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SUBSPACE-BASED NOISE VARIANCE AND SNR ESTIMATION FOR MIMO OFDM SYSTEMS

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Journal of Electronics(China) 2006年第2期23卷 176-180页

作者： xu xiaodong Jing Ya Zhao Junhui You Xiaohu National Mobile Communications Research Laboratory Southeast University Nanjing 210096 China Faculty of Information Technology Macao University of Science and Technology Macao China

This paper proposes a subspace-based noise variance and Signal-to-Noise Ratio (SNR) estimation algorithm for Multi-Input Multi-Output (MIMO) wireless Orthogonal Frequency Division Multiplexing (OFDM) systems. The special training sequences with the property of orthogonality and phase shift orthogonality are used in pilot tones to obtain the estimated channel correlation matrix. Partitioning the observation space into a delay subspace and a noise subspace, we achieve the measurement of noise variance and SNR. Simulation results show that the proposed estimator can obtain accurate and real-time measurements of the noise variance and SNR for various multipath fading channels, demonstrating its strong robustness against different channels.

关键词： Multi-Input Multi-Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) Noise variance Signal-to-Noise Ratio (SNR) Delay subspace Channel correlation matrix

Robust output regulation for a class of hyperbolic PDE systems based on DeepONet

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Robust output regulation for a class of hyperbolic PDE syste...

Self-Optimizing Gaussian Process Model for Online Detection of Model-Plant Mismatch Using Closed-Loop Operational Data

第35届中国过程控制会议

作者： Yu Xiao xiaodong xu xunyuan Yin Central South University School of Automation Nanyang Technological University School of Chemistry Chemical Engineering and Biotechnology

Thanks to the global approximation ability of the DeepONet in approximating operators from function spaces to other function spaces, the DeepONet has been employed as a gain solver in the backstepping stabilization control for boundary controllable PDE systems. Prior to the implementation, the DeepONet can be trained offline on a dataset containing a sufficient number of system parameters and correspondingly exact solutions of the kernel equations. Once the DeepONet is well-trained,as a gain solver it can generate approximate gain function with arbitrary accuracy, and more notably the solving time is greatly reduced compared with numerical PDE solver in generating gain function. In this paper, we extend the neural operator（NO）theory to a more complex field of robust regulation control for a class of hyperbolic PDE systems. Although the DeepONet cannot eliminate the approximation error, the regulator designed based on the internal model principle is robust to the error in approximate gain and a certain degree of parameter uncertainty. Therefore, the tracking error can still converge to 0 if the extended regulator equation is solvable. A series of theory proofs of the regulation problem and a numerical test under the approximate gain are presented. It is shown that NO is almost three orders of magnitude faster than PDE solver in generating kernel function, and the loss remains on the order of 10. This provides a new insight to use the NO methodology for accelerated gain scheduling regulation for PDEs with time-varying parameters.

关键词： DeepONet Neural operator Hyperbolic PDE systems Robust output regulation

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Self-Optimizing Gaussian Process Model for Online Detection ...

Semantic theory of finite lattice-valued propositional logic

第35届中国过程控制会议

作者： Zhihao Liu xiaodong xu xunyuan Yin School of Chemistry Nanyang Technological University

In control strategies such as real-time optimization(RTO) and model predictive control(MPC), the quality of the model is crucial for effective control. However, in practical applications, various uncertainties often lead to mismatch between the model and the actual plant inevitablely. To detect mismatch without interrupting the production process, online detecting from closed-loop operational data is an ideal approach. This article proposes a mismatch detection method based on Gaussian process(GP) modeling, integrated with classical RTO and MPC, to achieve mismatch detection. The GP model is trained using a training dataset, employing a combination of Radial Basis Function(RBF) and linear kernels, and optimizing the model's hyperparameters using maximum likelihood estimation, thereby enhancing the predictive capability of the GP model. The proposed method is non-intrusive and applicable to nonlinear systems with multiple inputs and outputs. To validate the effectiveness of the proposed method, we apply it to detect model-plant mismatch in a continuous stirred-tank reactor esterification model. The results demonstrate that regardless of whether the parameter variations are within the training set's range, this method can accurately predict and update the parameters of RTO and MPC models.

关键词： continuous stirred tank reactor Gaussian processes parameter estimation predictive control

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Science China(Information Sciences) 2010年第10期53卷 2022-2031页

作者： PAN xiaodong 1,2 & xu Yang 2 1 School of Maths, Southwest Jiaotong University, Chengdu 610031, China 2 Intelligent Control Development Center, Southwest Jiaotong University, Chengdu 610031, China School of Maths Southwest Jiaotong University Chengdu China Intelligent Control Development Center Southwest Jiaotong University Chengdu China

Based on the methodology of Pavelka’s fuzzy propositional logic, in this paper, by combining L-fuzzy set and classical two-value propositional logic theory, a kind of graded semantic theory in lattice-valued propositional logic based on finite lattice implication algebras is established. The notions of L-tautology and L-contradiction are introduced, and several theorems about the relations among different kinds of L-tautologies are given. From the viewpoint of uncertainty reasoning, the notion of satisfiability with certain level for a set of formulas is also defined. On this basis, the semantic consequence operation concerning a set of formulas is proposed, and the properties of semantic consequence operation and the consistency of fuzzy information are discussed.

