Fault prognosis is one of the key techniques for prognosis and health management,and an effective fault feature can improve prediction accuracy and performance. A novel approach of feature extraction for fault prognos...Fault prognosis is one of the key techniques for prognosis and health management,and an effective fault feature can improve prediction accuracy and performance. A novel approach of feature extraction for fault prognosis based on fault trend analysis was proposed in this paper. In order to describe the ability of tracking fault growth process,definitions and calculations of fault trackability was developed, and the feature which had the maximum fault trackability was selected for fault prognosis. The vibration data in bearing life tests were used to verify the effectiveness of the method was proposed. The results showed that the trackability of energy entropy for bearing fault growth was the maximum,and it was the best fault feature among selected features root mean square( RMS),kurtosis,new moment and energy entropy. The proposed approach can provide a better strategy for fault feature extraction of bearings in order to improve prediction accuracy.展开更多
Effective disturbance indices for Hyrcanian forests in Kheyroud,Nowshahr,Iran were determined.The study area was divided into landscape mosaics based on ecosystem parameters including profile type,slope and elevation....Effective disturbance indices for Hyrcanian forests in Kheyroud,Nowshahr,Iran were determined.The study area was divided into landscape mosaics based on ecosystem parameters including profile type,slope and elevation.Co-occurrence texture indices were derived as forest disturbance factors on the first five bands of Landsat TM,ETM+and OLI images for the prevailing wood harvest disturbance regimes.These indices were screened using ten types of trend analyses and used for modeling disturbance of the harvesting regime through artificial neural networks.The results show that the selected indices can be useful in distinguishing areas with different disturbance intensities and as such,used in the context of health assessment through the health distance method.The accuracy of the health maps derived from the indices[increasing disturbance]led to give rise higher disturbance classification accuracy.展开更多
Background: Currently, surgical resection represents the only curative treatment for pancreatic cancer(PC), however, the majority of tumors are no longer resectable by the time of diagnosis. The aim of this study was ...Background: Currently, surgical resection represents the only curative treatment for pancreatic cancer(PC), however, the majority of tumors are no longer resectable by the time of diagnosis. The aim of this study was to describe time trends and distribution of pancreaticoduodenectomies(PDs) performed for treating PC in Brazil in recent years. Methods: Data were retrospectively obtained from Brazilian Health Public System(namely DATASUS) regarding hospitalizations for PC and PD in Brazil from January 2008 to December 2015. PC and PD rates and their mortalities were estimated from DATASUS hospitalizations and analyzed for age, gender and demographic characteristics. Results: A total of 2364 PDs were retrieved. Albeit PC incidence more than doubled, the number of PDs increased only 37%. Most PDs were performed in men(52.2%) and patients between 50 and 69 years old(59.5%). Patients not surgically treated and those 70 years or older had the highest in-hospital mortality rates. The most developed regions(Southeast and South) as well as large metropolitan integrated municipalities registered 76.2% and 54.8% of the procedures, respectively. LMIM PD mortality fluctuated, ranging from 13.6% in 2008 to 11.8% in 2015. Conclusions: This study suggests a trend towards regionalization and volume-outcome relationships for PD due to PC, as large metropolitan integrated municipalities registered most of the PDs and more stable mortality rates. The substantial differences between PD and PC increasing rates reveals a limiting step on the health system resoluteness. Reduction in the number of hospital beds and late access to hospitalization, despite improvement in diagnostic methods, could at least in part explain these findings.展开更多
Long-term,ground-based daily global solar radiation (DGSR) at Zhongshan Station in Antarctica can quantitatively reveal the basic characteristics of Earth’s surface radiation balance and validate satellite data for t...Long-term,ground-based daily global solar radiation (DGSR) at Zhongshan Station in Antarctica can quantitatively reveal the basic characteristics of Earth’s surface radiation balance and validate satellite data for the Antarctic region.The fixed station was established in 1989,and conventional radiation observations started much later in 2008.In this study,a random forest (RF) model for estimating DGSR is developed using ground meteorological observation data,and a highprecision,long-term DGSR dataset is constructed.Then,the trend of DGSR from 1990 to 2019 at Zhongshan Station,Antarctica is analyzed.The RF model,which performs better than other models,shows a desirable performance of DGSR hindcast estimation with an R^2 of 0.984,root-mean-square error of 1.377 MJ m^(-2),and mean absolute error of 0.828 MJ m^(-2).The trend of DGSR annual anomalies increases during 1990–2004 and then begins to decrease after 2004.Note that the maximum value of annual anomalies occurs during approximately 2004/05 and is mainly related to the days with precipitation (especially those related to good weather during the polar day period) at this station.In addition to clouds and water vapor,bad weather conditions (such as snowfall,which can result in low visibility and then decreased sunshine duration and solar radiation) are the other major factors affecting solar radiation at this station.The high-precision,longterm estimated DGSR dataset enables further study and understanding of the role of Antarctica in global climate change and the interactions between snow,ice,and atmosphere.展开更多
Social media data created a paradigm shift in assessing situational awareness during a natural disaster or emergencies such as wildfire, hurricane, tropical storm etc. Twitter as an emerging data source is an effectiv...Social media data created a paradigm shift in assessing situational awareness during a natural disaster or emergencies such as wildfire, hurricane, tropical storm etc. Twitter as an emerging data source is an effective and innovative digital platform to observe trend from social media users’ perspective who are direct or indirect witnesses of the calamitous event. This paper aims to collect and analyze twitter data related to the recent wildfire in California to perform a trend analysis by classifying firsthand and credible information from Twitter users. This work investigates tweets on the recent wildfire in California and classifies them based on witnesses into two types: 1) direct witnesses and 2) indirect witnesses. The collected and analyzed information can be useful for law enforcement agencies and humanitarian organizations for communication and verification of the situational awareness during wildfire hazards. Trend analysis is an aggregated approach that includes sentimental analysis and topic modeling performed through domain-expert manual annotation and machine learning. Trend analysis ultimately builds a fine-grained analysis to assess evacuation routes and provide valuable information to the firsthand emergency responders<span style="font-family:Verdana;">.</span>展开更多
