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Digital Twin-Assisted Semi-Federated Learning Framework for Industrial Edge Intelligence
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作者 Wu Xiongyue Tang Jianhua Marie Siew 《China Communications》 SCIE CSCD 2024年第5期314-329,共16页
The rapid development of emerging technologies,such as edge intelligence and digital twins,have added momentum towards the development of the Industrial Internet of Things(IIo T).However,the massive amount of data gen... The rapid development of emerging technologies,such as edge intelligence and digital twins,have added momentum towards the development of the Industrial Internet of Things(IIo T).However,the massive amount of data generated by the IIo T,coupled with heterogeneous computation capacity across IIo T devices,and users’data privacy concerns,have posed challenges towards achieving industrial edge intelligence(IEI).To achieve IEI,in this paper,we propose a semi-federated learning framework where a portion of the data with higher privacy is kept locally and a portion of the less private data can be potentially uploaded to the edge server.In addition,we leverage digital twins to overcome the problem of computation capacity heterogeneity of IIo T devices through the mapping of physical entities.We formulate a synchronization latency minimization problem which jointly optimizes edge association and the proportion of uploaded nonprivate data.As the joint problem is NP-hard and combinatorial and taking into account the reality of largescale device training,we develop a multi-agent hybrid action deep reinforcement learning(DRL)algorithm to find the optimal solution.Simulation results show that our proposed DRL algorithm can reduce latency and have a better convergence performance for semi-federated learning compared to benchmark algorithms. 展开更多
关键词 digital twin edge association industrial edge intelligence(IEI) semi-federated learning
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Ada-FFL:Adaptive computing fairness federated learning
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作者 Yue Cong Jing Qiu +4 位作者 Kun Zhang Zhongyang Fang Chengliang Gao Shen Su Zhihong Tian 《CAAI Transactions on Intelligence Technology》 SCIE EI 2024年第3期573-584,共12页
As the scale of federated learning expands,solving the Non-IID data problem of federated learning has become a key challenge of interest.Most existing solutions generally aim to solve the overall performance improveme... As the scale of federated learning expands,solving the Non-IID data problem of federated learning has become a key challenge of interest.Most existing solutions generally aim to solve the overall performance improvement of all clients;however,the overall performance improvement often sacrifices the performance of certain clients,such as clients with less data.Ignoring fairness may greatly reduce the willingness of some clients to participate in federated learning.In order to solve the above problem,the authors propose Ada-FFL,an adaptive fairness federated aggregation learning algorithm,which can dynamically adjust the fairness coefficient according to the update of the local models,ensuring the convergence performance of the global model and the fairness between federated learning clients.By integrating coarse-grained and fine-grained equity solutions,the authors evaluate the deviation of local models by considering both global equity and individual equity,then the weight ratio will be dynamically allocated for each client based on the evaluated deviation value,which can ensure that the update differences of local models are fully considered in each round of training.Finally,by combining a regularisation term to limit the local model update to be closer to the global model,the sensitivity of the model to input perturbations can be reduced,and the generalisation ability of the global model can be improved.Through numerous experiments on several federal data sets,the authors show that our method has more advantages in convergence effect and fairness than the existing baselines. 展开更多
关键词 adaptive fariness aggregation FAIRNESS federated learning non-IID
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6G New Multiple Access Technology
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作者 Yifei Yuan Yongpeng Wu +3 位作者 Lei Wang Zhifeng Yuan Wei Bai Yuanwei Liu 《China Communications》 SCIE CSCD 2024年第1期I0002-I0005,共4页
As a basic technology at physical layer of mobile communications,non-orthogonal multiple access has been attracting wide attention across the academia and the industry.During the standardization of the fifth-generatio... As a basic technology at physical layer of mobile communications,non-orthogonal multiple access has been attracting wide attention across the academia and the industry.During the standardization of the fifth-generation(5G)of mobile communications,3GPP conducted preliminary study on non-orthogonal multiple access without reaching the consensus to standardize the technology. 展开更多
关键词 TECHNOLOGY ACCESS attracting
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Mutual information oriented deep skill chaining for multi‐agent reinforcement learning
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作者 Zaipeng Xie Cheng Ji +4 位作者 Chentai Qiao WenZhan Song Zewen Li Yufeng Zhang Yujing Zhang 《CAAI Transactions on Intelligence Technology》 SCIE EI 2024年第4期1014-1030,共17页
Multi‐agent reinforcement learning relies on reward signals to guide the policy networks of individual agents.However,in high‐dimensional continuous spaces,the non‐stationary environment can provide outdated experi... Multi‐agent reinforcement learning relies on reward signals to guide the policy networks of individual agents.However,in high‐dimensional continuous spaces,the non‐stationary environment can provide outdated experiences that hinder convergence,resulting in ineffective training performance for multi‐agent systems.To tackle this issue,a novel reinforcement learning scheme,Mutual Information Oriented Deep Skill Chaining(MioDSC),is proposed that generates an optimised cooperative policy by incorporating intrinsic rewards based on mutual information to improve exploration efficiency.These rewards encourage agents to diversify their learning process by engaging in actions that increase the mutual information between their actions and the environment state.In addition,MioDSC can generate cooperative policies using the options framework,allowing agents to learn and reuse complex action sequences and accelerating the convergence speed of multi‐agent learning.MioDSC was evaluated in the multi‐agent particle environment and the StarCraft multi‐agent challenge at varying difficulty levels.The experimental results demonstrate that MioDSC outperforms state‐of‐the‐art methods and is robust across various multi‐agent system tasks with high stability. 展开更多
