检索结果-南通市图书馆

自动化学报 2012年第7期 1225-1228页

作者：徐宗本郭海亮王尧张海 institute of Information and system Science Xi’an Jiaotong University Department of Mathematics Northwest University

Recently, regularization methods have attracted increasing attention. Lq (0 < q < 1) regularizations were proposed after L1 regularization for better solution of sparsity problems. A natural question is which is the best choice among Lq regularizations with all q in (0, 1)? By taking phase diagram studies with a set of experiments implemented on signal recovery and error correction problems, we show the following: 1) As the value of q decreases, the Lq regularization generates sparser solution. 2) When 1/2 ≤ q < 1, the L1/2 regularization always yields the best sparse solution and when 0 < q ≤ 1/2, the performance of the regularizatons takes no significant difference. Accordingly, we conclude that the L1/2 regularization can be taken as a rep- resentative of Lq (0 < q < 1) regularizations.

关键词： Lq regularization phase diagram signal recovery error correction

Brain endothelial cyclic GMP-AMP synthase(cGAS)-stimulator of interferon genes(STING)signaling pathway in aging and neurodegeneration

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第7期20卷 2005-2007页

作者： Bryan Sun Lulin Li Jian Luo Palo Alto Veterans institute for Research VA Palo Alto Health Care SystemPalo AltoCAUSA Polytrauma system of Care VA Palo Alto Health Care SystemPalo AltoCAUSA

The cyclic GMP-AMP synthase(cGAS)-stimulator of interferon genes(STING)signaling pathway has emerged as a key mediator of *** current studies primarily attribute its effects to neurons and glial cells,emerging research suggests that cGAS-STING signaling may play a critical role in cerebral vasculature,particularly in brain endothelial ***,studying the role 7of inflammation caused by the cGAS-STING pathway in brain endothelial cells could provide a more comprehensive understanding of neuroinflammatory disease and new avenues for therapeutic ***,we review the multifaceted role of global cGAS-STING signaling in various neurological and neuroinflammatory diseases and the potential contribution of cGAS-STING in brain endothelial cells.

关键词： stimulator interferon inflammation

Leader-follower: Human-centered intention-guided controller for novel SuperLimb with application to load-carrying scenarios

在线全文

学校读者我要写书评

暂无评论

Science China Technological Sciences 2025年第1期 325-338页

作者： Qinghua ZHANG Xianglong LI Hongwei JING Kerui SUN Yuancheng LI Sikai ZHAO Lele LI Haotian JU Ziqi WANG Rui WU Tianjiao ZHENG Jie ZHAO Yanhe ZHU The State Key Laboratory of Robotics and system Harbin Institute of Technology The Learning Algorithms and systems Laboratory School of Engineeringécole Polytechnique Fédérale de Lausanne

Supernumerary robotic arms(SuperLimb) are a new type of wearable robot that works closely with humans as a third hand to augment human operation capability. Accurate conveyance of wearers' intentions, allocation of roles, and humancentered interaction considerations are the key points in the process of human–SuperLimb collaboration. This paper proposes a human-centered intention-guided leader–follower controller that relies on the dynamic modeling of SuperLimb with application to load-carrying scenarios. The proposed leader–follower controller takes the human as the leader and the SuperLimb as the follower, achieving effective information communication, autonomous coordination, and good force compliance between SuperLimb, humans, and the environment under human safety assurance. First, the human–SuperLimb dynamic system is modeled to achieve force interaction with the environment and wearer. Second, to achieve the precise intention extraction of humans, pose data from five visual odometry sensors are fused to capture the human state, the generalized position, the velocity of hands, and the surface electromyography signals from two myoelectric bracelets sensors are processed to recognize the natural hand gestures during load-carrying scenarios by a designed Swin transformer network. Then, based on the real-time distance detection between human and mechanical limbs, the security assurance and force-compliant interaction of the human–SuperLimb system are realized. Finally, the human hand muscle intention recognition, human–robot safety strategy verification,and comparative load-carrying experiments with and without the proposed method are conducted on the SuperLimb *** showed that the task parameters are well estimated to produce more reasonable planning trajectories, and SuperLimb could well understand the wearer's intentions to switch different SuperLimb actions. The proposed sensor-based human–robot communication framework motivates future studies of o

关键词：

Constraints on what controls millennial-scale basin-wide denudation across mountain belts, Asia

