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RLS channel estimation with adaptive forgetting factor in space-time coded MIMO-OFDM systems

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第4期7卷 507-515页

作者： LIANG Yong-ming luo han-wen HUANG Jian-guo Department of Electronic Engineering Shanghai Jiao Tong University Shanghai 200030 China College of Marine Engineering Northwestern Polytechnical University. Xi＇an 710072 China

Considering that channel estimation plays a crucial role in coherent detection, this paper addresses a method of Recursive-least-squares (RLS) channel estimation with adaptive forgetting factor in wireless space-time coded multiple-input and multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) systems. Because there are three different forgetting factor scenarios including adaptive, two-step and conventional ones applied to RLS channel estimation, this paper describes the principle of RLS channel estimation and analyzes the impact of different forgetting factor scenarios on the performances of RLS channel estimation. Simulation results proved that the RLS algorithm with adaptive forgetting factor (RLS-A) outperformed that with two-step forgetting factor (RLS-T) or with conventional forgetting factor (RLS-C) in both estimation accuracy and robustness over the multiple-input multiple-output (MIMO) channel, i.e., a wide-sense stationary uncorrelated scattering (WSSUS) and frequency-selective slowly fading channel. Hence, we can employ the RLS-A method by adjusting forgetting factor adaptively to track and estimate channel state parameters successfully in space-time coded MIMO-OFDM systems.

关键词： MIMO-OFDM Channel estimation RLS algorithm Adaptive forgetting factor

Biodegradable Poly(propylene carbonate)/Layered Double Hydroxide Composite Films with Enhanced Gas Barrier and Mechanical Properties

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Chinese Journal of Polymer Science 2016年第1期34卷 13-22页

作者： Gao-feng Li Wen-han luo Min Xiao 王拴紧孟跃中 State Key Laboratory of Optoelectronic Materials and Technologies/The Key Laboratory of Low-carbon Chemistry &Energy Conservation of Guangdong Province Sun Yat-sen University

Relatively well crystallized and high aspect ratio Mg-Al layered double hydroxides（LDHs） were prepared by coprecipitation process in aqueous solution and further rehydrated to an organic modified LDH（OLDH） in the presence of surfactant. The intercalated structure and high aspect ratio of OLDH were verified by X-ray diffraction（XRD） and scanning electron microscopy（SEM）. A series of poly（propylene carbonate）（PPC）/OLDH composite films with different contents of OLDH were prepared via a melt-blending method. Their cross section morphologies, gas barrier properties and tensile strength were investigated as a function of OLDH contents. SEM results show that OLDH platelets are well dispersed within the composites and oriented parallel to the composite sheet plane. The gas barrier properties and tensile strength are obviously enhanced upon the incorporation of OLDH. Particularly, PPC/2%OLDH film exhibits the best barrier properties among all the composite films. Compared with pure PPC, the oxygen permeability coefficient（OP） and water vapor permeability coefficient（WVP） is reduced by 54% and 17% respectively with 2% OLDH addition. Furthermore, the tensile strength of PPC/2%OLDH is 83% higher than that of pure PPC with only small lose of elongation at break. Therefore, PPC/OLDH composite films show great potential application in packaging materials due to its biodegradable properties, superior oxygen and moisture barrier characteristics.

关键词： Poly(propylene carbonate) Layered double hydroxide Gas barrier properties Biodegradable composite Packaging

Attention-based LSTM predictive model for the attitude and position of shield machine in tunneling

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Underground Space 2023年第6期13卷 335-350页

作者： Qing Kang Elton J.Chen Zhong-Chao Li han-Bin luo Yong Liu State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan 430072China School of Civil&Hydraulic Engineering Huazhong University of Science&TechnologyWuhan 430074China Tunnel Engineering Company Wuhan Municipal Construction Group Co.LtdWuhan 430023China