关键词 artificial intelligence techniques decision making intelligent multi‐agent systems
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Complexity Considerations in the Heisenberg Uncertainty Principle
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作者 Logan Nye 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第4期1470-1513,共44页
This work introduces a modification to the Heisenberg Uncertainty Principle (HUP) by incorporating quantum complexity, including potential nonlinear effects. Our theoretical framework extends the traditional HUP to co... This work introduces a modification to the Heisenberg Uncertainty Principle (HUP) by incorporating quantum complexity, including potential nonlinear effects. Our theoretical framework extends the traditional HUP to consider the complexity of quantum states, offering a more nuanced understanding of measurement precision. By adding a complexity term to the uncertainty relation, we explore nonlinear modifications such as polynomial, exponential, and logarithmic functions. Rigorous mathematical derivations demonstrate the consistency of the modified principle with classical quantum mechanics and quantum information theory. We investigate the implications of this modified HUP for various aspects of quantum mechanics, including quantum metrology, quantum algorithms, quantum error correction, and quantum chaos. Additionally, we propose experimental protocols to test the validity of the modified HUP, evaluating their feasibility with current and near-term quantum technologies. This work highlights the importance of quantum complexity in quantum mechanics and provides a refined perspective on the interplay between complexity, entanglement, and uncertainty in quantum systems. The modified HUP has the potential to stimulate interdisciplinary research at the intersection of quantum physics, information theory, and complexity theory, with significant implications for the development of quantum technologies and the understanding of the quantum-to-classical transition. 展开更多
关键词 UNCERTAINTY COMPLEXITY QUANTUM MEASUREMENT INFORMATION ENTANGLEMENT
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The Emergence of Time from Quantum Information Dynamics
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作者 Logan Nye 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第4期1981-2006,共26页
This paper presents a novel framework for understanding time as an emergent phenomenon arising from quantum information dynamics. We propose that the flow of time and its directional arrow are intrinsically linked to ... This paper presents a novel framework for understanding time as an emergent phenomenon arising from quantum information dynamics. We propose that the flow of time and its directional arrow are intrinsically linked to the growth of quantum complexity and the evolution of entanglement entropy in physical systems. By integrating principles from quantum mechanics, information theory, and holography, we develop a comprehensive theory that explains how time can emerge from timeless quantum processes. Our approach unifies concepts from quantum mechanics, general relativity, and thermodynamics, providing new perspectives on longstanding puzzles such as the black hole information paradox and the arrow of time. We derive modified Friedmann equations that incorporate quantum information measures, offering novel insights into cosmic evolution and the nature of dark energy. The paper presents a series of experimental proposals to test key aspects of this theory, ranging from quantum simulations to cosmological observations. Our framework suggests a deeply information-theoretic view of the universe, challenging our understanding of the nature of reality and opening new avenues for technological applications in quantum computing and sensing. This work contributes to the ongoing quest for a unified theory of quantum gravity and information, potentially with far-reaching implications for our understanding of space, time, and the fundamental structure of the cosmos. 展开更多
关键词 TIME ENTROPY EMERGENCE Black Hole Information Paradox Complexity ENTANGLEMENT Quantum Information
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Quantum Extensions to the Einstein Field Equations
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作者 Logan Nye 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第4期2007-2031,共25页
This paper proposes an extension to the Einstein Field Equations by integrating quantum informational measures, specifically entanglement entropy and quantum complexity. These modified equations aim to bridge the gap ... This paper proposes an extension to the Einstein Field Equations by integrating quantum informational measures, specifically entanglement entropy and quantum complexity. These modified equations aim to bridge the gap between general relativity and quantum mechanics, offering a unified framework that incorporates the geometric properties of spacetime with fundamental aspects of quantum information theory. The theoretical implications of this approach include potential resolutions to longstanding issues like the black hole information paradox and new perspectives on dark energy. The paper presents modified versions of classical solutions such as the Schwarzschild metric and Friedmann equations, incorporating quantum corrections. It also outlines testable predictions in areas including gravitational wave propagation, black hole shadows, and cosmological observables. We propose several avenues for future research, including exploring connections with other quantum gravity approaches designing experiments to test the theory’s predictions. This work contributes to the ongoing exploration of quantum gravity, offering a framework that potentially unifies general relativity and quantum mechanics with testable predictions. 展开更多
关键词 Quantum Mechanics COMPLEXITY Entanglement Entropy GRAVITY General Relativity Information
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How Does Naming Affect Language Models on Code Analysis Tasks?
