In computer vision,convolutional neural networks have a wide range of uses.Images representmost of today’s data,so it’s important to know how to handle these large amounts of data efficiently.Convolutional neural ne...In computer vision,convolutional neural networks have a wide range of uses.Images representmost of today’s data,so it’s important to know how to handle these large amounts of data efficiently.Convolutional neural networks have been shown to solve image processing problems effectively.However,when designing the network structure for a particular problem,you need to adjust the hyperparameters for higher accuracy.This technique is time consuming and requires a lot of work and domain knowledge.Designing a convolutional neural network architecture is a classic NP-hard optimization challenge.On the other hand,different datasets require different combinations of models or hyperparameters,which can be time consuming and inconvenient.Various approaches have been proposed to overcome this problem,such as grid search limited to low-dimensional space and queuing by random selection.To address this issue,we propose an evolutionary algorithm-based approach that dynamically enhances the structure of Convolution Neural Networks(CNNs)using optimized hyperparameters.This study proposes a method using Non-dominated sorted genetic algorithms(NSGA)to improve the hyperparameters of the CNN model.In addition,different types and parameter ranges of existing genetic algorithms are used.Acomparative study was conducted with various state-of-the-art methodologies and algorithms.Experiments have shown that our proposed approach is superior to previous methods in terms of classification accuracy,and the results are published in modern computing literature.展开更多
How to quickly and accurately detect new topics from massive data online becomes a main problem of public opinion monitoring in cyberspace. This paperpresents a new event detection method for the current new event det...How to quickly and accurately detect new topics from massive data online becomes a main problem of public opinion monitoring in cyberspace. This paperpresents a new event detection method for the current new event detection system, based on sorted subtopic matching algorithm and constructs the entire design framework. In this p^per, the subtopics contained in old topics （or news stories） are sorted in descending order according to their importance to the topic（or news stories）, and form a sorted subtopic sequence. In the process of subtopic matching, subtopic scoring matrix is used to determine whether a new story is reporting a new event. Experimental results show that the sorted subtopic matching model improved the accuracy and effectiveness ofthenew event detection system in cyberspace.展开更多
A new file assignment strategy of parallel I/O, which is named heuristic file sorted assignment algorithm was proposed on cluster computing system. Based on the load balancing, it assigns the files to the same disk ac...A new file assignment strategy of parallel I/O, which is named heuristic file sorted assignment algorithm was proposed on cluster computing system. Based on the load balancing, it assigns the files to the same disk according to the similar service time. Firstly, the files were sorted and stored at the set I in descending order in terms of their service time, then one disk of cluster node was selected randomly when the files were to be assigned, and at last the continuous files were taken orderly from the set I to the disk until the disk reached its load maximum. The experimental results show that the new strategy improves the performance by 20.2% when the load of the system is light and by 31.6% when the load is heavy. And the higher the data access rate, the more evident the improvement of the performance obtained by the heuristic file sorted assignment algorithm.展开更多
The purpose of this study is to analyze the household waste reduction effect of sorted collection of recyclable waste in Japan using a panel data analysis, which considers time-series and cross-section data simultaneo...The purpose of this study is to analyze the household waste reduction effect of sorted collection of recyclable waste in Japan using a panel data analysis, which considers time-series and cross-section data simultaneously. Also, the study shows the effect of the type of sorted items on the quantity of household waste disposed. We used the data attained from 103 cities recorded over three years, and applied the quantity of total waste disposed, the quantity of combustible waste, the quantity of other waste （waste excluding combustible and recyclable waste）, and the quantity of combustible plus other waste as objective variables, respectively, in the models. The result suggests that when the number of sorted items is increased marginally, the quantity of household waste decreases by about 0.5%-3.3% or 1.28-4.17 grams per capita per day. In addition, it is shown that sorting out white trays is effective in reducing the quantity of combustible waste. Sorting out paper containers and packages is also effective in reducing the quantity of other waste and combustible plus other waste.展开更多
