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SSRN 2024年

作者： Khan, Abdul Samad Xu, He-Yong Nie, Yufeng Idrees, Muhammad Ul Samad Khan, Noor Research Center for Computational Science School of Mathematics and Statistics Northwestern Polytechnical University Xi’an710129 China National Key Laboratory of Science and Technology on Aerodynamic Design and Research Northwestern Polytechnical University Xi’an710072 China Department of Mathematics Islamia College University Peshawar25000 Pakistan Department of Computer Science City University of Science and Information Technology Peshawar25000 Pakistan

This article investigates the peristaltic heat transport for the Jeffery fluid flow over an inclined porous ciliated duct. A uniform magnetic field is considered in the momentum equation. Additionally, boussinesq approximation, Joule heating and thermal slip condition is part of temperature equation in order to enhance the heat transport distribution. Closed form exact solution of emerging differential system is attained by the program intended in the MATHEMATICA software called DSolve. The physical insight of number of parameters have been displayed graphically. It is perceived that by increasing ratio of relaxation to retardation times the favorable pressure switches to adverse pressure, which will consequently retards the flow velocity. There exists a wide array of peristaltic pumps tailored for specific settings such as laboratories, industrial contexts, chemical handling, and even tumescent procedures. These pumps showcase the versatility to effectively manage fluids spanning a spectrum of viscosities, encompassing acidic, alkaline, and sterile compositions. Peristaltic pumps have several implications, including their ability to transport a wide range of fluids. These pumps find applications in devices like infusion pumps and dialysis machines, particularly when dealing with fluids that can be corrosive or potentially harmful to the system. © 2024, The Authors. All rights reserved.

关键词： Flow velocity

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H-plane loaded and phase velocity tapered SWS for improved performance of TWT THz sources 9

H-plane loaded and phase velocity tapered SWS for improved p...

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9th IEEE UK-Europe-China Workshop on Millimetre Waves and Terahertz Technologies, UCMMT 2016

作者： Chen, Xuyuan Billa, Laxma R. Shi, Xianbao Nadeem Akram, M. Department of Micro and Nano-System Technology University College of Southeast Norway Borre Norway State Key Laboratory of Quantum Optics and Quantum Optics Devices Institute of Laser Spectroscopy Shanxi University Taiyuan Shanxi030006 China Vacuum Electronics National Laboratory School of Physical Electronics University of Electronic Science and Technology of China Chengdu610054 China

ISBN: (纸本)9781509022755

The design optimization and simulation for high performance of two types of slow wave structures (SWS) for micro-electro-mechanical system (MEMS) terahertz (THz) sources are presented, e.g., THz staggered double vane (SDV) traveling wave tube (TWT) working at center frequency of 220 GHz, H-plane and E-plane loaded (HEL) rectangular TWT working at center frequency of 400 GHz. The structures are able to realize a larger interaction impedance, thereby resulting in higher gain and improved output power of the devices. To further enhance the energy transferring between the electron beam and THz wave, the maximum length of the interaction section can be extended using the phase velocity tapering technique, where the spent electron beam energy can be reused by resynchronizing the phase velocity of the THz signal with electron velocity at the second section of the TWT. As an achievement, improved power of more than 50% is achieved over the operated bandwidth for both designs. The designs have considered the LIGA fabrication for these vacuum MEMS THz sources. © 2016 IEEE.

关键词： Electron beams

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Joint Optimization of Content Caching and Push in Renewable Energy Powered Small Cells

Joint Optimization of Content Caching and Push in Renewable ...

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Ad-Hoc and Sensor Networks Symposium

作者： Jie Gong Sheng Zhou Zhenyu Zhou Zhisheng Niu School of Data and Computer Science Sun Yat-sen University Tsinghua National Laboratory for Information Science and Technology Department of Electronic Engineering Tsinghua University State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources School of Electrical and Electronic Engineering North China Electric Power University

ISBN: (纸本)9781479966653

In this paper, we explore the content information to design the joint caching and push mechanism in the small-cell base stations (SBSs) powered by renewable energy. The problem is formulated as a Markov decision process by exploring the features of content popularity and renewal and by taking into consideration the energy consumption for both content fetch from core network and push to the users. The objective is to minimize the number of requests which cannot be met by the SBSs. We adopt the policy iteration algorithm to obtain the optimal caching and push policy. According to the numerical results, the performance gain with large SBS cache size is marginal due to the limited energy. We also find that the optimal policy reveals noticeable performance gain compared with the greedy fetch policy and the non-push policy. In addition, simulations shows the tradeoff between the number of cached contents in the SBS and the available energy for content push.