The purpose of this paper is to investigate the trend of precipitation in Kilkis region (Greece) at </span></span><span style="font-family:Verdana;"><span style="font-family:Verdana...The purpose of this paper is to investigate the trend of precipitation in Kilkis region (Greece) at </span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">the </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">site and regional level in various time scales. At </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">the </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">site level, the precipitation trend was analyzed using three tests: 1) Mann</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Kendall, 2) Sen’s T and 3) Spearman while the trend slope was estimated using the Sen’s estimator. At </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">a </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">regional level, nonparametric spatial tests such as Regional Average Mann</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Kendall (RAMK) and BECD’s (Bootstrap Empirical Cumulative Distributions) were elaborated with and without the effect of cross correlation. The trend of precipitation was noticed generally downward at annual time scale and statistically significant at 5% level of significance only in only one station. The results of the analysis of trends at </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">the </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">regional level showed in total the influence of cross correlation in the time series since the number of trends detected is reduced when cross correlation is preserved. Precipitation data from 12 stations were used. The study results benefit water resource management, drought mitigation, socio-economic development, and sustainable agricultural planning </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">in </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">the region.展开更多
This study aims at analyzing the tendency and change in the research on construction grammar from 2010 to 2020.Descriptively,this study includes the publication year,research topic,research direction,research content,...This study aims at analyzing the tendency and change in the research on construction grammar from 2010 to 2020.Descriptively,this study includes the publication year,research topic,research direction,research content,and the research methods.Twenty-four CSSCI journals were selected as the research samples using the keyword–“Construction Grammar.”The research topics mainly include Chinese construction research,foreign language construction research,and comparative studies on Chinese and other language constructions.The results showed that there are many Chinese construction research,but the other two research topics still require improvement.Ontology research was the main focus;acquisition research and teaching research are worthy for further exploration.Case studies and theoretical studies were the most concerned contents,whereas studies on language acquisition,pedagogy,and corpus construction were feeble.Qualitative description and theoretical review were the most popular methods,while empirical,quantitative,and diachronic analyses were less frequently used.After analyzing the trends,it has been predicted that the research on construction grammar would continue to heat up in the future,and there would be more research directions and contents along with diversified research methods.展开更多
Background:Afghanistan is suffering from 40-year chronic conflicts,displacement,and demolition of its infrastructure.Afghanistan mortality survey 2010 shows nearly 46%of all deaths in the country were attributed to no...Background:Afghanistan is suffering from 40-year chronic conflicts,displacement,and demolition of its infrastructure.Afghanistan mortality survey 2010 shows nearly 46%of all deaths in the country were attributed to noncommunicable diseases(NCDs).In this study,we aimed to understand the differences in mortality and premature death due to NCDs by sex and the trend for the next 8 years.Methods:We applied trend analysis using the secondary data from the Institute for Health Metrics and Evaluation,Global Burden of Diseases 2019.The information on NCD mortality,NCD deaths attributed to its risk factors,NCD percent of total years lived with disability(YLDs)attribution to each risk factor extracted from this database from 2008 to 2019.We investigated the trend from 2008 to 2019 for the mentioned factors and then forecast their trends until 2030.Results:Our study shows that Afghanistan has had an increasing death number due to NCDs from 2008 to 2019(50%for both sexes)and this will reach nearly 54%by 2030.Currently,half of NCDs deaths are premature in Afghanistan.The mortality rate and prevalence of risk factors are higher among women.More than 70%of YLDs will be due to NCDs in Afghanistan till 2030.Five risk factors including high systolic blood pressure(28.3%),high body mass index(23.4%),high blood glucose(20.6%),high low-density lipoprotein cholesterol(16.3%),and smoking(12.3%)will have the highest contribution to NCDs death in 2030,respectively.Conclusions:In general,our study indicates that without any specific intervention to address NCDs in Afghanistan,not only the Sustainable Development Goal target for NCDs will not be met,but an increase in almost all risk factors prevalence,as well as NCD mortality,will be seen in Afghanistan.展开更多
The aim of this study is to establish the prevailing conditions of changing climatic trends and change point dates in four selected meteorological stations of Uyo, Benin, Port Harcourt, and Warri in the Niger Delta re...The aim of this study is to establish the prevailing conditions of changing climatic trends and change point dates in four selected meteorological stations of Uyo, Benin, Port Harcourt, and Warri in the Niger Delta region of Nigeria. Using daily or 24-hourly annual maximum series (AMS) data with the Indian Meteorological Department (IMD) and the modified Chowdury Indian Meteorological Department (MCIMD) models were adopted to downscale the time series data. Mann-Kendall (MK) trend and Sen’s Slope Estimator (SSE) test showed a statistically significant trend for Uyo and Benin, while Port Harcourt and Warri showed mild trends. The Sen’s Slope magnitude and variation rate were 21.6, 10.8, 6.00 and 4.4 mm/decade, respectively. The trend change-point analysis showed the initial rainfall change-point dates as 2002, 2005, 1988, and 2000 for Uyo, Benin, Port Harcourt, and Warri, respectively. These prove positive changing climatic conditions for rainfall in the study area. Erosion and flood control facilities analysis and design in the Niger Delta will require the application of Non-stationary IDF modelling.展开更多
