This paper mainly studies the influence maximization problem of threshold models in hypergraphs,which aims to identify the most influential nodes in hypergraphs.Firstly,we introduce a novel information diffusion rule ...This paper mainly studies the influence maximization problem of threshold models in hypergraphs,which aims to identify the most influential nodes in hypergraphs.Firstly,we introduce a novel information diffusion rule in hypergraphs based on Threshold Models and conduct the stability analysis.Then we extend the CI-TM algorithm,originally designed for complex networks,to hypergraphs,denoted as the H-CI-TM algorithm.Secondly,we use an iterative approach to get the globally optimal solutions.The analysis reveals that our algorithm ultimately identifies the most influential set of nodes.Based on the numerical simulations,HCI-TM algorithm outperforms several competing algorithms in both synthetic and real-world hypergraphs.Essentially,when provided with the same number of initial seeds,our algorithm can achieve a larger activation size.Our method not only accurately assesses the influence of individual nodes but also identifies a set of nodes with greater impact.Furthermore,our results demonstrate good scalability when handling intricate relationships and large-scale hypergraphs.The outcomes of our research provide substantial support for the applications of the threshold models across diverse fields,including social network analysis and marketing strategies.展开更多
The authors are to be congratulated for an innovative paper in terms of both modelling methodology and subject matter significance. The analysis of short time series is known to be
This is a very attractive article. It combines fascinating new methodology with a most interesting dataset, and a highly motivating presentation. However, despite the many
-In this paper, monthly mean SST data in a large area are used. After the spacial average of the data is carried out and the secular monthly means are substracted, a time series (Jan. 1951-Dec. 1985) of SST anomalies ...-In this paper, monthly mean SST data in a large area are used. After the spacial average of the data is carried out and the secular monthly means are substracted, a time series (Jan. 1951-Dec. 1985) of SST anomalies of the cold tongue water area in the eastern tropical Pacific Ocean is obtained. On the basis of the time series, an autoregression model, a self-exciting threshold autoregression model and an open loop autoregression model are developed respectively. The interannual variations are simulated by means of those models. The simulation results show that all the three models have made very good hindcasting for the nine El Nino events since 1951. In order to test the reliability of the open loop threshold model, extrapolated forecast was made for the period of Jan. 1986-Feb. 1987. It can be seen from the forecasting that the model could forecast well the beginning and strengthening stages of the recent El Nino event (1986-1987). Correlation coefficients of the estimations to observations are respectively 0. 84, 0. 88 and 0. 89. It is obvious that all the models work well and the open loop threshold one is the best. So the open loop threshold autoregression model is a useful tool for monitoring the SSTinterannual variation of the cold tongue water area in the Eastern Equatorial Pacific Ocean and for estimating the El Nino strength.展开更多
In clinical research,subgroup analysis can help identify patient groups that respond better or worse to specific treatments,improve therapeutic effect and safety,and is of great significance in precision medicine.This...In clinical research,subgroup analysis can help identify patient groups that respond better or worse to specific treatments,improve therapeutic effect and safety,and is of great significance in precision medicine.This article considers subgroup analysis methods for longitudinal data containing multiple covariates and biomarkers.We divide subgroups based on whether a linear combination of these biomarkers exceeds a predetermined threshold,and assess the heterogeneity of treatment effects across subgroups using the interaction between subgroups and exposure variables.Quantile regression is used to better characterize the global distribution of the response variable and sparsity penalties are imposed to achieve variable selection of covariates and biomarkers.The effectiveness of our proposed methodology for both variable selection and parameter estimation is verified through random simulations.Finally,we demonstrate the application of this method by analyzing data from the PA.3 trial,further illustrating the practicality of the method proposed in this paper.展开更多
Irregular seismic data causes problems with multi-trace processing algorithms and degrades processing quality. We introduce the Projection onto Convex Sets （POCS） based image restoration method into the seismic data...Irregular seismic data causes problems with multi-trace processing algorithms and degrades processing quality. We introduce the Projection onto Convex Sets （POCS） based image restoration method into the seismic data reconstruction field to interpolate irregularly missing traces. For entire dead traces, we transfer the POCS iteration reconstruction process from the time to frequency domain to save computational cost because forward and reverse Fourier time transforms are not needed. In each iteration, the selection threshold parameter is important for reconstruction efficiency. In this paper, we designed two types of threshold models to reconstruct irregularly missing seismic data. The experimental results show that an exponential threshold can greatly reduce iterations and improve reconstruction efficiency compared to a linear threshold for the same reconstruction result. We also analyze the anti- noise and anti-alias ability of the POCS reconstruction method. Finally, theoretical model tests and real data examples indicate that the proposed method is efficient and applicable.展开更多
