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Optimization-inspired manual architecture design and neural architecture search

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Science China(Information Sciences) 2023年第11期66卷 100-112页

作者： Yibo YANG zhengyang shen Huan LI Zhouchen LIN JD Explore Academy School of Mathematical Sciences Peking University Institute of Robotics and Automatic Information Systems College of Artificial Intelligence Nankai University Key Lab of General Artificial Intelligence School of Intelligence Science and Technology Peking University Institute for Artificial Intelligence Peking University Pazhou Lab

Neural architecture has been a research focus in recent years due to its importance in deciding the performance of deep networks. Representative ones include a residual network(Res Net) with skip connections and a dense network(Dense Net) with dense connections. However, a theoretical guidance for manual architecture design and neural architecture search(NAS) is still lacking. In this paper, we propose a manual architecture design framework, which is inspired by optimization algorithms. It is based on the conjecture that an optimization algorithm with a good convergence rate may imply a neural architecture with good performance. Concretely, we prove under certain conditions that forward propagation in a deep neural network is equivalent to the iterative optimization procedure of the gradient descent algorithm minimizing a cost function. Inspired by this correspondence, we derive neural architectures from fast optimization algorithms,including the heavy ball algorithm and Nesterov’s accelerated gradient descent algorithm. Surprisingly, we find that we can deem the Res Net and Dense Net as special cases of the optimization-inspired *** architectures offer not only theoretical guidance, but also good performances in image recognition on multiple datasets, including CIFAR-10, CIFAR-100, and Image Net. Moreover, we show that our method is also useful for NAS by offering a good initial search point or guiding the search space.

关键词： deep neural network manual architecture design neural architecture search image recognition optimization algorithms learning-based optimization

Newton design:designing CNNs with the family of Newton's methods

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Science China(Information Sciences) 2023年第6期66卷 122-137页

作者： zhengyang shen Yibo YANG Qi SHE Changhu WANG Jinwen MA Zhouchen LIN School of Mathematical Sciences Peking University Bytedance AI Lab JD Explore Academy Key Laboratory of Machine Perception School of Intelligence Science and TechnologyPeking University Pazhou Lab

Nowadays, convolutional neural networks(CNNs)have led the developments of machine ***, most CNN architectures are obtained by manual design, which is empirical, time-consuming, and non-transparent. In this paper, we aim at offering better insight into CNN models from the perspective of optimization theory. We propose a unified framework for understanding and designing CNN architectures with the family of Newton’s methods, which is referred to as Newton design. Specifically, we observe that the standard feedforward CNN model(PlainNet)solves an optimization problem via a kind of quasi-Newton method. Interestingly, residual network(ResNet)can also be derived if we use a more general quasi-Newton method to solve this problem. Based on the above observations, we solve this problem via a better method,the Newton-conjugate-gradient(Newton-CG)method, which inspires Newton-CGNet. In the network design,we translate binary-value terms in the optimization schemes to dropout layers, so dropout modules naturally appear in the derived CNN structures with specific locations, rather than being an empirical training *** experiments on image classification and text categorization tasks verify that Newton-CGNets perform very competitively. Particularly, Newton-CGNets surpass their counterparts ResNets by over 4% on CIFAR-10 and over 10% on CIFAR-100, respectively.

关键词： CNN dropout optimization method network design Newton's method

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基于LVDS总线的产品选型与应用方法

电子质量 2024年第4期 62-65页

作者：胡叙胜沈正阳朱习松中国电子科技集团公司第五十八研究所江苏无锡214035

随着电子设计技术的不断进步和半导体集成电路的快速发展,目前对更高的数据传输速率、更宽的宽带信道和低电压的需求与日俱增。随着低压差分信号(LVDS)在各个领域的应用越发广泛,其优势特点也越发明显。介绍了LVDS总线的优势,为LVDS元... 详细信息

随着电子设计技术的不断进步和半导体集成电路的快速发展,目前对更高的数据传输速率、更宽的宽带信道和低电压的需求与日俱增。随着低压差分信号(LVDS)在各个领域的应用越发广泛,其优势特点也越发明显。介绍了LVDS总线的优势,为LVDS元器件的选型提供了参考,使其能够更加准确地应用在不同环境中。并列举了LVDS产品常见的应用方法和注意事项,常见的应用方法主要分为直流耦合、交流耦合和多支路的应用,给实际应用中的系统设计提供了一定的参考意义。

关键词：低压差分信号产品特点产品选型应用方法

Improving surface integrity of micro-holes in ECDM using ultrahigh-speed rotary of tool cathode and non-water-based electrolyte

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Chinese Journal of Aeronautics 2024年第5期37卷 506-519页

