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A probabilistic generative model for tracking multi-knowledge concept mastery probability

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Frontiers of Computer Science 2024年第3期18卷 155-170页

作者： Hengyu LIU Tiancheng zhang Fan LI Minghe yu Ge yu School of Computer Science and Engineering Northeastern UniversityShenyang 110169China Software College Northeastern UniversityShenyang 110169China

Knowledge tracing aims to track students’knowledge status over time to predict students’future performance *** a real environment,teachers expect knowledge tracing models to provide the interpretable result of knowledge *** chain-based knowledge tracing(MCKT)models,such as Bayesian Knowledge Tracing,can track knowledge concept mastery probability over ***,as the number of tracked knowledge concepts increases,the time complexity of MCKT predicting student performance increases exponentially(also called explaining away problem).When the number of tracked knowledge concepts is large,we cannot utilize MCKT to track knowledge concept mastery probability over *** addition,the existing MCKT models only consider the relationship between students’knowledge status and problems when modeling students’responses but ignore the relationship between knowledge concepts in the same *** address these challenges,we propose an inTerpretable pRobAbilistiC gEnerative moDel(TRACED),which can track students’numerous knowledge concepts mastery probabilities over *** solve explain away problem,we design long and short-term memory(LSTM)-based networks to approximate the posterior distribution,predict students’future performance,and propose a heuristic algorithm to train LSTMs and probabilistic graphical model *** better model students’exercise responses,we proposed a logarithmic linear model with three interactive strategies,which models students’exercise responses by considering the relationship among students’knowledge status,knowledge concept,and *** conduct experiments with four real-world datasets in three knowledge-driven *** experimental results show that TRACED outperforms existing knowledge tracing methods in predicting students’future performance and can learn the relationship among students,knowledge concepts,and problems from students’exercise *** also conduct several case *** case studies show that

关键词： probabilistic graphical model deep learning knowledge tracing learner modeling

Ignition processes and characteristics of charring conductive polymers with a cavity geometry in precombustion chamber for applications in micro/nano satellite hybrid rocket motors

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Defence Technology（防务技术） 2024年第2期32卷 55-66页

作者： Zhiyuan zhang Hanyu Deng Wenhe Liao Bin yu Zai yu Nanjing University of Science and Technology Nanjing 210094China

The arc ignition system based on charring polymers has advantages of simple structure,low ignition power consumption and multiple ignitions,which bringing it broadly application prospect in hybrid propulsion system of micro/nano ***,charring polymers alone need a relatively high input voltage to achieve pyrolysis and ignition,which increases the burden and cost of the power system of micro/nano satellite in practical *** conductive substance into charring polymers can effectively decrease the conducting voltage which can realize low voltage and low power consumption repeated ignition of arc ignition *** this paper,a charring conductive polymer ignition grain with a cavity geometry in precombustion chamber,which is composed of PLA and multiwall carbon nanotubes(MWCNT)was *** detailed ignition processes were analyzed and two different ignition mechanisms in the cavity of charring conductive polymers were *** ignition characteristics of charring conductive polymers were also investigated at different input voltages,ignition grain structures,ignition locations and injection schemes in a visual ignition *** results demonstrated that the ignition delay and external energy required for ignition were inversely correlated with the voltages applied to ignition ***,the incremental depth of cavity shortened the ignition delay and external energy required for ignition while accelerated the propagation of *** the depth of cavity increased from 2 to 6 mm(at 50 V),the time of flame propagating out of ignition grain changed from 235.6 to 108 ms,and values of mean ignition delay time and mean external energy required for ignition decreased from 462.8 to 320 ms and 16.2 to 10.75 J,*** rear side of the cavity was the ideal ignition position which had a shorter ignition delay and a faster flame propagation speed in comparison to other ignition *** to direct injection scheme,swirlin

关键词： Micro/nano satellite hybrid propulsion Arc ignition Charring conductive polymer Ignition mechanism Ignition characteristic Repeated ignition

Heat Transfer Characteristics of a Microchannel Heat Sink with Highly-Dense Micro-Jet Arrays

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Journal of Thermal Science 2024年第3期33卷 1148-1160页

作者： zhang yu CHEN Xiaoyan MIAO Lin CHEN Liang HOU yu State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an710049China Beijing Aerospace Technology Institute Beijing100083China

