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PIDINet-MC:Real-Time Multi-Class Edge Detection with PiDiNet
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作者 Mingming Huang Yunfan Ye Zhiping Cai 《Computers, Materials & Continua》 2026年第2期1983-1999,共17页
As a fundamental component in computer vision,edges can be categorized into four types based on discontinuities in reflectance,illumination,surface normal,or depth.While deep CNNs have significantly advanced generic e... As a fundamental component in computer vision,edges can be categorized into four types based on discontinuities in reflectance,illumination,surface normal,or depth.While deep CNNs have significantly advanced generic edge detection,real-time multi-class semantic edge detection under resource constraints remains challenging.To address this,we propose a lightweight framework based on PiDiNet that enables fine-grained semantic edge detection.Our model simultaneously predicts background and four edge categories from full-resolution inputs,balancing accuracy and efficiency.Key contributions include:a multi-channel output structure expanding binary edge prediction to five classes,supported by a deep supervision mechanism;a dynamic class-balancing strategy combining adaptive weighting with physical priors to handle extreme class imbalance;and maintained architectural efficiency enabling real-time inference.Extensive evaluations on BSDS-RIND show our approach achieves accuracy competitive with state-of-the-art methods while operating in real time. 展开更多
关键词 multi-class edge detection REAL-TIME LIGHTWEIGHT deep supervision
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A Hybrid Deep Learning Multi-Class Classification Model for Alzheimer’s Disease Using Enhanced MRI Images
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作者 Ghadah Naif Alwakid 《Computers, Materials & Continua》 2026年第1期797-821,共25页
Alzheimer’s Disease(AD)is a progressive neurodegenerative disorder that significantly affects cognitive function,making early and accurate diagnosis essential.Traditional Deep Learning(DL)-based approaches often stru... Alzheimer’s Disease(AD)is a progressive neurodegenerative disorder that significantly affects cognitive function,making early and accurate diagnosis essential.Traditional Deep Learning(DL)-based approaches often struggle with low-contrast MRI images,class imbalance,and suboptimal feature extraction.This paper develops a Hybrid DL system that unites MobileNetV2 with adaptive classification methods to boost Alzheimer’s diagnosis by processing MRI scans.Image enhancement is done using Contrast-Limited Adaptive Histogram Equalization(CLAHE)and Enhanced Super-Resolution Generative Adversarial Networks(ESRGAN).A classification robustness enhancement system integrates class weighting techniques and a Matthews Correlation Coefficient(MCC)-based evaluation method into the design.The trained and validated model gives a 98.88%accuracy rate and 0.9614 MCC score.We also performed a 10-fold cross-validation experiment with an average accuracy of 96.52%(±1.51),a loss of 0.1671,and an MCC score of 0.9429 across folds.The proposed framework outperforms the state-of-the-art models with a 98%weighted F1-score while decreasing misdiagnosis results for every AD stage.The model demonstrates apparent separation abilities between AD progression stages according to the results of the confusion matrix analysis.These results validate the effectiveness of hybrid DL models with adaptive preprocessing for early and reliable Alzheimer’s diagnosis,contributing to improved computer-aided diagnosis(CAD)systems in clinical practice. 展开更多
关键词 Alzheimer’s disease deep learning MRI images MobileNetV2 contrast-limited adaptive histogram equalization(CLAHE) enhanced super-resolution generative adversarial networks(ESRGAN) multi-class classification
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Towards Decentralized IoT Security: Optimized Detection of Zero-Day Multi-Class Cyber-Attacks Using Deep Federated Learning
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作者 Misbah Anwer Ghufran Ahmed +3 位作者 Maha Abdelhaq Raed Alsaqour Shahid Hussain Adnan Akhunzada 《Computers, Materials & Continua》 2026年第1期744-758,共15页
