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Developing a Physiological Signal-Based, Mean Threshold and Decision-Level Fusion Algorithm (PMD) for Emotion Recognition

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Tsinghua Science and Technology 2023年第4期28卷 673-685页

作者： Qiuju zhang hongtao zhang Keming Zhou Le zhang College of Computer Science Sichuan UniversityChengdu 610065China August International Ltd. HoddesdonEN110EEUK Key Laboratory of Systems Health Science of Zhejiang Province Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China

With the development of computers,artificial intelligence,and cognitive science,engagement in deep communication between humans and computers has become increasingly ***,affective computing is a current hot research ***,this study constructs a Physiological signal-based,Mean-threshold,and Decision-level fusion algorithm(PMD)to identify human emotional ***,we select key features from electroencephalogram and peripheral physiological signals,and use the mean-value method to obtain the classification threshold of each participant and distinguish individual ***,we employ Gaussian Naive Bayes(GNB),Linear Regression(LR),Support Vector Machine(SVM),and other classification methods to perform emotion ***,we improve the classification accuracy by developing an ensemble *** experimental results reveal that physiological signals are more suitable for emotion recognition than classical facial and speech *** proposed mean-threshold method can solve the problem of individual differences to a certain extent,and the ensemble learning model we developed significantly outperforms other classification models,such as GNB and LR.

关键词： electroencephalogram(EEG) peripheral physiological signals machine learning emotion recognition multimodal fusion

Simulation of thermal expansion mismatch at high temperature

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Underground Space 2023年第1期8卷 210-228页

作者： Zhifei Gao Linbing Wang hongtao zhang National Center for Materials Service Safety University of Science and Technology BeijingBeijing 100083China Joint USTB-Virginia Tech Lab on Multifunctional Materials University of Science and Technology BeijingBeijing 100083China Joint USTB-Virginia Tech Lab on Multifunctional Materials Virginia TechBlacksburgVA 24061USA Department of Civil Engineering North China University of TechnologyBeijing 100144China

The thermal expansion mismatch between cement mortar and aggregate at high temperature is one of the main reasons causing the deterioration of concrete at high *** this study,the thermal damage of concrete caused by the thermal expansion mismatch between aggregate and cement mortar was investigated using a meso-scale concrete *** meso-scale concrete model is composed of mortar,aggregate and the interfacial transition zone(ITZ).Laboratory tests on the mechanical properties of cement mortar at high temperature were conducted to provide the necessary mechanical parameter for the meso-scale concrete *** simulation results show that the particle size,content,distribution and mechanical properties of the aggregate have an effect on the thermal damage of concrete at high *** smaller the particle size of concrete aggregate and the higher the elastic modulus of aggregate,the greater the damage of concrete under high *** to the increasing thermal expansion difference between aggregate and cement mortar,and the deterioration of the cement mortar with the increasing temperature,the damage of concrete increased sharply after 500℃.

关键词： Cement mortar Concrete High temperature Thermal expansion mismatch Meso-scale model

Characteristics of vascular lesions in patients with posterior circulation infarction according to age and region of infarct

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Neural Regeneration Research 2012年第32期7卷 2536-2541页

作者： Daopei zhang Shuling zhang hongtao zhang Yuming Xu Third Department of Neurology Zhengzhou People's Hospital Zhengzhou 450003 Henan Province China Third Department of Neurology First Affiliated Hospital Zhengzhou University Zhengzhou 450052 Henan Province China

