期刊文献+
共找到523,365篇文章
< 1 2 250 >
每页显示 20 50 100
改进Deep Q Networks的交通信号均衡调度算法
1
作者 贺道坤 《机械设计与制造》 北大核心 2025年第4期135-140,共6页
为进一步缓解城市道路高峰时段十字路口的交通拥堵现象,实现路口各道路车流均衡通过,基于改进Deep Q Networks提出了一种的交通信号均衡调度算法。提取十字路口与交通信号调度最相关的特征,分别建立单向十字路口交通信号模型和线性双向... 为进一步缓解城市道路高峰时段十字路口的交通拥堵现象,实现路口各道路车流均衡通过,基于改进Deep Q Networks提出了一种的交通信号均衡调度算法。提取十字路口与交通信号调度最相关的特征,分别建立单向十字路口交通信号模型和线性双向十字路口交通信号模型,并基于此构建交通信号调度优化模型;针对Deep Q Networks算法在交通信号调度问题应用中所存在的收敛性、过估计等不足,对Deep Q Networks进行竞争网络改进、双网络改进以及梯度更新策略改进,提出相适应的均衡调度算法。通过与经典Deep Q Networks仿真比对,验证论文算法对交通信号调度问题的适用性和优越性。基于城市道路数据,分别针对两种场景进行仿真计算,仿真结果表明该算法能够有效缩减十字路口车辆排队长度,均衡各路口车流通行量,缓解高峰出行方向的道路拥堵现象,有利于十字路口交通信号调度效益的提升。 展开更多
关键词 交通信号调度 十字路口 Deep Q networks 深度强化学习 智能交通
在线阅读 下载PDF
基于SE-Connection Pyramid Network网络的蛋白质-DNA结合位点预测 被引量:1
2
作者 张辰瑞 姜静清 +1 位作者 赵芳 宋佳智 《内蒙古民族大学学报(自然科学版)》 2025年第3期62-70,共9页
蛋白质与DNA的结合过程对于生物体内基因表达及调控至关重要,准确预测蛋白质上的DNA结合位点对于理解生命活动具有重要意义。构建一种基于SE-Connection Pyramid Network(SECP-Net)网络的蛋白质-DNA结合位点预测模型,该模型结合了金字... 蛋白质与DNA的结合过程对于生物体内基因表达及调控至关重要,准确预测蛋白质上的DNA结合位点对于理解生命活动具有重要意义。构建一种基于SE-Connection Pyramid Network(SECP-Net)网络的蛋白质-DNA结合位点预测模型,该模型结合了金字塔结构及Squeeze-and-Excitation模块,能够有效提取多尺度特征并动态调整特征通道的权重。通过对PDNA-62和PDNA-224数据集的实验验证,结果表明,SECP模型在多个评价指标上均优于传统模型,展现出其在蛋白质-DNA结合位点预测中的良好性能。 展开更多
关键词 卷积神经网络 特征提取 蛋白质序列
在线阅读 下载PDF
LATITUDES Network:提升证据合成稳健性的效度(偏倚风险)评价工具库
3
作者 廖明雨 熊益权 +7 位作者 赵芃 郭金 陈靖文 刘春容 贾玉龙 任燕 孙鑫 谭婧 《中国循证医学杂志》 北大核心 2025年第5期614-620,共7页
证据合成是对现有研究证据进行系统收集、分析和整合的过程,其结果依赖于纳入原始研究的质量,而效度评价(validity assessment,又称偏倚风险评价)则是评估这些原始研究质量的重要手段。现有效度评价工具种类繁多,但部分工具缺乏严格的... 证据合成是对现有研究证据进行系统收集、分析和整合的过程,其结果依赖于纳入原始研究的质量,而效度评价(validity assessment,又称偏倚风险评价)则是评估这些原始研究质量的重要手段。现有效度评价工具种类繁多,但部分工具缺乏严格的开发过程和评估,证据合成过程中应用不恰当的效度评价工具开展文献质量评价,可能会影响研究结论的准确性,误导临床实践。为解决这一困境,2023年9月英国Bristol大学学者牵头成立了效度评价工具一站式资源站LATITUDES Network。该网站致力于收集、整理和推广研究效度评价工具,以促进原始研究效度评价的准确性,提升证据合成的稳健性和可靠性。本文对LATITUDES Network成立背景、收录的效度评价工具,以及评价工具使用的培训资源等内容进行了详细介绍,以期为国内学者更多地了解LATITUDES Network,更好地运用恰当的效度评价工具开展文献质量评价,以及为开发效度评价工具等提供参考。 展开更多
关键词 效度评价 偏倚风险 证据合成 LATITUDES network
原文传递
Reconfiguration and Optimal Positioning of Multiple-Point Capacitors in a High-Voltage Distribution Network Using the NSGAII
4
作者 Arouna Oloulade Richard Gilles Agbokpanzo +6 位作者 Maurel Richy Aza-Gnandji Hassane Ousseyni Ibrahim Moussa Gonda Eméric Tokoudagba Juliano Sétondji François-Xavier Fifatin Adolphe Moukengue Imano 《Open Journal of Applied Sciences》 2025年第2期501-516,共16页
The distribution networks sometimes suffer from excessive losses and voltage violations in densely populated areas. The aim of the present study is to improve the performance of a distribution network by successively ... The distribution networks sometimes suffer from excessive losses and voltage violations in densely populated areas. The aim of the present study is to improve the performance of a distribution network by successively applying mono-capacitor positioning, multiple positioning and reconfiguration processes using GA-based algorithms implemented in a Matlab environment. From the diagnostic study of this network, it was observed that a minimum voltage of 0.90 pu induces a voltage deviation of 5.26%, followed by active and reactive losses of 425.08 kW and 