Shield machine may deviate from its design axis during excavation due to the uncertainty of geological environment and the complexity of *** study therefore introduced a framework to predict the attitude and position of shield machine by combining long short-term memory(LSTM)model with attention *** data obtained from the Wuhan Rail Transit Line 6 project were utilized to verify the feasibility of the proposed *** adding the attention mechanism into the LSTM model,the proposed model can focus more on parameters with higher *** analysis based on Pearson correlation coefficient was conducted to improve the prediction efficiency and reduce the irrelevant input *** with LSTM model,LSTM-attention model has higher *** mean value of coefficient of determination(R^(2))increases from 0.625 to 0.736,and the mean value of root mean square error(RMSE)decreases from 3.31 to *** proposed LSTM-attention model can provide an effective prediction for attitude and position of shield machine in practical tunneling engineering.

关键词： LSTM Shield machine Attitude and position prediction Attention mechanism Tunnel excavation

Access to pyridines via cascade nucleophilic addition reaction of 1,2,3-triazines with activated ketones or acetonitriles

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Chinese Chemical Letters 2021年第1期32卷 393-396页

作者： Yuan Zhang han luo Qixing Lu Qiaoyu An You Li Shanshan Li Zongyuan Tang Baosheng Li School of Chemistry and Chemical Engineering Chongqing UniversityChongqing 400030China

We studied the cascade nucleophilic addition reactions of 1,2,3-triazines with activated acetonitriles or ketones,which were used to construct highly substituted pyridines that are not easily accessed by conventional *** strategy addressed some structural diversity issues currently facing medicinal chemistry,and the resulting pyridines could be used as convenient precursors for the synthesis of related *** particular,our method was applied to the syntheses of the marketed drug etoricoxib and several biologically important molecules in a few steps.

关键词： 1,2,3-Triazines Pyridines Nucleophilic addition Divergent synthesis Pharmaceuticals synthesis

ETC Proportional Adjustment Model Based on Queuing Theory in the Case of Unmanned Vehicles 36

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ETC Proportional Adjustment Model Based on Queuing Theory in...

SOURCES OF FOREIGN LANGUAGE ANXIETY:TOWARDS A FOUR-DIMENSION MODEL

第36届中国控制会议

作者： Junjie Zhu Haoyu Lin Yuting Xiao han luo Dongdong Liu Pengfei Li College of Electrical and Information Engineering Hunan University College of Mathematics and Econometrics Hunan University School of computer and information Fuyang Normal University College of Computer Science and Electronic Engineering Hunan University

ISBN: (纸本)9781538629185

With the continuous breakthroughs of unmanned vehicle technology,a increasing number of unmanned vehicles will be added to the current traffic *** will the above situation influence the traffic,and how will we change the existing traffic system design program to help unmanned technology to improve people’s travel efficiency in a better way,have become urgent problems to be *** this paper,the model of Queuing Theory is applied to simulate and calculate the number of lanes of different toll stations,on which basis,the optimal proportional adjustment model of ETC（Electronic Toll Collection） is ***,the results of sensitivity analysis of the model show that it has an excellent robustness and reliability.

关键词： queuing theory unmanned vehicle ETC

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当代外语研究 2012年第12期384卷 49-61页

作者： han luo Northwestern University

In the past three decades,the study of foreign language anxiety has attracted the attention of an increasing number of researchers and language *** in a variety of language learning contexts have found that approximately one-third of students studying a foreign language experience at least a moderate level of foreign language *** has also reported various types of negative effects of foreign language anxiety on foreign language *** foreign language anxiety is not only prevalent among language learners,but appears to interfere with language learning,it must be taken seriously in all types of language *** language teachers are interested in the causes of foreign language anxiety so that they can create more comfortable language learning *** sources of foreign language anxiety have been identified here and there across the literature,there has not been a systematic and comprehensive report of all the *** paper attempts to propose a four-dimension source model of foreign language anxiety based on a thorough literature review and the researcher' s own insights.

