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Physical Network Approach Applied to Wind Turbine Modeling with Simscape Language 被引量:1
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作者 Elhaini Jamila Saka Abdelmjid 《Open Journal of Modelling and Simulation》 2014年第2期77-89,共13页
Model-Based Design is an efficient and cost-effective way to develop controls, signal processing, image processing, communications, mechatronics, and other embedded systems. Rather than re-lying on physical prototypes... Model-Based Design is an efficient and cost-effective way to develop controls, signal processing, image processing, communications, mechatronics, and other embedded systems. Rather than re-lying on physical prototypes and textual specifications, Model-Based Design uses a system model as an executable specification throughout development. It supports system- and component-level design and simulation, automatic code generation, and continuous test and verification. This paper is focused firstly on the so-called model-based design and aims at presenting an up-to-date state of the art in this important field. Secondly, it develops a model based design for wind energy systems. Mathematical formulations and numerical implementations for different components of wind energy systems are highlighted with Simscape language. Finally, results are derived from simulations. 展开更多
关键词 MATHEMATICAL Modeling MODEL-BASED Design Simscape PHYSICAL network approach WIND Energy Systems
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A Neural Network Approach for Designing 2-D FIR Filters with Arbitrary Magnitude Responses
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作者 Xiaohua Wang Yigang He 《通讯和计算机(中英文版)》 2006年第3期66-71,共6页
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A neural network approach based on more input neurons to predict nuclear mass 被引量:1
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作者 Tian-Liang Zhao Hong-Fei Zhang 《Chinese Physics C》 SCIE CAS CSCD 2022年第4期123-130,共8页
The study of nuclear mass is very important,and the neural network(NN)approach can be used to improve the prediction of nuclear mass for various models.Considering the number of valence nucleons of protons and neutron... The study of nuclear mass is very important,and the neural network(NN)approach can be used to improve the prediction of nuclear mass for various models.Considering the number of valence nucleons of protons and neutrons separately in the input quantity of the NN model,the root-mean-square deviation of binding energy between data from AME2016 and liquid drop model calculations for 2314 nuclei was reduced from 2.385 MeV to 0.203 MeV.In addition,some defects in the Weizsacker-Skyrme(WS)-type model were repaired,which well reproduced the two-neutron separation energy of the nucleus synthesized recently by RIKEN RI Beam Factory[Phys.Rev.Lett.125,(2020)122501].The masses of some of the new nuclei appearing in the latest atomic mass evaluation(AME2020)are also well reproduced.However,the results of neural network methods for predicting the description of regions far from known atomic nuclei need to be further improved.This study shows that such a statistical model can be a tool for systematic searching of nuclei beyond existing experimental data. 展开更多
关键词 neural network approach liquid-drop model binding energy
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Magnetic moment predictions of odd-A nuclei with the Bayesian neural network approach 被引量:1
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作者 Zilong Yuan Dachuan Tian +1 位作者 Jian Li Zhongming Niu 《Chinese Physics C》 SCIE CAS CSCD 2021年第12期147-154,共8页