The National Central Cancer Registry of China(NCCRC)updated their nationwide statistics of cancer incidence and mortality in China according to 2013 population-based cancer registration data(due to the time required f...The National Central Cancer Registry of China(NCCRC)updated their nationwide statistics of cancer incidence and mortality in China according to 2013 population-based cancer registration data(due to the time required for data collection,quality control and analysis,the latest cancer statistics available in China have a 3-year lag behind the current year).In this report,the NCCRC provides a comprehensive review of cancer incidence and mortality rates,as well as the statistics overall and by geographical area,cancer sites or age groups(Chen et al.,2017a).It shows that the burden of cancer展开更多
Groundwater accounts for about half of the water use for irrigation in India.The fluctuation pattern of the groundwater level is examined by observing rainfall replenishment and monitoring wells.The southern part of R...Groundwater accounts for about half of the water use for irrigation in India.The fluctuation pattern of the groundwater level is examined by observing rainfall replenishment and monitoring wells.The southern part of Rajasthan has experienced abrupt changes in rainfall and has been highly dependent on groundwater over decades.This study presents the impact of over-dependence on groundwater usage for irrigation and other purposes,spatially and temporally.Hence,the objective of this study is to examine the groundwater level trend by using statistical analysis and geospatial technique.Rainfall factor was also studied in groundwater level fluctuation during 2009-2019.To analyze the influence of each well during recharge or withdrawal of groundwater,thiessien polygonswere generated from them.In the Jakham River basin,75 wells have been identified for water level trend study using the Mann-Kendall statistical test.The statistics of trend analysis show that 15%wells are experiencing water level decline in pre-monsoon,while very low percentage of wells have such trend during post-monsoon season.The average rate of water level decline is 0.245 m/a in pre-monsoon and 0.05 m/a in post-monsoon.The aquifer recharge potential is also decreasing by year.it is expected that such type of studies will help the policy makers to adopt advanced management practices to ensure sustainable groundwater resource management.展开更多
Based on the monitoring data of precipitation and runoff series from 1953 to 2013 and groundwater exploitation from 1977 to 2013 in Jinghui Irrigation Area,especially the evolution of water resources during the growth...Based on the monitoring data of precipitation and runoff series from 1953 to 2013 and groundwater exploitation from 1977 to 2013 in Jinghui Irrigation Area,especially the evolution of water resources during the growth period of main crops,the trend test of precipitation and runoff series was carried out by using Spearman rank correlation test and R/S analysis.The results showed that the annual mean precipitation and runoff and the growth period of main crops showed a downward trend,and the changes in the future were similar to those in the past;the amount of groundwater exploitation has not changed much,which is about 150 million m^3.The research results can provide scientific basis for efficient utilization and reasonable allocation of water resources in irrigation area,and provide technical support for the development of modern agriculture.展开更多
[Objective] The changes trend of temperature and frost-free period in Xingtai in recent 53 years were studied.[Method] According to the climate data of Xingtai City and Nangong County in 1958-2010,the changes trend of...[Objective] The changes trend of temperature and frost-free period in Xingtai in recent 53 years were studied.[Method] According to the climate data of Xingtai City and Nangong County in 1958-2010,the changes trend of the temperature,the first and the last frost day,and the frost-free days in Xingtai were studied.The characteristics of the changes of temperature and frost-free days in Xingtai in recent 53 years were studied.[Result] No matter in city or countryside,the annual average temperature was increasing.The climate tendency rates in Xingtai and Nangong were about 0.5 and 0.2 ℃/10 a respectively.Especially,since 1996,the annual average temperature increasing trend was about 1.0 ℃/10 a.The average temperature of the four seasons was also climbing and was similar to the increasing span of the annual average temperature.The annual average temperature increasing span was the largest in winter.And the increase of the annual average temperature in winter was the largest and the increase of the annual average temperature was caused by the increase of the average temperature in winter.The urban annual average temperature was obviously higher than that of the countryside,which reflected the characteristics of tropical island effect.No matter in the city or the countryside,the early frost day,final frost day and frost-free day showed same tendency,namely,the delay of early frost day,advance of final-frost day,extension of frost-free day;the day of urban early frost was late than that of the countryside,and the final frost day was earlier than that of the countryside,the frost-free days were longer than that of countryside and indirectly influenced by urban heat effect.[Conclusion] The study provided theoretical basis for the development and application of thermal resources in Xingtai.展开更多