Global population aging trends are intensifying,presenting multifaceted economic and social challenges for countries worldwide.As the world’s largest developing country,China has entered a phase of extreme demographi...Global population aging trends are intensifying,presenting multifaceted economic and social challenges for countries worldwide.As the world’s largest developing country,China has entered a phase of extreme demographic aging,posing significant questions about its impact on the ongoing upgrading of industrial structures.How does this demographic shift influence the upgrading of industrial structures,and does technological innovation mitigate or exacerbate this impact?The empirical results indicate that population aging impedes upgrading the industrial structure,while technological innovation positively affects the relationship between the two.Moreover,using technological innovation as a threshold variable,the impact of population aging on industrial structure upgrading evolves in a“gradient”manner from“impediment”to“insignificant”to“promotion”as the technological innovation levels increase.These findings offer practical guidance for tailoring industrial policies to different stages of technological advancement.展开更多
To avoid missing track caused by the target maneuvers in automatic target tracking system, a new maneuvering target tracking technique called threshold interacting multiple model （TIMM） is proposed. This algorithm i...To avoid missing track caused by the target maneuvers in automatic target tracking system, a new maneuvering target tracking technique called threshold interacting multiple model （TIMM） is proposed. This algorithm is based on the interacting multiple model （IMM） method and applies a threshold controller to improve tracking accuracy. It is also applicable to other advanced algorithms of IMM. In this research, we also compare the position and velocity root mean square （RMS） errors of TIMM and IMM algorithms with two different examples. Simulation results show that the TIMM algorithm is superior to the traditional IMM alzorithm in estimation accuracy.展开更多
The subset threshold auto regressive (SSTAR) model, which is capable of reproducing the limit cycle behavior of nonlinear time series, is introduced. The algorithm for fitting the sampled data with SSTAR model is pr...The subset threshold auto regressive (SSTAR) model, which is capable of reproducing the limit cycle behavior of nonlinear time series, is introduced. The algorithm for fitting the sampled data with SSTAR model is proposed and applied to model and forecast power load. Numerical example verifies that desirable accuracy of short term load forecasting can be achieved by using the SSTAR model.展开更多
Longevity and stay ability are parameters in any breeding programme. </span><span style="font-family:Verdana;">The </span><span style="font-family:Verdana;">Overstaying of a...Longevity and stay ability are parameters in any breeding programme. </span><span style="font-family:Verdana;">The </span><span style="font-family:Verdana;">Overstaying of any animal </span><span style="font-family:Verdana;">o</span><span style="font-family:Verdana;">n a farm has got negative effects </span><span style="font-family:Verdana;">on</span><span style="font-family:Verdana;"> the farmer. Short stay also means early exit of good animal</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> that could have been used for a longer time and more productive. The intention of this review paper is to emphasize the importance of models that an upcoming breeding program can use without affecting the quality of the herd. In this paper</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> longevity is taken purely on </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">performance measure. The functional and type traits of longevity should be studied further before all models are put into play. But the case of closed breeding programmes, performance traits are easily measurable because many animals will exit the herd as they have been sold to farmers hence many functional straits will be expressed outside the herd. Genetic evaluation of the Kenyan Sahiwal should account for inbreeding. This study has also </span><span style="font-family:Verdana;">provided genetic and phenotypic parameters to enable </span></span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">inclusion of longevity in the breeding objective for the Sahiwal cattle improvement pro</span><span style="font-family:Verdana;">gramme.展开更多
A grain-based distinct element model featuring three-dimensional （3D） Voronoi tessellations （randompoly-crystals） is proposed for simulation of crack damage development in brittle rocks. The grainboundaries in pol...A grain-based distinct element model featuring three-dimensional （3D） Voronoi tessellations （randompoly-crystals） is proposed for simulation of crack damage development in brittle rocks. The grainboundaries in poly-crystal structure produced by Voronoi tessellations can represent flaws in intact rockand allow for numerical replication of crack damage progression through initiation and propagation ofmicro-fractures along grain boundaries. The Voronoi modelling scheme has been used widely in the pastfor brittle fracture simulation of rock materials. However the difficulty of generating 3D Voronoi modelshas limited its application to two-dimensional （2D） codes. The proposed approach is implemented inNeper, an open-source engine for generation of 3D Voronoi grains, to generate block geometry files thatcan be read directly into 3DEC. A series of Unconfined Compressive Strength （UCS） tests are simulated in3DEC to verify the proposed methodology for 3D simulation of brittle fractures and to investigate therelationship between each micro-parameter and the model＇s macro-response. The possibility of numericalreplication of the classical U-shape strength curve for anisotropic rocks is also investigated innumerical UCS tests by using complex-shaped （elongated） grains that are cemented to one another alongtheir adjoining sides. A micro-parameter calibration procedure is established for 3D Voronoi models foraccurate replication of the mechanical behaviour of isotropic and anisotropic （containing a fabric） rocks. 2014 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.展开更多
