期刊文献+
共找到6,543篇文章
< 1 2 250 >
每页显示 20 50 100
The Perception of Locals and Visitors for Development on Internal Transports of Sukhothai Historical Park
1
作者 Pakin Witchayakawin Raktibul Chantanupan 《Journal of Tourism and Hospitality Management》 2018年第2期39-46,共8页
This qualitative research aims to study the perception of locals and inbound visitors to develop the internal transport of Sukhothai Historical Park.The primary data were collected by observation,in-depth interview,an... This qualitative research aims to study the perception of locals and inbound visitors to develop the internal transport of Sukhothai Historical Park.The primary data were collected by observation,in-depth interview,and small group discussion from the key informants that include 19 locals and 17 visitors during November 2017 by purposive sampling.The data were analyzed by content analysis,categorizing,and thematising.The findings present the perception and attitudes of locals and visitors towards the internal transport as well as its problems of the Sukhothai Historical Park.By analysis of the collected data,the authors of this paper offer some solutions to develop and improve the park’s internal transport in several ways. 展开更多
关键词 PERCEPTION locals and VISITORS INTERNAL TRANSPORTS Sukhothai HISTORICAL PARK
下载PDF
THE BLACK RIVER BRIDGE BRINGING PROSPERITY TO LOCALS
2
作者 Li Xiaohu 《China's Tibet》 2019年第3期38-41,共4页
'In the past, people always crossed the river by boat and would risk their lives doing it,' says Norbu Tashi, a villager from Xia in the town of Nenwa, Zoige County, as he observes the new Nenwa-Xiaman Bridge.... 'In the past, people always crossed the river by boat and would risk their lives doing it,' says Norbu Tashi, a villager from Xia in the town of Nenwa, Zoige County, as he observes the new Nenwa-Xiaman Bridge.'People have benefited a lot from this new bridge. It’s more convenient for cows, sheep, horses, and people to cross over, and it saves us trouble and worry while we’re busy going about our daily lives.' 展开更多
关键词 THE BLACK RIVER BRIDGE BRINGING PROSPERITY TO locals
下载PDF
Point Cloud Classification Using Content-Based Transformer via Clustering in Feature Space 被引量:2
3
作者 Yahui Liu Bin Tian +2 位作者 Yisheng Lv Lingxi Li Fei-Yue Wang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第1期231-239,共9页
Recently, there have been some attempts of Transformer in 3D point cloud classification. In order to reduce computations, most existing methods focus on local spatial attention,but ignore their content and fail to est... Recently, there have been some attempts of Transformer in 3D point cloud classification. In order to reduce computations, most existing methods focus on local spatial attention,but ignore their content and fail to establish relationships between distant but relevant points. To overcome the limitation of local spatial attention, we propose a point content-based Transformer architecture, called PointConT for short. It exploits the locality of points in the feature space(content-based), which clusters the sampled points with similar features into the same class and computes the self-attention within each class, thus enabling an effective trade-off between capturing long-range dependencies and computational complexity. We further introduce an inception feature aggregator for point cloud classification, which uses parallel structures to aggregate high-frequency and low-frequency information in each branch separately. Extensive experiments show that our PointConT model achieves a remarkable performance on point cloud shape classification. Especially, our method exhibits 90.3% Top-1 accuracy on the hardest setting of ScanObjectN N. Source code of this paper is available at https://github.com/yahuiliu99/PointC onT. 展开更多
关键词 Content-based Transformer deep learning feature aggregator local attention point cloud classification
下载PDF
Genome-wide investigation to assess copy number variants in the Italian local chicken population 被引量:1
4
作者 Filippo Cendron Martino Cassandro Mauro Penasa 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第2期563-577,共15页
