检索结果-南通市图书馆

Mapping and analyzing the local climate zones in China’s 32 major cities using Landsat imagery based on a novel convolutional neural network

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geo-Spatial Information Science 2021年第4期24卷 528-557页

作者： Xin huang Anling Liu Jiayi Li School of Remote Sensing and Information Engineering Wuhan UniversityWuhanChina State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhanChina

The Local Climate Zone(LCZ)scheme provides researchers with a standard method to monitor the Urban Heat Island(UHI)effect and conduct temperature *** to generate reliable LCZ maps has therefore become a research *** recent years,researchers have attempted to use Landsat imagery to delineate LCZs and generate maps worldwide based on the World Urban Database and Access Portal Tools(WUDAPT).However,the mapping results obtained by the WUDAPT method are not *** this paper,to generate more accurate LCZ maps,we propose a novel Convolutional Neural Network(CNN)model(namely,LCZ-CNN),which is designed to cope with the issues of LCZ classification using Landsat ***,in this study,we applied the LCZ-CNN model to generate LCZ mapping results for China’s 32 major cities distributed in various climatic zones,achieving a significantly better accuracy than the traditional classification strategies and a satisfactory computational *** pro-posed LCZ-CNN model achieved satisfactory classification accuracies in all 32 cities,and the Overall Accuracies(OAs)of more than half of the cities were higher than 80%.We also designed a series of experiments to comprehensively analyze the proposed LCZ-CNN model,with regard to the transferability of the network and the effectiveness of multiseasonal *** was found that the first convolutional stage,corresponding to low-level features,shows better transferability than the second and third convolutional stages,which extract high-level and more image-or task-oriented *** was also confirmed that the multi-seasonal information can improve the accuracy of LCZ *** thermal characteristics of the different LCZ classes were also analyzed based on the mapping results for China’s 32 major cities,and the experimental results confirmed the close relationship between the LCZ classes and the magnitude of the Land Surface Temperature(LST).

关键词： Deep learning convolutional neural network local climate zone scheme land surface temperature

Amplification mechanism of perturbation energy in controlled backward-facing step flow

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2021年第10期42卷 1479-1494页

作者： Yadong huang Desheng ZHANG Fadong GU National Research Center of Pumps Jiangsu UniversityZhenjiang 212013Jiangsu ProvinceChina

A body force resembling the streamwise Lorentz force which decays exponentially in the wall-normalwise direction is applied in the primary and secondary separation bubbles to modify the base flow and thereby adjust the amplification rate of the perturbation *** amplification mechanisms are investigated numerically via analyzing the characteristics of the terms in the Reynolds-Orr equation which describes the growth rate of the perturbation *** results demonstrate that the main convective term always promotes the increase in the growth rate while the viscous terms usually play the reverse *** contours of the product of the wall-normalwise and streamwise perturbation velocities distribute on both sides of the isoline,which represents the zero wall-normalwise gradient of the streamwise velocity in the base flow,due to the Kelvin-Helmholtz(KH)*** the case without control,the isoline downstream the reattachment point of the primary separation bubble is closer to the lower wall,and thus the viscous term near the lower wall might suppress the amplification *** the case in which the body force only acts on the secondary separation bubble,the secondary separation bubble is removed,and the magnitude of the negative wall-normalwise gradient of the base flow streamwise velocity decreases along the streamwise direction,and thus the growth rate of the perturbation energy is smaller than that for the case without *** the case where the body force acts on both the separation bubbles,the secondary separation bubble is removed,the isoline stays in the central part of the channel,and thereby the viscous term has less effects on the amplification rate of which the peak value could be the maximum one for some control number.

关键词： backward-facing step(BFS)flow flow control amplification mechanism perturbation energy

Single-cell analyses identify anaphase-promoting complex subunit 11 as a switch controlling neuronal differentiation of glioblastoma cells

在线全文

学校读者我要写书评

暂无评论

Genes & Diseases 2023年第5期10卷 1802-1805页

作者： Runwei Yang Ziyu Wang Songtao Qi Bowen Ni Jinglin guo Kaishu Li Haimin Song Sidi Xie Yunxiao Zhang Xirang Wang Chunmao He Guanglong huang Yawei Liu Department of Neurosurgery Nanfang HospitalSouthern Medical UniversityGuangzhouGuangdong 510515China Department of Neurosurgery Shunde HospitalSouthern Medical UniversityFoshanGuangdong 528300China Medical Research Center Shunde HospitalSouthern Medical UniversityFoshanGuangdong 528300China Department of Neurosurgery The Sixth Affiliated Hospital of Guangzhou Medical UniversityQingyuan People's HospitalQingyuanGuangdong 511518China School of Chemistry and Chemical Engineering South China University of TechnologyGuangzhouGuangdong 510640China