[Objective] The research aimed to analyze the variation trend of rainfall in Xingtai area of Hebei Province in recent 48 years. [Method] According to the annual and seasonal rainfall data in Xingtai, Nangong, Shahe an...[Objective] The research aimed to analyze the variation trend of rainfall in Xingtai area of Hebei Province in recent 48 years. [Method] According to the annual and seasonal rainfall data in Xingtai, Nangong, Shahe and Neiqiu during 1963-2010, by using the interannual variation rainfall line chart, trend chart and climatic variability, the variation trend of rainfall in Xingtai area in recent 48 years was analyzed. [Result] The annual rainfall in Xingtai area during 1963-2010 presented yearly decrease trend, and the decrease velocity was 18.0 mm/10 a. The annual rainfall in Xingtai, Nangong, Shahe and Neiqiu roughly presented same trend (linear decrease). Except spring rainfall in Xingtai area in recent 48 years slightly increased, the rainfall in summer, autumn and winter all presented linear decrease trend. The decrease velocity of summer rainfall was the maximum. The decrease of summer rainfall played decisive role in rainfall decrease of the whole year. The decrease trend of winter rainfall wasn't as significant as that of autumn rainfall. [Conclusion] The research provided theoretical basis for studying climatic variation characteristics in Xingtai area under the climatic warming background.展开更多
Trend and stationarity analysis of climatic variables are essential for understanding climate variability and provide useful information about the vulnerability and future changes,especially in arid and semi-arid regi...Trend and stationarity analysis of climatic variables are essential for understanding climate variability and provide useful information about the vulnerability and future changes,especially in arid and semi-arid regions.In this study,various climatic zones of Iran were investigated to assess the relationship between the trend and the stationarity of the climatic variables.The Mann-Kendall test was considered to identify the trend,while the trend free pre-whitening approach was applied for eliminating serial correlation from the time-series.Meanwhile,time series stationarity was tested by Dickey-Fuller and Kwiatkowski-Phillips-Schmidt-Shin tests.The results indicated an increasing trend for mean air temperature series at most of the stations over various climatic zones,however,after eliminating the serial correlation factor,this increasing trend changes to an insignificant decreasing trend at a 95%confidence level.The seasonal mean air temperature trend suggested a significant increase in the majority of the stations.The mean air temperature increased more in northwest towards central parts of Iran that mostly located in arid and semiarid climatic zones.Precipitation trend reveals an insignificant downward trend in most of the series over various climatic zones;furthermore,most of the stations follow a decreasing trend for seasonal precipitation.Furthermore,spatial patterns of trend and seasonality of precipitation and mean air temperature showed that the northwest parts of Iran and margin areas of the Caspian Sea are more vulnerable to the changing climate with respect to the precipitation shortfalls and warming.Stationarity analysis indicated that the stationarity of climatic series influences on their trend;so that,the series which have significant trends are not static.The findings of this investigation can help planners and policy-makers in various fields related to climatic issues,implementing better management and planning strategies to adapt to climate change and variability over Iran.展开更多
Pavement roughness(IRI—International Roughness Index values)influence the stability of traffic movements both on intercity roads and urban roads.This study is to determine the exact locations of critical pavement rou...Pavement roughness(IRI—International Roughness Index values)influence the stability of traffic movements both on intercity roads and urban roads.This study is to determine the exact locations of critical pavement roughness values that affect traffic motion stability and comfort in city centre highway arteries.Roughness data with 10 m intervals were collected on a 3140 m divided road containing three consecutive signalized intersections in the city centre arterial.These data were analysed using the distance-dependent Mann-Kendall trend analysis method and checkerboard model.The sections where roughness is important were determined at a 95%confidence interval.The results will show where future pavement improvements should be prioritized for municipalities and road maintenance engineers and will form a basis for the urban road management system.展开更多
[Objective] The research aimed to analyze the variation trend of temperature in Xingtai area in recent 48 years.[Method] According to the yearly and monthly average temperature data during 1963-2010 in Xingtai,Nangong...[Objective] The research aimed to analyze the variation trend of temperature in Xingtai area in recent 48 years.[Method] According to the yearly and monthly average temperature data during 1963-2010 in Xingtai,Nangong,Shahe and Neiqiu,the change trend of temperature in Xingtai area in recent 48 years was analyzed by using the line chart and trend chart of interannual variation average temperature,climate variability.[Result] The variation trends of annual average temperature,annual average maximum temperature,annual average minimum temperature and average temperatures in spring,summer,autumn,winter in Xingtai area in recent 48 years all presented the roughly same characteristics,which yearly rose.It embodied the climatic characteristics of global warming.The rise of annual mean temperature was because that the minimum temperature and winter average temperature rose.The continuous warm winter played the decisive role for the rise of annual average temperature.[Conclusion] The research provided the theoretical basis for understanding the variation characteristics of climate in Xingtai area under the climate warming background.展开更多
[Objective] The research aimed to analyze variation trend of sunshine hours in Xingtai area in recent 40 years.[Method] Based on yearly and seasonal total sunshine hours in Xingtai,Shahe and Neiqiu during 1971-2010,th...[Objective] The research aimed to analyze variation trend of sunshine hours in Xingtai area in recent 40 years.[Method] Based on yearly and seasonal total sunshine hours in Xingtai,Shahe and Neiqiu during 1971-2010,the change characteristics of annual and seasonal sunshine hours were analyzed by using line chart,trend chart and climatic variability.[Result] The annual sunshine hours in Xingtai,Shahe and Neiqiu during 1971-2010 all showed systemic decrease tendency.The three-station average decrease velocity was 77.7 h/10 a.The decrease in Xingtai was the most significant.The second one was Neiqiu.The total sunshine hours of three stations in spring,summer,autumn and winter all presented systemic decrease tendency.The decrease of Xingtai was the most significant.The three-station average decrease rates in spring,summer,autumn and winter were respectively 10.7,18.7,21.6 and 26.6 h/10 a.Whether the annual or seasonal total sunshine hours,the decrease of Xingtai was the most significant,reflecting urban turbidity island effect feature.In the case of three-station mean in 40 years,the total sunshine hours in winter,spring,summer and autumn were respectively 485.5,691.4,631.7 and 551.1 h.It illustrated that spring sunshine was the most enough and was followed by summer sunshine.The gas blanket in winter was stable,and the sunshine hours were the fewest.The main reason of sunshine hours decrease was urbanization development and aggravation of pollutant discharge.[Conclusion] The research provided scientific basis for reasonably using agricultural climate resources,improving ecological environment and promoting development of agricultural economy.展开更多
