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P4LoF: Scheduling Loop-Free Multi-Flow Updates in Programmable Networks
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作者 Jiqiang Xia Qi Zhan +2 位作者 Le Tian Yuxiang Hu Jianhua Peng 《Computers, Materials & Continua》 2026年第1期1236-1254,共19页
The rapid growth of distributed data-centric applications and AI workloads increases demand for low-latency,high-throughput communication,necessitating frequent and flexible updates to network routing configurations.H... The rapid growth of distributed data-centric applications and AI workloads increases demand for low-latency,high-throughput communication,necessitating frequent and flexible updates to network routing configurations.However,maintaining consistent forwarding states during these updates is challenging,particularly when rerouting multiple flows simultaneously.Existing approaches pay little attention to multi-flow update,where improper update sequences across data plane nodes may construct deadlock dependencies.Moreover,these methods typically involve excessive control-data plane interactions,incurring significant resource overhead and performance degradation.This paper presents P4LoF,an efficient loop-free update approach that enables the controller to reroute multiple flows through minimal interactions.P4LoF first utilizes a greedy-based algorithm to generate the shortest update dependency chain for the single-flow update.These chains are then dynamically merged into a dependency graph and resolved as a Shortest Common Super-sequence(SCS)problem to produce the update sequence of multi-flow update.To address deadlock dependencies in multi-flow updates,P4LoF builds a deadlock-fix forwarding model that leverages the flexible packet processing capabilities of the programmable data plane.Experimental results show that P4LoF reduces control-data plane interactions by at least 32.6%with modest overhead,while effectively guaranteeing loop-free consistency. 展开更多
关键词 Network management update consistency programmable data plane P4
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SP-Sketch:Persistent Flow Detection with Sliding Windows on Programmable Switches
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作者 Yuqian Huang Luyi Chen +1 位作者 Zilun Peng Lin Cui 《Computers, Materials & Continua》 2025年第9期6015-6034,共20页
Persistent flows are defined as network flows that persist over multiple time intervals and continue to exhibit activity over extended periods,which are critical for identifying long-term behaviors and subtle security... Persistent flows are defined as network flows that persist over multiple time intervals and continue to exhibit activity over extended periods,which are critical for identifying long-term behaviors and subtle security threats.Programmable switches provide line-rate packet processing to meet the requirements of high-speed network environments,yet they are fundamentally limited in computational and memory resources.Accurate and memoryefficient persistent flow detection on programmable switches is therefore essential.However,existing