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Quantum Phase Transition of the Bosonic Atoms near the Feshbach Resonance in an Optical Lattice

Chinese Physics Letters 2010年第12期27卷 65-68页

作者：李犇陈景标 Institute of Quantum Electronics and State Key Laboratory of Advanced Optical Communication System ~z Network School of Electronics Engineering & Computer Science Peking University Beijing 100871

The quantum phase transition from the Mott insulator to the superfluid phases of the bosonic atoms trapped in an optical lattice, in which the on-site interaction carl be tuned by a Feshbach resonance, is investigated by a variational approach within mean-field theory. We derive an extended Bos^Hubbard model to describe this ultracold atomic system. By theoretical calculation and analysis, the phase diagram is shown clearly, and we find an exciting and novel phenomenon that is the appearance of the Mort insulator-sea （MI-sea）. Meanwhile, the experimental feasibility of observing the MI-sea is discussed by analyzing the published data related to the Fashbaeh resonance at present. Finally, the potential application of the MI-sea for quantum information processing and quantum computation is also discussed in detail

关键词： Atomic and molecular physics Quantum gases, liquids and solids Computational physics Statistical physics and nonlinear systems

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Magic Wavelengths for a Lattice Trapped Rubidium Four-Level Active Optical Clock

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Chinese Physics Letters 2012年第9期29卷 24-27页

作者： ZANG Xiao-Run ZHANG Tong-Gang CHEN Jing-Biao Institute of Quantum Electronics and State Key Laboratory of Advanced Optical Communication System&NetworkSchool of Electronics Engineering and Computer SciencePeking UniversityBeijing 100871

After being pumped from the 5s_(1/2) ground state to the 6p_(1/2) state,the population inversion between 6s_(1/2) and 5p_(1/2,3/2) can be established for a rubidium four-level active optical *** calculate the ac Stark shift due to lattice trapping laser which dominates the frequency shift of clock transition in a lattice trapped rubidium four-level active optical *** magic wavelengths are found,which can form desired optical lattice trapping *** choosing a proper intensity and linewidth of the trapping laser,the fractional frequency uncertainty of clock transition due to the ac Stark shift of the trapping laser,is estimated to be below 10^(−18).

关键词： pumped trapping Magic

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Cs 455nm Nonlinear Spectroscopy with Ultra-narrow Linewidth

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Chinese Physics Letters 2013年第6期30卷 50-52页

作者： WANG Dong-Ying WANG Yan-Fei TAO Zhi-Ming ZHANG Sheng-Nan HONG Ye-Long ZHUANG Wei CHEN Jing-Biao State Key Laboratory of Advanced Optical Communication System and Network Institute of Quantum ElectronicsSchool of Electronics Engineering&Computer SciencePeking UniversityBeijing 100871

Nonlinear spectroscopy has become a useful tool in laser cooling,frequency stabilization and so *** use the 455.5 nm light beam output of an external cavity diode laser to perform the saturation spectroscopy signal and polarization spectroscopy signal on the 6S_(1/2)→7P3/2 transition in *** measured linewidth of the F4→4,5 transition is as narrow as 1.40 MHz and that of the F3→2,3 transition is 1.67 *** of them are very close to the natural linewidth of about 1.2 *** result is the narrowest measured linewidth of Cs 455 nm saturation spectroscopy signal to our knowledge.

关键词： polarization narrow signal

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STUDY ON NONLINEAR DYNAMICS OF TCP-RENO TRAFFIC UNDER RED

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Journal of Pharmaceutical Analysis 2006年第1期18卷 21-23,27页

作者：王立李增智薛可 Institute of Computer System Architecture & Network Xi'an Jiaotong UniversityXi'an 710049China

A discrete time feedback control system model based on a multi-router network has been presented. The model can be described by a set of recurrence equations. The numerical examples about the bifurcation of average and instantaneous queue size along with the variety of RED control parameter are shown. The simulate experiments about those of the RED control parameters are also presented. All of these results show that instability in TCP-Reno traffic under RED can be induced by the inherent nonlinear behavior of the network.

关键词： service management nonlinear dynamics TCP-Reno RED

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Case base maintenance based on outlier data mining

Case base maintenance based on outlier data mining

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International Conference on Machine Learning and Cybernetics, ICMLC 2005

作者： Ni, Zhi-Wei Liu, Yu Li, Feng-Gang Yang, Shan-Lin Institute of Computer Network System Hefei University of Technology Hefei 230009 China

ISBN: (纸本)078039092X

In case-based reasoning (CBR) system, as the scale of case base is enlarging, the system performance is gradually dropping. This paper mainly discusses how to maintain case bases in CBR system by adopting outlier data mining and case sieving techniques. Experimental results have shown that the proposed algorithm can maintain case bases satisfactorily and stably, thus assuring the good performance of CBR system. © 2005 IEEE.

关键词： Data mining

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Study on visualization of spatial data mining and knowledge discovery

Study on visualization of spatial data mining and knowledge ...

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International Conference on Space Information Technology

作者： Yang, Shanlin Li, Yongsen Zhang, Shuchu Bai, Hao Institute of Computer Network System Hefei University of Technology Hefei 230009 China

ISBN: (纸本)0819460079

Spatial data usually show as vector maps or raster images. The vector maps are composed of points, lines and polygons, while raster images are composed of grids. Spatial data have different character from common data, which makes it difficult to find knowledge from spatial database than from common database. Spatial Data Mining and Knowledge discovery (SDMKD) is considered as an advanced process to extract novel and interesting models from spatial database. However, visualization is a technique which can deal with substantive data and show this process as figures, images and charts by computers. But, SDMKD and visualization always keep separate and develop independently. A basic and important problem about visualization supporting SDMKD is seldom concerned. To make the process of SDMKD efficient and intuitional, this paper has a preliminary study on visualization of SDMKD through a mutual operation between the human and the computer. It realizes the visualization of data rebuilding and the process of data mining. Some techniques of visualization are used such as charts, maps, figures and images.