Species evolution is essentially a random process of interaction between biological populations and their environ- ments. As a result, some physical parameters in evolution models are subject to statistical fluctuatio...Species evolution is essentially a random process of interaction between biological populations and their environ- ments. As a result, some physical parameters in evolution models are subject to statistical fluctuations. In this work, two important parameters in the Eigen model, the fitness and mutation rate, are treated as Gaassian dis- tributed random variables simultaneously to examine the property of the error threshold. Numerical simulation results show that the error threshold in the fully random model appears as a crossover region instead of a phase transition point, and ＆s the fluctuation strength increases the crossover region becomes smoother and smoother. Furthermore, it is shown that the randomization of the mutation rate plays a dominant role in changing the error threshold in the fully random model, which is consistent with the existing experimental data. The implication of the threshold change due to the randomization for antiviral strategies is discussed.展开更多
Questions persist on the relationship between tourism dependence and economic growth in ethnic tourism areas.This study addresses such gaps by constructing a threshold regression model based on socio-economic data fro...Questions persist on the relationship between tourism dependence and economic growth in ethnic tourism areas.This study addresses such gaps by constructing a threshold regression model based on socio-economic data from 2006 to 2019 for nine sites in Enshi Prefecture of central China.Arc GIS and other open-source data were also used to visualize changing tourism resources in the region.Findings suggest that tourism dependence(the ratio of tourism-based GDP to overall GDP)significantly promotes economic growth in ethnic minority areas.However,the positive influence of tourism dependence on economic growth appears dynamic and non-linear–rising at first before falling when tourism dependence exceeded a threshold of 34%,with effects varying by site and year.Methods and findings make crucial theoretical contributions to understanding tourism dependence and poverty alleviation linkages.This paper also highlights the importance of political support and balanced investment in diverse industries to minimize decreasing returns beyond tourism dependence thresholds in destinations worldwide.展开更多
The innovations actually diffuse among social network nowadays.Individual heterogeneity,interactions between individuals and network topology influence a lot.We established a "double threshold" modified mode...The innovations actually diffuse among social network nowadays.Individual heterogeneity,interactions between individuals and network topology influence a lot.We established a "double threshold" modified model and took the number of neighbors,neighbors' adoption and the cost-benefit parameters as crucial influencing factors.The diffusion of DaLingTong(CDMA450)products in MeiShan city of SiChuan province during 2004 to 2007 has been used to verity the model on Matlab.The validation results fit the actual diffusion pattern of DaLingTong(CDMA450) products very well.The results indicate that there exists a "tipping point(threshold)" in the process of innovation diffusion.If the initial adoption quantity is larger than the tipping point,then the product will spread to a large portion of people,otherwise is will collapse to zero.The model can effectively predict the diffusion of new products,and can influence the diffusion process by changing the value of the parameters.展开更多
Large-strain deformations introduce several confounding factors that affect the application of the Mechanical Threshold Stress model. These include the decrease with the increasing stress of the normalized activation ...Large-strain deformations introduce several confounding factors that affect the application of the Mechanical Threshold Stress model. These include the decrease with the increasing stress of the normalized activation energy characterizing deformation kinetics, the tendency toward Stage IV hardening at high strains, and the influence of crystallographic texture. Minor additions to the Mechanical Threshold Stress model are introduced to account for variations of the activation energy and the addition of Stage IV hardening. Crystallographic texture cannot be modeled using an isotropic formulation, but some common trends when analyzing predominantly shear deformation followed by uniaxial deformation are described. Comparisons of model predictions with measurements in copper processed using Equal Channel Angular Pressing are described.展开更多
In the backdrop of“dual-carbon”strategic objectives,understanding the influence of the digital economy(DE)on carbon emissions(CEs)is imperative.However,there is limited research on the DE’s negative impact on CEs a...In the backdrop of“dual-carbon”strategic objectives,understanding the influence of the digital economy(DE)on carbon emissions(CEs)is imperative.However,there is limited research on the DE’s negative impact on CEs and the nonlinear relationship between the DE and CE.To address this gap,we collected data from 270 Chinese cities from 2011 to 2021 and used benchmark regression,mediated effects,and panel threshold models to explore the DE’s impact on CEs.The results showed that DE had a nonlinear,inverted U-shaped effect on CEs,with CEs initially increasing and then being suppressed.This conclusion remained consistent even after a series of robustness tests.Overall,the rate of urbanization and breadth of digital financial coverage mediate the relationship between the DE and CEs.Additionally,the combined effects of economic development,environmental regulation,fiscal decentralization,and population size contribute to the DE’s nonlinear impact on CEs.The impact of the DE on CEs varies among nonresource-based,resource-based,and resource-depleted cities and between urban and nonurban agglomerations.This paper’s findings support the development of the DE and the formulation of CE reduction policies.展开更多