“See it, Say it, Sorted.”就是告诉乘客,你要是看到了什么可疑的行为,就找工作人员说出来,我们协助你解决。2005年,在伦敦经历了地铁恐怖袭击之后,英国国家铁路(NationalRail)和英国交通警察局(British Transport Police)与安全专家...“See it, Say it, Sorted.”就是告诉乘客,你要是看到了什么可疑的行为,就找工作人员说出来,我们协助你解决。2005年,在伦敦经历了地铁恐怖袭击之后,英国国家铁路(NationalRail)和英国交通警察局(British Transport Police)与安全专家、传播学者以及广告创意团队进行了多次讨论与头脑风暴。团队希望创造出一条易于理解、易于记忆,同时能促使行动的标语,“Seeit.Say it. Sorted.”由此诞生。展开更多
The l1 norm is the tight convex relaxation for the l0 norm and has been successfully applied for recovering sparse signals.However,for problems with fewer samples than required for accurate l1 recovery,one needs to ap...The l1 norm is the tight convex relaxation for the l0 norm and has been successfully applied for recovering sparse signals.However,for problems with fewer samples than required for accurate l1 recovery,one needs to apply nonconvex penalties such as lp norm.As one method for solving lp minimization problems,iteratively reweighted l1 minimization updates the weight for each component based on the value of the same component at the previous iteration.It assigns large weights on small components in magnitude and small weights on large components in magnitude.The set of the weights is not fixed,and it makes the analysis of this method difficult.In this paper,we consider a weighted l1 penalty with the set of the weights fixed,and the weights are assigned based on the sort of all the components in magnitude.The smallest weight is assigned to the largest component in magnitude.This new penalty is called nonconvex sorted l1.Then we propose two methods for solving nonconvex sorted l1 minimization problems:iteratively reweighted l1 minimization and iterative sorted thresholding,and prove that both methods will converge to a local minimizer of the nonconvex sorted l1 minimization problems.We also show that both methods are generalizations of iterative support detection and iterative hard thresholding,respectively.The numerical experiments demonstrate the better performance of assigning weights by sort compared to assigning by value.展开更多
Sorted constraint representation is a very useful representation in AI which combines class hierarchies and constraint networks. For such sorted constraint representation, a problem is how to generalize the idea of de...Sorted constraint representation is a very useful representation in AI which combines class hierarchies and constraint networks. For such sorted constraint representation, a problem is how to generalize the idea of default inheritance to constraint network, where the attributes in a class or between different classes interact with each other via the network. To give a formal account for the defeasible reasoning in such representation, a general sorted constraint logic is proposed, and a minimal-model semantics for the logic is presented.展开更多
The majority(up to 90%)of riverine materials is transported from the continent to the ocean mainly in flood events.It is thus crucial to characterize the geochemistry of elements and their flux in river system in orde...The majority(up to 90%)of riverine materials is transported from the continent to the ocean mainly in flood events.It is thus crucial to characterize the geochemistry of elements and their flux in river system in order to better constrain their global biogeochemical cycling and impact on the oceanic ecosystem.However,the geochemical behavior including the distribution,migration and partitioning of typical metal elements amongst diff erent phases,during hydrodynamic flood event remains still to be well explored.Here,we investigated the geochemical behaviors of typical metal elements in dissolved phase and suspended particulate matter collected from a single flood event in the natural Chishui River,Southwest China.The results showed clearly that the geochemistry of metal elements was largely controlled by the hydrodynamic eff ect,of which the diff erent flowrates introduce a natural sorting of diff erent mineral particles transported at diff erent flood stages,depending on their shape,size and density.The maximum concentrations of alkaline and alkaline earth metals(Li,Mg,K,Rb and Sr)in SPM appeared before the flood peak,which was largely controlled by aluminosilicate minerals.However,transition metals(Cr,Mn,Fe,Ni and Cu)showed their abundance peaks lagging behind the flowrate summit,as a result of the late arrival of coarse particles or heavy minerals,evidenced by the mineralogical phase analysis.In addition,the distribution coe fficient(K_(d))between particulate and dissolved loads were lower and stable for soluble alkali/alkaline earth metals which could be aff ected by pH,while higher and fluctuant for transition metals that were largely influenced by SPM content.Overall,the present study reveals clear eff ects of hydrodynamic sorting on the geochemistry of metal elements during the flood event of the natural Chishui River,which should be taken into account when characterizing the riverine flux and their impact on marine ecosystem.展开更多
