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Multi-dimensional tunable arbitrary shape beams with engineered axial profile

Results in Physics 2024年 59卷

作者： Lu, Zehui Guo, Meng Xu, Dongye Xiong, Lingyi Duan, Shaoxiang Yao, Yuan Zhang, Hao Lin, Wei Liu, Haifeng Liu, Bo Institute of Modern Optics College of Electronic Information and Optical Engineering Nankai University Tianjin 300350 China Southern Marine Science and Engineering Guangdong Laboratory Zhuhai 519000 China Institute of Modern Optics Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology Nankai University Tianjin 300350 China Tianjin Key Laboratory of Micro-scale Optical Information Science and Technology Nankai University Tianjin 300350 China

Bessel beams, as one type of special light field, would significantly do benefit to several applications such as light-sheet microscopy, particle manipulation and free-space optical communications. In this paper, we investigate the generation of multi-dimensional tunable arbitrary shape beams with engineered axial profile based on the superposition of zero-order Bessel beams by designing the angular spectrum, providing a universal method to manipulate arbitrary shape beams in terms of longitudinal intensity, transverse wavevector distribution and transverse field shape. Through angular spectral analysis, we demonstrate the shape-invariant axial engineering of circle, ellipse, parabolic, and epicycloid-shaped beams, as well as shape-variant axial engineering such as self-acceleration, self-rotation, and self-mode conversion, from both theoretical and experimental perspectives. Our work provides a deep insight into the fundamental properties of arbitrary shape light with engineered axial profile and paves new way toward exploiting more dimensions for its future applications. © 2024

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Bonding and Failure Mechanisms of Sintered-silver Die-attach on Electroless Nickel (Phosphorus) Surface Finish for Packaging Power Electronics Modules

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IEEE Transactions on Power Electronics 2024年

作者： Wang, Meiyu Zhang, Haobo Hu, Weibo Mei, Yunhui Lu, Guo-Quan Nankai University College of Electronic Information and Optical Engineering Tianjin300350 China Shenzhen research institute of Nankai University Shenzhen518083 China Nankai University Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology Tianjin300350 China Tiangong University School of Electrical Engineering Tianjin300387 China The Bradley Department of Electrical and Computer Engineering The Department of Materials Science and Engineering BlacksburgVA24061 United States

The low-temperature silver sintering technology has been increasingly applied for die-attach in power electronics modules. Most reported studies of the technology involved bonding on silver (Ag) or gold (Au) surface finish. Compared to Ag or Au, electroless nickel (phosphorus) or Ni(P) is a cost-effective and widely-used process for surface-finishing module substrates. However, there is a lack of studies on sintered-Ag bonding on the Ni(P) surface. In this study, IGBT devices were bonded using pressureless Ag-sintering on electroless Ni(P)-plated substrates. Micro-morphologies and macro-properties were then characterized before and after three reliability tests including high temperature storage life (HTSL), steady-state temperature-humidity bias life (STHBL), and temperature cycling (TC) tests. The as-sintered joints measured strong adhesion of 39 MPa, resulting from Ag-NiO-Ni chemical bonds across the (111) crystal planes with reduced lattice misfit. The Ag-Ni(P) joints exhibited high reliability under high-temperature and thermo-mechanical stress in the HTSL and TC tests, but performed poorly when exposed to high humidity in the STHBL test. The founding in this study helps understand the physical nature of bonding between sintered-Ag and Ni(P), and its failure mechanisms under the influence of different physical stresses. © 1986-2012 IEEE.

关键词： Bond strength (chemical)

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Towards clinical diagnosis: Automated stroke lesion segmentation on multimodal MR image using convolutional neural network

arXiv

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arXiv 2018年

作者： Liu, Zhiyang Cao, Chen Ding, Shuxue Han, Tong Wu, Hong Liu, Sheng Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology College of Electronic Information and Optical Engineering Nankai University Tianjin300071 China Key Laboratory for Cerebral Artery and Neural Degeneration of Tianjin Department of Medical Imaging Tianjin Huanhu Hospital Nankai University Tianjin300350 China School of Computer Science and Engineering University of Aizu Aizu-Wakamatsu Fukushima965-8580 Japan School of Basic Medical Sciences Tianjin Medical University Tianjin300071 China

