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Plasmonic Complex Fluids of Nematiclike and Helicoidal Self-Assemblies of Gold Nanorods with a Negative Order Parameter

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Physical Review Letters 2012年第8期109卷 088301-088301页

作者： Qingkun Liu Bohdan Senyuk Jianwei Tang Taewoo Lee Jun Qian Sailing He Ivan I. Smalyukh Department of Physics Material Science and Engineering Program Department of Electrical Computer & Energy Engineering and Liquid Crystal Materials Research Center University of Colorado Boulder Colorado 80309 USA Centre for Optical and Electromagnetic Research Zhejiang University Hangzhou 310058 People’s Republic of China Department of Electromagnetic Engineering Royal Institute of Technology S-100 44 Stockholm Sweden Renewable and Sustainable Energy Institute National Renewable Energy Laboratory and University of Colorado Boulder Colorado 80309 USA

We describe a soft matter system of self-organized oblate micelles and plasmonic gold nanorods that exhibit a negative orientational order parameter. Because of anisotropic surface anchoring interactions, colloidal gold nanorods tend to align perpendicular to the director describing the average orientation of normals to the discoidal micelles. Helicoidal structures of highly concentrated nanorods with a negative order parameter are realized by adding a chiral additive and are further controlled by means of confinement and mechanical stress. Polarization-sensitive absorption, scattering, and two-photon luminescence are used to characterize orientations and spatial distributions of nanorods. Self-alignment and effective-medium optical properties of these hybrid inorganic-organic complex fluids match predictions of a simple model based on anisotropic surface anchoring interactions of nanorods with the structured host medium.

关键词： PLASMONS (Physics) COMPLEX fluids MOLECULAR self-assembly GOLD nanoparticles PARAMETER estimation SOFT condensed matter

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Dynamic shortest path algorithms for hypergraphs

Dynamic shortest path algorithms for hypergraphs

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International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks (WiOpt)

作者： Jianhang Gao Qing Zhao Wei Ren Ananthram Swami Ram Ramanathan Amotz Bar-Noy Department of Electrical and Computer Engineering University of California Davis CA USA Microsoft Corporation Redmond WA USA Army Research Laboratory Adelphi MD USA Raytheon BBN Technologies Cambridge MA USA Department of Computer Science City University of New York NY USA

A hypergraph is a set V of vertices and a set of non-empty subsets of V , called hyperedges. Unlike graphs, hypergraphs can capture higher-order interactions in social and communication networks that go beyond a simple union of pairwise relationships. In this paper, we consider the shortest path problem in hypergraphs. We develop two algorithms for finding and maintaining the shortest hyperpaths in a dynamic network with both weight and topological changes. These two algorithms are the first to address the fully dynamic shortest path problem in a general hypergraph. They complement each other by partitioning the application space based on the nature of the change dynamics and the type of the hypergraph. We analyze the time complexity of the proposed algorithms and perform simulation experiments for both random geometric hypergraphs and the Enron email data set. The latter illustrates the application of the proposed algorithms in social networks for identifying the most important actor based on the closeness centrality metric.

关键词： Heuristic algorithms Social network services Shortest path problem Partitioning algorithms Complexity theory Electronic mail Color

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Break index labeling of mandarin text via syntactic-to-prosodic tree mapping

Break index labeling of mandarin text via syntactic-to-proso...

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International Symposium on Chinese Spoken Language Processing

作者： Xiaotian Zhang Yao Qian Hai Zhao Frank K. Soong Center for Brain-Like Computing and Machine Intelligence Department of Computer Science and Engineering MOE-Microsoft Key Laboratory for Intelligent Computing and Intelligent Systems Shanghai Jiaotong University Shanghai China Microsoft Research Asia Beijing China

In this study, we investigate the break index labeling problem with a syntactic-to-prosodic structure conversion. The statistical relationship between the mapped syntactic tree structure and prosodic tree structure of sentences in the training set is used to generate a Synchronous Tree Substitution Grammar (STSG) which can describe the probabilistic mapping (substitution) rules between them. For a given test sentence and the corresponding parsed syntactic tree structure, thus generated STSG can convert the syntactic tree to a prosodic tree statistically. We compare the labeling results with other approaches and show the probabilistic mapping can indeed benefit break index labeling performance.