关键词： Renewable energy sources Energy consumption Unicast Optimization Energy states Batteries Resource management

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Long-distance OPGW Optical Cable Monitoring system Based on φ-OTDR technology

Long-distance OPGW Optical Cable Monitoring System Based on ...

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Asia Communications and Photonics Conference and Exhibition (ACP)

作者： Ying Wang Yanyang Lei Xing Liu Can Li Xiaomeng Xia Tong Chen Yue Deng Jing Zhang Xiaohui Tang Information Communication Dispatching Monitoring Center State Grid Information & Telecommunication Branch Beijing China National Key Laboratory of Science and Technology on Tunable Laser Harbin Institute of Technology Harbin China Energy Planning Institute Southwest Electric Power Design Institute Co. Ltd Chengdu China

In this paper, a long-range phase-sensitive optical time-domain reflectometer (φ-OTDR) system is proposed, which is based on the direct detection type φ-OTDR system, combined with the first-order forward Raman distributed amplification technology and remote pump amplification technology, to achieve 130km vibration monitoring range and 20m spatial resolution. Compared with relay EDFA amplification technology and bidirectional distributed amplification technology, the system eliminates the necessity of a remote power supply, which is of great significance in the monitoring application of long-distance OPGW optical cable.

关键词： Vibrations Stimulated emission Power supplies Optical pumping Communication cables Optical sensors Optical reflection

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Investigation of Heat Transfer and Flow Boiling Characteristics of a New Symmetric Cosine Mini-Channel Heat Exchanger with High Heat Flow Density

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SSRN 2023年

作者： Xu, Zhanying Liu, Huan-Ling Xie, Gongnan Shaanxi Key Laboratory of Space Solar Power Station System School of Electromechanical Engineering Xidian University Xi’an710071 China Key Laboratory of Electronic Equipment Structure Design Ministry of Education School of Electromechanical Engineering Xidian University Xi’an710071 China School of Marine Science and Technology Northwestern Polytechnical University Xi’an710072 China

A novel symmetric cosωx mini-channel heat exchanger (SCMC) with a combined bionic leaf vein diverter with ethanol as coolant is designed to meet the heat dissipation requirements for high heat flux chips. The mini-channel is firstly passed through a bionic leaf vein diverter to ensure the uniformity of the liquid distribution in the different mini-channels. Firstly, the homogeneity of the liquid distribution in different mini-channels is ensured by a bionic leaf vein divertor. Then, in order to obtain the flow characteristics and bubble features in the channel under conjugate conditions, a systematic three-dimensional numerical study is carried out by coupling the phase transition model with the volume of fluid (VOF) model. It is found that the symmetric distribution structure of the SCMC flow channel not only provides nucleation points for bubble generation, but also provides rupture points for large bubbles that can block the flow channel due to bubble aggregation, which reduces the instability of phase transition heat. Compared with the smooth flow channel structure of ω=1 and ω=1.5, the steep structure of ω=2 not only helps the mixing of coolant, but also increases the probability of bubbles hitting the sharp structure, which is more helpful for the rupture of large bubbles. In addition, the effects of waviness (ω ~ 0-2) and inlet velocity (Re ~ 234.07-1170.37) on the heat transfer performance under non-constant flow boiling conditions are investigated. The results show that the heat transfer capacity of SCMC increases firstly and then decreases with the increase of ω and subsequently increases again with the constant Re. The performance factor shows a decrease and then increases, which gets the maximum value at ω=2 and still shows an increasing trend. In the case of constant ω, the heat transfer capacity of SCMC is enhanced with the increase of Re, but the enhancement trend gradually slows down, and the performance factor shows a trend of increasing at first an

关键词： Heat exchangers

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Weakening s-d orbital hybridization of metallic iridium by tungsten atoms for acidic water splitting

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Applied Catalysis A: General 2023年 649卷 1页

作者： Chang, Chaofeng Xie, Yuhua Luo, Fang Zhou, Shaowei Yang, Zehui Sustainable Energy Laboratory Faculty of Materials Science and Chemistry China University of Geosciences Wuhan 388 Lumo RD Wuhan430074 China State Key Laboratory for Hubei New Textile Materials and Advanced Processing Technology School of Materials Science and Engineering Wuhan Textile University Wuhan430200 China Power system and new energy China Ship Development and Design Center Wuhan430074 China