The patient with ischemic stroke can benefit most from the earliest possible definitive diagnosis. While the high quality medical resources are quite scarce across the globe, an automated diagnostic tool is expected in analyzing the magnetic resonance (MR) images to provide reference in clinical diagnosis. In this paper, we propose a deep learning method to automatically segment ischemic stroke lesions from multi-modal MR images. By using atrous convolution and global convolution network, our proposed residual-structured fully convolutional network (Res-FCN) is able to capture features from large receptive fields. The network architecture is validated on a large dataset of 212 clinically acquired multi-modal MR images, which is shown to achieve a mean dice coefficient of 0.645 with a mean number of false negative lesions of 1.515. The false negatives can reach a value that close to a common medical image doctor, making it exceptive for a real clinical application. Copyright © 2018, The Authors. All rights reserved.

关键词： Magnetic resonance imaging

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Highly Directional Aerosol Fluorescence Emission Excited by Femtosecond Laser Filament

SSRN

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SSRN 2022年

作者： Xue, Jiayun Zeng, Xi Guo, Lanjun Guo, Rui Zhang, Zhi Chu, Chunyue Cheng, Zhenzhou Zhang, Nan Lin, Lie Liu, Weiwei Institute of Modern Optics Eye Institute Nankai University Tianjin300350 China School of Medical Devices Shanghai University of Medicine and Health Sciences Shanghai201318 China Shanghai University of Medicine and Health Sciences China Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology Tianjin300350 China School of Economics and Management Qilu Normal University Shandong Jinan250013 China

Backward angular distributions of the sodium fluorescence in NaCl aerosols induced by femtosecond laser filamentation in air with a distance of 10 m are measured. The recorded signals appear as strong angular dependence. Further study indicates that it could be associated with the Mie scattering of the filamentation-induced "aerosol lasing" in the forward direction. These results will benefit the remote-sensing of air pollutants by femtosecond laser filamentation-based LIDAR (light detection and ranging). © 2022, The Authors. All rights reserved.

关键词： Remote sensing

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Fitting Curves with Fractional Implicit Polynomials: A PSO-Assisted Monomial Combination Optimization Framework

Fitting Curves with Fractional Implicit Polynomials: A PSO-A...

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Artificial Intelligence technology (ACAIT), Asian Conference on

作者： Yuerong Tong Lina Yu Weijun Li Jingyi Liu Luyang Hou Linjun Sun Min Wu AnnLab Institute of Semiconductors Chinese Academy of Sciences Beijing China School of Materials Science and Optoelectronic Technology & School of Integrated Circuits University of Chinese Academy of Sciences Beijing China Beijing Key Laboratory of Semiconductor Neural Network Intelligent Sensing and Computing Technology Beijing China Beijing University of Posts and Telecommunications Beijing China

ISBN: (数字)9798350359145

ISBN: (纸本)9798350359152

Implicit polynomial can efficiently represent the object contour for the curve fitting, and fractional implicit polynomial (FIP) is capable of describing complex objects at lower degree. However, both of IP and FIP based curve fitting methods suffer from the problem of insufficient fitting accuracy because of spurious zero sets. In this paper, we propose a particle swarm optimization (PSO)-assisted monomial combination optimization framework to fit curves based on FIP. In the proposed PSO-FIP framework, we adopt a monomial combination optimization strategy to remove redundant monomials and reduce spurious zero sets accordingly. And then, we solve the combinatorial explosion problem by using PSO in the monomial combination optimization. We further propose a geometric distance metric to serve as the fitness function in PSO which overcomes the trivial solution problem of algebraic distance. We conduct extensive experiments to validate the PSO-FIP framework and the results demonstrate that our approach can achieve higher accuracy with fewer coefficients in curve fitting.

关键词： Measurement Fitting Noise Interference Polynomials Surface fitting IP networks

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Resource allocation for wireless cooperative relaying networks with network coding

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Ruan Jian Xue Bao/Journal of Software 2013年第SUPPL.1期24卷 76-87页

作者： Ma, Xiao-Lin F.-M., Li X.-H., Liu School of Information Engineering Wuhan University of Technology Wuhan 430070 China Key Laboratory of Fiber Optical Sensing Technology and Information Processing Ministry of Education Wuhan 430070 China Hubei Key Laboratory of Broadband Wireless Communication and Sensor Network Wuhan 430070 China

This paper surveys the state-of-the-art researches of wireless cooperative relaying networks with network coding, investigates representative resource allocation strategies, and analyzes their features, performance and system requirements. It then discusses the effects of network coding, including digital network coding and physical network coding, in the design of resource allocation strategies for wireless cooperative relaying networks. As a result, a pragmatic system-level cross-layer optimization framework and associated core design principles are suggested. Finally, the future work of resource allocation for wireless cooperative relaying networks is presented, and some essential problems to be solved for final practical proposals are also addressed. © 2013 ISCAS.