The particle size distribution plays a crucial role in the transportation and deposition of eroded sediments.Gaining insights into the related sorting mechanism can significantly enhance our understanding of such proc...The particle size distribution plays a crucial role in the transportation and deposition of eroded sediments.Gaining insights into the related sorting mechanism can significantly enhance our understanding of such processes.In this study,sand-covered slopes were examined.A controlled indoor rainfall simulation was conducted on loess slopes with a 12°incline and a rainfall intensity of 1.5 mm/min.These slopes were then covered with sand layers of varying thicknesses—0.5,1.0,and 1.5 cm—to observe their effects.The findings have revealed that as the thickness of the sand cover increases,the content of sediment particles smaller than 0.054 mm decreases.In contrast,the content of particles larger than 0.054 mm increases after the sixth minute of runoff.The eroded sediment was predominantly composed of silt.During the inter-rill erosion stage,runoff primarily transported particles larger than 0.054 mm.However,in the subsequent rill erosion and combined rill and inter-rill erosion stages,the runoff predominantly carried finer particles,smaller than 0.054 mm.Moreover,the presence of the sand layer significantly influenced the size and form of the eroded sediment particles.Initially,during the first 10 min of runoff,the eroded particles were predominantly larger than 0.054 mm.After this period,however,the particle size shifted,with the majority of particles being smaller than 0.054 mm.This study highlights the intricate relationship between sediment sorting,the thickness of sand covers,and the dynamics of sediment transport under rainfall-induced erosion.展开更多
Elucidating the mechanisms underlying community assembly remains a central question in community ecology,especially in aquatic ecosystems disrupted by human activities.Understanding the causes and consequences of comm...Elucidating the mechanisms underlying community assembly remains a central question in community ecology,especially in aquatic ecosystems disrupted by human activities.Understanding the causes and consequences of community responses to changing environment is essential for revealing the ecological effects of anthropogenic disturbances and proposing practical strategies for ecological restoration.While stochastic dispersal and species sorting are known to influence local biological communities,most studies have focused on horizontal dispersal,often neglecting the vertical exchange of organisms between planktonic and sedimentary communities when studying stochastic dispersal.We used a highly disturbed urban river in Beijing as a model system to investigate the relative roles of stochastic dispersal versus species sorting driven by local pollution,as well as two components of stochastic dispersal,vertical exchange and horizontal dispersal,in structuring local bacterial communities.Our integrated analyses of planktonic and sedimentary bacterial communities revealed that,despite different spatial patterns along the river,both types of bacterial communities were primarily shaped by stochastic dispersal processes rather than species sorting influenced by the environmental gradient.Notably,in addition to the effect of horizontal dispersal along the river,the vertical exchange between planktonic and sedimentary bacterial communities significantly contributed to the formation of local communities.These findings suggest that both vertical exchange and horizontal dispersal should be considered when assessing the role of stochastic dispersal in shaping local community structure in microbial communities.展开更多
The need to transport goods across countries and islands has resulted in a high demand for commercial vessels.Owing to such trends,shipyards must efficiently produce ships to reduce production costs.Layout and materia...The need to transport goods across countries and islands has resulted in a high demand for commercial vessels.Owing to such trends,shipyards must efficiently produce ships to reduce production costs.Layout and material flow are among the crucial aspects determining the efficiency of the production at a shipyard.This paper presents the initial design optimization of a shipyard layout using Nondominated Sorting Algorithm-Ⅱ(NSGA-Ⅱ)to find the optimal configuration of workstations in a shipyard layout.The proposed method focuses on simultaneously minimizing two material handling costs,namely work-based material handling and duration-based material handling.NSGA-Ⅱ determines the order of workstations in the shipyard layout.The semiflexible bay structure is then used in the workstation placement process from the sequence formed in NSGA-Ⅱ into a complete design.Considering that this study is a case of multiobjective optimization,the performance for both objectives at each iteration is presented in a 3D graph.Results indicate that after 500 iterations,the optimal configuration yields a work-based MHC of 163670.0 WBM-units and a duration-based MHC of 34750 DBM-units.Starting from a random solution,the efficiency of NSGA-Ⅱ demonstrates significant improvements,achieving a 50.19%reduction in work-based MHC and a 48.58%reduction in duration-based MHC.展开更多