Glioblastoma(GBM)is the most common and lethal malignancy in the central nervous system.1 One of the major difficulties in treatment is that the initial clinical diagnosis of GBM is already WHO grade IV,without recognizable lower-grade precursor *** number variations(CNVs)were found to appear in malignant cells several years before the initial diagnosis of GBM.2 Less differentiation and more aggressive phenotypes were observed in GBM cells with a higher degree of CNVs.3 Additionally,CNVs provide more accurate stratification of clinical outcomes than does the WHO grade system.4 Therefore,we reasoned that differentially expressed genes(DEGs)among GBM cells with different CNV statuses would be significant for the aggressiveness of *** we leveraged the single-cell RNA-sequencing(scRNA-seq)to construct the CNV profile of GBM at single-cell resolution,divided GBM cells into different clusters according to their CNV statuses,and investigated the molecular functions of DEGs among GBM *** a series of experiments,we identified anaphase-promoting complex subunit 11(ANAPC11)as a switch controlling the neuronal differentiation of GBM cells,providing a novel alternative for the development of differentiation-inducing therapy to overcome GBM.

关键词： diagnosis controlling system.

GridNet:efficiently learning deep hierarchical representation for 3D point cloud understanding

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2022年第1期16卷 1-9页

作者： Huiqun WANG Di huang Yunhong WANG Laboratory of Intelligent Recognition and Image Processing School of Computer Science and EngineeringBeihang UniversityBeijing100191China

In this paper,we propose a novel and effective approach,namely GridNet,to hierarchically learn deep representation of 3D point *** incorporates the ability of regular holistic description and fast data processing in a single framework,which is able to abstract powerful features progressively in an efficient ***,to capture more accurate internal geometry attributes,anchors are inferred within local neighborhoods,in contrast to the fixed or the sampled ones used in existing methods,and the learned features are thus more representative and discriminative to local point *** delivers very competitive results compared with the state of the art methods in both the object classification and segmentation tasks.

关键词： 3D point clouds deep representations

海藻酸钠离子凝胶法制备直通孔氧化铝多孔陶瓷

在线全文

学校读者我要写书评

暂无评论

无机材料学报 2015年第8期30卷 877-881页

作者：孙阳薛伟江孙加林周国治黄勇北京科技大学材料科学与工程学院北京100083 清华大学新型陶瓷与精细工艺国家重点实验室材料科学与工程学院北京100084

利用海藻酸钠的离子凝胶过程,采用溶剂置换结合冷冻干燥的工艺,成功制备了具有高度有序六方排列的直通孔多孔氧化铝陶瓷,整个工艺过程及所使用的原料都是环境友好的。研究结果表明,1500℃烧结2 h样品的孔径尺寸在200μm左右,且与固相含... 详细信息

利用海藻酸钠的离子凝胶过程,采用溶剂置换结合冷冻干燥的工艺,成功制备了具有高度有序六方排列的直通孔多孔氧化铝陶瓷,整个工艺过程及所使用的原料都是环境友好的。研究结果表明,1500℃烧结2 h样品的孔径尺寸在200μm左右,且与固相含量的关系不大,而孔壁上存在0.3μm^0.5μm的小孔。通过控制浆料中氧化铝的固相含量可以对材料的性能进行有效地调控,研究表明,随着固相含量从5wt%提高到15wt%,材料的密度从0.87 g/cm3提高到1.16 g/cm3,渗透率从2.57×10-11 m2下降到2.16×10-11 m2,而抗压强度从(18.9±3.2)MPa提高到(44.2±5.4)MPa,平行孔道方向的热导率从2.1 W/(m·K)提高到3.1 W/(m·K),而垂直孔道方向的热导率从1.3 W/(m·K)提高到1.7 W/(m·K),并且平行孔道方向热导率的增加幅度要明显大于垂直孔道方向。

关键词：直通孔氧化铝多孔陶瓷渗透率热导率离子凝胶

An Online Compensation Method of DC Drift for Three-Phase Current Reconstruction with DC-Link Resistance

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2020年第5期29卷 982-990页

作者： huang Lili ZHENG Lianqing LI Pengwei Department of Electric Machine and Electric Apparatus School of Electrical Engineering Chongqing University State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University

