检索结果-南通市图书馆

Non-negative matrix factorization based unmixing for principal component transformed hyperspectral data

在线全文

学校读者我要写书评

暂无评论

Frontiers of Information Technology & Electronic Engineering 2016年第5期17卷 403-412页

作者： Xiu-rui GENG lu-yan JI kang SUN Key Laboratory of Technology in Geo-spatial Information Processing and Application System Institute of Electronics Chinese Academy of Sciences Beijing 100190 China MOE Key Laboratory for Earth System Modeling Center for Earth System Science Tsinghua University Beijing 100084 China The 54th Research Institute of China Electronics Technology Group Corporation Shijiazhuang 050000 China

Non-negative matrix factorization(NMF) has been widely used in mixture analysis for hyperspectral remote sensing. When used for spectral unmixing analysis, however, it has two main shortcomings:(1) since the dimensionality of hyperspectral data is usually very large, NMF tends to suffer from large computational complexity for the popular multiplicative iteration rule;(2) NMF is sensitive to noise(outliers), and thus the corrupted data will make the results of NMF meaningless. Although principal component analysis(PCA) can be used to mitigate these two problems, the transformed data will contain negative numbers, hindering the direct use of the multiplicative iteration rule of NMF. In this paper, we analyze the impact of PCA on NMF, and find that multiplicative NMF can also be applicable to data after principal component transformation. Based on this conclusion, we present a method to perform NMF in the principal component space, named ‘principal component NMF'(PCNMF). Experimental results show that PCNMF is both accurate and time-saving.

关键词： Non-negative matrix factorization(NMF) Principal component analysis(PCA) Endmember Hyperspectral

Location and allocation problem for spare parts depots on integrated logistics support

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2019年第6期30卷 1252-1259页

作者： WEN Meilin lu Bohan LI Shuyu kang Rui School of Reliability and Systems Engineering Beihang UniversityBeijing 100191China Science and Technology on Reliability and Environmental Engineering Laboratory Beijing 100191China

In equipment integrated logistics support(ILS), the supply capability of spare parts is a significant factor. There are lots of depots in the traditional support system, which makes too many redundant spare parts and causes high cost of support. Meanwhile,the inconsistency among depots makes it difficult to manage spare parts. With the development of information technology and transportation, the supply network has become more efficient. In order to further improve the efficiency of supply-support work and the availability of the equipment system, building a system of one centralized depot with multiple depots becomes an appropriate *** this case, location selection of the depots including centralized depots and multiple depots becomes a top priority in the support system. This paper will focus on the location selection problem of centralized depots considering ILS factors. Unlike the common location selection problem, depots in ILS require a higher service level. Therefore, it becomes desperately necessary to take the high requirement of the mission into account while determining location of depots. Based on this, we raise an optimal depot location model. First, the expected transportation cost is ***, factors in ILS such as response time, availability and fill rate are analyzed for evaluating positions of open depots. Then, an optimization model of depot location is developed with the minimum expected cost of transportation as objective and ILS factors as constraints. Finally, a numerical case is studied to prove the validity of the model by using the genetic algorithm. Results show that depot location obtained by this model can guarantee the effectiveness and capability of ILS well.

关键词： location problem spare parts depot integrated logis tics support genetic algorithm.

A Novel Face Recognition Algorithm for Distinguishing Faces with Various Angles

在线全文

学校读者我要写书评

暂无评论

International Journal of Automation and computing 2008年第2期5卷 193-197页

作者： yong-Zhong lu School of Software Engineering Huazhong University of Science and Technology Wuhan 430074 PRC

In order to distinguish faces of various angles during face recognition, an algorithm of the combination of approximate dynamic programming （ADP） called action dependent heuristic dynamic programming （ADHDP） and particle swarm optimization （PSO） is presented. ADP is used for dynamically changing the values of the PSO parameters. During the process of face recognition, the discrete cosine transformation （DCT） is first introduced to reduce negative effects. Then, Karhunen-Loeve （K-L） transformation can be used to compress images and decrease data dimensions. According to principal component analysis （PCA）, the main parts of vectors are extracted for data representation. Finally, radial basis function （RBF） neural network is trained to recognize various faces. The training of RBF neural network is exploited by ADP-PSO. In terms of ORL Face Database, the experimental result gives a clear view of its accurate efficiency.