Soft rot is a destructive disease that inflicts significant losses on agricultural production and the economy post-harvest.Biocontrol strategies based on antagonistic microorganisms have a broad application prospect t...Soft rot is a destructive disease that inflicts significant losses on agricultural production and the economy post-harvest.Biocontrol strategies based on antagonistic microorganisms have a broad application prospect to fight against plant pathogens.This study utilized fluorescence-activated droplet sorting(FADS)technology as an alternative to traditional plate culture methods to isolate microorganisms with antagonistic activity against the soft rot pathogen Erwinia carotovora Ecc15.Initially,the culture performance of the FADS platform was evaluated by analyzing bacterial diversity in droplet culture samples and agar plate culture samples,our data showed that droplet culture exhibited higher species richness and diversity than plate culture,and more than 95%of the operational taxonomic units(OTUs)in the droplet samples belonged to the rare biosphere.Additionally,we developed a green fluorescent protein(GFP)-Ecc15-based FADS screening system,which achieved an enrichment ratio of up to 148.Using this system,we successfully screened 32 antagonistic bacteria from rhizosphere soil sample of healthy konjac plants,and some may be novel microbial resources,including the genera Lelliottia,Buttiauxella and Leclercia.Notably,strain D-62 exhibited the strongest antibacterial ability against Ecc15,with an inhibition zone diameter of(20.86±1.56)mm.In vivo experiments conducted on the corms of Amorphophallus konjac demonstrated that strain D-62 could effectively reduce the infection ability of Ecc15 to the corms,indicating that strain D-62 has the potential to be developed as a biocontrol agent.Our findings suggested that the FADS screening system showed a screening efficiency approximately 3×10^(3)times higher than plate screening system,while significantly reducing costs of infrastructure,labor and consumables,it provides theoretical guidance for the screening of other plant pathogen biocontrol bacteria.展开更多
本文聚焦于基于多目标跟踪的课堂人数自动统计这一主题,提出将YOLOv8和SORT (Simple Online and Realtime Tracking)算法相结合的方法。其中,YOLOv8作为先进的单阶段目标检测算法,能迅速识别图像或视频帧中的目标并输出关键信息;SORT算...本文聚焦于基于多目标跟踪的课堂人数自动统计这一主题,提出将YOLOv8和SORT (Simple Online and Realtime Tracking)算法相结合的方法。其中,YOLOv8作为先进的单阶段目标检测算法,能迅速识别图像或视频帧中的目标并输出关键信息;SORT算法借助卡尔曼滤波预测目标位置变化。研究通过运用特定的软硬件配置开展实验,对模型进行训练与验证。该方法旨在实现课堂人数的精准自动统计,满足课堂管理和动态监控的需求,为教师及管理人员提供有力工具。其不仅在算法应用上具有创新性,而且在教育管理实践中具有重要的实用价值,有望对智慧教育领域的课堂管理产生积极深远的影响。This paper focuses on the theme of automatic counting of the number of people in the classroom based on multi-object tracking and proposes a method that combines the YOLOv8 and SORT algorithms. Among them, YOLOv8, as an advanced single-stage target detection algorithm, can quickly identify targets in an image or video frame and output key information. The SORT algorithm predicts the position change of the target with the help of Kalman filtering. The research conducts experiment by using specific software and hardware configurations to train and validate the model. This method aims to achieve accurate automatic counting of the number of people in the classroom, meet the needs of classroom management and dynamic monitoring, and provide a powerful tool for teachers and administrators. It is not only innovative in algorithm application, but also has important practical value in educational management practice, and is expected to have a positive and far-reaching impact on classroom management in the field of smart education.展开更多
煤矿井下安全生产是保障矿工生命安全和能源稳定供应的核心环节,但传统监控方法在检测实时性和准确性方面存在明显不足。针对复杂井下环境中人员入侵识别精度低的问题,研究提出一种基于改进You Only Look Once version 5(YOLOv5)和深度...煤矿井下安全生产是保障矿工生命安全和能源稳定供应的核心环节,但传统监控方法在检测实时性和准确性方面存在明显不足。针对复杂井下环境中人员入侵识别精度低的问题,研究提出一种基于改进You Only Look Once version 5(YOLOv5)和深度简单在线实时跟踪算法的电子围栏入侵检测技术。研究通过嵌入注意力机制增强模型对关键特征的感知能力,并利用扩展卡尔曼滤波与匈牙利算法提升跟踪稳定性。实验结果表明,改进后的模型的识别率最高,且随迭代次数的增加其识别率始终在90%以上。该技术在识别性能上,平均精度均值指标为92.5%,每秒帧数提升至116.7,训练时长缩短至8.5 h,漏检率显著降低。研究表明,该方法在光照不均、煤尘干扰等复杂场景下具备更高的检测精度与实时性。该技术的提出可为煤矿井下智能化安全管理提供有效技术支撑,从而提高煤矿安全生产水平,杜绝生产事故出现。展开更多
基金This research was supported by the Researchers Supporting Program(TUMAProject-2021-27)Almaarefa University,Riyadh,Saudi Arabia.