435.09 kVAR, respectively. Single placement with the NSGAII resulted in the placement of a 3000 kVAR capacitor at node 128, which proved to be the invariably neuralgic point. Multiple placements resulted in a 21.55% reduction in losses and a 0.74% regression in voltage profile performance. After topology optimization, the loss profile improved by 65.08% and the voltage profile improved by 1.05%. Genetic algorithms are efficient and effective tools for improving the performance of distribution networks, whose degradation is often dynamic due to the natural variability of loads. 展开更多
关键词 RECONFIGURATION Capacitor Bank NSGA II Dynamic network Degradation Distribution network Reliability
在线阅读 下载PDF
Management of Congenital Disorders in a Resource-Limited Country: Organizational Model of a Specialized Working Group within a Perinatal Network
5
作者 Mame Diarra Ndiaye Lissoune Cisse +5 位作者 Daouda Ndour Yaye Joor Dieng Hélène Chami Mamadou Mour Traore Maguette Mbaye Pape Moctar Faye 《Open Journal of Obstetrics and Gynecology》 2025年第1期10-20,共11页
Objective: To evaluate the organizational model of a perinatal network and its relevance in a resource-limited country. Methodology: This was a mixed prospective qualitative and quantitative study conducted over a 2-y... Objective: To evaluate the organizational model of a perinatal network and its relevance in a resource-limited country. Methodology: This was a mixed prospective qualitative and quantitative study conducted over a 2-year period, from January 1, 2022, to December 31, 2023. This study took place in Senegal, a country with limited resources and a weakness of hyperspecialized medical technical resources. There was no policy for the management of fetal malformations. The qualitative part was carried out through overt participant observation. The human resources and the organization of the perinatal network were described. For the quantitative part, all fetuses managed during the study period were included. The studied parameters related to neonatal care and outcomes. Qualitative variables were described using dispersion parameters, and quantitative variables were described using proportions. Results: The perinatal network includes several specialists across six hospitals. Of these hospitals, only one provided emergency pediatric surgery. The network included highly specialized human resources in prenatal diagnosis, congenital heart defects, pediatric surgery, anesthesia, and other medical specialties in perinatology. Advanced ultrasound was centralized by an obstetrician. The team decided on the follow-up methods, timing, and mode of delivery. The newborn was immediately transferred to the appropriate specialty. Over the 2-year period, 201 fetuses were managed. The rate of cesarean delivery was 76.3%. Neonatal mortality was 51.4%. Discussion: Centralizing care improves the quality of prenatal diagnosis and management of congenital defects. Mortality remains high when emergency surgery is not well available. This mortality is also due to the lack of a single center offering all perinatal care and so, the transfer of newborns. The cesarean rate increases due to underlying conditions and organizational factors. Conclusion: Public policies should prioritize the centralization of care for congenital disorders to reduce the costs of disability and mortality. 展开更多