Economic growth and environmental pollution have become the bases of geopolitical competition due to the multiple constraints of growth in energy consumption and environmental protection in recent decades.Whether the ...Economic growth and environmental pollution have become the bases of geopolitical competition due to the multiple constraints of growth in energy consumption and environmental protection in recent decades.Whether the coordinated development of inward foreign direct investment(IFDI)and outward foreign direct investment(OFDI)promote economic growth while reducing environmental pollution and realizing high-quality development affects the overall socialist modernization under China’s“Dual Circulation”policy.Using China’s provincial panel data from 2005 to 2020,this paper first measured green total factor productivity(GTFP)and the coordinated development index(CDIFDI)of IFDI and OFDI via the slacks-based measureglobal Malmquist–Luenberger(SBM-GML)model and the capacity coupling model.A panel threshold model with interactive effects(PTIFEs)was then applied to explore the nonlinear impact of the CDIFDI on China’s GTFP.Finally,a regional heterogeneity analysis was conducted for China’s eastern,central and western regions of China.Results show that(1)GTFP in China kept rising with small fluctuations during the sample period,with the increasing range of GTFP decreasing from east to west.(2)CDIFDI had a significant“U”-shaped threshold effect on GTFP,and the main threshold variables were the industrial structure and the level of economic development.(3)CDIFDI played a positive role in promoting GTFP growth in the eastern region,while the effects of CDIFDI on GTFP in the central and western regions were not significant.Policy-makers and enterprises should comprehensively consider promoting regional industrial upgrading and economic growth to achieve a greater positive impact of CDIFDI on GTFP.Scientifically measuring GTFP and exploring the nonlinear impact of the CDIFDI on GTFP and regional heterogeneity provide helpful references for policy-makers to coordinate the high-quality development of regional economies.展开更多
The efficiency, precision, and denoising capabilities of reconstruction algorithms are critical to seismic data processing. Based on the Fourier-domain projection onto convex sets （POCS） algorithm, we propose an inv...The efficiency, precision, and denoising capabilities of reconstruction algorithms are critical to seismic data processing. Based on the Fourier-domain projection onto convex sets （POCS） algorithm, we propose an inversely proportional threshold model that defines the optimum threshold, in which the descent rate is larger than in the exponential threshold in the large-coefficient section and slower than in the exponential threshold in the small-coefficient section. Thus, the computation efficiency of the POCS seismic reconstruction greatly improves without affecting the reconstructed precision of weak reflections. To improve the flexibility of the inversely proportional threshold, we obtain the optimal threshold by using an adjustable dependent variable in the denominator of the inversely proportional threshold model. For random noise attenuation by completing the missing traces in seismic data reconstruction, we present a weighted reinsertion strategy based on the data-driven model that can be obtained by using the percentage of the data-driven threshold in each iteration in the threshold section. We apply the proposed POCS reconstruction method to 3D synthetic and field data. The results suggest that the inversely proportional threshold model improves the computational efficiency and precision compared with the traditional threshold models; furthermore, the proposed reinserting weight strategy increases the SNR of the reconstructed data.展开更多
This paper uses inter-provincial panel data from 2011 to 2017,a linear regression model,and a threshold model to conduct empirical analyses of the impact of the digital economy on China's overall economic growth a...This paper uses inter-provincial panel data from 2011 to 2017,a linear regression model,and a threshold model to conduct empirical analyses of the impact of the digital economy on China's overall economic growth and the three main sectors of industry.The paper then investigates the impact and effects the digital economy has had on the economic growth of the three main sectors of industry in China's eastern,central,and western regions.Finally,the paper investigates the most significant differences among the various regions and the threshold effects of urbanization levels on the relationship between the digital economy and economic growth.The findings indicate a significantly positive correlation between the digital economy and regional economic growth.Moreover,geographical factors notably influence this correlation.The digital economy exerts a positive effect on all sectors of industry.It may not substantially impact industrial development in regions with highly developed infrastructure.Regarding the other regions,the digital economy exhibits varying degrees of impact due to the differences in the specific indicators.The conclusion drawn by the threshold model is that the magnitude of the threshold effect correlates with geographic factors.No threshold effect was observed in the eastern region,while the threshold effect occurred in the central region when the urbanization levels for the provinces were below 0.6645.Similarly,the threshold effect was noted in the western region when the urbanization level was below 0.3931.Considering all of this,the study also offers policy recommendations that will help balance the regional development of digital economies,accelerate the digital transformation of traditional industries,enhance digital infrastructure construction,refine the formulation and implementation of data policy,and establish relevant incentive mechanisms.展开更多
