Cellular Automata(CA) is widely used for the simulation of land use changes. This study applied a vector-based CA model to simulate land use change in order to minimize or eliminate the scale sensitivity in traditiona...Cellular Automata(CA) is widely used for the simulation of land use changes. This study applied a vector-based CA model to simulate land use change in order to minimize or eliminate the scale sensitivity in traditional raster-based CA model. The cells of vector-based CA model are presented according to the shapes and attributes of geographic entities, and the transition rules of vector-based CA model are improved by taking spatial variables of the study area into consideration. The vector-based CA model is applied to simulate land use changes in downtown of Qidong City, Jiangsu Province, China and its validation is confirmed by the methods of visual assessment and spatial accuracy. The simulation result of vector-based CA model reveals that nearly 75% of newly increased urban cells are located in the northwest and southwest parts of the study area from 2002 to 2007, which is in consistent with real land use map. In addition, the simulation results of the vector-based and raster-based CA models are compared to real land use data and their spatial accuracies are found to be 84.0% and 81.9%, respectively. In conclusion, results from this study indicate that the vector-based CA model is a practical and applicable method for the simulation of urbanization processes.展开更多
The accessibility provided by the transportation system plays an essential role in driving urban growth and urban functional land use changes.Conventional studies on land use simulation usually simplified the accessib...The accessibility provided by the transportation system plays an essential role in driving urban growth and urban functional land use changes.Conventional studies on land use simulation usually simplified the accessibility as proximities and adopted the grid-based simulation strategy,leading to the insufficiencies of characterizing spatial geometry of land parcels and simulating subtle land use changes among urban functional types.To overcome these limita-tions,an Accessibility-interacted Vector-based Cellular Automata(A-VCA)model was proposed for the better simulation of realistic land use change among different urban functional types.The accessibility at both local and zonal scales derived from actual travel time data was considered as a key driver of fine-scale urban land use changes and was integrated into the vector-based CA simulation process.The proposed A-VCA model was tested through the simulation of urban land use changes in the City of Toronto,Canada,during 2012-2016.A vector-based CA without considering the driving factor of accessibility(VCA)and a popular grid-based CA model(Future Land Use Simulation,FLUS)were also implemented for compar-isons.The simulation results reveal that the proposed A-VCA model is capable of simulating fine-scale urban land use changes with satisfactory accuracy and good morphological feature(kappa=0.907,figure of merit=0.283,and cumulative producer’s accuracy=72.83%±1.535%).The comparison also shows significant outperformance of the A-VCA model against the VCA and FLUS models,suggesting the effectiveness of the accessibility-interactive mechanism and vector-based simulation strategy.The proposed model provides new tools for a better simula-tion of fine-scale land use changes and can be used in assisting the formulation of urban and transportation planning.展开更多
为满足复杂干扰场景和阵列误差因素影响下雷达微弱目标信号精确测向需求,提出一种基于均匀线阵构建虚拟波束,替代阵列接收信号进行四阶累积量(fourth-order cumulant,FOC)波达方向(direction of arrival,DOA)估计的算法。该算法包括两...为满足复杂干扰场景和阵列误差因素影响下雷达微弱目标信号精确测向需求,提出一种基于均匀线阵构建虚拟波束,替代阵列接收信号进行四阶累积量(fourth-order cumulant,FOC)波达方向(direction of arrival,DOA)估计的算法。该算法包括两个关键步骤:一是利用阵列接收信号特征分解的方法,对信号主信息分量进行提取,并以构建的虚拟波束为输入,计算FOC矩阵;二是针对主分量虚拟波束波瓣外的起伏,利用高斯窗修正波束方向图的方法,进一步提升空间谱函数的估计精度。仿真结果表明,该方法在存在阵列误差的非理想因素下,对复杂电磁干扰场景下的目标信号DOA估计精度较现有FOC方法提高150%以上,尤其对于场内同时存在多个非等功率源信号时,所提方法对低信噪比目标DOA估计精度提升效果优势明显,对复杂干扰环境下DOA估计精度更高、适应性更强。展开更多
This paper firstly introduces the structure and working principle of DSP-based parallel system, parallel accelerating board and SHARC DSP chip. Then it pays attention to investigating the system’s programming charact...This paper firstly introduces the structure and working principle of DSP-based parallel system, parallel accelerating board and SHARC DSP chip. Then it pays attention to investigating the system’s programming characteristics, especially the mode of communication, discussing how to design parallel algorithms and presenting a domain-decomposition-based complete multi-grid parallel algorithm with virtual boundary forecast (VBF) to solve a lot of large-scale and complicated heat problems. In the end, Mandelbrot Set and a non-linear heat transfer equation of ceramic/metal composite material are taken as examples to illustrate the implementation of the proposed algorithm. The results showed that the solutions are highly efficient and have linear speedup.展开更多
Hepatitis C virus(HCV)is responsible for no less than 71 million people chronically infected and is one of the most frequent indications for liver transplanta-tion worldwide.Despite direct-acting antiviral therapies f...Hepatitis C virus(HCV)is responsible for no less than 71 million people chronically infected and is one of the most frequent indications for liver transplanta-tion worldwide.Despite direct-acting antiviral therapies fuel optimism in controlling HCV infections,there are several obstacles regarding treatment accessibility and reinfection continues to remain a possibility.Indeed,the majority of new HCV infections in developed countries occur in people who inject drugs and are more plausible to get reinfected.To achieve global epidemic control of this virus the development of an effective prophylactic or therapeutic vaccine becomes a must.The coronavirus disease 19(COVID-19)pandemic led to auspicious vaccine development against severe acute respiratory syndrome coronavirus-2(SARSCoV-2)virus,which has renewed interest on fighting HCV epidemic with vaccination.The aim of this review is to highlight the current situation of HCV vaccine candidates designed to prevent and/or to reduce HCV infectious cases and their complications.We will emphasize on some of the crossroads encountered during vaccine development against this insidious virus,together with some key aspects of HCV immunology which have,so far,ham-pered the progress in this area.The main focus will be on nucleic acid-based as well as recombinant viral vector-based vaccine candidates as the most novel vaccine approaches,some of which have been recently and successfully employed for SARS-CoV-2 vaccines.Finally,some ideas will be presented on which methods to explore for the design of live-attenuated vaccines against HCV.展开更多