关键词 Congenital Disorders Perinatal network Resource-Limited Country Antenatal Diagnosis Care Centralization
在线阅读 下载PDF
Resource Optimization in Elastic Optical Networks Using Threshold-Based Routing and Fragmentation-Aware Spectrum Allocation
6
作者 Kamagaté Beman Hamidja Kanga Koffi +2 位作者 Coulibaly Kpinan Tiekoura Konaté Adama Michel Babri 《Open Journal of Applied Sciences》 2025年第1期168-186,共19页
This paper proposes an efficient strategy for resource utilization in Elastic Optical Networks (EONs) to minimize spectrum fragmentation and reduce connection blocking probability during Routing and Spectrum Allocatio... This paper proposes an efficient strategy for resource utilization in Elastic Optical Networks (EONs) to minimize spectrum fragmentation and reduce connection blocking probability during Routing and Spectrum Allocation (RSA). The proposed method, Dynamic Threshold-Based Routing and Spectrum Allocation with Fragmentation Awareness (DT-RSAF), integrates rerouting and spectrum defragmentation as needed. By leveraging Yen’s shortest path algorithm, DT-RSAF enhances resource utilization while ensuring improved service continuity. A dynamic threshold mechanism enables the algorithm to adapt to varying network conditions, while its fragmentation awareness effectively mitigates spectrum fragmentation. Simulation results on NSFNET and COST 239 topologies demonstrate that DT-RSAF significantly outperforms methods such as K-Shortest Path Routing and Spectrum Allocation (KSP-RSA), Load Balanced and Fragmentation-Aware (LBFA), and the Invasive Weed Optimization-based RSA (IWO-RSA). Under heavy traffic, DT-RSAF reduces the blocking probability by up to 15% and achieves lower Bandwidth Fragmentation Ratios (BFR), ranging from 74% to 75%, compared to 77% - 80% for KSP-RSA, 75% - 77% for LBFA, and approximately 76% for IWO-RSA. DT-RSAF also demonstrated reasonable computation times compared to KSP-RSA, LBFA, and IWO-RSA. On a small-sized network, its computation time was 8710 times faster than that of Integer Linear Programming (ILP) on the same network topology. Additionally, it achieved a similar execution time to LBFA and outperformed IWO-RSA in terms of efficiency. These results highlight DT-RSAF’s capability to maintain large contiguous frequency blocks, making it highly effective for accommodating high-bandwidth requests in EONs while maintaining reasonable execution times. 展开更多
关键词 Elastic Optical networks (EONs) Spectrum Fragmentation Routing and Spectrum Allocation (RSA) Connection Rerouting HEURISTIC
在线阅读 下载PDF
Aspect-Level Sentiment Analysis of Bi-Graph Convolutional Networks Based on Enhanced Syntactic Structural Information
7
作者 Junpeng Hu Yegang Li 《Journal of Computer and Communications》 2025年第1期72-89,共18页