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2025年第1期 74-93页

作者： Ye YANG Steven A.BINNIE Sheng XU Cong-Qiang LIU Tibor J.DUNAI institute of Surface-Earth system Science School of Earth System Science Tianjin University institute of Geology and Mineralogy University of Cologne

The terrestrial cosmogenic nuclide dataset consisting of 123310Be measurements of fluvial sediment samples across the Asian mountain belts is used to constrain the influence of climate,tectonics and topography on Earth-surface denudation processes.10Be-derived basin-wide denudation rates were recalculated using a Monte Carlo simulation approach that relied on pixel-by-pixel production *** rates derived span four orders of magnitude,from 7.4±0.7 mm kyr-1（1σ;Central Tibetan Plateau） to 9,646744+777mm kyr-1（1σ;Southern Tibetan Plateau）,with a median of 186 mm *** our results with the traditional basin-wide production rate scaling model using a centroid coordinate and mean elevation,suggests that 96.6%of production rates will be underestimated using the latter method,especially for basins with a large *** bias between both methods reaches as large as 40%,caused by basin hypsometry and the nonlinear scaling of production rate with elevation and *** of the correlations between uniformly recalculated denudation rates and tectonics,climate,topography and rock lithology will facilitate the extrapolation of denudation rates in unknown basins using available *** the perspective of local scales,precipitation coupled with neotectonics-driven landslides is likely the most influential factor in subtropical Taiwan Island,while topography primarily constrains surface denudation rates in the eastern Tibetan Plateau within a narrow range of *** highland regions with glacier coverage,such as the Pamir,central and southern Tibetan Plateau high denudation rates are affected by glaciation,whereas lower precipitation and high erosion base level may limit river incision and evolving relief in the Central Tibetan *** contrast to local-scale findings highlighting a dominant factor constraining denudation rate,our large-scale quantitative analyses across the Asian mountain belts finds that （1） topographic metrics including

关键词：

A Novel Model for Describing Rail Weld Irregularities and Predicting Wheel-Rail Forces Using a Machine Learning Approach

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2025年第1期142卷 555-577页

作者： Linlin Sun Zihui Wang Shukun Cui Ziquan Yan Weiping Hu Qingchun Meng State Key Laboratory of High-Speed Railway Track system China Academy of Railway Sciences Corporation LimitedBeijing100081China Railway Engineering Research institute China Academy of Railway Sciences Corporation LimitedBeijing100081China School of Aeronautic Science and Engineering Beihang UniversityBeijing100191China

Rail weld irregularities are one of the primary excitation sources for vehicle-track interaction dynamics in modern high-speed *** can cause significant wheel-rail dynamic interactions,leading to wheel-rail noise,component damage,and *** researchers have employed the vehicle-track interaction dynamic model to study the dynamic interactions between wheel and rail induced by rail weld geometry ***,the cosine wave model used to simulate rail weld irregularities mainly focuses on the maximum value and neglects the geometric *** this study,novel theoretical models were developed for three categories of rail weld irregularities,based on measurements of the high-speed railway from Beijing to *** vertical dynamic forces in the time and frequency domains were compared under different running *** forces generated by the rail weld irregularities that were measured and modeled,respectively,were compared to validate the accuracy of the proposed ***,based on the numerical study,the impact force due to rail weld irrregularity is modeled using an Artificial Neural Network(ANN),and the optimum combination of parameters for this model is *** results showed that the proposed model provided a more accurate wheel/rail dynamic evaluation caused by rail weld irregularities than that established in the *** ANN model used in this paper can effectively predict the impact force due to rail weld irrregularity while reducing the computation time.

关键词： Rail weld irregularity high-speed railway vehicle-track coupled dynamics wheel/rail dynamic vertical force artificial neural networks

Multi-Scale Dilated Convolution Network for SPECT-MPI Cardiovascular Disease Classification with Adaptive Denoising and Attenuation Correction

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2025年第1期142卷 299-327页

作者： A.Robert Singh Suganya Athisayamani Gyanendra Prasad Joshi Bhanu Shrestha Department of Computational Intelligence SRM Institute of Science and TechnologyKattankulathur603203Tamil NaduIndia School of Computing Sastra Deemed to be UniversityThanjavur613401Tamil NaduIndia Department of Artificial Intelligence&Software Kangwon National UniversitySamcheok25913Republic of Korea Department of Information Convergence system Graduate School of Smart ConvergenceKwangwoon UniversitySeoul01897Republic of Korea

