scholarly journals A statistical study of pre-monsoon weather over south Bengal using descriptive and inferential techniques

MAUSAM ◽  
2021 ◽  
Vol 61 (4) ◽  
pp. 547-552
Author(s):  
S. DAS GUPTA ◽  
U. K. DE

Statistical data summarization techniques, curve fitting methods and statistical tests, both parametric and non-parametric, have been applied to form a comprehensive idea about pre-monsoon weather over South Bengal situated in the northeastern part of the Indian sub-continent. The work is based on surface data recorded at 15 major observatories during the period 1969-2000, spread across the western plateau and highlands, Rarh and Gangetic region of South Bengal. The homogeneity of pre-monsoon rainfall and its variability over different stations has been studied using Bartlett`s and Kruskal Wallis tests. For stations with complete weather information for at least 30 consecutive years, time series analysis has been carried out on rainfall data for a climatological overview of long-term behaviour, seasonal and cyclical fluctuations of pre-monsoon rainfall in those areas. This paper, apart from being a regional study, highlights the use of certain parametric and non-parametric tests, not so widely used in the context of climatology.

MAUSAM ◽  
2021 ◽  
Vol 43 (1) ◽  
pp. 77-86
Author(s):  
S. K. SUBRAMANIAN ◽  
S. V. PALANDE ◽  
B.N. DEWAN ◽  
S. K. DIKSHIT ◽  
LAWRENCE JOSEPH

The monthly and annual rainfall data for 35 meteorological sub-divisions for the 87-year period (1901-1987) have been used to study the trends and periodicities of monsoon and annual rainfall series. A number of distribution-free statistical tests have been applied to the rainfall series for testing non-randomness. Comparison of the decadewise means with the mean of the whole period showed that, for the country as a whole, the annual rainfall indicated four different climatic periods -two periods of above normal rainfall from 1960-1965 and from 1975 onwards and two periods of below normal rainfall from 1901-1915 and 1965-1975 whereas the monsoon rainfall showed two different climatic periods-a period of below normal rainfall from 1901-1920 and a period of above normal rainfall from 1920 onwards. The series were also subjected to low-passfilters which showed the presence of significant long term trend for a few sub-divisions. The power spectrum analysis for the annual and monthly rainfall series for a large number of sub-divisions showed significant periodicities of 2. 1-3.6 years, which correspond to the frequency range of the QBO. In addition, periodicities of 5.1 to 10.0 years and 19.3 years or more were also significant for a number of sub-divisions.  


Forecasting ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 1-16
Author(s):  
Hassan Hamie ◽  
Anis Hoayek ◽  
Hans Auer

The question of whether the liberalization of the gas industry has led to less concentrated markets has attracted much interest among the scientific community. Classical mathematical regression tools, statistical tests, and optimization equilibrium problems, more precisely non-linear complementarity problems, were used to model European gas markets and their effect on prices. In this research, the parametric and nonparametric game theory methods are employed to study the effect of the market concentration on gas prices. The parametric method takes into account the classical Cournot equilibrium test, with assumptions on cost and demand functions. However, the non-parametric method does not make any prior assumptions, a factor that allows greater freedom in modeling. The results of the parametric method demonstrate that the gas suppliers’ behavior in Austria and The Netherlands gas markets follows the Nash–Cournot equilibrium, where companies act rationally to maximize their payoffs. The non-parametric approach validates the fact that suppliers in both markets follow the same behavior even though one market is more liquid than the other. Interestingly, our findings also suggest that some of the gas suppliers maximize their ‘utility function’ not by only relying on profit, but also on some type of non-profit objective, and possibly collusive behavior.