Aspect-oriented sentiment analysis is a meticulous sentiment analysis task that aims to analyse the sentiment polarity of specific aspects. Most of the current research builds graph convolutional networks based on dep... Aspect-oriented sentiment analysis is a meticulous sentiment analysis task that aims to analyse the sentiment polarity of specific aspects. Most of the current research builds graph convolutional networks based on dependent syntactic trees, which improves the classification performance of the models to some extent. However, the technical limitations of dependent syntactic trees can introduce considerable noise into the model. Meanwhile, it is difficult for a single graph convolutional network to aggregate both semantic and syntactic structural information of nodes, which affects the final sentence classification. To cope with the above problems, this paper proposes a bi-channel graph convolutional network model. The model introduces a phrase structure tree and transforms it into a hierarchical phrase matrix. The adjacency matrix of the dependent syntactic tree and the hierarchical phrase matrix are combined as the initial matrix of the graph convolutional network to enhance the syntactic information. The semantic information feature representations of the sentences are obtained by the graph convolutional network with a multi-head attention mechanism and fused to achieve complementary learning of dual-channel features. Experimental results show that the model performs well and improves the accuracy of sentiment classification on three public benchmark datasets, namely Rest14, Lap14 and Twitter. 展开更多
关键词 Aspect-Level Sentiment Analysis Sentiment Knowledge Multi-Head Attention Mechanism Graph Convolutional networks
在线阅读 下载PDF
基于CNN-Swin Transformer Network的LPI雷达信号识别 被引量:1
8
作者 苏琮智 杨承志 +2 位作者 邴雨晨 吴宏超 邓力洪 《现代雷达》 CSCD 北大核心 2024年第3期59-65,共7页
针对在低信噪比(SNR)条件下,低截获概率雷达信号调制方式识别准确率低的问题,提出一种基于Transformer和卷积神经网络(CNN)的雷达信号识别方法。首先,引入Swin Transformer模型并在模型前端设计CNN特征提取层构建了CNN+Swin Transforme... 针对在低信噪比(SNR)条件下,低截获概率雷达信号调制方式识别准确率低的问题,提出一种基于Transformer和卷积神经网络(CNN)的雷达信号识别方法。首先,引入Swin Transformer模型并在模型前端设计CNN特征提取层构建了CNN+Swin Transformer网络(CSTN),然后利用时频分析获取雷达信号的时频特征,对图像进行预处理后输入CSTN模型进行训练,由网络的底部到顶部不断提取图像更丰富的语义信息,最后通过Softmax分类器对六类不同调制方式信号进行分类识别。仿真实验表明:在SNR为-18 dB时,该方法对六类典型雷达信号的平均识别率达到了94.26%,证明了所提方法的可行性。 展开更多
关键词 低截获概率雷达 信号调制方式识别 Swin Transformer网络 卷积神经网络 时频分析
原文传递
考虑电动汽车充电模式的配电网可开放容量提升改造策略 被引量:3
9
作者 陈鹏 刘友波 +3 位作者 袁川 唐冬来 向月 刘俊勇 《电网技术》 北大核心 2025年第1期177-186,I0068-I0075,共18页
配电网可开放容量代表着现有配电网条件下最大可接入的负荷容量,是评估配电网规划与运行效果的重要指标之一。为应对电动汽车大规模无序充电导致可开放容量大幅度下降的现象,提出一种考虑电动汽车充电模式的配电网网格改造方法,通过优... 配电网可开放容量代表着现有配电网条件下最大可接入的负荷容量,是评估配电网规划与运行效果的重要指标之一。为应对电动汽车大规模无序充电导致可开放容量大幅度下降的现象,提出一种考虑电动汽车充电模式的配电网网格改造方法,通过优化网格拓扑结构以及有限投资内线路扩容与储能投入的最佳数量、位置和类型,实现可开放容量的最优提升。首先,利用蒙特卡洛法生成电动汽车无序充电场景,并搭建基于充电时序优化的电动汽车有序充电模型;其次,搭建基于网络重构、线路扩容及储能投资协同的配电网可开放容量提升改造模型;然后,通过Benders分解算法降低模型复杂度,并调用商业求解器求解;最后,以某城市实际配电网网格为算例,验证了所提可开放容量提升改造策略的有效性。 展开更多
关键词 可开放容量 配电网改造 有序充电 线路扩容 储能 网络重构
原文传递
计及铁心非线性的变压器空间动态磁场加速计算方法 被引量:3
10
作者 司马文霞 孙佳琪 +3 位作者 杨鸣 邹德旭 彭庆军 王劲松 《电工技术学报》 北大核心 2025年第5期1559-1574,共16页