文摘In computer vision,convolutional neural networks have a wide range of uses.Images representmost of today’s data,so it’s important to know how to handle these large amounts of data efficiently.Convolutional neural networks have been shown to solve image processing problems effectively.However,when designing the network structure for a particular problem,you need to adjust the hyperparameters for higher accuracy.This technique is time consuming and requires a lot of work and domain knowledge.Designing a convolutional neural network architecture is a classic NP-hard optimization challenge.On the other hand,different datasets require different combinations of models or hyperparameters,which can be time consuming and inconvenient.Various approaches have been proposed to overcome this problem,such as grid search limited to low-dimensional space and queuing by random selection.To address this issue,we propose an evolutionary algorithm-based approach that dynamically enhances the structure of Convolution Neural Networks(CNNs)using optimized hyperparameters.This study proposes a method using Non-dominated sorted genetic algorithms(NSGA)to improve the hyperparameters of the CNN model.In addition,different types and parameter ranges of existing genetic algorithms are used.Acomparative study was conducted with various state-of-the-art methodologies and algorithms.Experiments have shown that our proposed approach is superior to previous methods in terms of classification accuracy,and the results are published in modern computing literature.
基金Funded by the Planning Project of National Language Committee in the "12th 5-year Plan"(No.YB125-49)the Foundation for Key Program of Ministry of Education,China(No.212167)the Fundamental Research Funds for the Central Universities(No.SWJTU12CX096)
文摘How to quickly and accurately detect new topics from massive data online becomes a main problem of public opinion monitoring in cyberspace. This paperpresents a new event detection method for the current new event detection system, based on sorted subtopic matching algorithm and constructs the entire design framework. In this p^per, the subtopics contained in old topics （or news stories） are sorted in descending order according to their importance to the topic（or news stories）, and form a sorted subtopic sequence. In the process of subtopic matching, subtopic scoring matrix is used to determine whether a new story is reporting a new event. Experimental results show that the sorted subtopic matching model improved the accuracy and effectiveness ofthenew event detection system in cyberspace.
文摘A new file assignment strategy of parallel I/O, which is named heuristic file sorted assignment algorithm was proposed on cluster computing system. Based on the load balancing, it assigns the files to the same disk according to the similar service time. Firstly, the files were sorted and stored at the set I in descending order in terms of their service time, then one disk of cluster node was selected randomly when the files were to be assigned, and at last the continuous files were taken orderly from the set I to the disk until the disk reached its load maximum. The experimental results show that the new strategy improves the performance by 20.2% when the load of the system is light and by 31.6% when the load is heavy. And the higher the data access rate, the more evident the improvement of the performance obtained by the heuristic file sorted assignment algorithm.
文摘The purpose of this study is to analyze the household waste reduction effect of sorted collection of recyclable waste in Japan using a panel data analysis, which considers time-series and cross-section data simultaneously. Also, the study shows the effect of the type of sorted items on the quantity of household waste disposed. We used the data attained from 103 cities recorded over three years, and applied the quantity of total waste disposed, the quantity of combustible waste, the quantity of other waste （waste excluding combustible and recyclable waste）, and the quantity of combustible plus other waste as objective variables, respectively, in the models. The result suggests that when the number of sorted items is increased marginally, the quantity of household waste decreases by about 0.5%-3.3% or 1.28-4.17 grams per capita per day. In addition, it is shown that sorting out white trays is effective in reducing the quantity of combustible waste. Sorting out paper containers and packages is also effective in reducing the quantity of other waste and combustible plus other waste.