The potential of muon colliders opens up new possibilities for the exploration of new physics beyond the Standard Model.It is worthwhile to investigate whether muon colliders are suitable for studying gluonic quartic ...The potential of muon colliders opens up new possibilities for the exploration of new physics beyond the Standard Model.It is worthwhile to investigate whether muon colliders are suitable for studying gluonic quartic gauge couplings(gQGCs),which can be contributed by dimension-8 operators in the framework of the Standard Model effective field theory,and are intensively studied recently.In this paper,we study the sensitivity of the processμ^(+)μ^(-)→jjν■to gQGCs.Our results indicate that the muon colliders with c.m.energies larger than 4 TeV can be more sensitive to gQGCs than the Large Hadron Collider.展开更多
Experiments were conducted to evaluate the performance of vertical blowing fans(VBF)for frost protection in a vineyard on a steep slope near Napa Valley in Northern California,USA,and a tea plantation located on undul...Experiments were conducted to evaluate the performance of vertical blowing fans(VBF)for frost protection in a vineyard on a steep slope near Napa Valley in Northern California,USA,and a tea plantation located on undulating terrain in Zhenjiang,China.Minimum temperature comparisons from within the grape vineyard on nights with and without VBF operation with control station minimum temperatures exhibited no temperature benefit.Profile measurements from the test in China indicated that there was an increase in temperature when the VBF was first started,but that benefit was lost over time.No clear benefit from using the VBF was observed.Observation of frost deposition and thermal imagery also showed no benefit except for within about 5 m of the VBF.Based on this work,the effectiveness of the VBF for frost protection was not validated.展开更多
Automated essay scoring(AES)systems have gained significant importance in educational settings,offering a scalable,efficient,and objective method for evaluating student essays.However,developing AES systems for Arabic...Automated essay scoring(AES)systems have gained significant importance in educational settings,offering a scalable,efficient,and objective method for evaluating student essays.However,developing AES systems for Arabic poses distinct challenges due to the language’s complex morphology,diglossia,and the scarcity of annotated datasets.This paper presents a hybrid approach to Arabic AES by combining text-based,vector-based,and embeddingbased similarity measures to improve essay scoring accuracy while minimizing the training data required.Using a large Arabic essay dataset categorized into thematic groups,the study conducted four experiments to evaluate the impact of feature selection,data size,and model performance.Experiment 1 established a baseline using a non-machine learning approach,selecting top-N correlated features to predict essay scores.The subsequent experiments employed 5-fold cross-validation.Experiment 2 showed that combining embedding-based,text-based,and vector-based features in a Random Forest(RF)model achieved an R2 of 88.92%and an accuracy of 83.3%within a 0.5-point tolerance.Experiment 3 further refined the feature selection process,demonstrating that 19 correlated features yielded optimal results,improving R2 to 88.95%.In Experiment 4,an optimal data efficiency training approach was introduced,where training data portions increased from 5%to 50%.The study found that using just 10%of the data achieved near-peak performance,with an R2 of 85.49%,emphasizing an effective trade-off between performance and computational costs.These findings highlight the potential of the hybrid approach for developing scalable Arabic AES systems,especially in low-resource environments,addressing linguistic challenges while ensuring efficient data usage.展开更多
基金Under the auspices of National Natural Science Foundation of China(No.41101349)Surveying and Mapping Scientific Research Projects of Jiangsu Province(No.JSCHKY201304)+1 种基金Program of Natural Science Research of Jiangsu Higher Education Institutions of China(No.13KJB420003)Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Cellular Automata(CA) is widely used for the simulation of land use changes. This study applied a vector-based CA model to simulate land use change in order to minimize or eliminate the scale sensitivity in traditional raster-based CA model. The cells of vector-based CA model are presented according to the shapes and attributes of geographic entities, and the transition rules of vector-based CA model are improved by taking spatial variables of the study area into consideration. The vector-based CA model is applied to simulate land use changes in downtown of Qidong City, Jiangsu Province, China and its validation is confirmed by the methods of visual assessment and spatial accuracy. The simulation result of vector-based CA model reveals that nearly 75% of newly increased urban cells are located in the northwest and southwest parts of the study area from 2002 to 2007, which is in consistent with real land use map. In addition, the simulation results of the vector-based and raster-based CA models are compared to real land use data and their spatial accuracies are found to be 84.0% and 81.9%, respectively. In conclusion, results from this study indicate that the vector-based CA model is a practical and applicable method for the simulation of urbanization processes.