approaches often rely on fixed-window sketches or multiple sketches instances,which either suffer from insufficient temporal precision or incur substantial memory overhead,making them ineffective on programmable switches.To address these challenges,we propose SP-Sketch,an innovative sliding-window-based sketch that leverages a probabilistic update mechanism to emulate slot expiration without maintaining multiple sketch instances.This innovative design significantly reduces memory consumption while preserving high detection accuracy across multiple time intervals.We provide rigorous theoretical analyses of the estimation errors,deriving precise error bounds for the proposed method,and validate our approach through comprehensive implementations on both P4 hardware switches(with Intel Tofino ASIC)and software switches(i.e.,BMv2).Experimental evaluations using real-world traffic traces demonstrate that SP-Sketch outperforms traditional methods,improving accuracy by up to 20%over baseline sliding window approaches and enhancing recall by 5%compared to non-sliding alternatives.Furthermore,SP-Sketch achieves a significant reduction in memory utilization,reducing memory consumption by up to 65%compared to traditional methods,while maintaining a robust capability to accurately track persistent flow behavior over extended time periods. 展开更多
关键词 SKETCH persistent flow sliding window programmable switches probability subtraction
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Programmable Hierarchical Kirigami Through Controlling Local Cuts
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作者 Han Pan Peng Sun +1 位作者 Lu Dai Rui Xiao 《Acta Mechanica Solida Sinica》 2025年第5期825-833,共9页
Kirigami,through introducing cuts into a thin sheet,can greatly improve the stretchability of structures and also generate complex patterns,showing potentials in various applications.Interestingly,even with the same c... Kirigami,through introducing cuts into a thin sheet,can greatly improve the stretchability of structures and also generate complex patterns,showing potentials in various applications.Interestingly,even with the same cutting pattern,the mechanical response of kirigami metamaterials can exhibit significant differences depending on the cutting angles in respect to the loading direction.In this work,we investigate the structural deformation of kirigami metamaterials with square domains and varied cutting angles of 0°and 45°.We further introduce a second level of cutting on the basis of the first cutting pattern.By combining experiments and finite element simulations,it is found that,compared to the commonly used 0°cuts,the two-level kirigami metamaterials with 45°cuts exhibit a unique alternating arrangement phenomenon of expanded/unexpanded states in the loading process,which also results in distinct stress–strain response.Through tuning the cutting patterns of metamaterials with 45°cuts,precise control of the rotation of the kirigami unit is realized,leading to kirigami metamaterials with encryption properties.The current work demonstrates the programmability of structural deformation in hierarchical kirigami metamaterials through controlling the local cutting modes. 展开更多