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作者 Zhilong Wang Lan Zhang +3 位作者 Chen Cao Nanqing Luo Xinzhi Luo Peng Liu 《Journal of Software Engineering and Applications》 2024年第11期803-816,共14页
The Large Language Models (LLMs), such as GPT and BERT, were proposed for natural language processing (NLP) and have shown promising results as general-purpose language models. An increasing number of industry profess... The Large Language Models (LLMs), such as GPT and BERT, were proposed for natural language processing (NLP) and have shown promising results as general-purpose language models. An increasing number of industry professionals and researchers are adopting LLMs for program analysis tasks. However, one significant difference between programming languages and natural languages is that a programmer has the flexibility to assign any names to variables, methods, and functions in the program, whereas a natural language writer does not. Intuitively, the quality of naming in a program affects the performance of LLMs in program analysis tasks. This paper investigates how naming affects LLMs on code analysis tasks. Specifically, we create a set of datasets with code containing nonsense or misleading names for variables, methods, and functions, respectively. We then use well-trained models (CodeBERT) to perform code analysis tasks on these datasets. The experimental results show that naming has a significant impact on the performance of code analysis tasks based on LLMs, indicating that code representation learning based on LLMs heavily relies on well-defined names in code. Additionally, we conduct a case study on some special code analysis tasks using GPT, providing further insights. 展开更多
关键词 LLMs CodeBERT Code Analysis
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下穿铁路斜交框架桥顶进施工技术分析与应用研究
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作者 王金龙 王子轩 朱光昊 《山东交通科技》 2024年第5期42-46,共5页
以元氏县盛元路下穿京广铁路框架桥为例,对下穿铁路框架桥的顶进施工技术及应用进行分析。介绍了顶推法框架桥的施工准备,阐述了顶推过程中的技术要点、测量控制和安全控制措施。案例实测数据和理论值分析结果表明,顶推法施工有效减少... 以元氏县盛元路下穿京广铁路框架桥为例,对下穿铁路框架桥的顶进施工技术及应用进行分析。介绍了顶推法框架桥的施工准备,阐述了顶推过程中的技术要点、测量控制和安全控制措施。案例实测数据和理论值分析结果表明,顶推法施工有效减少了对铁路运输的影响。 展开更多