作者： Jiwen shen Weijing KONG zhengyang XU Yongbin ZENG Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016China

The surface integrity of metal micro-hole structures produced by electrochemical discharge machining is unsatisfactory owing to the insufficient reaction area and strength of electrolysis action.A novel ultrahigh-speed Rotary Electrochemical Discharge Machining(R-ECDM)using non-water-based electrolyte is proposed to improve surface integrity by changing the breakdown medium of spark discharge and increasing the reaction area and strength of electrolysis.A mathematical model was developed to establish the relationship between rotational speed and forces acting on the *** on the magnitude of forces,controlling rotational speed changed the behavior and departure radius of bubbles on the cathode ***-speed photographs validate that,in the mathematical model,the number and departure radius of bubbles on the cathode surface gradually decrease with the increase of rotational *** experimental results show that the roughness(Ra)of the micro-hole sidewall decreases from 2.54μm to 0.20μm when the rotational speed increases from 500 r/min to 40000 r/*** length loss and wear ratio of the cathode are only 9.75μm and 6.5%,***,the micro-holes array with recast-free and surface roughness of 0.20μm is fabricated,demonstrating that the proposed approach contributes to improving surface integrity of metal micro-holes.

关键词： Electrochemical discharge machining Micro-holes Recast layer Ultrahigh-speed rotary Bubbles Force analysis Non-water-based solution

Super-resolution diffractive neural network for alloptical direction of arrival estimation beyond diffraction limits

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Light(Science & Applications) 2024年第8期13卷 1602-1614页

作者： sheng Gao Hang Chen Yichen Wang zhengyang Duan Haiou Zhang Zhi Sun Yuan shen Xing Lin Department of Electronic Engineering Tsinghua UniversityBeijing 100084China Beijing National Research Center for Information Science and Technology Tsinghua UniversityBeijing 100084China

Wireless sensing of the wave propagation direction from radio sources lays the foundation for communication,radar,navigation,***,the existing signal processing paradigm for the direction of arrival estimation requires the radio frequency electronic circuit to demodulate and sample the multichannel baseband signals followed by a complicated computing process,which places the fundamental limit on its sensing speed and energy ***,we propose the super-resolution diffractive neural networks(S-DNN)to process electromagnetic(EM)waves directly for the DOA estimation at the speed of *** multilayer meta-structures of S-DNN generate super-oscillatory angular responses in local angular regions that can perform the all-optical DOA estimation with angular resolutions beyond the diffraction *** spatial-temporal multiplexing of passive and reconfigurable S-DNNs is utilized to achieve high-resolution DOA estimation over a wide field of *** S-DNN is validated for the DOA estimation of multiple radio sources over 5 GHz frequency bandwidth with estimation latency over two to four orders of magnitude lower than the state-of-the-art commercial devices in *** results achieve the angular resolution over an order of magnitude,experimentally demonstrated with four times,higher than diffraction-limited *** also apply S-DNN’s edge computing capability,assisted by reconfigurable intelligent surfaces,for extremely low-latency integrated sensing and communication with low power *** work is a significant step towards utilizing photonic computing processors to facilitate various wireless sensing and communication tasks with advantages in both computing paradigms and performance over electronic computing.

关键词： beyond optical network

Design of bionic water jet thruster with double-chamber driven by electromagnetic force

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International Journal of Mechanical System Dynamics 2024年第3期4卷 292-302页

作者： Chong Cao Yasong Zhang Chengchun Zhang Chun shen Wen Cheng Zhenjiang Wei zhengyang Wu Luquan Ren Key Laboratory of Bionic Engineering(Ministry of Education) Jilin UniversityChangchunChina Weihai Junming Power Technology Co.Ltd. WeihaiChina

In response to the limitations of the single-chamber water jet thruster used in underwater vehicles mimicked by natural cephalopods,a novel approach involving a double-chamber water jet thruster has been *** thruster utilizes electromagnetic force to manipulate the diaphragm,thereby altering the volume of the upper and lower chambers to achieve water jet *** investigations were conducted to determine the tensile length-force characteristics of the diaphragm made of ***,key parameters of essential propulsion components,such as solenoid coils,electromagnets,and currents,were established based on the tensile length-force curve,and the propulsion capabilities of the system were evaluated through theoretical *** assessments indicate that the system does not produce reverse thrust regardless of whether the coil moves up or *** experimental results demonstrate that the maximum peak propulsion force generated by the dual-chamber water jet thruster within a 3-s cycle is 0.253N.

