Statistical Method
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2021 ◽  
Author(s):  
Zhongwei Liu ◽  
Jonathan M. Eden ◽  
Bastien Dieppois ◽  
Matthew Blackett

Abstract In many parts of the world, wildfires have become more frequent and intense in recent decades, raising concerns about the extent to which climate change contributes to the nature of extreme fire weather occurrences. However, studies seeking to attribute fire weather extremes to climate change are hitherto relatively rare and show large disparities depending on the employed methodology. Here, an empirical-statistical method is implemented as part of a global probabilistic framework to attribute recent changes in the likelihood and magnitude of extreme fire weather. The results show that the likelihood of climate-related fire risk has increased by at least a factor of four in approximately 40% of the world’s fire-prone regions as a result of rising global temperature. In addition, a set of recent fire weather events, occurring during a recent 5-year period (2014-2018) and identified as exceptional due to the extent to which they exceed previous maxima, are, in most cases, associated with an increase likelihood resulting from rising global temperature. The study’s conclusions highlight important uncertainties and sensitivities associated with the selection of indices and metrics to represent extreme fire weather and their implications for the findings of attribution studies. Among the recommendations made for future efforts to attribute fire weather extremes is the consideration of multiple fire weather indicators and communication of their sensitivities.


2021 ◽  
Vol 162 (6) ◽  
pp. 254
Author(s):  
Herman L. Marshall ◽  
Yang Chen ◽  
Jeremy J. Drake ◽  
Matteo Guainazzi ◽  
Vinay L. Kashyap ◽  
...  

Abstract We describe a process for cross-calibrating the effective areas of X-ray telescopes that observe common targets. The targets are not assumed to be “standard candles” in the classic sense, in that we assume that the source fluxes have well-defined, but a priori unknown values. Using a technique developed by Chen et al. that involves a statistical method called shrinkage estimation, we determine effective area correction factors for each instrument that bring estimated fluxes into the best agreement, consistent with prior knowledge of their effective areas. We expand the technique to allow unique priors on systematic uncertainties in effective areas for each X-ray astronomy instrument and to allow correlations between effective areas in different energy bands. We demonstrate the method with several data sets from various X-ray telescopes.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Junliang Zhou ◽  
Lijuan Wang ◽  
Tujian Xiao ◽  
Zhuang Wang ◽  
Yongya Mao ◽  
...  

In this study, the physiological response of the annual branches of three varieties of pitaya (Xianmi, Fulong, and Zihonglong) in cold stress was investigated using a multivariate statistical method. Physiological change results showed that cold stress could decrease the moisture and chlorophyll contents, on the contrary, increase the relative electric conductivity, the contents of malonadehyde, soluble protein, soluble sugar, and free proline, and enhance the enzyme activities of peroxidase, superoxide dismutase, and catalase. Meanwhile, a comparative proteomic approach was also conducted to clarify the cold resistance-related proteins and pathways in annual pitaya branches. Proteomics results concluded that the cold tolerance of annual pitaya branches could be improved by modulating autophagy. Therefore, we hypothesized that an increased autophagy ability may be an important characteristic of the annual pitaya branches in response to cold stress conditions. Our results provide a good understanding of the physiological responses and molecular mechanisms of the annual pitaya branches in response to cold stress.


Author(s):  
Oksana Danylovych

The article is dedicated to the study of paradigmatic relations of adjectives on the semantic level in the scientific style. Paradigmatic ties in the nucleus and the first periphery are determined and compared. The object of study is adjectives in the scientific style. The subject of the study is paradigmatic ties on the semantic level. The goal is to investigate and compare paradigmatic ties of adjectives in the scientific style. The topicality is caused by the necessity of study of paradigmatic ties of adjectives in the scientific style as they have not been investigated yet. In our study the statistical method was used such as the correlation analysis which helps to determine intensity and character of ties. The more there is the dependence between signs, the more the quantity of coefficient of correlation will approach to 1. In case of the absence of the statistical dependence the quantity of coefficient of correlation will be about zero or equals zero. Using the quantity of usage LSG of adjectives were divided into the nucleus and the first periphery. Due to the correlation analysis paradigmatic ties of LSG of adjectives within the nucleus and within the first periphery and between them were found and analyzed. In our study the statistical method was used such as χІ -which shows presence or absence of a tie. The coefficient K indicates the force (intensity) of ties. Due to it the ties are divided into strong, mean and weak ones. Statistically meaningful ties of lexical-semantic groups (LSG) of adjectives were analyzed. A scientific novelty is in distinguishing the nucleus and the first periphery and investigating paradigmatic ties between them. Conclusions. LSG of adjectives within the first periphery create not a big number of ties in comparison with the number of ties with LSG of adjectives of the nucleus. LSG of adjectives “Natural and physical state” and “Space value of distance and duration” are distinguished as making up the biggest number of ties with nucleus. The study shows that LSG of adjectives within of the first periphery are more independent between themselves and are able to have free ties. Paradigmatic ties of LSG of adjectives within the nucleus have the tendency to dependence and a mutual influence.