Background Copy number variants(CNV)hold significant functional and evolutionary importance.Numerous ongoing CNV studies aim to elucidate the etiology of human diseases and gain insights into the population structure ... Background Copy number variants(CNV)hold significant functional and evolutionary importance.Numerous ongoing CNV studies aim to elucidate the etiology of human diseases and gain insights into the population structure of livestock.High-density chips have enabled the detection of CNV with increased resolution,leading to the identification of even small CNV.This study aimed to identify CNV in local Italian chicken breeds and investigate their distribution across the genome.Results Copy number variants were mainly distributed across the first six chromosomes and primarily associated with loss type CNV.The majority of CNV in the investigated breeds were of types 0 and 1,and the minimum length of CNV was significantly larger than that reported in previous studies.Interestingly,a high proportion of the length of chromosome 16 was covered by copy number variation regions(CNVR),with the major histocompatibility complex being the likely cause.Among the genes identified within CNVR,only those present in at least five animals across breeds(n=95)were discussed to reduce the focus on redundant CNV.Some of these genes have been associated to functional traits in chickens.Notably,several CNVR on different chromosomes harbor genes related to muscle development,tissue-specific biological processes,heat stress resistance,and immune response.Quantitative trait loci(QTL)were also analyzed to investigate potential overlapping with the identified CNVR:54 out of the 95 gene-containing regions overlapped with 428 QTL associated to body weight and size,carcass characteristics,egg production,egg components,fat deposition,and feed intake.Conclusions The genomic phenomena reported in this study that can cause changes in the distribution of CNV within the genome over time and the comparison of these differences in CNVR of the local chicken breeds could help in preserving these genetic resources. 展开更多
关键词 CHICKEN Copy number variant CONSERVATION Local breed SNP
下载PDF
A Study on the Transmission Dynamics of the Omicron Variant of COVID-19 Using Nonlinear Mathematical Models 被引量:1
5
作者 S.Dickson S.Padmasekaran +2 位作者 Pushpendra Kumar Kottakkaran Sooppy Nisar Hamidreza Marasi 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第6期2265-2287,共23页
This research examines the transmission dynamics of the Omicron variant of COVID-19 using SEIQIcRVW and SQIRV models,considering the delay in converting susceptible individuals into infected ones.The significant delay... This research examines the transmission dynamics of the Omicron variant of COVID-19 using SEIQIcRVW and SQIRV models,considering the delay in converting susceptible individuals into infected ones.The significant delays eventually resulted in the pandemic’s containment.To ensure the safety of the host population,this concept integrates quarantine and the COVID-19 vaccine.We investigate the stability of the proposed models.The fundamental reproduction number influences stability conditions.According to our findings,asymptomatic cases considerably impact the prevalence of Omicron infection in the community.The real data of the Omicron variant from Chennai,Tamil Nadu,India,is used to validate the outputs. 展开更多
关键词 Omicron local stability reproduction number steady states global stability
下载PDF
Multi-Material Topology Optimization for Spatial-Varying Porous Structures 被引量:1
6
作者 Chengwan Zhang Kai Long +4 位作者 Zhuo Chen Xiaoyu Yang Feiyu Lu Jinhua Zhang Zunyi Duan 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第1期369-390,共22页
This paper aims to propose a topology optimization method on generating porous structures comprising multiple materials.The mathematical optimization formulation is established under the constraints of individual volu... This paper aims to propose a topology optimization method on generating porous structures comprising multiple materials.The mathematical optimization formulation is established under the constraints of individual volume fraction of constituent phase or total mass,as well as the local volume fraction of all phases.The original optimization problem with numerous constraints is converted into a box-constrained optimization problem by incorporating all constraints to the augmented Lagrangian function,avoiding the parameter dependence in the conventional aggregation process.Furthermore,the local volume percentage can be precisely satisfied.The effects including the globalmass bound,the influence radius and local volume percentage on final designs are exploited through numerical examples.The numerical results also reveal that porous structures keep a balance between the bulk design and periodic design in terms of the resulting compliance.All results,including those for irregular structures andmultiple volume fraction constraints,demonstrate that the proposedmethod can provide an efficient solution for multiple material infill structures. 展开更多
