4,195 research outputs found
Determining, scoring and presenting successful performance in professional rugby league
Performance indicators allow for the objective quantification of performance (Vogelbein, Nopp & Hokelmann, 2014). However, limited PI research for professional rugby league exists, with just one paper published (Woods, Sinclair and Robertson, 2017) although this was conducted on teams from the Australian elite competition, the NRL, with no similar attempts for Europe’s Super League competition. Therefore, this thesis aimed to identify robust indicators of success for professional rugby league teams in super league, which would subsequently allow performances to be scored and assessed graphically through performance profiles.
Data from all 27 rounds of the 2012, 2013 and 2014 European Super League seasons were collected by Opta, amounting to 567 matches. Data for 45 action variables was extracted from spreadsheets using Visual Basic for Applications in Microsoft Excel (Excel, v2013, Microsoft Inc., Redmond, USA). To enable clear comparisons between winning and losing teams, draws (n=22) were excluded.
Study 1 assessed twenty-four relative variables (home value minus away) using backwards logistic (match outcome) and linear (points difference) regression models alongside exhaustive Chi-Square Automatic Interaction Detection (CHAID) decision trees to identify performance indicators (PIs) and key performance indicators (KPIs). However, some variables which were thought to be important (as identified by previous literature) were removed from the analysis as they did not contribute to the model’s predictive ability as much as others thus calling into question the appropriateness of stepwise methods. Furthermore, unusual results were evident which lead to the conclusion that a suitable dimension reduction technique could be more appropriate to analyse large datasets with multiple variables that could be related to each other.
Study 2 utilised principal component analysis to reduce 45 action variables into 10 orthogonal principle components. These components were analysed using backwards and enter methods in logistic and linear regression models alongside CHAID decision trees. This method provided a relevant guide on how teams could improve their performance by improving a collection of variables as opposed to traditional methods which described individual variables. Furthermore, the use of stepwise methods was argued to be less appropriate for sporting performances as some principal components that could relate to success may be removed. Results from both regression models indicated large variations on confidence intervals for beta coefficients and odds ratios, suggesting that the variation of a set of values are more representative of the data analysed, when assessing multiple teams. Therefore, idiographic assessments of performances were suggested to provide relevant information for practitioners, which can be lost through traditional nomothetic approaches, as evidenced in this study.
Study 3 utilised the principle component scores to create idiographic performance profiles, according to match venue and match closeness. In addition, a case study was produced assessing two teams’ previous performances, prior to an upcoming game, providing a practical example of how practitioners could utilise this information in their respective environments. Although large variations were evident on profiles, it was suggested that team performances may never stabilise due to the unpredictability of complex sports involving multiple players like rugby league. However it was clear that idiographic profiles provided meaningful and informative assessments of performance which were arguably more relevant for practitioners compared to traditional nomothetic methods.