2021 ◽  
Author(s):  
◽  
Stacey Dobbie

<p>This thesis presents a comparison of statistical methodologies for cluster verification on ordinal response variables. Methodologies will be applied to a Listening Strategy dataset collected by the Language Learner Strategies research team at the National Institute of Education in Singapore. From this listening dataset, eight clusters suggested by Linguistics theory require verification. The methodologies undertaken is to find which listening strategies have been formed well.  Methods used includes the proportional odds model, confirmatory factor analysis and ordinal agreement model. The proportional odds model is used to establish how well each cluster of questions is built. This is established by checking how similar questions within clusters are. The confirmatory factor analysis is used to verify how well the overall listening clusters have been built. This will be compared to clusters proposed by a statistical method. Lastly, the ordinal agreement model is applied to see how much agreement there is within each of the listening clusters. This will be able to show us which clusters is built better than the other clusters for this listening questionnaire.  Results show that the prediction listening strategy has the highest level of agreement as well as no difference between questions within this cluster. The Socio-affective listening strategy has the lowest level of agreement and very strong evidence of a difference between questions within the cluster. This suggests that the prediction cluster has been formed better than the Socio-affective cluster.</p>


2021 ◽  
Author(s):  
◽  
Stacey Dobbie

<p>This thesis presents a comparison of statistical methodologies for cluster verification on ordinal response variables. Methodologies will be applied to a Listening Strategy dataset collected by the Language Learner Strategies research team at the National Institute of Education in Singapore. From this listening dataset, eight clusters suggested by Linguistics theory require verification. The methodologies undertaken is to find which listening strategies have been formed well.  Methods used includes the proportional odds model, confirmatory factor analysis and ordinal agreement model. The proportional odds model is used to establish how well each cluster of questions is built. This is established by checking how similar questions within clusters are. The confirmatory factor analysis is used to verify how well the overall listening clusters have been built. This will be compared to clusters proposed by a statistical method. Lastly, the ordinal agreement model is applied to see how much agreement there is within each of the listening clusters. This will be able to show us which clusters is built better than the other clusters for this listening questionnaire.  Results show that the prediction listening strategy has the highest level of agreement as well as no difference between questions within this cluster. The Socio-affective listening strategy has the lowest level of agreement and very strong evidence of a difference between questions within the cluster. This suggests that the prediction cluster has been formed better than the Socio-affective cluster.</p>


2021 ◽  
Vol 22 (11) ◽  
pp. 1262-1275
Author(s):  
Sergei V. ARZHENOVSKII ◽  
Tat'yana G. SINYAVSKAYA ◽  
Andrei V. BAKHTEEV

Subject. This article assesses the propensity for material misstatement risk due to unfair actions of persons charged with the financial statements preparation, based on their behavioral traits. Objectives. The article aims to develop a scoring type methodology for identifying the propensity for material misstatement risk due to unfair actions of persons charged with the financial statements preparation. Methods. For the study, we used a multidimensional statistical method of discriminant analysis based on empirical data from an author-conducted survey of 515 employees charged with the financial statements preparation in companies. Results. The article presents a two-stage methodology that helps estimate whether a person has traits associated with a hyperpropensity for financial statements fraud risk. Conclusions and Relevance. The developed methodology for detecting the fraud risk is easy to use. It gives the result in binary form and does not violate the principles of audit ethics. The estimated material misstatement risk due to unfair actions makes it possible to justify the need for appropriate audit procedures when developing a strategy and audit plan.


2021 ◽  
Vol 17 (4) ◽  
pp. 84-93
Author(s):  
E. L. Zadneprovskaya ◽  
T. N. Poddubnaya ◽  
E. A. Panina ◽  
T. A. Dzhum

The market of hotel services is an actively developing market in which innovative technologies of service of guests are widely used; various loyalty and reservation programs are being developed and improved; new approaches to business process management are applied. Benchmarking is a very relevant area designed to assess and select alternative options for the development of the hotel business, defining tasks and improving management efficiency through a deeper study and borrowing approaches successfully implemented by competitors. The aim of the research is to study the current features of benchmarking in the hospitality industry and its impact on the dynamics of enterprise performance. The research methods used are method of competitive analysis, statistical method, generalization method, forecasting. The results and conclusions: the analysis of the state of the hotel services market has shown a steady growth in the number of facilities and consumers of hotel services, which leads to increased intra-industry competition. Benchmarking helps to correlate the operating performance of the hotel business with the performance of the competitive environment, to move away from the subjective assessments of hoteliers and to identify errors in sales policy. In addition, the use of benchmarking allows you to predict the dynamics of demand in order to minimize managerial errors. The conclusions: benchmarking is part of marketing research and the basis for business process planning in the context of choosing strategic activities of the hotel service company. Conducting such a study is focused on providing the hotel with significant competitive advantages, the quintessence of which is the procedure of studying the experience of operating in the market of business leaders.


2021 ◽  
Vol 4 (1) ◽  
pp. 001-011
Author(s):  
Albert K. Arkoh ◽  
Emmanuel Y.H Bobobee ◽  
Ahmad Addo

Uniformity in plant spacing, evenness of dropping, planter capacity and among others has been identified as constraints facing planter performance. The main objective of the study was to evaluate the technical performance of the developed double row yam minisett (DRYM) planter. Category (I) tractor 50 hp was used to carry out field trials to determine the metering efficiency, effective field capacity, evenness of dropping, fuel consumption and wheel slippage. Three (3) yam varieties (pona, dente and CRI afase biri) of the average weight of 50 g with moisture content (82 %) were used for the test. Multivariate and (ANOVA) statistical method was used for analyzing the similarities among the tractor speed using OriginPro 2018 software. Metering efficiency (80.4%), effective field capacity (3.84 h/ha), field efficiency (66.6%), evenness of dropping (81.00%), and wheel slip (3.39%) were recorded. The use of developed planter will be expected to reduce human drudgery and also timeliness improvement. The study concluded that planter should be used on relatively flat (ploughed-harrowed) land to avoid wheel not touching the ground.


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