关键词 Topology optimization porous structures local volume fraction augmented lagrangian multiple materials
下载PDF
Deep brain implantable microelectrode arrays for detection and functional localization of the subthalamic nucleus in rats with Parkinson’s disease 被引量:1
7
作者 Luyi Jing Zhaojie Xu +11 位作者 Penghui Fan Botao Lu Fan Mo Ruilin Hu Wei Xu Jin Shan Qianli Jia Yuxin Zhu Yiming Duan Mixia Wang Yirong Wu Xinxia Cai 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2024年第4期439-452,共14页
The subthalamic nucleus(STN)is considered the best target for deep brain stimulation treatments of Parkinson’s disease(PD).It is difficult to localize the STN due to its small size and deep location.Multichannel micr... The subthalamic nucleus(STN)is considered the best target for deep brain stimulation treatments of Parkinson’s disease(PD).It is difficult to localize the STN due to its small size and deep location.Multichannel microelectrode arrays(MEAs)can rapidly and precisely locate the STN,which is important for precise stimulation.In this paper,16-channel MEAs modified with multiwalled carbon nanotube/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate)(MWCNT/PEDOT:PSS)nanocomposites were designed and fabricated,and the accurate and rapid identification of the STN in PD rats was performed using detection sites distributed at different brain depths.These results showed that nuclei in 6-hydroxydopamine hydrobromide(6-OHDA)-lesioned brains discharged more intensely than those in unlesioned brains.In addition,the MEA simultaneously acquired neural signals from both the STN and the upper or lower boundary nuclei of the STN.Moreover,higher values of spike firing rate,spike amplitude,local field potential(LFP)power,and beta oscillations were detected in the STN of the 6-OHDA-lesioned brain,and may therefore be biomarkers of STN localization.Compared with the STNs of unlesioned brains,the power spectral density of spikes and LFPs synchronously decreased in the delta band and increased in the beta band of 6-OHDA-lesioned brains.This may be a cause of sleep and motor disorders associated with PD.Overall,this work describes a new cellular-level localization and detection method and provides a tool for future studies of deep brain nuclei. 展开更多
关键词 Functional localization Implantable microelectrode arrays Parkinson’s disease Subthalamic nucleus
下载PDF
Mechanistic investigation on Ag-Cu_(2)O in electrocatalytic CO_(2) to CH_(4) by in situ/operando spectroscopic and theoretical analysis 被引量:1
8
作者 Min Sun Luxiao Zhang +10 位作者 Fuli Tian Jiaxin Li Yanqiu Lei Heng Zhang Lifeng Han Zhihua Guo Yonghui Gao Fenrong Liu Yan Wang Luhui Wang Shanghong Zeng 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第1期521-531,I0012,共12页
Silver-copper electrocatalysts have demonstrated effectively catalytic performance in electroreduction CO_(2) toward CH_(4),yet a revealing insight into the reaction pathway and mechanism has remained elusive.Herein,w... Silver-copper electrocatalysts have demonstrated effectively catalytic performance in electroreduction CO_(2) toward CH_(4),yet a revealing insight into the reaction pathway and mechanism has remained elusive.Herein,we construct chemically bonded Ag-Cu_(2)O boundaries,in which the complete reduction of Cu_(2)O to Cu has been strongly impeded owing to the presence of surface Ag shell.The interfacial confinement effect helps to maintain Cu^(+)sites at the Ag-Cu_(2)O boundaries.Using in situ/operando spectroscopy and theoretical simulations,it is revealed that CO_(2) is enriched at the Ag-Cu_(2)O boundaries due to the enhanced physisorption and chemisorption to CO_(2),activating CO_(2) to form the stable intermediate^(*)CO.The boundaries between Ag shell and the Cu_(2)O mediate local^(*)CO coverage and promote^(*)CHO intermediate formation,consequently facilitating CO_(2)-to-CH_(4) conversion.This work not only reveals the structure-activity relationships but also offers insights into the reaction mechanism on Ag-Cu catalysts for efficient electrocatalytic CO_(2) reduction. 展开更多
