To address the imbalance problem between supply and demand for taxis and passengers,this paper proposes a distributed ensemble empirical mode decomposition with normalization of spatial attention mechanism based bi-di...To address the imbalance problem between supply and demand for taxis and passengers,this paper proposes a distributed ensemble empirical mode decomposition with normalization of spatial attention mechanism based bi-directional gated recurrent unit(EEMDN-SABiGRU)model on Spark for accurate passenger hotspot prediction.It focuses on reducing blind cruising costs,improving carrying efficiency,and maximizing incomes.Specifically,the EEMDN method is put forward to process the passenger hotspot data in the grid to solve the problems of non-smooth sequences and the degradation of prediction accuracy caused by excessive numerical differences,while dealing with the eigenmodal EMD.Next,a spatial attention mechanism is constructed to capture the characteristics of passenger hotspots in each grid,taking passenger boarding and alighting hotspots as weights and emphasizing the spatial regularity of passengers in the grid.Furthermore,the bi-directional GRU algorithm is merged to deal with the problem that GRU can obtain only the forward information but ignores the backward information,to improve the accuracy of feature extraction.Finally,the accurate prediction of passenger hotspots is achieved based on the EEMDN-SABiGRU model using real-world taxi GPS trajectory data in the Spark parallel computing framework.The experimental results demonstrate that based on the four datasets in the 00-grid,compared with LSTM,EMDLSTM,EEMD-LSTM,GRU,EMD-GRU,EEMD-GRU,EMDN-GRU,CNN,and BP,the mean absolute percentage error,mean absolute error,root mean square error,and maximum error values of EEMDN-SABiGRU decrease by at least 43.18%,44.91%,55.04%,and 39.33%,respectively.展开更多
Due to the acceleration of urbanization,the municipal waste(MW)problem has transformed into a global challenge for urb-an sustainability.To elucidate historical trends,current focal points,and future directions in MW ...Due to the acceleration of urbanization,the municipal waste(MW)problem has transformed into a global challenge for urb-an sustainability.To elucidate historical trends,current focal points,and future directions in MW research,we conducted a bibliometric analysis and employed knowledge graph visualization to scrutinize a total of 34212 articles,which were published between 1991 and 2021 in the Web of Science(WoS)core database.The results indicated that current major research themes encompass waste classifica-tion and recycling,waste management and public behavior,waste disposal methods and technologies,as well as environmental impact and evaluation.There has been a shift in the research focus from the environmental impacts of waste incineration to sustainable manage-ment related issues.A comparison of research from six typical countries revealed the differences in research priorities and techniques advantages.Scholars from the USA and Britain initiated MW research earlier than other countries and investigated management issues in depth,such as public behavior and willingness to pay.Meanwhile,Japanese,German,and Swedish scholars conducted extensive studies on advanced waste treatment technologies,such as disposal and recycling,risk assessment,and waste-to-energy techniques.Chinese scholars placed particular emphasis on end-of-pipe treatments and their associated environmental impacts.Hotspots and poten-tial future frontiers were identified by burst detection analysis.Keywords with high value of burst index(BI)worldwide are food waste and circular economy.Chinese scholars have put great efforts on waste environmental impact and its recycling technologies,while we’re expecting to further investigating vulnerable population.Furthermore,this study contributes to bridging the regional gap of scientific research among different countries and fostering international collaboration.展开更多
Aim The purpose of this study was to explore the application status of natural products in osteoporosis research and explore its research hotspots and future research directions by analyzing the literature in the fiel...Aim The purpose of this study was to explore the application status of natural products in osteoporosis research and explore its research hotspots and future research directions by analyzing the literature in the field of natural products therapy for osteoporosis from 2000 to 2021.Method Publications on natural products in osteoporosis research were extracted from the Web of Science core collection database.Bibliometrics package in R language,VOSviewer and CiteSpace software were used for visualization analysis.Result From 2000 to 2021,the number of articles on natural products in osteoporosis research was 1596,and the total number of articles increased rapidly.China was the driving force in this field,and the top-contributing institution was Guangzhou University of Chinese Medicine.Most publications were published in the Journal of Ethnopharmacology.While J.K.Xu and Y.Zhang were the most cited and co-cited author.Countries,research institutions and authors in different regions cooperate closely.The hot topics included osteoporosis,differentiation,expression,in vitro,cell,osteogenesis and osteogenesis were the research frontiers in recent years.Conclusion This study conducted a bibliometric visualization analysis on the research status,research hotspots and development trend of natural products in osteoporosis for the first time.In addition,this paper also puts forward suggestions and prospects for the future development of this field,which will help researchers to open up new directions for future research in this field.展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.62162012,62173278,and 62072061)the Science and Technology Support Program of Guizhou Province,China(No.QKHZC2021YB531)+3 种基金the Natural Science Research Project of Department of Education of Guizhou Province,China(Nos.QJJ2022015 and QJJ2022047)the Science and Technology Foundation of Guizhou Province,China(Nos.QKHJCZK2022YB195,QKHJCZK2022YB197,and QKHJCZK2023YB143)the Scientific Research Platform Project of Guizhou Minzu University,China(No.GZMUSYS202104)the 7^(th) Batch High-Level Innovative Talent Project of Guizhou Province,China。
