检索结果-南通市图书馆

A Comparative Study of CNN-and Transformer-Based Visual Style Transfer

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 Computer Science & Technology 2022年第3期37卷 601-614页

作者： Hua-Peng wei Ying-Ying Deng Fan Tang Xing-Jia Pan wei-ming dong School of Artificial Intelligence Jilin UniversityChangchun 130012China National Laboratory of Pattern Recognition Institute of AutomationChinese Academy of SciencesBeijing 100190China Youtu Laboratory Tencent IncorporatedShanghai 200233China

Vision Transformer has shown impressive performance on the image classification *** that most existing visual style transfer(VST)algorithms are based on the texture-biased convolution neural network(CNN),here raises the question of whether the shape-biased Vision Transformer can perform style transfer as *** this work,we focus on comparing and analyzing the shape bias between CNN-and transformer-based models from the view of VST *** comprehensive comparisons,we propose three kinds of transformer-based visual style transfer(Tr-VST)methods(Tr-NST for optimization-based VST,Tr-WCT for reconstruction-based VST and Tr-AdaIN for perceptual-based VST).By engaging three mainstream VST methods in the transformer pipeline,we show that transformer-based models pre-trained on ImageNet are not proper for style transfer *** to the strong shape bias of the transformer-based models,these Tr-VST methods cannot render style *** further analyze the shape bias by considering the influence of the learned parameters and the structure *** prove that with proper style supervision,the transformer can learn similar texture-biased features as CNN *** the reduced shape bias in the transformer encoder,Tr-VST methods can generate higher-quality results compared with state-of-the-art VST methods.

关键词： transformer convolution neural network visual style transfer comparative study

Modeling and simulation of pinhole channels

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2010年第2期17卷 67-71页

作者： wei ming-dong ZHANG Yun-feng ZHANG Ye-rong PAN Zi-yi School of Eleca:onic Science and Engineering Nanjing University of Posts and Teleenmmtmications Nanjing 210003 China Jiangsu Posts and Telecommunications Planning and Designing Institute Co. Ltd Nanjing 210006 China

This article presents a general pinhole channel reference model based on the cause of pinhole effect. On the base of this reference model, a deterministic simulation model is developed by keeping the difference of correlation properties between reference and simulation model as smaller as possible. The correlation properties include temporal autocorrelation fimction （ACF）, two-dimensional （2-D） space cross-correlation function （CCF） and frequency correlation function （FCF）. The results show that although pinhole channel has good correlation properties, the channel capacity is very low because of the low rank of channel transform matrix.

关键词： pinhole channel modeling channel simulation deterministic simulation models

Fast Multi-Operator Image Resizing and Evaluation

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2012年第1期27卷 121-134页

作者： wei-ming dong Guan-Bo Bao Xiao-Peng Zhang Jean-Claude Paul Sino-French Laboratory for Computer Science Automation and Applied Mathematics/National Laboratory of Pattern RecognitionInstitute of AutomationChinese Academy of SciencesBeijing 100190China National Institute for Research in Computer Science and Control Domaine de Voluceau Rocquencourt Le Chesnay 78153France

Current multi-operator image resizing methods succeed in generating impressive results by using image similarity measure to guide the resizing process. An optimal operation path is found in the resizing space. However, their slow resizing speed caused by inefficient computation strategy of the bidirectional patch matching becomes a drawback in practical use. In this paper, we present a novel method to address this problem. By combining seam carving with scaling and cropping, our method can realize content-aware image resizing very fast. We define cost functions combing image energy and dominant color descriptor for all the operators to evaluate the damage to both local image content and global visual effect. Therefore our algorithm can automatically find an optimal sequence of operations to resize the image by using dynamic programming or greedy algorithm. We also extend our algorithm to indirect image resizing which can protect the aspect ratio of the dominant object in an image.

关键词： image resizing multi-operator operator cost indirect resizing

DFT Study on Intermolecular Cleavage Reaction of N-(2-Hydroxyphenyl)-phthalamic Acid

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2008年第6期24卷 790-792页

作者： ZHAO Chu-feng TANG ming-sheng WANG Hong-ming wei dong-hui ZHAO Jing ZHANG Shou-ren CAO Shu-xia Department of Chemistry Zhengzhou University Zhengzhou 450052 P. R. China

The reaction mechanisms of intermolecular cleavage reaction of N-（2-hydroxyphenyl）-phthalamic acid were studied via the density functional theory（DFT）. All geometries of the reactant, transition states, and products were optimized at the B3LYP/6-31G（d, p） level. Vibration analysis was carried out to confirm its identity as transitions＇ structure, and the intrinsic reaction coordinate method（IRC） was used to search the minimum energy path. Two possible reaction channels are reported in this article. The calculated results indicate that O-cyclization reaction channel has the lower activation barrier, and therefore, it occurs more easier than the other.