关键词： Face recognition approximate dynamic programming (ADP) particle swarm optimization (PSO)

Spinodal dynamics of metastable glass transition domains in amorphous polymer towards thermomechanically tailorable shape memory effect

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2023年第8期66卷 2432-2440页

作者： LIU JingYun lu HaiBao FU yong-Qing Science and Technology on Advanced Composites in Special Environments Laboratory Harbin Institute of TechnologyHarbin 150080China Faculty of Engineering and Environment Northumbria UniversityNewcastle upon TyneNE18STUK

Glass transition plays a critical role to determine the dynamic behaviors of amorphous shape memory polymers(SMPs).However,the fundamental relationships between shape memory effect(SME)and dynamic glass transition have not been well understood,even though this topic has been studied for *** this study,we apply a mean-square displacement function of Adam-Gibbs(AG)domain size model to explore metastable glass transition between normal glass state and rubbery state of amorphous SMPs,based on both mode-coupling theory and mean-field model.A statistic viscosity equation is formulated to study the dynamic glass transition of metastable AG domains in an amorphous SMP.A dynamically spinodal model is also developed to connect dynamic glass transitions to thermomechanical processes,based on statistic viscosity equation and phase transition ***,using the spinodal models,multiple shape memory behaviors have been predicted for amorphous SMPs with dual-,triple-and quadruple-SMEs,resulted from their different routes of themomechanical ***,the proposed models are verified using the experimental data reported in literature.

关键词： shape memory polymer glass transition dynamics metastable

同方期刊数据库

SURFACE FUNCTIONALIZATION OF POLYSTYRENE TO BIND WITH FMRF PEPTIDES FOR NOVEL BIOCOMPATIBILITY

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2010年第6期28卷 895-902页

作者： yong Chen Hong-sheng lu Peng Wang Department of Applied Chemistry School of Chemical & Environmental Engineering Shandong University of Science and Technology Qingdao 266510 China Department of Environmental Science and Technology School of Chemical & Environmental Engineering Shandong University of Science and Technology Qingdao 266510 China

A generic method was described to change surface biocompatibihty by introducing reactive functional groups onto surfaces of polymeric substrates and covalently binding them with biomolecules.A block copolymer with protected carboxylic acid functionality,poly（styrene-b-tert-butyl acrylate）（PS-PtBA）,was spin coated from solutions in toluene on a bioinert polystyrene（PS） substrate to form a bilayer structure：a surface layer of the poly（tert-butyl acrylate）（PtBA） blocks that order at the air-polymer interface and a bottom layer of the PS blocks that entangle with the PS *** thickness of the PtBA layer and the area density of tert-butyl ester groups of PtBA increased linearly with the concentration of the spin coating solution until a 2 nm saturated monolayer coverage of PtBA was achieved at the concentration of 0.4%W/*** protected carboxylic acid groups were generated by exposing the tert-butyl ester groups of PtBA to trifluoroacetic acid （TFA） for bioconjugation with FMRF peptides via amide *** yield of the bioconjugation reaction for the saturated surface was calculated to be 37.1%based on X-ray photoelectron spectroscopy（XPS） *** success of each functionalization step was demonstrated and characterized by XPS and contact angle *** polymer functionalization/modification concept can be virtually applied to any polymeric substrate by choosing appropriate functional block copolymers and biomolecules to attain novel biocompatibility.

关键词： Surface functionalization Biocompatibility Bioconjugation reaction

Effects of pre-aging on microstructure evolution and deformation mechanisms of hot extruded Mg–6Zn–1Gd–1Er Mg alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2023年第1期11卷 317-328页

作者： Wei kang Liwei lu Longbiao Feng Fengchi lu Chunlei Gan Xiaohui Li School of Materials Science and Engineering Hunan University of Science and TechnologyXiangtan 411201PR China Guangdong Institute of Materials and Processing Guangdong Academy of SciencesGuangzhou 510650PR China School of Mechatronics Engineering and Automation Foshan UniversityFoshan 528000PR China Guangdong Tsing Impulse Science and Technology Co.Ltd. Foshan 528226PR China

The influence of pre-aging treatment on the microstructure,texture and mechanical properties of the Mg–6Zn–1Gd–1Er(wt.%)alloy was *** microstructure analysis shows that the presence of pre-aging is beneficial to{1012}twin nucleation at the early stage of extrusion and inhibits the growth of twins and promotes the formation of[1010]-fiber texture components,thus accelerating the complex process of *** the middle stage of extrusion,the extruded samples under the condition of solid solution were subjected to dynamic precipitation during severe shear *** precipitation of the second phase particles followed the particle stimulating nucleation(PSN)mechanism,which increased the volume fraction of DRX grains during *** the extruded samples under the peak-aged condition,the particles appear dissolved during the severe shear deformation strain,which slows down the DRX *** the later stage of extrusion,the small rod-shaped particles followed the PSN mechanism,and finally formed the strong fiber *** extruded alloy exhibits the strongest mechanical properties under the peak-aged state,with ultimate tensile strength(UTS)of 346 MPa,tensile yield strength(TYS)of 217 MPa,and elongation to failure(EL)of 13.6%.The improvement of mechanical properties is mainly attributed to the existence of strong fiber texture,small rod-shaped and block-shaped phases.