关键词： IP networks Biological system modeling Pragmatics Abstracts Syntactics

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Towards an Ontology for Autonomous Robots

Towards an Ontology for Autonomous Robots

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2012 IEEE/RSJ International Conference on Intelligent Robots and systems

作者： Liam Paull Gaetan Severac Guilherme V. Raffo Julian Mauricio Angel Harold Boley Phillip J Durst Wendell Gray Maki Habib Bao Nguyen S. Veera Ragavan Sajad Saeedi G. Ricardo Sanz Mae Seto Aleksandar Stefanovski Michael Trentini Howard Li COBRA Department of Electrical and Computer Engineering University of New Brunswick Fredericton Canada ONERA - University of Toulouse France Department of Automation and Systems Federal University of Santa Catarina Brazil Department of Computer Engineering Pontificia Universidad Javeriana Bogot Colombia National Research Council Canada US Army ERDC Vicksburg Ms Mechanical Engineering Department School of Sciences and Engineering The American University in Cairo New Cairo Egypt Defence Research and Development Canada - CORA Ottawa ON Canada Monash University Sunway Campus Systems Engineering and Automatic Control Autonomous Systems Laboratory research group Universidad Politcnica de Madrid Madrid Spain Defence Research and Development Canada - Atlantic NS Canada Department of Computer Science The George Washington University Defence R&D Canada - Suffield Medicine Hat AB Canada

ISBN: (纸本)9781467317375

The IEEE RAS Ontologies for Robotics and Automation Working Group is dedicated to developing a methodology for knowledge representation and reasoning in robotics and automation. As part of this working group, the Autonomous Robots sub-group is tasked with developing ontology modules for autonomous robots. This paper describes the work in progress on the development of ontologies for autonomous systems. For autonomous systems, the focus is on the cooperation, coordination, and communication of multiple unmanned aerial vehicles (UAVs), unmanned ground vehicles (UGVs), and autonomous underwater vehicles (AUVs). The ontologies serve as a framework for working out concepts of employment with multiple vehicles for a variety of operational scenarios with emphasis on collaborative and cooperative missions.

关键词： Ontologies Robot kinematics Sensors Planning Mobile robots Navigation

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Handwritten and Machine Printed Text Separation in Document Images Using the Bag of Visual Words Paradigm

Handwritten and Machine Printed Text Separation in Document ...

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International Workshop on Frontiers in Handwriting Recognition

作者： Konstantinos Zagoris Ioannis Pratikakis Apostolos Antonacopoulos Basilis Gatos Nikos Papamarkos Pattern Recognition and Image Analysis (PRImA) Research Laboratory School of Computing Science and Engineering University of Salford Greater Manchester UK Department of Electrical and Computer Engineering Democritus University of Thrace Xanthi Greece Institute of Informatics and Telecommunications National Center for Scientific Research Demokritos Athens Greece

In a number of types of documents, ranging from forms to archive documents and books with annotations, machine printed and handwritten text may be present in the same document image, giving rise to significant issues within a digitisation and recognition pipeline. It is therefore necessary to separate the two types of text before applying different recognition methodologies to each. In this paper, a new approach is proposed which strives towards identifying and separating handwritten from machine printed text using the Bag of Visual Words paradigm (BoVW). Initially, blocks of interest are detected in the document image. For each block, a descriptor is calculated based on the BoVW. The final characterization of the blocks as Handwritten, Machine Printed or Noise is made by a Support Vector Machine classifier. The promising performance of the proposed approach is shown by using a consistent evaluation methodology which couples meaningful measures along with a new dataset.