This paper proposed a new structure of highly-dense micro-jet arrays for hybrid jet-impingement/microchannel heat sinks(~120 jet per cm^(2) with jet width of 0.35 mm).Parametric study is performed to investigate the influence of structure and flow parameters on the convective heat transfer of water jet cooling in confined *** simulation results show that the optimal jet width,jet spacing and impingement distance are around 0.2 mm,0.2 mm and 0.3 mm,respectively,which can achieve a low thermal resistance as well as a relatively low pressure *** analysis of the heat transfer pathways shows that the micro-fin jet structures can extend the impinging heat transfer area and conduct a considerable proportion of heat,which can reach up to 38.9%with the Reynolds number ranging from 797.1 to *** heat transfer characteristics in the heat sink will shift from impingement dominated heat transfer to the channel-convection dominated heat transfer as the jet impingement distance increases.A correlation is proposed to predict the average Nusselt number on the stagnation area for the heat sink with different structure parameters,and the deviations of predictions from the numerical results are less than 10%.

关键词： hybrid heat sink impingement microchannel thermal management high heat flux

BLS-identification:A device fingerprint classification mechanism based on broad learning for Internet of Things

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Digital Communications and Networks 2024年第3期10卷 728-739页

作者： yu zhang Bei Gong Qian Wang Faculty of Information Technology Beijing University of TechnologyBeijing100124China School of Information Science and Technology Zhengzhou Normal UniversityHenan450044China

The popularity of the Internet of Things(IoT)has enabled a large number of vulnerable devices to connect to the Internet,bringing huge security *** a network-level security authentication method,device fingerprint based on machine learning has attracted considerable attention because it can detect vulnerable devices in complex and heterogeneous access ***,flexible and diversified IoT devices with limited resources increase dif-ficulty of the device fingerprint authentication method executed in IoT,because it needs to retrain the model network to deal with incremental features or *** address this problem,a device fingerprinting mechanism based on a Broad Learning System(BLS)is proposed in this *** mechanism firstly characterizes IoT devices by traffic analysis based on the identifiable differences of the traffic data of IoT devices,and extracts feature parameters of the traffic packets.A hierarchical hybrid sampling method is designed at the preprocessing phase to improve the imbalanced data distribution and reconstruct the fingerprint *** complexity of the dataset is reduced using Principal Component Analysis(PCA)and the device type is identified by training weights using *** experimental results show that the proposed method can achieve state-of-the-art accuracy and spend less training time than other existing methods.

关键词： Device fingerprint Traffic analysis Class imbalance Broad learning system Access authentication

Global epidemiology of mental disorder in atrial fibrillation between 1998-2021:A systematic review and meta-analysis

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World Journal of Psychiatry 2024年第1期14卷 179-193页

作者： Shuai zhang Na zhang Liu Liu Wang Zheng zi-Lin Ma Si-yu Qiao Ying-Li Zhao Yi-Hong Wei Gang Wu Qiu-Ting yu Bing Deng Lin Shen Department of Cardiology LongHua Hospital Shanghai University of Traditional Chinese MedicineShanghai 200032China Department of Dermatology Yueyang Hospital of Integrated Traditional Chinese and Western MedicineShanghai University of Traditional Chinese MedicineShanghai 200437China

BACKGROUND As the burden of mental disorders among patients with atrial fibrillation(AF)increases,researchers are beginning to pay close attention to the risk and prevalence of these *** studies have independently analyzed the risk of comorbidity with depression and anxiety in patients with AF,no study has systematically focused on the global epidemiology of these two mental *** To explore the prevalence of depression and anxiety in patients with *** Five databases were searched from their date of establishment until January *** studies reporting the comorbidity of AF with depression and anxiety,were included in this *** information,such as the first author/publication year,study year,study type,and prevalence of depression and anxiety,were *** SE 15.1 was used to analyze the ***,meta-regression,and sensitivity analyses were performed to estimate study *** After a thorough search,26 studies were identified and included in this *** prevalence rates of depression and anxiety in adults with AF were 24.3%and 14.5%,*** adult males with AF,the prevalence was 11.7%and 8.7%,respectively,whereas in females it was 19.8%and 10.1%,*** older adults with AF,the prevalence rates of depression and anxiety were 40.3%and 33.6%,*** highest regional prevalence of depression and anxiety was observed in European(30.2%)and North American(19.8%)patients with *** In this study,we found that the prevalence of depression and anxiety among patients with AF varies with sex,region,and evaluation scales,suggesting the need for psychological interventions for patients with AF in clinical practice.