This study was conducted to examine the worldwide interest in the clean energy industry and to make recommendations for the development of this industry. The authors conducted a survey and research using Internet open...This study was conducted to examine the worldwide interest in the clean energy industry and to make recommendations for the development of this industry. The authors conducted a survey and research using Internet open source data in informatics methods to produce relevant results to support the depth of related work. Based on the valid findings, a discussion is carried out to give suggestions for the development of the clean energy industry in China at several levels.展开更多
基金National Natural Science Foundation of China(No.51605482)
文摘Fault prognosis is one of the key techniques for prognosis and health management,and an effective fault feature can improve prediction accuracy and performance. A novel approach of feature extraction for fault prognosis based on fault trend analysis was proposed in this paper. In order to describe the ability of tracking fault growth process,definitions and calculations of fault trackability was developed, and the feature which had the maximum fault trackability was selected for fault prognosis. The vibration data in bearing life tests were used to verify the effectiveness of the method was proposed. The results showed that the trackability of energy entropy for bearing fault growth was the maximum,and it was the best fault feature among selected features root mean square( RMS),kurtosis,new moment and energy entropy. The proposed approach can provide a better strategy for fault feature extraction of bearings in order to improve prediction accuracy.
基金funded partly by University of Zabol under Grant Number UOZ-GR-9616-145.
文摘Effective disturbance indices for Hyrcanian forests in Kheyroud,Nowshahr,Iran were determined.The study area was divided into landscape mosaics based on ecosystem parameters including profile type,slope and elevation.Co-occurrence texture indices were derived as forest disturbance factors on the first five bands of Landsat TM,ETM+and OLI images for the prevailing wood harvest disturbance regimes.These indices were screened using ten types of trend analyses and used for modeling disturbance of the harvesting regime through artificial neural networks.The results show that the selected indices can be useful in distinguishing areas with different disturbance intensities and as such,used in the context of health assessment through the health distance method.The accuracy of the health maps derived from the indices[increasing disturbance]led to give rise higher disturbance classification accuracy.
基金supported by grants from Fundacao de Amparo à Pesquisa do Estado do Rio de Janeiro-FAPERJ [E-26/2014-202.008]Conselho Nacional de Desenvolvimento Científico e Tecnológico–CNPq [302401/2016-4]
文摘Background: Currently, surgical resection represents the only curative treatment for pancreatic cancer(PC), however, the majority of tumors are no longer resectable by the time of diagnosis. The aim of this study was to describe time trends and distribution of pancreaticoduodenectomies(PDs) performed for treating PC in Brazil in recent years. Methods: Data were retrospectively obtained from Brazilian Health Public System(namely DATASUS) regarding hospitalizations for PC and PD in Brazil from January 2008 to December 2015. PC and PD rates and their mortalities were estimated from DATASUS hospitalizations and analyzed for age, gender and demographic characteristics. Results: A total of 2364 PDs were retrieved. Albeit PC incidence more than doubled, the number of PDs increased only 37%. Most PDs were performed in men(52.2%) and patients between 50 and 69 years old(59.5%). Patients not surgically treated and those 70 years or older had the highest in-hospital mortality rates. The most developed regions(Southeast and South) as well as large metropolitan integrated municipalities registered 76.2% and 54.8% of the procedures, respectively. LMIM PD mortality fluctuated, ranging from 13.6% in 2008 to 11.8% in 2015. Conclusions: This study suggests a trend towards regionalization and volume-outcome relationships for PD due to PC, as large metropolitan integrated municipalities registered most of the PDs and more stable mortality rates. The substantial differences between PD and PC increasing rates reveals a limiting step on the health system resoluteness. Reduction in the number of hospital beds and late access to hospitalization, despite improvement in diagnostic methods, could at least in part explain these findings.
基金supported by the National Natural Science Foundation of China (Grant Nos.41941010,41771064 and 41776195)the National Basic Research Program of China (Grant No.2016YFC1400303)the Basic Fund of the Chinese Academy of Meteorological Sciences (Grant No.2018Z001)。
文摘Long-term,ground-based daily global solar radiation (DGSR) at Zhongshan Station in Antarctica can quantitatively reveal the basic characteristics of Earth’s surface radiation balance and validate satellite data for the Antarctic region.The fixed station was established in 1989,and conventional radiation observations started much later in 2008.In this study,a random forest (RF) model for estimating DGSR is developed using ground meteorological observation data,and a highprecision,long-term DGSR dataset is constructed.Then,the trend of DGSR from 1990 to 2019 at Zhongshan Station,Antarctica is analyzed.The RF model,which performs better than other models,shows a desirable performance of DGSR hindcast estimation with an R^2 of 0.984,root-mean-square error of 1.377 MJ m^(-2),and mean absolute error of 0.828 MJ m^(-2).The trend of DGSR annual anomalies increases during 1990–2004 and then begins to decrease after 2004.Note that the maximum value of annual anomalies occurs during approximately 2004/05 and is mainly related to the days with precipitation (especially those related to good weather during the polar day period) at this station.In addition to clouds and water vapor,bad weather conditions (such as snowfall,which can result in low visibility and then decreased sunshine duration and solar radiation) are the other major factors affecting solar radiation at this station.The high-precision,longterm estimated DGSR dataset enables further study and understanding of the role of Antarctica in global climate change and the interactions between snow,ice,and atmosphere.
