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Dynamic access task scheduling of LEO constellation based on space-based distributed computing

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Journal of Systems Engineering and Electronics 2024年第4期35卷 842-854页

作者： LIU Wei JIN Yifeng ZHANG Lei gao zihe TAO Ying Institute of Telecommunication and Navigation Satellites China Academy of Space TechnologyBeijing 100094China Innovation Center of Satellite Communication System China National Space AdministrationBeijing 100094China

A dynamic multi-beam resource allocation algorithm for large low Earth orbit(LEO)constellation based on on-board distributed computing is proposed in this *** allocation is a combinatorial optimization process under a series of complex constraints,which is important for enhancing the matching between resources and requirements.A complex algorithm is not available because that the LEO on-board resources is *** proposed genetic algorithm(GA)based on two-dimen-sional individual model and uncorrelated single paternal inheri-tance method is designed to support distributed computation to enhance the feasibility of on-board application.A distributed system composed of eight embedded devices is built to verify the algorithm.A typical scenario is built in the system to evalu-ate the resource allocation process,algorithm mathematical model,trigger strategy,and distributed computation *** to the simulation and measurement results,the proposed algorithm can provide an allocation result for more than 1500 tasks in 14 s and the success rate is more than 91%in a typical *** response time is decreased by 40%com-pared with the conditional GA.

关键词： beam resource allocation distributed computing low Earth obbit(LEO)constellation spacecraft access task scheduling

Ultrafast control of fractional orbital angular momentum of microlaser emissions

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Light(Science & Applications) 2020年第1期9卷 286-294页

作者： Zhifeng Zhang Haoqi Zhao Danilo Gomes Pires Xingdu Qiao zihe gao Josep *** Stefano Longhi Natalia M.Litchinitser Liang Feng Department of Electrical and Systems Engineering University of PennsylvaniaPhiladelphiaPA 19104USA Department of Electrical and Computer Engineering Duke UniversityDurhamNC 27708USA Department of Materials Science and Engineering University of PennsylvaniaPhiladelphiaPA 19104USA Department of Electrical and Computer Engineering Northeastern UniversityBostonMA 02115USA Dipartimento di Fisica Politecnico di Milano and Istituto di Fotonica e Nanotecnologie del Consiglio Nazionale delle RicerchePiazza L.da Vinci 32I-20133 MilanoItaly Instituto de Fisica Interdisciplinar y Sistemas Complejos IFISC(CSIC-UIB) Palma de MallorcaSpain

On-chip integrated laser sources of structured light carrying fractional orbital angular momentum(FOAM)are highly desirable for the forefront development of optical communication and quantum information-processing *** integrated vortex beam generators have been previously demonstrated in different optical settings,ultrafast control and sweep of FOAM light with low-power control,suitable for high-speed optical communication and computing,remains *** we demonstrate fast control of the FOAM from a vortex semiconductor microlaser based on fast transient mixing of integer laser vorticities induced by a control pulse.A continuous FOAM sweep between charge 0 and charge+2 is demonstrated in a 100 ps time window,with the ultimate speed limit being established by the carrier recombination time in the gain *** results provide a new route to generating vortex microlasers carrying FOAM that are switchable at GHz frequencies by an ultrafast control pulse.

关键词： momentum fractional vortex

The PI3K/Akt/GSK-3β/ROS/eIF2B pathway promotes breast cancer growth and metastasis via suppression of NK cell cytotoxicity and tumor cell susceptibility

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Cancer Biology & Medicine 2019年第1期16卷 38-54页

作者： Fengjiao Jin Zhaozhen Wu Xiao Hu Jiahui Zhang zihe gao Xiao Han Junfang Qin Chen Li Yue Wang School of Medicine Nankai University Institute of Biomedical Engineering Chinese Academy of Medical Sciences & Peking Union Medical College State Key Laboratory of Medicinal Chemical Biology Nankai University

Objective: To examine the effect of pSer9-GSK-3β on breast cancer and to determine whether the underlying metabolic and immunological mechanism is associated with ROS/eIF2B and natural killer(NK) ***: We employed TWS119 to inactivate GSK-3β by phosphorylating Ser9 and explored its effect on breast cancer and NK cells. The expression of GSK-3β, natural killer group 2 member D(NKG2D) ligands, eIF2B was quantified by PCR and Western blot. We measured intracellular reactive oxygen species(ROS) and mitochondrial ROS using DCFH-DA and MitoSOX^(TM) probe,respectively, and conducted quantitative analysis of cellular respiration on 4T1 cells with mitochondrial respiratory chain complex Ⅰ/Ⅲ ***: Our investigation revealed that TWS119 downregulated NKG2D ligands(H60 a and Rae1), suppressed the cytotoxicity of NK cells, and promoted the migration of 4T1 murine breast cancer cells. Nevertheless, LY290042, which attenuates p-GSK-3β formation by inhibiting the PI3K/Akt pathway, reversed these effects. We also found that higher expression of p Ser9-GSK-3β induced higher levels of ROS, and observed that abnormality of mitochondrial respiratory chain complex Ⅰ/Ⅲ function induced the dysfunction of GSK-3β-induced electron transport chain, naturally disturbing the ROS level. In addition, the expression of NOX3 and NOX4 was significantly up-regulated, which affected the generation of ROS and associated with the metastasis of breast cancer. Furthermore, we found that the expression of pSer535-eIF2B promoted the expression of NKG2D ligands(Mult-1 and Rae1) following by expression of pSer9-GSK-3β and generation of ***: The PI3K/Akt/GSK-3β/ROS/eIF2B pathway could regulate NK cell activity and sensitivity of tumor cells to NK cells,which resulted in breast cancer growth and lung metastasis. Thus, GSK-3β is a promising target of anti-tumor therapy.