The exponential growth of the Internet of Things(IoT)has introduced significant security challenges,with zero-day attacks emerging as one of the most critical and challenging threats.Traditional Machine Learning(ML)an... The exponential growth of the Internet of Things(IoT)has introduced significant security challenges,with zero-day attacks emerging as one of the most critical and challenging threats.Traditional Machine Learning(ML)and Deep Learning(DL)techniques have demonstrated promising early detection capabilities.However,their effectiveness is limited when handling the vast volumes of IoT-generated data due to scalability constraints,high computational costs,and the costly time-intensive process of data labeling.To address these challenges,this study proposes a Federated Learning(FL)framework that leverages collaborative and hybrid supervised learning to enhance cyber threat detection in IoT networks.By employing Deep Neural Networks(DNNs)and decentralized model training,the approach reduces computational complexity while improving detection accuracy.The proposed model demonstrates robust performance,achieving accuracies of 94.34%,99.95%,and 87.94%on the publicly available kitsune,Bot-IoT,and UNSW-NB15 datasets,respectively.Furthermore,its ability to detect zero-day attacks is validated through evaluations on two additional benchmark datasets,TON-IoT and IoT-23,using a Deep Federated Learning(DFL)framework,underscoring the generalization and effectiveness of the model in heterogeneous and decentralized IoT environments.Experimental results demonstrate superior performance over existing methods,establishing the proposed framework as an efficient and scalable solution for IoT security. 展开更多
关键词 Cyber-attack intrusion detection system(IDS) deep federated learning(DFL) zero-day attack distributed denial of services(DDoS) multi-class Internet of Things(IoT)
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Enhancing Multi-Class Cyberbullying Classification with Hybrid Feature Extraction and Transformer-Based Models
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作者 Suliman Mohamed Fati Mohammed A.Mahdi +4 位作者 Mohamed A.G.Hazber Shahanawaj Ahamad Sawsan A.Saad Mohammed Gamal Ragab Mohammed Al-Shalabi 《Computer Modeling in Engineering & Sciences》 2025年第5期2109-2131,共23页
Cyberbullying on social media poses significant psychological risks,yet most detection systems over-simplify the task by focusing on binary classification,ignoring nuanced categories like passive-aggressive remarks or... Cyberbullying on social media poses significant psychological risks,yet most detection systems over-simplify the task by focusing on binary classification,ignoring nuanced categories like passive-aggressive remarks or indirect slurs.To address this gap,we propose a hybrid framework combining Term Frequency-Inverse Document Frequency(TF-IDF),word-to-vector(Word2Vec),and Bidirectional Encoder Representations from Transformers(BERT)based models for multi-class cyberbullying detection.Our approach integrates TF-IDF for lexical specificity and Word2Vec for semantic relationships,fused with BERT’s contextual embeddings to capture syntactic and semantic complexities.We evaluate the framework on a publicly available dataset of 47,000 annotated social media posts across five cyberbullying categories:age,ethnicity,gender,religion,and indirect aggression.Among BERT variants tested,BERT Base Un-Cased achieved the highest performance with 93%accuracy(standard deviation across±1%5-fold cross-validation)and an average AUC of 0.96,outperforming standalone TF-IDF(78%)and Word2Vec(82%)models.Notably,it achieved near-perfect AUC scores(0.99)for age and ethnicity-based bullying.A comparative analysis with state-of-the-art benchmarks,including Generative Pre-trained Transformer 2(GPT-2)and Text-to-Text Transfer Transformer(T5)models highlights BERT’s superiority in handling ambiguous language.This work advances cyberbullying detection by demonstrating how hybrid feature extraction and transformer models improve multi-class classification,offering a scalable solution for moderating nuanced harmful content. 展开更多
关键词 Cyberbullying classification multi-class classification BERT models machine learning TF-IDF Word2Vec social media analysis transformer models
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A YOLOv11-Based Deep Learning Framework for Multi-Class Human Action Recognition
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作者 Nayeemul Islam Nayeem Shirin Mahbuba +4 位作者 Sanjida Islam Disha Md Rifat Hossain Buiyan Shakila Rahman M.Abdullah-Al-Wadud Jia Uddin 《Computers, Materials & Continua》 2025年第10期1541-1557,共17页
