scholarly journals Predictive models of the 2015 Rugby World Cup: accuracy and application

2016 ◽  
Vol 15 (1) ◽  
pp. 37-58 ◽  
Author(s):  
P. O’Donoghue ◽  
D. Ball ◽  
J. Eustace ◽  
B. McFarlan ◽  
M. Nisotaki

Abstract The current investigation compared 12 models of outcomes of international rugby union matches and then used the most accurate model to investigate performances within the 2015 Rugby World Cup. The underlying linear regression models were used within a simulation package that introduced random variability about performance evidenced by the residual distribution of the regression analyses. Each model was used within 10,000 simulations of the 2015 Rugby World Cup from which match outcome and team progression statistics were recorded. The most accurate model with respect to the actual 2015 tournament was developed using data from all seven previous tournaments rather than restricting cases to the most recent three tournaments. The model was more accurate when the data used violated the assumptions of linear regression rather than transforming variables to satisfy the assumptions. The model included World ranking points as a predictor variable and was more accurate than corresponding models that represented relative home advantage as well. The most accurate model used separate models for the pool and knockout stage matches although the 9 models that separating these match types were less accurate on average than when the two match types were considered together. This model was used to investigate properties of the 2015 Rugby World Cup. The tournament disadvantaged three teams in the World’s top 5 who were drawn in the same pool. Teams ranked in the World’s top 7 did not perform as well as predicted while teams ranked 16th and below performed better than predicted suggesting that the strength in depth in international rugby union is increasing. There was a small effect of having additional recovery days from the previous match compared to the opponents which was worth 4.1 points. The information produced by this research should be considered by those design tournaments such as the Rugby World Cup.

2013 ◽  
Vol 12 (2) ◽  
pp. 149 ◽  
Author(s):  
Julyanti S Malensang ◽  
Hanny Komalig ◽  
Djoni Hatidja

PENGEMBANGAN MODEL REGRESI POLINOMIAL BERGANDA PADA KASUS DATA PEMASARANABSTRAK Regresi polinomial merupakan regresi linier berganda yang dibentuk dengan menjumlahkan pengaruh variabel prediktor (X) yang dipangkatkan secara meningkat sampai orde ke-k. Model regresi polinomial, struktur analisisnya sama dengan model regresi linier berganda. Artinya, setiap pangkat atau orde variabel prediktor (X) pada model polinomial, merupakan transformasi variabel awal dan dipandang sebagai sebuah variabel prediktor (X) baru dalam linier berganda. Model terbaik dari kelima model yang telah diuji adalah persamaan regresi model ke-5. Hal ini dapat dilihat dari nilai koefisien determinasi sebesar 99,1% dan nilai R-Sq(adj) = 98,8%, karena nilai R2 mendekati nilai yang telah diatur dan berdasarkan pengujian yang dilakukan ternyata seluruh koefisien-koefisien dari setiap variabel bebas signifikan serta ada kelengkungan yang bersifat kubik (pangkat 3) terhadap data X3 terhadap Y. Kata kunci: Pemasaran, Regresi polynomial. DEVELOPMENT OF MULTIPOLYNOMIAL REGRESSION MODEL ON MARKETING DATA CASE ABSTRACT Polynomial regression is linear regression multiple were created by summing the effect of each predictor variable (X) is raised to increase to the order of the k.  Polynomial regression model, has the same structure with linear regression models. That is, any rank or order predictor variable (X) in polynomial models, an initial variable transformation and is seen as a predictor variable (X) has the linear regression. The best model of the six models tested were equation regression model to-5.  It can be seen from the value of the coefficient of determination of 99.1% and a value of R-Sq (adj) = 98.8%, due to the value of R2 close to the value that has been set up and based on tests performed turns all the coefficients of each independent variable significantly and there are cubic curvature (rank 3) to the data X3 to Y. Keywords : Marketing, Polynomial regression.


Author(s):  
Petter Grahl Johnstad

Abstract Spiritual experiences with entheogens have usually been studied as a form of mystical experiences. However, entheogen users have also reported less intense experiences that they refer to as spiritual experiences. Using data from the Cannabis and Psychedelics User Survey, this study analyzed the characteristics of such experiences in 319 participants. It found evidence of two types of entheogenic experience that may be called spiritual. The first involved mystical-type characteristics and was predicted in multivariate linear regression models by the spirituality of the participants, operationalized as a spiritual affiliation, motivation, and practice. The second type involved characteristics representing insight, positive feelings, and improved connections to other people and to nature. This type of entheogenic experience was predicted by spiritual motivation, but not by spiritual affiliation or practices. The article discusses the implications of these findings, which may indicate competing conceptualizations of spirituality among the participants in the study.


2018 ◽  
Vol 23 (1) ◽  
pp. 60-71
Author(s):  
Wigiyanti Masodah

Offering credit is the main activity of a Bank. There are some considerations when a bank offers credit, that includes Interest Rates, Inflation, and NPL. This study aims to find out the impact of Variable Interest Rates, Inflation variables and NPL variables on credit disbursed. The object in this study is state-owned banks. The method of analysis in this study uses multiple linear regression models. The results of the study have shown that Interest Rates and NPL gave some negative impacts on the given credit. Meanwhile, Inflation variable does not have a significant effect on credit given. Keywords: Interest Rate, Inflation, NPL, offered Credit.