基金the National Key R&D Program of China[Grant Number 2019YFA0607203]the National Natural Science Foundation of China[Grant Number 42001326 and 42171410]the Natural Science Foundation of Guangdong Province of China[Grant Number 2021A1515011192].
文摘The accessibility provided by the transportation system plays an essential role in driving urban growth and urban functional land use changes.Conventional studies on land use simulation usually simplified the accessibility as proximities and adopted the grid-based simulation strategy,leading to the insufficiencies of characterizing spatial geometry of land parcels and simulating subtle land use changes among urban functional types.To overcome these limita-tions,an Accessibility-interacted Vector-based Cellular Automata(A-VCA)model was proposed for the better simulation of realistic land use change among different urban functional types.The accessibility at both local and zonal scales derived from actual travel time data was considered as a key driver of fine-scale urban land use changes and was integrated into the vector-based CA simulation process.The proposed A-VCA model was tested through the simulation of urban land use changes in the City of Toronto,Canada,during 2012-2016.A vector-based CA without considering the driving factor of accessibility(VCA)and a popular grid-based CA model(Future Land Use Simulation,FLUS)were also implemented for compar-isons.The simulation results reveal that the proposed A-VCA model is capable of simulating fine-scale urban land use changes with satisfactory accuracy and good morphological feature(kappa=0.907,figure of merit=0.283,and cumulative producer’s accuracy=72.83%±1.535%).The comparison also shows significant outperformance of the A-VCA model against the VCA and FLUS models,suggesting the effectiveness of the accessibility-interactive mechanism and vector-based simulation strategy.The proposed model provides new tools for a better simula-tion of fine-scale land use changes and can be used in assisting the formulation of urban and transportation planning.
文摘为满足复杂干扰场景和阵列误差因素影响下雷达微弱目标信号精确测向需求,提出一种基于均匀线阵构建虚拟波束,替代阵列接收信号进行四阶累积量(fourth-order cumulant,FOC)波达方向(direction of arrival,DOA)估计的算法。该算法包括两个关键步骤:一是利用阵列接收信号特征分解的方法,对信号主信息分量进行提取,并以构建的虚拟波束为输入,计算FOC矩阵;二是针对主分量虚拟波束波瓣外的起伏,利用高斯窗修正波束方向图的方法,进一步提升空间谱函数的估计精度。仿真结果表明,该方法在存在阵列误差的非理想因素下,对复杂电磁干扰场景下的目标信号DOA估计精度较现有FOC方法提高150%以上,尤其对于场内同时存在多个非等功率源信号时,所提方法对低信噪比目标DOA估计精度提升效果优势明显,对复杂干扰环境下DOA估计精度更高、适应性更强。
基金Project (No. 60173046) supported by the National Natural ScienceFoundation of China
文摘This paper firstly introduces the structure and working principle of DSP-based parallel system, parallel accelerating board and SHARC DSP chip. Then it pays attention to investigating the system’s programming characteristics, especially the mode of communication, discussing how to design parallel algorithms and presenting a domain-decomposition-based complete multi-grid parallel algorithm with virtual boundary forecast (VBF) to solve a lot of large-scale and complicated heat problems. In the end, Mandelbrot Set and a non-linear heat transfer equation of ceramic/metal composite material are taken as examples to illustrate the implementation of the proposed algorithm. The results showed that the solutions are highly efficient and have linear speedup.
