检索结果-南通市图书馆

Adaptive sampling for mesh spectrum editing

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 Zhejiang University-Science A(Applied Physics & Engineering) 2006年第7期7卷 1193-1200页

作者： ZHAO Xiang-jun ZHANG Hong-xin BAO Hu-jun State Key Lab of CAD ＆ CG Zhejiang University Hangzhou 310027 China College of Computer Science and Engineering Xuzhou Normal University Xuzhou 221116 China

A mesh editing framework is presented in this paper, which integrates Free-Form Deformation (FFD) and geometry signal processing. By using simplified model from original mesh, the editing task can be accomplished with a few operations. We take the deformation of the proxy and the position coordinates of the mesh models as geometry signal. Wavelet analysis is em- ployed to separate local detail information gracefully. The crucial innovation of this paper is a new adaptive regular sampling approach for our signal analysis based editing framework. In our approach, an original mesh is resampled and then refined itera- tively which reflects optimization of our proposed spectrum preserving energy. As an extension of our spectrum editing scheme, the editing principle is applied to geometry details transferring, which brings satisfying results.

关键词： Mesh editing Adaptive sampling Digital geometry processing

Reduce the decoding complexity: segment linear network coding

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2013年第6期20卷 55-61页

作者： GUO Yi-jun HAO Jian-jun YUE Guang-xin School of Telecommunication Engineering Beijing University of Posts and Telecommunications

The throughput gain obtained by linear network coding （LNC） grows as the generation size increases, while the decoding complexity also grows exponentially. High decoding complexity makes the decoder to be the bottleneck for high speed and large data transmissions. In order to reduce the decoding complexity of network coding, a segment linear network coding （SLNC） scheme is proposed. SLNC provides a general coding structure for the generation-based network coding. By dividing a generation into several segments and restraining the coding coefficients of the symbols within the same segment, SLNC splits a high-rank matrix inversion into several low-rank matrix inversions, therefore reduces the decoding complexity dramatically. In addition, two coefficient selection strategies are proposed for both centrally controlled networks and distributed networks respectively. The theoretical analysis and simulation results prove that SLNC achieves a fairly low decoding complexity at a cost of rarely few extra transmissions.

关键词： SLNC generation-based network coding random LNC decoding complexity extra transmission cost

A Finite-Dimensional Completely Integrable System Associated with Boussinesq Hierarchy

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2009年第12期52卷 1081-1086页

作者： CHEN Lan-xin ZHANG jun-Xian China University of Mining and Technology Beijing 100083 China Shijiazhuang University Shijiazhuang 050035 China

In this paper, a new completely integrable system related to the complex spectral problem -φ xx＋（i/4）wpx＋（i/4）（wp）x＋（1/4）vφ=iλφxand the constrained flows of the Boussinesq equations axe generated. According to the viewpoint of Hamiltonian mechanics, the Euler-Lagrange equations and the Legendre transformations, a reasonable Jacobi-Ostrogradsky coordinate system is obtained. Moreover, by means of the constrained conditions between the potentiaJ u, v and the eigenfunction φ, the involutive representations of the solutions for the Boussinesq equation hieraxchy axe given.

关键词： eigenvalue problem constraint flow symplectic manifold completely integrability involutive representation

Speed Distributions of CMEs in Cycle 23 at Low and High Latitudes

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Astronomy and Astrophysics 2008年第2期8卷 146-152页

作者： Peng-xin Gao Ke-jun Li National Astronomical Observatories / Yunnan Observatory Chinese Academy of Sciences Kunming 650011 GraduateSchool of Chinese Academy of Sciences Beijing 100049

We analyzed the speed （v） distributions of 11584 coronal mass ejections （CMEs） observed by the Large Angle and Spectrometric Coronagraph Experiment on board the Solar and Heliospheric Observatory （SOHO/LASCO） in cycle 23 from 1996 to 2006. We find that the speed distributions for high-latitude （HL） and low-latitude （LL） CME events are nearly identical and to a good approximation they can be fitted with a lognormal distribution. This finding implies that statistically the same driving mechanism of a nonlinear nature is acting in both HL and LL CME events, and CMEs are intrinsically associated with the source＇s magnetic structure on large spatial scales. Statistically, the HL CMEs are slightly slower than the LL CMEs. For HL and LL CME events respectively, the speed distributions for accelerating and decelerating events are nearly identical and also to a good approximation they can be both fitted with a lognormal distribution, thus supplementing the results obtained by Yurchyshyn et al.