文摘“See it, Say it, Sorted.”就是告诉乘客,你要是看到了什么可疑的行为,就找工作人员说出来,我们协助你解决。2005年,在伦敦经历了地铁恐怖袭击之后,英国国家铁路(NationalRail)和英国交通警察局(British Transport Police)与安全专家、传播学者以及广告创意团队进行了多次讨论与头脑风暴。团队希望创造出一条易于理解、易于记忆,同时能促使行动的标语,“Seeit.Say it. Sorted.”由此诞生。
基金partially supported by European Research Council,the National Natural Science Foundation of China(No.11201079)the Fundamental Research Funds for the Central Universities of China(Nos.20520133238 and 20520131169)the National Natural Science Foundation of United States(Nos.DMS-0748839 and DMS-1317602).
文摘The l1 norm is the tight convex relaxation for the l0 norm and has been successfully applied for recovering sparse signals.However,for problems with fewer samples than required for accurate l1 recovery,one needs to apply nonconvex penalties such as lp norm.As one method for solving lp minimization problems,iteratively reweighted l1 minimization updates the weight for each component based on the value of the same component at the previous iteration.It assigns large weights on small components in magnitude and small weights on large components in magnitude.The set of the weights is not fixed,and it makes the analysis of this method difficult.In this paper,we consider a weighted l1 penalty with the set of the weights fixed,and the weights are assigned based on the sort of all the components in magnitude.The smallest weight is assigned to the largest component in magnitude.This new penalty is called nonconvex sorted l1.Then we propose two methods for solving nonconvex sorted l1 minimization problems:iteratively reweighted l1 minimization and iterative sorted thresholding,and prove that both methods will converge to a local minimizer of the nonconvex sorted l1 minimization problems.We also show that both methods are generalizations of iterative support detection and iterative hard thresholding,respectively.The numerical experiments demonstrate the better performance of assigning weights by sort compared to assigning by value.
文摘Sorted constraint representation is a very useful representation in AI which combines class hierarchies and constraint networks. For such sorted constraint representation, a problem is how to generalize the idea of default inheritance to constraint network, where the attributes in a class or between different classes interact with each other via the network. To give a formal account for the defeasible reasoning in such representation, a general sorted constraint logic is proposed, and a minimal-model semantics for the logic is presented.
基金National Natural Science Foundation of China,42103008,Hongming Cai。
文摘The majority(up to 90%)of riverine materials is transported from the continent to the ocean mainly in flood events.It is thus crucial to characterize the geochemistry of elements and their flux in river system in order to better constrain their global biogeochemical cycling and impact on the oceanic ecosystem.However,the geochemical behavior including the distribution,migration and partitioning of typical metal elements amongst diff erent phases,during hydrodynamic flood event remains still to be well explored.Here,we investigated the geochemical behaviors of typical metal elements in dissolved phase and suspended particulate matter collected from a single flood event in the natural Chishui River,Southwest China.The results showed clearly that the geochemistry of metal elements was largely controlled by the hydrodynamic eff ect,of which the diff erent flowrates introduce a natural sorting of diff erent mineral particles transported at diff erent flood stages,depending on their shape,size and density.The maximum concentrations of alkaline and alkaline earth metals(Li,Mg,K,Rb and Sr)in SPM appeared before the flood peak,which was largely controlled by aluminosilicate minerals.However,transition metals(Cr,Mn,Fe,Ni and Cu)showed their abundance peaks lagging behind the flowrate summit,as a result of the late arrival of coarse particles or heavy minerals,evidenced by the mineralogical phase analysis.In addition,the distribution coe fficient(K_(d))between particulate and dissolved loads were lower and stable for soluble alkali/alkaline earth metals which could be aff ected by pH,while higher and fluctuant for transition metals that were largely influenced by SPM content.Overall,the present study reveals clear eff ects of hydrodynamic sorting on the geochemistry of metal elements during the flood event of the natural Chishui River,which should be taken into account when characterizing the riverine flux and their impact on marine ecosystem.
基金research was funded bymultiple sources,including the Guangxi Natural Science Foundation of Youth Fund(2020GXNSFBA159004)the National Natural Science Foundation Project of China(51779204)the Guilin University of Technology High-Level Talent Research Startup Project(GUTQDJJ2018069).