关键词 Kirigami metamaterials Hierarchical cuts programmable structure Buckling instability
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Inverse Design of a NURBS-Based Chiral Metamaterial Via Machine Learning for Programmable Mechanical Deformation
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作者 Xiuhui Hou Wenhao Zhao +1 位作者 Kai Zhang Zichen Deng 《Acta Mechanica Solida Sinica》 2025年第5期739-748,共10页
Chiral metamaterials are manmade structures with extraordinary mechanical properties derived from their special geometric design instead of chemical composition.To make the mechanical deformation programmable,the non-... Chiral metamaterials are manmade structures with extraordinary mechanical properties derived from their special geometric design instead of chemical composition.To make the mechanical deformation programmable,the non-uniform rational B-spline(NURBS)curves are taken to replace the traditional ligament boundaries of the chiral structure.The Neural networks are innovatively inserted into the calculation of mechanical properties of the chiral structure instead of finite element methods to improve computational efficiency.For the problem of finding structure configuration with specified mechanical properties,such as Young’s modulus,Poisson’s ratio or deformation,an inverse design method using the Neural network-based proxy model is proposed to build the relationship between mechanical properties and geometric configuration.To satisfy some more complex deformation requirements,a non-homogeneous inverse design method is proposed and verified through simulation and experiments.Numerical and test results reveal the high computational efficiency and accuracy of the proposed method in the design of chiral metamaterials. 展开更多
关键词 Chiral metamaterials Inverse design Machine learning programmable mechanical deformation
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Body Temperature Programmable Shape Memory Thermoplastic Rubber
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作者 Taoxi Wang Zhuo Liu +5 位作者 Fu Jian Xing Shen Chen Wang Huwei Bian Tao Jiang Wei Min Huang 《Journal of Polymer Materials》 2025年第1期81-94,共14页
This paper presents the development of a thermoplastic shape memory rubber that can be programmed at human body temperature for comfortable fitting applications.We hybridized commercially available thermoplastic rubbe... This paper presents the development of a thermoplastic shape memory rubber that can be programmed at human body temperature for comfortable fitting applications.We hybridized commercially available thermoplastic rubber(TPR)used in the footwear industry with un-crosslinked polycaprolactone(PCL)to create two samples,namely TP6040 and TP7030.The shape memory behavior,elasticity,and thermo-mechanical response of these rubbers were systematically investigated.The experimental results demonstrated outstanding shape memory performance,with both samples achieving shape fixity ratios(Rf)and shape recovery ratios(R_(r))exceeding 