Myocardial perfusion imaging(MPI),which uses single-photon emission computed tomography(SPECT),is a well-known estimating tool for medical diagnosis,employing the classification of images to show situations in coronary artery disease(CAD).The automatic classification of SPECT images for different techniques has achieved near-optimal accuracy when using convolutional neural networks(CNNs).This paper uses a SPECT classification framework with three steps:1)Image denoising,2)Attenuation correction,and 3)Image *** denoising is done by a U-Net architecture that ensures effective image *** correction is implemented by a convolution neural network model that can remove the attenuation that affects the feature extraction process of ***,a novel multi-scale diluted convolution(MSDC)network is *** merges the features extracted in different scales and makes the model learn the features more *** scales of filters with size 3×3 are used to extract *** three steps are compared with state-of-the-art *** proposed denoising architecture ensures a high-quality image with the highest peak signal-to-noise ratio(PSNR)value of *** proposed classification method is compared with the five different CNN models,and the proposed method ensures better classification with an accuracy of 96%,precision of 87%,sensitivity of 87%,specificity of 89%,and F1-score of 87%.To demonstrate the importance of preprocessing,the classification model was analyzed without denoising and attenuation correction.

关键词： SPECT-MPI CAD MSDC denoising attenuation correction classification

Metabolic reprogramming: a new option for the treatment of spinal cord injury

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第4期20卷 1042-1057页

作者： Jiangjie Chen Jinyang Chen Chao Yu Kaishun Xia Biao Yang Ronghao Wang Yi Li Kesi Shi Yuang Zhang Haibin Xu Xuesong Zhang Jingkai Wang Qixin Chen Chengzhen Liang Department of Orthopedics The Second Affiliated Hospital of Zhejiang University School of MedicineHangzhouZhejiang ProvinceChina Orthopedics Research institute of Zhejiang University Zhejiang UniversityHangzhouZhejiang ProvinceChina Key Laboratory of Motor system Disease Research and Precision Therapy of Zhejiang Province HangzhouZhejiang ProvinceChina Clinical Research Center of Motor system Disease of Zhejiang Province HangzhouZhejiang ProvinceChina Qiandongnan Prefecture People’s Hospital KailiGuizhou ProvinceChina Department of Orthopedics Fourth Medical CenterChinese PLA General HospitalBeijingChina

Spinal cord injuries impose a notably economic burden on society,mainly because of the severe after-effects they *** the ongoing development of various therapies for spinal cord injuries,their effectiveness remains ***,a deeper understanding of metabolism has opened up a new therapeutic opportunity in the form of metabolic *** this review,we explore the metabolic changes that occur during spinal cord injuries,their consequences,and the therapeutic tools available for metabolic *** spinal cord metabolism is characterized by independent cellular metabolism and intercellular metabolic ***,spinal cord injury results in metabolic disorders that include disturbances in glucose metabolism,lipid metabolism,and mitochondrial *** metabolic disturbances lead to corresponding pathological changes,including the failure of axonal regeneration,the accumulation of scarring,and the activation of *** rescue spinal cord injury at the metabolic level,potential metabolic reprogramming approaches have emerged,including replenishing metabolic substrates,reconstituting metabolic couplings,and targeting mitochondrial therapies to alter cell *** available evidence suggests that metabolic reprogramming holds great promise as a next-generation approach for the treatment of spinal cord *** further advance the metabolic treatment of the spinal cord injury,future efforts should focus on a deeper understanding of neurometabolism,the development of more advanced metabolomics technologies,and the design of highly effective metabolic interventions.

关键词： axons glycolysis metabolic reprogramming metabolism mitochondria neural regeneration neuroprotection oxidative phosphorylation spinal cord injury therapy

High-dose dexamethasone regulates microglial polarization via the GR/JAK1/STAT3 signaling pathway after traumatic brain injury

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第9期20卷 2611-2623页

作者： Mengshi Yang Miao Bai Yuan Zhuang Shenghua Lu Qianqian Ge Hao Li Yu Deng Hongbin Wu Xiaojian Xu Fei Niu Xinlong Dong Bin Zhang Baiyun Liu Beijing Tiantan Hospital Capital Medical UniversityBeijingChina Department of Neurology The First Hospital of Tsinghua UniversityBeijingChina Department of Neurotrauma and Beijing Key Laboratory of Central Nervous system Injury Beijing Neurosurgical InstituteCapital Medical UniversityBeijingChina Department of Critical Care Medicine Beijing Tiantan HospitalCapital Medical UniversityBeijingChina Center for Nerve Injury and Repair Beijing Institute of Brain DisordersChina National Clinical Research Center for Neurological DiseasesBeijingChina