Scholars have a variety of theoretical explanations for housing price growth. However, few scholars have studied the internal influence mechanism among urbanization, land finance, and housing price. Based on the data ...Scholars have a variety of theoretical explanations for housing price growth. However, few scholars have studied the internal influence mechanism among urbanization, land finance, and housing price. Based on the data of 182 prefecture-level cities from 2009 to 2016, this paper studies the influence of land finance on housing price under different urbanization rate levels. The study finds that with the increase of urbanization rate, the effect of land finance on housing price presents a "U" shape.Specifically, an increase in land finance by 1% results in a corresponding increase in average housing price by 0.18%, with relatively low urbanization rate, 0.06% with medium level of urbanization rate,and 0.38% with high level of urbanization rate.展开更多
基金Supported by the National Natural Science Foundation of China(Grant No.12371516)the Natural Science Foundation of Liaoning Province(Grant No.2022-MS-152)the Fundamental Research Funds for the Central Universities(Grant No.DUT22LAB305)。
文摘This paper mainly studies the influence maximization problem of threshold models in hypergraphs,which aims to identify the most influential nodes in hypergraphs.Firstly,we introduce a novel information diffusion rule in hypergraphs based on Threshold Models and conduct the stability analysis.Then we extend the CI-TM algorithm,originally designed for complex networks,to hypergraphs,denoted as the H-CI-TM algorithm.Secondly,we use an iterative approach to get the globally optimal solutions.The analysis reveals that our algorithm ultimately identifies the most influential set of nodes.Based on the numerical simulations,HCI-TM algorithm outperforms several competing algorithms in both synthetic and real-world hypergraphs.Essentially,when provided with the same number of initial seeds,our algorithm can achieve a larger activation size.Our method not only accurately assesses the influence of individual nodes but also identifies a set of nodes with greater impact.Furthermore,our results demonstrate good scalability when handling intricate relationships and large-scale hypergraphs.The outcomes of our research provide substantial support for the applications of the threshold models across diverse fields,including social network analysis and marketing strategies.
文摘The authors are to be congratulated for an innovative paper in terms of both modelling methodology and subject matter significance. The analysis of short time series is known to be
文摘This is a very attractive article. It combines fascinating new methodology with a most interesting dataset, and a highly motivating presentation. However, despite the many
文摘-In this paper, monthly mean SST data in a large area are used. After the spacial average of the data is carried out and the secular monthly means are substracted, a time series (Jan. 1951-Dec. 1985) of SST anomalies of the cold tongue water area in the eastern tropical Pacific Ocean is obtained. On the basis of the time series, an autoregression model, a self-exciting threshold autoregression model and an open loop autoregression model are developed respectively. The interannual variations are simulated by means of those models. The simulation results show that all the three models have made very good hindcasting for the nine El Nino events since 1951. In order to test the reliability of the open loop threshold model, extrapolated forecast was made for the period of Jan. 1986-Feb. 1987. It can be seen from the forecasting that the model could forecast well the beginning and strengthening stages of the recent El Nino event (1986-1987). Correlation coefficients of the estimations to observations are respectively 0. 84, 0. 88 and 0. 89. It is obvious that all the models work well and the open loop threshold one is the best. So the open loop threshold autoregression model is a useful tool for monitoring the SSTinterannual variation of the cold tongue water area in the Eastern Equatorial Pacific Ocean and for estimating the El Nino strength.
基金Supported by the Natural Science Foundation of Fujian Province(2022J011177,2024J01903)the Key Project of Fujian Provincial Education Department(JZ230054)。
文摘In clinical research,subgroup analysis can help identify patient groups that respond better or worse to specific treatments,improve therapeutic effect and safety,and is of great significance in precision medicine.This article considers subgroup analysis methods for longitudinal data containing multiple covariates and biomarkers.We divide subgroups based on whether a linear combination of these biomarkers exceeds a predetermined threshold,and assess the heterogeneity of treatment effects across subgroups using the interaction between subgroups and exposure variables.Quantile regression is used to better characterize the global distribution of the response variable and sparsity penalties are imposed to achieve variable selection of covariates and biomarkers.The effectiveness of our proposed methodology for both variable selection and parameter estimation is verified through random simulations.Finally,we demonstrate the application of this method by analyzing data from the PA.3 trial,further illustrating the practicality of the method proposed in this paper.
基金financially supported by National 863 Program (Grants No.2006AA 09A 102-09)National Science and Technology of Major Projects ( Grants No.2008ZX0 5025-001-001)
文摘Irregular seismic data causes problems with multi-trace processing algorithms and degrades processing quality. We introduce the Projection onto Convex Sets （POCS） based image restoration method into the seismic data reconstruction field to interpolate irregularly missing traces. For entire dead traces, we transfer the POCS iteration reconstruction process from the time to frequency domain to save computational cost because forward and reverse Fourier time transforms are not needed. In each iteration, the selection threshold parameter is important for reconstruction efficiency. In this paper, we designed two types of threshold models to reconstruct irregularly missing seismic data. The experimental results show that an exponential threshold can greatly reduce iterations and improve reconstruction efficiency compared to a linear threshold for the same reconstruction result. We also analyze the anti- noise and anti-alias ability of the POCS reconstruction method. Finally, theoretical model tests and real data examples indicate that the proposed method is efficient and applicable.