The Bayesian neural network approach has been employed to improve the nuclear magnetic moment predictions of odd-A nuclei.The Schmidt magnetic moment obtained from the extreme single-particle shell model makes large r... The Bayesian neural network approach has been employed to improve the nuclear magnetic moment predictions of odd-A nuclei.The Schmidt magnetic moment obtained from the extreme single-particle shell model makes large root-mean-square(rms)deviations from data,i.e.,0.949μN and 1.272μN for odd-neutron nuclei and odd-proton nuclei,respectively.By including the dependence of the nuclear spin and Schmidt magnetic moment,the machine-learning approach precisely describes the magnetic moments of odd-A uclei with rms deviations of 0.036μN for odd-neutron nuclei and 0.061μN for odd-proton nuclei.Furthermore,the evolution of magnetic moments along isotopic chains,including the staggering and sudden jump trend,which are difficult to describe using nuclear models,have been well reproduced by the Bayesian neural network(BNN)approach.The magnetic moments of doubly closed-shell±1 nuclei,for example,isoscalar and isovector magnetic moments,have been well studied and compared with the corresponding non-relativistic and relativistic calculations. 展开更多
关键词 magnetic moment odd-A nuclei Bayesian neural network approach
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Evolution, resilience and causes of global petroleum gas trade networks: 1995-2020 被引量:1
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作者 Na Li Yi-Ran Song +1 位作者 Ying Wang Chun-Bao Ge 《Petroleum Science》 SCIE EI CAS CSCD 2024年第5期3656-3674,共19页
Based on the HS 4-digit code trade data in UNCOMTRADE from 1995 to 2020, this paper analyzes the characteristics of the evolution of the global PG trade network using the complex network approach and analyzes the chan... Based on the HS 4-digit code trade data in UNCOMTRADE from 1995 to 2020, this paper analyzes the characteristics of the evolution of the global PG trade network using the complex network approach and analyzes the changes in its resilience at the overall and country levels, respectively. The results illustrated that:(1) The scale of the global PG trade network tends to expand, and the connection is gradually tightened, experiencing a change from a “supply-oriented” to a “supply-and-demand” pattern, in which the U.S., Russia, Qatar, and Australia have gradually replaced Canada, Japan, and Russia to become the core trade status, while OPEC countries such as Qatar, Algeria, and Kuwait mainly rely on PG exports to occupy the core of the global supply, and the trade status of other countries has been dynamically alternating and evolving.(2) The resilience of the global PG trade network is lower than that of the random network and decreases non-linearly with more disrupted countries. Moreover, the impact of the U.S. is more significant than the rest of countries. Simulations using the exponential random graph model(ERGM) model revealed that national GDP, institutional quality, common border and RTA network are the determinants of PG trade network formation, and the positive impact of the four factors not only varies significantly across regions and stages, but also increases with national network status. 展开更多
关键词 Petroleum gas Complex network approach network resilience Exponential random graph model
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Universal Electrochemical/Chemical Simulator Based on an Exponentially Expanding Grid Network Approach
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作者 邓兆祥 林祥钦 童中华 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2004年第7期719-726,共8页