关键词： Atrial fibrillation Depression Anxiety Prevalence

scRNA-seq reveals that origin recognition complex subunit 6 regulates mouse spermatogonial cell proliferation and apoptosis via activation of Wnt/β-catenin signaling

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Asian Journal of Andrology 2024年第1期26卷 46-56页

作者： Shi-Wei Liu Jia-Qiang Luo Liang-yu Zhao Ning-Jing Ou Chao-Yang yu-Xiang zhang Hao-Wei Bai Hong-Fang Sun Jian-Xiong zhang Chen-Cheng Yao Peng Li Ru-Hui Tian Zheng Li zi-Jue Zhu Department of Andrology Center for Men's HealthUrologic Medical CenterShanghai General HospitalShanghai Jiao Tong University School of MedicineShanghai 200080China State Key Lab of Reproductive Medicine Nanjing Medical UniversityNanjing 211166China Shanghai Key Lab of Reproductive Medicine Shanghai Jiao Tong University School of MedicineShanghai 200080China Department of Urology Guangdong Provincial Key Laboratory of Biomedical ImagingThe Fifth Affiliated HospitalSun Yat-sen UniversityZhuhai 519000China Department of Urology First Affiliated Hospital of Nanjing Medical UniversityNanjing 210029China

The regulation of spermatogonial proliferation and apoptosis is of great significance for maintaining *** single-cell RNA sequencing(scRNA-seq)analysis of the testis was performed to identify genes upregulated in *** scRNAseq analysis,we identified the spermatogonia upregulated gene origin recognition complex subunit 6(Orc6),which is involved in DNA replication and cell cycle regulation;its protein expression in the human and mouse testis was detected by western blot and *** explore the potential function of Orc6 in spermatogonia,the C18-4 cell line was transfected with control or Orc6 ***,5-ethynyl-2-deoxyuridine(EdU)and terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL)assays,flow cytometry,and western blot were used to evaluate its effects on proliferation and *** was revealed that ORC6 could promote proliferation and inhibit apoptosis of C18-4 *** RNA sequencing and bioinformatics analysis indicated that Orc6 was involved in the activation of wingless/integrated(Wnt)/β-catenin *** blot revealed that the expression ofβ-catenin protein and its phosphorylation(Ser675)were significantly decreased when silencing the expression of *** findings indicated that Orc6 was upregulated in spermatogonia,whereby it regulated proliferation and apoptosis by activating Wnt/β-catenin signaling.

关键词： cell proliferation ORCG scRNA-seq analysis spermatogonia Wnt/β-catenin signaling

Ruxolitinib improves the inflammatory microenvironment,restores glutamate homeostasis,and promotes functional recovery after spinal cord injury

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Neural Regeneration Research 2024年第11期19卷 2499-2512页

作者： Jiang Cao Xiao yu Jingcheng Liu Jiaju Fu Binyu Wang Chaoqin Wu Sheng zhang Hongtao Chen zi Wang Yinyang Xu Tao Sui Jie Chang Xiaojian Cao Department of Orthopedics The First Affiliated Hospital of Nanjing Medical UniversityNanjingJiangsu ProvinceChina Department of Trauma Surgery Subei People’s Hospital of JiangsuClinical Medical College of Yangzhou UniversityYangzhouJiangsu ProvinceChina Department of Orthopedics Zhongda HospitalSoutheast UniversityNanjingJiangsu ProvinceChina Department of Orthopedic Surgery Nanjing Drum Tower HospitalThe Affiliated Hospital of Medical School of Nanjing UniversityNanjingJiangsu ProvinceChina

