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Atomic layer reversal on CeO_2 (100) surface

Science China Materials 2017年第9期60卷 903-908页

作者：黄静露余运波朱静于荣 National Center for Electron Microscopy in Beijing Key Laboratory of Advanced Materials of Ministry of Education of China and State KeyLaboratory of New Ceramics and Fine ProcessingSchool of Materials Science and EngineeringTsinghua UniversityBeijing 100084China State Key Joint Laboratory of Environment Simulation and Pollution Control Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Center for Excellence in Regional Atmospheric Environment Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China University of Chinese Academy of Sciences Beijing 100049China

The structure and properties of CeO2 surfaces have been intensively studied due to their importance in a lot of surface-related applications. Since most of surface techniques probe the structure information inside the outermost surface plane, the subsurface structure information has been elusive in many studies. Using the profile imaging with aberration-corrected transmission electron microscopy, the structure information in both the outermost layer and the sublayers of the CeO2（100） surface has been obtained. In addition to the normal structures that have been reported before, where the surface is Ce-or O-terminated, a metastable surface has been discovered. In the new structure, there is an atomic layer reversal between the outermost layer and the sublayer, giving a structure with O as the outermost layer for the stoichiometry of normal Ce-terminated surface. The charge redistribution for the polarity compensation has also been changed relative to the normal surface.

关键词： surface structure ceria atomic layer reversal aberration-corrected TEM first-principles calculations

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Design of a nonlinear adaptive natural oscillator: Towards natural dynamics exploitation in cyclic tasks

Design of a nonlinear adaptive natural oscillator: Towards n...

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IEEE/RSJ International Conference on intelligent Robots and systems

作者： Rezvan Nasiri Mahdi Khoramshahi Majid Nili Ahmadabadi Cognitive Robotics Laboratory Control and Intelligent Processing Center of Excellence (CIPCE) School of Electrical and Computer Engineering College of Engineering University of Tehran Iran

ISBN: (纸本)9781509037636

In this paper, we present the dynamical equations of a nonlinear adaptive natural oscillator (NANO) in order to exploit the natural dynamics in robotic systems. The presented oscillator tries to minimize an energy-based cost function by adapting the shape and frequency of the reference trajectory. Stability, convergence, and optimality of this oscillator are guaranteed analytically. Moreover, the performance of this oscillator is investigated by applying it to three different types of robotic models;i.e., the pendulum, the adaptive-toy, and the hopper-leg.

关键词： Trajectory Learning Energy Efficiency Cyclic Tasks Natural Dynamics

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Design and modeling of a compact rotational nonlinear spring

Design and modeling of a compact rotational nonlinear spring

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IEEE/RSJ International Conference on intelligent Robots and systems

作者： Hamed Jalaly Bidgoly Majid Nili Ahmadabadi Mohammad Reza Zakerzadeh Cognitive Robotics Laboratory The Control and Intelligent Processing Center of Excellence (CIPCE) School of Electrical and Computer Engineering College of Engineering University of Tehran Iran Dynamic and Vibration Laboratory School of Mechanical Engineering College of Engineering University of Tehran Iran

ISBN: (纸本)9781509037636

In this paper, we propose a new method for implementing a rotational nonlinear spring with user defined profile, based on the combination of a linear spring with a nonlinear transmission mechanism. The proposed structure consists of a non-circular cam, a roller which moves along outer circumference of the cam, and a stretched translational linear spring which is connected between center of the cam and center of the roller. We obtain a set of differential equations to design shape of the cam for any given torque-angle profile. Also, it will be shown that profiles with both positive and negative values can be implemented by the proposed method. At last, the cam of some popular nonlinear springs are designed, including constant, cubic, hyperbolic tangent and sinusoidal springs.

关键词： Computer aided manufacturing Camelopardalis Hookean spring springs Device Spring TRANSFER MECHANISM Modeling nonlinearity Rotational SCROLL Differential equations Spring season

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Robust Vehicle Localization with GPS Dropouts

Robust Vehicle Localization with GPS Dropouts

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International Conference on intelligent and advanced systems

作者： Salman Ali Shaukat Muhammad Arif Umar Iqbal Bhatti Khalid Munawar Aamer Iqbal Bhatti Ubaid M. Al-Saggaf Center of Excellence in Intelligent Engineering Systems King Abdulaziz University Department of Computer Science Umm-Alqura University Department of Aeronautics and Astronautics Institute of Space Technology Control and Signal Processing Research Group Capital University of Science and Technology

ISBN: (纸本)9781509008469

Vehicle navigation systems rely on the correct positioning information and GPS is the best solution. However, in situations of GPS outage, like in tunnels and dense woods, the vehicle can lose track quickly. Modern vehicle navigation systems are mostly based on the vehicle dynamics;proprietary algorithms keep navigating for quite some time. But these solutions are expensive and add much to a vehicle's cost. This paper proposes a Kalman filter based dead-reckoning algorithm that fuses GPS information with the orientation information from a cheap IMU/INS, and the vehicle's speed accessed from its ECU. This low-cost system uses GPS and IMU/INS in a loosely coupled manner along with vehicle's speed and keeps supplying a quite accurate position information with GPS outage for significantly long intervals. With proper tuning and initialization, the proposed scheme has a potential to keep working in a completely GPS-denied situation.