A universal simulator capable of simulating virtually any user-defined electrochemical/chemical problems in one-dimensional diffusion geometry was developed based on an exponentially expanding grid modification of the... A universal simulator capable of simulating virtually any user-defined electrochemical/chemical problems in one-dimensional diffusion geometry was developed based on an exponentially expanding grid modification of the existing network approach. Some generalized reaction-diffusion governing equations of an arbitrary electrochemical/chemical process were derived, and program controlled automatic generation of the corresponding PSPICE netlist file was realized. On the basis of the above techniques, a universal simulator package was realized, which is capable of dealing with arbitrarily complex electrochemical/chemical problems with one-dimensional diffusion geometry such as planar diffusion, spherical diffusion, cylindrical diffusion and rotational disk diffusion-convection processes. The building of such a simulator is easy and thus it would be very convenient to have it updated for simulations of newly raised electrochemical problems. 展开更多
关键词 electrochemical simulator electrode process network approach exponentially expanding grid
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Research on a Neural Network Approach Based Diagnosis Expert System of Crack Control in Massive Concrete
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作者 HAN Liu-xin 1, WANG Huan-chen 1,\ ZHANG Xian-hui 2 1.Institute of Systems Engineering, Shanghai Jiaotong University, Shanghai 200052, China 2.Shanghai Yongye Enterprise (Group) Co., Ltd,200021 《Journal of Systems Science and Systems Engineering》 SCIE EI CSCD 2001年第3期359-365,共7页
A detailed study of the capabilities of artificial neural networks to diagnoses cracks in massive concrete structures is presented. This paper includes the components of the expert system such as design thought, basic... A detailed study of the capabilities of artificial neural networks to diagnoses cracks in massive concrete structures is presented. This paper includes the components of the expert system such as design thought, basic structure, building of knowledge base and the implementation of neural network applied model. The realizing method of neural network based clustering algorithm in the knowledge base and self study is analyzed emphatically and stimulated by means of the computer. From the above study, some important conclusions have been drawn and some new viewpoints have been suggested. 展开更多
关键词 neural network approach expert system crack control
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Exponentially Expanded Grid Network Approach (EEGNA): An Efficient Way for the Simulation of Stiff Electrochemical Problems
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作者 邓兆祥 林祥钦 童中华 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2003年第9期1137-1145,共9页
The exponentially expanded space grid was incorporated into the network approach to overcome the problem of low simulation efficiency during the simulations of electrochemical problems with stiff kinetics or wide disp... The exponentially expanded space grid was incorporated into the network approach to overcome the problem of low simulation efficiency during the simulations of electrochemical problems with stiff kinetics or wide dispersion of diffusion coefficients, resulting in an effective electrochemical simulation method: exponentially expanded grid network approach (EEGNA). The stability and accuracy of the EEGNA for the simulation of various electrode processes coupled with different types of homogeneous reactions were investigated. 展开更多
