≥18km/hr, total distance (m), max speed (km/hr) and positional heat map. Post analysis values obtained showed that there were no significant differences between smartphones employed in the study p<0.001 95%. Furthermore, values with both the smartphone app and the GPS tracking device showed a high degree of correlation (r = 0.94-0.99, p<0.001). Results: The results of this study show that a smartphone application can be used for capturing data in football environments. However, caution should be taken over what data to collect and use. Conclusions: That said, having the ability to easily capture such data with a smartphone can provide a practical and inexpensive tool to measure and easily visualise physical activity in football participation.
R: AN OVERVIEW AND SOME CURRENT DIRECTIONS
Tierney, Luke The Korean Statistical Society 2007 Journal of the Korean Statistical Society Vol.36 No.1
R is an open source language for statistical computing and graphics based on the ACM software award-winning S language. R is widely used for data analysis and has become a major vehicle for making available new statistical methodology. This paper presents an overview of the design philosophy and the development model for R, reviews the basic capabilities of the system, and outlines some current projects that will influence future developments of R.
R: An Overview and Some Current Directions
Luke Tierney 한국통계학회 2007 Journal of the Korean Statistical Society Vol.36 No.1
R is an open source language for statistical computing and graphics basedon the ACM software award-winning S language. R is widely used for dataanalysis and has become a major vehicle for making available new statisticalmethodology. This paper presents an overview of the design philosophy andthe development model for R, reviews the basic capabilities of the system,and outlines some current projects that will inuence future developmentsof R.AMS 2000 subject classications.Primary 68N15; Secondary 62-07.Keywords.Computer language, graphics, isosurfaces, parallel computation, R, statisticalcomputing.1. IntroductionR is a language for statistical computing and graphics. R, along with S-plus,is a member of the S language family originally developed by John Chambers andcolleagues at Bell Laboratories (Becker and Chambers, 1984; Beckeret al., 1988;Chambers, 1998). In 1998 the Association for Computing Machinery presentedits prestigious Software System Award to John Chambers for his development ofthe S system. In recent years the S language family, and R in particular, havebecome the de facto standard for computing in statistical research. Many booksdescribing R and S are now available; two examples are Dalgaard (2004) andVenables and Ripley (2002).R can viewed as a dierent implementation or as a dialect of S the language.While there are some important dierences between R and S-plus, some of whichare discussed in Section 6.1, much code written for S-plus runs unaltered underR. In recent years R has become a major vehicle for making available new sta-tistical methodology. Articles proposing new methods that also make availableReceived October 2006; accepted November 2006.†This research supported in part by National Sciance Foundation Grant DMS-0604593.
The Bounce-Back Effect: Checkmating Competitors with the Cold Hand
Nodir Adilov,Heather L.R. Tierney,Jayme V. Gerring,Tao Yu 사람과세계경영학회 2022 Global Business and Finance Review Vol.27 No.6
Purpose: The paper investigates the effect of winning performance streaks (the hot hand) and losing performance streaks (the cold hand) on future performance. Performance streaks have many implications in business settings, such as selecting stocks, hedge fund performance, employee performance, introducing new products, and business strategy. Design/methodology/approach: The paper empirically analyzes the effects of performance steaks. It uses data from world blitz chess championships. Findings: Contrary to some studies in competitive sports, the empirical analysis supports neither the hot hand nor the cold hand hypothesis. Instead, a new effect is discovered; performance increases following a loss. We term this effect to be the bounce-back effect. Research limitation/implications: Future research may conduct field experiments to investigate which business environments are likely to generate this effect. Similar to other studies on performance streaks, the analysis does not control for motivation. Future research may also analyze the role of motivation for performance. Originality/value: The paper identifies a new effect previously not investigated in the literature. In addition, the paper contributes to this literature by looking into competitive blitz chess, where psychological factors are more important than physiological factors. If the bounce-back effect holds more generally in other settings, it might have implications for predicting the performance of employees in competitive business environments.