关键词： lattice-valued propositional logic semantic theory L-tautology consistency lattice implication algebra

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尊重城市回归经典——中广核大厦设计回顾

建筑学报 2019年第3期 73-74页

作者：许小东 URBANUS都市实践建筑事务所深圳518053

超高层建筑的持续兴建往往标志着一座城市乃至一个国家经济社会发展卓有成效。随着这些超高层建筑雨后春笋般拔地而起的也是城市建设者们冉冉升腾的“雄心壮志”。这种内在的精神驱动与建国初期"处处烟囱林立”的“豪情满怀”一脉相承... 详细信息

超高层建筑的持续兴建往往标志着一座城市乃至一个国家经济社会发展卓有成效。随着这些超高层建筑雨后春笋般拔地而起的也是城市建设者们冉冉升腾的“雄心壮志”。这种内在的精神驱动与建国初期"处处烟囱林立”的“豪情满怀”一脉相承。不可否认,在“大干快上”的历史时期,这番预想的“城市景象”带给了人们对未来城市的无限遐想,也带来精神上的巨大鼓舞与行动上的强大力量。

关键词：城市建设超高层建筑设计大厦归经经济社会发展未来城市烟囱

A Low-Cost Outdoor Fingerprinting Localization Scheme For Wireless Cellular Networks

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ZTE Communications 2019年第3期17卷 42-49页

作者： PEI Dengke xu xiaodong QIN Xiaowei LIU Dongliang ZHAO Chunhua Department of Electronic Engineering and Information Science University of Science and Technology of China

This paper considers outdoor fingerprinting localization in LTE cellular Networks,which can localize non-cooperative user equipment(UE)that is unwilling to provide Global Positioning System(GPS)*** propose a low-cost fingerprinting localization scheme that can improve the localization accuracy while reducing the computational ***,a data filtering strategy is employed to filter the fingerprints which are far from the target UE by using the Cell-ID,Timing Advance(TA)and eNodeB environment information,and the distribution of TA difference is analyzed to guide how to use TA rationally in the filtering ***,improved Weighted K Nearest Neighbors(WKNN)are implemented on the filtered fingerprints to give the final location prediction,and the WKNN is improved by removing the fingerprints that are still far away from the most of the K *** results show that the performance is improved by the proposed localization scheme,and positioning errors corresponding to Cumulative Distribution Function(CDF)equaling to 67% and 95% are declined to 50 m and 150 m.

关键词： fingerprinting localization TA filtering strategy improved WKNN

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髓源抑制性细胞与肾脏疾病

肾脏病与透析肾移植杂志 2016年第1期25卷 67-71页

作者：徐孝东鲍浩南京军区南京总医院肾脏科国家肾脏疾病临床医学研究中心全军肾脏病研究所南京210016

髓源抑制性细胞(MDSCs)是一类未成熟且具有免疫负调控作用的髓系细胞群体,在维持机体免疫平衡和慢性肾脏病的发生发展中起重要作用。MDSCs为一群异质性的细胞群体,对其细胞表型和作用机制目前并未完全阐明,本文就MDSCs的来源、表型鉴定... 详细信息

髓源抑制性细胞(MDSCs)是一类未成熟且具有免疫负调控作用的髓系细胞群体,在维持机体免疫平衡和慢性肾脏病的发生发展中起重要作用。MDSCs为一群异质性的细胞群体,对其细胞表型和作用机制目前并未完全阐明,本文就MDSCs的来源、表型鉴定及在肾脏疾病中的作用做一综述。

关键词：髓源抑制性细胞肾脏疾病

Establishment and Analysis of the Fault Tree for the Oil Transfer Pump System in CNPC Work Zone

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International Journal of Plant Engineering and Management 2014年第3期19卷 150-172页

作者： HUANG Hui WANG Qiusheng GAO Jie YANG Jiaqi xu xiaodong School of Management Northwestern Polytechnical University Huaxin Consulting Co. Ltd

The reliability of the equipment is very important for the large petrochemical industry, especially for oil pump as the core component of driving equipment. In order to reduce the loss of the enterprise brought by equipment failure, it is need to find those reasons which may lead to equipment failure and take some preventive measures as early as possible. This article analyzes the failure of the oil transfer pump system in CNPC work zone systematically, qualitatively and quantitatively, using the fault tree analysis method. Then 105 groups of minimal cut sets are found, and the probability of system failure after a certain time operation is calculated by using Weibull distribution. Combined with specific requirements of reliability, the work zone may make a scientific decision of plant maintenance cycle according to the conclusion.

关键词： fault tree reliability Weibull distribution plant maintain and management

Physiological, Enzymatic and Molecular Changes of Acipenser schrencki Induced by Heat Exposure

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Animal Husbandry and Feed Science 2022年第1期14卷 39-44页

作者： Wan Qianhui Tian Shimao Kong Yingying xiaodong xu Qi Baomin College of Animal Science FujianAgriculture and Forestry UniversityFuzhou 350002China

[Objective] The paper was to understand the physiological, enzymatic and molecular changes of Acipenser schrencki induced by heat exposure. [Method] The effects of heat exposure on A. schrencki were investigated. The temperature was increased from(18± 0.5) ℃ by 0.08 ℃/min and respectively kept at(32±0.5) ℃ for 2, 4 and 6 h. The respiration rate, related biochemical indicators and heat shock protein 70(Hsp 70) mR-NA expression were investigated. [Result] At(32±0.5) ℃, the activities of total protein, albumin, globulin, urea nitrogen, ceatinine, malondialde-hyde, aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase fluctuated dramatically from 2 h to 6 h. Meanwhile, the respi-ration rate and Hsp 70 m RNA expression in heart, liver and spleen were significantly increased from 2 h to 6 h. In comparison, the lower respira-tion rate and tiny fluctuations in activities of biochemical indicators were consistent with the lower Hsp 70 expression. [Conclusion] During the process of heat stress, A. schrencki seems to be sensitive to such temperature, and manifests generally consistent gill breathing, biochemical indica-tors and Hsp70 gene expression, implying better heat tolerance.

关键词： Acipenser schrencki Biochemical indicators Heat exposure Hsp70 mRNA