Human activity recognition is a significant area of research in artificial intelligence for surveillance,healthcare,sports,and human-computer interaction applications.The article benchmarks the performance of You Only... Human activity recognition is a significant area of research in artificial intelligence for surveillance,healthcare,sports,and human-computer interaction applications.The article benchmarks the performance of You Only Look Once version 11-based(YOLOv11-based)architecture for multi-class human activity recognition.The article benchmarks the performance of You Only Look Once version 11-based(YOLOv11-based)architecture for multi-class human activity recognition.The dataset consists of 14,186 images across 19 activity classes,from dynamic activities such as running and swimming to static activities such as sitting and sleeping.Preprocessing included resizing all images to 512512 pixels,annotating them in YOLO’s bounding box format,and applying data augmentation methods such as flipping,rotation,and cropping to enhance model generalization.The proposed model was trained for 100 epochs with adaptive learning rate methods and hyperparameter optimization for performance improvement,with a mAP@0.5 of 74.93%and a mAP@0.5-0.95 of 64.11%,outperforming previous versions of YOLO(v10,v9,and v8)and general-purpose architectures like ResNet50 and EfficientNet.It exhibited improved precision and recall for all activity classes with high precision values of 0.76 for running,0.79 for swimming,0.80 for sitting,and 0.81 for sleeping,and was tested for real-time deployment with an inference time of 8.9 ms per image,being computationally light.Proposed YOLOv11’s improvements are attributed to architectural advancements like a more complex feature extraction process,better attention modules,and an anchor-free detection mechanism.While YOLOv10 was extremely stable in static activity recognition,YOLOv9 performed well in dynamic environments but suffered from overfitting,and YOLOv8,while being a decent baseline,failed to differentiate between overlapping static activities.The experimental results determine proposed YOLOv11 to be the most appropriate model,providing an ideal balance between accuracy,computational efficiency,and robustness for real-world deployment.Nevertheless,there exist certain issues to be addressed,particularly in discriminating against visually similar activities and the use of publicly available datasets.Future research will entail the inclusion of 3D data and multimodal sensor inputs,such as depth and motion information,for enhancing recognition accuracy and generalizability to challenging real-world environments. 展开更多
关键词 Human activity recognition YOLOv11 deep learning real-time detection anchor-free detection attention mechanisms object detection image classification multi-class recognition surveillance applications
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3C产品钛合金结构件高速铣削刀具研究
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作者 师润平 吴交 《工具技术》 北大核心 2026年第2期111-119,共9页
为解决小功率加工中心对加工效率的制约,3C产品钛合金结构件加工需要满足“大转速、小进给”加工条件的小规格高速铣刀。在利用有限元软件对螺旋角、前角、后角进行仿真优化的基础上,制备硬质合金四刃立铣刀样刀,通过高速铣削Ti6Al4V的... 为解决小功率加工中心对加工效率的制约,3C产品钛合金结构件加工需要满足“大转速、小进给”加工条件的小规格高速铣刀。在利用有限元软件对螺旋角、前角、后角进行仿真优化的基础上,制备硬质合金四刃立铣刀样刀,通过高速铣削Ti6Al4V的单因素实验优选刀具的螺旋槽型、齿距角和材质,并对仿真优化得到的不同前后角组合方案进行寿命对比实验,得出最优刀具几何参数组合和优选的材质。与国外铣刀的相同切削条件对比实验表明,采用优化几何参数和优选材质的铣刀能够满足100 m·min^(-1)以上的切削速度,性能与进口刀具相当。 展开更多
关键词 钛合金 高速铣刀 几何参数优化 刀具材料 耐用度
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具有修正的Min(N,D)-策略和单重休假的Geo/G/1离散时间排队分析
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作者 魏瑛源 余玅妙 唐玉玲 《应用数学》 北大核心 2026年第1期108-128,共21页
本文研究服务员具有单重休假和系统采用修正的Min(N,D)-策略的离散时间Geo/G/1排队系统,运用更新过程理论、全概率分解技术和z-变换工具,从任意初始状态开始,研究队长的瞬时性态和平稳性态,得到了任意时刻n^(+)处队长瞬态分布的z-变换... 本文研究服务员具有单重休假和系统采用修正的Min(N,D)-策略的离散时间Geo/G/1排队系统,运用更新过程理论、全概率分解技术和z-变换工具,从任意初始状态开始,研究队长的瞬时性态和平稳性态,得到了任意时刻n^(+)处队长瞬态分布的z-变换表达式和稳态分布的递推表达式,同时给出了不同时刻n^(-)、n、n^(+)和外部观测点处队长稳态分布之间的重要关系.进一步借助于数值实例,讨论了系统的空闲率与稳态平均队长关于系统参数的敏感性,并且阐述了便于作数值计算的队长稳态分布的递推公式在系统容量优化设计中的重要价值.最后,运用更新报酬过程定理,建立了费用结构模型,获得了系统长期运行下单位时间内所产生的期望费用的显示表达式,并通过数值算例,寻求使期望费用最小的最优控制策略(N^(*),D^(*)). 展开更多
关键词 离散时间排队 修正的Min(N D)-策略 单重休假 队长分布 系统容量优化设计 最优控制策略
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Decision-making of Aircraft Optimum Configuration Utilizing Multidimensional Game Theory 被引量:1
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作者 彭润艳 王和平 +1 位作者 王正平 林宇 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2010年第2期194-197,共4页