文摘Social media data created a paradigm shift in assessing situational awareness during a natural disaster or emergencies such as wildfire, hurricane, tropical storm etc. Twitter as an emerging data source is an effective and innovative digital platform to observe trend from social media users’ perspective who are direct or indirect witnesses of the calamitous event. This paper aims to collect and analyze twitter data related to the recent wildfire in California to perform a trend analysis by classifying firsthand and credible information from Twitter users. This work investigates tweets on the recent wildfire in California and classifies them based on witnesses into two types: 1) direct witnesses and 2) indirect witnesses. The collected and analyzed information can be useful for law enforcement agencies and humanitarian organizations for communication and verification of the situational awareness during wildfire hazards. Trend analysis is an aggregated approach that includes sentimental analysis and topic modeling performed through domain-expert manual annotation and machine learning. Trend analysis ultimately builds a fine-grained analysis to assess evacuation routes and provide valuable information to the firsthand emergency responders<span style="font-family:Verdana;">.</span>
文摘The purpose of this paper is to investigate the trend of precipitation in Kilkis region (Greece) at </span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">the </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">site and regional level in various time scales. At </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">the </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">site level, the precipitation trend was analyzed using three tests: 1) Mann</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Kendall, 2) Sen’s T and 3) Spearman while the trend slope was estimated using the Sen’s estimator. At </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">a </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">regional level, nonparametric spatial tests such as Regional Average Mann</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Kendall (RAMK) and BECD’s (Bootstrap Empirical Cumulative Distributions) were elaborated with and without the effect of cross correlation. The trend of precipitation was noticed generally downward at annual time scale and statistically significant at 5% level of significance only in only one station. The results of the analysis of trends at </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">the </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">regional level showed in total the influence of cross correlation in the time series since the number of trends detected is reduced when cross correlation is preserved. Precipitation data from 12 stations were used. The study results benefit water resource management, drought mitigation, socio-economic development, and sustainable agricultural planning </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">in </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">the region.
文摘This study aims at analyzing the tendency and change in the research on construction grammar from 2010 to 2020.Descriptively,this study includes the publication year,research topic,research direction,research content,and the research methods.Twenty-four CSSCI journals were selected as the research samples using the keyword–“Construction Grammar.”The research topics mainly include Chinese construction research,foreign language construction research,and comparative studies on Chinese and other language constructions.The results showed that there are many Chinese construction research,but the other two research topics still require improvement.Ontology research was the main focus;acquisition research and teaching research are worthy for further exploration.Case studies and theoretical studies were the most concerned contents,whereas studies on language acquisition,pedagogy,and corpus construction were feeble.Qualitative description and theoretical review were the most popular methods,while empirical,quantitative,and diachronic analyses were less frequently used.After analyzing the trends,it has been predicted that the research on construction grammar would continue to heat up in the future,and there would be more research directions and contents along with diversified research methods.
文摘Background:Afghanistan is suffering from 40-year chronic conflicts,displacement,and demolition of its infrastructure.Afghanistan mortality survey 2010 shows nearly 46%of all deaths in the country were attributed to noncommunicable diseases(NCDs).In this study,we aimed to understand the differences in mortality and premature death due to NCDs by sex and the trend for the next 8 years.Methods:We applied trend analysis using the secondary data from the Institute for Health Metrics and Evaluation,Global Burden of Diseases 2019.The information on NCD mortality,NCD deaths attributed to its risk factors,NCD percent of total years lived with disability(YLDs)attribution to each risk factor extracted from this database from 2008 to 2019.We investigated the trend from 2008 to 2019 for the mentioned factors and then forecast their trends until 2030.Results:Our study shows that Afghanistan has had an increasing death number due to NCDs from 2008 to 2019(50%for both sexes)and this will reach nearly 54%by 2030.Currently,half of NCDs deaths are premature in Afghanistan.The mortality rate and prevalence of risk factors are higher among women.More than 70%of YLDs will be due to NCDs in Afghanistan till 2030.Five risk factors including high systolic blood pressure(28.3%),high body mass index(23.4%),high blood glucose(20.6%),high low-density lipoprotein cholesterol(16.3%),and smoking(12.3%)will have the highest contribution to NCDs death in 2030,respectively.Conclusions:In general,our study indicates that without any specific intervention to address NCDs in Afghanistan,not only the Sustainable Development Goal target for NCDs will not be met,but an increase in almost all risk factors prevalence,as well as NCD mortality,will be seen in Afghanistan.
