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DISTRIBUTION OF ACTIVE EARTH PRESSURE OF RETAINING WALL WITH WALL MOVEMENT OF ROTATION ABOUT TOP

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Applied Mathematics and Mechanics(English Edition) 2004年第7期25卷 761-767页

作者：王元战唐照评郑斌 School of Civil Engineering China communications Fourth Design institute of Navigation

Based on the Coulomb's theory that the earth pressure against the back of a retaining wall is due to the thrust exerted by the sliding wedge of soil from the back of the wall to a plane which passes through the bottom edge of the wall and has an inclination equal to the angle of θ, the theoretical answers to the unit earth pressure, the resultant earth pressure and the point of application of the resultant earth pressure on a retaining wall were obtained for the wall movement mode of rotation about top. The comparisons were made among the formula presented here, the formula for the wall movement mode of translation, the Coulomb's formula and some experimental observations. It is demonstrated that the magnitudes of the resultant earth pressures for the wall movement mode of rotation about top is equal to that determined by the formula for the wall movement mode of translation and the Coulomb's theory. But the distribution of the earth pressure and the points of application of the resultant earth pressures have significant difference.

关键词： retaining wall rotation about top active earth pressure distribution point of application

Doppler-resilient waveform design in integrated MIMO radar-communication systems

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Science China(Information Sciences) 2024年第1期67卷 187-202页

作者： Zhengchun ZHOU Bing LIU Bingsheng SHEN Avik Ranjan ADHIKARY Pingzhi FAN institute of Mobile communications Southwest Jiaotong University Department of Mathematics Southwest Jiaotong University

In recent years,the increased high-rate wireless services(5G and 6G) and reliable sensing capabilities(automotive radar,air traffic control,geophysical monitoring),have led to more serious spectrum ***,radars and communication systems are often seen to be “competing” for the same *** this scenario,an integrated platform for radar and communication systems seems to be an optimal solution to address the *** this paper,we propose a preamble waveform design based on zero-correlation zone(ZCZ) and zero odd-correlation zone(ZOCZ) sequence sets,which are Doppler resilient in multiple-input,multiple-output(MIMO) *** preamble waveforms can be simultaneously used for channel estimation and radar sensing in RadCom *** ambiguity function of the proposed waveforms displays low/zero sidelobes within a time-delay correlation ***,we give some numerical results to show the efficiency of the proposed waveforms in radar sensing and channel estimation.

关键词： ambiguity function correlation channel estimation integrated radar and communication (Rad-Com) systems MIMO radar zero correlation zone (ZCZ) sequence set zero odd-correlation zone (ZOCZ) sequence set

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A scalable and low power VLIW DSP core for embedded system design

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Journal of Harbin institute of Technology(New Series) 2008年第2期15卷 172-175页

作者： Sheraz Anjum 陈杰韩亮林川张晓潇苏叶华程亚奇 communications and Multimedia SoC Lab Institute of Microelectronics Chinese Academy of Sciences communications and Multimedia SoC Lab Institute of MicroelectronicsChinese Academy of Sciences communications and Multimedia SoC Lab Institute of Microelectronics Chinese Academy of Sciences

Aims to provide the block architecture of CoStar3400 DSP that is a high performance, low power and scalable VLIW DSP core, it efficiently deployed a variable-length execution set (VLES) execution model which utilizes the maximum parallelism by allowing multiple address generations and data arithmetic logic units to execute multiple instructions in a single clock cycle. The scalability was provided mainly in using more or less number of functional units according to the intended application. Low power support was added by careful architectural design techniques such as fine-grain clock gating and activation of only the required number of control signals at each stage of the pipeline. The said features of the core make it a suitable candidate for many SoC configurations, especially for compute intensive applications such as wire-line and wireless communications, including infrastructure and subscriber communications. The embedded system designers can efficiently use the scalability and VLIW features of the core by scaling the number of execution units according to specific needs of the application to effectively reduce the power consumption, chip area and time to market the intended final product.