Patients with posterior circulation infarction underwent CT angiography and magnetic resonance angiography. Intracranial and extracranial vasculopathy was evaluated according to age group and location of stroke. Patients aged 〉 60 years and 〈 60 years had similar rates of vertebral artery dominance and vertebrobasilar artery developmental or origin anomalies. Vertebrobasilar artery stenosis or occlusion and tortuosity occurred more frequently in patients aged 〉 60 years than 〈 60 years. The rates of vertebrobasilar artery anomalies and tortuosity were high in patients with posterior circulation infarction. Vertebrobasilar artery tortuosity occurred more frequently in patients aged 〉 60 years, whereas vertebrobasilar artery developmental anomalies occurred with similar frequency in patients aged 〈 60 years and 〉 60 years. Patients with infarction of the brainstem or cerebellum were more ~ikely to have vertebral artery stenosis or occlusion, basi^ar artery stenosis or occlusion, vertebral artery dominance or tortuosity, and basilar artery tortuosity, and patients with infarction of the thalamus, medial temporal, or occipital lobes were more likely to have stenosis or occlusion of the vertebral or basilar arteries. Vertebrobasilar artery tortuosity, vertebral artery dominance （hypoplasia）, and congenital variations of the vertebrobasilar system may lead to posterior circulation infarction at different locations in different age groups.

关键词： vertebrobasilar artery vertebral artery acute cerebral infarction artery tortuosity magnetic resonance angiography CT angiography neuroimaging neural regeneration

Rapid design of secondary deformation-aging parameters for ultra-low Co content Cu-Ni-Co-Si-X alloy via Bayesian optimization machine learning

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International Journal of Minerals,Metallurgy and Materials 2022年第6期29卷 1197-1205页

作者： hongtao zhang Huadong Fu Yuheng Shen Jianxin Xie Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing 100083China Key Laboratory for Advanced Materials Processing(MOE) University of Science and Technology BeijingBeijing 100083China Beijing Laboratory of Metallic Materials and Processing for Modern Transportation University of Science and Technology BeijingBeijing 100083China

It is difficult to rapidly design the process parameters of copper alloys by using the traditional trial-and-error method and simultaneously improve the conflicting mechanical and electrical *** purpose of this work is to develop a new type of Cu-Ni-Co-Si alloy saving scarce and expensive Co element,in which the Co content is less than half of the lower limit in ASTM standard C70350 alloy,while the properties are as the same level as C70350 *** we adopted a strategy combining Bayesian optimization machine learning and experimental iteration and quickly designed the secondary deformation-aging parameters(cold rolling deformation 90%,aging temperature 450℃,and aging time 1.25 h)of the new copper alloy with only 32 experiments(27 basic sample data acquisition experiments and 5 iteration experiments),which broke through the barrier of low efficiency and high cost of trial-and-error design of deformation-aging parameters in precipitation strengthened copper *** experimental hardness,tensile strength,and electrical conductivity of the new copper alloy are HV(285±4),(872±3)MPa,and(44.2±0.7)%IACS(international annealed copper standard),reaching the property level of the commercial lead frame C70350 *** work provides a new idea for the rapid design of material process parameters and the simultaneous improvement of mechanical and electrical properties.

关键词： copper alloy process design machine learning Bayesian optimization utility function

Preparation of graphene-based active carbons from petroleum asphalt for high-performance supercapacitors without added conducting materials

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Science China(Technological Sciences) 2022年第12期65卷 2866-2873页

作者： WANG Bin XIE PengYi zhang Miao zhang hongtao CHEN YongSheng School of Physics and Materials Science Guangzhou UniversityGuangzhou 510006China School of Chemistry and Materials Science Guangdong University of EducationGuangzhou 510303China The Centre of Nanoscale Science and Technology and Key Laboratory of Functional Polymer Materials Institute of Polymer ChemistryCollege of ChemistryNankai UniversityTianjin 300071China Research Center for Advanced Information Materials(CAIM) Huangpu Research&Graduate School of Guangzhou UniversityGuangzhou 510555China

