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Traffic Flow Prediction with Heterogeneous Spatiotemporal Data Based on a Hybrid Deep Learning Model Using Attention-Mechanism
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作者 Jing-Doo Wang Chayadi Oktomy Noto Susanto 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第8期1711-1728,共18页
A significant obstacle in intelligent transportation systems(ITS)is the capacity to predict traffic flow.Recent advancements in deep neural networks have enabled the development of models to represent traffic flow acc... A significant obstacle in intelligent transportation systems(ITS)is the capacity to predict traffic flow.Recent advancements in deep neural networks have enabled the development of models to represent traffic flow accurately.However,accurately predicting traffic flow at the individual road level is extremely difficult due to the complex interplay of spatial and temporal factors.This paper proposes a technique for predicting short-term traffic flow data using an architecture that utilizes convolutional bidirectional long short-term memory(Conv-BiLSTM)with attention mechanisms.Prior studies neglected to include data pertaining to factors such as holidays,weather conditions,and vehicle types,which are interconnected and significantly impact the accuracy of forecast outcomes.In addition,this research incorporates recurring monthly periodic pattern data that significantly enhances the accuracy of forecast outcomes.The experimental findings demonstrate a performance improvement of 21.68%when incorporating the vehicle type feature. 展开更多
关键词 Traffic flow prediction sptiotemporal data heterogeneous data Conv-BiLSTM data-CENTRIC intra-data
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Multi-source heterogeneous data access management framework and key technologies for electric power Internet of Things
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作者 Pengtian Guo Kai Xiao +1 位作者 Xiaohui Wang Daoxing Li 《Global Energy Interconnection》 EI CSCD 2024年第1期94-105,共12页
The power Internet of Things(IoT)is a significant trend in technology and a requirement for national strategic development.With the deepening digital transformation of the power grid,China’s power system has initiall... The power Internet of Things(IoT)is a significant trend in technology and a requirement for national strategic development.With the deepening digital transformation of the power grid,China’s power system has initially built a power IoT architecture comprising a perception,network,and platform application layer.However,owing to the structural complexity of the power system,the construction of the power IoT continues to face problems such as complex access management of massive heterogeneous equipment,diverse IoT protocol access methods,high concurrency of network communications,and weak data security protection.To address these issues,this study optimizes the existing architecture of the power IoT and designs an integrated management framework for the access of multi-source heterogeneous data in the power IoT,comprising cloud,pipe,edge,and terminal parts.It further reviews and analyzes the key technologies involved in the power IoT,such as the unified management of the physical model,high concurrent access,multi-protocol access,multi-source heterogeneous data storage management,and data security control,to provide a more flexible,efficient,secure,and easy-to-use solution for multi-source heterogeneous data access in the power IoT. 展开更多
关键词 Power Internet of Things Object model High concurrency access Zero trust mechanism Multi-source heterogeneous data
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Blockchain-Enabled Cybersecurity Provision for Scalable Heterogeneous Network:A Comprehensive Survey
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作者 Md.Shohidul Islam Md.Arafatur Rahman +3 位作者 Mohamed Ariff Bin Ameedeen Husnul Ajra Zahian Binti Ismail Jasni Mohamad Zain 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第1期43-123,共81页
Blockchain-enabled cybersecurity system to ensure and strengthen decentralized digital transaction is gradually gaining popularity in the digital era for various areas like finance,transportation,healthcare,education,... Blockchain-enabled cybersecurity system to ensure and strengthen decentralized digital transaction is gradually gaining popularity in the digital era for various areas like finance,transportation,healthcare,education,and supply chain management.Blockchain interactions in the heterogeneous network have fascinated more attention due to the authentication of their digital application exchanges.However,the exponential development of storage space capabilities across the blockchain-based heterogeneous network has become an important issue in preventing blockchain distribution and the extension of blockchain nodes.There is the biggest challenge of data integrity and scalability,including significant computing complexity and inapplicable latency on regional network diversity,operating system diversity,bandwidth diversity,node diversity,etc.,for decision-making of data transactions across blockchain-based heterogeneous networks.Data security and privacy have also become the main concerns across the heterogeneous network