文摘The particle size distribution plays a crucial role in the transportation and deposition of eroded sediments.Gaining insights into the related sorting mechanism can significantly enhance our understanding of such processes.In this study,sand-covered slopes were examined.A controlled indoor rainfall simulation was conducted on loess slopes with a 12°incline and a rainfall intensity of 1.5 mm/min.These slopes were then covered with sand layers of varying thicknesses—0.5,1.0,and 1.5 cm—to observe their effects.The findings have revealed that as the thickness of the sand cover increases,the content of sediment particles smaller than 0.054 mm decreases.In contrast,the content of particles larger than 0.054 mm increases after the sixth minute of runoff.The eroded sediment was predominantly composed of silt.During the inter-rill erosion stage,runoff primarily transported particles larger than 0.054 mm.However,in the subsequent rill erosion and combined rill and inter-rill erosion stages,the runoff predominantly carried finer particles,smaller than 0.054 mm.Moreover,the presence of the sand layer significantly influenced the size and form of the eroded sediment particles.Initially,during the first 10 min of runoff,the eroded particles were predominantly larger than 0.054 mm.After this period,however,the particle size shifted,with the majority of particles being smaller than 0.054 mm.This study highlights the intricate relationship between sediment sorting,the thickness of sand covers,and the dynamics of sediment transport under rainfall-induced erosion.
基金supported by the National Natural Science Foundation of China(No.32471608)the Open Project of Key Laboratory of Environmental Biotechnology,CAS(No.kf2020002)Yunnan Collaborative Innovation Center for Plateau Lake Ecology and Environmental Health.
文摘Elucidating the mechanisms underlying community assembly remains a central question in community ecology,especially in aquatic ecosystems disrupted by human activities.Understanding the causes and consequences of community responses to changing environment is essential for revealing the ecological effects of anthropogenic disturbances and proposing practical strategies for ecological restoration.While stochastic dispersal and species sorting are known to influence local biological communities,most studies have focused on horizontal dispersal,often neglecting the vertical exchange of organisms between planktonic and sedimentary communities when studying stochastic dispersal.We used a highly disturbed urban river in Beijing as a model system to investigate the relative roles of stochastic dispersal versus species sorting driven by local pollution,as well as two components of stochastic dispersal,vertical exchange and horizontal dispersal,in structuring local bacterial communities.Our integrated analyses of planktonic and sedimentary bacterial communities revealed that,despite different spatial patterns along the river,both types of bacterial communities were primarily shaped by stochastic dispersal processes rather than species sorting influenced by the environmental gradient.Notably,in addition to the effect of horizontal dispersal along the river,the vertical exchange between planktonic and sedimentary bacterial communities significantly contributed to the formation of local communities.These findings suggest that both vertical exchange and horizontal dispersal should be considered when assessing the role of stochastic dispersal in shaping local community structure in microbial communities.
基金Supported by Direktorat Riset dan Pengembangan(Directorate of Research and Development)Universitas Indonesia(NKB-690/UN2.RST/HKP.05.00/2022).
文摘The need to transport goods across countries and islands has resulted in a high demand for commercial vessels.Owing to such trends,shipyards must efficiently produce ships to reduce production costs.Layout and material flow are among the crucial aspects determining the efficiency of the production at a shipyard.This paper presents the initial design optimization of a shipyard layout using Nondominated Sorting Algorithm-Ⅱ(NSGA-Ⅱ)to find the optimal configuration of workstations in a shipyard layout.The proposed method focuses on simultaneously minimizing two material handling costs,namely work-based material handling and duration-based material handling.NSGA-Ⅱ determines the order of workstations in the shipyard layout.The semiflexible bay structure is then used in the workstation placement process from the sequence formed in NSGA-Ⅱ into a complete design.Considering that this study is a case of multiobjective optimization,the performance for both objectives at each iteration is presented in a 3D graph.Results indicate that after 500 iterations,the optimal configuration yields a work-based MHC of 163670.0 WBM-units and a duration-based MHC of 34750 DBM-units.Starting from a random solution,the efficiency of NSGA-Ⅱ demonstrates significant improvements,achieving a 50.19%reduction in work-based MHC and a 48.58%reduction in duration-based MHC.