关键词： Intermolecular decomposition reaction Density functional theory(DFT) O-Cyclization N-Cyclization N-(2-Hydroxyphenyl)-phthalamic acid

An approximate analytical model for unconventional reservoir considering variable matrix blocks and simultaneous matrix depletion

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第1期21卷 352-365页

作者： Kai-Xuan Qiu Jia Li dong Feng Shi-ming wei Gang Lei Jiangmen Laboratory of Carbon Science and Technology Jiangmen529100GuangdongChina The Hong Kong University of Science and Technology(Guangzhou) Guangzhou511400GuangdongChina China University of Geosciences(Beijing) Beijing100083China China University of Petroleum(Beijing) Beijing102249China China University of Geosciences(Wuhan) Wuhan430074HubeiChina Shenzhen Research Institute China University of GeosciencesShenzhen518063GuangdongChina

In regard to unconventional oil reservoirs,the transient dual-porosity and triple-porosity models have been adopted to describe the fluid flow in the complex fracture *** has been proven to cause inaccurate production evaluations because of the absence of matrix-macrofracture *** addition,most of the existing models are solved analytically based on Laplace transform and numerical ***,an approximate analytical solution is derived directly in real-time space considering variable matrix blocks and simultaneous matrix *** simplify the derivation,the simultaneous matrix depletion is divided into two parts:one part feeding the macrofractures and the other part feeding the ***,a series of partial differential equations(PDEs)describing the transient flow and boundary conditions are constructed and solved analytically by ***,a relationship between oil rate and production time in real-time space is *** new model is verified against classical analytical *** the microfracture system and matrix-macrofracture communication is neglected,the result of the new model agrees with those obtained with the dual-porosity and triple-porosity model,***,the new model also has an excellent agreement with the numerical *** model is then applied to two actual tight oil wells completed in western Canada sedimentary *** identifying the flow regime,the solution suitably matches the field production data,and the model parameters are *** these output parameters,we can accurately forecast the production and even estimate the petrophysical properties.

关键词： Analytical solution Unconventional reservoir Variable matrix Simultaneous flow

Synergistic Brønsted Base/Photoredox-Catalyzed Three-Component Coupling with Malonates to Synthesize δ-Hydroxy Esters and δ-Keto Esters

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第9期42卷 957-962页

作者： Ting Li wei Wang ming dong Zhije Zhang Sha Yu Zhengchu Chen Siping wei dong Yi Green Pharmaceutical Technology Key Laboratory of Luzhou City Central Nervous System Drug Key Laboratory of Sichuan ProvinceSchoolof PharmacySouthwestMedicalUniversityLuzhouSichuan 646000China Nuclear Medicine and Molecular Imaging Key Laboratory of Sichuan Province LuzhouSichuan 646000China

Multicomponent alkene 1,2-dicarbofunctionalizations(DCFs)have emerged as a powerful strategy to rapidly incorporate both two carbon subunits across one C-C double bond in one step for enhancing molecular complexity and *** the best of our knowledge,there is only one report on photoredox-catalyzed three-component DCFs with malonates through the radical−radical cross-coupling,while photoredox-catalyzed radical-polar crossover(RPC)-type DCFs with malonates were still ***,we describe a redox-neutral RPC-type 1,2-dialkylation of styrenes with malonates and aldehydes through the synergistic Brønsted base/photoredox catalysis *** transition-metal-free strategy provides an efficient and clean approach to a broad variety ofδ-hydroxy esters and also features exceptionally mild conditions,wide compatibility of substrate scope and functional groups,and high atomic ***,three-component 1,2-alkylacylation from the same starting materials was achieved in one-pot manner through such RPC-type coupling and subsequent two-electron oxidation process,providing a set ofδ-keto esters of interest in pharmaceutical research.

关键词： Alkene difunctionalization Photoredox catalysis Malonates Radical reactions C-C coupling Synthetic methods Aldehydes Alkylation Multicomponentreactions

Quality assessment of friction-stir-welded aluminum alloy welds via three-dimensional force signals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Manufacturing 2024年第1期12卷 61-75页

作者： Ji-Hong dong Yi-ming Huang Jia-Lei Zhu wei Guan Xu-Kai Ren Huan-wei Yu Lei Cui Beijing Institute of Petrochemical Technology Beijing102617People’s Republic of China Beijing Academy of Safety Engineering and Technology Beijing102617People’s Republic of China AVIC Manufacturing Technology Institute Beijing100024People’s Republic of China Tianjin Key Laboratory of Advanced Joining Technology School of Materials Science and EngineeringTianjin UniversityTianjin300350People’s Republic of China Shaoxing Special Equipment Testing Institute Shaoxing Key Laboratory of Special Equipment Intelligent Testing and EvaluationShaoxing312071ZhejiangPeople’s Republic of China