关键词 Ag shell Interfacial confinement effect Cu~+ Local*CO coverage CO_(2)reduction
下载PDF
Construction of a Computational Scheme for the Fuzzy HIV/AIDS Epidemic Model with a Nonlinear Saturated Incidence Rate 被引量:1
9
作者 Muhammad Shoaib Arif Kamaleldin Abodayeh Yasir Nawaz 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第2期1405-1425,共21页
This work aimed to construct an epidemic model with fuzzy parameters.Since the classical epidemic model doesnot elaborate on the successful interaction of susceptible and infective people,the constructed fuzzy epidemi... This work aimed to construct an epidemic model with fuzzy parameters.Since the classical epidemic model doesnot elaborate on the successful interaction of susceptible and infective people,the constructed fuzzy epidemicmodel discusses the more detailed versions of the interactions between infective and susceptible people.Thenext-generation matrix approach is employed to find the reproduction number of a deterministic model.Thesensitivity analysis and local stability analysis of the systemare also provided.For solving the fuzzy epidemic model,a numerical scheme is constructed which consists of three time levels.The numerical scheme has an advantage overthe existing forward Euler scheme for determining the conditions of getting the positive solution.The establishedscheme also has an advantage over existing non-standard finite difference methods in terms of order of accuracy.The stability of the scheme for the considered fuzzy model is also provided.From the plotted results,it can beobserved that susceptible people decay by rising interaction parameters. 展开更多
关键词 Epidemic model fuzzy rate parameters next generation matrix local stability proposed numerical scheme
下载PDF
Present situation and prospect of immunotherapy for unresectable locally advanced esophageal cancer during peri-radiotherapy 被引量:1
10
作者 Feng-Mei Wang Peng Mo +2 位作者 Xue Yan Xin-Yue Lin Zhi-Chao Fu 《World Journal of Gastrointestinal Oncology》 SCIE 2024年第1期1-7,共7页
Four major studies(Checkmate577,Keynote-590,Checkmate649 and Attraction-4)of locally advanced esophageal cancer published in 2020 have established the importance of immunotherapy,represented by anti-programmed death p... Four major studies(Checkmate577,Keynote-590,Checkmate649 and Attraction-4)of locally advanced esophageal cancer published in 2020 have established the importance of immunotherapy,represented by anti-programmed death protein(PD)-1 in postoperative adjuvant treatment and advanced first-line treatment of locally advanced or advanced esophageal cancer and esophagogastric junction cancer,from the aspects of proof of concept,long-term survival,overall survival rate and progression-free survival.For unresectable or inoperable nonmetastatic esophageal cancer,concurrent radiotherapy and chemotherapy is the standard treatment recommended by various guidelines.Because its curative effect is still not ideal,it is necessary to explore radical radiotherapy and chemotherapy in the future,and it is considered to be promising to combine them with immunotherapeutic drugs such as anti-PD-1.This paper mainly discusses how to combine radical concurrent radiotherapy and chemotherapy with immunotherapy for unresectable local advanced esophageal cancer. 展开更多
关键词 Esophageal carcinoma Locally advanced RADIOTHERAPY IMMUNOTHERAPY
下载PDF
Cooperative Anti-Jamming and Interference Mitigation for UAV Networks: A Local Altruistic Game Approach 被引量:1
11
作者 Yueyue Su Nan Qi +2 位作者 Zanqi Huang Rugui Yao Luliang Jia 《China Communications》 SCIE CSCD 2024年第2期183-196,共14页
To improve the anti-jamming and interference mitigation ability of the UAV-aided communication systems, this paper investigates the channel selection optimization problem in face of both internal mutual interference a... To improve the anti-jamming and interference mitigation ability of the UAV-aided communication systems, this paper investigates the channel selection optimization problem in face of both internal mutual interference and external malicious jamming. A cooperative anti-jamming and interference mitigation method based on local altruistic is proposed to optimize UAVs’ channel selection. Specifically, a Stackelberg game is modeled to formulate the confrontation relationship between UAVs and the jammer. A local altruistic game is modeled with each UAV considering the utilities of both itself and other UAVs. A distributed cooperative anti-jamming and interference mitigation algorithm is proposed to obtain the Stackelberg equilibrium. Finally, the convergence of the proposed algorithm and the impact of the transmission power on the system loss value are analyzed, and the anti-jamming performance of the proposed algorithm can be improved by around 64% compared with the existing algorithms. 展开更多