94%.TP6040 exhibited a fitting time of 80 s at body temperature(37℃),indicating a rapid response for shape fixing.The materials also showed good elasticity before and after programming,which is crucial for comfort fitting.These findings suggest that the developed shape memory thermoplastic rubber has potential applications in personalized comfort fitting products,offering advantages over traditional customization techniques in terms of efficiency and cost-effectiveness. 展开更多
关键词 Thermoplastic rubber POLYCAPROLACTONE shape memory polymers body temperature programmable comfort fitting
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Machine learning-encoded multiscale modelling and Bayesian optimization framework to design programmable metamaterials
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作者 Yizhe Liu Xiaoyan Li +1 位作者 Yuli Chen Bin Ding 《Acta Mechanica Sinica》 2025年第1期226-245,共20页
Advanced programmable metamaterials with heterogeneous microstructures have become increasingly prevalent in scientific and engineering disciplines attributed to their tunable properties.However,exploring the structur... Advanced programmable metamaterials with heterogeneous microstructures have become increasingly prevalent in scientific and engineering disciplines attributed to their tunable properties.However,exploring the structure-property relationship in these materials,including forward prediction and inverse design,presents substantial challenges.The inhomogeneous microstructures significantly complicate traditional analytical or simulation-based approaches.Here,we establish a novel framework that integrates the machine learning(ML)-encoded multiscale computational method for forward prediction and Bayesian optimization for inverse design.Unlike prior end-to-end ML methods limited to specific problems,our framework is both load-independent and geometry-independent.This means that a single training session for a constitutive model suffices to tackle various problems directly,eliminating the need for repeated data collection or training.We demonstrate the efficacy and efficiency of this framework using metamaterials with designable elliptical holes or lattice honeycombs microstructures.Leveraging accelerated forward prediction,we can precisely customize the stiffness and shape of metamaterials under diverse loading scenarios,and extend this capability to multi-objective customization seamlessly.Moreover,we achieve topology optimization for stress alleviation at the crack tip,resulting in a significant reduction of Mises stress by up to 41.2%and yielding a theoretical interpretable pattern.This framework offers a general,efficient and precise tool for analyzing the structure-property relationships of novel metamaterials. 展开更多
关键词 Artificial neural network Multiscale computation Bayesian optimization Inverse design programmable metamaterials
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Demonstration and performance evaluation of reconfigurable multiband microwave filters using a programmable photonic integrated circuit