to build smart IoT ecosystems.To address these issues,today’s researchers have explored the potential solutions of the capability of heterogeneous network devices to perform data transactions where the system stimulates their integration reliably and securely with blockchain.The key goal of this paper is to conduct a state-of-the-art and comprehensive survey on cybersecurity enhancement using blockchain in the heterogeneous network.This paper proposes a full-fledged taxonomy to identify the main obstacles,research gaps,future research directions,effective solutions,andmost relevant blockchain-enabled cybersecurity systems.In addition,Blockchain based heterogeneous network framework with cybersecurity is proposed in this paper tomeet the goal of maintaining optimal performance data transactions among organizations.Overall,this paper provides an in-depth description based on the critical analysis to overcome the existing work gaps for future research where it presents a potential cybersecurity design with key requirements of blockchain across a heterogeneous network. 展开更多
关键词 Blockchain CYBERSECURITY data transaction diversity heterogeneous
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Traffic Flow Prediction with Heterogenous Data Using a Hybrid CNN-LSTM Model 被引量:1
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作者 Jing-Doo Wang Chayadi Oktomy Noto Susanto 《Computers, Materials & Continua》 SCIE EI 2023年第9期3097-3112,共16页
Predicting traffic flow is a crucial component of an intelligent transportation system.Precisely monitoring and predicting traffic flow remains a challenging endeavor.However,existingmethods for predicting traffic flo... Predicting traffic flow is a crucial component of an intelligent transportation system.Precisely monitoring and predicting traffic flow remains a challenging endeavor.However,existingmethods for predicting traffic flow do not incorporate various external factors or consider the spatiotemporal correlation between spatially adjacent nodes,resulting in the loss of essential information and lower forecast performance.On the other hand,the availability of spatiotemporal data is limited.This research offers alternative spatiotemporal data with three specific features as input,vehicle type(5 types),holidays(3 types),and weather(10 conditions).In this study,the proposed model combines the advantages of the capability of convolutional(CNN)layers to extract valuable information and learn the internal representation of time-series data that can be interpreted as an image,as well as the efficiency of long short-term memory(LSTM)layers for identifying short-term and long-term dependencies.Our approach may utilize the heterogeneous spatiotemporal correlation features of the traffic flowdataset to deliver better performance traffic flow prediction than existing deep learning models.The research findings show that adding spatiotemporal feature data increases the forecast’s performance;weather by 25.85%,vehicle type by 23.70%,and holiday by 14.02%. 展开更多
关键词 heterogeneous data traffic flow prediction deep learning CNN LSTM
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Comprehensive security risk factor identification for small reservoirs with heterogeneous data based on grey relational analysis model 被引量:6
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作者 Jing-chun Feng Hua-ai Huang +1 位作者 Yao Yin Ke Zhang 《Water Science and Engineering》 EI CAS CSCD 2019年第4期330-338,共9页
Identification of security risk factors for small reservoirs is the basis for implementation of early warning systems.The manner of identification of the factors for small reservoirs is of practical significance when ... Identification of security risk factors for small reservoirs is the basis for implementation of early warning systems.The manner of identification of the factors for small reservoirs is of practical significance when data are incomplete.The existing grey relational models have some disadvantages in measuring the correlation between categorical data sequences.To this end,this paper introduces a new grey relational model to analyze heterogeneous data.In this study,a set of security risk factors for small reservoirs was first constructed based on theoretical analysis,and heterogeneous data of these factors were recorded as sequences.The sequences were regarded as random variables,and the information entropy and conditional entropy between sequences were measured to analyze the relational degree between risk factors.Then,a new grey relational analysis model for heterogeneous data was constructed,and a comprehensive security risk factor identification method was developed.A case study of small reservoirs in Guangxi Zhuang Autonomous Region in China shows that the model constructed in this study is applicable to security risk factor identification for small reservoirs with heterogeneous and sparse data. 展开更多
关键词 Security risk factor identification heterogeneous data Grey relational analysis model Relational degree Information entropy Conditional entropy Small reservoir GUANGXI
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The heterogeneous influence of economic growth on environmental pollution: evidence from municipal data of China 被引量:4