关键词 channel selection cooperative antijamming and interference mitigation local altruistic game Stackelberg game unmanned aerial vehicle(UAV)
下载PDF
Monitoring seismicity in the southern Sichuan Basin using a machine learning workflow 被引量:1
12
作者 Kang Wang Jie Zhang +2 位作者 Ji Zhang Zhangyu Wang Huiyu Zhu 《Earthquake Research Advances》 CSCD 2024年第1期59-66,共8页
Monitoring seismicity in real time provides significant benefits for timely earthquake warning and analyses.In this study,we propose an automatic workflow based on machine learning(ML)to monitor seismicity in the sout... Monitoring seismicity in real time provides significant benefits for timely earthquake warning and analyses.In this study,we propose an automatic workflow based on machine learning(ML)to monitor seismicity in the southern Sichuan Basin of China.This workflow includes coherent event detection,phase picking,and earthquake location using three-component data from a seismic network.By combining Phase Net,we develop an ML-based earthquake location model called Phase Loc,to conduct real-time monitoring of the local seismicity.The approach allows us to use synthetic samples covering the entire study area to train Phase Loc,addressing the problems of insufficient data samples,imbalanced data distribution,and unreliable labels when training with observed data.We apply the trained model to observed data recorded in the southern Sichuan Basin,China,between September 2018 and March 2019.The results show that the average differences in latitude,longitude,and depth are 5.7 km,6.1 km,and 2 km,respectively,compared to the reference catalog.Phase Loc combines all available phase information to make fast and reliable predictions,even if only a few phases are detected and picked.The proposed workflow may help real-time seismic monitoring in other regions as well. 展开更多
关键词 Earthquake monitoring Machine learning Local seismicity Gaussian waveform Sparse stations
下载PDF
Numerical study on local scour characteristics around submarine pipelines in the Yellow River Delta silty sandy soil under waves and currents 被引量:1
13
作者 Peng Yu Ruigeng Hu +4 位作者 Jike Zhang Qi Yang Jieru Zhao Lei Cao Chenghao Zhu 《Deep Underground Science and Engineering》 2024年第2期182-196,共15页
Due to their high reliability and cost-efficiency,submarine pipelines are widely used in offshore oil and gas resource engineering.Due to the interaction of waves,currents,seabed,and pipeline structures,the soil aroun... Due to their high reliability and cost-efficiency,submarine pipelines are widely used in offshore oil and gas resource engineering.Due to the interaction of waves,currents,seabed,and pipeline structures,the soil around submarine pipelines is prone to local scour,severely affecting their operational safety.With the Yellow River Delta as the research area and based on the renormalized group(RNG)k-εturbulence model and Stokes fifth-order wave theory,this study solves the Navier-Stokes(N-S)equation using the finite difference method.The volume of fluid(VOF)method is used to describe the fluid-free surface,and a threedimensional numerical model of currents and waves-submarine pipeline-silty sandy seabed is established.The rationality of the numerical model is verified using a self-built waveflow flume.On this basis,in this study,the local scour development and characteristics of submarine pipelines in the Yellow River Delta silty sandy seabed in the prototype environment are explored and the influence of the presence of pipelines on hydrodynamic features such as surrounding flow field,shear stress,and turbulence intensity is analyzed.The results indicate that(1)local scour around submarine pipelines can be divided into three stages:rapid scour,slow scour,and stable scour.The maximum scour depth occurs directly below the pipeline,and the shape of the scour pits is asymmetric.(2)As the water depth decreases and the pipeline suspension height increases,the scour becomes more intense.(3)When currents go through a pipeline,a clear stagnation point is formed in front of the pipeline,and the flow velocity is positively correlated with the depth of scour.This study can provide a valuable reference for the protection of submarine pipelines in this area. 展开更多