关键词 下穿铁路 框架桥 斜交 顶推法施工 技术分析
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眼动数据可视化综述 被引量:30
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作者 程时伟 孙凌云 《计算机辅助设计与图形学学报》 EI CSCD 北大核心 2014年第5期698-707,共10页
随着眼动跟踪技术在实际应用中的普及,大量眼动数据需要通过合理的可视化方式进行处理与分析,在这种背景下,眼动数据可视化在基础理论、方法和应用研究等方面得到了快速发展.文中总结了眼动数据的预处理与参数化方法,并在此基础上介绍... 随着眼动跟踪技术在实际应用中的普及,大量眼动数据需要通过合理的可视化方式进行处理与分析,在这种背景下,眼动数据可视化在基础理论、方法和应用研究等方面得到了快速发展.文中总结了眼动数据的预处理与参数化方法,并在此基础上介绍了眼动数据可视化的基本框架和4种主要可视化方法:扫描路径法、热区图法、感兴趣区法和三维空间法;进而介绍了眼动数据可视化在用户界面可用性评估等方面的应用实例.最后对眼动数据可视化未来的研究趋势进行了展望. 展开更多
关键词 眼动跟踪 可视化 热区图 扫描路径 可视分析 人机交互
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用于移动设备人机交互的眼动跟踪方法 被引量:18
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作者 程时伟 孙志强 《计算机辅助设计与图形学学报》 EI CSCD 北大核心 2014年第8期1354-1361,共8页
传统眼动跟踪设备构造复杂、体积和重量大,通常只能以桌面固定方式使用,无法支持普适计算环境下的移动式交互.为此,提出一种面向移动式交互的眼动跟踪方法,包括眼动图像处理、眼动特征检测、眼动数据计算和眼动交互应用4个层次.首先对... 传统眼动跟踪设备构造复杂、体积和重量大,通常只能以桌面固定方式使用,无法支持普适计算环境下的移动式交互.为此,提出一种面向移动式交互的眼动跟踪方法,包括眼动图像处理、眼动特征检测、眼动数据计算和眼动交互应用4个层次.首先对眼球红外图像进行滤波、二值化处理,进而基于瞳孔-角膜反射法,结合二次定位和改进的椭圆拟合方法检测瞳孔,设计缩放因子驱动的模板匹配法检测普洱钦斑;在此基础上,计算注视点坐标等眼动数据;最后设计与开发了一个基于单个红外摄像头的头戴式眼动跟踪原型系统.实际用户测试结果表明,该系统舒适度适中,并具有较高精度和鲁棒性,从而验证了文中方法在移动式交互中的可行性和有效性. 展开更多
关键词 眼动跟踪 瞳孔-角膜反射法 普洱钦斑 移动设备 人机交互
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面向多设备交互的眼动跟踪方法 被引量:10
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作者 程时伟 孙志强 陆煜华 《计算机辅助设计与图形学学报》 EI CSCD 北大核心 2016年第7期1094-1104,共11页
当前,越来越多的人机交互应用需要依靠多个设备共同完成,传统针对单个设备的眼动跟踪方法已很难适应多设备交互的需求.为此,提出一种面向多设备交互的眼动跟踪方法.针对用户眼球运动幅度显著变大给图像识别带来的影响,采用待选瞳孔区域... 当前,越来越多的人机交互应用需要依靠多个设备共同完成,传统针对单个设备的眼动跟踪方法已很难适应多设备交互的需求.为此,提出一种面向多设备交互的眼动跟踪方法.针对用户眼球运动幅度显著变大给图像识别带来的影响,采用待选瞳孔区域和瞳孔中心识别相结合的方法识别瞳孔;同时对普洱钦斑位置进行预测,插补识别过程中丢失的普洱钦斑;在此基础上,建立瞳孔-普洱钦斑反射向量.另一方面,利用边缘检测方法识别设备屏幕,并通过建立不同设备屏幕的顶点位置列表,比较屏幕形状和面积以区分不同设备;再根据瞳孔-普洱钦斑反射向量进行眼动注视点坐标拟合计算,并结合头部运动误差补偿方法提高多设备之间眼动注视点坐标的计算精度.最后设计开发了头戴式眼动跟踪系统Multi Gaze,用户测试结果表明,文中方法在多设备交互环境下能有效地提高注视点计算精度. 展开更多
关键词 眼动跟踪 注视点 多设备 人机交互
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条带式加筋土挡墙模型试验研究 被引量:2
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作者 石朗晶 李贤 +2 位作者 骆龙炳 王冯哲 曹烨楠 《西南师范大学学报(自然科学版)》 CAS CSCD 北大核心 2013年第6期136-140,共5页