As multi-discipline coupling and components interference often affect the aircraft configuration decision-making and analysis during conceptual design process, this article presents an approach of multidimensional gam... As multi-discipline coupling and components interference often affect the aircraft configuration decision-making and analysis during conceptual design process, this article presents an approach of multidimensional game theory based on aircraft compo- nents to deal with this problem. The idea is that the configuration decision-making process is regarded as the game for different disciplines and technologies, and the aircraft components are players. The payoff function with highest total gain means that ac- cording to the game protocols and multidimensional theory, the optimal aircraft configuration within the strategy set will be cho- sen. The decision-making model is applied to conceptual design process of the high altitude long endurance (HALE) unmanned aerial vehicle (UAV) based on the assessment of technological risk. The obtained optimum configuration is quite consistent with the current HALE UAV development trends. Thus, taking into account the coupling and interference factors, the multidimensional gaming model based on aircraft components will be an effective analysis method in the decision-making process of aircraft optimum configuration. 展开更多
关键词 decision making optimum configuration components interference multidimensional game theory disciplines coupling technological risk
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Analysis and Optimum Design of Differential Inductors Using Distributed Capacitance Model 被引量:1
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作者 菅洪彦 唐长文 +1 位作者 何捷 闵昊 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2005年第6期1077-1082,共6页
A distributed capacitance model for monolithic inductors is developed to predict the equivalently parasitical capacitances of the inductor.The ratio of the self-resonant frequency (f SR) of the differential-driven sym... A distributed capacitance model for monolithic inductors is developed to predict the equivalently parasitical capacitances of the inductor.The ratio of the self-resonant frequency (f SR) of the differential-driven symmetric inductor to the f SR of the single-ended driven inductor is firstly predicted and explained.Compared with a single-ended configuration,experimental data demonstrate that the differential inductor offers a 127% greater maximum quality factor and a broader range of operating frequencies.Two differential inductors with low parasitical capacitance are developed and validated. 展开更多
关键词 distributed capacitance model self-resonant frequency ratio quality factor differential inductor optimum design
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OPTIMUM OF PRESSURE RATIOS OF MULTI-STAGE RECIPROCATING COMPRESSOR WITH PRACTICAL INTER-COOLING 被引量:1
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作者 刘卫华 昂海松 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2002年第2期177-181,共5页
The optimum pressure ratio distribution of a multistage reciprocating compressor is presented based on the assumption, i.e. the inter stage cooling is perfect and there are no pressure losses. The optimization of the... The optimum pressure ratio distribution of a multistage reciprocating compressor is presented based on the assumption, i.e. the inter stage cooling is perfect and there are no pressure losses. The optimization of the two or three stage pressure ratio is analyzed in two cases of constant heat transfer rate for the inter cooler or constant inter stage inlet temperature, based on the minimum of the sum of theoretical compression power at each stage about a multi stage reciprocating compressor. Furthermore, with an example of two stage compressor the influence on the sum of the power of each stage is analyzed when practical pressure ratio deviates from the optimum value. It is obtained that under different cooling conditions the optimum pressure ratio distribution of the multi stage compression is various, and the change of the optimum pressure ratio within a small range has little influence on the sum of the power each stage. For the two stage compression, this range can be represented as ε 1=(0 96~1 06)ε 1j . 展开更多
关键词 inter cooler multi stage compressor pressure ratio optimum
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北部湾棕斑兔头鲀生长、死亡和单位补充量渔获量研究
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作者 徐浩 黄亮亮 +7 位作者 王才广 承亚男 苏琼源 杨伊恒 宋建强 胥鹏 康斌 吴志强 《海洋渔业》 北大核心 2026年第2期129-137,共9页
为了解北部湾棕斑兔头鲀(Lagocephalus spadiceus)的生物学特征和种群资源现状,根据2021年3、9月,2022年4、8月和2023年9月调查数据,采用ELEFAN I方法与体长变换渔获率曲线估算棕斑兔头鲀的生物学参数和总死亡系数,并利用Beverton-Holt... 为了解北部湾棕斑兔头鲀(Lagocephalus spadiceus)的生物学特征和种群资源现状,根据2021年3、9月,2022年4、8月和2023年9月调查数据,采用ELEFAN I方法与体长变换渔获率曲线估算棕斑兔头鲀的生物学参数和总死亡系数,并利用Beverton-Holt单位补充量渔获量模型评估北部湾棕斑兔头鲀资源状况,同时结合拐点年龄ttp和临界年龄T_(c)确定其最适开捕体长L_(c)。结果表明:棕斑兔头鲀体长为41.10~228.73 mm;体质量为1.70~415.53 g;体长-体质量关系W=8.598×10^(-5)L^(2.816)(R^(2)=0.9447,n=691)。Von Bertalanffy生长方程参数:生长系数K、渐近体长L_(∞)和理论初始年龄t_(0)分别为0.27、240.15 mm和-0.349 a,生长表现指数∅为4.19。总死亡系数Z、自然死亡系数M和捕捞死亡系数F分别为1.28、0.42和0.86。开发率E为0.67,产量最大开发率E_(max)为0.53,开发率E高于产量最大开发率E_(max),处于过度开发状态。拐点年龄ttp为3.49 a,拐点体长为155.17 mm;临界年龄T_(c)为3.48 a,临界体长为154.74 mm。综合考虑补充群体及资源可持续性,建议将最适开捕体长L_(c)设置为130.00 mm。研究结果可为北部湾棕斑兔头鲀资源开发以及渔业生态系统研究提供参考。 展开更多