基金supported by the Research Center for Aging Career and Industrial Development,Sichuan Key Research Base of Social Sciences[Grant No.XJLL2022009].
文摘Global population aging trends are intensifying,presenting multifaceted economic and social challenges for countries worldwide.As the world’s largest developing country,China has entered a phase of extreme demographic aging,posing significant questions about its impact on the ongoing upgrading of industrial structures.How does this demographic shift influence the upgrading of industrial structures,and does technological innovation mitigate or exacerbate this impact?The empirical results indicate that population aging impedes upgrading the industrial structure,while technological innovation positively affects the relationship between the two.Moreover,using technological innovation as a threshold variable,the impact of population aging on industrial structure upgrading evolves in a“gradient”manner from“impediment”to“insignificant”to“promotion”as the technological innovation levels increase.These findings offer practical guidance for tailoring industrial policies to different stages of technological advancement.
文摘To avoid missing track caused by the target maneuvers in automatic target tracking system, a new maneuvering target tracking technique called threshold interacting multiple model （TIMM） is proposed. This algorithm is based on the interacting multiple model （IMM） method and applies a threshold controller to improve tracking accuracy. It is also applicable to other advanced algorithms of IMM. In this research, we also compare the position and velocity root mean square （RMS） errors of TIMM and IMM algorithms with two different examples. Simulation results show that the TIMM algorithm is superior to the traditional IMM alzorithm in estimation accuracy.
文摘The subset threshold auto regressive (SSTAR) model, which is capable of reproducing the limit cycle behavior of nonlinear time series, is introduced. The algorithm for fitting the sampled data with SSTAR model is proposed and applied to model and forecast power load. Numerical example verifies that desirable accuracy of short term load forecasting can be achieved by using the SSTAR model.
文摘Longevity and stay ability are parameters in any breeding programme. </span><span style="font-family:Verdana;">The </span><span style="font-family:Verdana;">Overstaying of any animal </span><span style="font-family:Verdana;">o</span><span style="font-family:Verdana;">n a farm has got negative effects </span><span style="font-family:Verdana;">on</span><span style="font-family:Verdana;"> the farmer. Short stay also means early exit of good animal</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> that could have been used for a longer time and more productive. The intention of this review paper is to emphasize the importance of models that an upcoming breeding program can use without affecting the quality of the herd. In this paper</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> longevity is taken purely on </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">performance measure. The functional and type traits of longevity should be studied further before all models are put into play. But the case of closed breeding programmes, performance traits are easily measurable because many animals will exit the herd as they have been sold to farmers hence many functional straits will be expressed outside the herd. Genetic evaluation of the Kenyan Sahiwal should account for inbreeding. This study has also </span><span style="font-family:Verdana;">provided genetic and phenotypic parameters to enable </span></span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">inclusion of longevity in the breeding objective for the Sahiwal cattle improvement pro</span><span style="font-family:Verdana;">gramme.
文摘A grain-based distinct element model featuring three-dimensional （3D） Voronoi tessellations （randompoly-crystals） is proposed for simulation of crack damage development in brittle rocks. The grainboundaries in poly-crystal structure produced by Voronoi tessellations can represent flaws in intact rockand allow for numerical replication of crack damage progression through initiation and propagation ofmicro-fractures along grain boundaries. The Voronoi modelling scheme has been used widely in the pastfor brittle fracture simulation of rock materials. However the difficulty of generating 3D Voronoi modelshas limited its application to two-dimensional （2D） codes. The proposed approach is implemented inNeper, an open-source engine for generation of 3D Voronoi grains, to generate block geometry files thatcan be read directly into 3DEC. A series of Unconfined Compressive Strength （UCS） tests are simulated in3DEC to verify the proposed methodology for 3D simulation of brittle fractures and to investigate therelationship between each micro-parameter and the model＇s macro-response. The possibility of numericalreplication of the classical U-shape strength curve for anisotropic rocks is also investigated innumerical UCS tests by using complex-shaped （elongated） grains that are cemented to one another alongtheir adjoining sides. A micro-parameter calibration procedure is established for 3D Voronoi models foraccurate replication of the mechanical behaviour of isotropic and anisotropic （containing a fabric） rocks. 2014 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.