关键词： water jet thruster diaphragm electromagnetic force

Structural transition,electric transport,and electronic structures in the compressed trilayer nickelate La_(4)Ni_(3)O_(10)

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Science China(Physics,Mechanics & Astronomy) 2024年第11期67卷 9-15页

作者： Jingyuan Li Cui-Qun Chen Chaoxin Huang Yifeng Han Mengwu Huo Xing Huang Peiyue Ma zhengyang Qiu Junfeng Chen Xunwu Hu Lan Chen Tao Xie Bing shen Hualei Sun Dao-Xin Yao Meng Wang Center for Neutron Science and Technology Guangdong Provincial Key Laboratory of Magnetoelectric Physics and DevicesSchool of PhysicsSun Yat-sen UniversityGuangzhou 510275China Center for Materials of the Universe School of Molecular SciencesArizona State UniversityTempe 85287USA School of Sciences Sun Yat-sen UniversityShenzhen 518107China

Atomic structure and electronic band structure are fundamental properties for understanding the mechanism of superconductivity. Motivated by the discovery of pressure-induced high-temperature superconductivity at 80 K in the bilayer Ruddlesden-Popper nickelate La_(3)Ni_(2)O_(7), the atomic structure and electronic band structure of the trilayer nickelate La_(4)Ni_(3)O_(10) under pressure up to 44.3 GPa are investigated. A structural transition from the monoclinic P2_(1)/a space group to the tetragonal I4/mmm around 12.6-13.4 GPa is identified, accompanied by a drop of resistance below 7 K. Density functional theory calculations suggest that the bonding state of Ni 3d_(z^(2)) orbital rises and crosses the Fermi level at high pressures, which may give rise to possible superconductivity observed in resistance under pressure in La_(4)Ni_(3)O_(10). The trilayer nickelate La_(4)Ni_(3)O_(10) shows some similarities with the bilayer La_(3)Ni_(2)O_(7) and has unique properties, providing a new platform to investigate the underlying mechanism of superconductivity in nickelates.

关键词： La_(4)Ni_(3)O_(10) high pressure synchrotron X-ray diffraction structural transition DFT calculations

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晶体生长过程高精度温度控制系统设计

机械制造与自动化 2019年第3期48卷 220-222,228页

作者：沈正阳潘丰江南大学轻工过程先进控制教育部重点实验室

目前晶体生长装置通常采用PLC进行控制,但常规PLC的温度测量精度达不到要求的控制精度。采用PLC和高精度智能温度控制表结合,使生长槽温度精度达到±0.01℃。同时设计顺序降温控制,在规定的时间内,可进行阶段性的降温达到设定的温度。... 详细信息

目前晶体生长装置通常采用PLC进行控制,但常规PLC的温度测量精度达不到要求的控制精度。采用PLC和高精度智能温度控制表结合,使生长槽温度精度达到±0.01℃。同时设计顺序降温控制,在规定的时间内,可进行阶段性的降温达到设定的温度。该系统已在实际生产中使用,满足了高品质晶体生长的要求。

关键词：晶体生长温度控制顺序控制系统设计

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深大基坑中冠梁的变形特征及一种新型冠梁

工程地质学报 2023年第2期31卷 661-670页

作者：申正洋黄华李新生孟宏特谢冬洲长安大学地质工程与测绘学院西安710000 中国科学院武汉岩土力学研究所武汉430000

基坑尺寸影响其支护结构的变形特征,在大尺寸基坑中,长冠梁的作用并不十分明晰。为探究其受力、变形形式及对其他支护结构的影响,在前人研究基础上对大、小尺寸基坑的冠梁荷载条件及约束条件进行了研究,得出了长、短冠梁的基本变形特征... 详细信息

基坑尺寸影响其支护结构的变形特征,在大尺寸基坑中,长冠梁的作用并不十分明晰。为探究其受力、变形形式及对其他支护结构的影响,在前人研究基础上对大、小尺寸基坑的冠梁荷载条件及约束条件进行了研究,得出了长、短冠梁的基本变形特征;通过数值法验证了长冠梁的变形特性,并对冠梁完整性、锚杆预应力的设置效果等进行了评价;通过总结长冠梁支护效果的优劣点,提出了一种拼接式的新型冠梁,利用数值法对其支护效果、抗破坏扩展性进行了评价。研究表明:长冠梁比短冠梁有更完整的“波形特征”,该特征可能恶化局部排桩的稳定条件、阻碍预应力锚杆发挥作用,提出的新型冠梁通过先铰接、再刚接的方式,在减小变形、提高锚杆支护效力的基础上,保留了传统冠梁加强支护结构整体性的作用,是一种优化设计。

关键词：大型基坑长冠梁波形特征新型冠梁