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作者 Zhen Huangfu Hui Hu +3 位作者 Nan Xie Yu-Qi Zhu Hao Chen Yang Wang 《Petroleum Science》 SCIE CAS CSCD 2020年第4期1180-1193,共14页
This study aims to investigate the influence of rapid economic development on pollution at the municipal level in China.It constructs a Stochastic Impacts by Regression on Population,Affluence and Technology model(STI... This study aims to investigate the influence of rapid economic development on pollution at the municipal level in China.It constructs a Stochastic Impacts by Regression on Population,Affluence and Technology model(STIRPAT model) and uses comprehensive municipal data on industrial pollution and economic performance.The dataset contains 290 cities from2003 to 2016 as a sample for the panel data analysis.The study further separates the cities into two groups by their levels of economic development for heterogeneity analysis.It reveals that a low level of economic development would aggravate environmental pollution,and when the economy reaches a high level,this economic development will improve environmental quality.We also find that the relationships between foreign direct investment and industrial dust and sulfur dioxide(SO_2) discharge are significant,while the relationship between economic growth and effluent emission is not.The more developed subsample cities present an inverted U-shaped curve between industrial pollutant emission,GDP per capita,and foreign direct investment,while the less developed subsamples show no such relationship.Since the shape of these curves differs among regions,their turning points vary accordingly.Based on this finding,this study suggests that the governments of more developed cities should balance environmental pollution and economic development by enhancing environmental regulations and adjusting industrial structure. 展开更多
关键词 Environmental pollution Economic development China Municipal data STIRPAT model heterogenEITY
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基于自主研发ACU&MOX-DATA平台探索腧穴功效特点研究
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作者 李思慧 刘书庆 +8 位作者 唐强 张瑞斌 陈伟 洪浩 朱冰梅 蓝勋 王勇 余曙光 吴巧凤 《中国中医药信息杂志》 CAS CSCD 2024年第2期64-69,共6页
目的基于ACU&MOX-DATA平台,初步明确不同腧穴、不同靶器官及不同刺灸法对腧穴功效的影响,并可视化展示相关结果是否存在腧穴功效“特性”“共性”的特点。方法以原创组学数据和公共组学数据整合后获得的多源异构数据作为数据源,经... 目的基于ACU&MOX-DATA平台,初步明确不同腧穴、不同靶器官及不同刺灸法对腧穴功效的影响,并可视化展示相关结果是否存在腧穴功效“特性”“共性”的特点。方法以原创组学数据和公共组学数据整合后获得的多源异构数据作为数据源,经标准化处理后,利用ACU&MOX-DATA平台中Batch Search、Stimulation Mode等模块对不同腧穴、不同靶器官、不同刺灸法的数据进行差异基因分析、疾病病理网络分析和富集分析。结果在同一疾病状态、同一干预措施下,不同腧穴间存在效应差异;在同一疾病状态、同一腧穴及干预措施下,不同靶器官产生的应答不完全一致;在同一疾病状态、同一腧穴下,不同干预措施间存在效应差异。结论基于ACU&MOX-DATA平台,初步明确腧穴、靶器官、刺灸法是影响腧穴功效的关键因素,上述结果间存在腧穴功效的特异性或共性调节特点。将ACU&MOX-DATA平台应用于针灸学领域关键科学问题的分析和可视化解读,可为深化腧穴认知、指导临床选穴、提高针灸临床疗效等提供参考。 展开更多
关键词 腧穴功效 针灸干预方式 靶器官响应 多组学数据 异源数据分析
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A Spatio-Temporal Heterogeneity Data Accuracy Detection Method Fused by GCN and TCN
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作者 Tao Liu Kejia Zhang +4 位作者 Jingsong Yin Yan Zhang Zihao Mu Chunsheng Li Yanan Hu 《Computer Systems Science & Engineering》 SCIE EI 2023年第11期2563-2582,共20页
Spatio-temporal heterogeneous data is the database for decisionmaking in many fields,and checking its accuracy can provide data support for making decisions.Due to the randomness,complexity,global and local correlatio... Spatio-temporal heterogeneous data is the database for decisionmaking in many fields,and checking its accuracy can provide data support for making decisions.Due to the randomness,complexity,global and local correlation of spatiotemporal heterogeneous data in the temporal and spatial dimensions,traditional detection methods can not guarantee both detection speed and accuracy.Therefore,this article proposes a method for detecting the accuracy of spatiotemporal heterogeneous data by fusing graph convolution and temporal convolution networks.Firstly,the geographic weighting function is introduced and improved to quantify the degree of association between nodes and calculate the weighted adjacency value to simplify the complex topology.Secondly,design spatiotemporal convolutional units based on graph convolutional neural networks and temporal convolutional networks to improve detection speed and accuracy.Finally,the proposed method is compared with three methods,ARIMA,T-GCN,and STGCN,in real scenarios to verify its effectiveness in terms of detection speed,detection accuracy and stability.The experimental results show that the RMSE,MAE,and MAPE of this method are the smallest in the cases of simple connectivity and complex connectivity degree,which are 13.82/12.08,2.77/2.41,and 16.70/14.73,respectively.Also,it detects the shortest time of 672.31/887.36,respectively.In addition,the evaluation results are the same under different time periods of processing and complex topology environment,which indicates that the detection accuracy of this method is the highest and has good research value and application prospects. 展开更多
关键词 Spatiotemporal heterogeneity data data accuracy complex topology structure graph convolutional networks temporal convolutional networks
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Construction of Mediators for Heterogeneous Data Source Integration Systems
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作者 高明 宋瀚涛 《Journal of Beijing Institute of Technology》 EI CAS 2003年第1期33-36,共4页