关键词： Sun activity -- Sun coronal mass ejections (CMEs)

On the Global Existence and Uniqueness of Solutions to Prandtl's System

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2009年第1期25卷 109-132页

作者： xin Ying XU jun Ning ZHAO Department of Mathematics Xiamen University Xiamen Fujian 361005 P. R. China

In this paper, we consider the Prandtl system for the non-stationary boundary layer in the vicinity of a point where the outer flow has zero velocity. It is assumed that U（t, x, y） = x^mU1（t, x）, where 0 〈 x 〈 L and m 〉 1. We establish the global existence of the weak solution to this problem. Moreover the uniqueness of the weak solution is proved.

关键词： boundary layer global solution uniqueness

China＇s nuclear power under the global 1.5℃ target： Preliminary feasibility study and prospects

在线全文

学校读者我要写书评

暂无评论

Advances in Climate Change Research 2018年第2期9卷 138-143页

作者： XIAO xin-Jian JIANG Ke-jun Energy Research Institute National Development and Reform Commission Beijing 100038 China

This study explores the measures to achieve the global 1.5 ℃ temperature rise target （1.5 ℃ target） by analyzing the feasibility and obstacles of nuclear power in China. The 1.5 ℃target imposes stricter requirements on China＇s nuclear power. Considering the available nuclear power plant sites, nuclear power layout, equipment manufacture ＆ supply, nuclear power plant construction capacity, supportive operation ＆ management talents, investment, cost effectiveness, and public acceptance, the achievement of the development objectives of nuclear power in China considering the 1.5 ℃ Target is difficult. However, it is possible if favorable decisions and policies are made.

关键词： 1.5 ℃ target Nuclear power in China Solutions Feasibility Decision-making

Study of the Electromagnetic Scattering from the Very Rough Fractal Sea Surface

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 2003年第1X期40卷 95-100页

作者： GUOLi-xin CHENJian-jun WUZhen-Sen SchoolofScience XidianUniversityXi'an710071China

In this paper, based on the fundamental formulae of the first-order and second-order Kirchhoff approx-imation mad with consideration of the shadowing effect, the backscattering enhancement of the one-dimensional very rough fractal sea surface with Pierson-Moskowitz spectrum is studied under the second-order Kirchhoff approximation at microwave frequency. The numerical results are compared with those of the first-order Kirchhoff approximation and integral equation method. The dependencies of the bistatic scattering cross section and the backscattering enhancement on the incident angle, fractal dimension, and windspeed over the sea surface are analyzed in detail.

关键词：电磁散射二次基尔霍夫近似反向散射增加粗糙分形大海表面

Finite Groups with Its Power Automorphism Groups Having Small Indices

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2009年第7期25卷 1097-1108页

作者： jun xin WANG Xiu Yun GUO Department of Mathematics Shanxi University of Finance and Economics Taiyuan 030006 P.R. China Department of Mathematics Shanghai University Shanghai 200444 P.R.China

In this paper, a finite group G with IAut（G）： P（G）I ^- p or pq is determined, where P（G） is the power automorphism group of G, and p, q are distinct primes. Especially, we prove that a finite group G satisfies ｜Aut（G）： P（G）｜= pq if and only if Aut（G）/P（G） ≌S3. Also, some other classes of finite groups are investigated and classified, which are necessary for the proof of our main results.

关键词： power automorphism group norm action

The Development and Evolution of Community Mental Health Policies in China from 1998 to 2013

在线全文

学校读者我要写书评

暂无评论

China CDC weekly 2023年第40期5卷 900-908页

作者： jun Yan xin Yu Xiulan Zhang Chinese Center for Disease Control and Prevention BeijingChina Institute of Mental Health Peking UniversityBeijingChina Beijing Normal University BeijingChina

This paper presents a detailed analysis of the development and evolution of community mental health policies in China,from their reestablishment in 1998 to the establishment and implementation of the“Mental Health Law of the People’s Republic of China”in *** development of these policies across a 15-year period is segmented into three distinct phases,each characterized by a thorough exposition and an encompassing *** paper scrupulously reviews and elucidates the crucial occurrences in each phase,emphasizing the significant impact of the prevailing conditions on the progression of policy *** paper concludes by sharing insights acquired from the policy development *** this framework,community mental health policies entail a myriad of legislations,strategies,methodologies,protocols,regulations,and ordinances,instituted by national governance to enhance the proliferation of community-based mental health services.

关键词： policy prevailing Evolution