To economically realize proton electrolyte membrane water splitting technology, stable and high-performance oxygen evolution reaction (OER) electrocatalyst is significantly demanded. In this work, we invite tungsten atoms to metallic iridium (Ir) to weaken s-d hybridization of Ir-Ir bond due to the higher electronegativity accepting electron from Ir atoms;as a result, the adsorbed O* species become electrophilic favorable for the nucleophilic attack by H2O leading to 22 % decrement in energy barrier for the formation of OOH* species. Therefore, iridium-tungsten (IrW) electrocatalyst exhibits 3.7-fold higher turnover frequency (TOF) than metallic Ir at overpotential of 370 mV in acidic OER catalysis. Moreover, stable OER performance is recorded due to the high cohesive energy of tungsten atoms. Additionally, TOF of IrW electrocatalyst reaches 10.1 s−1 at overpotential of 100 mV in acidic hydrogen evolution reaction (HER) test, 7.6-time higher than Pt/C and metallic Ir. IrW electrocatalyst only needs 1.52 V to attain 10 mA cm−2 in acidic overall water splitting. © 2022 Elsevier B.V.

关键词： Chemical bonds

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Research on fractional order controller based on best rational approximation approach

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Journal of Convergence Information technology 2012年第4期7卷 50-58页

作者： Zhao, Huimin Nie, Bing Li, Wen Deng, Wu Software Institute Dalian Jiaotong University Dalian 116028 China Key Laboratory of Numerical Simulation in the Sichuan Provincial College Neijiang Normal University Neijiang 641112 China Artificial Intelligence Key Laboratory of Sichuan Province Sichuan University of Science and Engineering Zigong 643000 China State Key Laboratory of Power Transmission Equipment and System Security and New Technology College of Electrical Engineering Chongqing University Chongqing 400044 China Key Laboratory of advanced Design and Intelligent Computing Dalian University Ministry of Education Dalian 116622 China

Introduce the basic concept of best rational approximation and constructing procedure of the best rational approximation function in Laplace domain. By an illustrative example the design method of FOC based on best rational approximation is discussed. The performance comparison of transfer functions between the FOC obtained by best rational approximation method and conventional PID shows that it is effective to apply the method in design of FOC, which can guarantee maximum absolute error of amplitude frequency characteristic of approximation function in a given error tolerance.

关键词： Rational functions

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MIC-SVM: designing a Highly Efficient Support Vector Machine for Advanced Modern Multi-core and Many-Core Architectures

MIC-SVM: Designing a Highly Efficient Support Vector Machine...

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International Symposium on Parallel and Distributed Processing (IPDPS)

作者： Yang You Shuaiwen Leon Song Haohuan Fu Andres Marquez Maryam Mehri Dehnavi Kevin Barker Kirk W. Cameron Amanda Peters Randles Guangwen Yang Tsinghua National Laboratory for Information Science and Technology (TNList) Tsinghua University Beijing China Pacific Northwest National Lab Richland WA USA Ministry of Education Key Laboratory for Earth System Modeling Tsinghua University Beijing China MIT Computer Science and Artificial Intelligence Laboratory Cambridge MA USA Virignia Tech Blacksburg VA USA Lawrence Livermore National Lab Livermore CA USA

ISBN: (纸本)9781479938018

Support Vector Machine (SVM) has been widely used in data-mining and Big Data applications as modern commercial databases start to attach an increasing importance to the analytic capabilities. In recent years, SVM was adapted to the field of High Performance Computing for power/performance prediction, auto-tuning, and runtime scheduling. However, even at the risk of losing prediction accuracy due to insufficient runtime information, researchers can only afford to apply offline model training to avoid significant runtime training overhead. Advanced multi- and many-core architectures offer massive parallelism with complex memory hierarchies which can make runtime training possible, but form a barrier to efficient parallel SVM design. To address the challenges above, we designed and implemented MIC-SVM, a highly efficient parallel SVM for x86 based multi-core and many-core architectures, such as the Intel Ivy Bridge CPUs and Intel Xeon Phi co-processor (MIC). We propose various novel analysis methods and optimization techniques to fully utilize the multilevel parallelism provided by these architectures and serve as general optimization methods for other machine learning tools. MIC-SVM achieves 4.4-84x and 18-47x speedups against the popular LIBSVM, on MIC and Ivy Bridge CPUs respectively, for several real-world data-mining datasets. Even compared with GPUSVM, run on a top of the line NVIDIA k20x GPU, the performance of our MIC-SVM is competitive. We also conduct a cross-platform performance comparison analysis, focusing on Ivy Bridge CPUs, MIC and GPUs, and provide insights on how to select the most suitable advanced architectures for specific algorithms and input data patterns.