关键词： Very Long Instruction Word (VLIW) low Dower DSP compute intensive system on chip (SoC)

Algorithm for solving problems related to the natural vibrations of electro-viscoelastic structures with shunt circuits using ANSYS data

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International Journal of Smart and Nano Materials 2019年第2期10卷 156-176页

作者： Nataliia Iurlova Natalia Sevodina Dmitrii Oshmarin Maksim Iurlov institute of Continuous media Mechanics of the Ural Branch of RAS PermRussian Federation

An algorithm for numerical realisation of a mathematical statement of the natural vibrations problem for electro-viscoelastic bodies with passive external electric circuits(*** circuits)with an arbitrary configuration using the finite element method is proposed in the present *** proposed algorithm allows considering the viscoelastic properties of materials using the model of linear hereditary viscoelasticity with complex dynamic moduli and is used to solve 3D solid structure problems that are compatible for ANSYS package element *** technique implies the usage of the global assembled matrices of stiffness and mass,formed in the ANSYS *** basis of the algorithm is a novel approach that allows performing decomposition of the global assembled stiffness matrix formed in the ANSYS software package into constituents that are needed for calculation of the natural vibration frequencies of the objects under *** matrix components are used in the program that was written in FORTRAN(Formula Translation)*** problem could be efficiently applied for analysis of the dynamic processes in smart systems based on piezoelectric materials and could also form a basis for the development of numerical finite element algorithms for optimization of the dissipative characteristics of electromechanical systems with shunted piezoelectric elements.

关键词： Numerical simulation finite element method electroviscoelasticity piezoelement external electric circuit natural vibrations

Efficient Mechanisms to Improve TCP Performance over OBS Networks

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China communications 2010年第2期7卷 87-91页

作者： Hong Xiaobin, Zhou Jun, Wu Jian, Guo Hongxiang, Zuo Yong, Xu Kun, Lin Jintong Key Laboratory of Information Photonics and Optical communications, Ministry of Education institute of Optical communications and Optoelectronics, Beijing University of Posts and Telecommunications, Beijing 100876, China Key Laboratory of Information Photonics and Optical communications Ministry of Education institute of Optical communications and Optoelectronics Beijing University of Posts and Telecommunications

Transmission Control Protocol (TCP) performance over Optical Burst Switching (OBS) is experimentally investigated on an OBS network testbed, concluding that burst losses will lead to a significant drop in the available TCP bandwidth. Two mechanisms are introduced to improve TCP performance. One is concerning the burst assembly optimization and another is based on the novel assembly and scheduling mechanism to reduce the burst losses.

关键词： OBS ACK TCP burst loss probability scheduling algorithm

Channel capacity investigation of a linear massive MIMO system using spherical wave model in LOS scenarios

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Science China(Information Sciences) 2016年第2期59卷 45-59页

作者： Liu LIU David W.MATOLAK Cheng TAO Yongzhi LI Bo AI Houjin CHEN institute of Broadband Wireless Mobile communications Beijing Jiaotong University Department of Electrical Engineering University of South Carolina National Mobile communications Research Laboratory Southeast University

Massive multiple-input multiple-output(MIMO) is a key technology for the 5th generation(5G)of wireless communication systems. The traditional plane wave channel model(PWM) is often not suitable for the large antenna structure, and in certain cases should be replaced by the more accurate spherical wave model(SWM). By using the spherical wave characterization method, this paper investigates the channel capacity performance of a linear massive MIMO system in line-of-sight(LOS) scenarios. Two types of access settings, the point to point(PTP) system and multi-user(MU) system, are considered. In the PTP setting, a geometrical optimization is performed to obtain configurations that are able to generate a full rank channel matrix for a linear massive MIMO system, which yields full spatial diversity even in LOS scenarios. Compared with the approximate and commonly applied rank-1 PWM, this is very useful for fixed wireless access and radio relay systems requiring high throughput. For the MU case, we compare the eigenvalue distributions of the LOS channels using the plane wave and spherical wave characterization method, and sum rate results are obtained by Monte Carlo simulations. The results show that MU systems using the more realistic and accurate SWM can achieve a higher sum rate than results from the PWM. This is beneficial and informative when designing massive MIMO wireless networks.

