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A Potassium Atom Four-Level Active Optical Clock Scheme

Chinese Physics Letters 2013年第4期30卷 34-37页

作者： ZHANG Sheng-Nan WANG Yan-Fei ZHANG Tong-Gang ZHUANG Wei CHEN Jing-Biao Institute of Quantum Electronics and State Key Laboratory of Advanced Optical Communication and System Network School of Electronics Engineering and Computer SciencePeking UniversityBeijing 100871

We present an active optical clock scheme with a four-level quantum potassium *** calculate the population probabilities of each state using the density *** the steady state,ρ33 andρ55 are equal to 8.3%and 3.5%,respectively,and the population inversion between the 5S1/2 and 4P3/2 states is built up in the thermal potassium cell with a 404.7 nm pumping *** to the mechanism of the active optical clock,under the action of the 404.7 nm pumping laser,the scheme can output a 1252.2 nm quantum-limited-linewidth laser,which can be directly used as an active optical frequency standard.

关键词： pumping potassium quantum

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An Active Ion Optical Clock

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Chinese Physics Letters 2014年第9期31卷 48-51页

作者：庄伟张同刚陈景标 Institute of Quantum Electronics and State Key Laboratory of Advanced Optical Communication System and Network School of Electronics Engineering and Computer Science Peking University Beijing 100871

We propose a scheme for an active ion optical clock with a detailed description of the pumping method, lasing states, output power, linewidth and light shift. Considering 171 yb＋ ions in a Paul trap, we propose utilizing a Fabry-Perot resonator to realize the lasing of active optical frequency standards. The quantum-limited linewidth of an active 171 yb＋ ion optical clock is narrower than I mHz. Based on the mechanism and the advantages of an active optical clock at the ion optical clock transition frequency, this new laser light source as a stable local oscillator will be beneficial to the single-ion optical clock, which currently is one of the most accurate clocks.

关键词： ACTIVE medium FABRY-Perot resonators OPTICAL frequency conversion RESEARCH IONS QUANTUM mechanics

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Adiabatic Passage Based on the Calcium Active Optical Clock

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Chinese Physics Letters 2010年第7期27卷 105-107页

作者：解晓鹏庄伟陈景标 Institute of Quantum Electronics and State Key Laboratory of Advanced Optical Communication System & Network School of Electronics Engineering & Computer Science Peking University Beijing 100871

We propose a new application of the optical adiabatic passage effect for the excitation of a thermal atomic beam, which will be used in the calcium active optical clock to produce population inversion. A comparison between the optical adiabatic passage effect and the Rabi π pulse is investigated, 99% of the calcium atoms in the atomic beam that has a wide velocity distribution will be excited to the upper state for population inversion using the adiabatic passage, while 76% at most will be excited to the excited state using the π pulse with suitable parameters.

关键词： ATOMIC beams OPTICAL properties NUCLEAR excitation MATRIX inversion CALCIUM PARTICLE beams

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Error analysis and control of the acoustic overlapping mesh technique

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Applied Acoustics 2025年 238卷

作者： Wang, Youjiang Yang, Zhuangtao Liu, Zhenghao Ding, Yongle Zhang, Tao Zhang, Daiyu Yu, Long Key Laboratory of Marine Intelligent Equipment and System Ministry of Education Shanghai200240 China School of Ocean & Civil Engineering Shanghai Jiao Tong University Shanghai200240 China Kunming Branch of the 705 Research Institute China State Shipbuilding Corporation Limited Kunming China School of Marine Science and Technology Northwestern Polytechnical University Shaanxi Xi'an China Marine Design and Research Institute of China Shanghai China Xi'an Precision Machinery Research Institute Xi'an China School of Naval Architecture & Ocean Engineering Jiangsu University of Science and Technology Zhenjiang212003 China

Accurate and affordable methods for predicting the underwater radiated noise of ships will facilitate the development of effective noise control techniques. The acoustic overlapping mesh (AOM) technique, which enables the direct integration of volumetric noise terms in the Lighthill and FWH (Ffowcs Williams and Hawking) acoustic analogies, is a promising way to obtain such a method. In this paper, we improved the AOM technique by extending the overlapping mesh idea to the surface noise terms, further reducing the acoustic computational burden. Meanwhile, three causes for numerical errors of the AOM technique are identified and analyzed theoretically and numerically, leading to preliminary guidelines for choosing the acoustic mesh dimensions. The results suggest that keeping the cell-size-to-wavelength ratio (h/λ) lower than 0.05 avoids a sharp increase of the error from Cause-I, and keeping h/λ lower than 0.005 helps maintain this error less than 1 dB. The errors from the other causes (Cause-II and III) can be maintained less than 1 dB by keeping the distance-to-cell-size ratio (r/h) larger than 7.97. The simulation case also shows that the AOM technique reduces the acoustic computational time by more than 99% and 90% for the total and surface noise, respectively, while maintaining a noise prediction difference of around 1 dB. Using a non-uniform acoustic mesh instead of the uniform one helps achieve a much better with a similar acoustic computational time. © 2025 Elsevier Ltd