通过进行加筋挡土墙的模型试验研究,初步探讨了加筋挡土墙结构工作的基本原理.发现加筋土挡墙的作用机理主要是由于筋带对土体的加筋作用改善了挡墙的变形特性,保证了挡土墙的稳定.加筋土挡墙最大位移通常发生在中部偏下处,挡墙工作中... 通过进行加筋挡土墙的模型试验研究,初步探讨了加筋挡土墙结构工作的基本原理.发现加筋土挡墙的作用机理主要是由于筋带对土体的加筋作用改善了挡墙的变形特性,保证了挡土墙的稳定.加筋土挡墙最大位移通常发生在中部偏下处,挡墙工作中处于距底部高度为1/3处面板滑移最大.有限元计算与按规范计算出的滑裂面有明显差异,在挡墙中部及以下,两者的滑裂面形状类似,但是在挡墙上部,有限元法所得与规范推荐破裂面相差很大,规范推荐破裂面有一定的局限性,在设计时应考虑用其他方法补充计算,确保结构安全. 展开更多
关键词 加筋土挡墙 模型试验 内部破裂面 有限元分析
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金融支持县域经济发展的方式创新研究——基于供给侧结构性改革的视角 被引量:4
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作者 宋志秀 宋俊怡 《中国集体经济》 2017年第8期16-18,共3页
县域经济是国民经济的重要组成部分,是我国未来经济的重要引擎之一。推进县域供给侧结构性改革是在经济新常态下县域经济发展的必然选择和实现路径,是实现精准扶贫、精准脱贫和全面建成小康社会目标的坚实保障。文章分析了县域供给侧结... 县域经济是国民经济的重要组成部分,是我国未来经济的重要引擎之一。推进县域供给侧结构性改革是在经济新常态下县域经济发展的必然选择和实现路径,是实现精准扶贫、精准脱贫和全面建成小康社会目标的坚实保障。文章分析了县域供给侧结构性改革的特点以及为金融服务县域经济提供的历史性机遇和广阔空间,指出金融服务县域经济存在的矛盾,就县域供给侧结构性改革背景下金融服务县域经济的创新方式进行探索并给出建议。 展开更多
关键词 县域经济 供给侧结构性改革 创新 金融服务方式
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简约空间内点法的投影梯度可行性恢复
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作者 王可心 邵之江 Lorenz T Biegler 《华东理工大学学报(自然科学版)》 CAS CSCD 北大核心 2014年第3期332-337,共6页
内点法作为一种高效的非线性规划算法,其简约空间算法实现尤其适于求解过程系统工程中的高维、低自由度优化问题,从而算法只需要在决策变量的低维空间寻求最优解,并且求解性能不依赖于模型的精确二阶导数信息,这对难以获得二阶导数或者... 内点法作为一种高效的非线性规划算法,其简约空间算法实现尤其适于求解过程系统工程中的高维、低自由度优化问题,从而算法只需要在决策变量的低维空间寻求最优解,并且求解性能不依赖于模型的精确二阶导数信息,这对难以获得二阶导数或者二阶导数计算代价很大的复杂系统优化极为重要。为了保障简约空间内点法的全局收敛性,本文提出了与内点法共享空间分解结构的投影梯度可行性恢复算法。该算法结合了信赖域与线性搜索方法的优点,能够有效促进内点法的全局收敛。通过求解经典文献及CUTE/COPS算例库中的优化问题验证了本文提出算法的有效性。 展开更多
关键词 可行性恢复 内点法 简约空间方法 投影梯度
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高新技术产业知识产权证券化融资方式研究 被引量:2
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作者 宋志秀 宋俊怡 《当代经济》 2016年第34期32-35,共4页
知识产权证券化作为一种金融创新方式,在国内外得到了大量研究和尝试,它为我国高新技术产业融资开辟了新的渠道。但是在我国,知识产权证券化还存在较多障碍。本文在对知识产权证券化进行界定的基础上,着重研究知识产权证券化的风险和定... 知识产权证券化作为一种金融创新方式,在国内外得到了大量研究和尝试,它为我国高新技术产业融资开辟了新的渠道。但是在我国,知识产权证券化还存在较多障碍。本文在对知识产权证券化进行界定的基础上,着重研究知识产权证券化的风险和定价问题,创造性引入跳-扩散模型对知识产权证券化进行定价,解决产品设计中的核心问题,最后对我国知识产权证券化发展战略进行前瞻性研究。 展开更多
关键词 知识产权证券化 企业融资 跳-扩散模型 制度建设
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系统模型中线性相关矛盾方程的检测方法
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作者 王可心 邵之江 Lorenz T.Biegler 《化工学报》 EI CAS CSCD 北大核心 2013年第12期4422-4426,共5页