Author(s):  
Nykolas Mayko Maia Barbosa ◽  
João Paulo Pordeus Gomes ◽  
César Lincoln Cavalcante Mattos ◽  
Diêgo Farias Oliveira

2020 ◽  
Vol 16 (4) ◽  
pp. 543-553
Author(s):  
Luciana Y. Tomita ◽  
Andréia C. da Costa ◽  
Solange Andreoni ◽  
Luiza K.M. Oyafuso ◽  
Vânia D’Almeida ◽  
...  

Background: Folic acid fortification program has been established to prevent tube defects. However, concern has been raised among patients using anti-folate drug, i.e. psoriatic patients, a common, chronic, autoimmune inflammatory skin disease associated with obesity and smoking. Objective: To investigate dietary and circulating folate, vitamin B12 (B12) and homocysteine (hcy) in psoriatic subjects exposed to the national mandatory folic acid fortification program. Methods: Cross-sectional study using the Food Frequency Questionnaire, plasma folate, B12, hcy and psoriasis severity using the Psoriasis Area and Severity Index score. Median, interquartile ranges (IQRs) and linear regression models were conducted to investigate factors associated with plasma folate, B12 and hcy. Results: 82 (73%) mild psoriasis, 18 (16%) moderate and 12 (11%) severe psoriasis. 58% female, 61% non-white, 31% former smokers, and 20% current smokers. Median (IQRs) were 51 (40, 60) years. Only 32% reached the Estimated Average Requirement of folate intake. Folate and B12 deficiencies were observed in 9% and 6% of the blood sample respectively, but hyperhomocysteinaemia in 21%. Severity of psoriasis was negatively correlated with folate and B12 concentrations. In a multiple linear regression model, folate intake contributed positively to 14% of serum folate, and negative predictors were psoriasis severity, smoking habits and saturated fatty acid explaining 29% of circulating folate. Conclusion: Only one third reached dietary intake of folate, but deficiencies of folate and B12 were low. Psoriasis severity was negatively correlated with circulating folate and B12. Stopping smoking and a folate rich diet may be important targets for managing psoriasis.


2003 ◽  
Vol 5 (3) ◽  
pp. 363 ◽  
Author(s):  
Slamet Sugiri

The main objective of this study is to examine a hypothesis that the predictive content of normal income disaggregated into operating income and nonoperating income outperforms that of aggregated normal income in predicting future cash flow. To test the hypothesis, linear regression models are developed. The model parameters are estimated based on fifty-five manufacturing firms listed in the Jakarta Stock Exchange (JSX) up to the end of 1997.This study finds that empirical evidence supports the hypothesis. This evidence supports arguments that, in reporting income from continuing operations, multiple-step approach is preferred to single-step one.


GEOgraphia ◽  
2018 ◽  
Vol 20 (43) ◽  
pp. 124
Author(s):  
Amaury De Souza ◽  
Priscilla V Ikefuti ◽  
Ana Paula Garcia ◽  
Debora A.S Santos ◽  
Soetania Oliveira

Análise e previsão de parâmetros de qualidade do ar são tópicos importantes da pesquisa atmosférica e ambiental atual, devido ao impacto causado pela poluição do ar na saúde humana. Este estudo examina a transformação do dióxido de nitrogênio (NO2) em ozônio (O3) no ambiente urbano, usando o diagrama de séries temporais. Foram utilizados dados de concentração de poluentes ambientais e variáveis meteorológicas para prever a concentração de O3 na atmosfera. Foi testado o emprego de modelos de regressão linear múltipla como ferramenta para a predição da concentração de O3. Os resultados indicam que o valor da temperatura e a presença de NO2 influenciam na concentração de O3 em Campo Grande, capital do Estado do Mato Grosso do Sul. Palavras-chave: Ozônio. Dióxido de nitrogênio. Séries cronológicas. Regressões. ANALYSIS OF THE RELATIONSHIP BETWEEN O3, NO AND NO2 USING MULTIPLE LINEAR REGRESSION TECHNIQUES.Abstract: Analysis and prediction of air quality parameters are important topics of current atmospheric and environmental research due to the impact caused by air pollution on human health. This study examines the transformation of nitrogen dioxide (NO2) into ozone (O3) in the urban environment, using the time series diagram. Environmental pollutant concentration and meteorological variables were used to predict the O3 concentration in the atmosphere. The use of multiple linear regression models was tested as a tool to predict O3 concentration. The results indicate that the temperature value and the presence of NO2 influence the O3 concentration in Campo Grande, capital of the State of Mato Grosso do Sul.Keywords: Ozone. Nitrogen dioxide. Time series. Regressions. ANÁLISIS DE LA RELACIÓN ENTRE O3, NO Y NO2 UTILIZANDO MÚLTIPLES TÉCNICAS DE REGRESIÓN LINEAL.Resumen: Análisis y previsión de los parámetros de calidad del aire son temas importantes de la actual investigación de la atmósfera y el medio ambiente, debido al impacto de la contaminación atmosférica sobre la salud humana. Este estudio examina la transformación del dióxido de nitrógeno (NO2) en ozono (O3) en el entorno urbano, utilizando el diagrama de series de tiempo. Las concentraciones de los contaminantes ambientales de datos y variables climáticas fueron utilizadas para predecir la concentración de O3 en la atmósfera. El uso de múltiples modelos de regresión lineal como herramienta para predecir la concentración de O3 se puso a prueba. Los resultados indican que el valor de la temperatura y la presencia de NO2 influyen en la concentración de O3 en Campo Grande, capital del Estado de Mato Grosso do Sul.Palabras clave: Ozono. Dióxido de nitrógeno. Series de tiempo. Regresiones.


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