Overall, this thesis facilitated a greater understanding of how rugby league teams perform in Super League, through the use of practical and relevant methodologies that can be utilised by practitioners and coaches who are constantly striving to improve sporting performance. Future research must consider the ‘theory-practice’ gap identified by McKenzie and Cushion (2013) in order to provide simple and relevant answers that practitioners require, which seems to be a principle that has remained elusive thus far
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China’s rise in a liberal world order in transition – introduction to the FORUM
In a time of great uncertainty about the future and resilience of the liberal world order this Forum focuses on China’s rise and interplay with the foundations of that liberal order. The key question is the extent to and variegated ways in which China - with its (re)ascendance to power and potential global leadership – is adapting to and perhaps even strengthening liberal institutions and rules of the game, confronting them, or developing alternative paths. In this introduction to the Forum we advance three key points based on the contributions. First, contrasting the orthodox binary scenarios of either inevitable conflict or co-optation offered in the mainstream IR debate, the Forum highlights the possibility of a third scenario of China’s interplay with the liberal world and its key actors, institutions, and rules. A hybrid and variegated scenario that entails both conflict and adaptation, differently entangled in different issue areas. Second, it stresses the need to conceptualize and empirically comprise the essentially interlinked nature of domestic state-society models and the global political economy. Third, we argue for a perspective that incorporates underlying economic and social structures and the power relations embedded therein
Process Parameters Optimization of Resistance Spot Welding of Galvanized Steel Using Taguchi Method
Spot welding is a resistance welding process for joining metal sheets by directly applying opposite forces with pointed tips. The current and the heat generation are localized by the form of electrode. The amount of heat produced is a function of current, time and resistance between the work pieces. The present work attempts experimental investigations to study influence of important process parameters of resistance spot welding on weld strength, current and cycle time are varied at three different levels for different thickness and manufactured specimens are tested for weld strength.. Experiment have been conducted as per Taguchi method and fixed the levels for the parameters Analysis of variance (ANOVA) and F-test has been used for determining most significant parameters affecting the spot weld parameters
Prediction of performance parameters in Wire EDM of HcHcr steel using Artificial Neural Network
Electrical discharge machining has been extensively used for cutting intricate contours or delicate cavities that would be difficult to produce with a conventional machining methods or tools. Wire EDM is in use for a long time for cutting punches and dies, shaped pockets and other complex shaped parts. Performance of the process is mainly depends on many parameters used during process. Machining input parameters provided by the machine tool builder cannot always meet the operator’s requirements. So, artificial neural network is introduced as an efficient approach to predict the values of performance parameters. In the present research, experimental investigations have been conducted to develop predictive models for the effect of input parameters on the responses such as Material Removal Rate, surface finish and kerf width. Material tested was HcHcr steel material. Molybdenum wires of diameters 0.18 mm were used for the WEDM machine. A feed forward back propagation artificial neural network (ANN) is used to model the influence of current, pulse-ON and pulse-OFF time on material removal rate, kerf width & surface roughness. Multilayer perception model has been constructed with feed forward back propagation algorithm using peak current, pulse-ON and pulse-OFF time as input parameters and MRR and surface roughness and kerf width as the output parameters. The predicted results based on the ANN model are found to be in very close agreement with the unexposed experimental data set. The modeling results confirm the feasibility of the ANN and its good correlation with the experimental results
A BeppoSAX observation of the supersoft source 1E 0035.4-7230
Results from a 37,000 s BeppoSAX Low-Energy Concentrator Spectrometer (LECS)
observation of the supersoft source SMC 13 (=1E 0035.4-7230) in the Small
Magellanic Cloud are reported. The BeppoSAX spectrum is fitted either with a
blackbody spectrum with an effective temperature kT = 26-58 eV, an LTE white
dwarf atmosphere spectrum with kT = 35-50 eV, or a non-LTE white dwarf
atmosphere spectrum with kT = 25-32 eV. The bolometric luminosity is < 8 10^37
erg s-1 and < 3 10^37 erg s^-1 for the LTE and the non-LTE spectrum. We also
applied a spectral fit to combined spectra obtained with BeppoSAX LECS and with
ROSAT PSPC. The kT derived for the non-LTE spectrum is 27-29 eV, the bolometric
luminosity is 1.1-1.2 10^37 erg s^-1. We can exclude any spectrally hard
component with a luminosity > 2 10^35 erg s^-1 (for a bremmstrahlung with a
temperature of 0.5 keV) at a distance of 60 kpc. The LTE temperature is
therefore in the range 5.5+/-0.2 10^5 K and the non-LTE temperature in the
range 3.25+/-0.16 10^5 K. Assuming the source is on the stability line for
atmospheric nuclear burning, we constrain the white dwarf mass from the LTE and
the non-LTE fit to ~1.1 M-solar and ~0.9 M-solar respectively. However, the
temperature and luminosity derived with the non-LTE model for 1E 0035.4-7230 is
consistent with a lower mass M~0.6-0.7 M-solar white dwarf as predicted by Sion
and Starrfield (1994). At the moment, neither of these two alternatives for the
white dwarf mass can be excluded.Comment: 6 pages, accepted by A&A March 30th 199
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