This paper presents the calibration of Omori’s aftershock occurrence rate model for Turkey and the resulting likelihoods.Aftershock occurrence rate models are used for estimating the probability of an aftershock that...This paper presents the calibration of Omori’s aftershock occurrence rate model for Turkey and the resulting likelihoods.Aftershock occurrence rate models are used for estimating the probability of an aftershock that exceeds a specific magnitude threshold within a time interval after the mainshock.Critical decisions on the post-earthquake safety of structures directly depend on the aftershock hazard estimated using the occurrence model.It is customary to calibrate models in a region-specific manner.These models depend on rate parameters(a,b,c and p)related to the seismicity characteristics of the investigated region.In this study,the available well-recorded aftershock sequences for a set of Mw≥5.9 mainshock events that were observed in Turkey until 2012 are considered to develop the aftershock occurrence model.Mean estimates of the model parameters identified for Turkey are a=-1.90,b=1.11,c=0.05 and p=1.20.Based on the developed model,aftershock likelihoods are computed for a range of different time intervals and mainshock magnitudes.Also,the sensitivity of aftershock probabilities to the model parameters is investigated.Aftershock occurrence probabilities estimated using the model are expected to be useful for post-earthquake safety evaluations in Turkey.展开更多
This work aimed to construct an epidemic model with fuzzy parameters.Since the classical epidemic model doesnot elaborate on the successful interaction of susceptible and infective people,the constructed fuzzy epidemi...This work aimed to construct an epidemic model with fuzzy parameters.Since the classical epidemic model doesnot elaborate on the successful interaction of susceptible and infective people,the constructed fuzzy epidemicmodel discusses the more detailed versions of the interactions between infective and susceptible people.Thenext-generation matrix approach is employed to find the reproduction number of a deterministic model.Thesensitivity analysis and local stability analysis of the systemare also provided.For solving the fuzzy epidemic model,a numerical scheme is constructed which consists of three time levels.The numerical scheme has an advantage overthe existing forward Euler scheme for determining the conditions of getting the positive solution.The establishedscheme also has an advantage over existing non-standard finite difference methods in terms of order of accuracy.The stability of the scheme for the considered fuzzy model is also provided.From the plotted results,it can beobserved that susceptible people decay by rising interaction parameters.展开更多
The Chinese Loess Plateau is the most seriously eroded area in the world and contributes the vast majority of the sediment that goes into the Yellow River.Since the 1950s,progressive soil and water conservation measur...The Chinese Loess Plateau is the most seriously eroded area in the world and contributes the vast majority of the sediment that goes into the Yellow River.Since the 1950s,progressive soil and water conservation measures have been implemented—in particular,large-scale ecological restoration has been ongoing since 1999—resulting in a significant reduction of the sediment load.However,the mechanism of the sediment transport dynamics is not fully understood due to multiple and complicated influencing factors including climate change and human activities(e.g.,ecological restoration).A challenging question,then,arises:Is the current low sediment level a“new normal”in this era and in the future?To address this question,we selected a typical loess hilly region where considerable ecological restoration has been implemented,and which is regarded as the site of the first and most representative Grainfor-Green program in the Loess Plateau.We investigated the evolution of discharge–sediment relationships in the past decades(1960–2010)and their association with the soil and water conservation measures in this area.The results showed that there was a distinct change in the regression parameters of the commonly used annual discharge–sediment regression equation—a continuously increasing trend of parameter b and a decreasing trend of parameter a,accompanying the ecological restoration.The increase in exponent b(i.e.,a steeper slope)implies a potential lower sediment load resulting from low discharge and a potential higher sediment load resulting from large discharge.This finding may question the new normal of a low sediment level and implies the potential risk of a large sediment load during extremely wet years.展开更多
To explore the relation of maize grain texture and phenotypic traits with grain thin-layer drying rate,we observed the ultra-structure of maize grain,and tested three traits about the maize grain texture and four phen...To explore the relation of maize grain texture and phenotypic traits with grain thin-layer drying rate,we observed the ultra-structure of maize grain,and tested three traits about the maize grain texture and four phenotypic traits.The vitreous part percentage was different（P〈0.05） among different maize inbred lines.There was a significant relationship between the drying rate with grain texture and phenotypic traits.Main factors that influenced the drying rate were different during different drying stages.New results observed that empirical constants（k and N） in drying equation were different for seed of the 30 inbred lines of maize.The k of simplified diffusion equation and N of page equation were significantly influenced by both grain texture and phenotypic traits.These results could be used as guideline parameters for drying maize seeds having different grain characteristics during different drying stages.展开更多
