Discovering promising research themes in a scientific domain by evaluating semantic information extracted from bibliometric databases represents challenging task for Natural Language Processing (NLP). While existing NLP methods generally characterize the topics using unique key terms, we take step further more accurately modeling as finite sets of terms. The proposed approach involves two stage...

temperature is one of the most important climate variables that many economic and social plans related to its changes. because of the importance of this issue, this study investigated the changes of it in the province khuzestan. meteorological data that used in this study is mean temperature in annual and seasonal timescale. the study area is abadan, ahwaz, dezful and omidiye stations. for anal...

abstract in this research, temporal trends of reference evapotranspiration (et0) values were investigated in arid regions of iran. for this purpose, the meteorological observations collected from 11 high quality meteorological sites for a 41-year period (1965-2005) were used and statistically significant et0 trends in the monthly, seasonal and annual time basis were detected by the non-parametr...

drought is one of the natural phenomena which occurs in all climates in different parts of the world. iran is located in the dry belt of the world. the increase of desertification, drought reoccurrence, and destruction by human in this geographical region needs more studies on spatial and temporal trend of rainfall. in this study, trends of climatic drought during 1975-76/ 2004-05 in seasonal a...

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...

introduction: studying long-term trend changes of meteorological parameters is one of the routine methods in atmospheric studies, especially in the climate change subject. among the meteorological parameters, temperature is always considered as one of the most atmospheric elements and studying it in order to gain a better understanding of the climate change phenomenon, has been effective. in ad...

this analysis was conducted on 31 synoptic stations in iran. initially, the mann-kendall test was administered in order to analyse the trend of alterations of these two components over time and the results suggest that 16% of the stations show significant relationship with annual precipitation (positive and negative). more stations showed significant relationships between sunspots and minimum a...

The Mann-Kendall test is a commonly-used nonparametric test for time trend. However, the standard P-values obtained from it are based on an assumption of independence between observations (since the theory is that of the Kendall correlation). However, observations in time series are often autocorrelated: knowing that one observation is larger than the mean may tell you that the next observation...