关键词 local scour numerical simulation submarine pipelines Yellow River Delta
下载PDF
Ultrafast dynamics of femtosecond laser-induced high spatial frequency periodic structures on silicon surfaces 被引量:1
14
作者 Ruozhong Han Yuchan Zhang +6 位作者 Qilin Jiang Long Chen Kaiqiang Cao Shian Zhang Donghai Feng Zhenrong Sun Tianqing Jia 《Opto-Electronic Science》 2024年第3期33-46,共14页
Femtosecond laser-induced periodic surface structures(LIPSS)have been extensively studied over the past few decades.In particular,the period and groove width of high-spatial-frequency LIPSS(HSFL)is much smaller than t... Femtosecond laser-induced periodic surface structures(LIPSS)have been extensively studied over the past few decades.In particular,the period and groove width of high-spatial-frequency LIPSS(HSFL)is much smaller than the diffraction limit,making it a useful method for efficient nanomanufacturing.However,compared with the low-spatial-frequency LIPSS(LSFL),the structure size of the HSFL is smaller,and it is more easily submerged.Therefore,the formation mechanism of HSFL is complex and has always been a research hotspot in this field.In this study,regular LSFL with a period of 760 nm was fabricated in advance on a silicon surface with two-beam interference using an 800 nm,50 fs femtosecond laser.The ultrafast dynamics of HSFL formation on the silicon surface of prefabricated LSFL under single femtosecond laser pulse irradiation were observed and analyzed for the first time using collinear pump-probe imaging method.In general,the evolution of the surface structure undergoes five sequential stages:the LSFL begins to split,becomes uniform HSFL,degenerates into an irregular LSFL,undergoes secondary splitting into a weakly uniform HSFL,and evolves into an irregular LSFL or is submerged.The results indicate that the local enhancement of the submerged nanocavity,or the nanoplasma,in the prefabricated LSFL ridge led to the splitting of the LSFL,and the thermodynamic effect drove the homogenization of the splitting LSFL,which evolved into HSFL. 展开更多
关键词 laser-induced periodic surface structures(LIPSS) local field enhancement collinear pump-probe imaging silicon high spatial frequency periodic structures
下载PDF
Biodiversity responses to insular fragmentation in Amazonia: Two decades of research in the Balbina Hydroelectric Reservoir 被引量:1
15
作者 Ana Filipa Palmeirim Maíra Benchimol +4 位作者 Danielle Storck-Tonon Anderson S.Bueno Isabel L.Jones Gilmar Klein Carlos A.Peres 《Zoological Research(Diversity and Conservation)》 2024年第2期106-116,共11页
As hydropower development expands across lowland tropical forests,flooding and concomitant insular fragmentation have become important threats to biodiversity.Newly created insular landscapes serve as natural laborato... As hydropower development expands across lowland tropical forests,flooding and concomitant insular fragmentation have become important threats to biodiversity.Newly created insular landscapes serve as natural laboratories to investigate biodiversity responses to fragmentation.One of these most iconic landscapes is the Balbina Hydroelectric Reservoir in Brazilian Amazonia,occupying>400000 ha and comprising>3500 forest islands.Here,we synthesise the current knowledge on responses of a wide range of biological groups to insular fragmentation at Balbina.Sampling has largely concentrated on a set of 22 islands and three mainland sites.In total,39 studies were conducted over nearly two decades,covering 17 vertebrate,invertebrate,and plant taxa.Although species responses varied according to taxonomic group,island area was consistently included and played a pivotal role in 66.7%of all studies examining patterns of species diversity.Species persistence was further affected by species traits,mostly related to species capacity to use/traverse the aquatic matrix or tolerate habitat degradation,as noted for species of vertebrates and orchid bees.Further research is needed to improve our understanding of such effects on wider ecosystem functioning.Environmental Impact Assessments must account for changes in both the remaining habitat amount and configuration,and subsequent long-term species losses. 展开更多
