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Analysis of large-scale UAV images using a multi-scale hierarchical representation

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Geo-Spatial Information Science 2018年第1期21卷 33-44页

作者： huai yu Jinwang Wang yu Bai Wen Yang Gui-Song Xia School of Electronic Information Wuhan UniversityWuhanChina Collaborative Innovation Center of Geospatial Technology Wuhan UniversityWuhanChina State Key Laboratory for Information Engineering in Surveying Mapping and Remote Sensing(LIESMARS)Wuhan UniversityWuhanChina

Unmanned aerial vehicle(UAV)-based imaging systems have many superiorities compared with other platforms,such as high flexibility and low cost in collecting images,providing wide application ***,the acquisition of the UAV-based image commonly results in very high resolution and very large-scale images,which poses great challenges for subsequent ***,an efficient representation of large-scale UAV images is necessary for the extraction of the required information in a reasonable *** this work,we proposed a multi-scale hierarchical representation,*** partition tree,for analyzing large-scale UAV *** precisely,we first obtained an initial partition of images by an oversegmentation algorithm,*** simple linear iterative ***,we merged the similar superpixels to build an object-based hierarchical structure by fully considering the spectral and spatial information of the superpixels and their topological ***,objects of interest and optimal segmentation were obtained using object-based analysis methods with the hierarchical *** results on processing the post-seismic UAV images of the 2013 Ya’an earthquake and the mosaic of images in the South-west of Munich demonstrate the effectiveness and efficiency of our proposed method.

关键词： Unmanned aerial vehicle(UAV)image binary partition tree(BPT) object-based image analysis(OBIA) hierarchical segmentation object detection

Application of pole-zero cancellation circuit in nuclear signal filtering and shaping algorithm

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Nuclear Science and Techniques 2021年第8期32卷 85-94页

作者： huai-Ping Wang jian-Bin Zhou Xiao-Ping Ouyang Xian-Guo Tuo Xu Hong Yi Liu Jie yu You-Xian Jin College of Nuclear Technology and Automation Engineering Chengdu University of TechnologyNo.1 East 3 RoadErxian BridgeChenghua DistrictChengdu 610059China Northwestern Institute of Nuclear Technology Xi’an 710024China Engineering Research Center of Nuclear Technology Application(East China University of Technology) Ministry of EducationNanchang 330013China

In radiation measurement and digital nuclear spectrum systems,traditional nuclear signal processing circuits in nuclear electronics have been gradually replaced by digital algorithm modules with the application of highperformance programmable hardware logic devices(such as FPGA or DSP).Referring to the digital realization method of inverse RC integral circuit systems,the function of the pole-zero cancellation(PZC)circuit was analyzed,a new modified cascade equivalent model of PZC was established,and the time-domain digital PZC(DPZC)recursive algorithm was derived in detail in this *** parameters kIand k_(D)are included in the new algorithm,where kIshould match the exponential decay time constant of the input signal to realize the pole-zero compensation,while the decay time constant of the output signal can be changed with the adjustable parameter k_(D)(which is larger than the decay time constant of the input signal).Based on the new DPZC algorithm module,two trapezoidal(triangular)shaping filters were designed and *** amplitude–frequency characteristics of the output signal of the proposed trapezoidal shaping algorithm and the convolution trapezoidal shaping algorithm were compared,with fixed peaking *** results show that the trapezoidal shaping algorithm based on DPZC can better suppress high-frequency ***,based on the Na I(Tl)scintillator(u75 mm×75 mm)detector and^(137)Cs source,the effect of the k_(D)value on the energy resolution of the DPZC trapezoidal(triangular)shaping algorithm was *** experimental results show that,with an increase in k_(D),the energy resolution of the system improved and reached the maximum when k_(D)was greater than 10,and the optimal energy resolution of the system was 7.72%.