文摘To address the imbalance problem between supply and demand for taxis and passengers,this paper proposes a distributed ensemble empirical mode decomposition with normalization of spatial attention mechanism based bi-directional gated recurrent unit(EEMDN-SABiGRU)model on Spark for accurate passenger hotspot prediction.It focuses on reducing blind cruising costs,improving carrying efficiency,and maximizing incomes.Specifically,the EEMDN method is put forward to process the passenger hotspot data in the grid to solve the problems of non-smooth sequences and the degradation of prediction accuracy caused by excessive numerical differences,while dealing with the eigenmodal EMD.Next,a spatial attention mechanism is constructed to capture the characteristics of passenger hotspots in each grid,taking passenger boarding and alighting hotspots as weights and emphasizing the spatial regularity of passengers in the grid.Furthermore,the bi-directional GRU algorithm is merged to deal with the problem that GRU can obtain only the forward information but ignores the backward information,to improve the accuracy of feature extraction.Finally,the accurate prediction of passenger hotspots is achieved based on the EEMDN-SABiGRU model using real-world taxi GPS trajectory data in the Spark parallel computing framework.The experimental results demonstrate that based on the four datasets in the 00-grid,compared with LSTM,EMDLSTM,EEMD-LSTM,GRU,EMD-GRU,EEMD-GRU,EMDN-GRU,CNN,and BP,the mean absolute percentage error,mean absolute error,root mean square error,and maximum error values of EEMDN-SABiGRU decrease by at least 43.18%,44.91%,55.04%,and 39.33%,respectively.
基金Under the auspices of the General Program of National Natural Science Foundation of China(No.42271112)General Research Project of Beijing Municipal Commission of Education Science(No.KM202011417008)。
文摘Due to the acceleration of urbanization,the municipal waste(MW)problem has transformed into a global challenge for urb-an sustainability.To elucidate historical trends,current focal points,and future directions in MW research,we conducted a bibliometric analysis and employed knowledge graph visualization to scrutinize a total of 34212 articles,which were published between 1991 and 2021 in the Web of Science(WoS)core database.The results indicated that current major research themes encompass waste classifica-tion and recycling,waste management and public behavior,waste disposal methods and technologies,as well as environmental impact and evaluation.There has been a shift in the research focus from the environmental impacts of waste incineration to sustainable manage-ment related issues.A comparison of research from six typical countries revealed the differences in research priorities and techniques advantages.Scholars from the USA and Britain initiated MW research earlier than other countries and investigated management issues in depth,such as public behavior and willingness to pay.Meanwhile,Japanese,German,and Swedish scholars conducted extensive studies on advanced waste treatment technologies,such as disposal and recycling,risk assessment,and waste-to-energy techniques.Chinese scholars placed particular emphasis on end-of-pipe treatments and their associated environmental impacts.Hotspots and poten-tial future frontiers were identified by burst detection analysis.Keywords with high value of burst index(BI)worldwide are food waste and circular economy.Chinese scholars have put great efforts on waste environmental impact and its recycling technologies,while we’re expecting to further investigating vulnerable population.Furthermore,this study contributes to bridging the regional gap of scientific research among different countries and fostering international collaboration.
基金This work was supported by the National Natural Science Foundation of China(81803690)the Natural Science Foundation of Heilongjiang Province(LH2021H097)+5 种基金Heilongjiang Touyan Innovation Team Program,the National Famous Old Traditional Chinese Medicine Experts Inheritance Studio Construction Program of National Administration of TCM([2022]No.75)The Seventh Batch of National Old Traditional Chinese Medicine Experts Academic Experience Inheritance Program([2022]No.76)the Innovative Talents Funding of Heilongjiang University of Chinese Medicine(2018RCD25)the National Natural Science Foundation Matching Project(2018PT02)Special Funds from the Central Finance to Support the Development of Local Universities,the Heilongjiang Postdoctoral Scientific Research Developmental Fund(LBH-Q16210)the Postdoctoral Initial Fund of Heilongjiang Province(UNPYSCT 2017219).
文摘Aim The purpose of this study was to explore the application status of natural products in osteoporosis research and explore its research hotspots and future research directions by analyzing the literature in the field of natural products therapy for osteoporosis from 2000 to 2021.Method Publications on natural products in osteoporosis research were extracted from the Web of Science core collection database.Bibliometrics package in R language,VOSviewer and CiteSpace software were used for visualization analysis.Result From 2000 to 2021,the number of articles on natural products in osteoporosis research was 1596,and the total number of articles increased rapidly.China was the driving force in this field,and the top-contributing institution was Guangzhou University of Chinese Medicine.Most publications were published in the Journal of Ethnopharmacology.While J.K.Xu and Y.Zhang were the most cited and co-cited author.Countries,research institutions and authors in different regions cooperate closely.The hot topics included osteoporosis,differentiation,expression,in vitro,cell,osteogenesis and osteogenesis were the research frontiers in recent years.Conclusion This study conducted a bibliometric visualization analysis on the research status,research hotspots and development trend of natural products in osteoporosis for the first time.In addition,this paper also puts forward suggestions and prospects for the future development of this field,which will help researchers to open up new directions for future research in this field.