关键词 Habitat loss Hydropower dams Landbridge Local extinctions Species-area relationships Species diversity Tropical forests
下载PDF
SNR and RSSI Based an Optimized Machine Learning Based Indoor Localization Approach:Multistory Round Building Scenario over LoRa Network
16
作者 Muhammad Ayoub Kamal Muhammad Mansoor Alam +1 位作者 Aznida Abu Bakar Sajak Mazliham Mohd Su’ud 《Computers, Materials & Continua》 SCIE EI 2024年第8期1927-1945,共19页
In situations when the precise position of a machine is unknown,localization becomes crucial.This research focuses on improving the position prediction accuracy over long-range(LoRa)network using an optimized machine ... In situations when the precise position of a machine is unknown,localization becomes crucial.This research focuses on improving the position prediction accuracy over long-range(LoRa)network using an optimized machine learning-based technique.In order to increase the prediction accuracy of the reference point position on the data collected using the fingerprinting method over LoRa technology,this study proposed an optimized machine learning(ML)based algorithm.Received signal strength indicator(RSSI)data from the sensors at different positions was first gathered via an experiment through the LoRa network in a multistory round layout building.The noise factor is also taken into account,and the signal-to-noise ratio(SNR)value is recorded for every RSSI measurement.This study concludes the examination of reference point accuracy with the modified KNN method(MKNN).MKNN was created to more precisely anticipate the position of the reference point.The findings showed that MKNN outperformed other algorithms in terms of accuracy and complexity. 展开更多
关键词 Indoor localization MKNN LoRa machine learning classification RSSI SNR localization
下载PDF
Assessment of earthquake location uncertainties for the design of local seismic networks
17
作者 Antonio Fuggi Simone Re +3 位作者 Giorgio Tango Sergio Del Gaudio Alessandro Brovelli Giorgio Cassiani 《Earthquake Science》 2024年第5期415-433,共19页
The ability to estimate earthquake source locations,along with the appraisal of relevant uncertainties,is paramount in monitoring both natural and human-induced micro-seismicity.For this purpose,a monitoring network m... The ability to estimate earthquake source locations,along with the appraisal of relevant uncertainties,is paramount in monitoring both natural and human-induced micro-seismicity.For this purpose,a monitoring network must be designed to minimize the location errors introduced by geometrically unbalanced networks.In this study,we first review different sources of errors relevant to the localization of seismic events,how they propagate through localization algorithms,and their impact on outcomes.We then propose a quantitative method,based on a Monte Carlo approach,to estimate the uncertainty in earthquake locations that is suited to the design,optimization,and assessment of the performance of a local seismic monitoring network.To illustrate the performance of the proposed approach,we analyzed the distribution of the localization uncertainties and their related dispersion for a highly dense grid of theoretical hypocenters in both the horizontal and vertical directions using an actual monitoring network layout.The results expand,quantitatively,the qualitative indications derived from purely geometrical parameters(azimuthal gap(AG))and classical detectability maps.The proposed method enables the systematic design,optimization,and evaluation of local seismic monitoring networks,enhancing monitoring accuracy in areas proximal to hydrocarbon production,geothermal fields,underground natural gas storage,and other subsurface activities.This approach aids in the accurate estimation of earthquake source locations and their associated uncertainties,which are crucial for assessing and mitigating seismic risks,thereby enabling the implementation of proactive measures to minimize potential hazards.From an operational perspective,reliably estimating location accuracy is crucial for evaluating the position of seismogenic sources and assessing possible links between well activities and the onset of seismicity. 展开更多