To construct mediators for data integration systems that integrate structured and semi-structured data, and to facilitate the reformulation and decomposition of the query, the presented system uses the XML processing ... To construct mediators for data integration systems that integrate structured and semi-structured data, and to facilitate the reformulation and decomposition of the query, the presented system uses the XML processing language (XPL) for the mediator. With XPL, it is easy to construct mediators for data integration based on XML, and it can accelerate the work in the mediator. 展开更多
关键词 heterogeneous data sources data integration MEDIATOR data model VIEW
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The influence of heterogeneous environmental regulation on the green development of the mining industry: empirical analysis based on the system GMM and dynamic panel data model
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作者 Wei Gao Jinghua Cheng Jun Zhang 《Chinese Journal of Population,Resources and Environment》 2019年第2期154-175,共22页
The intensity of environmental regulation (ERI) affects the short-term effect of the level of green mining (GML),and which structure determines the long-term mechanism.Based on the panel data from 2001 to 2015,with th... The intensity of environmental regulation (ERI) affects the short-term effect of the level of green mining (GML),and which structure determines the long-term mechanism.Based on the panel data from 2001 to 2015,with the dynamic panel model and system GMM estimation method were employed to test the influence of heterogeneous environmental regulation on green mining and its transmission mechanism.The results show that,there is a 'U' type nonlinear relationship between the ERI and GML.The direct effect of command-control-based (CAC) and the market incentive-based (MBI) environmental regulation on green development of mining shows the characteristics of inhibition and promotion.There is a 'U' type of indirectly moderating effect between technological innovation and the energy consumption structure on the GML.The technological innovation promotes the green development of the mining industry only after pass the inflection point of MBI,while the CAC plays a significant guiding role in upgrading of the energy consumption structure.There is an inhibition and promotion effect of MBI on the GML in the southeast coastal area,and the CAC is not significantly.Meanwhile,both of the ERI shows no positive effects in the central and western inland region. 展开更多
关键词 INTENSITY of ENVIRONMENTAL Regulation (ERI) green MINING heterogeneous effects dynamic PANEL data model
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Spatial Heterogeneity Modeling Using Machine Learning Based on a Hybrid of Random Forest and Convolutional Neural Network (CNN)
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作者 Amadou Kindy Barry Anthony Waititu Gichuhi Lawrence Nderu 《Journal of Data Analysis and Information Processing》 2024年第3期319-347,共29页
Spatial heterogeneity refers to the variation or differences in characteristics or features across different locations or areas in space. Spatial data refers to information that explicitly or indirectly belongs to a p... Spatial heterogeneity refers to the variation or differences in characteristics or features across different locations or areas in space. Spatial data refers to information that explicitly or indirectly belongs to a particular geographic region or location, also known as geo-spatial data or geographic information. Focusing on spatial heterogeneity, we present a hybrid machine learning model combining two competitive algorithms: the Random Forest Regressor and CNN. The model is fine-tuned using cross validation for hyper-parameter adjustment and performance evaluation, ensuring robustness and generalization. Our approach integrates Global Moran’s I for examining global autocorrelation, and local Moran’s I for assessing local spatial autocorrelation in the residuals. To validate our approach, we implemented the hybrid model on a real-world dataset and compared its performance with that of the traditional machine learning models. Results indicate superior performance with an R-squared of 0.90, outperforming RF 0.84 and CNN 0.74. This study contributed to a detailed understanding of spatial variations in data considering the geographical information (Longitude & Latitude) present in the dataset. Our results, also assessed using the Root Mean Squared Error (RMSE), indicated that the hybrid yielded lower errors, showing a deviation of 53.65% from the RF model and 63.24% from the CNN model. Additionally, the global Moran’s I index was observed to be 0.10. This study underscores that the hybrid was able to predict correctly the house prices both in clusters and in dispersed areas. 展开更多
关键词 Spatial heterogeneity Spatial data Feature Selection STANDARDIZATION Machine Learning Models Hybrid Models
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Consensus of heterogeneous multi-agent systems based on sampled data with a small sampling delay
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作者 王娜 吴治海 彭力 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第10期617-625,共9页