In a three-phase power convertor system,phase current reconstruction technique using a DC-link resistance can reduce the cost and weight of the diving system. The three-phase current without DC offset in normal condition is introduced in this paper *** on this premise, the DC-link current offset is considered and the logical relationship between threephase voltage, three-phase current, and DC offset are analyzed and depicted. The DC offset introduced during the sampling processes a distortion into phase current,which is composed of fundamental and harmonic frequency based on FFT analysis. The fundamental component of the distortion shares the same phase angle with counterpart voltage, which distorts power factor and amplitude of three-phase currents. The harmonic components of the distortion can be transformed into 6th harmonic components in synchronous dq axes and undermine the performance of the controlling system. After that, a practical method is proposed to solve this problem, namely sampling the DC offset signal during the period of the zero voltage vectors. An analogy sample circuit is designed and tested. This method can avoid the DC offset from the source. Finally, its effectiveness is verified via simulation and experiment.

关键词： Phase current reconstruction DC offset FFT analysis Current deviation

Conditional Coverage Estimation for High-Quality Prediction Intervals

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Science and Systems Engineering 2023年第3期32卷 289-319页

作者： Ziyi huang Henry Lam Haofeng Zhang School of Engineering and Applied Science Columbia UniversityNew YorkNY 10027USA

Deep learning has been recently studied to generate high-quality prediction intervals(PIs)for uncertainty quantification in regression tasks,including recent applications in simulation *** high-quality criterion requires PIs to be as narrow as possible,whilst maintaining a pre-specified level of data(marginal)***,most existing works for high-quality PIs lack accurate information on conditional coverage,which may cause unreliable predictions if it is significantly smaller than the marginal *** address this problem,we propose an end-to-end framework which could output high-quality PIs and simultaneously provide their conditional coverage *** doing so,we design a new loss function that is both easy-to-implement and theoretically justified via an exponential concentration *** evaluation on real-world benchmark datasets and synthetic examples shows that our approach not only achieves competitive results on high-quality PIs in terms of average PI width,but also accurately estimates conditional coverage information that is useful in assessing model uncertainty.

关键词： Uncertainty quantification prediction intervals conditional coverage neural networks calibrationerror

Additive manufacturing of high-strength Inconel 718 alloy through the addition of Ti_(2) AlC MAX particles

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2023年第27期158卷 180-193页

作者： Yu Kong Kaiyuan Peng Haihong huang School of Mechanical Engineering Hefei University of TechnologyHefei 230009China Key Laboratory of Green Design and Manufacturing of Mechanical Industry Hefei University of TechnologyHefei 230009China

Decreasing the content of detrimental Laves phase in additively manufactured Inconel 718 alloy is highly *** the present study,we introduce a novel approach to effectively suppress the precipitation of Laves *** ex-situ incorporation of Ti_(2) AlC MAX particles,Ti_(2) AlC/Inconel 718 composites with Ti_(2) AlC volume fractions of 5%and 10%are successfully fabricated using the directed energy deposition(DED)*** comparison to the Inconel 718 alloy,the 10 vol.%Ti_(2) AlC/Inconel 718 composite exhibits 70.9%higher yield strength,39.1%higher ultimate tensile strength,and 61.4%higher hardness.A detailed microstructure examination confirms that the detrimental Laves phase,which is abundantly present in the inter-dendritic region,is replaced by in-situ formed(Nb,Ti)(C,N)andγ’particles with average diam-eters of 1.12μm and 10 nm,*** non-equilibrium solidification process simulation,the suppression of Laves phase,in-situ formation of multi-scale precipitates,and the microstructural evolu-tion due to Ti_(2) AlC addition are illustrated at the mechanistic ***,a theoretical model of Ti_(2) AlC/Inconel 718 composite is developed to reveal its underlying strengthening *** is indi-cated that Ti_(2) AlC/Inconel 718 composites possess the capability to be a next-generation high-end nickel-based alloy.

关键词： Additive manufacturing Inconel 718 Max phase Microstructure Mechanical properties

Propagation of Smooth Pulses in Anomalously Dispersive Media

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2005年第4X期44卷 715-718页

作者： huang Chao-Guang Institute of High Energy Physics the Chinese Academy of Sciences P.O. Box 918-4 Beijing 100049 China

In the present letters we study the propagation of smooth pulses in anomalously dispersive media. We prove that non-analytical but smooth points in a pulse still propagate with the vacuum speed of light, c. It gives an upper limit for signal velocity as well as the non-continuous points of the envelop of a pulse or its derivatives of arbitrary order do.

关键词： anomalous dispersion smooth pulse signal velocity