基金Supported by Programa de Desarrollo de las Ciencias Basicas(PEDECIBA)Comision Academica de Posgrados,Universidad de la Republica Uruguay(UdelaR)Comision Sectorial de Investigacion Cientifica(CSIC,I+D Project ID288).
文摘Hepatitis C virus(HCV)is responsible for no less than 71 million people chronically infected and is one of the most frequent indications for liver transplanta-tion worldwide.Despite direct-acting antiviral therapies fuel optimism in controlling HCV infections,there are several obstacles regarding treatment accessibility and reinfection continues to remain a possibility.Indeed,the majority of new HCV infections in developed countries occur in people who inject drugs and are more plausible to get reinfected.To achieve global epidemic control of this virus the development of an effective prophylactic or therapeutic vaccine becomes a must.The coronavirus disease 19(COVID-19)pandemic led to auspicious vaccine development against severe acute respiratory syndrome coronavirus-2(SARSCoV-2)virus,which has renewed interest on fighting HCV epidemic with vaccination.The aim of this review is to highlight the current situation of HCV vaccine candidates designed to prevent and/or to reduce HCV infectious cases and their complications.We will emphasize on some of the crossroads encountered during vaccine development against this insidious virus,together with some key aspects of HCV immunology which have,so far,ham-pered the progress in this area.The main focus will be on nucleic acid-based as well as recombinant viral vector-based vaccine candidates as the most novel vaccine approaches,some of which have been recently and successfully employed for SARS-CoV-2 vaccines.Finally,some ideas will be presented on which methods to explore for the design of live-attenuated vaccines against HCV.
基金supported in part by the National Natural Science Foundation of China under Grants Nos.11905093 and 12147214the Natural Science Foundation of the Liaoning Scientific Committee No.LJKZ0978.
文摘The potential of muon colliders opens up new possibilities for the exploration of new physics beyond the Standard Model.It is worthwhile to investigate whether muon colliders are suitable for studying gluonic quartic gauge couplings(gQGCs),which can be contributed by dimension-8 operators in the framework of the Standard Model effective field theory,and are intensively studied recently.In this paper,we study the sensitivity of the processμ^(+)μ^(-)→jjν■to gQGCs.Our results indicate that the muon colliders with c.m.energies larger than 4 TeV can be more sensitive to gQGCs than the Large Hadron Collider.
基金This work was funded by National High Technology Research and Development Program of China(2012AA10A508)Special Fund of Non-profit Scientific Research for Agriculture(201303012)Priority Academic Program Development of Jiangsu Higher Education Institutions(2014-37).
文摘Experiments were conducted to evaluate the performance of vertical blowing fans(VBF)for frost protection in a vineyard on a steep slope near Napa Valley in Northern California,USA,and a tea plantation located on undulating terrain in Zhenjiang,China.Minimum temperature comparisons from within the grape vineyard on nights with and without VBF operation with control station minimum temperatures exhibited no temperature benefit.Profile measurements from the test in China indicated that there was an increase in temperature when the VBF was first started,but that benefit was lost over time.No clear benefit from using the VBF was observed.Observation of frost deposition and thermal imagery also showed no benefit except for within about 5 m of the VBF.Based on this work,the effectiveness of the VBF for frost protection was not validated.
基金funded by Deanship of Graduate studies and Scientific Research at Jouf University under grant No.(DGSSR-2024-02-01264).
文摘Automated essay scoring(AES)systems have gained significant importance in educational settings,offering a scalable,efficient,and objective method for evaluating student essays.However,developing AES systems for Arabic poses distinct challenges due to the language’s complex morphology,diglossia,and the scarcity of annotated datasets.This paper presents a hybrid approach to Arabic AES by combining text-based,vector-based,and embeddingbased similarity measures to improve essay scoring accuracy while minimizing the training data required.Using a large Arabic essay dataset categorized into thematic groups,the study conducted four experiments to evaluate the impact of feature selection,data size,and model performance.Experiment 1 established a baseline using a non-machine learning approach,selecting top-N correlated features to predict essay scores.The subsequent experiments employed 5-fold cross-validation.Experiment 2 showed that combining embedding-based,text-based,and vector-based features in a Random Forest(RF)model achieved an R2 of 88.92%and an accuracy of 83.3%within a 0.5-point tolerance.Experiment 3 further refined the feature selection process,demonstrating that 19 correlated features yielded optimal results,improving R2 to 88.95%.In Experiment 4,an optimal data efficiency training approach was introduced,where training data portions increased from 5%to 50%.The study found that using just 10%of the data achieved near-peak performance,with an R2 of 85.49%,emphasizing an effective trade-off between performance and computational costs.These findings highlight the potential of the hybrid approach for developing scalable Arabic AES systems,especially in low-resource environments,addressing linguistic challenges while ensuring efficient data usage.