In this paper, consensus problems of heterogeneous multi-agent systems based on sampled data with a small sampling delay are considered. First, a consensus protocol based on sampled data with a small sampling delay fo... In this paper, consensus problems of heterogeneous multi-agent systems based on sampled data with a small sampling delay are considered. First, a consensus protocol based on sampled data with a small sampling delay for heterogeneous multi-agent systems is proposed. Then, the algebra graph theory, the matrix method, the stability theory of linear systems, and some other techniques are employed to derive the necessary and sufficient conditions guaranteeing heterogeneous multi-agent systems to asymptotically achieve the stationary consensus. Finally, simulations are performed to demonstrate the correctness of the theoretical results. 展开更多
关键词 heterogeneous multi-agent systems CONSENSUS SAMPLED-data small sampling delay
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A Modified Generative Adversarial Network for Fault Diagnosis in High-Speed Train Components with Imbalanced and Heterogeneous Monitoring Data
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作者 Chong Wang Jie Liu Enrico Zio 《Journal of Dynamics, Monitoring and Diagnostics》 2022年第2期84-92,共9页
Data-driven methods are widely considered for fault diagnosis in complex systems.However,in practice,the between-class imbalance due to limited faulty samples may deteriorate their classification performance.To addres... Data-driven methods are widely considered for fault diagnosis in complex systems.However,in practice,the between-class imbalance due to limited faulty samples may deteriorate their classification performance.To address this issue,synthetic minority methods for enhancing data have been proved to be effective in many applications.Generative adversarial networks(GANs),capable of automatic features extraction,can also be adopted for augmenting the faulty samples.However,the monitoring data of a complex system may include not only continuous signals but also discrete/categorical signals.Since the current GAN methods still have some challenges in handling such heterogeneous monitoring data,a Mixed Dual Discriminator GAN(noted as M-D2GAN)is proposed in this work.In order to render the expanded fault samples more aligned with the real situation and improve the accuracy and robustness of the fault diagnosis model,different types of variables are generated in different ways,including floating-point,integer,categorical,and hierarchical.For effectively considering the class imbalance problem,proper modifications are made to the GAN model,where a normal class discriminator is added.A practical case study concerning the braking system of a high-speed train is carried out to verify the effectiveness of the proposed framework.Compared to the classic GAN,the proposed framework achieves better results with respect to F-measure and G-mean metrics. 展开更多
关键词 braking system fault diagnosis generative adversarial network heterogeneous data high-speed train imbalanced data
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Research on Heterogeneous Data Sharing in Early Warning System for Grain Security
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作者 GUO Heng-chuan,ZHAO Guo-zeng Department of Computer and Information Engineering,Luoyang Institute of Science and Technolog,Luoyang 471023 《Agricultural Science & Technology》 CAS 2010年第5期174-177,共4页
The data nodes with heterogeneous database in early warning system for grain security seriously hampered the effective data collection in this system. In this article,the existing middleware technologies was analyzed,... The data nodes with heterogeneous database in early warning system for grain security seriously hampered the effective data collection in this system. In this article,the existing middleware technologies was analyzed,the problem-solution approach of heterogeneous data sharing was discussed through middleware technologies. Based on this method,and according to the characteristics of early warning system for grain security,the technology of data sharing in this system were researched and explored to solve the issues of collection of heterogeneous data sharing. 展开更多
关键词 Middle ware Early Waming System Web XML dataset
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Reservoir heterogeneity and fracture parameter determination using electrical image logs and petrophysical data(a case study, carbonate Asmari Formation, Zagros Basin, SW Iran) 被引量:10
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作者 Ghasem Aghli Reza Moussavi-Harami Ruhangiz Mohammadian 《Petroleum Science》 SCIE CAS CSCD 2020年第1期51-69,共19页