快速获得变压器空间磁场动态分布是构建变压器数字孪生体的基础之一,然而现有快速计算方法难以快速、准确地获得铁心饱和工况下的磁场分布特性。因此,该文提出了计及铁心非线性的变压器空间动态磁场加速计算方法。首先,构建变压器电磁... 快速获得变压器空间磁场动态分布是构建变压器数字孪生体的基础之一,然而现有快速计算方法难以快速、准确地获得铁心饱和工况下的磁场分布特性。因此,该文提出了计及铁心非线性的变压器空间动态磁场加速计算方法。首先,构建变压器电磁场路耦合仿真模型,对关键变量进行参数化扫描,仿真获得不同非线性工况下的大量磁场数据,构建涉及铁心非线性工况的主磁通和漏磁通数据集;其次,提出融合卷积神经网络(CNN)和长短期记忆网络(LSTM)的双分支深度学习模型,训练提取磁场数据的空间和时间特征,解决主、漏磁通差异大造成的模型训练难题;最后,利用模型获得输入电压、电流与内部空间磁场分布的非线性映射关系,实现空间动态磁场的加速计算,为变压器数字孪生体的构建提供了快速获得磁场数据的方法。 展开更多
关键词 非线性 卷积神经网络 长短期记忆网络 磁场 加速计算
在线阅读 下载PDF
Enhancing Urban Intelligence Energy Management: Innovative Load Forecasting Techniques for Electrical Networks 被引量:2
11
作者 Zeinab Farrokhi Kamran Hassanpouri Baesmat Emma E. Regentova 《Journal of Power and Energy Engineering》 2024年第11期72-88,共17页
Energy sustains the world, yet fossil fuels, a finite resource, are dwindling. This necessitates a shift towards more sustainable energy sources, such as electricity. Accurate load forecasting is crucial in today’s g... Energy sustains the world, yet fossil fuels, a finite resource, are dwindling. This necessitates a shift towards more sustainable energy sources, such as electricity. Accurate load forecasting is crucial in today’s global energy landscape, as it helps predict various aspects such as production, revenue, consumption, economic conditions, weather impacts, power system utilization, customer demand, and economic growth. For instance, an increase in electricity demand within a country often signifies a boost in industry and production, leading to economic progress and reduced unemployment. This project aims to enhance prediction accuracy through meticulous input filtering, taking into account factors like population growth, planned loads, inflation, and competitive pricing pressures from producers. Despite inherent prediction errors, efforts are made to minimize these discrepancies. This paper introduces a novel combined method for mid-term energy forecasting. To demonstrate its efficacy, real data from the past ten months, collected from subscribers of the Kerman distribution company, was used to forecast energy consumption over the next ten days. The innovative method, which integrates multiple forecasting techniques and robust filters, significantly improves forecasting precision. The following error metrics were recorded for the proposed method: MSE: 0.009, MAE: 0.083, MAPE: 0.776, RMSE: 0.095, AE: 0.013. 展开更多
关键词 Energy Prediction Forecasting Regression Neural network MTLF
在线阅读 下载PDF
基于神经网络模型的煤层气产能预测研究 被引量:1
12
作者 金毅 郑晨晖 +5 位作者 宋慧波 马家恒 杨运航 刘顺喜 张昆 倪小明 《河南理工大学学报(自然科学版)》 CAS 北大核心 2025年第1期46-56,共11页
目的煤层气产能主要受地质和工程因素影响,阐明这些因素对煤层气井产能的影响机制是实现储层精细改造和煤层气井提产的基础。方法本文以沁水盆地柿庄南区块为研究对象,综合考虑地质背景、储层物性和动态排采数据,利用神经网络算法开展... 目的煤层气产能主要受地质和工程因素影响,阐明这些因素对煤层气井产能的影响机制是实现储层精细改造和煤层气井提产的基础。方法本文以沁水盆地柿庄南区块为研究对象,综合考虑地质背景、储层物性和动态排采数据,利用神经网络算法开展煤层气产能预测。首先,利用灰色关联分析法遴选出10个地质参数作为煤层气产能预测的主控因素,在此基础上,运用模糊数学法实现研究区34口煤层气井富集区划分,最后,根据分类结果,结合实际排采数据,分别利用BP(back propagation)和LSTM(long short-term memory)神经网络算法实现煤层气井日产气量预测。结果结果表明:(1)渗透率、含气饱和度和储层压力梯度等10个参数是影响研究区煤层气产气性能的关键因素;(2)利用模糊数学评价方法评价煤层气的富集,可将研究区34口井产气效果划分为有利区、较有利区和不利区;(3)依托LSTM算法建立了煤储层日产气量预测模型,预测误差值为4.06%~14.79%,平均误差值为11.09%,预测精度明显高于BP神经网络模型,结论根据LSTM算法建立的煤储层日产气量预测模型稳定性好且预测精度高,可作为煤储层产能长程预测的一种有效手段,进而为煤层气开发工艺布施与排采方案制定提供科学依据。 展开更多
关键词 LSTM神经网络 BP神经网络 灰色关联分析 产能预测
在线阅读 下载PDF