关键词： Navigation GPS IMU/INS Dead-reckoning

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Possible structural origin of superconductivity in Sr-doped Bi2Se3

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Physical Review Materials 2018年第1期2卷 014201-014201页

作者： Zhuojun Li Meng Wang Dejiong Zhang Nan Feng Wenxiang Jiang Chaoqun Han Weijiong Chen Mao Ye Chunlei Gao Jinfeng Jia Jixue Li Shan Qiao Dong Qian Ben Xu He Tian Bo Gao CAS Center for Excellence in Superconducting Electronics (CENSE) Shanghai 200050 China State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences 865 Changning Road Shanghai 200050 China University of Chinese Academy of Sciences Beijing 100049 China Center of Electron Microscopy and State Key Laboratory of Silicon Materials School of Materials Science and Engineering Zhejiang University Hangzhou 310027 China State Key Laboratory of New Ceramics and Fine Processing Department of Materials Science and Engineering Tsinghua University Beijing 100084 People's Republic of China Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education) School of Physics and Astronomy Shanghai Jiao Tong University Shanghai 200240 China State Key Laboratory of Surface Physics and Department of Physics Fudan University Shanghai 200433 China Collaborative Innovation Center of Advanced Microstructures Nanjing 210093 China

Doping bismuth selenide (Bi2Se3) with elements such as copper and strontium (Sr) can induce superconductivity, making the doped materials interesting candidates to explore potential topological superconducting behaviors. It was thought that the superconductivity of doped Bi2Se3 was induced by dopant atoms intercalated in van der Waals gaps. However, several experiments have shown that the intercalation of dopant atoms may not necessarily make doped Bi2Se3 superconducting. Thus, the structural origin of superconductivity in doped Bi2Se3 remains an open question. Herein, we combined material synthesis and characterization, high-resolution transmission electron microscopy, and first-principles calculations to study the doping structure of Sr-doped Bi2Se3. We found that the emergence of superconductivity is strongly related with n-type dopant atoms. Atomic-level energy-dispersive x-ray mapping revealed various n-type Sr dopants that occupy intercalated and interstitial positions. First-principles calculations showed that the formation energy of a specific interstitial Sr doping position depends strongly on the Sr doping level. This site changes from a metastable position at low Sr doping level to a stable position at high Sr doping level. The calculation results explain why quenching is necessary to obtain superconducting samples when the Sr doping level is low and also why slow furnace cooling can yield superconducting samples when the Sr doping level is high. Our findings suggest that Sr atoms doped at interstitial locations, instead of those intercalated in van der Waals gaps, are most likely to be responsible for the emergence of superconductivity in Sr-doped Bi2Se3.

关键词： Dopants Impurities in superconductors

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The Analysis and Simulation of a Tethered Segway

The Analysis and Simulation of a Tethered Segway

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RSI/ISM International Conference on Robotics and Mechatronics

作者： Mohammad Hossein Salehpour Hadi Moradi Control and Intelligent Processing Center of Excellence School of Electrical Engineering University of Tehran Tehran Iran Control and Intelligent Processing Center of Excellence School of Electrical Engineering University of Tehran Tehran Iran Intelligent Systems Research Institute SKKU South Korea

ISBN: (纸本)9781467372350

In this paper we present the design and analysis of a tethered Segway designed for moving over steep surfaces such as dome shaped structures. This robotic platform, inspired from human climbers who use a cable to keep themselves stable on steep surfaces, consists of a simple Segway and a mechanism used to tether the robot to the top of the surface. The mathematical model of the robot is derived using Lagrangian approach and the control is developed based on a state feedback gain. The model consists of a two wheeled inverted pendulum driven by two DC motors. Also there is a DC motor used to control the length of the cable tethering the robot to the top. The control inputs are the voltages applied to each DC motor. The system has been simulated and the results show that the controller can move the robot around while keeping its stability on steep surfaces up to 75 degrees.

关键词： tethered robot robotic platform stabilization model of Segway Lagrangian approach state feedback

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Counterattack detection in broadcast soccer videos using camera motion estimation

Counterattack detection in broadcast soccer videos using cam...

