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Dual Waterfilling Power Allocation Algorithm in MIMO Systems

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China Communications 2009年第3期6卷 144-149页

作者： Rong Mei Zhu shihua li Feng School of Electronics and Information Engineering Xi＇an Jiaotong University Xi＇an 710049 China

Aiming at the problem of resource allocation in multiuser multi-input multi-output (MIMO)systems,a new power allocation algorithm based on dual waterfilling is *** diagonalization is adopted to cancel the inter-user interference,and then the complete diagonalization method is employed to derive the spatial sub-channels for each *** overall power of the system is divided among users based on each user’s large scale fading;then the power of each user is further allocated to its spatial sub-channels based on the small scale *** results show that compared with the existing resource allocation strategies,the proposed algorithm can provide more ergodic capacity for multi-user MIMO *** the total transmit power is 100w,it has 15%capacity advantage over the traditional waterfilling method.

关键词： waterfilling resource allocation ergodic capacity

Finite-time Feedback Stabilization of a Class of Input-delay Systems With Saturating Actuators via Digital Control

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IEEE/CAA Journal of Automatica Sinica 2019年第5期6卷 1281-1290页

作者： Xiangze lin Shuaiting Huang Wanli Zhang shihua li the College of Engineering Nanjing Agricultural UniversityNanjing 210031China the School of Automation Southeast UniversityNanjing 210096China

In this paper, the problem of making an input-delay system with saturating actuators finite-time stable by virtue of digital control is investigated. A digital state feedback controller and digital observer-controller compensator are designed for two cases: when the state of the input-delay system are available or when it is unavailable. Sufficient conditions which guarantee finite-time stability of a closed-loop input-delay system are given and the proof procedure is presented in a heuristic way by constructing appropriate comparison functions. The condition can be transformed into the intersection of two curves satisfying some constraints, which reveals the relationship between designed parameters clearly. Finally, simulation results are presented to validate the method proposed in this paper.

关键词： Digital control finite-time stability input-delay system saturating actuator

Type Synthesis of Fully Decoupled Three Translational Parallel Mechanism with Closed-Loop Units and High Stifness

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Chinese Journal of Mechanical Engineering 2023年第5期36卷 231-247页

作者： shihua li Sen Wang Haoran li Yongjie Wang Shuang Chen Hebei Provincial Key Laboratory of Parallel Robot and Mechatronic Systems Yanshan UniversityQinhuangdao 066004China

In order to solve the problem of weak stifness of the existing fully decoupled parallel mechanism, a new synthesis method of fully decoupled three translational (3T) parallel mechanisms (PMs) with closed-loop units and high stifness is proposed based on screw theory. Firstly, a new criterion for the full decoupled of PMs is presented that the reciprocal product of the transmission wrench screw matrix and the output twist screw matrix of PMs is a diagonal matrix, and all elements on the main diagonal are nonzero constants. The forms of the transmission wrench screws are determined by the criterion. Secondly, the forms of the actuated and unactuated screws can be obtained according to their relationships with the transmission wrench screws. The basic decoupled limbs are generated by combination of the above actuated and unactuated screws. Finally, a closed-loop units construction method is investigated to apply the decoupled mechanisms in a better way on the high stifness occasion. The closed-loop units are constructed in the basic decoupled limbs to generate a high-stifness fully decoupled 3T PM. Kinematic and stifness analyses show that the Jacobian matrix is a diagonal matrix, and the stifness is obviously higher than that of the coupling mechanisms, which verifes the correctness of the proposed synthesis method. The mechanism synthesized by this method has a good application prospect in vehicle durability test platform.

关键词： Screw theory Three translational parallel mechanism Full decoupled Closed-loop units High stifness

Stability analysis for a second-order continuous finite-time control system subject to a disturbance

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控制理论与应用（英文版） 2009年第3期7卷 271-276页

作者： Shihong DING shihua li Qi li School of Automation Southeast University Nanjing Jiangsu 210096 China

In this paper, using finite-time control method, we consider the disturbance analysis of a second-order system with unknown but bounded disturbance. We show that the states of the second-order system will be stabilized to a region containing the origin. The radius of this region is determined by the control parameters and can be rendered as small as desired. The rigorous stability analysis is also given. Compared with the conventional PD control law, the finite-time control law yields a better disturbance rejection performance. Numerical simulation results show the effectiveness of the method.

关键词： Finite-time control Second-order system Disturbance analysis Bounded disturbance

Special focus on advances in disturbance/uncertainty estimation and attenuation techniques with applications

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Science China(Information Sciences) 2018年第7期61卷 180-181页

作者： shihua li Lei GUO Kouhei OHNISHI Southeast University Beihang University Keio University

Disturbances and uncertainties exist in most engineering systems and always result in adverse effects on the control performances of closed-loop *** design and analysis of nonlinear control systems under disturbances is an active research topic in control systems *** advanced disturbance/uncertainty estimation and attenuation(DUEA)techniques have been developed to deal with systems in the presence of various disturbances and parametric uncertainties,e.g.,stochastic control,

关键词： Special focus on advances in disturbance/uncertainty estimation and attenuation techniques with applications

CRISPR-Based Genome-Editing Tools for Huntington’s Disease Research and Therapy

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Neuroscience Bulletin 2022年第11期38卷 1397-1408页