关键词 electrochemical simulation exponentially expanded grid network approach stiff problem
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Artificial Neural Network(ANN)Approach for Predicting Concrete Compressive Strength by SonReb
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作者 Mario Bonagura Lucio Nobile 《Structural Durability & Health Monitoring》 EI 2021年第2期125-137,共13页
The compressive strength of concrete is one of most important mechanical parameters in the performance assessment of existing reinforced concrete structures.According to various international codes,core samples are dr... The compressive strength of concrete is one of most important mechanical parameters in the performance assessment of existing reinforced concrete structures.According to various international codes,core samples are drilled and tested to obtain the concrete compressive strengths.Non-destructive testing is an important alternative when destructive testing is not feasible without damaging the structure.The commonly used non-destructive testing(NDT)methods to estimate the in-situ values include the Rebound hammer test and the Ultrasonic Pulse Velocity test.The poor reliability of these tests due to different aspects could be partially contrasted by using both methods together,as proposed.in the SonReb method.There are three techniques that are commonly used to predict the compressive strength of concrete based on the SonReb measurements:computational modeling,artificial intelligence,and parametric multi-variable regression models.In a previous study the accuracy of the correlation formulas deduced from the last technique has been investigated in comparison with the effective compressive strengths based on destructive test results on core drilled in adjacent locations.The aim of this study is to verify the accuracy of Artificial Neural Approach comparing the estimated compressive strengths based on NDT measured parameters with the same effective compressive strengths.The comparisons show the best performance of ANN approach. 展开更多
关键词 Compressive concrete strength destructive tests non-destructive test ultrasonic pulse velocity rebound index SonReb method artificial neural network approach
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An linear matrix inequality approach to global synchronisation of non-parameter perturbations of multi-delay Hopfield neural network
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作者 邵海见 蔡国梁 汪浩祥 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第11期212-217,共6页
In this study, a successful linear matrix inequality approach is used to analyse a non-parameter perturbation of multi-delay Hopfield neural network by constructing an appropriate Lyapunov-Krasovskii functional. This ... In this study, a successful linear matrix inequality approach is used to analyse a non-parameter perturbation of multi-delay Hopfield neural network by constructing an appropriate Lyapunov-Krasovskii functional. This paper presents the comprehensive discussion of the approach and also extensive applications. 展开更多
关键词 Hopfield neural network LMI approach global synchronisation sliding mode control
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Neural Network Based Normalized Fusion Approaches for Optimized Multimodal Biometric Authentication Algorithm 被引量:2
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作者 E. Sujatha A. Chilambuchelvan 《Circuits and Systems》 2016年第8期1199-1206,共8页