关键词： Numerical methods

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Mixed Structural Choice Operator: Enhancing Technology Mapping with Heterogeneous Representations

arXiv

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arXiv 2025年

作者： Hu, Zhang Pan, Hongyang Xia, Yinshui Wang, Lunyao Chu, Zhufei Faculty of Electrical Engineering and Computer Science Ningbo University Ningbo315211 China School of Microelectronics State Key Laboratory of Integrated Chips and System Fudan University Shanghai200433 China

—The independence of logic optimization and technology mapping poses a significant challenge in achieving high-quality synthesis results. Recent studies have improved optimization outcomes through collaborative optimization of multiple logic representations and have improved structural bias through structural choices. However, these methods still rely on technology-independent optimization and fail to truly resolve structural bias issues. This paper proposes a scalable and efficient framework based on Mixed Structural Choices (MCH). This is a novel heterogeneous mapping method that combines multiple logic representations with technology-aware optimization. MCH flexibly integrates different logic representations and stores candidates for various optimization strategies. By comprehensively evaluating the technology costs of these candidates, it enhances technology mapping and addresses structural bias issues in logic synthesis. Notably, the MCH-based lookup table (LUT) mapping algorithm set new records in the EPFL Best Results Challenge by combining the structural strengths of both And-Inverter Graph (AIG) and XOR-Majority Graph (XMG) logic representations. Additionally, MCH-based ASIC technology mapping achieves a 3.73% area and 8.94% delay reduction (balanced), 20.35% delay reduction (delay-oriented), and 21.02% area reduction (area-oriented), outperforming traditional structural choice methods. Furthermore, MCH-based logic optimization utilizes diverse structures to surpass local optima and achieve better results. Copyright © 2025, The Authors. All rights reserved.

关键词： Mapping

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Enhanced Privacy-Preserving WiFi Fingerprint Localization from CL Encryption

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Chinese Journal of Electronics 2024年第6期33卷 1435-1446页

作者： Zhiwei WANG Qiuchi ZHU Zhenqi ZHANG School of Computer Nanjing University of Posts and Telecommunications State Key Laboratory of Public Big Data Guizhou University Advanced Cryptography and System Security Key Laboratory of Sichuan Province Chengdu University of Information Engineering Key Laboratory of Computational Science and Application of Hainan Province Hainan Normal University

The WiFi fingerprint-based localization method is considered one of the most popular techniques for indoor localization. In INFOCOM'14, Li et al. proposed a wireless fidelity(WiFi) fingerprint localization system based on Paillier encryption, which is claimed to protect both client C 's location privacy and service provider S's database privacy. However, Yang et al. presented a practical data privacy attack in INFOCOM'18, which allows a polynomial time attacker to obtain S's database. We propose a novel WiFi fingerprint localization system based on CastagnosLaguillaumie(CL) encryption, which has a trustless setup and is efficient due to the excellent properties of CL encryption. To prevent Yang et al.'s attack, the system requires that S selects only the locations from its database that can receive the nonzero signals from all the available access points in C 's nonzero fingerprint in order to determine C's location. Security analysis shows that our scheme is secure under Li et al.'s threat model. Furthermore, to enhance the security level of privacy-preserving WiFi fingerprint localization scheme based on CL encryption, we propose a secure and efficient zero-knowledge proof protocol for the discrete logarithm relations in C's encrypted localization queries.

关键词： Location awareness Threat modeling Data privacy Protocols Databases Fingerprint recognition Trustless services Encryption Servers Wireless fidelity

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A Survey of Visual Analytic Pipelines

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Journal of computer Science & Technology 2016年第4期31卷 787-804页

作者： Xu-Meng Wang Tian-Ye Zhang Yu-Xin Ma Jing Xia Wei Chen State Key Laboratory of Computer Aided Design and Computer Graphics Zhejiang University Hangzhou 310058 China Innovation Joint Research Center for Cyber-Physical-Society System Zhejiang University Hangzhou 310058 China

Visual analytics has been widely studied in the past decade. One key to make visual analytics practical for both research and industrial applications is the appropriate definition and implementation of the visual analytics pipeline which provides effective abstractions for designing and implementing visual analytics systems. In this paper we review the previous work on visual analytics pipelines and individual modules from multiple perspectives： data, visualization, model and knowledge. In each module we discuss various representations and descriptions of pipelines inside the module, and compare the commonalities and the differences among them.

