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Emergence of higher-level neuron properties using a hierarchical statistical distribution model

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Science China(Technological Sciences) 2019年第4期62卷 628-634页

作者： XIAN Ning DENG Yi min duan HaiBin School of Automation Science and Electrical Engineering Beihang University

Essential to visual tasks such as object recognition is the formation of effective representations that generalize from specific instances of visual input. Neurons in primary visual cortex are typically hypothesized to efficiently encode image structures such as edge and textures from natural scenes. Here this paper proposed a novel hierarchical statistical distribution model to generalize higher-level neuron properties and encode distributed regularities that characterize local image regions. Two layers of our hierarchical model are presented to extract spiking activities of excitatory neurons decorrelated by inhibitory neurons and to construct the statistical patterns of input data, respectively. Trained on whitened natural images, parameters including neural connecting weights and distribution coding weights are estimated by their corresponding learning rules. To prove the feasibility and effectiveness of our model, several experiments on natural images are conducted. Adapting our model to natural scenes yields a distributed representation for higher-order statistical regularities. Comparison results provide insight into higher-level neurons which encode more abstract and invariant properties.

关键词： statistical distribution spiking activity object classification localization

On Blocks in Restricted Representations of Lie Superalgebras of Cartan Type

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Acta Mathematica Sinica,English Series 2020年第9期36卷 1061-1075页

作者： Fei Fei duan Bin shu Yu Feng YAO School of Mathematical Sciences Hebei Normal UniversityShijiazhuang 050024P.R.China School of Mathematical Sciences East China Normal UniversityShanghai 200241P.R.China Department of Mathematics Shanghai Maritime UniversityShanghai 201306P.R.China

Let g be a restricted Lie superalgebra of Cartan type W(n),S(n)or H(n)over an alge-braically closed field k of prime characteristic p>3,in the sense of modular version of Kac's definition in *** this note,we show that the restricted representation category over g has only one block(reckoning parities in).This phenomenon is very diff erent from the case of characteristic zero.

关键词： Lie superalgebra of Cartan type restricted representation block

Resist nanokirigami for multipurpose patterning

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National Science Review 2022年第11期9卷 68-78页

作者： Qing Liu Yiqin Chen Zhanyong Feng Zhiwen shu Huigao duan National Engineering Research Center for High Efficiency Grinding State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan University

Resist-based patterning solutions play essential roles in modern micro-and nanoscale science and technology. The commonly used 'resist' patterning strategy depends on selective-area scission or cross-linking of resist molecules under the action of an energy beam. In this work, we propose and demonstrate a different resist-patterning strategy, termed 'resist nanokirigami', in which the resist structures are defined by their outlines and revealed by selective mechanical peeling of the unwanted resist *** conventional resist-based patterning processes, the final resist-nanokirigami structures do not undergo exposure and the exposure area is dramatically reduced. With these two advantages, a variety of functional structures that are difficult or impossible to fabricate by conventional processes, such as inverse nanostructures and their oligomers, multi-scale electrodes and freestanding plasmonic nanogaps, can be easily achieved with much higher efficiency. Thus, with its unique and complementary capabilities, the resist-nanokirigami process provides a new patterning solution that expands the family of lithography techniques and will play a significant role in fabricating multi-scale functional structures.

关键词： nanokirigami multi-scale patterning multipurpose patterning electron-beam lithography inverse structure

Study of parametric roll in oblique waves using a three-dimensional hybrid panel method

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Journal of Hydrodynamics 2020年第1期32卷 126-138页

作者： min Gu shu-xia Bu Jiang Lu Jiangsu Key Laboralory of Green Ship Technology China Ship Scientific Research CenterWiuxi 214082.China

A reliable numerical tool for the prediction of the parametric roll is important in the development of the second generation intact stability *** main difficulty of the prediction of the parametric roll comes from the significant coupling of the roll with other motions,especially the heave and pitch *** this paper,the numerical method for determining the parametric roll is studied and the results are benchmarked against the model test ***,a 3 degrees-of-freedom(DOF)time domain hybrid panel method is validated by experimental data in regular oblique waves and irregular head ***,the verified 3D O F method is extended to a fully coupled 6 DOF method with the course ***,taking the C11 containership as the test case,the parametric roll in oblique waves is computed,and the effects of the surge,sway and yaw motions on the parametric roll are evaluated with the developed mathematical *** results show that the effects of the surge and sway motions on the parametric roll is insignificant,while the effects of the yaw motion are more *** results of the roll amplitudes and the standard deviation of the roll angles show that the model based on 3 DOF gives relatively conservative results,and can be directly used for the stability assessment of the parametric roll.

关键词： 6DOF mathematical model irregular oblique waves second generation intact stability in IMO

Eigenstates of Laser-Assisted Scattering in a Noninertial Frame

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Communications in Theoretical Physics 2005年第6X期44卷 1002-1006页

作者： FENG Zi-min LI shu-min Department of Modern Physics University of Science and Technology of China P.O. Box 4 Hefei 230026 China

In a rotating noninertial frame, we investigate the eigenstates of the time-dependent problem for electronnucleus scattering assisted by a circularly polarized laser field. Numerical results of probability distribution, quantum potential, and current density are discussed. An approximate expression of scattering cross section for low laser frequency is given.