We propose a nonparametric change point estimator in the distributions of a sequence of independent observations in terms of the test statistics given by Huˇskov′a and Meintanis(2006) that are based on weighted empi...We propose a nonparametric change point estimator in the distributions of a sequence of independent observations in terms of the test statistics given by Huˇskov′a and Meintanis(2006) that are based on weighted empirical characteristic functions. The weight function ω(t; a) under consideration includes the two weight functions from Huˇskov′a and Meintanis(2006) plus the weight function used by Matteson and James(2014),where a is a tuning parameter. Under the local alternative hypothesis, we establish the consistency, convergence rate, and asymptotic distribution of this change point estimator which is the maxima of a two-side Brownian motion with a drift. Since the performance of the change point estimator depends on a in use, we thus propose an algorithm for choosing an appropriate value of a, denoted by a_s which is also justified. Our simulation study shows that the change point estimate obtained by using a_s has a satisfactory performance. We also apply our method to a real dataset.展开更多
In this paper the meteorological background for the formation of plume from the forest fire in Northeast China on 7—8 May 1987 is stated.The long-range instantaneous diffusion parameters are calculated by using the s...In this paper the meteorological background for the formation of plume from the forest fire in Northeast China on 7—8 May 1987 is stated.The long-range instantaneous diffusion parameters are calculated by using the satellite photograph of the plumes with visible length ranging from 100 to over 500 kin.The results of cal- culation show that the relations between instantaneous diffusion parameter and travel time(up to 60000 sec.) obey the law of linear or 3/2 power.In addition,heat release from the fire on May 7—8 estimated by puff rising formula can meet,in respect to the order of magnitude,the value gained on the field survey.展开更多
基金Supported by:Scientific and Technological Research Council of Turkey(TUBITAK)with Grant No.213M454
文摘This paper presents the calibration of Omori’s aftershock occurrence rate model for Turkey and the resulting likelihoods.Aftershock occurrence rate models are used for estimating the probability of an aftershock that exceeds a specific magnitude threshold within a time interval after the mainshock.Critical decisions on the post-earthquake safety of structures directly depend on the aftershock hazard estimated using the occurrence model.It is customary to calibrate models in a region-specific manner.These models depend on rate parameters(a,b,c and p)related to the seismicity characteristics of the investigated region.In this study,the available well-recorded aftershock sequences for a set of Mw≥5.9 mainshock events that were observed in Turkey until 2012 are considered to develop the aftershock occurrence model.Mean estimates of the model parameters identified for Turkey are a=-1.90,b=1.11,c=0.05 and p=1.20.Based on the developed model,aftershock likelihoods are computed for a range of different time intervals and mainshock magnitudes.Also,the sensitivity of aftershock probabilities to the model parameters is investigated.Aftershock occurrence probabilities estimated using the model are expected to be useful for post-earthquake safety evaluations in Turkey.
基金the support of Prince Sultan University for paying the article processing charges(APC)of this publication.
文摘This work aimed to construct an epidemic model with fuzzy parameters.Since the classical epidemic model doesnot elaborate on the successful interaction of susceptible and infective people,the constructed fuzzy epidemicmodel discusses the more detailed versions of the interactions between infective and susceptible people.Thenext-generation matrix approach is employed to find the reproduction number of a deterministic model.Thesensitivity analysis and local stability analysis of the systemare also provided.For solving the fuzzy epidemic model,a numerical scheme is constructed which consists of three time levels.The numerical scheme has an advantage overthe existing forward Euler scheme for determining the conditions of getting the positive solution.The establishedscheme also has an advantage over existing non-standard finite difference methods in terms of order of accuracy.The stability of the scheme for the considered fuzzy model is also provided.From the plotted results,it can beobserved that susceptible people decay by rising interaction parameters.
基金funded by the Shaanxi Key Research and Development Program of China(2018ZDXM-GY-030)the National Thousand Youth Talent Program of China,the Hundred Youth Talent Program of Shaanxi Province,the Fundamental Research Funds for the Central Universities(xjj2018204)+3 种基金the Young Talent Support Plan of Xi’an Jiaotong University,the National Natural Science Foundation of China(31741020)the Postdoctoral Science Foundation of China(2016M592777)We are grateful to the editors and the reviewers for their constructive comments and suggestions to improve this paperWe also thank the HPCC Platform in Xi’an Jiaotong University for computing equipment and computer maintenance.