关键词： visual analytics pipeline visualization model knowledge

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Nash bargaining solution based multi-cell and multi-user interference alignment scheme for cellular networks

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The Journal of China Universities of Posts and Telecommunications 2014年第4期21卷 1-7,14页

作者： NIU Qin ZENG Zhi-min ZHANG Tian-kui GAO Qiu-bin SUN Shao-hui School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing Key Laboratory of Network System Architecture and Convergence Beijing University of Posts and Telecommunications State Key Laboratory of Wireless Mobile Communications China Academy of Telecommunication Technology

In wireless cellular networks, the interference alignment （IA） is a promising technique for interference management. A new IA scheme for downlink cellular network with multi-cell and multi-user was proposed, in the proposed scheme, the interference in the networks is divided into inter-cell interference （ICI） among cells and inter-user interference （IUI） in each cell. The ICI is aligned onto a multi-dimensional subspace by multiplying the ICI alignment precoding matrix which is designed by the singular value decomposition （SVD） scheme at the base station （BS） side. The aligned ICI is eliminated by timing the interference suppression matrix which is designed by zero-forcing （ZF） scheme at the user equipment （UE） side. Meanwhile, the IUI is aligned by multiplying the IUI alignment precoding matrix which is designed based on Nash bargaining solution （NBS） in game theory. The NBS is solved by the particle swarm optimization （PSO） method. Simulations show that, compared with the traditional ZF IA scheme, the proposed scheme can obtain higher data rate and guarantee the data rate fairness of UEs with little additional complexity.

关键词： cellular network interference alignment Nash bargaining solution data rate fairness particle swarm optimization

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Global evolution of an analyzer angle on the Faraday anomalous dispersion optical filter at 1529 nm

引用

Chinese Science Bulletin 2013年第36期58卷 4582-4587页

作者： TAO ZhiMing WANG YanFei HONG YeLong WANG DongYing ZHUANG Wei CHEN JingBiao State Key Laboratory of Advanced Optical Communication System and Network Institute of Quantum Electronics School of ElectronicsEngineering and Computer Science Peking University Department of Physics Bijie University

In order to realize laser frequency stabilization,the global evolution of an analyzer angle on the electrodeless-discharge-vaporlamp-based excited-state Faraday anomalous dispersion optical filter(LESFADOF)with a single transmission peak operating on the Rb1529 nm(5P3/2-4D5/2)is *** find that the transmission of the line center peak at 80°arrives at 14%in a 3 cm length lamp contained natural Rb mixed with 2 torr Xe buffer gas operating at 250°C with 176 MHz radio *** it is used to realize laser frequency stabilization,the LESFADOF at near 80°is *** a single transmission peak or double transmission peaks depend on the rf voltage when two polarizers are crossed.

关键词：法拉第反常色散光学滤波器演进激光稳频无电极放电无线电频率频率稳定激发态

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Multi-symplectic method for the generalized(2+1)-dimensionalKdV-mKdV equation

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Acta Mechanica Sinica 2012年第3期28卷 793-800页

作者： Wei-Peng Hu Zi-Chen Deng Yu-Yue Qin Wen-Rong Zhang School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnincal University710072 Xi'anChina State Key Laboratory of Mechanical System&Vibration Shanghai Jiao Tong University200240 ShanghaiChina State Key Laboratory of StructuralAnalysis of Industrial Equipment Dalian University of Technology116023 DalianChina

In the present paper, a general solution involv- ing three arbitrary functions for the generalized （2＋1）- dimensional KdV-mKdV equation, which is derived from the generalized （1＋1）-dimensional KdV-mKdV equa- tion, is first introduced by means of the Wiess, Tabor, Carnevale （WTC） truncation method. And then multi- symplectic formulations with several conservation laws taken into account are presented for the generalized （2＋1）- dimensional KdV-mKdV equation based on the multi- symplectic theory of Bridges. Subsequently, in order to simulate the periodic wave solutions in terms of rational functions of the Jacobi elliptic functions derived from thegeneral solution, a semi-implicit multi-symplectic scheme is constructed that is equivalent 1：o the Preissmann scheme. From the results of the numerical experiments, we can con- clude that the multi-symplectic schemes can accurately sim- ulate the periodic wave solutions of the generalized （2＋1）- dimensional KdV-mKdV equation while preserve approxi- mately the conservation laws.

关键词： Generalized （2＋ 1）-dimensional KdV-mKdVequation Multi-symplectic Periodic wave solution Con-servation law ~ Jacobi elliptic function

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