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作者 ASHITOSH VELAMURI KUMAR PIYUSH +6 位作者 YASH RAJ ARNAB GOSWAMI ANANDHA PADMANABHAN NITIN GHODGAONKAR DINANATH SONI JANAKIRAMAN VIRARAGHAVAN BIJOY KRISHNA DAS 《Photonics Research》 2025年第12期3341-3361,共21页
A programmable silicon photonic multiband microwave filter with tunable bandwidths has been demonstrated.The filter has been successfully used to set up a radio-over-fiber link operating in the X-band as a proof of co... A programmable silicon photonic multiband microwave filter with tunable bandwidths has been demonstrated.The filter has been successfully used to set up a radio-over-fiber link operating in the X-band as a proof of concept.For this purpose,we have investigated the programmable photonic integrated circuit comprising 14 tunable balanced Mach–Zehnder interferometers designed into a square mesh architecture and fabricated using CMOS-compatible silicon photonic technology. 展开更多
关键词 programmable silicon photonic multiband microwave filter programmable photonic integrated circuit balanced Mach Zehnder interferometers CMOS compatible silicon photonic technology square mesh architecture radio fiber link reconfigurable multiband microwave filters
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Programmable array antenna based on nematic liquid crystals for the Ka-band
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作者 WANG Qiang KE Junchen BAI Lin 《Journal of Southeast University(English Edition)》 2025年第1期78-83,共6页
A programmable low-profile array antenna based on nematic liquid crystals(NLCs)is proposed.Each antenna unit comprises a square patch radiating structure and a tunable NLC-based phase shifter capable of achieving a ph... A programmable low-profile array antenna based on nematic liquid crystals(NLCs)is proposed.Each antenna unit comprises a square patch radiating structure and a tunable NLC-based phase shifter capable of achieving a phase shift exceeding 360°with high linearity.First,the above 64 antenna units are periodically arranged into an 8×8 NLC-based antenna array,and the bias voltage of the NLC-based phase shifter loaded on the antenna unit is adjusted through the control of the field-programmable gate array(FPGA)programming sequences.This configuration enables precise phase changes for all 64 channels.Numerical simulation,sample processing,and experimental measurements of the antenna array are conducted to validate the performance of the antenna.The numerical and experimental results demonstrate that the proposed antenna performs well within the frequency range of 19.5-20.5 GHz,with a 3 dB relative bandwidth of 10%and a maximum main lobe gain of 14.1 dBi.A maximum scanning angle of±34°is achieved through the adjustment of the FPGA programming sequence.This NLC-based programmable array antenna shows promising potential for applications in satellite communication. 展开更多
关键词 array antenna nematic liquid crystals electronically beam scanning field programmable gate array(FPGA)
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中国高科技产业发展的“自然道路”及劳动者境遇
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作者 贾文娟 《浙江社会科学》 北大核心 2026年第2期41-53,156,共14页