Brain Functional Network Changes in Patients with Poststroke Cognitive Impairment Following Acupuncture Therapy 被引量:1
13
作者 Ran Wang Nian Liu +4 位作者 Hao Xu Peng Zhang Xiaohua Huang Lin Yang Xiaoming Zhang 《Health》 2024年第9期856-871,共16页
Background: The mechanisms by which acupuncture affects poststroke cognitive impairment (PSCI) remain unclear. Objective: To investigate brain functional network (BFN) changes in patients with PSCI after acupuncture t... Background: The mechanisms by which acupuncture affects poststroke cognitive impairment (PSCI) remain unclear. Objective: To investigate brain functional network (BFN) changes in patients with PSCI after acupuncture therapy. Methods: Twenty-two PSCI patients who underwent acupuncture therapy in our hospital were enrolled as research subjects. Another 14 people matched for age, sex, and education level were included in the normal control (HC) group. All the subjects underwent resting-state functional magnetic resonance imaging (rs-fMRI) scans;the PSCI patients underwent one scan before acupuncture therapy and another after. The network metric difference between PSCI patients and HCs was analyzed via the independent-sample t test, whereas the paired-sample t test was employed to analyze the network metric changes in PSCI patients before vs. after treatment. Results: Small-world network attributes were observed in both groups for sparsities between 0.1 and 0.28. Compared with the HC group, the PSCI group presented significantly lower values for the global topological properties (γ, Cp, and Eloc) of the brain;significantly greater values for the nodal attributes of betweenness centrality in the CUN. L and the HES. R, degree centrality in the SFGdor. L, PCG. L, IPL. L, and HES. R, and nodal local efficiency in the ORBsup. R, ORBsupmed. R, DCG. L, SMG. R, and TPOsup. L;and decreased degree centrality in the MFG. R, IFGoperc. R, and SOG. R. After treatment, PSCI patients presented increased degree centrality in the LING.L, LING.R, and IOG. L and nodal local efficiency in PHG. L, IOG. R, FFG. L, and the HES. L, and decreased betweenness centrality in the PCG. L and CUN. L, degree centrality in the ORBsupmed. R, and nodal local efficiency in ANG. R. Conclusion: Cognitive decline in PSCI patients may be related to BFN disorders;acupuncture therapy may modulate the topological properties of the BFNs of PSCI patients. 展开更多
关键词 Cognitive Decline Poststroke Cognitive Impairment Functional Magnetic Resonance Imaging Brain Functional network Graph Theoretical Analysis
暂未订购
全球生产网络中领先企业策略合作伙伴对区域产业发展的影响——以郑州富士康为例 被引量:4
14
作者 赵建吉 王艳华 苗长虹 《经济地理》 北大核心 2025年第2期1-11,共11页
全球生产网络与区域发展是国际经济地理学研究的热点和前沿,而对于全球生产网络中领先企业策略合作伙伴主导的地方企业网络的研究更应引起重视。文章基于郑州富士康的典型案例,通过构建“权力关系—制度安排—产业发展”的分析框架,研... 全球生产网络与区域发展是国际经济地理学研究的热点和前沿,而对于全球生产网络中领先企业策略合作伙伴主导的地方企业网络的研究更应引起重视。文章基于郑州富士康的典型案例,通过构建“权力关系—制度安排—产业发展”的分析框架,研究了领先企业策略合作伙伴对区域产业发展的影响。研究发现:(1)富士康落地郑州后,发挥权力关系吸引了其原有部分供应商转移到郑州。地方政府依托富士康发展电子信息产业的优惠政策及塑造的产业发展生态,吸引了大批非苹果手机企业在郑州集聚。(2)郑州航空港经济综合实验区智能终端(手机)形成了三重企业网络,分别为富士康权力关系主导的企业网络、富士康跨界企业网络、地方政府引导形成的非苹果手机企业网络。(3)苹果手机最大生产基地和全球智能终端(手机)制造基地的形成,加快推动了承接地的产业结构调整。(4)全球生产网络中领先企业的权力关系和地方政府的制度安排深刻影响了智能终端(手机)企业集聚和企业网络的形成。研究结果刻画了全球生产网络中领先企业策略合作伙伴在后发地区的地方企业网络特征,拓展了全球生产网络中的权力关系研究视角。 展开更多