文摘The aim of this study is to establish the prevailing conditions of changing climatic trends and change point dates in four selected meteorological stations of Uyo, Benin, Port Harcourt, and Warri in the Niger Delta region of Nigeria. Using daily or 24-hourly annual maximum series (AMS) data with the Indian Meteorological Department (IMD) and the modified Chowdury Indian Meteorological Department (MCIMD) models were adopted to downscale the time series data. Mann-Kendall (MK) trend and Sen’s Slope Estimator (SSE) test showed a statistically significant trend for Uyo and Benin, while Port Harcourt and Warri showed mild trends. The Sen’s Slope magnitude and variation rate were 21.6, 10.8, 6.00 and 4.4 mm/decade, respectively. The trend change-point analysis showed the initial rainfall change-point dates as 2002, 2005, 1988, and 2000 for Uyo, Benin, Port Harcourt, and Warri, respectively. These prove positive changing climatic conditions for rainfall in the study area. Erosion and flood control facilities analysis and design in the Niger Delta will require the application of Non-stationary IDF modelling.
基金supported by the National Natural Science Foundation of China (813 72907, 81472531, 81472595, 81672683, 81672688, 81772928)the Natural Science Foundation ofHunan Province (2015JJ1022, 2016JC2035)the Fundamental Research Funds of the Central South University (2014zzts066)
文摘The National Central Cancer Registry of China(NCCRC)updated their nationwide statistics of cancer incidence and mortality in China according to 2013 population-based cancer registration data(due to the time required for data collection,quality control and analysis,the latest cancer statistics available in China have a 3-year lag behind the current year).In this report,the NCCRC provides a comprehensive review of cancer incidence and mortality rates,as well as the statistics overall and by geographical area,cancer sites or age groups(Chen et al.,2017a).It shows that the burden of cancer
文摘Groundwater accounts for about half of the water use for irrigation in India.The fluctuation pattern of the groundwater level is examined by observing rainfall replenishment and monitoring wells.The southern part of Rajasthan has experienced abrupt changes in rainfall and has been highly dependent on groundwater over decades.This study presents the impact of over-dependence on groundwater usage for irrigation and other purposes,spatially and temporally.Hence,the objective of this study is to examine the groundwater level trend by using statistical analysis and geospatial technique.Rainfall factor was also studied in groundwater level fluctuation during 2009-2019.To analyze the influence of each well during recharge or withdrawal of groundwater,thiessien polygonswere generated from them.In the Jakham River basin,75 wells have been identified for water level trend study using the Mann-Kendall statistical test.The statistics of trend analysis show that 15%wells are experiencing water level decline in pre-monsoon,while very low percentage of wells have such trend during post-monsoon season.The average rate of water level decline is 0.245 m/a in pre-monsoon and 0.05 m/a in post-monsoon.The aquifer recharge potential is also decreasing by year.it is expected that such type of studies will help the policy makers to adopt advanced management practices to ensure sustainable groundwater resource management.
文摘Based on the monitoring data of precipitation and runoff series from 1953 to 2013 and groundwater exploitation from 1977 to 2013 in Jinghui Irrigation Area,especially the evolution of water resources during the growth period of main crops,the trend test of precipitation and runoff series was carried out by using Spearman rank correlation test and R/S analysis.The results showed that the annual mean precipitation and runoff and the growth period of main crops showed a downward trend,and the changes in the future were similar to those in the past;the amount of groundwater exploitation has not changed much,which is about 150 million m^3.The research results can provide scientific basis for efficient utilization and reasonable allocation of water resources in irrigation area,and provide technical support for the development of modern agriculture.
文摘[Objective] The changes trend of temperature and frost-free period in Xingtai in recent 53 years were studied.[Method] According to the climate data of Xingtai City and Nangong County in 1958-2010,the changes trend of the temperature,the first and the last frost day,and the frost-free days in Xingtai were studied.The characteristics of the changes of temperature and frost-free days in Xingtai in recent 53 years were studied.[Result] No matter in city or countryside,the annual average temperature was increasing.The climate tendency rates in Xingtai and Nangong were about 0.5 and 0.2 ℃/10 a respectively.Especially,since 1996,the annual average temperature increasing trend was about 1.0 ℃/10 a.The average temperature of the four seasons was also climbing and was similar to the increasing span of the annual average temperature.The annual average temperature increasing span was the largest in winter.And the increase of the annual average temperature in winter was the largest and the increase of the annual average temperature was caused by the increase of the average temperature in winter.The urban annual average temperature was obviously higher than that of the countryside,which reflected the characteristics of tropical island effect.No matter in the city or the countryside,the early frost day,final frost day and frost-free day showed same tendency,namely,the delay of early frost day,advance of final-frost day,extension of frost-free day;the day of urban early frost was late than that of the countryside,and the final frost day was earlier than that of the countryside,the frost-free days were longer than that of countryside and indirectly influenced by urban heat effect.[Conclusion] The study provided theoretical basis for the development and application of thermal resources in Xingtai.
文摘[Objective] The research aimed to analyze the variation trend of rainfall in Xingtai area of Hebei Province in recent 48 years. [Method] According to the annual and seasonal rainfall data in Xingtai, Nangong, Shahe and Neiqiu during 1963-2010, by using the interannual variation rainfall line chart, trend chart and climatic variability, the variation trend of rainfall in Xingtai area in recent 48 years was analyzed. [Result] The annual rainfall in Xingtai area during 1963-2010 presented yearly decrease trend, and the decrease velocity was 18.0 mm/10 a. The annual rainfall in Xingtai, Nangong, Shahe and Neiqiu roughly presented same trend (linear decrease). Except spring rainfall in Xingtai area in recent 48 years slightly increased, the rainfall in summer, autumn and winter all presented linear decrease trend. The decrease velocity of summer rainfall was the maximum. The decrease of summer rainfall played decisive role in rainfall decrease of the whole year. The decrease trend of winter rainfall wasn't as significant as that of autumn rainfall. [Conclusion] The research provided theoretical basis for studying climatic variation characteristics in Xingtai area under the climatic warming background.