文摘The Chinese Loess Plateau is the most seriously eroded area in the world and contributes the vast majority of the sediment that goes into the Yellow River.Since the 1950s,progressive soil and water conservation measures have been implemented—in particular,large-scale ecological restoration has been ongoing since 1999—resulting in a significant reduction of the sediment load.However,the mechanism of the sediment transport dynamics is not fully understood due to multiple and complicated influencing factors including climate change and human activities(e.g.,ecological restoration).A challenging question,then,arises:Is the current low sediment level a“new normal”in this era and in the future?To address this question,we selected a typical loess hilly region where considerable ecological restoration has been implemented,and which is regarded as the site of the first and most representative Grainfor-Green program in the Loess Plateau.We investigated the evolution of discharge–sediment relationships in the past decades(1960–2010)and their association with the soil and water conservation measures in this area.The results showed that there was a distinct change in the regression parameters of the commonly used annual discharge–sediment regression equation—a continuously increasing trend of parameter b and a decreasing trend of parameter a,accompanying the ecological restoration.The increase in exponent b(i.e.,a steeper slope)implies a potential lower sediment load resulting from low discharge and a potential higher sediment load resulting from large discharge.This finding may question the new normal of a low sediment level and implies the potential risk of a large sediment load during extremely wet years.
基金funded by the Shandong Modern Agricultural Technology & Industry System,Chinathe Seed Production Technology and Development of Key Equipment and Demonstration(201203052) from Special Funds for Agro-scientific Research in the Public Interest,China+1 种基金the Maize Germplasm Innovation of Shandong Seed Industry Project,Chinathe Shandong Province Modern Agriculture Industrial Production Technology System,China (SDAIT-01-022-02)
文摘To explore the relation of maize grain texture and phenotypic traits with grain thin-layer drying rate,we observed the ultra-structure of maize grain,and tested three traits about the maize grain texture and four phenotypic traits.The vitreous part percentage was different（P〈0.05） among different maize inbred lines.There was a significant relationship between the drying rate with grain texture and phenotypic traits.Main factors that influenced the drying rate were different during different drying stages.New results observed that empirical constants（k and N） in drying equation were different for seed of the 30 inbred lines of maize.The k of simplified diffusion equation and N of page equation were significantly influenced by both grain texture and phenotypic traits.These results could be used as guideline parameters for drying maize seeds having different grain characteristics during different drying stages.
基金supported by Natural Sciences and the Engineering Research Council of Canada (Grant No. 105557-2012)National Natural Science Foundation for Young Scientists of China (Grant No. 11201108)+1 种基金the National Statistical Research Plan Project (Grant No. 2012LZ009)the Humanities and Social Sciences Project from Ministry of Education of China (Grant No. 12YJC910007)
文摘We propose a nonparametric change point estimator in the distributions of a sequence of independent observations in terms of the test statistics given by Huˇskov′a and Meintanis(2006) that are based on weighted empirical characteristic functions. The weight function ω(t; a) under consideration includes the two weight functions from Huˇskov′a and Meintanis(2006) plus the weight function used by Matteson and James(2014),where a is a tuning parameter. Under the local alternative hypothesis, we establish the consistency, convergence rate, and asymptotic distribution of this change point estimator which is the maxima of a two-side Brownian motion with a drift. Since the performance of the change point estimator depends on a in use, we thus propose an algorithm for choosing an appropriate value of a, denoted by a_s which is also justified. Our simulation study shows that the change point estimate obtained by using a_s has a satisfactory performance. We also apply our method to a real dataset.
文摘In this paper the meteorological background for the formation of plume from the forest fire in Northeast China on 7—8 May 1987 is stated.The long-range instantaneous diffusion parameters are calculated by using the satellite photograph of the plumes with visible length ranging from 100 to over 500 kin.The results of cal- culation show that the relations between instantaneous diffusion parameter and travel time(up to 60000 sec.) obey the law of linear or 3/2 power.In addition,heat release from the fire on May 7—8 estimated by puff rising formula can meet,in respect to the order of magnitude,the value gained on the field survey.
