scholarly journals Time Series Analysis of Cutaneous Leishmaniasis in Sabzevar Northeastern Iran Using Segmented Regression Model

2020 ◽  
Vol 7 (3) ◽  
pp. 101-106
Author(s):  
Hadis Barati ◽  
Erfan Ayubi ◽  
Sohrab Iranpour ◽  
Mohammad Barati ◽  
Ahmad Allah-Abadi ◽  
...  
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
Regression Model ◽  
Cutaneous Leishmaniasis ◽  
Change Point ◽  
Period Effect ◽  
Segmented Regression ◽  
Rural Districts ◽  
Series Analysis ◽  
Segmented Regression Model

Background and aims: Cutaneous leishmaniasis (CL) is one of the most important parasitic diseases in the world. Sabzevar city is endemic area for CL in the north east of Iran. The aim of this study was to evaluate the time distribution of cutaneous leishmaniasis (CL) in Sabzevar County using the segmented regression model. Methods: This ecological study used the existing data related to the rural districts of Sabzevar County that were obtained from the Health Deputy of this county during 2011-2017. In addition, the segmented regression model was applied to evaluate the time trend of CLs. Finally, Joinpoint software was used for time series analysis. Results: A total of 1912 CL cases occurred in Sabzevar County from 2011 to 2017, with an incidence rate of 93.61 per 100000. The highest and lowest observed incidence rates were in 2011 (25 per 10000 persons) and 2015 (3.24 per 10000 persons), respectively. Based on the results, the annual incidence of CL in the intended region decreased and the annual percent change was equal to -22.40. Further, the time series analysis using segmented regression by rural districts showed a change point in the trend of the incidence of leishmaniasis in three rural districts (Pain Joveyn and Joghatai in 2014 and Qasabeh-ye Sharqi in 2013). In other words, the trend was different before and after the change point in the mentioned districts. Conclusion: In general, the results indicated that interventional, preventive, and therapeutic measures for breaking the chain of CL transmission in Sabzevar have been desirable in recent years. Eventually, it is suggested that further time-series studies be conducted at the level of the month or a longer interval in order to better evaluate the period effect and secular trend.

scholarly journals Analysis and Forecast of Global Civil Aviation Accidents for the Period 1942-2016

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Yafei Li
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
Change Point ◽  
Research Result ◽  
Sudden Change ◽  
Civil Aviation ◽  
Aviation Accidents ◽  
Series Analysis ◽  
The World

With the increase of global civil aviation transportation, more and more researchers pay attention to the analysis of civil aviation accidents. Time series analysis can obtain the variation law in a large amount of data, and there is no research result of aviation accident time series yet. Based on the Mann-Kendall trend analysis and mutation analysis methods, this paper studied the change trend of accidents and casualties in different flight stages of civil aviation and built ARIMA (Autoregressive Integrated Moving Average model) time series analysis model to predict the number of civil aviation accidents and casualties by the long-term data in the world. (1) The number of civil aviation accidents fluctuates generally in the world; from 1942 to 2016, there were two fluctuation periods of civil aviation accidents. (2) The number of global civil aviation casualties from 1942 to 2016 showed a parabola trend of increasing first and then decreasing. The highest number of casualties appeared in 1972, which was 2373; on the different flight stages, the number of accidents was different. In the air route and approach phase, the number of accidents was the most, and the number of casualties was more than other flight phases, accounting for about 50% of the whole flight phase. (3) In addition to the land phase, the number of accidents showed a significant decrease in other flight phases; while the air route and total number of casualties decreased significantly, the number of casualties at other flight phases did not decrease significantly. There were no sudden changes in the number of global civil aviation accidents and approach casualties. (4) The sudden change point of the global civil aviation casualties was 2013, the sudden change point of the air route stage accidents was 1980, the sudden change point of approach stage accidents was 2012, and the sudden change point of air route stage casualties was 2006. According to the ARIMA (1,0,1) model, the numbers of global civil aviation accidents and casualties were predicted to 2025. Through time series research, we have explored the variation law in the historical data of long-term aviation accidents and predicted the possible changes of future aviation accidents, providing data reference for aviation safety research.

A time series analysis of environmental and metrological factors impact on cutaneous leishmaniasis incidence in an endemic area of Dehloran, Iran

2017 ◽  
Vol 24 (16) ◽  
pp. 14117-14123 ◽  
Author(s):  
Ali Nikonahad ◽  
Ali Khorshidi ◽  
Hamid Reza Ghaffari ◽  
Hamideh Ebrahimi Aval ◽  
Mohammad Miri ◽  
...  
Keyword(s):  
Time Series ◽  
Time Series Analysis ◽  
Cutaneous Leishmaniasis ◽  
Endemic Area ◽  
Series Analysis
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