2014 ◽  
Vol 112 (11) ◽  
pp. 2729-2744 ◽  
Author(s):  
Carlo J. De Luca ◽  
Joshua C. Kline

Over the past four decades, various methods have been implemented to measure synchronization of motor-unit firings. In this work, we provide evidence that prior reports of the existence of universal common inputs to all motoneurons and the presence of long-term synchronization are misleading, because they did not use sufficiently rigorous statistical tests to detect synchronization. We developed a statistically based method (SigMax) for computing synchronization and tested it with data from 17,736 motor-unit pairs containing 1,035,225 firing instances from the first dorsal interosseous and vastus lateralis muscles—a data set one order of magnitude greater than that reported in previous studies. Only firing data, obtained from surface electromyographic signal decomposition with >95% accuracy, were used in the study. The data were not subjectively selected in any manner. Because of the size of our data set and the statistical rigor inherent to SigMax, we have confidence that the synchronization values that we calculated provide an improved estimate of physiologically driven synchronization. Compared with three other commonly used techniques, ours revealed three types of discrepancies that result from failing to use sufficient statistical tests necessary to detect synchronization. 1) On average, the z-score method falsely detected synchronization at 16 separate latencies in each motor-unit pair. 2) The cumulative sum method missed one out of every four synchronization identifications found by SigMax. 3) The common input assumption method identified synchronization from 100% of motor-unit pairs studied. SigMax revealed that only 50% of motor-unit pairs actually manifested synchronization.


Author(s):  
Manoochehr Ghorbanpour ◽  
Mohammad Ali Seyfrabie ◽  
Babak Yousefi

Objective. Patients undergoing Soave surgery for Hirschsprung's disease are at risk for some complications. The aim of this study was to investigate such short-term and long-term complications and evaluate the outcome of the operation in these patients. Methods. A case series study was carried out during the last 12 years, during 2007 to 2018 in Besat hospital of Hamadan. Data collection conducted using a checklist includes questions about demographic information, clinical features, and short-term and long-term complications, and consequences of post-operative surgery. The findings of the study were analyzed using SPSS software version 20 and appropriate statistical tests. P-value less than 0.05 was considered statistically significant. Results. A total of 55 children underwent Soave surgery during the last 12 years in Besat Hospital Hamadan, Iran. The mean age of the patients was 38±10 days during surgery, of which 56.4% were female. The mean hospital stay was 7.3 days. Also, the mean weight of children at birth was 2970±447 gr. Most of the patients were born as NVD (52.7%) and term (74.5%). The most common comorbidity was congenital heart disease. The most common short-term complication was intestinal obstruction in 14 patients (25.5%) and the most frequent long-term complication was intestinal obstruction and constipation (27.3% each cases). The mortality rate of patients in this study was 14.5% in total. Conclusions. One stage surgical procedure in Hirschsprung's disease is a safe and effective method, but care should be taken in choosing patients and patients should be monitored for possible complications, so that they can be considered and implemented for proper treatment.


10.5772/56860 ◽  
2013 ◽  
Vol 5 ◽  
pp. 43 ◽  
Author(s):  
Henry J. Quesada-Pineda ◽  
Johanna Madrigal

This paper presents the results of a longitudinal study of four continuous improvement (CI) leader companies in two different global regions. The goal of the research was to understand how employee perception of different factors that impact the long-term sustainability of the CI process might change over time. Quantitative data analysis was used to capture and statistically analyse employee perceptions by CI factor, time, and geographical location. After validation and reduction techniques were applied to the research model, five factors were singled out: change management, strategic planning, knowledge management, performance management, and sustainability of the CI process. For two of the four companies, no changes in perception were found during the period of study for any of the factors. For the other two, however, changes were perceived in at least one of the five constructs in the study. Changes were also found across the regions included. By leveraging the quantitative analysis with qualitative data collected through interviews and visits to the case study companies, we were able to explain the changes in perception and single out the best CI management process to sustain CI in the long term.


1990 ◽  
Vol 117 (2) ◽  
pp. 407-413 ◽  
Author(s):  
A. Kitts

AbstractThe paper comments on the estimation and sensitivity of the retail price inflation component of the stochastic financial model proposed by Professor Wilkie. Statistical tests provide evidence of nonindependence and non-normality of residuals, suggesting non-linearity. However, it is noted that the model is most sensitive to the assumption of long-term mean inflation.


BMJ ◽  
2012 ◽  
Vol 344 (apr11 2) ◽  
pp. e2537-e2537
Author(s):  
P. Sedgwick

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