基金Supported by the Natural Science Foundation of Hebei Province under Grant No C2013202192
文摘Species evolution is essentially a random process of interaction between biological populations and their environ- ments. As a result, some physical parameters in evolution models are subject to statistical fluctuations. In this work, two important parameters in the Eigen model, the fitness and mutation rate, are treated as Gaassian dis- tributed random variables simultaneously to examine the property of the error threshold. Numerical simulation results show that the error threshold in the fully random model appears as a crossover region instead of a phase transition point, and ＆s the fluctuation strength increases the crossover region becomes smoother and smoother. Furthermore, it is shown that the randomization of the mutation rate plays a dominant role in changing the error threshold in the fully random model, which is consistent with the existing experimental data. The implication of the threshold change due to the randomization for antiviral strategies is discussed.
基金funded by the National Social Science Foundation of China(Grant No.20CMZ033)。
文摘Questions persist on the relationship between tourism dependence and economic growth in ethnic tourism areas.This study addresses such gaps by constructing a threshold regression model based on socio-economic data from 2006 to 2019 for nine sites in Enshi Prefecture of central China.Arc GIS and other open-source data were also used to visualize changing tourism resources in the region.Findings suggest that tourism dependence(the ratio of tourism-based GDP to overall GDP)significantly promotes economic growth in ethnic minority areas.However,the positive influence of tourism dependence on economic growth appears dynamic and non-linear–rising at first before falling when tourism dependence exceeded a threshold of 34%,with effects varying by site and year.Methods and findings make crucial theoretical contributions to understanding tourism dependence and poverty alleviation linkages.This paper also highlights the importance of political support and balanced investment in diverse industries to minimize decreasing returns beyond tourism dependence thresholds in destinations worldwide.
基金ACKNOWLEDGEMENTS Project supported by the National Social Science Foundation of China （Grant No. 11BGL041）, Ministry of Education Humanities and Social Sciences General Project （12YJA630166）.
文摘The innovations actually diffuse among social network nowadays.Individual heterogeneity,interactions between individuals and network topology influence a lot.We established a "double threshold" modified model and took the number of neighbors,neighbors' adoption and the cost-benefit parameters as crucial influencing factors.The diffusion of DaLingTong(CDMA450)products in MeiShan city of SiChuan province during 2004 to 2007 has been used to verity the model on Matlab.The validation results fit the actual diffusion pattern of DaLingTong(CDMA450) products very well.The results indicate that there exists a "tipping point(threshold)" in the process of innovation diffusion.If the initial adoption quantity is larger than the tipping point,then the product will spread to a large portion of people,otherwise is will collapse to zero.The model can effectively predict the diffusion of new products,and can influence the diffusion process by changing the value of the parameters.
文摘Large-strain deformations introduce several confounding factors that affect the application of the Mechanical Threshold Stress model. These include the decrease with the increasing stress of the normalized activation energy characterizing deformation kinetics, the tendency toward Stage IV hardening at high strains, and the influence of crystallographic texture. Minor additions to the Mechanical Threshold Stress model are introduced to account for variations of the activation energy and the addition of Stage IV hardening. Crystallographic texture cannot be modeled using an isotropic formulation, but some common trends when analyzing predominantly shear deformation followed by uniaxial deformation are described. Comparisons of model predictions with measurements in copper processed using Equal Channel Angular Pressing are described.
基金supported by the National Social Science Foundation of China(Grant No.22BTJ048)the National Natural Science Foundation of China(Grant No.72403001)+4 种基金the Social Sciences Planning Youth Project of Anhui Province(Grant No.AHSKQ2022D138)the Natural Science Foundation of Anhui Province(Grant No.2408085QG228)the Anhui Province Excellent Young Talents Fund Program of Higher Education Institutions(Grant No.2023AH030015)the Innovation Development Research Project of Anhui Province(Grant No.2023CX507)the Scientific Research Project of Anhui University of Finance and Economics(Grant No.ACYC2022505).
文摘In the backdrop of“dual-carbon”strategic objectives,understanding the influence of the digital economy(DE)on carbon emissions(CEs)is imperative.However,there is limited research on the DE’s negative impact on CEs and the nonlinear relationship between the DE and CE.To address this gap,we collected data from 270 Chinese cities from 2011 to 2021 and used benchmark regression,mediated effects,and panel threshold models to explore the DE’s impact on CEs.The results showed that DE had a nonlinear,inverted U-shaped effect on CEs,with CEs initially increasing and then being suppressed.This conclusion remained consistent even after a series of robustness tests.Overall,the rate of urbanization and breadth of digital financial coverage mediate the relationship between the DE and CEs.Additionally,the combined effects of economic development,environmental regulation,fiscal decentralization,and population size contribute to the DE’s nonlinear impact on CEs.The impact of the DE on CEs varies among nonresource-based,resource-based,and resource-depleted cities and between urban and nonurban agglomerations.This paper’s findings support the development of the DE and the formulation of CE reduction policies.
基金supported by the Key Project of National Philosophy and Social Science Foundation of China(Grant No.24AGL007).