关键词 棕斑兔头鲀 生物学参数 最适开捕体长 北部湾
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Study on Optimum Fertilization Model of Potato Intercropped with Sugarcane
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作者 江泽普 廖青 +5 位作者 谭裕模 韦广泼 邢颖 汪羽宁 刘斌 梁潘霞 《Agricultural Science & Technology》 CAS 2013年第1期138-143,共6页
[Objective] The paper was to study the effects of different ratios of N, P and K on yield of potato intercropped with sugarcane in Lateritic red earth area of Guangxi, and seek the best N, P and K ratio for nutrition ... [Objective] The paper was to study the effects of different ratios of N, P and K on yield of potato intercropped with sugarcane in Lateritic red earth area of Guangxi, and seek the best N, P and K ratio for nutrition model of potato inter- cropped with sugarcane. [Method]Two field experiments adopted the optimum com- pound design (311-A) were conducted in Long'an County of Guangxi Province in 2011 and 2012, respectively. The polynomial regression models of fertilizer applica- tion and quadratic of three factors were established by SAS statistical analysis soft- ware, and optimum nutrient simulation models of potato were obtained by computer processing. [Result] The combined application of low nitrogen and mid-high potassi- um and phosphorus fertilizer contributed to higher potato yield in experimental condi- tion. The regression model of potato yield (Yll and Y12) and dosage of N(X1), P (X2), K(X3) were established by using SAS statistical analysis software, in 2011 and 2012, respectively. They were Y11 =14 725.28 -415.39X1 +741.99X2 +607.83)(3-447.92X1X2- 144.09X1X3 -405.83X2X3 -267.82X1^2-795.67X2^2 -642.10X3^2, R =0.927 2; and Y12 =14 342.60 -896.25X1 +548.62X2 +925.51 X3 +67.81 X1X2 +531.60X1X3 -99.00X2X3 -904.00X1^2 - 1121.36X2^2-596.64X3^2,R=0.926 6. The regression mathematics model of potato yields preferably fit with actual situation in the locality, and have higher practical value, so it could be used for fertilizer decision and forecast. Using the computer to carry on the optimization, the N, P and K dosage of the best potato yield intercropped with sugarcane was obtained. The dosage of N, P2O5, K2O were 108.8-140.6, 172.5-204.4 and 285.9 kg/hm2, respectively. [Conclusion] The best N, P and K ratio of potato yield intercropped with sugarcane was 1:(1.23-1.68):(2.03-2.63). 展开更多
关键词 INTERCROPPING optimum fertilization model Sugarcane-Potato
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Time varying congestion pricing for multi-class and multi-mode transportation system with asymmetric cost functions
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作者 钟绍鹏 邓卫 《Journal of Southeast University(English Edition)》 EI CAS 2011年第1期77-82,共6页
This paper considers the problem of time varying congestion pricing to determine optimal time-varying tolls at peak periods for a queuing network with the interactions between buses and private cars.Through the combin... This paper considers the problem of time varying congestion pricing to determine optimal time-varying tolls at peak periods for a queuing network with the interactions between buses and private cars.Through the combined applications of the space-time expanded network(STEN) and the conventional network equilibrium modeling techniques,a multi-class,multi-mode and multi-criteria traffic network equilibrium model is developed.Travelers of different classes have distinctive value of times(VOTs),and travelers from the same class perceive their travel disutility or generalized costs on a route according to different weights of travel time and travel costs.Moreover,the symmetric cost function model is extended to deal with the interactions between buses and private cars.It is found that there exists a uniform(anonymous) link toll pattern which can drive a multi-class,multi-mode and multi-criteria user equilibrium flow pattern to a system optimum when the system's objective function is measured in terms of money.It is also found that the marginal cost pricing models with a symmetric travel cost function do not reflect the interactions between traffic flows of different road sections,and the obtained congestion pricing toll is smaller than the real value. 展开更多
关键词 time varying congestion pricing ASYMMETRIC multi-class MULTI-MODE MULTI-CRITERIA
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Is There an Optimum Age For Foreign Language Learning?