关键词： network coding

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Distributed Resource Allocation and Computation Offloading Based on Blockchain in Vehicle Edge Computing

Distributed Resource Allocation and Computation Offloading B...

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Future Communications and networks (FCN), International Conference on

作者： Xiaoting Ruan Fei Shen Feng Yan Lianfeng Shen Yi Wu Liang Tang Yu Zhao Zhiyong Bu Key Laboratory of Wireless Sensor Network and Communications Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai China University of Chinese Academy of Sciences Beijing China Shanghai Spacecom Satellite Technology Ltd Shanghai China National Mobile Communications Research Laboratory Southeast University Nanjing China Fujian Provincial Engineering Technology Research Center of Photoelectric Sensing Application Fujian Normal University Fuzhou China

ISBN: (数字)9798331512880

ISBN: (纸本)9798331512897

Mobile edge computing (MEC) extends cloud computing capabilities to the network edge, enabling efficient processing of compute-intensive tasks from resource-constrained devices. However, static edge servers can lead to service vulnerabilities due to dynamic user device locations. This paper introduces a vehicle edge computing (VEC) architecture, leveraging vehicles’ idle computing resources to serve as mobile edge servers for nearby vehicles. As the number of vehicles and compute-intensive tasks increases, substantial data exchanges between vehicles and edge servers raise significant security risks in VEC networks lacking security measures. To address the security challenges and manage computing resources, we integrate VEC with blockchain technology, creating a secure offloading framework. Focusing on video task offloading generated by vehicle applications, we propose a resource allocation scheme that comprehensively considers video compression, offloading decisions, bandwidth, and computational resource constraints. This scheme is formulated as a mixed, discrete, non-convex joint optimization problem aimed at maximizing system revenue. Since this type of problem is usually an NP-hard problem, discrete variable relaxation and product term replacement are applied to transform it into a convex optimization problem, and an alternating direction method of multipliers-based distributed resource allocation (ADMM-DRA) algorithm is proposed to solve it. Simulation experiments show that compared with other algorithms, ADMM-DRA can achieve the highest system revenue, effectively reduce system latency, and improve resource utilization.

关键词： Multi-access edge computing Transforms Video compression Convex functions Blockchains Resource management Servers Security Vehicle dynamics Optimization

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From Universe to Metaverse: IRS-Assisted Efficient Transmission for Hybrid Earth-Moon network

From Universe to Metaverse: IRS-Assisted Efficient Transmiss...

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IEEE Conference on Vehicular technology (VTC)

作者： Chengcheng Lv Fei Shen Feng Yan Lianfeng Shen Yi Wu Liang Tang Yu Zhao Zhiyong Bu Key Laboratory of Wireless Sensor Network and Communications Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai China University of Chinese Academy of Sciences Beijing China National Mobile Communications Research Laboratory Southeast University Nanjing China Fujian Provincial Engineering Technology Research Center of Photoelectric Sensing Application Fujian Normal University Fuzhou China Shanghai Spacecom Satellite Technology Ltd. Shanghai China

ISBN: (数字)9798331517786

ISBN: (纸本)9798331517793

To fulfill the requirements of human lunar exploration programs and establish bases on the moon in the distant future, lunar sensors (LSs) will inevitably produce a significant amount of data. It is necessary to construct the Earth-Moon metaverse in order to obtain and utilize lunar information more effectively. Due to the long communication distance between Earth and Moon as well as the lack of communication resources, a hybrid Earth-Moon metaverse network with channel model and transmission model is designed. To ensure the efficiency and stability of transmission in the network, LSs transmit lunar data to Earth clients (ECs) through the active and passive intelligent reflecting surface (IRS) deployed at relay satellites. Then, we propose a Stackelberg game model to describe the adversarial relationship between the satellites, LSs and ECs, and optimal strategies are obtained by solving the Nash equilibrium to maximize their utility. Simulations demonstrate that the network can effectively shorten the transmission delay and improve the utility of ECs and satellites.