A multimodal biometric system is applied to recognize individuals for authentication using neural networks. In this paper multimodal biometric algorithm is designed by integrating iris, finger vein, palm print and fac... A multimodal biometric system is applied to recognize individuals for authentication using neural networks. In this paper multimodal biometric algorithm is designed by integrating iris, finger vein, palm print and face biometric traits. Normalized score level fusion approach is applied and optimized, encoded for matching decision. It is a multilevel wavelet, phase based fusion algorithm. This robust multimodal biometric algorithm increases the security level, accuracy, reduces memory size and equal error rate and eliminates unimodal biometric algorithm vulnerabilities. 展开更多
关键词 Multimodal Biometrics Score Level Fusion approach Neural network OPTIMIZATION
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全球金融风险溢出对中国系统性金融风险的影响 被引量:2
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作者 马德功 周进为 《统计与信息论坛》 北大核心 2025年第1期50-64,共15页
为了研究外部风险输入对中国金融稳定的影响,首先利用全球股票市场的日频交易数据,采用网络关联度模型构建了全球金融风险溢出网络,并基于该网络对中国面临的外部风险输入进行了量化。然后,从传染性的视角出发,从市场、行业和机构的角... 为了研究外部风险输入对中国金融稳定的影响,首先利用全球股票市场的日频交易数据,采用网络关联度模型构建了全球金融风险溢出网络,并基于该网络对中国面临的外部风险输入进行了量化。然后,从传染性的视角出发,从市场、行业和机构的角度测度了中国系统性金融风险,并对外部风险输入和中国系统性金融风险的静态结构和演化动态进行了讨论。最后,采用分位数对分位数方法(Quantile-on-Quantile Approach)进行实证分析,研究了全球金融风险溢出对中国系统性金融风险的影响在两者不同分位点上的差异。研究发现,在极端分位点上,内外风险的共振较为剧烈,而在较为温和的分位点上,这种共振的强度较弱。基于研究结果,监管部门可提高系统性金融风险监测的实时性与有效性,以防范外部风险输入引发的国内风险的共振。 展开更多
关键词 全球金融风险溢出 系统性金融风险 金融风险共振 网络关联度模型 分位数对分位数方法
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基于Transformer网络的无人机目标航迹关联方法
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作者 张强 王淳 陈亚伟 《空天预警研究学报》 2025年第2期90-92,98,共4页
针对传统航迹关联方法在密集目标场景下存在关联错误率高、关联效率低等问题,本文提出了一种基于Transformer的航迹关联方法.该方法通过Transformer网络自动抽取关联特征,自动学习航迹关联准则,实现了对雷达航迹端到端关联.仿真结果表明... 针对传统航迹关联方法在密集目标场景下存在关联错误率高、关联效率低等问题,本文提出了一种基于Transformer的航迹关联方法.该方法通过Transformer网络自动抽取关联特征,自动学习航迹关联准则,实现了对雷达航迹端到端关联.仿真结果表明,与传统的联合概率数据关联(JPDA)方法相比,本文提出的方法具备较好的航迹关联能力.该方法为解决密集目标场景下航迹关联提供了一种解决思路. 展开更多
关键词 无人蜂群 航迹关联 Transformer网络 端到端方法
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Prediction of nuclear charge density distribution with feedback neural network 被引量:5
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作者 Tian‑Shuai Shang Jian Li Zhong‑Ming Niu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2022年第12期24-35,共12页
Nuclear charge density distribution plays an important role in both nuclear and atomic physics,for which the two-parameter Fermi(2pF)model has been widely applied as one of the most frequently used models.Currently,th... Nuclear charge density distribution plays an important role in both nuclear and atomic physics,for which the two-parameter Fermi(2pF)model has been widely applied as one of the most frequently used models.Currently,the feedforward neural network has been employed to study the available 2pF model parameters for 86 nuclei,and the accuracy and precision of the parameter-learning effect are improved by introducing A^(1∕3)into the input parameter of the neural network.Furthermore,the average result of multiple predictions is more reliable than the best result of a single prediction and there is no significant difference between the average result of the density and parameter values for the average charge density distribution.In addition,the 2pF parameters of 284(near)stable nuclei are predicted in this study,which provides a reference for the experiment. 展开更多
关键词 Charge density distribution Two-parameter Fermi model Feedforward neural network approach
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干旱区流域治理中的府际合作网络研究
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作者 艾比努尔·木拉提 赵丽江 《干旱区地理》 北大核心 2025年第2期357-366,共10页