关键词： Visualization Noise Image segmentation Hidden Markov models Gabor filters Handwriting recognition Text recognition

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Live assessment of beat tracking for robot audition

Live assessment of beat tracking for robot audition

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2012 IEEE/RSJ International Conference on Intelligent Robots and systems

作者： João Lobato Oliveira Gökhan Ince Keisuke Nakamura Kazuhiro Nakadai Hiroshi G. Okuno Luis Paulo Reis Fabien Gouyon Institute for Systems and Computer Engineering of Science and Technology (INESC TEC) Porto Portugal Department of Intelligence Science and Technology Graduate School of Informatics Kyoto University Kyoto Japan Honda Research Institute Japan Company Limited Saitama Japan Artificial Intelligence and Computer Science Laboratory (LIACC) FEUP Porto Portugal School of Engineering-DSI University of Minho Guimaraes Portugal

In this paper we propose the integration of an online audio beat tracking system into the general framework of robot audition, to enable its application in musically-interactive robotic scenarios. To this purpose, we introduced a staterecovery mechanism into our beat tracking algorithm, for handling continuous musical stimuli, and applied different multi-channel preprocessing algorithms (e.g., beamforming, ego noise suppression) to enhance noisy auditory signals lively captured in a real environment. We assessed and compared the robustness of our audio beat tracker through a set of experimental setups, under different live acoustic conditions of incremental complexity. These included the presence of continuous musical stimuli, built of a set of concatenated musical pieces; the presence of noises of different natures (e.g., robot motion, speech); and the simultaneous processing of different audio sources on-the-fly, for music and speech. We successfully tackled all these challenging acoustic conditions and improved the beat tracking accuracy and reaction time to music transitions while simultaneously achieving robust automatic speech recognition.

关键词： Noise Robots Speech Tracking Speech processing Accuracy Acoustics

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Conjugate Fabry-Perot cavity pair for astro-combs

Conjugate Fabry-Perot cavity pair for astro-combs

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Conference on Lasers and Electro-Optics (CLEO)

作者： Chih-Hao Li Guoqing Chang Alexander Glenday David F. Phillips Franz X. Kärtner Ronald L. Walsworth Harvard-Smithsonian Center for Astrophysics Harvard University Cambridge MA USA Department of Electrical Engineering and Computer Science and Research Laboratory of Electronics Massachusetts Institute of Technology Cambridge MA USA Center for Free-Electron Laser Science DESY and Department of Physics University of Hamburg Hamburg Germany

We propose a new mode-filtering scheme for astro-combs using two Fabry-Perot cavities: a “conjugate Fabry-Perot cavity pair”. Simulations suggest that this scheme improves astro-comb accuracy in the presence of erro... 详细信息

ISBN: (纸本)9781557529435

关键词： Cavity resonators Accuracy Systematics Laser modes Fabry-Perot Degradation Optimized production technology

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Quantum M-ary phase shift keying

Quantum M-ary phase shift keying

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IEEE International Symposium on Information Theory

作者： Ranjith Nair Brent J. Yen Saikat Guha Jeffrey H. Shapiro Stefano Pirandola Department of Electrical & Computer Engineering National University of Singapore Singapore Disruptive Information Processing Technologies Group Raytheon BBN Technologies Cambridge Massachusetts USA Research Laboratory of Electronics Massachusetts Institute of Technology Cambridge Massachusetts USA Department of Computer Science University of York York United Kingdom

We develop a theory of quantum M-ary phase shift keying in which quantum states of optical modes are modulated at the transmitter by applying one of M uniformly-spaced phase shifts. We allow full freedom in choosing modulation states with any number of signal, i.e., transmitted, and ancilla modes, subject only to an average energy, i.e., photon number, constraint in either the signal modes alone or in the signal and ancilla modes together. For lossless operation and unrestricted POVM measurements at the receiver, we find the explicit form of the modulation state that minimizes the average error probability under an energy constraint of N photons. Multiple signal modes, mixed states, and entanglement with an ancilla are shown to be unnecessary for optimum performance. We show that communication with zero error is possible if and only if N ≥ (M - 1)/2.