关键词： Support vector machines Training Computer architecture Parallel processing Microwave integrated circuits Equations Bridges

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Investigations on the Two-Phase Flow and Heat Transfer Behaviors in a Central Uniform Dispersion-Type Heat Exchanger

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SSRN 2022年

作者： Guo, Qi Liu, Huan-Ling Xie, Gongnan Guo, Chao Shao, Xiao-Dong Shaanxi Key Laboratory of Space Solar Power Station System School of Electromechanical Engineering Xidian University Xi'An710071 China Key Laboratory of Electronic Equipment Structure Design Ministry of Education School of Electromechanical Engineering Xidian University Xi'An710071 China School of Marine Science and Technology Northwestern Polytechnical University Xi’an710072 China

In order to improve the temperature uniformity of multiple chips, a central uniform distributed heat exchanger (CUD) is designed. Firstly, using ethanol solution as coolant, the cooling ability of the heat exchanger is numerically investigated by using VOF gas-liquid two-phase flow model, and the two-phase flow experimental system is established to verify the correctness of the numerical results. The results verifies the accuracy of the numerical simulation method. Secondly, the two-phase flow boiling heat transfer behavior are compared with that of single-phase flow with water as coolant. The results show that with the increase of inlet flow, the thermal resistance and average temperature of two-phase flow change less than that of single-phase flow. This indicating that two-phase flow has better advantages in improving the temperature uniformity of multiple heat sources. Thirdly, the heat transfer characteristics of radiators with different Wi are studied. Finally, the prediction functions of the boiling heat transfer coefficient and pressure drop is established, and the multi-objective genetic algorithm is used to obtain the best parameters of this heat exchanger.. Furthermore, the heat dissipation of the optimized heat exchanger design is studied numerically. The simulated results are in good agreement with the optimization results. © 2022, The Authors. All rights reserved.

关键词： Two phase flow

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Joint Entity and Relation Extraction Based on Prompt Learning and Multi-channel Heterogeneous Graph Enhancement

Joint Entity and Relation Extraction Based on Prompt Learnin...

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International Symposium on Parallel and Distributed Processing with Applications, ISPA

作者： Haiqing Lv Xiaohui Han Peipei Wang Wenbo Zuo Jing Guo Lijuan Xu Key Laboratory of Computing Power Network and Information Security Ministry of Education Shandong Computer Science Center (National Supercomputer Center in Jinan) Qilu University of Technology (Shandong Academy of Sciences) Jinan China Shandong Provincial Key Laboratory of Industrial Network and Information System Security Shandong Fundamental Research Center for Computer Science Jinan China Quan Cheng Laboratory Jinan China Information Research Institute Qilu University of Technology (Shandong Academy of Sciences) Jinan China

ISBN: (数字)9798331509712

ISBN: (纸本)9798331509729

Joint extraction of entity and relation is crucial in information extraction, aiming to extract all relation triples from unstructured text. However, current joint extraction methods face two main issues. Firstly, they rarely consider the semantic information of entity and relation labels, leading to models that fail to fully understand and utilize the rich semantics in these labels, thereby limiting their performance. Secondly, although table-filling methods are widely used, they focus only on the start or end positions and ignore deep interactions between tables, relying solely on word-level information. To address these issues, we propose the P-MHE framework based on prompt learning and multi-channel heterogeneous graph enhancement. First, we use prompt templates to construct semantic nodes for entity and relation type labels, initializing them along with words as nodes in a heterogeneous graph. We iteratively fuse these semantic nodes through a message-passing mechanism to obtain node representations suitable for entity and relation extraction tasks. Secondly, we design a multi-channel heterogeneous graph to model node relationships from different perspectives, enhancing feature interactions among different types of nodes. Finally, we aggregate the semantic node information of entity and relation type labels after iteration, constructing separate decoding tables for each entity and relation type to better adapt to their respective characteristics. We evaluated our model on four public datasets. Experimental results show that P-MHE outperforms existing models on multiple public datasets. Extensive additional experiments further validate the effectiveness of our model.

关键词： Training Adaptation models Limiting Fuses Semantics Natural languages Information retrieval Feature extraction Data mining Iterative decoding

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