随着跨域公共事务频现对于政府治理结构及其治理能力提出新的挑战,构建跨域府际合作逐渐成为流域治理等公共问题的必然选择。现有研究主要以湿润地区流域府际合作为研究对象,对干旱地区流域治理的研究较为匮乏。以新疆南疆地区喀什噶尔... 随着跨域公共事务频现对于政府治理结构及其治理能力提出新的挑战,构建跨域府际合作逐渐成为流域治理等公共问题的必然选择。现有研究主要以湿润地区流域府际合作为研究对象,对干旱地区流域治理的研究较为匮乏。以新疆南疆地区喀什噶尔河流域治理中的府际合作网络为研究对象,运用社会网络分析方法,对流域2018—2022年5 a的阶段网络和整体网络进行研究,以廓清喀什噶尔河流域府际合作网络的演进逻辑、整体性特征和府际合作网络结构的底层逻辑。结果表明:(1)喀什噶尔河流域治理已形成相对稳定的多主体府际合作网络。流域治理逐渐呈现多元协同的治理趋势,涉水部门间的合作不断加深,逐渐将生态环境局等相关部门纳入府际合作框架之中。(2)喀什噶尔河流域治理呈现“核心-外围”式府际合作网络结构。流域治理仍以流域管理机构和水利部门为核心主体,通过横向辐射,带动多部门协同行动。(3)纵向权力形塑喀什噶尔河流域府际合作结构。促进流域地方政府突破制度惰性和部门割裂,推动跨部门合作的有效执行。 展开更多
关键词 干旱地区 流域治理 府际合作网络 社会网络方法
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Active Network研究综述 被引量:1
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作者 夏正友 钟亦平 张世永 《小型微型计算机系统》 CSCD 北大核心 2003年第10期1821-1824,共4页
介绍了两种实现 Active Network方法 ,描述 Active Network结构与组成、Active Network封装协议和 ActiveNetwork编程模型 .讨论国内外对 Active Network的研究成果和进展 .在该文最后对 Active network研究作了总结 。
关键词 Active-network 离散方法 集成方法 综述 封装协议 编程模型
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项目网络结构多尺度研究方法——以PPP社会资本项目网络的演化研究为例
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作者 冯晓威 曹吉鸣 +1 位作者 刘亮 付立欣 《管理评论》 北大核心 2025年第1期189-202,共14页
项目网络主体交互过程的动态性、交互关系的多样性使得项目网络结构呈现出复杂性系统特征。本文运用复杂网络的多尺度理论,构建项目网络从宏观到中观再到微观的多尺度分析框架,并且对PPP项目网络进行实证研究。研究发现,在全局结构层,PP... 项目网络主体交互过程的动态性、交互关系的多样性使得项目网络结构呈现出复杂性系统特征。本文运用复杂网络的多尺度理论,构建项目网络从宏观到中观再到微观的多尺度分析框架,并且对PPP项目网络进行实证研究。研究发现,在全局结构层,PPP项目网络呈现出自组织特征,项目网络中存在项目合作和战略合作两种组织合作机制。在社团聚类层,优先依附效应致使超级企业在项目网络中拥有愈来愈强的合作关系,并连同地理邻近效应共同塑造了聚类网络结构。在微观结构层,模体构成了组织之间合同治理和非合同治理的基础,且嵌入性机制揭示了PPP组织在微观层面的合作轨迹。此外,不同付费机制下,PPP社会资本组织承担的风险越高,其在宏观层面的强强联合特征、中观层面的聚类特征和微观结构中模体构成的比例就越显著。本研究的创新点在于揭示了PPP项目网络在三个层次上的合作机制,分析了时间和多尺度两个维度的演化特征,并考虑不同付费机制下PPP组织的多尺度合作特征差异。本研究为政府分析PPP项目网络提供了多尺度框架,从而有助于理解PPP组织合作行为,并且为社会资本组织提供了行业合作全景图,同时为项目网络结构的研究提供了新视角。 展开更多
关键词 项目网络 多尺度 PPP 模体 组织合作机制
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基于神经网络的硬化水泥浆体等效强度预测
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作者 宋敏 杨予舒 +1 位作者 祝华杰 王志勇 《高压物理学报》 北大核心 2025年第8期78-88,共11页
为实现材料性能优化并保障工程结构安全,需要研究具有复杂结构的水泥水化模型的力学性能。为此,考察了水灰比及各相体积分数对水泥浆体等效力学性能的影响,提出了一种基于数据驱动的模型,用于预测水化水泥结构的力学性能。通过HYMOSTRUC... 为实现材料性能优化并保障工程结构安全,需要研究具有复杂结构的水泥水化模型的力学性能。为此,考察了水灰比及各相体积分数对水泥浆体等效力学性能的影响,提出了一种基于数据驱动的模型,用于预测水化水泥结构的力学性能。通过HYMOSTRUC 3D软件生成波特兰硬化水泥浆体三维结构切片,基于Python编写的批处理程序,将切片批量转换为ABAQUS模型。通过拉伸仿真模拟,得到结构的等效弹性性能和等效强度,运用数据驱动方法建立反向传播预测模型。模型的超参数优化采用K折交叉验证方法,以提高模型的泛化能力。最终训练得到的神经网络模型能够准确预测水泥水化结构的力学性能,显著降低传统分析方法在材料微观尺度研究中的复杂性。研究结果为水泥基材料的性能预测提供了一种高效且可靠的解决方案。 展开更多
关键词 硬化水泥浆体 有限元方法 神经网络 数据驱动方法 单轴拉伸
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网状Meta分析原理与主流软件包介绍
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作者 郑卿勇 李腾飞 +9 位作者 许建国 周泳佳 高亚 刘明 徐彩花 崔雅婷 马智超 袁开森 尚轶 田金徽 《中国循证医学杂志》 北大核心 2025年第6期715-723,共9页
系统评价与Meta分析已成为整合多源研究数据、提升证据质量的核心方法。传统Meta分析在处理多种治疗选项时显示出局限性,而网状Meta分析(NMA)通过构建涵盖多种治疗选项的证据网络,允许同时比较多个治疗方案的直接与间接证据,从而提供更... 系统评价与Meta分析已成为整合多源研究数据、提升证据质量的核心方法。传统Meta分析在处理多种治疗选项时显示出局限性,而网状Meta分析(NMA)通过构建涵盖多种治疗选项的证据网络,允许同时比较多个治疗方案的直接与间接证据,从而提供更全面、精确的临床决策支持。本文全面回顾了NMA的统计学原理、三个基本假设及其统计推断框架,并对比分析了目前主流的NMA软件与软件包,如R(gemtc、netmeta、rjags、pcnetmeta等)、Stata(mvmeta、network)、WinBUGS、SAS、ADDIS及各类在线应用等,指出其优缺点及适用场景,为研究者在各种临床研究和政策制定中提供一个科学、统一的指导框架。 展开更多
关键词 网状Meta分析 原理 频率论法 贝叶斯法 软件包
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数据与知识联合驱动的舰船目标细粒度分类
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作者 郭嘉胜 刘俊 +5 位作者 何兰 姜盼 薛安克 谷雨 韩利 张杰 《光电工程》 北大核心 2025年第6期35-48,共14页
在当前舰船细粒度分类任务中,仅依赖单一图像数据的方法,只能通过提取目标的图像特征进行分类,难以捕捉舰船本体与其部件间的复杂关系,致使识别精度受限和泛化性差。提出一种数据与知识联合驱动的舰船细粒度分类方法—DKSCN,首先利用目... 在当前舰船细粒度分类任务中,仅依赖单一图像数据的方法,只能通过提取目标的图像特征进行分类,难以捕捉舰船本体与其部件间的复杂关系,致使识别精度受限和泛化性差。提出一种数据与知识联合驱动的舰船细粒度分类方法—DKSCN,首先利用目标检测网络对舰船主体及其关键部位进行检测,通过设计图卷积网络并结合专家知识建立高级语义知识图结构,来捕捉舰船主体与其关键部位间的关系,在分类的过程中融入领域知识来合理化驱动数据。在自建数据集上的对比实验结果表明,所提方法在改善单一数据驱动模型局限性的同时提高分类精度。 展开更多
关键词 舰船识别 图卷积神经网络 数据知识联合驱动 细粒度分类
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