关键词：英语教学教学方法课堂教学阅读教学

Uncovering the oxidation mechanism of sphalerite(ZnS)in the absence and presence of water:A first-principles investigation

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International Journal of Mining Science and Technology 2025年第1期35卷 149-157页

作者： Yuanjia luo Wei Sun Haisheng han Jian Peng Feng Jiang School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083China

Herein,a first-principles investigation was innovatively conducted to research the surface oxidation of ZnS-like sphalerite in the absence and presence of H_(2)O .The findings showed that single O_(2) was preferred to be dissociated adsorption on sphalerite surface by generating SAO and Zn AO bonds,and the S atom on the surface was the most energy-supported site for O_(2) adsorption,on which a≡Zn-O-S-O-Zn≡structure will be ***,dissociated adsorption of single H_(2)O will not *** was preferred to be adsorbed on the top Zn atom on sphalerite surface in molecular form through Zn-O ***,sphalerite oxidation can occur as if O_(2) was present regardless of the presence of H_(2)O ,and when H_(2)O and O_(2) coexisted,the formation of sulfur oxide(SO_(2) )needed a lower energy barrier and it was easier to form on sphalerite surface than that only O_(2) *** the absence of H_(2)O ,when SO_(2) was generated,further oxidation of which would form neutral zinc *** the presence of H_(2)O ,the formation of SO_(2) on sphalerite surface was easier and the rate of further oxidation to form sulfate was also ***,the occurrence of sphalerite oxidation was accelerated.

关键词： First-principles Oxidation Sphalerite H_(2)O Lower energy barrier

Effect of Zirconium on Tensile Property,Microstructure and Fracture Behaviour of Cast Ni_(3)Al Based Alloy

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Journal of Iron and Steel Research International 1997年第1期4卷 37-41页

作者： Ye Wujun, Feng Di, han Guangwei, luo Heli Central Iron and Steel Research Institute, MMI, Beijing (100081), China Cent Iron & Steel Res Inst MMI Beijing 100081 Peoples R China

The effect of Zr on tensile property, microstructure and fracture behaviour of cast Ni 3Al based alloy strengthened with carbides has been studied. It was found that Zr distributes at interdendrites and grain boundaries in the form of ZrC particle and Ni 5Zr eutectic phase which can refine microstructure. Ni 5Zr phase can alleviate the crack initiation at grain boundaries and dendrite boundaries, which helps deformation to be harmonical between matrix and precipitates at elevated temperature.

关键词： Ni 3Al alloy tensile property fracture behaviour microstructure

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Counting of alpha particle tracks on imaging plate based on a convolutional neural network

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Nuclear Science and Techniques 2023年第3期34卷 52-63页

作者： Feng-Di Qin han-Yu luo Zheng-Zhong He Ke-Jun Lu Chuan-Gao Wang Meng-Meng Wu Zhong-Kai Fan Jian Shan School of Nuclear Science and Technology Hunan Provincial Key Laboratory of RadonUniversity of South ChinaHengyang 421001China School of Computer Science University of South ChinaHengyang 421001China China Institute of Atomic Energy Beijing 102413China

Imaging plates are widely used to detect alpha particles to track information,and the number of alpha particle tracks is affected by the overlapping and fading effects of the track *** this study,an experiment and a simulation were used to calibrate the efficiency parameter of an imaging plate,which was used to calculate the *** were created by using grayscale,which trained the convolutional neural network to count the alpha *** results demonstrated that the trained convolutional neural network can evaluate the alpha track counts based on the source and background images with a wider linear range,which was unaffected by the overlapping *** alpha track counts were unaffected by the fading effect within 60 min,where the calibrated formula for the fading effect was analyzed for 132.7 *** detection efficiency of the trained convolutional neural network for inhomogeneous ^(241)Am sources(2π emission)was 0.6050±0.0399,whereas the efficiency curve of the photo-stimulated luminescence method was lower than that of the trained convolutional neural network.

关键词： Imaging plate Convolutional neural network Alpha tracks counting