关键词： noninertial frame laser field scattering eigenstate

Prediction of film ratings based on domain adaptive transfer learning

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High Technology Letters 2023年第1期29卷 98-104页

作者：舒展 duan Yong School of Information Science and Engineering Shenyang University of TechnologyShenyang 110870P.R.China

This paper examines the prediction of film ***,in the data feature engineering,feature construction is performed based on the original features of the film ***,the clustering algorithm is utilized to remove singular film samples,and feature selections are carried *** solving the problem that film samples of the target domain are unlabelled,it is impossible to train a model and address the inconsistency in the feature dimension for film samples from the source ***,the domain adaptive transfer learning model combined with dimensionality reduction algorithms is adopted in this *** the same time,in order to reduce the prediction error of models,the stacking ensemble learning model for regression is also ***,through comparative experiments,the effectiveness of the proposed method is verified,which proves to be better predicting film ratings in the target domain.

关键词： prediction of film rating domain adaptive transfer component analysis(TCA) correlation alignment(CORAL) stacking

Accelerated k-nearest neighbors algorithm based on principal component analysis for text categorization

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Journal of Zhejiang University-Science C(Computers and Electronics) 2013年第6期14卷 407-416页

作者： min DU Xing-shu CHEN School of Computer Science Sichuan University

Text categorization is a significant technique to manage the surging text data on the *** k-nearest neighbors(kNN) algorithm is an effective,but not efficient,classification model for text *** this paper,we propose an effective strategy to accelerate the standard kNN,based on a simple principle:usually,near points in space are also near when they are projected into a direction,which means that distant points in the projection direction are also distant in the original *** the proposed strategy,most of the irrelevant points can be removed when searching for the k-nearest neighbors of a query point,which greatly decreases the computation *** results show that the proposed strategy greatly improves the time performance of the standard kNN,with little degradation in ***,it is superior in applications that have large and high-dimensional datasets.

关键词： k-nearest neighbors(kNN) Text categorization Accelerating strategy Principal component analysis(PCA)

Tribological behaviors of turbofan seal couples from friction heat perspective under high-speed rubbing condition

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Friction 2016年第2期4卷 176-190页

作者： Siyang GAO Weihai XUE Deli duan shu LI Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

The tribological behaviors of two types of seal coatings, nickel-graphite and aluminum-hexagon-boron nitride (Ni-Cg and Al-hBN, respectively) versus a Ti-6Al-4V blade used in turbofan engines were investigated using a high-speed rubbing test. The wear status and damage mechanism of the friction couples were studied and the abradability of the seal coatings was evaluated. By analysis of the coating properties and damage mechanism of the seal couple, the friction heat effect was identified as the key factor influencing blade wear forms as well as coating abradability. A one-dimensional heat conduction model was established to estimate the effect of increasing temperature on the friction interface. The results indicated that in the Ni-Cg and Ti-6Al-4V seal couple, the temperature rising rate (TRR) of the Ti-6Al-4V blade was faster than that of the Ni-Cg coating, and so the Ti-6Al-4V blade softened earlier than the Ni-Cg coating, causing the blade to suffer severe wear. In the Al-hBN and Ti-6Al-4V seal couple, the TRR of the Ti-6Al-4V blade was slower than that of the Al-hBN coating, and so the Al-hBN coating softened first; thus, blade damage was reduced or even replaced by coating adhesion. The square root ratio of thermal diffusivity between the blade and the coating could be taken as an indicator of the ratio of TRR between the blade and coating to predict blade wear status as well as damage mechanism. The results of the model agreed well with the experiment results of the two seal couples used in this study.

关键词： seal coating high-speed rubbing wear mechanism friction heat thermophysical property

Effects of elevated CO_2 concentration on growth and water usage of tomato seedlings under different ammonium/nitrate ratios

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Journal of Environmental Sciences 2007年第9期19卷 1100-1107页

作者： LI Juan ZHOU Jian-min duan Zeng-qiang State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 China. Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing 210008 China.

Increasing atmospheric CO2 concentration is generally expected to enhance photosynthesis and growth of agricultural C3 vegetable crops, and therefore results in an increase in crop yield. However, little is known about the combined effect of elevated CO2 and N species on plant growth and development. Two growth-chamber experiments were conducted to determine the effects of NH4^＋/NO3^- ratio and elevated CO2 concentration on the physiological development and water use of tomato seedlings. Tomato was grown for 45 d in containers with nutrient solutions varying in NH4^＋/NO3^- ratios and CO2 concentrations in growth chambers. Results showed that plant height, stem thickness, total dry weight, dry weight of the leaves, stems and roots, G value （total plant dry weight/seedling days）, chlorophyll content, photosynthetic rate, leaf-level and whole plant-level water use efficiency and cumulative water consumption of tomato seedlings were increased with increasing proportion of NO3- in nutrient solutions in the elevated CO2 treatment. Plant biomass, plant height, stem thickness and photosynthetic rate were 67%, 22%, 24% and 55% higher at elevated CO2 concentration than at ambient CO2 concentration, depending on the values of NH4^＋/NO3^- ratio. These results indicated that elevating CO2 concentration did not mitigate the adverse effects of 100% NH4^＋-N （in nutrient solution） on the tomato seedlings. At both CO2 levels, NH4^＋/NO3^- ratios of nutrient solutions strongly influenced almost every measure of plant performance, and nitrate-fed plants attained a greater biomass production, as compared to ammonium-fed plants. These phenomena seem to be related to the coordinated regulation of photosynthetic rate and cumulative water consumption of tomato seedlings.

关键词： CO2 enrichment NH4^+/NO3^- ratio physiological and biochemical indices growth water use tomato seedling