关键词： GSK-3β NK cells NKG2D/NKG2DLs ROS eIF2B breast cancer

An Experimental-Based Model for Prediction of the Rock Mass-Related TBM Utilization by Adopting the RMR and Moisture-Dependent CAI

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Journal of Earth Science 2023年

作者： Changbin Yan Ziang gao Gongbiao Yang zihe gao Lei Huang Jihua Yang School of Civil Engineering Zhengzhou University China Railway Construction Underwater Tunnel Engineering Laboratory Three Gorges Research Center for Geohazards Ministry of Education China University of Geosciences Yellow River Engineering Consulting Co. Ltd.

To reduce the uncertainty associated with the traditional definition of tunnel boring machine(TBM) utilization(U) and achieve an effective indicator of TBM performance, a new performance indicator called rock mass-related utilization(Ur) is introduced; this variable considers only rock mass-related factors rather than all potential factors. This work aims to predict Urby adopting the rock mass rating(RMR) and the moisture-dependent Cerchar abrasivity index(CAI). Substantial Ur, RMR and CAI data are acquired from a 31.57 km northwestern Chinese water conveyance tunnel via tunnelling field recordings, geological investigations and Cerchar abrasivity tests. The moisture dependence of the CAI is explored across four lithologies: quartz schists, granites, sandstones and metamorphic andesites. The potential influences of RMR and CAI on Urare then investigated. As the RMR increases, Urinitially increases and then peaks at an RMR of 56 before declining. Urappears to decline with CAI. An investigation-based relation among Ur, RMR and moisture-dependent CAI is developed for estimating Ur. The developed relation can accurately predict Urusing RMR and moisturedependent CAI in the majority of the tunnelling cases examined. This work proposes a stable indicator of TBM performance and provided a fairly accurate prediction method for this indicator.

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DDoS Attack Detection Method for Space-Based Network Based on SDN Architecture

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ZTE Communications 2020年第4期18卷 18-25页

作者： JIA Min SHU Yuejie GUO Qing gao zihe XIE Suofei Communication Research Center School of Electronics and Information EngineeringHarbin Institute of TechnologyHarbin 150006China Institute of Telecommunication Satellite China Academy of Space TechnologyBeijing 100094China

With the development of satellite communications,the number of satellite nodes is constantly increasing,which undoubtedly increases the difficulty of maintaining network *** software defined network(SDN) with traditional space-based networks provides a new class of ideas for solving this ***,because of the highly centralized network management of the SDN controller,once the SDN controller is destroyed by network attacks,the network it manages will be paralyzed due to loss of *** of the main security threats to SDN controllers is Distributed Denial of Service(DDoS) attacks,so how to detect DDoS attacks scientifically has become a hot topic among SDN security *** paper proposes a DDoS attack detection method for space-based networks based on SDN *** attack detection method combines the optimized Long Short-Term Memory(LSTM) deep learning model and Support Vector Machine(SVM),which can not only make classification judgments on the time series,but also achieve the purpose of detecting and judging through the flow characteristics of a period of *** addition,it can reduce the detection time as well as the system burden.

关键词： space-based network SDN DDoS attack LSTM SVM

Broadband continuous supersymmetric transformation:a new paradigm for transformation optics

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eLight 2022年第1期2卷 203-212页

作者： Jieun Yim Nitish Chandra Xilin Feng zihe gao Shuang Wu Tianwei Wu Haoqi Zhao Natalia M.Litchinitser Liang Feng Department of Materials Science and Engineering University of PennsylvaniaPhiladelphiaPA 19104USA Department of Electrical and Computer Engineering Duke UniversityDurhamNC 27708USA Department of Electrical and Systems Engineering University of PennsylvaniaPhiladelphiaPA 19104USA.

Transformation optics has formulated a versatile framework to mold the flow of light and tailor its spatial characteristics at *** its huge success in bringing scientific fiction(such as invisibility cloaking)into reality,the coordinate transformation often yields extreme material parameters unfeasible even with ***,we demonstrate a new transformation paradigm based upon the invariance of the eigenspectra of the Hamiltonian of a physical system,enabled by *** creating a gradient-index metamaterial to control the local index variation in a family of isospectral optical potentials,we demonstrate broadband continuous supersymmetric transformation in optics,on a silicon chip,to simultaneously transform the transverse spatial characteristics of multiple optical states for arbitrary steering and switching of light *** a novel synergy of symmetry physics and metamaterials,our work provides an adaptable strategy to conveniently tame the flow of light with full exploitation of its spatial degree of freedom.