文摘Economic growth and environmental pollution have become the bases of geopolitical competition due to the multiple constraints of growth in energy consumption and environmental protection in recent decades.Whether the coordinated development of inward foreign direct investment(IFDI)and outward foreign direct investment(OFDI)promote economic growth while reducing environmental pollution and realizing high-quality development affects the overall socialist modernization under China’s“Dual Circulation”policy.Using China’s provincial panel data from 2005 to 2020,this paper first measured green total factor productivity(GTFP)and the coordinated development index(CDIFDI)of IFDI and OFDI via the slacks-based measureglobal Malmquist–Luenberger(SBM-GML)model and the capacity coupling model.A panel threshold model with interactive effects(PTIFEs)was then applied to explore the nonlinear impact of the CDIFDI on China’s GTFP.Finally,a regional heterogeneity analysis was conducted for China’s eastern,central and western regions of China.Results show that(1)GTFP in China kept rising with small fluctuations during the sample period,with the increasing range of GTFP decreasing from east to west.(2)CDIFDI had a significant“U”-shaped threshold effect on GTFP,and the main threshold variables were the industrial structure and the level of economic development.(3)CDIFDI played a positive role in promoting GTFP growth in the eastern region,while the effects of CDIFDI on GTFP in the central and western regions were not significant.Policy-makers and enterprises should comprehensively consider promoting regional industrial upgrading and economic growth to achieve a greater positive impact of CDIFDI on GTFP.Scientifically measuring GTFP and exploring the nonlinear impact of the CDIFDI on GTFP and regional heterogeneity provide helpful references for policy-makers to coordinate the high-quality development of regional economies.
基金supported by the National Natural Science Foundation of China(Nos.U1262207 and 41204101)the National Science and Technology Major Project of China(No.2011ZX05019-006)
文摘The efficiency, precision, and denoising capabilities of reconstruction algorithms are critical to seismic data processing. Based on the Fourier-domain projection onto convex sets （POCS） algorithm, we propose an inversely proportional threshold model that defines the optimum threshold, in which the descent rate is larger than in the exponential threshold in the large-coefficient section and slower than in the exponential threshold in the small-coefficient section. Thus, the computation efficiency of the POCS seismic reconstruction greatly improves without affecting the reconstructed precision of weak reflections. To improve the flexibility of the inversely proportional threshold, we obtain the optimal threshold by using an adjustable dependent variable in the denominator of the inversely proportional threshold model. For random noise attenuation by completing the missing traces in seismic data reconstruction, we present a weighted reinsertion strategy based on the data-driven model that can be obtained by using the percentage of the data-driven threshold in each iteration in the threshold section. We apply the proposed POCS reconstruction method to 3D synthetic and field data. The results suggest that the inversely proportional threshold model improves the computational efficiency and precision compared with the traditional threshold models; furthermore, the proposed reinserting weight strategy increases the SNR of the reconstructed data.
文摘This paper uses inter-provincial panel data from 2011 to 2017,a linear regression model,and a threshold model to conduct empirical analyses of the impact of the digital economy on China's overall economic growth and the three main sectors of industry.The paper then investigates the impact and effects the digital economy has had on the economic growth of the three main sectors of industry in China's eastern,central,and western regions.Finally,the paper investigates the most significant differences among the various regions and the threshold effects of urbanization levels on the relationship between the digital economy and economic growth.The findings indicate a significantly positive correlation between the digital economy and regional economic growth.Moreover,geographical factors notably influence this correlation.The digital economy exerts a positive effect on all sectors of industry.It may not substantially impact industrial development in regions with highly developed infrastructure.Regarding the other regions,the digital economy exhibits varying degrees of impact due to the differences in the specific indicators.The conclusion drawn by the threshold model is that the magnitude of the threshold effect correlates with geographic factors.No threshold effect was observed in the eastern region,while the threshold effect occurred in the central region when the urbanization levels for the provinces were below 0.6645.Similarly,the threshold effect was noted in the western region when the urbanization level was below 0.3931.Considering all of this,the study also offers policy recommendations that will help balance the regional development of digital economies,accelerate the digital transformation of traditional industries,enhance digital infrastructure construction,refine the formulation and implementation of data policy,and establish relevant incentive mechanisms.
基金Supported by Natural Science Foundation of China(71850014,71532013,71573244,71974180)。
文摘Scholars have a variety of theoretical explanations for housing price growth. However, few scholars have studied the internal influence mechanism among urbanization, land finance, and housing price. Based on the data of 182 prefecture-level cities from 2009 to 2016, this paper studies the influence of land finance on housing price under different urbanization rate levels. The study finds that with the increase of urbanization rate, the effect of land finance on housing price presents a "U" shape.Specifically, an increase in land finance by 1% results in a corresponding increase in average housing price by 0.18%, with relatively low urbanization rate, 0.06% with medium level of urbanization rate,and 0.38% with high level of urbanization rate.