各国的高科技产业发展与劳动者境遇,均深植于其独特的社会经济发展历史与政治经济背景,呈现本土特质。中国高科技产业在因地制宜、循序渐进的逻辑下,因循“自然道路”发展,具有包容性、均衡性、技术密集性等特征,并面对着过度使用劳动... 各国的高科技产业发展与劳动者境遇,均深植于其独特的社会经济发展历史与政治经济背景,呈现本土特质。中国高科技产业在因地制宜、循序渐进的逻辑下,因循“自然道路”发展,具有包容性、均衡性、技术密集性等特征,并面对着过度使用劳动力与产业内卷两大挑战。在这种情况下,大型数智科技企业形成了纵向一体化的“大厂”生产体制,其具有劳动强度高、优绩主义盛行、弱劳动关系化等特征,并在产业周期的不同阶段对劳动者境遇产生了迥异影响。着眼产业发展与劳动者境遇改善的良性循环,我国仍需从优化劳动法规、提升教育方式入手,对“自然道路”进行扬长补短。 展开更多
关键词 自然道路 高科技产业 程序员 生产体制
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SRv6技术在数据转发平面的应用与挑战综述
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作者 马东超 赵肖河 +2 位作者 王晨 黄思恬 马礼 《软件学报》 北大核心 2026年第1期378-397,共20页
基于IPv6的段路由(segment routing over IPv6,SRv6)作为下一代网络架构的关键使能技术,通过引入灵活的段路由转发平面,为提升网络智能化水平、拓展业务服务能力带来革新机遇.旨在全面梳理近年来SRv6的演进趋势和研究现状.首先,系统总结... 基于IPv6的段路由(segment routing over IPv6,SRv6)作为下一代网络架构的关键使能技术,通过引入灵活的段路由转发平面,为提升网络智能化水平、拓展业务服务能力带来革新机遇.旨在全面梳理近年来SRv6的演进趋势和研究现状.首先,系统总结SRv6在网络架构与性能、网络管理与运维以及新兴业务支撑等方面的应用,凸显了SRv6精细调度、灵活编程、服务融合等独特优势.与此同时,深入剖析SRv6在性能与效率、可靠性与安全性、部署与演进策略这3个方面所面临的关键挑战,并重点讨论当前主流的解决思路和发展趋势.最后,立足产业生态构建、人工智能引入、行业融合创新等视角,对SRv6未来的发展方向和挑战进行前瞻性思考和展望.研究成果将为运营商构建开放、智能、安全的新一代网络提供理论参考和实践指导. 展开更多
关键词 SRv6 软件定义网络 网络可编程 流量工程 服务功能链
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基于FPGA的低照度图像增强算法的研究与实现
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作者 肖剑 李志斌 +2 位作者 杨进 程鸿亮 胡欣 《计算机工程与科学》 北大核心 2026年第1期98-107,共10页
针对深度学习等软件方法实现低照度图像增强算法时,计算量大且复杂、实时性差等问题,实现了一种便于部署到FPGA上的基于Retinex模型的改进的低照度图像增强算法。该算法首先将输入的低照度图像进行RGB色彩空间到YCbCr色彩空间的转换,取... 针对深度学习等软件方法实现低照度图像增强算法时,计算量大且复杂、实时性差等问题,实现了一种便于部署到FPGA上的基于Retinex模型的改进的低照度图像增强算法。该算法首先将输入的低照度图像进行RGB色彩空间到YCbCr色彩空间的转换,取空间中的Y分量作为初始照度分量对其进行自适应伽玛校正和双边滤波处理,提高初始照度分量亮度的同时实现对图像的降噪和对细节的增强,接着依据Retinex模型得到增强图像。将增强后的图像再次转换到YCbCr色彩空间,对Y分量进行多尺度细节增强后转换到RGB色彩空间,作为最终的增强结果输出。实验结果表明,将在FPGA上部署所提出的低照度图像增强算法和在MATLAB上进行算法仿真后的输出图像进行比较,两者的相似度指标SSIM接近1,肉眼很难分辨出两者的差别;在时钟频率为200 MHz时,处理一幅分辨率为1280×720的图像仅需约21 ms;将所提出的算法部署在国产某型号的FPGA上时资源占用率较低,功耗为3.357 W,满足低功耗要求,具有较大的实用意义和工程应用价值。 展开更多
关键词 图像增强 FPGA 自适应伽玛校正 双边滤波 多尺度细节增强
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欧盟对中亚国家教育外交:基于政策演进的实践行动
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作者 王正青 熊彦皓 《比较教育研究》 北大核心 2026年第2期40-50,共11页
教育外交作为公共外交的形式之一,具有增进民心相通和影响青年价值观等价值。作为一体化程度最高的区域性国际组织,欧盟基于地缘政治考量,持续调整对中亚国家的教育外交政策,经历初步接触、主动参与、拓展推进和调整转型四个阶段。欧盟... 教育外交作为公共外交的形式之一,具有增进民心相通和影响青年价值观等价值。作为一体化程度最高的区域性国际组织,欧盟基于地缘政治考量,持续调整对中亚国家的教育外交政策,经历初步接触、主动参与、拓展推进和调整转型四个阶段。欧盟在实践中形成教育机构互联、业内人员互访、教学资源互享和援助项目互赢四条行动路径,推动与中亚国家的全方位合作,逐渐建立引领发展走向的统筹协商机制、确保日常运作的组织完善机制、推动政策落地的项目载体机制、夯实实施基础的资金保障机制,以及检验实践效果的质量评估机制。欧盟对中亚教育外交强化了欧盟在教育合作与价值观传播层面的影响力,为中亚青年一代提供了更多教育选择。 展开更多
关键词 欧盟 中亚国家 教育外交 欧盟价值观 伊拉斯谟+计划
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适用于轻量级客户端的多方隐私集合求交协议
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作者 杨乐 何慧阳 +2 位作者 尤玮婧 张佰韬 林璟锵 《信息网络安全》 北大核心 2026年第2期251-262,共12页
随着隐私保护需求的增长,多方隐私集合求交(MP-PSI)协议作为一种关键的隐私计算技术,在多个领域受到广泛关注。然而,在计算资源受限的环境中,现有的MP-PSI协议往往面临客户端计算负担较重的问题,限制了其在实际应用中的可行性。为解决... 随着隐私保护需求的增长,多方隐私集合求交(MP-PSI)协议作为一种关键的隐私计算技术,在多个领域受到广泛关注。然而,在计算资源受限的环境中,现有的MP-PSI协议往往面临客户端计算负担较重的问题,限制了其在实际应用中的可行性。为解决这一问题,文章提出一种基于布隆过滤器和同态加密的轻量级客户端MP-PSI协议。该协议通过引入不经意可编程伪随机函数,将大部分计算任务从客户端转移到服务器,从而显著降低了客户端的计算开销并充分利用了服务器的计算资源。实验结果表明,该协议在客户端计算时间和服务器计算效率方面均优于现有方案。协议在半诚实模型中可抵抗至多n-1个参与方合谋攻击,可确保诚实参与方的隐私。该协议为资源受限环境下的隐私保护问题提供了新的解决方案。 展开更多