关键词： Optical transmitters Error probability Phase shift keying Photonics Quantum mechanics

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Utilizing RFID-WSNs for reducing the footprint of the Oil Sands industry

Utilizing RFID-WSNs for reducing the footprint of the Oil Sa...

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IEEE Globecom Workshops

作者： Ashraf Al-Fagih Ahmad El Kouche Sharief Oteafy Abdallah Alma'aitah Telecommunications Research Laboratory School of Computing Queens University Kingston ONT Canada Information and Computer Science Department King Fahd University of Petroleum and Minerals Dhahran Saudi Arabia Telecommunications Research Lab School of Computing Kingston Ontario Canada Department of Electrical and Computer Engineering Queen's University Kingston Ontario Canada

In harsh operational conditions, machines lose components on a frequent basis, causing a significant footprint to the surrounding environment. This affects operational up-time, safety measures and cost effectiveness. This paper proposes the use of an integrated RFID-WSN architecture to reduce the footprint of mining equipment used in the Canadian Oil Sands industry. Sensors and RFID tags provide both identification and positioning data for detecting broken parts from Ground Engaging Tools (GETs), such as huge shovel teeth. A delay-tolerant delivery approach utilizes mobile couriers, placed on loading trucks available in the vicinity, to store and carry data from readers and relays to remote base-stations. Delivering data in such harsh mining environments poses several challenges including power scarcity, vast transmission distances and the lack of an accessible communication infrastructure. We provide a use case to demonstrate how this architecture successfully overcomes these challenges within the harsh industrial environment of the Oil Sands.

关键词： Temperature sensors Radiofrequency identification Temperature measurement Hydrocarbons Monitoring Vibrations

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A study of parallelizing O(N) Green-function-based Monte Carlo method for many fermions coupled with classical degrees of freedom

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Journal of Physics: Conference Series 2013年第1期454卷

作者： Shixun Zhang Shinichi Yamagia Seiji Yunoki Department of Computer Science University of Tsukuba Tsukuba Ibaraki 305-8573 Japan Faculty of Engineering Information and Systems University of Tsukuba / JST PRESTO 1-1-1 Tennodai Tsukuba Ibaraki 305-8573 Japan Computational Condensed Matter Physics Laboratory RIKEN ASI Wako Saitama 351-0198 Japan Computational Materials Science Research Team RIKEN AICS Kobe Hyogo 650-0047 Japan CREST Japan Science and Technology Agency Kawaguchi Saitama 332-0012 Japan

Models of fermions interacting with classical degrees of freedom are applied to a large variety of systems in condensed matter physics. For this class of models, Weiße [Phys. Rev. Lett. 102, 150604 (2009)] has recently proposed a very efficient numerical method, called O(N) Green-Function-Based Monte Carlo (GFMC) method, where a kernel polynomial expansion technique is used to avoid the full numerical diagonalization of the fermion Hamiltonian matrix of size N, which usually costs O(N3) computational complexity. Motivated by this background, in this paper we apply the GFMC method to the double exchange model in three spatial dimensions. We mainly focus on the implementation of GFMC method using both MPI on a CPU-based cluster and Nvidia's Compute Unified Device Architecture (CUDA) programming techniques on a GPU-based (Graphics Processing Unit based) cluster. The time complexity of the algorithm and the parallel implementation details on the clusters are discussed. We also show the performance scaling for increasing Hamiltonian matrix size and increasing number of nodes, respectively. The performance evaluation indicates that for a 323 Hamiltonian a single GPU shows higher performance equivalent to more than 30 CPU cores parallelized using MPI.

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