Although microglial polarization and neuroinflammation are crucial cellular responses after traumatic brain injury,the fundamental regulatory and functional mechanisms remain insufficiently *** potent anti-inflammato ry agents,the use of glucoco rticoids in traumatic brain injury is still controversial,and their regulatory effects on microglial polarization are not yet *** the present study,we sought to determine whether exacerbation of traumatic brain injury caused by high-dose dexamethasone is related to its regulatory effects on microglial polarization and its mechanisms of *** vitro cultured BV2 cells and primary microglia and a controlled cortical impact mouse model were used to investigate the effects of dexamethasone on microglial ***,dexamethasone,RU486(a glucocorticoid receptor antagonist),and ruxolitinib(a Janus kinase 1 antagonist)were ***-sequencing data obtained from a C57BL/6 mouse model of traumatic brain injury were used to identify potential targets of *** Morris water maze,quantitative reverse transcription-polymerase chain reaction,western blotting,immunofluorescence and confocal microscopy analysis,and TUNEL,Nissl,and Golgi staining were performed to investigate our ***-throughput sequencing results showed that arginase 1,a marker of M2 microglia,was significantly downregulated in the dexamethasone group compared with the traumatic brain injury group at3 days post-traumatic brain *** dexamethasone inhibited M1 and M2 microglia,with a more pronounced inhibitory effect on M2microglia in vitro and in *** receptor plays an indispensable role in microglial polarization after dexamethasone treatment following traumatic brain ***,glucocorticoid receptor activation increased the number of apoptotic cells and neuronal death,and also decreased the density of dendritic spines.A possible downstream receptor signaling mechanism is th

关键词： apoptosis BV2 microglia dexamethasone glucocorticoid receptor glucocorticoids innate immune system microglial polarization neuroinflammation primary microglia traumatic brain injury

Study on volt-ampere characteristics of solar array arcs in LEO spacecraft

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2019年第2期21卷 39-46页

作者： Liying ZHU Zhigang LIU Xiaofeng ZHANG Chao WANG Xiaofei LI institute of Spacecraft system Engineering CAST

The primary and secondary arcs volt-ampere characteristics of low earth orbit solar arrays are studied in this research. Using three gallium-arsenide solar cell samples, the gap lengths of the solar cell are set to 1, 2, and 3 mm. First, the primary arc voltage characteristics of a solar array are analyzed. It is found that two steps are involved in the primary arc voltages, which are 116 and 22 V according to our experiment and are independent of the electrostatic discharge current and the gap lengths. By comparing with the arc pattern, we determined that current chopping may be the reason for the stepped arc voltage. Then, the characteristics of the secondary arc of the solar array are demonstrated. The study shows that the secondary arc voltage values increase with the gap length. In the case of the same cell with a fixed gap length, the voltage of the secondary arc increases with the string current. Finally, the relationship between the secondary arc voltage and the gap length is obtained which helps the string voltage and the gap length selection for system design.

关键词： primary arc secondary arc solar array

Enhancing recommender systems by incorporating social information

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science C(Computers and Electronics) 2013年第9期14卷 711-721页

作者： Li-wei HUANG Gui-sheng CHEN Yu-chao LIU De-yi LI institute of Command Information system PLA University of Science and Technology institute of Electronic system Engineering

Although recommendation techniques have achieved distinct developments over the decades,the data sparseness problem of the involved user-item matrix still seriously influences the recommendation *** of the existing techniques for recommender systems cannot easily deal with users who have very few *** to combine the increasing amount of different types of social information such as user generated content and social relationships to enhance the prediction precision of the recommender systems remains a huge *** this paper,based on a factor graph model,we formalize the problem in a semi-supervised probabilistic model,which can incorporate different user information,user relationships,and user-item ratings for learning to predict the unknown *** evaluate the method in two different genres of datasets,Douban and *** indicate that our method outperforms several state-of-the-art recommendation ***,a distributed learning algorithm is developed to scale up the approach to real large datasets.

关键词： Recommender system Social information Factor graph model