关键词： Mg alloys Pre-aging Extrusion Texture Dynamic recrystallization

Rapid and mass manufacturing of soft hydrogel microstructures for cell patterns assisted by 3D printing

在线全文

学校读者我要写书评

暂无评论

Bio-Design and Manufacturing 2022年第4期5卷 641-659页

作者： Chaofan He Xuechun Chen Yuan Sun Mingjun Xie kang Yu Jing He Jinwei lu Qing Gao Jing Nie Yi Wang yong He State Key Laboratory of Fluid Power and Mechatronic Systems School of Mechanical EngineeringZhejiang UniversityHangzhou 310027China Pharmaceutical Informatics Institute College of Pharmaceutical SciencesZhejiang UniversityHangzhou 310058China Department of Orthopedic Surgery The Second Affiliated HospitalSchool of MedicineZhejiang UniversityHangzhou 310009China Key Laboratory of Materials Processing and Mold Zhengzhou UniversityZhengzhou 450002China Key Laboratory of 3D Printing Process and Equipment of Zhejiang Province College of Mechanical EngineeringZhejiang UniversityHangzhou 310027China Cancer Center Zhejiang UniversityHangzhou 310058China State Key Laboratory of Component-Based Chinese Medicine Tianjin University of Traditional Chinese MedicineTianjin 300072China

Micro-/nano-patterns on hydrogels are widely used in cell ***,manufacturing molds with traditional lithography is time-consuming and *** addition,the excessive demolding force can easily damage patterns since biocompatible hydrogels are ultra-soft or ***,we presented a novel method for rapid and mass fabrication of cell ***-precision three-dimensional(3D)printing was used to manufacture a mold with a resolution of 2µm,and the gelatin-based hydrogel was cured by thermal–photo-crosslinking so that the low-concentration and low-substitutionrate hydrogel could be demolded *** found that pre-cooling before illumination made gelatin-based hydrogels resilient due to the partial regain of triple-helix *** this method,arbitrarily customized hydrogel patterns with a feature size of 6–80µm can be fabricated stably and at low *** cardiomyocytes were seeded on ultra-soft hydrogels with parallel groove structures,a consistent and spontaneous beating with 216 beats per minute(BPM)could be observed,approaching the natural beating rate of rat hearts(300 BPM).Overall,this work provides a general scheme for manufacturing cell patterns which has great potential for cell ethology and tissue repair.

关键词： 3D printing Gelatin-based hydrogel Cell pattern Cardiomyocytes beating

An approach of motion compensation and ISAR imaging for micro-motion targets

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2021年第1期32卷 68-80页

作者： WANG yong ZHOU Xingyu lu Xiaofei LI Yajun School of Electronics and Information Engineering Harbin Institute of TechnologyHarbin 150001China Jiuquan Satellite Launch Center Jiuquan 732750China Shanghai Radio Equipment Research Institute Shanghai 201109China

Inverse synthetic aperture radar(ISAR)imaging of the target with the non-rigid body is very important in the field of radar signal *** this paper,a motion compensation method combined with the preprocessing and global technique is proposed to reduce the influence of micro-motion components in the fast time domain,and the micro-Doppler(m-D)signal in the slow time domain is separated by the improved complex-valued empirical-mode decomposition(CEMD)algorithm,which makes the m-D signal more effectively distinguishable from the signal for the main body by translating the target to the Doppler ***,a better focused ISAR image of the target with the non-rigid body can be obtained *** of the simulated and raw data demonstrate the effectiveness of the algorithm.

关键词： inverse synthetic aperture radar(ISAR) micro-Doppler(m-D) motion compensation complex-valued empiricalmode decomposition(CEMD)

A coordinated planning strategy of energy storage allocation and line upgrading to increase photovoltaic consumption with lowest planning cost

在线全文

学校读者我要写书评

暂无评论

Science China Technological Sciences 2025年

作者： Bo ZHANG Yuqi JI lu ZHANG Wei TANG Xiaohui ZHANG Liang WANG Haoran DING Hanchen MAO College of Information and Electrical Engineering China Agricultural University State Grid Heilongjiang Electric Power Research Institute State Grid Heilongjiang Electric Power Company Limited School of Electrical and Information Engineering Zhengzhou University of Light Industry

Random integration of massive distributed photovoltaic (PV) generation poses serious challenges to distribution networks. Voltage violations, line overloads, increased peak–valley differences, and power-flow reversals can occur at different locations, times, and severities. Traditional planning methods such as energy storage (ES) allocation and upgrading of lines may result in poor economics and low equipment utilization. This study proposes a distribution-network planning strategy that coordinates three planning mechanisms:ES allocation to substations and to feeders, and line upgrading. The proposed strategy achieved the lowest annual cost, considering the distribution network problems at different locations, times, and severities. A net load curve description method was first proposed considering economic planning and the uncertain distribution of loads and PVs. Second, a multistage optimization model for ES allocation and line upgrading was established based on the net load curves. Finally, an improved IEEE33 node system was used in the case study. The planning results show that the proposed coordinated planning strategy can address the problems caused by the random integration of massive distributed PVs, improve equipment utilization, and obtain the lowest total annual planning cost.

关键词：