Graphene-based active carbons(G-ACs) with a high specific surface area and high conductivity are promising electrode materials for high-performance supercapacitors. Typically, however, syntheses of the G-ACs call for expensive raw materials and are cumbersome. Here, the G-ACs are obtained by direct chemical activation of petroleum asphalt. The highest specific surface area of the prepared G-ACs is 3505 m^(2)/g and the corresponding conductivity is 32 S/m. Electrodes fabricated using the as-prepared G-ACs, i.e., without any conductive additives, demonstrate high specific capacitance and high rate performance. The specific capacitances of optimized G-ACs, as measured in a 1 mol/L TEABF_(4)/AN electrolyte and the neat ionic liquid EMIMBF_(4), are 155 and 176 F/g at 1 A/g, providing the high energy density of 39.2 and 74.9 W h/kg, respectively. In addition,the G-ACs exhibited excellent rate capability with a negligible capacitance decay from 0.5 to 10 A/g in both 1 mol/L TEABF_(4)/AN and neat EMIMBF_(4) electrolytes. Furthermore, the optimized G-AC has a high energy density(68.5 W h/kg) at a relatively high power density(8501 W/kg), indicating that it holds potential for application in green energy storage.

关键词： supercapacitor asphalt porous carbon rate capability

A LOWER BOUND LIMIT ANALYSIS OF DUCTILE COMPOSITE MATERIALS

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Acta Mechanica Solida Sinica 2005年第3期18卷 215-224页

作者： zhang hongtao Liu Yinghua Xu Bingye Department of Engineering Mechanics FML Tsinghua University Beijing 100084 China

The plastic load-bearing capacity of ductile composites such as metal matrix composites is studied with an insight into the microstructures. The macroscopic strength of a composite is obtained by combining the homogenization theory with static limit analysis, where the temperature parameter method is used to construct the self-equilibrium stress field. An interface failure model is proposed to account for the effects of the interface on the failure of composites. The static limit analysis with the finite-element method is then formulated as a constrained nonlinear programming problem, which is solved by the Sequential Quadratic Programming （SQP） method. Finally, the macroscopic transverse strength of perforated materials, the macroscopic transverse and off-axis strength of fiber-reinforced composites are obtained through numerical calculation. The computational results are in good agreement with the experimental data.

关键词： limit analysis homogenization theory interface failure temperature parameter method

Functional recovery and microenvironmental alterations in a rat model of spinal cord injury following human umbilical cord blood-derived mesenchymal stem cells transplantation

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Neural Regeneration Research 2010年第3期5卷 165-170页

作者： hongtao zhang Huilin Yang Huanxiang zhang Jing Qu Department of Orthopedics First Affiliated Hospital of Soochow University Suzhou 215007 Jiangsu Province China Department of Cell Biology Medical College of Soochow University Suzhou 215123 Jiangsu Province China Key Laboratory of Stem Cell Research of Jiangsu Province Suzhou 215000 Jiangsu Province China

BACKGROUND： Transplantation of human umbilical cord blood-derived mesenchymal stem cells （MSCs） has been shown to benefit spinal cord injury （SCI） repair. However, mechanisms of microenvironmental regulation during differentiation of transplanted MSCs remain poorly understood. OBJECTIVE： To observe changes in nerve growth factor （NGF）, brain-derived neurotrophic factor （BDNF）, and interleukin-8 （IL-8） expression following transplantation of human umbilical cord-derived MSCs, and to explore the association between microenvironment and neural functional recovery following MSCs transplantation. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Department of Orthopedics, First Affiliated Hospital of Soochow University from April 2005 to March 2007. MATERIALS： Human cord blood samples were provided by the Department of Gynecology and Obstetrics, First Affiliated Hospital of Soochow University. Written informed consent was obtained. METHODS： A total of 62 Wister rats were randomly assigned to control （n = 18）, model （n = 22, SCI ＋ PBS）, and transplantation （n = 22, SCI ＋ MSCs） groups. The rat SCI model was established using the weight compression method. MSCs were isolated from human umbilical cord blood and cultured in vitro for several passages. 5-bromodeoxyuridine （BrdU）-Iabeled MSCs （24 hours before injection） were intravascularly transplanted. MAIN OUTCOME MEASURES： The rats were evaluated using the Basso, Beattie and Bresnahan （BBB） locomotor score and inclined plane tests. Transplanted cells were analyzed following immunohistochemistry. Enzyme-linked immunosorbant assay was performed to determine NGF, BDNF, and IL-8 levels prior to and after cell transplantation. RESULTS： A large number of BrdU-positive MSCs were observed in the SCI region of the transplantation group, and MSCs were evenly distributed in injured spinal cord tissue 1 week after transplantation. BBB score and inclined plane test results revealed significant fu

