检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

无线Mesh网络链路非相关多径发现算法

计算机研究与发展 2007年第10期44卷 1751-1756页

作者：丁旭阳范明钰罗惠琼电子科技大学计算机科学与工程学院成都610054

非相关路径的使用对于提高网络性能有极其重要的作用,但当前无线Mesh网络的路由协议都不支持链路非相关多径的寻找.在分析DSR协议不足的基础上,提出了一种基于DSR改进的链路非相关多径寻找算法EDSR(enhancedDSR).其核心思想是在DSR路由... 详细信息

非相关路径的使用对于提高网络性能有极其重要的作用,但当前无线Mesh网络的路由协议都不支持链路非相关多径的寻找.在分析DSR协议不足的基础上,提出了一种基于DSR改进的链路非相关多径寻找算法EDSR(enhancedDSR).其核心思想是在DSR路由寻找完成后,利用网络节点的路由缓存发现和寻找源节点与目的节点间的链路非相关路径.通过非相关路径的使用,提高网络吞吐率,从而达到提高网络性能的目的.仿真结果表明,EDSR算法能以较少的代价获取非相关路径,提高网络性能.

关键词：无线Mesh网络 DSR EDSR 链路非相关多径

一种基于 RNN 区分 DDoS 攻击类型的方法

在线全文

学校读者我要写书评

暂无评论

信息网络安全 2022年第7期22卷 1-8页

作者：范明钰李珂电子科技大学计算机科学与工程学院成都611731 重庆大学土木工程学院重庆400044

随着网络技术的广泛应用,出现了多种多样的网络攻击,其中,分布式拒绝服务(Distributed Denial of Service,DDoS)攻击的危害性较大。将12种DDoS攻击的数据与正常数据流混在一起后难以区分,因此防御DDoS攻击的关键是对其进行有效区分。文... 详细信息

随着网络技术的广泛应用,出现了多种多样的网络攻击,其中,分布式拒绝服务(Distributed Denial of Service,DDoS)攻击的危害性较大。将12种DDoS攻击的数据与正常数据流混在一起后难以区分,因此防御DDoS攻击的关键是对其进行有效区分。文章提出一种基于RNN区分DDoS攻击类型的方法。以循环神经网络(Recurrent Neural Network,RNN)为研究改进对象,运用了模型的模块化研究方法和技术,抽象出3类简单模块组合形成RNN-IDDoS模型,该模型具有5层、3种时间步。在公开数据集上进行实验,实验结果表明该模型的准确率可达99.8%,优于当前其他3种模型,取得了很好的区分效果。

关键词： DDoS攻击类型区分 RNN

Complete Universal Scaling in First-Order Phase Transitions

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2024年第10期41卷 8-13页

作者： fan Zhong School of Physics and State Key Laboratory of Optoelectronic Materials and Technologies Sun Yat-sen UniversityGuangzhou 510275China

Phase transitions and critical phenomena are among the most intriguing phenomena in nature and *** are classified into first-order phase transitions(FOPTs)and continuous *** the latter shows marvelous phenomena of scaling and universality,whether the former behaves similarly is a long-standing controversial *** we definitely demonstrate complete universal scaling in field driven FOPTs for Langevin equations in both zero and two spatial dimensions by rescaling all parameters and subtracting nonuniversal contributions with singular dimensions from an effective temperature and a special field according to an effective *** offers a perspective different from the usual nucleation and growth but conforming to continuous phase transitions to study FOPTs.

关键词： theory. transitions scaling

Semi-analytical Solutions for Wellbores with Graded Skin Zones in Poroelastic Media

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2024年第3期37卷 385-395页

作者： Zhiqiang fan Zhihe Jin School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi’an710072China Department of Mechanical Engineering University of MaineOronoME04469USA

In analyzing the complex interaction between the wellbore and the reservoir formation,the hydromechanical properties of the region proximal to the wellbore,referred to as the“wellbore skin zone”,play a pivotal role in determining flow dynamics and the resulting formation *** models of the wellbore skin zone generally assume a constant permeability throughout,resulting in a sharp permeability discontinuity at the skin-reservoir *** paper introduces a model for a wellbore with a continuously graded skin zone of finite thickness within a poroelastic *** solutions are derived using the Laplace transform method,addressing both positive and negative skin *** results are presented to illustrate the effects of graded permeability/skin zone thickness on pore pressures and stresses around a *** results highlight a distinct divergence in stress and pore pressure fields when comparing wellbores with negative skin zones to those with positive skin zones or no skin at all.