关键词 network design earthquake localization DETECTABILITY localization uncertainties local seismic network
下载PDF
Improved PSO-Extreme Learning Machine Algorithm for Indoor Localization
18
作者 Qiu Wanqing Zhang Qingmiao +1 位作者 Zhao Junhui Yang Lihua 《China Communications》 SCIE CSCD 2024年第5期113-122,共10页
Wi Fi and fingerprinting localization method have been a hot topic in indoor positioning because of their universality and location-related features.The basic assumption of fingerprinting localization is that the rece... Wi Fi and fingerprinting localization method have been a hot topic in indoor positioning because of their universality and location-related features.The basic assumption of fingerprinting localization is that the received signal strength indication(RSSI)distance is accord with the location distance.Therefore,how to efficiently match the current RSSI of the user with the RSSI in the fingerprint database is the key to achieve high-accuracy localization.In this paper,a particle swarm optimization-extreme learning machine(PSO-ELM)algorithm is proposed on the basis of the original fingerprinting localization.Firstly,we collect the RSSI of the experimental area to construct the fingerprint database,and the ELM algorithm is applied to the online stages to determine the corresponding relation between the location of the terminal and the RSSI it receives.Secondly,PSO algorithm is used to improve the bias and weight of ELM neural network,and the global optimal results are obtained.Finally,extensive simulation results are presented.It is shown that the proposed algorithm can effectively reduce mean error of localization and improve positioning accuracy when compared with K-Nearest Neighbor(KNN),Kmeans and Back-propagation(BP)algorithms. 展开更多
关键词 extreme learning machine fingerprinting localization indoor localization machine learning particle swarm optimization
下载PDF
基于Local Cascade Ensemble方法的胎儿健康自动分类
19
作者 黄梅佳 李宗辉 郑博伟 《信息技术与信息化》 2024年第4期122-125,共4页
为更好地自动评估胎儿宫内状态,提出一种基于local cascade ensemble(LCE)方法的胎儿健康状态分类模型。选用UCI数据集,使用ADASYN方法对不平衡数据集进行填充平衡,接着结合随机森林算法对数据特征进行选择,最后使用LCE方法对胎儿状态... 为更好地自动评估胎儿宫内状态,提出一种基于local cascade ensemble(LCE)方法的胎儿健康状态分类模型。选用UCI数据集,使用ADASYN方法对不平衡数据集进行填充平衡,接着结合随机森林算法对数据特征进行选择,最后使用LCE方法对胎儿状态进行自动分类。实验结果表明,所提出模型使用的方法平均准确率、精确率、召回率和F1分数分别达到了0.9554、0.9054、0.9557和0.9290,对比传统的机器学习算法能得到更好的分类效果,有效降低了误判率。 展开更多
关键词 机器学习 胎儿监护 自动分类 Local Cascade Ensemble
下载PDF
Observation of HⅠaround three Satellite Galaxies of M31 with FAST:AndromedaⅡ,NGC 205,and NGC 185
20
作者 Ziming Liu Jie Wang +6 位作者 Yingjie Jing Chen Xu Tiantian Liang Qingze Chen Zerui Liu Zhipeng Hou Yougang Wang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第8期52-59,共8页
With the exceptional sensitivity of the Five-hundred-meter Aperture Spherical radio Telescope,we conducted observations of the neutral hydrogen(HⅠ)in the circumgalactic medium of Andromeda’s(M31)satellite galaxies,s... With the exceptional sensitivity of the Five-hundred-meter Aperture Spherical radio Telescope,we conducted observations of the neutral hydrogen(HⅠ)in the circumgalactic medium of Andromeda’s(M31)satellite galaxies,specifically AndromedaⅡ,NGC 205,and NGC 185.Initially,three drift scans were executed for these satellites,with a detection limit of 4×10^(18)cm^(-2)(approximately 1.88×10^(3)M_Θof HⅠmass),followed by a more in-depth scan of a specific region.We discovered a C-shaped HⅠarc structure sharing a position and line-of-sight velocity similar to a stellar ring structure around AndromedaⅡ,hinting at a potential connection with AndromedaⅡ.In the context of NGC 205,we identified two mass concentrations in the northeast direction,which could be indicative of tidal streams resulting from the interaction between this galaxy and M31.These new lumps discovered could be very helpful in solving the missing interstellar medium problem for NGC 205.Observations regarding NGC 185are consistent with previous studies,and we did not detect any additional HⅠmaterial around this galaxy.These observational results enhance our understanding of the evolution of these satellite galaxies and provide insight into their historical interactions with the galaxy M31. 展开更多
关键词 ISM structure-(Galaxy)local interstellar matter-galaxies interactions-galaxies ISM-(galaxies)Local Group-radio lines ISM-radio lines GALAXIES
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部