关键词 全球生产网络 战略耦合 领先企业策略合作伙伴 地方企业网络 电子信息产业 产业集聚 富士康
原文传递
Security Implications of Edge Computing in Cloud Networks 被引量:2
15
作者 Sina Ahmadi 《Journal of Computer and Communications》 2024年第2期26-46,共21页
Security issues in cloud networks and edge computing have become very common. This research focuses on analyzing such issues and developing the best solutions. A detailed literature review has been conducted in this r... Security issues in cloud networks and edge computing have become very common. This research focuses on analyzing such issues and developing the best solutions. A detailed literature review has been conducted in this regard. The findings have shown that many challenges are linked to edge computing, such as privacy concerns, security breaches, high costs, low efficiency, etc. Therefore, there is a need to implement proper security measures to overcome these issues. Using emerging trends, like machine learning, encryption, artificial intelligence, real-time monitoring, etc., can help mitigate security issues. They can also develop a secure and safe future in cloud computing. It was concluded that the security implications of edge computing can easily be covered with the help of new technologies and techniques. 展开更多
关键词 Edge Computing Cloud networks Artificial Intelligence Machine Learning Cloud Security
在线阅读 下载PDF
水网构建对汾河流域水资源系统韧性演变的影响 被引量:5
16
作者 万芳 王煜 +4 位作者 王威浩 郑小康 韩文浩 严登明 张迪 《水资源保护》 北大核心 2025年第1期19-26,共8页
为研究水网构建对汾河流域水资源系统韧性演变的影响,针对汾河流域水资源系统韧性在系统、空间、时间维度上的不断演化发展,考虑到水资源系统韧性对初始条件的敏感依赖性以及韧性的非线性和不可预测性等特征符合混沌理论的主要特征,基... 为研究水网构建对汾河流域水资源系统韧性演变的影响,针对汾河流域水资源系统韧性在系统、空间、时间维度上的不断演化发展,考虑到水资源系统韧性对初始条件的敏感依赖性以及韧性的非线性和不可预测性等特征符合混沌理论的主要特征,基于混沌理论构建了水资源系统韧性评价模型,分析了2017—2021年汾河流域水资源系统韧性时空演变特征,分别以2020年、2035年为基准年和水平年,探究了2035年有、无水网情况下,汾河流域水资源系统韧性水平的变化情况。结果表明:2017—2020年汾河流域水资源系统韧性水平波动较小,总体呈现上升趋势,且表现为西部高于东部、北部高于南部的空间分布特征,2021年水资源系统韧性水平有所下降;相较于基准年,无水网情况下2035年流域和各地区水资源系统韧性水平均有不同程度的下降;有水网情况下2035年流域水资源系统韧性水平相较于无水网情况有大幅度提升,各地区消除了低韧性水平,水网构建对流域水资源系统韧性的提升效果显著。 展开更多
关键词 水资源系统韧性 水网构建 混沌理论 复杂网络 汾河流域
在线阅读 下载PDF
黄芩苷调控TUG1/PTBP1/NLRP3分子网络抑制巨噬细胞焦亡治疗溃疡性结肠炎的机制 被引量:4
17
作者 李克亚 肖金银 +8 位作者 罗雯鹏 陆文洪 贺荔枝 潘燎 赵建政 成思宇 肖俐敏 王军文 王真权 《中草药》 北大核心 2025年第5期1667-1681,共15页
目的探讨黄芩苷调控牛磺酸上调基因1(taurine up-regulated gene 1,TUG1)/多嘧啶束结合蛋白1(polypyrimidine tract binding protein 1,PTBP1)/核苷酸结合寡聚化结构域样受体蛋白3(nucleotide-binding oligomerization domain-like rece... 目的探讨黄芩苷调控牛磺酸上调基因1(taurine up-regulated gene 1,TUG1)/多嘧啶束结合蛋白1(polypyrimidine tract binding protein 1,PTBP1)/核苷酸结合寡聚化结构域样受体蛋白3(nucleotide-binding oligomerization domain-like receptor protein 3,NLRP3)分子网络抑制巨噬细胞焦亡治疗溃疡性结肠炎(ulcerative colitis,UC)的作用机制。方法利用葡聚糖硫酸钠(dextran sulfate sodium salt,DSS)诱导构建UC小鼠模型,将小鼠随机分为对照组、模型组、美沙拉嗪(600 mg/kg)组和黄芩苷低、中、高剂量(25、50、100 mg/kg)组,连续ig给药处理7 d,观察小鼠日常活动变化,苏木素-伊红(hematoxylin eosin,HE)染色和透射电镜观察结肠组织的结构变化,生化检测血清中髓过氧化物酶(myeloperoxidase,MPO)活性。通过脂多糖(lipopolysaccharide,LPS)+三磷酸腺苷(adenosine triphosphate,ATP)诱导THP-1细胞分化构建UC体外模型,将其随机分为对照组、模型组、美沙拉嗪(100μmol/L)组、黄芩苷不同剂量组。