关键词： human umbilical cord blood-derived mesenchymal stem cells nerve growth factor brain-derived neurotrophic factor interleukin-8 spinal cord injury neural stem cells neural regeneration

PLASTIC LIMIT ANALYSIS OF DUCTILE COMPOSITE STRUCTURES FROM MICRO-TO MACRO-MECHANICAL ANALYSIS

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Acta Mechanica Solida Sinica 2009年第1期22卷 73-84页

作者： hongtao zhang Yinghua Liu Binge Xu Department of Civil Engineering University of Science and Technology Beijing Beijing 100083 China Department of Engineering Mechanics Tsinghua University Beijing 100084 China

The load-bearing capacity of ductile composite structures comprised of periodic composites is studied by a combined micro/macromechanicai approach. Firstly, on the microscopic level, a representative volume element （RVE） is selected to reflect the microstructures of the composite materials and the constituents are assumed to be elastic perfectly-plastic. Based on the homogenization theory and the static limit theorem, an optimization formulation to directly calculate the macroscopic strength domain of the RVE is obtained. The finite element modeling of the static limit analysis is formulated as a nonlinear mathematical programming and solved by the sequential quadratic programming method, where the temperature parameter method is used to construct the self-stress field. Secondly, Hill＇s yield criterion is adopted to connect the micromechanicai and macromechanical analyses. And the limit loads of composite structures are worked out on the macroscopic scale. Finally, some examples and comparisons are shown.

关键词： periodic composites limit analysis homogenization micro/macromechanics

Improved Data Stream Clustering Method: Incorporating KD-Tree for Typicality and Eccentricity-Based Approach

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Computers, Materials & Continua 2024年第2期78卷 2557-2573页

作者： Dayu Xu Jiaming Lu Xuyao zhang hongtao zhang College of Mathematics and Computer Science Zhejiang A&F UniversityHangzhou311300China College of Economics and Management Zhejiang A&F UniversityHangzhou311300China

Data stream clustering is integral to contemporary big data ***,addressing the ongoing influx of data streams efficiently and accurately remains a primary challenge in current *** paper aims to elevate the efficiency and precision of data stream clustering,leveraging the TEDA(Typicality and Eccentricity Data Analysis)algorithm as a foundation,we introduce improvements by integrating a nearest neighbor search algorithm to enhance both the efficiency and accuracy of the *** original TEDA algorithm,grounded in the concept of“Typicality and Eccentricity Data Analytics”,represents an evolving and recursive method that requires no prior *** the algorithm autonomously creates and merges clusters as new data arrives,its efficiency is significantly hindered by the need to traverse all existing clusters upon the arrival of further *** work presents the NS-TEDA(Neighbor Search Based Typicality and Eccentricity Data Analysis)algorithm by incorporating a KD-Tree(K-Dimensional Tree)algorithm integrated with the Scapegoat *** arrival,this ensures that new data points interact solely with clusters in very close *** significantly enhances algorithm efficiency while preventing a single data point from joining too many clusters and mitigating the merging of clusters with high overlap to some *** apply the NS-TEDA algorithm to several well-known datasets,comparing its performance with other data stream clustering algorithms and the original TEDA *** results demonstrate that the proposed algorithm achieves higher accuracy,and its runtime exhibits almost linear dependence on the volume of data,making it more suitable for large-scale data stream analysis research.

关键词： Data stream clustering TEDA KD-tree scapegoat tree