关键词： massive MIMO channel model plane wave model spherical wave model channel capacity

Improving Expectation Propagation with Lattice Reduction for Massive MIMO Detection

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China communications 2018年第12期15卷 49-54页

作者： Senjie Zhang Shi Jin Chao-Kai Wen Zhiqiang He Key Laboratory of Universal Wireless communications Ministry of Education Beijing University of Posts and Telecommunications National Mobile communications Research Laboratory Southeast University institute of communications Engineering Sun Yat-sen University

Efficient massive MIMO detection for practical deployment, which is with spatially correlated channel and high-order modulation, is a challenging topic for the fifth generation mobile communication(5 G). In this paper, we propose a lattice reduction aided expectation propagation(LRA-EP) algorithm for massive MIMO detection. LRA-EP applies expectation propagation in lattice reduced MIMO system to approach the distribution of lattice reduced constellation point by iterative refinement on its parameters(mean and covariance). The parameter refinement is based on the lattice reduced, well-conditioned MIMO channel. Numerical result shows that LRA-EP outperforms classic EP based MIMO detection(EPD) with 5～7 dB in terms of required signalto-noise ratio(SNR) for 1% packet error rate in spatially correlated channel for 256-QAM. We also show that LRA-EP has lower computation complexity than EPD.

关键词： MIMO detection lattice reduction expectation propagation massive MIMO

DYNAMIC RESPONSE OF ELASTIC LAYER ON STIFF FOUNDATION UNDER TIME HARMONIC SURFACE VERTICAL CONCENTRATED LOAD

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Applied Mathematics and Mechanics(English Edition) 1987年第10期8卷 919-927页

作者：郑健龙 Changsha Changsha communications institute

In lhis paper,the line-load integral equation method proposed in reference[1] is firstused for solving the elastodynamic problems.A set of one-dimensional regular integralequation is derived for calculating the dynamic response of elastic layer on stiff foundationunder time harmonic surface vertical concentraled load And the numerical solution of theintegral equation is obtained.

关键词： exp In 一彻 DYNAMIC RESPONSE OF ELASTIC LAYER ON STIFF FOUNDATION UNDER TIME HARMONIC SURFACE VERTICAL CONCENTRATED LOAD

Stretch-Minimizing Volumetric Parameterization

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Journal of Computer Science & Technology 2015年第3期30卷 553-564页

作者：金耀钱归平赵杰伊常建童若锋张建军 Department of Computer Science and Engineering Zhejiang University Hangzhou 310027 China College of New media Zhejiang University of Media and Communications Hangzhou 310018 China National Centre for Computer Animation Bournemouth University Bournemouth BH12 5BB U.K.

Not many methods for parameterization guarantee bijectivity or local injectivity, which is essential for foldover- free mappings. Stretch-minimizing parameterization which is widely used for surface parameterization, provides foldover-free mappings and is capable of trading off between angle and area distortions. We extend its usage to volumetric parameterization in this paper by deriving a 3D version of stretch-distortion energy and incorporating fixed boundary conditions. Our energy definition includes a naturM barrier term which effectively prevents elements from collapsing and folding over. It saves the effort in other methods of formulating additional energy or constrains to ensure the local injectivity. We propose to minimize the overall energy integrated over the whole mesh with a relaxation-enhanced solver and optimize the energy globally. This is different from the conventional approach of surface parameterization where mesh nodes are optimized individually. Compared with other volumetric parameterizations, method, being foldover-free and offering a good trade-off between our approach bears the advantages of stretch-minimizing angle and volume distortions.

关键词： stretch-minimizing volumetric parameterization foldover-free