关键词 多方隐私集合求交 轻量级客户端 布隆过滤器 不经意可编程伪随机函数
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一种动态精准的Flash型FPGA内核电源控制技术
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作者 马金龙 潘乐乐 +2 位作者 韦文勋 江少祥 于宗光 《半导体技术》 北大核心 2026年第3期263-269,共7页
为满足Flash型现场可编程门阵列(FPGA)在多工作模式下内核电源供电的安全性与可靠性需求,设计并实现了一种Flash型FPGA内核电源控制逻辑电路。该电路利用Flash器件的非易失特性集成状态记忆模块,精准识别FPGA的5种工作状态。通过动态控... 为满足Flash型现场可编程门阵列(FPGA)在多工作模式下内核电源供电的安全性与可靠性需求,设计并实现了一种Flash型FPGA内核电源控制逻辑电路。该电路利用Flash器件的非易失特性集成状态记忆模块,精准识别FPGA的5种工作状态。通过动态控制JD7节点电平,实现了内核电源的精准管理与电气隔离:在非用户模式下将JD7置为电源电压V_(CC),以消除信号冲突风险;在用户模式下切换为GND,建立完整的电源回路。电路在一款60万门规模的Flash型FPGA中集成验证,测试结果表明,在55~125℃范围内及±5%电源电压波动条件下,全片擦除后静态电流低至1 mA,用户模式下功能正确。本研究为高可靠Flash型FPGA提供了一种有效的内核电源管理解决方案,显著提升了芯片的鲁棒性。 展开更多
关键词 Flash型现场可编程门阵列(FPGA) 内核电源供电 电源控制电路 非易失存储 高可靠性
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一款基于新型Field Programmable Gate Array芯片的投影仪梯形校正系统研究与实现 被引量:5
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作者 曹凤莲 沈庆宏 +1 位作者 盛任农 高敦堂 《南京大学学报(自然科学版)》 CAS CSCD 北大核心 2006年第4期362-367,共6页
投影设备配备的梯形校正普遍存在校正范围小,画面的一些线条和字符边缘会出现毛刺和不平滑现象,矫正效果不理想.如果采用通用的图像处理芯片和复杂的算法,可以解决上述问题,但又会导致成本急剧上升.为了解决上述矛盾,提出一种基于FPGA(F... 投影设备配备的梯形校正普遍存在校正范围小,画面的一些线条和字符边缘会出现毛刺和不平滑现象,矫正效果不理想.如果采用通用的图像处理芯片和复杂的算法,可以解决上述问题,但又会导致成本急剧上升.为了解决上述矛盾,提出一种基于FPGA(Field Programmable Gate Array)芯片的新型梯形校正实现方案,解决了校正范围与锯齿失真的矛盾问题,并为进一步成为芯片级产品铺平了道路.图像处理采用kaiser窗函数和sinc函数相结合的方法进行插值,这样的滤波器改善了旁瓣抑制,具有较好的通带性能.介绍了梯形失真的产生和校正原理,提出了利用FPGA芯片XC3S400作为核心图像处理单元的梯形校正系统的硬件和软件实现,说明了该芯片结构、功能及特性,最后提供了校正的效果图. 展开更多
关键词 图像处理 梯形校正 FIELD programmable GATE ARRAY 锯齿失真
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基于SMART原则的“4+X”护士长综合目标考核方案的构建及应用
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作者 陈琴芬 陈敏华 +2 位作者 陈圆圆 金丽红 李晓芬 《护理实践与研究》 2026年第2期192-200,共9页
目的探讨基于SMART原则的“4+X”护士长综合目标考核方案的建立及应用效果。方法成立护士长综合目标考核领导小组,以医院发展规划、关键业绩指标法(KPI)理论为指导,遵循SMART原则制定“4+X”护士长综合目标考核标准。按照考核标准对全... 目的探讨基于SMART原则的“4+X”护士长综合目标考核方案的建立及应用效果。方法成立护士长综合目标考核领导小组,以医院发展规划、关键业绩指标法(KPI)理论为指导,遵循SMART原则制定“4+X”护士长综合目标考核标准。按照考核标准对全院49名护士长进行核心能力考核,比较实施前后护士长护理管理各维度及满意度评分。结果“4+X”护士长综合目标考核实施1年后(2023年)护理安全、护理教学科研、团队建设、岗位胜任能力、护理服务质量关键指标得分高于实施前1年(2022年),差异有统计学意义(P<0.05);“4+X”护士长综合目标考核实施1年后(2023年)医生对护士满意度、护士对工作满意度、护士对护士长满意度、上级对护士长满意度、患者对护理工作满意度得分均高于实施前,差异具有统计学意义(P<0.05)。结论由护理安全、护理教学科研、团队建设、岗位胜任力维度考核指标和护理单元护理服务质量关键指标组成的“4+X”的护士长综合考核模式更具客观性、公平性、指向性,有利于提高护士长管理水平、护理质量和护理科研能力,以防止不良事件的发生,提升患者满意度。 展开更多
关键词 SMART原则 “4+X”护士长综合目标考核方案 护理服务质量 业绩指标 岗位胜任力 护理安全
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基于PLC的伺服灌装机控制系统设计
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作者 蒋玲 邹涛 《科技创新与生产力》 2026年第1期101-105,共5页
为了满足工业生产中对灌装加工的自动化水平与高精度控制的双重需求,设计了一种高效的自动化液体灌装系统。完成了包含动作流程规划、硬件选用、电路设计、可编程逻辑控制器控制程序编写、触摸屏工程组态在内的一整套伺服灌装系统的设... 为了满足工业生产中对灌装加工的自动化水平与高精度控制的双重需求,设计了一种高效的自动化液体灌装系统。完成了包含动作流程规划、硬件选用、电路设计、可编程逻辑控制器控制程序编写、触摸屏工程组态在内的一整套伺服灌装系统的设计方案。系统采用了多轴驱动协同配合的工作模式,将伺服电机、步进电机、变频器的优势进行了整合,由可编程逻辑控制器进行控制分配,满足灌装过程对于控制精度的严格要求,同时还设计了产品检测环节,实现了智能化的分拣运输。针对生产过程中可能出现的突发状况,也规划了相应的保护机制。系统可以广泛应用于众多灌装加工行业,能够有效提高生产效率和产品质量,具有广阔的应用前景。 展开更多
关键词 灌装机 可编程逻辑控制器 步进电机 伺服电机 变频器