关键词： Earth Vehicular and wireless technologies Metaverse Moon Games Nash equilibrium Vectors Delays Channel models Optimization

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In-Situ and Ultrasensitive Detection of Mercury (Ii) Ions (Hg2+) Using the Localized Surface Plasmon Resonance (Lspr) Nanosensor and the Microfluidic Chip

SSRN

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SSRN 2022年

作者： Zhang, Wenjia Liu, Guohua Bi, Jinqiang Bao, Kexin Wang, Peiren Tianjin Research Institute of Water Transport Engineering M.O.T. Tianjin300456 China National Engineering Research Center of Port Hydraulic Construction Technoloy Tianjin300456 China College of Microelectronics Nankai University Tianjin300350 China Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology Tianjin300350 China Engineering Research Center of thin film optoelectronics technology Ministry of Education Nankai University Tianjin300350 China School of Marine Science and Technology Tianjin University Tianjin300192 China

Mercury is one of the most dangerous heavy metals due to its extreme toxicity to both humans and the biosphere. In this work, an in-situ and ultrasensitive method for the detection of mercury (II) ions (Hg 2+ ) using the dark-field microspectroscopy-based localized surface plasmon resonance (LSPR) nanosensor is demonstrated. In our homemade high-throughput microfluidic chip, the fixed nanorods and the free small gold nanospheres combine to form the core-satellite structures with the help of T- Hg 2+ -T chemical coordination. Such a process results in a spectral red shift due to plasmonic coupling, which allows us to reach a picomolar detection limit and a linear response range from 10 pM to 10 µM. In addition, our LSPR nanosensor has excellent selectivity and no interference for the detection of Hg 2+ , which was evaluated by monitoring responses to different heavy metal ions (Pb 2+ , Cd 2+ , Cr 2+ , Ni 2+ , and Cu 2+ ) and their mixed samples. Our sensor platform's effectiveness offers a practical method for detecting traces of Hg 2+ in real-life water samples. © 2022, The Authors. All rights reserved.

关键词： Microfluidic chips

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Automated Segmentation of Brain Gray Matter Nuclei on Quantitative Susceptibility Mapping Using Deep Convolutional Neural network

arXiv

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arXiv 2020年

作者： Chai, Chao Qiao, Pengchong Zhao, Bin Wang, Huiying Liu, Guohua Wu, Hong Haacke, E. Mark Shen, Wen Cao, Chen Ye, Xinchen Liu, Zhiyang Xia, Shuang Department of Medical Imaging Tianjin First Central Hospital Tianjin300192 China Tianjin Medical Imaging Institute Tianjin300192 China Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology College of Electronic Information and Optical Engineering Nankai University Tianjin300350 China Department of Radiology Wayne State University DetroitMI48202 United States Department of Medical Imaging Tianjin Huanhu Hospital Tianjin300350 China DUT-RU International School of Information Science and Engineering Dalian University of Technology Dalian116620 China

Abnormal iron accumulation in the brain subcortical nuclei has been reported to be correlated to various neurodegenerative diseases, which can be measured through the magnetic susceptibility from the quantitative susceptibility mapping (QSM). To quantitively measure the magnetic susceptibility, the nuclei should be accurately segmented, which is a tedious task for clinicians. In this paper, we proposed a double-branch residual-structured U-Net (DB-ResUNet) based on 3D convolutional neural network (CNN) to automatically segment such brain gray matter nuclei. To better tradeoff between segmentation accuracy and the memory efficiency, the proposed DB-ResUNet fed image patches with high resolution and the patches with low resolution but larger field of view into the local and global branches, respectively. Experimental results revealed that by jointly using QSM and T1 weighted imaging (T1WI) as inputs, the proposed method was able to achieve better segmentation accuracy over its single-branch counterpart, as well as the conventional atlas-based method and the classical 3D-UNet structure. The susceptibility values and the volumes were also measured, which indicated that the measurements from the proposed DB-ResUNet are able to present high correlation with values from the manually annotated regions of interest. Copyright © 2020, The Authors. All rights reserved.

关键词： Magnetic susceptibility

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