Assessment of reservoir and fracture parameters is necessary to optimize oil production,especially in heterogeneous reservoirs.Core and image logs are regarded as two of the best methods for this aim.However,due to co... Assessment of reservoir and fracture parameters is necessary to optimize oil production,especially in heterogeneous reservoirs.Core and image logs are regarded as two of the best methods for this aim.However,due to core limitations,using image log is considered as the best method.This study aims to use electrical image logs in the carbonate Asmari Formation reservoir in Zagros Basin,SW Iran,in order to evaluate natural fractures,porosity system,permeability profile and heterogeneity index and accordingly compare the results with core and well data.The results indicated that the electrical image logs are reliable for evaluating fracture and reservoir parameters,when there is no core available for a well.Based on the results from formation micro-imager(FMI)and electrical micro-imager(EMI),Asmari was recognized as a completely fractured reservoir in studied field and the reservoir parameters are mainly controlled by fractures.Furthermore,core and image logs indicated that the secondary porosity varies from 0%to 10%.The permeability indicator indicates that zones 3 and 5 have higher permeability index.Image log permeability index shows a very reasonable permeability profile after scaling against core and modular dynamics tester mobility,mud loss and production index which vary between 1 and 1000 md.In addition,no relationship was observed between core porosity and permeability,while the permeability relied heavily on fracture aperture.Therefore,fracture aperture was considered as the most important parameter for the determination of permeability.Sudden changes were also observed at zones 1-1 and 5 in the permeability trend,due to the high fracture aperture.It can be concluded that the electrical image logs(FMI and EMI)are usable for evaluating both reservoir and fracture parameters in wells with no core data in the Zagros Basin,SW Iran. 展开更多
关键词 FMI and EMI IMAGE LOGS Porosity and permeability FRACTURES Core data heterogeneity index
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Heterogeneous data-driven aerodynamic modeling based on physical feature embedding
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作者 Weiwei ZHANG Xuhao PENG +1 位作者 Jiaqing KOU Xu WANG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2024年第3期1-6,共6页
Aerodynamic surrogate modeling mostly relies only on integrated loads data obtained from simulation or experiment,while neglecting and wasting the valuable distributed physical information on the surface.To make full ... Aerodynamic surrogate modeling mostly relies only on integrated loads data obtained from simulation or experiment,while neglecting and wasting the valuable distributed physical information on the surface.To make full use of both integrated and distributed loads,a modeling paradigm,called the heterogeneous data-driven aerodynamic modeling,is presented.The essential concept is to incorporate the physical information of distributed loads as additional constraints within the end-to-end aerodynamic modeling.Towards heterogenous data,a novel and easily applicable physical feature embedding modeling framework is designed.This framework extracts lowdimensional physical features from pressure distribution and then effectively enhances the modeling of the integrated loads via feature embedding.The proposed framework can be coupled with multiple feature extraction methods,and the well-performed generalization capabilities over different airfoils are verified through a transonic case.Compared with traditional direct modeling,the proposed framework can reduce testing errors by almost 50%.Given the same prediction accuracy,it can save more than half of the training samples.Furthermore,the visualization analysis has revealed a significant correlation between the discovered low-dimensional physical features and the heterogeneous aerodynamic loads,which shows the interpretability and credibility of the superior performance offered by the proposed deep learning framework. 展开更多
关键词 Transonic flow data-driven modeling Feature embedding heterogenous data Feature visualization
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A GMM approach in coupling internal data and external summary information with heterogeneous data populations
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作者 Jun Shao Jinyi Wang Lei Wang 《Science China Mathematics》 SCIE CSCD 2024年第5期1115-1132,共18页
Because of advances in data collection and storage,statistical analysis in modern scientific research and practice now has opportunities to utilize external information such as summary statistics from similar studies.... Because of advances in data collection and storage,statistical analysis in modern scientific research and practice now has opportunities to utilize external information such as summary statistics from similar studies.A likelihood approach based on a parametric model assumption has been developed in the literature to utilize external summary information when the populations for external and main internal data are assumed to be the same.In this article,we instead consider the generalized estimation equation(GEE)approach for statistical inference,which is semiparametric or nonparametric,and show how to utilize external summary information even when internal and external data populations are not the same.Our approach is coupling the internal data and external summary information to form additional estimation equations and then applying the generalized method of moments(GMM).We show that the proposed GMM estimator is asymptotically normal and,under some conditions,is more efficient than the GEE estimator without using external summary information.Estimators of the asymptotic covariance matrix of the GMM estimators are also proposed.Simulation results are obtained to confirm our theory and quantify the improvements by utilizing external data.An example is also included for illustration. 展开更多