关键词： Poroelastic Graded permeability Analytical solution Wellbore Skin zone

Surface heterojunction based on n-type low-dimensional perovskite film for highly efficient perovskite tandem solar cells

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2024年第05期11卷 244-253页

作者： Xianyuan Jiang Qilin Zhou Yue Lu Hao Liang Wenzhuo Li Qi Wei Mengling Pan Xin Wen Xingzhi Wang Wei Zhou Danni Yu Hao Wang Ni Yin Hao Chen Hansheng Li Ting Pan mingyu Ma Gaoqi Liu Wenjia Zhou Zhenhuang Su Qi Chen Fengjia fan fan Zheng Xingyu Gao Qingqing Ji Zhijun Ning School of Physical Science and Technology Shanghai Tech University Department of Modern Physics University of Science and Technology of China i-Lab CAS Key Laboratory of Nanophotonic Materials and Devices Suzhou Institute of Nano-Tech and Nano-Bionics Shanghai Synchrotron Radiation Facility (SSRF) Shanghai Advanced Research InstituteChinese Academy of Sciences

Enhancing the quality of junctions is crucial for optimizing carrier extraction and suppressing recombination in semiconductor devices. In recent years, metal halide perovskite has emerged as the most promising next-generation material for optoelectronic devices. However, the construction of high-quality perovskite junctions, as well as characterization and understanding of their carrier polarity and density,remains a challenge. In this study, using combined electrical and spectroscopic characterization techniques,we investigate the doping characteristics of perovskite films by remote molecules, which is corroborated by our theoretical simulations indicating Schottky defects consisting of double ions as effective charge *** a post-treatment process involving a combination of biammonium and monoammonium molecules, we create a surface layer of n-type low-dimensional perovskite. This surface layer forms a heterojunction with the underlying 3D perovskite film, resulting in a favorable doping profile that enhances carrier extraction. The fabricated device exhibits an outstanding open-circuit voltage(VOC) up to 1.34 V and achieves a certified efficiency of 19.31% for single-junction wide-bandgap（1.77 eV） perovskite solar cells, together with significantly enhanced operational stability, thanks to the improved separation of carriers. Furthermore, we demonstrate the potential of this wide-bandgap device by achieving a certified efficiency of 27.04% and a VOCof 2.12 V in a perovskite/perovskite tandem solar cell configuration.

关键词： perovskite solar cells field effect transistors heterojunction

A progressive framework for rotary motion deblurring

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第2期32卷 159-172页

作者： Jinhui Qin Yong Ma Jun Huang fan fan You Du School of Electronic Information Wuhan UniversityWuhan430072China

The rotary motion deblurring is an inevitable procedure when the imaging seeker is mounted in the rotating *** rotary motion deblurring methods suffer from ringing artifacts and noise,especially for large blur *** solve the above problems,we propose a progressive rotary motion deblurring framework consisting of a coarse deblurring stage and a refinement *** the first stage,we design an adaptive blur extents factor(BE factor)to balance noise suppression and details *** a novel deconvolution model is proposed based on BE *** the second stage,a triplescale deformable module CNN(TDM-CNN)is designed to reduce the ringing artifacts,which can exploit the 2D information of an image and adaptively adjust spatial sampling *** establish a standard evaluation benchmark,a real-world rotary motion blur dataset is proposed and released,which includes rotary blurred images and corresponding ground truth images with different blur *** results demonstrate that the proposed method outperforms the state-of-the-art models on synthetic and real-world rotary motion blur *** code and dataset are available at https://***/JinhuiQin/RotaryDeblurring.