文摘Trend and stationarity analysis of climatic variables are essential for understanding climate variability and provide useful information about the vulnerability and future changes,especially in arid and semi-arid regions.In this study,various climatic zones of Iran were investigated to assess the relationship between the trend and the stationarity of the climatic variables.The Mann-Kendall test was considered to identify the trend,while the trend free pre-whitening approach was applied for eliminating serial correlation from the time-series.Meanwhile,time series stationarity was tested by Dickey-Fuller and Kwiatkowski-Phillips-Schmidt-Shin tests.The results indicated an increasing trend for mean air temperature series at most of the stations over various climatic zones,however,after eliminating the serial correlation factor,this increasing trend changes to an insignificant decreasing trend at a 95%confidence level.The seasonal mean air temperature trend suggested a significant increase in the majority of the stations.The mean air temperature increased more in northwest towards central parts of Iran that mostly located in arid and semiarid climatic zones.Precipitation trend reveals an insignificant downward trend in most of the series over various climatic zones;furthermore,most of the stations follow a decreasing trend for seasonal precipitation.Furthermore,spatial patterns of trend and seasonality of precipitation and mean air temperature showed that the northwest parts of Iran and margin areas of the Caspian Sea are more vulnerable to the changing climate with respect to the precipitation shortfalls and warming.Stationarity analysis indicated that the stationarity of climatic series influences on their trend;so that,the series which have significant trends are not static.The findings of this investigation can help planners and policy-makers in various fields related to climatic issues,implementing better management and planning strategies to adapt to climate change and variability over Iran.
文摘Pavement roughness(IRI—International Roughness Index values)influence the stability of traffic movements both on intercity roads and urban roads.This study is to determine the exact locations of critical pavement roughness values that affect traffic motion stability and comfort in city centre highway arteries.Roughness data with 10 m intervals were collected on a 3140 m divided road containing three consecutive signalized intersections in the city centre arterial.These data were analysed using the distance-dependent Mann-Kendall trend analysis method and checkerboard model.The sections where roughness is important were determined at a 95%confidence interval.The results will show where future pavement improvements should be prioritized for municipalities and road maintenance engineers and will form a basis for the urban road management system.
文摘[Objective] The research aimed to analyze the variation trend of temperature in Xingtai area in recent 48 years.[Method] According to the yearly and monthly average temperature data during 1963-2010 in Xingtai,Nangong,Shahe and Neiqiu,the change trend of temperature in Xingtai area in recent 48 years was analyzed by using the line chart and trend chart of interannual variation average temperature,climate variability.[Result] The variation trends of annual average temperature,annual average maximum temperature,annual average minimum temperature and average temperatures in spring,summer,autumn,winter in Xingtai area in recent 48 years all presented the roughly same characteristics,which yearly rose.It embodied the climatic characteristics of global warming.The rise of annual mean temperature was because that the minimum temperature and winter average temperature rose.The continuous warm winter played the decisive role for the rise of annual average temperature.[Conclusion] The research provided the theoretical basis for understanding the variation characteristics of climate in Xingtai area under the climate warming background.
文摘[Objective] The research aimed to analyze variation trend of sunshine hours in Xingtai area in recent 40 years.[Method] Based on yearly and seasonal total sunshine hours in Xingtai,Shahe and Neiqiu during 1971-2010,the change characteristics of annual and seasonal sunshine hours were analyzed by using line chart,trend chart and climatic variability.[Result] The annual sunshine hours in Xingtai,Shahe and Neiqiu during 1971-2010 all showed systemic decrease tendency.The three-station average decrease velocity was 77.7 h/10 a.The decrease in Xingtai was the most significant.The second one was Neiqiu.The total sunshine hours of three stations in spring,summer,autumn and winter all presented systemic decrease tendency.The decrease of Xingtai was the most significant.The three-station average decrease rates in spring,summer,autumn and winter were respectively 10.7,18.7,21.6 and 26.6 h/10 a.Whether the annual or seasonal total sunshine hours,the decrease of Xingtai was the most significant,reflecting urban turbidity island effect feature.In the case of three-station mean in 40 years,the total sunshine hours in winter,spring,summer and autumn were respectively 485.5,691.4,631.7 and 551.1 h.It illustrated that spring sunshine was the most enough and was followed by summer sunshine.The gas blanket in winter was stable,and the sunshine hours were the fewest.The main reason of sunshine hours decrease was urbanization development and aggravation of pollutant discharge.[Conclusion] The research provided scientific basis for reasonably using agricultural climate resources,improving ecological environment and promoting development of agricultural economy.
文摘This study was conducted to examine the worldwide interest in the clean energy industry and to make recommendations for the development of this industry. The authors conducted a survey and research using Internet open source data in informatics methods to produce relevant results to support the depth of related work. Based on the valid findings, a discussion is carried out to give suggestions for the development of the clean energy industry in China at several levels.