关键词 adjustment for heterogeneity CONSTRAINT data integration generalized method of moments summarystatistic
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A Fluctuation Test for Structural Change Detection in Heterogeneous Panel Data Models
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作者 LI Fuxiao XIAO Yanting CHEN Zhanshou 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2024年第3期1184-1208,共25页
Structural change in panel data is a widespread phenomena. This paper proposes a fluctuation test to detect a structural change at an unknown date in heterogeneous panel data models with or without common correlated e... Structural change in panel data is a widespread phenomena. This paper proposes a fluctuation test to detect a structural change at an unknown date in heterogeneous panel data models with or without common correlated effects. The asymptotic properties of the fluctuation statistics in two cases are developed under the null and local alternative hypothesis. Furthermore, the consistency of the change point estimator is proven. Monte Carlo simulation shows that the fluctuation test can control the probability of type I error in most cases, and the empirical power is high in case of small and moderate sample sizes. An application of the procedure to a real data is presented. 展开更多
关键词 Common correlated effects fuctuation test heterogeneous panel data models structural change detection
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Virtual 5G Network Embedding in a Heterogeneous and Multi-Domain Network Infrastructure 被引量:6
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作者 Cunqian Yu Weigang Hou +2 位作者 Yingying Guan Yue Zong Pengxing Guo 《China Communications》 SCIE CSCD 2016年第10期29-43,共15页
The pursuit of the higher performance mobile communications forces the emergence of the fifth generation mobile communication(5G). 5G network, integrating wireless and wired domain, can be qualified for the complex vi... The pursuit of the higher performance mobile communications forces the emergence of the fifth generation mobile communication(5G). 5G network, integrating wireless and wired domain, can be qualified for the complex virtual network work oriented to the cross-domain requirement. In this paper, we focus on the multi-domain virtual network embedding in a heterogeneous 5G network infrastructure, which facilitates the resource sharing for diverse-function demands from fixed/mobile end users. We proposed the mathematical ILP model for this problem.And based on the layered-substrate-resource auxiliary graph and an effective six-quadrant service-type-judgment method, 5G embedding demands can be classified accurately to match different user access densities. A collection of novel heuristic algorithms of virtual 5G network embedding are proposed. A great deal of numerical simulation results testified that our algorithm performed better in terms of average blocking rate, routing latency and wireless/wired resource utilization, compared with the benchmark. 展开更多
关键词 5G virtual network embedding heterogeneous and multi-domain infrastructure wireless channel capacity data center
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Inverse Construction Methods of Heterogeneous NURBS Object Based on Additive Manufacturing 被引量:1
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作者 Ting Zang Dongbin Zhu Guowang Mu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2020年第11期597-610,共14页
According to the requirement of heterogeneous object modeling in additive manufacturing(AM),the Non-Uniform Rational B-Spline(NURBS)method has been applied to the digital representation of heterogeneous object in this... According to the requirement of heterogeneous object modeling in additive manufacturing(AM),the Non-Uniform Rational B-Spline(NURBS)method has been applied to the digital representation of heterogeneous object in this paper.By putting forward the NURBS material data structure and establishing heterogeneous NURBS object model,the accurate mathematical unified representation of analytical and free heterogeneous objects have been realized.With the inverse modeling of heterogeneous NURBS objects,the geometry and material distribution can be better designed to meet the actual needs.Radical Basis Function(RBF)method based on global surface reconstruction and the tensor product surface interpolation method are combined to RBF-NURBS inverse construction method.The geometric and/or material information of regular mesh points is obtained by RBF interpolation of scattered data,and the heterogeneous NURBS surface or object model is obtained by tensor product interpolation.The examples have shown that the heterogeneous objects fitting to scattered data points can be generated effectively by the inverse construction methods in this paper and 3D CAD models for additive manufacturing can be provided. 展开更多
关键词 NURBS heterogeneous object inverse construction method RBF scattered data points
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