酶联免疫吸附测定(enzyme linked immunosorbent assay,ELISA)检测血清和细胞中白细胞介素-1β(interleukin-1β,IL-1β)、IL-18表达;流式检测结肠组织和细胞中半胱氨酸天冬氨酸蛋白酶-1(cystein-asparate protease-1,Caspase-1)表达;Western blotting检测结肠组织和细胞中PTBP1、NLRP3、凋亡相关颗粒样蛋白(apoptosis-associated speck-like protein containing a CARD,ASC)、Caspase-1、GSDMD蛋白C端片段(gasdermin D-C,GSDMD-C)、GSDMD-N蛋白表达;逆转录实时定量聚合酶链式反应(reverse transcription quantitative polymerase chain reaction,RT-qPCR)检测TUGI、PTBP1、NLRP3表达。RNA pull-down和RNA结合蛋白免疫沉淀(RNA immunoprecipitation,RIP)验证TUG1与PTBP1的相互作用;挽救实验进一步验证TUG1-PTBP1在UC中调控巨噬细胞焦亡的作用。结果体内外研究表明,与模型组比较,黄芩苷能够显著降低UC小鼠的疾病活动指数(disease activity index,DAI)评分(P<0.001),抑制结肠缩短,减轻结肠病理损伤,降低IL-1β、IL-18、MPO、Caspase-1表达(P<0.01、0.001),降低结肠组织和细胞中焦亡相关指标的表达(P<0.05、0.01、0.001),其中以高剂量黄芩苷效果最为明显。此外,黄芩苷通过降低TUG1的表达,影响PTBP1与TUG1的结合,进而抑制NLRP3炎症体的活化,从而抑制巨噬细胞焦亡。结论黄芩苷能够有效缓解UC,可能与调控TUG1/PTBP1/NLRP3分子网络抑制巨噬细胞焦亡有关。 展开更多
关键词 黄芩苷 溃疡性结肠炎 巨噬细胞 焦亡 TUG1/PTBP1/NLRP3分子网络
原文传递
基于MSCNN-GRU神经网络补全测井曲线和可解释性的智能岩性识别 被引量:2
18
作者 王婷婷 王振豪 +2 位作者 赵万春 蔡萌 史晓东 《石油地球物理勘探》 北大核心 2025年第1期1-11,共11页
针对传统岩性识别方法在处理测井曲线缺失、准确性以及模型可解释性等方面的不足,提出了一种基于MSCNN-GRU神经网络补全测井曲线和Optuna超参数优化的XGBoost模型的可解释性的岩性识别方法。首先,针对测井曲线在特定层段丢失或失真的问... 针对传统岩性识别方法在处理测井曲线缺失、准确性以及模型可解释性等方面的不足,提出了一种基于MSCNN-GRU神经网络补全测井曲线和Optuna超参数优化的XGBoost模型的可解释性的岩性识别方法。首先,针对测井曲线在特定层段丢失或失真的问题,引入了基于多尺度卷积神经网络(MSCNN)与门控循环单元(GRU)神经网络相结合的曲线重构方法,为后续的岩性识别提供了准确的数据基础;其次,利用小波包自适应阈值方法对数据进行去噪和归一化处理,以减少噪声对岩性识别的影响;然后,采用Optuna框架确定XGBoost算法的超参数,建立了高效的岩性识别模型;最后,利用SHAP可解释性方法对XGBoost模型进行归因分析,揭示了不同特征对于岩性识别的贡献度,提升了模型的可解释性。结果表明,Optuna-XGBoost模型综合岩性识别准确率为79.91%,分别高于支持向量机(SVM)、朴素贝叶斯、随机森林三种神经网络模型24.89%、12.45%、6.33%。基于Optuna-XGBoost模型的SHAP可解释性的岩性识别方法具有更高的准确性和可解释性,能够更好地满足实际生产需要。 展开更多
关键词 岩性识别 多尺度卷积神经网络 门控循环单元神经网络 XGBoost 超参数优化 可解释性
在线阅读 下载PDF
社交网络圈群极化:不同类型意见领袖的异质性分析 被引量:2
19
作者 张媛媛 王鑫磊 +1 位作者 杨永清 吴江 《图书情报知识》 北大核心 2025年第2期145-155,共11页
[目的/意义]从社交网络圈群极化的角度,探索不同类型意见领袖网络圈群的异质性,为舆情治理部门针对群体极化现象采取圈群差异化治理策略提供理论参考及决策支持。[研究设计/方法]以微博平台为例,获取舆情事件数据,采用多元回归模型分析... [目的/意义]从社交网络圈群极化的角度,探索不同类型意见领袖网络圈群的异质性,为舆情治理部门针对群体极化现象采取圈群差异化治理策略提供理论参考及决策支持。[研究设计/方法]以微博平台为例,获取舆情事件数据,采用多元回归模型分析不同圈群意见领袖与圈群舆论极化、群体极化之间的关系。[结论/发现]在圈群舆论极化方面,当意见领袖为个人用户时,圈群用户与意见领袖情感态度的差异程度对圈群舆论极化程度具有显著的负向影响;当意见领袖为官方机构用户时,圈群用户与意见领袖情感态度的差异程度对圈群舆论极化程度具有显著的正向影响。在圈群群体极化方面,圈群中的讨论次数对群体极化程度具有显著的负向影响,意见领袖认证类型和情感强度对这种影响具显著的调节作用,而圈群意见领袖影响力对其不具有显著的调节作用。圈群意见领袖为官方机构用户时较个人用户会增强两者间的影响关系,圈群意见领袖情感增强时会减弱两者间的影响关系。[创新/价值]引入意见领袖类型作为调节变量,探究了各类意见领袖对圈群群体极化程度的影响差异,拓展了群体极化影响机制的相关研究,提供了基于网络圈群研究群体极化的新思路。 展开更多
关键词 社交网络舆情 网络圈群 舆论极化 群体极化 意见领袖
在线阅读 下载PDF
A generative adversarial network-based unified model integrating bias correction and downscaling for global SST
20
作者 Shijin Yuan Xin Feng +3 位作者 Bin Mu Bo Qin Xin Wang Yuxuan Chen 《Atmospheric and Oceanic Science Letters》 CSCD 2024年第1期45-52,共8页
本文提出了一种基于生成对抗网络的全球海表面温度(sea surface temperature,SST)偏差订正及降尺度整合模型.该模型的生成器使用偏差订正模块将数值模式预测结果进行校正,再用可复用的共享降尺度模块将订正后的数据分辨率逐次提高.该模... 本文提出了一种基于生成对抗网络的全球海表面温度(sea surface temperature,SST)偏差订正及降尺度整合模型.该模型的生成器使用偏差订正模块将数值模式预测结果进行校正,再用可复用的共享降尺度模块将订正后的数据分辨率逐次提高.该模型的判别器可鉴别偏差订正及降尺度结果的质量,以此为标准进行对抗训练。同时,在对抗损失函数中含有物理引导的动力学惩罚项以提高模型的性能.本研究基于分辨率为1°的GFDL SPEAR模式的SST预测结果,选择遥感系统(Remote Sensing System)的观测资料作为真值,面向月尺度ENSO与IOD事件以及天尺度海洋热浪事件开展了验证试验:模型在将分辨率提高到0.0625°×0.0625°的同时将预测误差减少约90.3%,突破了观测数据分辨率的限制,且与观测结果的结构相似性高达96.46%. 展开更多
关键词 偏差订正 降尺度 海表面温度 生成对抗网络 物理引导的神经网络
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部