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Formation and causes of NOx pollution on the east side of the Taihang Mountains in China

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science Bulletin 2011年第19期 2046-2051页

作者： TIAN HeZhong 1 , WANG Yan 1 , ZHAO Dan 1 , CHAI FaHe 2 , XING ZiShan 3 & CHENG Ke 1 1 State Key Joint Laboratory of Environmental Simulation & Pollution Control, school of Environment, beijing Normal university, beijing 100875, China 2 Chinese Research Academy of Environmental {4.s, beijing 100012, China 3 school of Computer {4. and Technology, beijing university of posts and telecommunications, beijing 100876, China

Tropospheric column amounts of NO 2 from OMI/Aura products were applied to investigate the seasonal variation of NO x on the east side of the Taihang Mountains (ESTM) in China. The NO 2 concentration varied seasonally, with winter maxima and summer minima. To explore the causes of the heavy NO 2 pollution in this region, wind field simulations were conducted by using the Fifth-Generation NCAR/Penn State Mesoscale Model (MM5). MM5 simulations showed that wind directions in the ESTM region were dominated by northeasterly and northwesterly winds throughout the year and to a lesser degree by southwesterlies. Elevated NO 2 concentrations (higher than 50×10 15 molec/cm 2 ) occurred in three meteorological situations: convergent wind fields (5 days), northeasterly winds (2 days), and calm days (1 day) in January. Although the local anthropogenic NO x emission strength was not so high as that in other developed areas, the calms and frequent occurrence of convergent wind fields, as well as unfavorable terrains for diffusion, resulted in the accumulation of atmospheric pollutants and hence heavy NO x pollution. Furthermore, long-distance NO x transportation from the beijing-Tianjin-Tangshan region to the ESTM area could be seen when the wind was from a northeasterly direction, especially under high wind speeds.

关键词： east side of the Taihang Mountains (ESTM) remote sensing of air pollution satellite data tropospheric NO 2 pollution wind field China

Bit Constraints Analysis of Multihop All-Optical Networks with Deflection Routing

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Chinese Journal of Lasers 1998年第4期 81-88页

作者： XIE Chongjin YE Peida (P. O. Box 57, school of Telecommunication Engineering, beijing university of posts and telecommunications, beijing 100876, China)

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１ＩｎｔｒｏｄｕｃｔｉｏｎＴｏｏｖｅｒｃｏｍｅｔｈｅｅｌｅｃｔｒｏｎｉｃｂｏｔｌｅｎｅｃｋｏｆｃｏｎｖｅｎｔｉｏｎａｌｏｐｔｉｃａｌｐａｃｋｅｔｓｗｉｔｃｈｉｎｇｎｅｔｗｏｒｋｓ，ａｌｏｐｔｉｃａｌｐａｃｋｅｔｓｗｉｔｃｈｉｎｇｎｅｔｗｏｒｋｓａｒｅ...

关键词： all optical networks deflection routing soliton linear systems

Product Positioning Game of Oligarchs in 3G Telecom Market

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Product Positioning Game of Oligarchs in 3G Telecom Market

2009中国控制与决策会议

作者： Chen Dehua~1,Tang Shoulian~2 1.school of Economics & Management,beijing university of posts and telecommunications,beijing 100876 2.school of Economics & Management,beijing university of posts and telecommunications,beijing 100876

＜正＞With the 3G-era coming,the competition in mobile communications market will increase *** author first analyzed the product differentiation play an important role to oligarchs’ profits,according to comparing the Cournot Model under with the Cournot Model which revised by Bowley *** this basis,the author analyzed the Stackelberg competitive equilibrium of three oligarchs in 3G market under cost asymmetry,given the competitive equilibrium of simultaneous determination or asynchronous determination in second stage,then compared with the competitive equilibrium results which revised by Bowley *** the author proposed that product differentiation strategy will be the inevitable choice for three oligarchs in 3G market *** put forward the differentiation strategy as consequence.

关键词： 3G Cournot Model Stackelberg Model Positioning Differentiation Bowley Model

A Simple Capacity Formula for Correlated Diversity Rayleigh Fading Channels

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The Journal of China Universities of posts and telecommunications 2004年第z1期11卷 37-39页

作者： CHENG Xing-qing~1, SU Shu-chun~2, LI Dao-ben~1 1.beijing university of posts and telecommunications,beijing 100876, P.R. China 2.beijing Electronic science Technology Institute,beijing 100070, P.R. China beijing university of posts and telecommunications Beijing 100876 P.R. China

The system capacity can be considerably increased if we appropriately exploit the randomness of multipath propagation. A simple average capacity formula is derived for correlated diversity Rayleigh fading channels through linear transformation method. Numerical results that illustrate the effect of correlation parameter and diversity order on the diversity capacity are also presented.

关键词： channel capacity fading channel and wireless SIMO systems

A variable-coefficient unstable nonlinear Schrdinger model for the electron beam plasmas and Rayleigh-Taylor instability in non-uniform plasmas: Solutions and observable effects

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A variable-coefficient unstable nonlinear Schrdinger model...

2003’全国流体力学青年研讨会

作者： Yi-Tian Gao and Bo Tian school of Aeronautic science and Technology,beijing university of Aeronautics and Astronautics,beijing 100083,China school of science,beijing university of posts and telecommunications,beijing 100876,China

＜正＞ A variable-coefficient unstable nonlinear Schrodinger model is hereby investigated, which arises in such applications as the electron-beam plasma waves and Rayleigh-Taylor instability in non-uniform, plasmas. With computerized symbolic computation, families of exact analytic dark- and bright-soliton-like solutions are found, along with similarity solutions. Some observable effects caused by the variable coefficient are predicted, which may be detected in the future with the relevant space or laboratory plasma experiments with non-uniform background existing. The full text of this paper will appear in Phys. Plasmas, Vol. 10, Iss. 11, Nov., 2003.