The inflammatory microenvironment and neurotoxicity can hinder neuronal regeneration and functional recovery after spinal cord ***,a JAK-STAT inhibitor,exhibits effectiveness in autoimmune diseases,arthritis,and managing inflammatory cytokine *** studies have shown the neuroprotective potential of ruxolitinib in neurological trauma,the exact mechanism by which it enhances functional recovery after spinal cord injury,particularly its effect on astrocytes,remains *** address this gap,we established a mouse model of T10 spinal cord contusion and found that ruxolitinib effectively improved hindlimb motor function and reduced the area of spinal cord *** sequencing analysis showed that ruxolitinib alleviated inflammation and immune response after spinal cord injury,restored EAAT2 expression,reduced glutamate levels,and alleviated excitatory ***,ruxolitinib inhibited the phosphorylation of JAK2 and STAT3 in the injured spinal cord and decreased the phosphorylation level of nuclear factor kappa-B and the expression of inflammatory factors interleukin-1β,interleukin-6,and tumor necrosis factor-α.Additionally,in glutamate-induced excitotoxicity astrocytes,ruxolitinib restored EAAT2 expression and increased glutamate uptake by inhibiting the activation of STAT3,thereby reducing glutamate-induced neurotoxicity,calcium influx,oxidative stress,and cell apoptosis,and increasing the complexity of dendritic ***,these results indicate that ruxolitinib restores glutamate homeostasis by rescuing the expression of EAAT2 in astrocytes,reduces neurotoxicity,and effectively alleviates inflammatory and immune responses after spinal cord injury,thereby promoting functional recovery after spinal cord injury.

关键词： astrocytes EAAT2 excitotoxicity glutamate homeostasis JAK-STAT pathway locomotor function neurotoxicity ruxolitinib spinal cord injury transcriptome analysis

TMEM63B regulates postnatal development of cochlear sensory epithelia via thyroid hormone signaling

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Journal of Genetics and Genomics 2024年第6期51卷 673-676页

作者： Chang Ye Tian-zi zhang Yan-yu Zang yun Stone Shi Guoqiang Wan State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animal for Disease Study Model Animal Research CenterMedical SchoolNanjing UniversityNanjingJiangsu 210032China Guangdong Institute of Intelligence Science and Technology ZhuhaiGuangdong 519031China

Sound transmission occurs in the cochlea,a complex and ingenious subdivision in the inner *** structure of the cochlea develops structurally and functionally by the time before two postnatal weeks(the time of hearing onset)in mice(Geal-Dor et al.,1993).Greater epithelial ridge(GER,also known as Kolliker's organ)is a transient cochlear structure containing a group of columnar epithelial supporting cells surrounding the inner hair cells(IHCs).

关键词： cochlear al. supporting

Intelligent geochemical interpretation of mass chromatograms:Based on convolution neural network

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Petroleum Science 2024年第2期21卷 752-764页

作者： Kai-Ming Su Jun-Gang Lu Jian yu zi-Xing Lu Shi-Jia Chen Hubei Key Laboratory of Petroleum Geochemistry and Environment Wuhan430100HubeiChina College of Resources and Environment Yangtze UniversityWuhan430100HubeiChina School of Geoscience and Technology Southwest Petroleum UniversityChengdu610500SichuanChina Changqing Oilfield Company PetroChinaXi'an710021ShaanxiChina

Gas chromatography-mass spectrometry(GC-MS)is an extremely important analytical technique that is widely used in organic *** is the only approach to capture biomarker features of organic matter and provides the key evidence for oil-source correlation and thermal maturity ***,the conventional way of processing and interpreting the mass chromatogram is both timeconsuming and labor-intensive,which increases the research cost and restrains extensive applications of this *** overcome this limitation,a correlation model is developed based on the convolution neural network(CNN)to link the mass chromatogram and biomarker features of samples from the Triassic Yanchang Formation,Ordos Basin,*** this way,the mass chromatogram can be automatically *** research first performs dimensionality reduction for 15 biomarker parameters via the factor analysis and then quantifies the biomarker features using two indexes(*** and PMI)that represent the organic matter thermal maturity and parent material type,***,training,interpretation,and validation are performed multiple times using different CNN models to optimize the model structure and hyper-parameter setting,with the mass chromatogram used as the input and the obtained MI and PMI values for supervision(label).The optimized model presents high accuracy in automatically interpreting the mass chromatogram,with R2values typically above 0.85 and0.80 for the thermal maturity and parent material interpretation results,*** significance of this research is twofold:(i)developing an efficient technique for geochemical research;(ii)more importantly,demonstrating the potential of artificial intelligence in organic geochemistry and providing vital references for future related studies.

关键词： Organic geochemistry Biomarker Mass chromatographic analysis Automated interpretation Convolution neural network Machine learning