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2015 International Symposium on Artificial Intelligence and Signal processing, AISP 2015

作者： Sigari, Mohamad-Hoseyn Soltanian-Zadeh, Hamid Kiani, Vahid Pourreza, Amid-Reza Control and Intelligent Processing Center of Excellence School of Electrical and Computer Engineering College of Engineering University of Tehran Tehran Iran Machine Vision Research Laboratory Computer Engineering Department Faculty of Engineering Ferdowsi University of Mashhad Mashhad Iran

ISBN: (纸本)9781479988174

This paper presents a new method for counterattack detection using estimated camera motion and evaluates some classification methods to detect this event. To this end, video is partitioned to shots and view type of each shot is recognized first. Then, relative pan of the camera during far-view and medium-view shots is estimated. After weighting of pan value of each frame according to the type of shots, the video is partitioned to motion segments. Then, motion segments are refined to achieve better results. Finally, the features extracted from consecutive motion segments are investigated for counterattack detection. We propose two methods for counterattack detection: (1) rule-based (heuristic rules) and (2) SVM-based. Experiments show that the SVM classifier with linear or RBF kernel results in the best results. © 2015 IEEE.

关键词： Motion estimation

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DESYNCHRONIZATION OF TWO COUPLED LIMIT-CYCLE OSCILLATORS USING AN ASTROCYTE-INSPIRED controlLER

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International Journal of Biomathematics 2014年第1期7卷 1-23页

作者： GHAZAL MONTASERI MOHAMMAD JAVAD YAZDANPANAH Advanced Control Systems Laboratory School of Electrical and Computer EngineeringCollege of Engineering University of Tehran Tehran Iran Advanced Control Systems LaboratoryControl and Intelligent Processing Center of Excellence School of Electrical and Computer Engineering College of Engineering University of Tehran Tehran Iran

Astrocytes have potential to break synchrony between neurons. Authors＇ recent researches reveal that astrocytes vary the synchronization threshold and provide an appropriate feedback control in stabilizing neural activities. In this study, we propose an astrocyte-inspired controller for desynchronization of two coupled limit-cycle oscillators as a minimal network model. The design procedure consists of two parts. First, based on the astrocyte model, the structure of the dynamic controller is suggested. Then, to have an emcient controller, parameters of controller are tuned through an optimization algo- rithm. The proposed bio-inspired controller takes advantages of three important proper- ties：（1） the controller desynchronizes the oscillators without any undesirable effects （e.g. stopping, annihilating or starting divergent oscillations）; （2） it consumes little effort to preserve the desirable desynchronized state; and （3） the controller is robust with respect to parameters＇ variations. Simulation results reveal the ability of the proposed controller.

关键词： Astrocyte dynamic model bio-inspired controller coupled limit-cycle oscillators desynchronization optimization

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Toward Aerial Simultaneous Target Localization and Obstacle Estimation using RSSI observations

Toward Aerial Simultaneous Target Localization and Obstacle ...

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RSI/ISM International Conference on Robotics and Mechatronics

作者： S.M. Mehdi Dehghan Saeid Haidari Hadi Mordi Control and Intelligent Processing Center of Excellence School of ECE University of Tehran Malek Ashtar University of Technology Aerospace Research Complexity Tehran Iran Advaced Robotic and Intelligent System Lab School of ECE University of Tehran Tehran Iran Control and Intelligent Processing Center of Excellence School of ECE University of Tehran Tehran Iran Intelligent Systems Research Institute SKKU South Korea

ISBN: (纸本)9781467372350

This paper represents simultaneous estimation of an RF source location and the location and height of an obstacle between the RF source and a UAV using RSSI observations. The aim is to improve the localization of the RF source by estimating the location and height of the obstacle. The effect of the obstacle on signal strength attenuation, i.e. the diffraction loss, is the most important reason that affects the performance of distance estimation based on general or empirical path loss model. Consequently, by estimating the effect of obstacle on attenuation, it will be possible to improve the accuracy of distance estimation according to path loss models. The simultaneous estimation of radio source location and the specification of an existing obstacle are implemented using particle filter, due to the complexity and nonlinear nature of the equations related to the calculation of diffraction loss. The simulation results show an improved performance of suggested filter, compared to the basic case of not estimating the obstacle.

关键词： UA V RF source localization NLOS obstacle mapping signal diffraction

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Cover Feature: Ultrasensitive, Sustainable, and Selective Electrochemical Hydrazine Detection by ALD-Developed Two-Dimensional WO3(ChemElectroChem 2/2018)

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ChemElectroChem 2017年第2期5卷

作者： Zihan Wei Zhenyin Hai Mohammad Karbalaei Akbari Prof. Jie Hu Lachlan Hyde Prof. Stephen Depuydt Prof. Francis Verpoort Prof. Serge Zhuiykov Ghent University Global Campus Department of Applied Analytical & Physical Chemistry 119 Songdomunhwa-ro Yeonsu-gu Incheon South Korea Micro and Nano System Research Center Key Lab of Advanced Transducers and Intelligent Control System (Ministry of Education) & College of Information Engineering Taiyuan University of Technology Taiyuan 030024 Shanxi PR China Factory of the Future Swinburne University of Technology Hawthorn Australia National Research Tomsk Polytechnic University Lenin Avenue 30 634050 Tomsk Russian Federation Laboratory of Organometallics Catalysis and Ordered Materials State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Center for Chemical and Material Engineering Wuhan University of Technology Wuhan P.R. China

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