基金supported by the Guizhou Province High-level Innovative Talent Project(Qiankehe Platform Talent-GCC[2022]027-1)the National Key Research and Development Program of China(2019YFA0904800).
文摘Soft rot is a destructive disease that inflicts significant losses on agricultural production and the economy post-harvest.Biocontrol strategies based on antagonistic microorganisms have a broad application prospect to fight against plant pathogens.This study utilized fluorescence-activated droplet sorting(FADS)technology as an alternative to traditional plate culture methods to isolate microorganisms with antagonistic activity against the soft rot pathogen Erwinia carotovora Ecc15.Initially,the culture performance of the FADS platform was evaluated by analyzing bacterial diversity in droplet culture samples and agar plate culture samples,our data showed that droplet culture exhibited higher species richness and diversity than plate culture,and more than 95%of the operational taxonomic units(OTUs)in the droplet samples belonged to the rare biosphere.Additionally,we developed a green fluorescent protein(GFP)-Ecc15-based FADS screening system,which achieved an enrichment ratio of up to 148.Using this system,we successfully screened 32 antagonistic bacteria from rhizosphere soil sample of healthy konjac plants,and some may be novel microbial resources,including the genera Lelliottia,Buttiauxella and Leclercia.Notably,strain D-62 exhibited the strongest antibacterial ability against Ecc15,with an inhibition zone diameter of(20.86±1.56)mm.In vivo experiments conducted on the corms of Amorphophallus konjac demonstrated that strain D-62 could effectively reduce the infection ability of Ecc15 to the corms,indicating that strain D-62 has the potential to be developed as a biocontrol agent.Our findings suggested that the FADS screening system showed a screening efficiency approximately 3×10^(3)times higher than plate screening system,while significantly reducing costs of infrastructure,labor and consumables,it provides theoretical guidance for the screening of other plant pathogen biocontrol bacteria.
文摘本文聚焦于基于多目标跟踪的课堂人数自动统计这一主题,提出将YOLOv8和SORT (Simple Online and Realtime Tracking)算法相结合的方法。其中,YOLOv8作为先进的单阶段目标检测算法,能迅速识别图像或视频帧中的目标并输出关键信息;SORT算法借助卡尔曼滤波预测目标位置变化。研究通过运用特定的软硬件配置开展实验,对模型进行训练与验证。该方法旨在实现课堂人数的精准自动统计,满足课堂管理和动态监控的需求,为教师及管理人员提供有力工具。其不仅在算法应用上具有创新性,而且在教育管理实践中具有重要的实用价值,有望对智慧教育领域的课堂管理产生积极深远的影响。This paper focuses on the theme of automatic counting of the number of people in the classroom based on multi-object tracking and proposes a method that combines the YOLOv8 and SORT algorithms. Among them, YOLOv8, as an advanced single-stage target detection algorithm, can quickly identify targets in an image or video frame and output key information. The SORT algorithm predicts the position change of the target with the help of Kalman filtering. The research conducts experiment by using specific software and hardware configurations to train and validate the model. This method aims to achieve accurate automatic counting of the number of people in the classroom, meet the needs of classroom management and dynamic monitoring, and provide a powerful tool for teachers and administrators. It is not only innovative in algorithm application, but also has important practical value in educational management practice, and is expected to have a positive and far-reaching impact on classroom management in the field of smart education.
文摘煤矿井下安全生产是保障矿工生命安全和能源稳定供应的核心环节,但传统监控方法在检测实时性和准确性方面存在明显不足。针对复杂井下环境中人员入侵识别精度低的问题,研究提出一种基于改进You Only Look Once version 5(YOLOv5)和深度简单在线实时跟踪算法的电子围栏入侵检测技术。研究通过嵌入注意力机制增强模型对关键特征的感知能力,并利用扩展卡尔曼滤波与匈牙利算法提升跟踪稳定性。实验结果表明,改进后的模型的识别率最高,且随迭代次数的增加其识别率始终在90%以上。该技术在识别性能上,平均精度均值指标为92.5%,每秒帧数提升至116.7,训练时长缩短至8.5 h,漏检率显著降低。研究表明,该方法在光照不均、煤尘干扰等复杂场景下具备更高的检测精度与实时性。该技术的提出可为煤矿井下智能化安全管理提供有效技术支撑,从而提高煤矿安全生产水平,杜绝生产事故出现。