关键词： Data mining

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Experimental Scheme of 633 nm and 1359 nm Good-Bad Cavity Dual-Wavelength Active Optical Frequency Standard

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Chinese Physics Letters 2015年第8期32卷 57-61页

作者：许志超潘多庄伟陈景标 State Key Laboratory of Advanced Optical Communication System and Network Institute of Quantum Electronics School of Electronics Engineering & Computer Science Peking University Beijing 100871 National Institute of Metrology Beijing 100013

The experimental scheme of 633 nm and 1359 nm good-bad cavity dual-wavelength active optical frequency stan- dard is proposed, where He-Ne 633nm and Cs 1359nm stimulated emissions are working at good-cavity and bad-cavity regimes, respectively. The cavity length is stabilized by locking the 633nm output frequency to a super-cavity with the Pound Drever-Hall （PDH） technique. The frequency stability of 1359 nm bad-cavity stim- ulated emission output is then expected to be further improved by at least 1 order of magnitude than the 633nm PDH system due to the suppressed cavity pulling effect of active optical clock, and the quantum limited linewidth of 1359nm output is estimated to be 72.5 mHz.

关键词： length Experimental Scheme of 633 nm and 1359 nm Good-Bad Cavity Dual-Wavelength Active Optical Frequency Standard

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Agent Modeling of User Preferences Based on Fuzzy Classified ANNs in Automated Negotiation

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Journal of Donghua University(English Edition) 2011年第1期28卷 45-48页

作者：顾铁军汤兵勇马溪骏李毅 Glorious Sun School of Business and Management Donghua University Institute of Computer Network System Hefei University of Technology Information Security System Testing Lab The Third Research Institute of Ministry of Public Security

In agent-based automated negotiation research area,a key problem is how to make software agent more adaptable to represent user preferences or suggestions,so that agent can take further proposals that reflect user requirements to implement ecommerce activities like automated *** difficulty lies in the uncertainty of user preferences that include uncertain description and contents,non-linear and dynamic *** this paper,fuzzy language was used to describe the uncertainty and combine with multiple classified artificial neural networks(ANNs) for self-adaptive learning of user *** refinement learning results of various negotiation contracts' satisfaction degrees in the extent of fuzzy classification can be *** to unclassified computation,the experimental results illustrate that the learning ability and effectiveness of agents have been improved.

关键词： agent automated negotiation user modeling artificial neural network(ANN) fuzzy classification

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Research and improvement on packet capture mechanism in linux for high-speed network

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Journal of Harbin institute of Technology(New Series) 2005年第5期12卷 494-498页

作者：杨武方滨兴云晓春张宏莉 School of Computer Science and Technology Harbin Institute of Technology Harbin 150001China National Computer Network and Information System Security Administration Center Beijing 100031China

With the increasing enlargement of network scale and the rapid development of network techniques, large numbers of the network applications begin to appear. Packet capture plays an important role as one basic technique used in each field of the network applications. In a high-speed network, the heavy traffic of network transmission challenges the packet capture techniques. This paper does an in-depth analysis on the traditional packet capture mechanisms in Linux, and then measures the performance bottleneck in the process of packet capture. The methods for improving the packet capture performance are presented and an optimized packet capture scheme is also designed and implemented. The test demonstrates that the new packet capture mechanism (Libpacket) can greatly improve the packet capture performance of the network application systems in a high-speed network.

关键词： high-speed network packet capture TCP/IP protocol stack performance bottleneck LKM

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Joint Design of Radar Receive Filter and Unimodular ISAC Waveform with Sidelobe Level Control

arXiv

引用

arXiv 2025年

作者： Zhang, Kecheng Liu, Ya-Feng Wang, Zhongbin Yuan, Weijie Keskin, Musa Furkan Wymeersch, Henk Xia, Shuqiang School of System Design and Intelligent Manufacturing The Shenzhen Key Laboratory of Robotics and Computer Vision Southern University of Science and Technology Shenzhen518055 China State Key Laboratory of Scientific and Engineering Computing Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing100190 China Department of Electrical Engineering Chalmers University of Technology Gothenburg41296 Sweden ZTE Corporation The State Key Laboratory of Mobile Network and Mobile Multimedia Technology Shenzhen518055 China

Integrated sensing and communication (ISAC) has been considered a key feature of next-generation wireless networks. This paper investigates the joint design of the radar receive filter and dual-functional transmit waveform for the multiple-input multiple-output (MIMO) ISAC system. While optimizing the mean square error (MSE) of the radar receive spatial response and maximizing the achievable rate at the communication receiver, besides the constraints of full-power radar receiving filter and unimodular transmit sequence, we control the maximum range sidelobe level, which is often overlooked in existing ISAC waveform design literature, for better radar imaging performance. To solve the formulated optimization problem with convex and nonconvex constraints, we propose an inexact augmented Lagrangian method (ALM) algorithm. For each subproblem in the proposed inexact ALM algorithm, we custom-design a block successive upper-bound minimization (BSUM) scheme with closed-form solutions for all blocks of variable to enhance the computational efficiency. Convergence analysis shows that the proposed algorithm is guaranteed to provide a stationary and feasible solution. Extensive simulations are performed to investigate the impact of different system parameters on communication and radar imaging performance. Comparison with the existing works shows the superiority of the proposed algorithm. © 2025, CC BY-NC-SA.

关键词： Mean square error

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