关键词： Pole-zero cancellation C–R inverse system Trapezoidal/triangular shaping Amplitude–frequency characteristics Energy resolution

Microstructure and mechanical properties of high-strength high-pressure die-cast Mg–4Al–3La–1Ca–0.3Mn alloy

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Rare Metals 2021年第10期40卷 2956-2963页

作者： Peng-Fei Qin Qiang Yang yu-Ying He Jing-huai Zhang Jin-Shu Xie Xi-Ru Hua Kai Guan jian Meng Key Laboratory of Superlight Materials and Surface Technology Ministry of EducationHarbin Engineering UniversityHarbin 150001China State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Department of Materials Science and Engineering University of TokyoTokyo 113-8654Japan

A new high-pressure die-cast(HPDC) Mg–4 Al–3 La–1 Ca–0.3 Mn(ALaX431) alloy with high strength has successfully been fabricated. This HPDC alloy in peakaged state exhibits tensile yield strength(TYS) of 220 MPa at room temperature and TYS of 145 MPa at 250 ℃,higher than the corresponding strength of HPDC Mg alloys reported so far. These high strengths are mainly due to the formation of fine grained structure, semi-continuous reticular structure consisting of stable Al_(3)La and(Mg,Al)2 Ca particles along grain boundaries and numerous nanoscale Al_(2)Ca precipitates within grains. Due to its higher strength than existing HPDC Mg alloys, the new developed alloy has great application potential.

关键词： Magnesium alloys High-pressure die-cast Mechanical property Intermetallic phase

Electrolytes additives for Zn metal anodes:regulation mechanism and current perspectives

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Rare Metals 2024年第9期43卷 4162-4197页

作者： yu-Zhe Zhang huai-Sheng Ao Qi Dong Shao-Jie Zhang Zhi-Guo Hou Na-Na Wang Xue-Song Xie jian Rong Zhong-yu Li School of Environmental Science and Engineering Changzhou UniversityChangzhou 213164China School of Petrochemical Engineering Changzhou UniversityChangzhou 213164China Hefei National Laboratory for Physical Science at Microscale School of Chemistry and Materials ScienceUniversity of Science and Technology of ChinaHefei 230026China Institute for Superconducting and Electronic Materials Australian Institute for Innovative MaterialsInnovation CampusUniversity of WollongongNorth WollongongNSW 2500Australia Department of Chemical and Materials Engineering University of AlbertaEdmonton AB T6G 1H9Canada

With distinct advantages such as high gravimetric and volumetric capacity(5855 mAh·cm^(-3)and 820mAh·g^(-1)),low redox potential(-0.762 V *** hydrogen electrode(SHE)),high abundance,low toxicity and intrinsic safety of Zn metal anode,Zn-ion batteries have become a potential alternative to Li-ion ***,several challenges still need to be addressed prior to the practical applications of Zn-ion batteries,such as dendrite growth during Zn plating/stripping and interfacial side reactions on the Zn *** issues can be addressed by introducing additives to regulate the components and structures of the *** this review,we systematically discussed the core issues of metallic Zn anodes and comprehensively summarized a novel perspective of the regulation mechanism of inhibiting dendrite growth or interfacial side reactions in Zn anodes by introducing additives into aqueous ***,some discussions and prospects for aqueous Zn ion batteries(AZIBs)are presented for future research.

关键词： Electrolyte additives Zn metal anode Regulation mechanism Current perspectives AZIBs

Thermomechanical Fatigue Behavior of Powder Metallurgical Nickel Based Superalloy FGH96

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Journal of Iron and Steel Research International 2010年第6期17卷 74-79页

作者： GU yu-li TAO Chun-hu HE yu-huai Beijing Institute of Aeronautical Materials Beijing 100095 China

The fracture behavior of the thermomechanical fatigue （TMF） of the powder metallurgical nickel based superalloy FGH96 was investigated under in-phase （IP） and out-of-phase （OP） loadings in the temperature range from 550 ℃ to 720 ℃ and the mechanical strain amplitude range from 0.3% to 0.8%. The results show that the FGH96 TMF fracture character is intergranular for the IP samples and transgranular cleavage-like for the OP samples, at the same strain amplitude, the fatigue life is shorter for the IP than that for the OP samples that is related to crack propagation along grain boundary on the IP samples, the γ′ size is larger in the IP than that in the OP sample, which is related to the bulk diffusion processes accelerated by the tensile strain during the high temperature portion of the IP cycle. Dislocation pairs and stacking faults are main microstructures induced by IP TMF, and they are hindered by the grain boundary, which likely resulted in the crack propagation along the grain boundary in the IP samples.