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作者 兰军 《陕西师范大学学报(哲学社会科学版)》 CSSCI 北大核心 2001年第S2期334-336,共3页
Age is one of the factors which influnce foreign language learning, but not the most important one. Comparision on the effect of foreign language learning between adults and children cannot rely merely on age. So the ... Age is one of the factors which influnce foreign language learning, but not the most important one. Comparision on the effect of foreign language learning between adults and children cannot rely merely on age. So the question of an optimum age for foreign language learning is not a simple one which is only related to age. There are different optimum ages for different aims and demands of learning foreign language. 展开更多
关键词 optimum age FOREIGN LANGUAGE LEARNING ADULT CHILDREN
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OPTIMUM CUTTING ANALYSIS METHOD OF MEMBRANE STRUCTURE
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作者 邵小方 吴健生 《Transactions of Tianjin University》 EI CAS 1995年第2期189+186-187,189,共4页
By the optimum theory, a new cutting analytical method of the membrane structure is developed. The B-spline curve is applied to make smooth the boundary of the membrane strip. By this method, the cutting accuracy is i... By the optimum theory, a new cutting analytical method of the membrane structure is developed. The B-spline curve is applied to make smooth the boundary of the membrane strip. By this method, the cutting accuracy is improved. Finally, a cutting analysis example of a tension membrane structure is given. 展开更多
关键词 membrane structure cutting analysis optimum theory
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Optimum Design of Impedance Simulator for Phased Array Antnnas
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作者 吕昕 李世智 《Journal of Beijing Institute of Technology》 EI CAS 1994年第1期63+59-63,共6页
The impedance of a solid state active phased array antenna varing with frequency and beam scanning scanning angle be matched with the solid state active matching network (SSAMN). In order to adjust and measure the rad... The impedance of a solid state active phased array antenna varing with frequency and beam scanning scanning angle be matched with the solid state active matching network (SSAMN). In order to adjust and measure the radar conveniently and Securely, it is necessary for the impedance of the simulator of the phased array antennas to be optimized.Having selected the PIN dilde controlling circuits and the circuit parameters optimized,the simulator circuit is determined through numerical computation The experiment is given in support of the simulation. 展开更多