An online detection technology must be developed for realizing the real-time control of friction stir *** this study,the three-dimensional force exerted on a material during friction stir welding was collected synchronously and the relationship between the forces and welding quality was *** results indicated that the fluctuation period of the traverse force was equal to that of the lateral force during the stable welding *** phase difference between two horizontal forces wasπ/*** values of the horizontal forces increased with welding speed,whereas their amplitudes remained the *** proposed force model showed that the traverse and lateral forces conformed to an elliptical curve,and this result was consistent with the behavior of the measured *** variational mode decomposition was used to process the plunge *** intrinsic mode function that represented the real fluctuation in the plunge force varied at the same frequency as the spindle rotational *** tunnel defects occurred,the fluctuation period features were consistent with those obtained during normal welding,whereas the ratio parameter defined in this study increased significantly.

关键词： Friction stir welding(FSW) Three-dimensional force model Variational mode decomposition Tunnel defect

Development characteristics and controlling factors of fractures in lacustrine shale and their geological significance for evaluating shale oil sweet spots in the third member of the Shahejie Formation in the Qikou Sag, Bohai Bay Basin

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第2期21卷 791-805页

作者： Xu Zeng Tao Yang Jian-wei Feng Cong-Sheng Bian ming Guan wei Liu Bing-Cheng Guo Jin dong Research Institute of Petroleum Exploration and Development China National Petroleum CorporationBeijing100083China College of Geosciences China University of Petroleum(Beijing)Beijing102249China Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China School of Earth Sciences China University of PetroleumQingdao266400ShandongChina

Natural fractures are critical for shale oil and gas enrichment and development. Due to the extremely high heterogeneity of shale, the factors controlling the formation of internal fractures, especially horizontal fractures, remain controversial. In this study, we integrate thin section analysis and microcomputed tomography(CT) data from several lacustrine shale samples from the third member(Es3) of the Shahejie Formation, Qikou Sag, Bohai Bay Basin, to assess the fractures in detail. The goal is to reveal the development characteristics, controlling factors, and geological significance for evaluating sweet spots in a shale oil play. The fractures in the Es3contain high-angle structural and horizontal bed-parallel fractures that are mostly shear and extensional. Various factors influence fracture development,including lithofacies, mineral composition, organic matter content, and the number of laminae. Structural fractures occur predominantly in siltstone, whereas bed-parallel fractures are abundant in laminated shale and layered mudstone. A higher quartz content results in higher shale brittleness, causing fractures, whereas the transformation between clay minerals contributes to the development of bedparallel fractures. Excess pore pressure due to hydrocarbon generation and expulsion during thermal advance can cause the formation of bed-parallel fractures. The density of the bed-parallel and structural fractures increases with the lamina density, and the bed-parallel fractures are more sensitive to the number of laminae. The fractures are critical storage spaces and flow conduits and are indicative of sweet spots. The laminated shale in the Es3with a high organic matter content contains natural fractures and is an organic-rich, liquid-rich, self-sourced shale play. Conversely, the siltstone, massive mudstone, and argillaceous carbonate lithofacies contain lower amounts of organic matter and do not have bed-parallel fractures. However, good reservoirs can form in th

关键词： Fractures Development characteristics Controlling factors Shale oil Sweet spot

Rational design of superior catalysts from topological semimetals with nontrivial energy window

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第5期43卷 1956-1964页

作者： Min Zhao Li-Rong Wang wei Liu ming-Hang Li Ying Liu Xue-Fang Dai Guo-dong Liu Xiao-ming Zhang Key Laboratory of Reliability and Intelligence of Electrical Equipment School of Materials Science and Engineering ManufacturingHebei University of TechnologyTianjin 300130China

Materials featuring topological energy bands and nontrivial surface states hold significant promise in unlocking unprecedented opportunities for innovating electrocatalytic ***,it remains a challenge to realize superior topological catalysts which can carry both high catalytic activity and excellent catalytic ***,we propose that a family of Ni-based binary materials hosting fantasying topological conjunct-nodalpoint state and a large nontrivial energy window(NEWD)represents an ideal choice for such superior topological catalysts in hydrogen evolution *** presence of conjunct-nodal-points ensures long Fermi arcs on the surface,thereby enabling an extremely high catalytic *** NEWD plays a crucial role in stabilizing the high catalytic activity against external perturbations,such as strain and electron/hole *** roles for conjunctnodal-points and NEWD are substantiated by the observable weakening of catalytic performance during topological phase transitions,which result in the removal of the conjunct-nodal-points,NEWD and their corresponding long Fermi *** work unveils a hidden mechanism and opens a feasible route for developing superior quantum catalysts from novel topology point of view.

关键词： First-principles modeling Topological semimetal Nontrivial surface states Hydrogen evolution reaction