关键词： nickel based superalloy powder metallurgy thermomechanical fatigue γ′ size dislocation

Estimation of the Asian telecommunication technical efficiencies with panel data

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The Journal of China Universities of Posts and Telecommunications 2007年第1期14卷 111-114页

作者： YANG yu-yong JIA huai-jing School of Economics and Management Beijing University of Posts and Telecommunications Beijing 100876 China

This article used panel data and the Stochastic frontier analysis （SFA） model to analyze and compare the technical efficiencies of the telecommunication industry in 28 Asian countries from 1994 to 2003. In conclusion, the technical efficiencies of the Asian countries were found to steadily increase in the past decade. The high-income countries have the highest technical efficiency; however, income is not the only factor that affects the technical efficiency.

关键词： panel data SFA technical efficiency Asian telecommunication sectors

Characterizations and Extensions of Lipschitz-α Operators

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Acta Mathematica Sinica,English Series 2006年第3期22卷 671-678页

作者： huai Xin CAO jian Hua ZHANG Zong Ben XU College of Mathematics and Information Science Shaanxi Normal University Faculty of Science Xi'an Jiaotong University

In this work, we prove that a map F from a compact metric space K into a Banach space X over F is a Lipschitz-α operator if and only if for each σ in X^＊ the map σoF is a Lipschitz-α function on K. In the case that K = [a, b], we show that a map f from [a, b] into X is a Lipschitz-1 operator if and only if it is absolutely continuous and the map σ→ （σ o f）＇ is a bounded linear operator from X^＊ into L^∞（[a, b]）. When K is a compact subset of a finite interval （a, b） and 0 〈 α ≤ 1, we show that every Lipschitz-α operator f from K into X can be extended as a Lipschitz-α operator F from [a, b] into X with Lα（f） ≤ Lα（F） ≤ 3^1-α Lα（f）. A similar extension theorem for a little Lipschitz-α operator is also obtained.

关键词： Characterization Extension Lipschitz-α operator

Magnetization of Coupled Ultrathin Ferromagnetic Films

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Communications in Theoretical Physics 2002年第7期38卷 107-112页

作者： WANG huai-yu ZHOU yun-Song WANG Chong-yu Department of Physics Tsinghua University Beijing 100084 China Department of Physics Capital Normal University Beijing 100037 China Department of Physics Tsinghua University Beijing 100084 China

The magnetization of coupled ferromagnetic films is calculated by Green's function method. The coupling can either be ferromagnetic or antiferromagnetic. For the latter case, a concept of pseudo-spin is suggested to make calculation possible. A pseudo-spin is actually an anti-spin with its properties being analogue to other known anti particles such as a hole. The decreasing of Curie point as the coupling strength decays is computed. It is noted that with the same strength, antiferromagnetic coupling has higher Curie point than ferromagnetic coupling.

关键词： magnetization, pseudo-spin, coupled ferromagnetic films

Learning Rates for Least Square Regressions with Coefficient Regularization

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Acta Mathematica Sinica,English Series 2012年第11期28卷 2205-2212页

作者： Bao huai SHENG Pei Xin YE jian Li WANG Department of Mathematics Shaoxing College of Arts and Sciences School of Mathematical Sciences and LPMC Nankai University

We analyze the learning rates for the least square regression with data dependent hy- pothesis spaces and coefficient regularization algorithms based on general kernels. Under a very mild regularity condition on the regression function, we obtain a bound for the approximation error by esti- mating the corresponding K：-functional. Combining this estimate with the previous result of the sample error, we derive a dimensional free learning rate by the proper choice of the regularization parameter.

关键词： Least square regressions coefficient regularization general kernel M-functional learningrates