关键词 phase array antennas impedance inatching simulation optimum design active circuits
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半主动悬挂式采摘机器人运动控制研究
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作者 谢行 吕高晨 +1 位作者 任梦 乔雪涛 《机械设计与制造》 北大核心 2026年第3期344-348,共5页
复杂地形下机器人的稳定性始终是制约其推广应用的核心问题。本研究以轮式采摘机器人为目标对象,设计半主动式悬挂系统增强其稳定性。基于运动学方法建立了机器人系统的动力学模型,设计LQR控制器,以机器人垂向加速度,悬挂动位移和轮胎... 复杂地形下机器人的稳定性始终是制约其推广应用的核心问题。本研究以轮式采摘机器人为目标对象,设计半主动式悬挂系统增强其稳定性。基于运动学方法建立了机器人系统的动力学模型,设计LQR控制器,以机器人垂向加速度,悬挂动位移和轮胎动位移为目标,采用遗传算法优化加权系数,确定最优控制策略。研究中对遗传算法中不同参数对优化结果的影响进行了探讨,表明种群个数对控制器效果具有重要影响。在最优控制策略下,进一步对比了不同路面特征下的机器人响应特性,结果表明设计的控制器对不同路面具有较好的适用性。最后对控制系统的鲁棒性进行了分析,在结构参数变化时控制系统能够起到正常的控制作用。研究结果对改善移动机器人不同路面行驶的稳定性具有重要参考意义。 展开更多
关键词 采摘机器人 动力学模型 最优控制 遗传算法 鲁棒性分析
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DYNAMICAL OPTIMUM DESIGN OF THE MECHANICAL OSCILLATION SYSTEM IN FLUIDIC GENERATOR
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作者 李福松 陈建军 《兵工学报》 EI CAS CSCD 北大核心 2000年第1期-,共4页
文中通过对射流发电机工作原理、结构特点及作用荷载的分析,建立了射流发电机机械振动系统的动力优化设计数学模型,以结构尺寸为设计变量,使结构重量极小化,满足动力位移、应力响应、基频以及尺寸限等约束条件,利用振型迭加法和复... 文中通过对射流发电机工作原理、结构特点及作用荷载的分析,建立了射流发电机机械振动系统的动力优化设计数学模型,以结构尺寸为设计变量,使结构重量极小化,满足动力位移、应力响应、基频以及尺寸限等约束条件,利用振型迭加法和复合形法求解。优化和试验结果表明:经优化后,既减轻结构重量,又显著地提高了射流发电机的输出功率。 展开更多
关键词 引信 射流技术 电源 有限元法 动力响应 动力优化 DYNAMICAL optimum DESIGN OF THE MECHANICAL
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纳什均衡微分博弈策略的车队优化控制
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作者 李媛婧 赵娜 《机械设计与制造》 北大核心 2026年第1期186-195,200,共11页
为了保证自动驾驶车队控制的高效性和实用性,提出了一种基于近邻纳什均衡微分博弈策略的车队优化控制方法。首先引入非合作微分博弈理论来分析车队中各车辆的决策行为,并利用递归地平线纳什均衡来测量车辆间动态相互作用的关联性,进而... 为了保证自动驾驶车队控制的高效性和实用性,提出了一种基于近邻纳什均衡微分博弈策略的车队优化控制方法。首先引入非合作微分博弈理论来分析车队中各车辆的决策行为,并利用递归地平线纳什均衡来测量车辆间动态相互作用的关联性,进而对控制策略进行排序,从而快速缩小搜索空间。然后,在优化阶段提出了一种基于相对动力学的转换机制,有效放大了稳定且性能良好的控制策略的影响,同时避免了陷入局部最优解。另外,引入了一种结合车队稳定性和控制成本的多目标评价指标,以加强在多样化场景下的搜索效率。最后,通过在多个模拟驾驶场景中比较结果,证明了所提车队控制策略优化方法的有效性和适用性。 展开更多
关键词 纳什均衡 微分博弈 局部最优 多目标评价 车队控制
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基于VOF和DPM的离心式喷头数值模拟及结构优化
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作者 黄超然 潘葆 +6 位作者 李果 王玉 刘所恩 赵俊波 王鹏飞 石玉银 谭凯鑫 《农业装备与车辆工程》 2026年第1期87-92,共6页
为提高离心式雾化喷头在工业现场应用的综合性能,基于VOF与DPM方法,采用Fluent软件对喷头内外流场进行数值模拟。结合正交试验设计与综合评分法,分析了收敛段角度、节流孔直径、节流孔长度及内芯螺旋角等结构参数对喷头质量流率与雾化... 为提高离心式雾化喷头在工业现场应用的综合性能,基于VOF与DPM方法,采用Fluent软件对喷头内外流场进行数值模拟。结合正交试验设计与综合评分法,分析了收敛段角度、节流孔直径、节流孔长度及内芯螺旋角等结构参数对喷头质量流率与雾化角度等喷洒特性的影响规律,并在此基础上完成结构优化。结果表明,当收敛段角度为25°、节流孔直径1.5 mm、节流孔长度2.5 mm、内芯螺旋角45°时,喷头综合性能最优。 展开更多
关键词 离心式喷头 数值模拟 正交实验 结构优化
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