关键词： Supersymmetry Transformation optics Metamaterials Integrated photonics

应用动态感知的卫星分布式集群管理平台设计与实现

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航天器工程 2024年第2期33卷 125-132页

作者：高曌高杨高梓贺陶滢中国空间技术研究院通信与导航卫星总体部北京100094 北京空间飞行器总体设计部北京100094

卫星互联网环境中存在卫星节点资源受限、链路拓扑高动态变化和网络传输高时延等问题。针对上述问题导致的卫星节点资源利用率低、系统服务响应能力较弱、负载不均衡,提出利用容器编排技术整合卫星节点资源的卫星分布式集群管理平台构... 详细信息

卫星互联网环境中存在卫星节点资源受限、链路拓扑高动态变化和网络传输高时延等问题。针对上述问题导致的卫星节点资源利用率低、系统服务响应能力较弱、负载不均衡,提出利用容器编排技术整合卫星节点资源的卫星分布式集群管理平台构建方案。其中,重点针对Kubernetes默认资源编排调度策略无法适用于卫星互联网复杂链路环境的问题,设计一种应用动态感知的卫星分布式集群资源调度方法,通过分布式集群资源状态实时感知模块,采集卫星节点CPU、内存、磁盘及网络资源的负载情况作为评价指标,完成卫星互联网环境下不同应用Pod资源对象的优化调度。仿真结果表明:应用动态感知调度方法构建的卫星分布式集群管理平台,可以实现卫星网络环境下系统资源的合理调度,提升系统负载均衡能力,进而保证系统服务的快速响应。

关键词：卫星分布式集群资源调度容器编排技术负载均衡仿真验证

纵向通风对隧道火灾特性及竖井自然排烟效果的影响

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郑州大学学报（工学版） 2020年第6期41卷 46-52页

作者：钟委刘欣高子鹤郑州大学力学与安全工程学院河南郑州450001 郑州大学土木工程学院河南郑州450001

采用1∶10小尺寸隧道模型,研究了采用竖井自然排烟的隧道内,纵向通风对隧道内火焰形态、质量损失速率及竖井内温度分布和排烟速度的影响。结果表明:随着竖井高度和纵向风速的改变,在纵向通风和烟囱效应诱发气流的耦合作用下,隧道内火焰... 详细信息

采用1∶10小尺寸隧道模型,研究了采用竖井自然排烟的隧道内,纵向通风对隧道内火焰形态、质量损失速率及竖井内温度分布和排烟速度的影响。结果表明:随着竖井高度和纵向风速的改变,在纵向通风和烟囱效应诱发气流的耦合作用下,隧道内火焰向下游倾斜,造成燃料质量损失速率发生变化,进而影响隧道内的烟气输运规律,并最终影响竖井排烟的温度分布和排烟速度。当排烟口下方的烟气层发生吸穿时,竖井内部出现低温区,此时隧道下部的冷空气直接通过竖井排出,大大减弱了竖井的排烟效果,在对烟气层吸穿现象进行分析的基础上,对Hinckley提出的临界吸穿Froude数进行了修正,得到了用于判断纵向通风条件下竖井自然排烟吸穿的临界Froude数为3.2,当Froude数介于3.2~5.1时,竖井排烟处于吸穿区,Froude数介于0.6~3.2时,处于未吸穿区,且Froude数随着竖井的升高而逐渐增大。

关键词：隧道纵向风竖井吸穿 Froude数

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直立式机械排烟临界排烟口高度

安全与环境学报 2024年第5期24卷 1849-1854页

作者：钟委吴英昊田英高子鹤郑州大学力学与安全工程学院郑州450001 郑州大学土木工程学院郑州450001

为改善地铁站台的排烟效果,提出了一种在排烟管道顶部上接风管的新型直立式机械排烟。通过数值模拟分析地铁站台火灾时采用直立式机械排烟的效果。结果表明:采用上接风管的直立式排烟相比于排烟管道顶面排烟具有明显优势,其排热量可增加... 详细信息

为改善地铁站台的排烟效果,提出了一种在排烟管道顶部上接风管的新型直立式机械排烟。通过数值模拟分析地铁站台火灾时采用直立式机械排烟的效果。结果表明:采用上接风管的直立式排烟相比于排烟管道顶面排烟具有明显优势,其排热量可增加14.51%;直立式排烟存在一个临界排烟口高度,当排烟口高度较低时无法排出顶棚下方的高温烟气,而当排烟口高度超过该临界高度后,受到顶棚的限制其排烟效果反而会下降;临界排烟口高度与排烟风速无关,但受排烟口边长的影响,且在临界高度时排烟口与顶棚间的距离近似等于排烟口边长的一半。

关键词：安全工程地铁站台直立式机械排烟临界高度排烟口尺寸