作者： Yiyang Qin shihua li Xiao-Jiang li Su Yang Guangdong Key Laboratory of Non-human Primate Research Guangdong-Hongkong-Macao Institute of CNS RegenerationJinan UniversityGuangzhou 510632China

Huntington’s disease(HD)is an autosomal dominantly-inherited neurodegenerative disease,which is caused by CAG trinucleotide expansion in exon 1 of the Huntingtin(HTT)*** HD is a rare disease,its monogenic nature makes it an ideal model in which to understand pathogenic mechanisms and to develop therapeutic strategies for neurodegenerative *** regularly-interspaced short palindromic repeats(CRISPR)is the latest technology for genome *** simple to use and highly efficient,CRISPR-based genome-editing tools are rapidly gaining popularity in biomedical research and opening up new avenues for disease ***,we review the development of CRISPR-based genome-editing tools and their applications in HD research to offer a translational perspective on advancing the genome-editing technology to HD treatment.

关键词： Huntington’s disease CRISPR Animal models

New pathogenic insights from large animal models of neurodegenerative diseases

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Protein & Cell 2022年第10期13卷 707-720页

作者： Peng Yin shihua li Xiao-Jiang li Weili Yang Guangdong Key Laboratory of Non-human Primate Research Guangdong-Hongkong-Macao Institute of CNS RegenerationJinan UniversityGuangzhou 510632China

Animal models are essential for investigating the pathogenesis and developing the treatment of human *** of genetic mutations responsible for neurodegenerative diseases has enabled the creation of a large number of small animal models that mimic genetic defects found in the affected *** the current animal models,rodents with genetic modifications are the most commonly used animal models and provided important insights into ***,most of genetically modified rodent models lack overt neurodegeneration,imposing challenges and obstacles in utilizing them to rigorously test the therapeutic effects on *** studies that used CRISPR/Cas9-targeted large animal(pigs and monkeys)have uncovered important pathological events that resemble neurodegeneration in the patient’s brain but could not be produced in small animal *** we highlight the unique nature of large animals to model neurodegenerative diseases as well as the limitations and challenges in establishing large animal models of neurodegenerative diseases,with focus on Huntington disease,Amyotrophic lateral sclerosis,and Parkinson *** also discuss how to use the important pathogenic insights from large animal models to make rodent models more capable of recapitulating important pathological features of neurodegenerative diseases.

关键词： large animal models neurodegenerative diseases CRISPR/Cas9

Pathological insights from amyotrophic lateral sclerosis animal models:comparisons,limitations,and challenges

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Translational Neurodegeneration 2023年第1期12卷 242-257页

作者： Longhong Zhu shihua li Xiao-Jiang li Peng Yin Guangdong Key Laboratory of Non-Human Primate Research Key Laboratory of CNS Regeneration(Ministry of Education)GHM Institute of CNS RegenerationJinan UniversityGuangzhou 510632China

In order to dissect amyotrophic lateral sclerosis(ALS),a multigenic,multifactorial,and progressive neurodegenerative disease with heterogeneous clinical presentations,researchers have generated numerous animal models to mimic the genetic *** and comparative analysis of these various models allows identification of the causes and mechanisms of ALS in order to finally obtain effective ***,most genetically modified rodent models lack overt pathological features,imposing challenges and limitations in utilizing them to rigorously test the potential *** studies using large animals,including pigs and non-human primates,have uncovered important events that resemble neurodegeneration in patients’brains but could not be produced in small *** we describe common features as well as discrepancies among these models,highlighting new insights from these ***,we will discuss how to make rodent models more capable of recapitulating important pathological features based on the important pathogenic insights from large animal models.

关键词： Amyotrophic lateral sclerosis Animal model Rodent Non-human primate

Synthesis of Branched Chains with Actuation Redundancy for Eliminating Interior Singularities of 3T1R Parallel Mechanisms

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Chinese Journal of Mechanical Engineering 2016年第2期29卷 250-259页

作者： li shihua liU Yanmin CUI Hongliu NIU Yunzhan ZHAO Yanzhi Hebei Provincial Key Laboratory of Parallel Robot and Mechatronic System Yanshan University Qinhuangdao 066004 China Hebei Vocationa & Technical College of Building Materials Qinhuangdao 066004 China

Although it is common to eliminate the singularity of parallel mechanism by adding the branched chain with actuation redundancy, there is no theory and method for the configuration synthesis of the branched chain with actuation redundancy in parallel mechanism. Branched chains with actuation redundancy are synthesized for eliminating interior singularity of 3-translational and 1-rotational（3T1R） parallel mechanisms. Guided by the discriminance method of hybrid screw group according to Grassmann line geometry, all the possibilities are listed for the occurrence of interior singularities in 3T1R parallel mechanism. Based on the linear relevance of screw system and the principles of eliminating parallel mechanism singularity with actuation redundancy, different types of branched chains with actuation redundancy are synthesized systematically to indicate the layout and the number of the branched chainsinterior with actuation redundancy. A general method is proposed for the configuration synthesis of the branched chains with actuation redundancy of the redundant parallel mechanism, and it builds a solid foundation for the subsequent performance optimization of the redundant actuation parallel mechanism.

关键词： parallel mechanism interior singularity hybrid screw group branched chain with actuation redundancy