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A Programmable 2.4GHz CMOS Multi-Modulus Frequency Divider 被引量:1
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作者 李志强 陈立强 +1 位作者 张健 张海英 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2008年第2期224-228,共5页
A programmable multi-modulus frequency divider is designed and implemented in a 0. 35μm CMOS process. The multi-modulus frequency divider is a single chip with two dividers in series,which are divided by 4 or 5 presc... A programmable multi-modulus frequency divider is designed and implemented in a 0. 35μm CMOS process. The multi-modulus frequency divider is a single chip with two dividers in series,which are divided by 4 or 5 prescaler and by 128-255 multi-modulus frequency divider. In the circuit design, power and speed trade-offs are analyzed for the prescaler, and power optimization techniques are used according to the input frequency of each divider cell for the 128-255 multimodulus frequency divider. The chip is designed with ESD protected I/O PAD. The dividers chain can work as high as 2.4GHz with a single ended input signal and beyond 2.6GHz with differential input signals. The dual-modulus prescaler consumes 11mA of current while the 128-255 multi-modulus frequency divider consumes 17mA of current with a 3.3V power supply. The core area of the die without PAD is 0.65mm × 0.3mm. This programmable multi-modulus frequency divider can be used for 2.4GHz ISM band PLL-based frequency synthesizers. To our knowledge, this is the first reported multi-modulus frequency divider with this structure in China. 展开更多
关键词 PRESCALER frequency divider programmable multi-modulus frequency synthesizer
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基于改进YOLOv8的钢材表面缺陷检测
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作者 李昊璇 孙宇翔 《测试技术学报》 2026年第1期1-9,共9页
为应对钢材表面缺陷检测中存在的缺陷种类多元、尺寸跨度大、检测精度较低及模型泛化能力不足等挑战,提出了一种钢材表面缺陷检测改进算法,命名为CGP-YOLO。首先,在Neck部分,使用内容感知特征重组(Content-Aware Reassembly of Features... 为应对钢材表面缺陷检测中存在的缺陷种类多元、尺寸跨度大、检测精度较低及模型泛化能力不足等挑战,提出了一种钢材表面缺陷检测改进算法,命名为CGP-YOLO。首先,在Neck部分,使用内容感知特征重组(Content-Aware Reassembly of Features,CARAFE)替换最近邻插值算子,解决了上采样特征图出现的块状效应、细节丢失严重等问题;其次,在Head前引入全局注意力机制(Global Attention Mechanism,GAM),通过调控通道和空间特征的交互增强了模型的表征能力;最后,引入可编程梯度信息(Programmable Gradient Information,PGI)模块,通过其多级辅助信息组件逐步整合不同尺度的特征,有效提高了模型对不同尺度缺陷敏感性。与初始算法相比,算法CGP-YOLO性能显著提升,平均精度均值达到了80.8%,高于原算法3.6百分点。 展开更多
关键词 YOLOv8 钢材表面缺陷检测 内容感知特征重组 全局注意力机制 可编程梯度信息
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4D打印力学超材料及其在航空航天领域的应用
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作者 宋学昊 曾成均 +2 位作者 刘立武 刘彦菊 冷劲松 《航空制造技术》 北大核心 2026年第1期71-86,共16页
4D打印力学超材料作为一类具有智能响应特性的结构材料,通过可编程微观结构和多材料复合设计,实现了对力学性能的动态调控与环境适应能力。4D打印力学超材料在性能维度上展现出独特优势,但在航空航天复杂服役环境中的工程化应用仍面临... 4D打印力学超材料作为一类具有智能响应特性的结构材料,通过可编程微观结构和多材料复合设计,实现了对力学性能的动态调控与环境适应能力。4D打印力学超材料在性能维度上展现出独特优势,但在航空航天复杂服役环境中的工程化应用仍面临诸多挑战。本文梳理了4D打印力学超材料在航空航天领域的应用现状与研究进展,阐述了4D打印的基本概念、力学超材料的基本概念、4D打印力学超材料的研究进展及在航空航天领域的应用,指出当前面临的多尺度制造精度、复杂结构实现及性能稳定性等科学与技术挑战,并展望了未来在高性能智能材料开发、计算模拟与优化设计方法等方面的研究重点,揭示了4D打印力学超材料的跨学科性质。4D打印力学超材料有望推动航空航天技术向高效能、高可靠性和智能化方向发展,为相关领域的技术创新提供重要支撑。 展开更多
关键词 4D打印 力学超材料 可编程 航空航天 形状记忆聚合物
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