نتایج جستجو برای: kendall trend tests

تعداد نتایج: 454958  

2004

Kendall Rank Correlation Let (X1, Y1), · · · , (Xn, Yn) be a bivariate random sample of size n. The Pearson correlation coefficient provides an optimal measure of the degree of association between the X’s and the Y ’s when the sample is drawn from a bivariate normal distribution. The Pearson correlation coefficient is reasonably robust for many other distributions as well. The Kendall correlati...

Journal: :international journal of advanced biological and biomedical research 2013
keivan khalili farshad ahmadi yagub dinpashoh ahmad fakheri fard

one of the most important hydrological time series task is to determine if there is any trend in the data and how to achieve stationarity when there is nonstationarity behavior in data. detecting trend and stationarity in hydrological time series may help us to understand the possible links between hydrological processes and global climate changes. in this study yearly, monthly and daily stream...

Journal: :journal of biostatistics and epidemiology 0
elham ahmadnezhad national institute of health research, tehran university of medical sciences, tehran, iran zhaleh abdi department of health expenditure, national institute of health research, tehran university of medical sciences, tehran, iran abolhassan safdari department of infectious disease, zahedan university of medical sciences, zahedan, iran farshid fayyaz-jahani academic center for education, culture and research center, urmia, iran sheida malek-afzali department of environment and occupational health center, ministry of health, tehran, iran soraya fathollahi department of health in disasters and emergencies, international campus, tehran university of medical sciences, tehran, iran

background & aim: the aim of the study was to define the epidemiological characteristics of most important infectious diseases in iran in recent decades. methods & materials: this was a situation trend analysis of infectious diseases (vector and water borne disease, and food borne diseases) in recent decades based on data availability. three significance levels were used for mann-kendall test (...

1999
Jie Tian

This paper presents user-friendly SAS macro and SAS programs to check the three parts of a time series: Trend, Cyclical patterns, and Stationarity. The SAS macro KENDALL performs the trend analysis. Seasonal Kendall Trend analysis, including summery statistics; overall Tau and the P-value of the test for trend; monthly Tau values, the corresponding P-values for each month; the Seasonal Kendall ...

جعفرزاده, مریم سادات, حشمت‌پور, علی, روحانی, حامد, کاشانی, مجتبی,

  Due to global warming, and its resulting changes in the frequency and amount of precipitation and temperature, there has been a great concern on climate change impacts by the scientific community. This study focuses on trend analysis of annual and seasonal rainfall (P), maximum temperature (Tmax) and minimum temperature (Tmin) time series from seven meteorological stations in Gorgranrood rive...

Journal: :تحقیقات آب و خاک ایران 0
فرشاد فتحیان دانشگاه تربیت مدرس سعید مرید دانشگاه تربیت مدرس

global warming has brought about changes in meteorological variable time series. these changes, accompanied with serious human intervention in nature, has resulted in hydrological changes. so the effects can be tracked down by the trend of the time series. the purpose of this study is to analyze and compare the monthly and annual trends of temperature, precipitation as well as stream flow time ...

Journal: :پژوهش های جغرافیای طبیعی 0
سهراب حجام دانشیار دانشگاه آزاد اسلامی، واحد علوم و تحقیقات یونس خوشخو کارشناس ارشد هواشناسی کشاورزی، دانشگاه تهران رضا شمس الدین وندی کارشناس ارشد هواشناسی کشاورزی، دانشگاه تهران

abstract the aim of this paper is to investigate annual and seasonal precipitation trends of some selective meteorological stations of central region in iran using non-parametric methods. two non-parametric methods including mann-kendall and sen's estimator slope methods were used here to analyze the seasonal and annual trends of precipitation data. some 48 meteorological stations in centr...

2007
O. Thas L. Van Vooren

In this paper two nonparametric tests for monotonic trend detection are compared with respect to their power and accuracy. The importance of comparing powers at equal empirical signiicance levels rather than nominal levels, is stressed. Therefore, an appropriate graphical method is presented. The eeect of the sampling frequency is also assessed using a trajectory representation that visualizes ...

Given the importance of climate change issue, consideration of the climate and hydrological data trend has become very important. This study aimed to evaluate the effectiveness of different methods to remove the effect of autocorrelation in assessing the trend of parameters such as temperature, precipitation and discharge of the Eastern Gorganrood Basin, Golestan Province. For this purpose, in ...

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