关键词： Variable-coefficient unstable nonlinear Schrodinger model Electron beam plasmas Rayleigh-Taylor instability Non-uniform plasmas Analytic soliton-like solutions Similarity solutions Observable effects

Inferring playback rate and rate resets of P2P video streaming transmissions by piecewise line envelope approximation

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The Journal of China Universities of posts and telecommunications 2009年第2期16卷 58-62,79页

作者： LI Chun-xi CHEN Chang-jia school of Electronics and Information Engineering,beijing Jiaotong university,beijing 10004.,China [a]school of Electronics and Information Engineering beijing Jiaotong university beijing 10004. China

Conventionally, P2P video is regarded as CBR traffic. However, our measurements have shown that the rate reset cannot be neglected in a practical IPTV system because each rate reset often leads to performance degradation. Thus, addressing the problem of inferring playback rate and rate reset in a P2P video system is significant. In this article, an algorithm termed piecewise linear envelope approximation （PLEA） is proposed, in which a follow-up time is introduced to smooth rate fluctuations in a small time scale and to adapt rate jumps in a large time scale automatically. With the PLEA algorithm, discontinuity introduced by blind segmentations adopted by current methods is avoided. Furthermore, unlike existing algorithms in which both segmentation and combinations are performed in multiple runs, only a single computation path is involved in the PLEA algorithm. This makes PLEA algorithm amenable to implementation of low complexity by either software or hardware. Both theoretical analysis and experiment based on measured data show that the PLEA outperforms existing algorithms based on segmentation.

关键词： P2P video playback rate rate reset convex hull linear program

Offline Urdu Nastaleeq Optical Character Recognition Based on Stacked Denoising Autoencoder

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China Communications 2017年第1期14卷 146-157页

作者： Ibrar Ahmad Xiaojie Wang Ruifan Li Shahid Rasheed Center for Intelligence of science and Technology (CIST) School of Computer ScienceBeijing University of Posts and Telecommunications No. 10 Xitucheng Road Beijing 100876 China Department of Computer science University of Peshawar Peshawar 25120 Pakistan Pakistan Telecommunication Company Limited (PTCL) Islamabad 44000 Pakistan

Offline Urdu Nastaleeq text recognition has long been a serious problem due to its very cursive nature. In order to get rid of the character segmentation problems, many researchers are shifting focus towards segmentation free ligature based recognition approaches. Majority of the prevalent ligature based recognition systems heavily rely on hand-engineered feature extraction techniques. However, such techniques are more error prone and may often lead to a loss of useful information that might hardly be captured later by any manual features. Most of the prevalent Urdu Nastaleeq test recognition was trained and tested on small sets. This paper proposes the use of stacked denoising autoencoder for automatic feature extraction directly from raw pixel values of ligature images. Such deep learning networks have not been applied for the recognition of Urdu text thus far. Different stacked denoising autoencoders have been trained on 178573 ligatures with 3732 classes from un-degraded(noise free) UPTI(Urdu Printed Text Image) data set. Subsequently, trained networks are validated and tested on degraded versions of UPTI data set. The experimental results demonstrate accuracies in range of 93% to 96% which are better than the existing Urdu OCR systems for such large dataset of ligatures.

关键词： offline printed ligature recognition urdu nastaleeq denoising autoencoder deep learning classification

Correlation-based K-Nearest Neighbor Algorithm

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Correlation-based K-Nearest Neighbor Algorithm

2012 IEEE 3rd International Conference on Software Engineering and Service science（ICSESS 2012）

作者： Xinran Li International school beijing university of posts and telecommunications beijing ChinaChenhui Xiang International school beijing university of posts and telecommunications beijing China

Data classification is an important task of data mining,and developing high-powered classification algorithm is one of the key procedures for data *** paper provides an improved K-nearest neighbor algorithm-correlation-based K-nearest neighbor *** new algorithm makes data classification base on the correlation calculation,and uses a modified probability to improve the computational speed and prediction *** experimental results show that the correlation-based K-nearest neighbor algorithm is more suitable to classify massive high-dimensional data sets while comparing with traditional K-nearest neighbor algorithm.

关键词： component K-nearest neighbor algorithm correlation data classification

Generalized Distributed Multicell Architecture:Group Cell

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ZTE Communications 2006年第2期4卷 7-10页

作者： Tao Xiaofeng Wu Chunli Xu Xiaodong (WTI, beijing university of posts and telecommunications, beijing 100876, China)

In order to make full use of advanced technologies for future mobile communications systems such as Space Time Code (STC), Joint Transmission (JT) and Multiple Input Multiple Output (MIMO), and to meet the requirements of high-bit-rate multimedia services, new network topologies should be studied. Generalized distributed multicell architecture can take full advantage of multi-antenna technologies and solve the problem of frequent handover caused by higher carrier frequencies. Group handover, the handover policy based on the architecture, can eliminate the cell edge effect. Furthermore, by applying the concept of group handover to 3G mobile communication systems, the Fast Cell Group Selection (FCGS) scheme can effectively improve the data rate for cell edge users.

关键词： Figure cell IEEE Radio USA Generalized Distributed Multicell Architecture more GPP MT