基于开放方程的模拟与优化能够充分体现先进的建模与优化技术在过程系统工程中的应用优势。但是由于建模错误或者优化算法本身导致的线性相关的系统模型,可能构成不相容的约束集合最终使求解失败。对这种情况提出了矛盾约束集合的检测... 基于开放方程的模拟与优化能够充分体现先进的建模与优化技术在过程系统工程中的应用优势。但是由于建模错误或者优化算法本身导致的线性相关的系统模型,可能构成不相容的约束集合最终使求解失败。对这种情况提出了矛盾约束集合的检测方法。该方法与非线性规划(NLP)算法对不可行系统的识别相结合,利用线性相关系统的结构特征,对不可行驻点处的线性系统进行分析和检测。在此过程中通过合理利用线性求解器能够显著提高矛盾约束检测的效率。基于CUTE/COPS算例构造基于线性相关不相容模型的优化问题并进行矛盾约束检测,数值结果验证了本文提出方法的有效性。 展开更多
关键词 线性相关系统 矛盾检测 可行性恢复
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AISI 304不锈钢中δ→γ相变的原位观察 被引量:23
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作者 梁高 朱丽业 +4 位作者 王成全 P.Nolli 吴建春 于艳 方园 《金属学报》 SCIE EI CAS CSCD 北大核心 2007年第2期119-124,共6页
利用共焦激光扫描显微镜原位观察了AISI304不锈钢冷却过程中高温铁素体(δ)→奥氏体(→)相变的过程及其特征.结果表明,γ相优先在δ晶界处形成;冷却速率影响γ相的生长形态,典型形态分为块状、圆形、树枝状等;“游离”γ枝晶发生粗化... 利用共焦激光扫描显微镜原位观察了AISI304不锈钢冷却过程中高温铁素体(δ)→奥氏体(→)相变的过程及其特征.结果表明,γ相优先在δ晶界处形成;冷却速率影响γ相的生长形态,典型形态分为块状、圆形、树枝状等;“游离”γ枝晶发生粗化,并和周围的γ枝晶聚合;相同冷却条件下,δ晶界处的γ枝晶聚合程度明显高于δ晶粒内部;二次枝晶在冷却过程中粗化,并竞争生长.利用ThermoCalc计算C元素在δ→γ相变过程中的偏析系数,以此求解δ→γ相变数学模型. 展开更多
关键词 AISI304不锈钢 高温铁素体 奥氏体 相变 原位观察
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空间机器人的动力学等价机械臂DEM
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作者 梁斌 李庚田 Yangsheng Xu 《控制工程(北京)》 1997年第2期1-8,共8页
本文讨论了如何将一个自由飘浮空间机器人等价成一个通常固定基座上的机器人,本文将之定义为动力学等价机械臂(DEM)方法。本文阐述了DEM方法的理论推导过程,展示了动力学与运动学的等价性,并通过仿真验证了在闭环控制下DEM与空间机器人... 本文讨论了如何将一个自由飘浮空间机器人等价成一个通常固定基座上的机器人,本文将之定义为动力学等价机械臂(DEM)方法。本文阐述了DEM方法的理论推导过程,展示了动力学与运动学的等价性,并通过仿真验证了在闭环控制下DEM与空间机器人的等价性。 展开更多
关键词 空间 机器人 动力学 变结构控制 等价机械臂
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检索矩形结构化网格中裁剪单元的数值算法 被引量:1
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作者 盖贇栋 侯文彬 +1 位作者 祝雪峰 胡平 《计算机辅助设计与图形学学报》 EI CSCD 北大核心 2019年第7期1203-1209,共7页
裁剪等几何分析的首要任务就是检索出裁剪曲面中的裁剪单元,为此提出一种快速检索矩形结构化网格中裁剪单元的数值算法.首先将网格中每个单元的边界划分为12段区间;然后在剪裁曲线上选取适当的参数点,并将得到的离散曲线代替原剪裁曲线... 裁剪等几何分析的首要任务就是检索出裁剪曲面中的裁剪单元,为此提出一种快速检索矩形结构化网格中裁剪单元的数值算法.首先将网格中每个单元的边界划分为12段区间;然后在剪裁曲线上选取适当的参数点,并将得到的离散曲线代替原剪裁曲线,对矩形结构化网格进行剪裁;根据离散剪裁曲线与单元边界交点位置的不同,将裁剪单元划分为 156 种不同的类型.该算法还可以根据不同情况来获取剪裁曲线上的点,当采用闭合逆时针矩形剪裁曲线对裁剪 NURBS 曲面参数网格进行剪裁时,该算法能够快速、有效地检索到裁剪单元,并得到剪裁曲线曲率变化大的点以及裁剪单元在物理空间中的像;悬臂梁的最优拓扑结构算例证明了该算法能够快速、有效地检索出任意矩形结构化网格中的裁剪单元. 展开更多
关键词 矩形结构化网格 裁剪NURBS曲面 剪裁曲线 裁剪单元 拓扑优化
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