关键词： Rotary motion deblurring Progressive framework Blur extents factor TDM-CNN

上向连续进路尾砂充填法回采顶底柱的采场稳定性分析

在线全文

学校读者我要写书评

暂无评论

中国矿山工程 2007年第3期36卷 17-22,47页

作者：樊明玉山东科技大学资环学院山东青岛266510

利用基于有限元基本理论的数值模拟方法,采用极限分析方法分析护顶层的力学稳定性,确定了进路跨度与护顶矿层厚度的关系,推荐超前注浆造顶上向进路尾砂充填连续采矿法回采方案。

关键词：顶底柱超前注浆回采顺序

Seismic response of pile-supported structures considering the coupling of inertial and kinematic interactions in different soil sites

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2024年第9期18卷 1350-1361页

作者： Huiling ZHAO fan ZHANG Department of Civil Engineering Shanghai UniversityShanghai 200444China

Dynamic soil−pile−superstructure interaction is crucial for understanding pile behavior in earthquake-prone *** the safety of piles requires determining the seismic bending moment caused by combined inertial and kinematic interactions,which is *** paper addresses this problem through numerical simulations of piles in different soil sites,considering soil *** reveal that the period of the soil site significantly affects the interaction among soil,piles,and *** moments in soft and hard soil sites exceed those in medium soil sites by more than *** modes of piles exhibit distinct characteristics between hard and soft soil *** soil sites exhibit a singular inflection point,while hard soil sites show two inflection *** soft soil sites,pile-soil kinematic interaction gradually increases bending moment from tip to head,with minor influence from superstructure’s inertial *** hard soil sites,significant inertial effects from soil,even surpassing pile-soil kinematic effects near the tip,lead to reversed superposition bending ***’s inertial interaction notably impacts pile head in hard soil sites.A simplified coupling method is proposed using correlation coefficient to represent inertial and kinematic *** findings provide insights into complex seismic interactions among soil,piles,and structures.

关键词： pile seismic response soft soil inertial interaction kinematic interaction

Impact of non-ideal UE hardware on cell-free massive MIMO network with centralized operation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第4期67卷 255-271页

作者： Ning LI Pingzhi fan Institute of Mobile Communications Southwest Jiaotong University

This paper investigates the impact of non-ideal user equipment(UE) hardware on a cell-free(CF) massive MIMO(mMIMO) network with centralized operation under spatially correlated channels. The minimum mean-squared error(MMSE) estimator can be derived with the help of the generic non-ideal UE hardware model. It is demonstrated that even if the effective signal-to-noise ratio approaches infinity, pilot contamination and imperfect hardware can cause a non-zero estimation error floor. After that, a lower bound is determined for the ergodic uplink capacity of the centralized CF mMIMO network under non-ideal UE hardware. Moreover, the optimal receive combining vector is obtained to maximize the uplink spectral efficiency(SE). The maximum ratio(MR) and regularized zero-forcing(RZF) combining schemes are offered as alternatives in light of the computational complexity of the MMSE receiver. Comparing the RZF to the MMSE scheme under different levels of hardware impairments, our findings indicate that the RZF receiver suffers a negligible loss in total SE. For MR combining, a novel closed-form uplink achievable SE expression is obtained based on the MMSE estimator and the use-and-then-forget bounding technique. This expression gives vital insights into the achievable uplink performance with UE hardware impairments. Besides, for various hardware impairment factors, the impact of pilot sequence length on average sum SE is disclosed for different receive combining schemes. To increase the overall SE of the max-min fairness scheme, a heuristic fractional power control scheme with UE hardware impairments is developed, which can essentially avoid sacrificing the SE of other UEs while maximizing the SE of the unluckiest UE in the whole network. Finally,our theoretical performance analysis and power control algorithm are validated by simulation results, and fundamental design guidelines are provided for selecting hardware satisfying the practical UE requirements.

关键词： cell-free massive MIMO centralized operation spatially correlated channels hardware impairments channel estimation uplink spectral efficiency optimal receive combining pilot length design fractional power control