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Is More Better? — Night Vision Enhancement System’s Pedestrian Warning Modes and Older Drivers

Brown, Timothy; He, Yefei; Roe, Cheryl; Schnell, Thomas
Fonte: Association for the Advancement of Automotive Medicine Publicador: Association for the Advancement of Automotive Medicine
Tipo: Artigo de Revista Científica
Publicado em /01/2010 Português
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Pedestrian fatalities as a result of vehicle collisions are much more likely to happen at night than during day time. Poor visibility due to darkness is believed to be one of the causes for the higher vehicle collision rate at night. Existing studies have shown that night vision enhancement systems (NVES) may improve recognition distance, but may increase drivers’ workload. The use of automatic warnings (AW) may help minimize workload, improve performance, and increase safety. In this study, we used a driving simulator to examine performance differences of a NVES with six different configurations of warning cues, including: visual, auditory, tactile, auditory and visual, tactile and visual, and no warning. Older drivers between the ages of 65 and 74 participated in the study. An analysis based on the distance to pedestrian threat at the onset of braking response revealed that tactile and auditory warnings performed the best, while visual warnings performed the worst. When tactile or auditory warnings were presented in combination with visual warning, their effectiveness decreased. This result demonstrated that, contrary to general sense regarding warning systems, multi-modal warnings involving visual cues degraded the effectiveness of NVES for older drivers.

Implementation of a human avatar for the MARG project in networked virtual environments

Yildiz, Faruk
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado
Português
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Approved for public release; distribution is unlimited.; The objective of the ongoing MARG project is to animate human motions captured by 15 MARG sensors in wireless networked virtual environment (NVES). Three avatars were developed previously, but none of them met all the desired requirements. The first one was overly simplistic and did not implement H-Anim standards. The other two were created using laser-scanned data and followed the H-Anim standards, but one had its adjacent joints broken and the other was capable of rotating only one joint. Therefore, the cartoon-type humanoid, Andy, was developed to meet the needs of the MARG project. The humanoid Andy implements H-Anim standards using built-in X3D humanoid nodes and is capable of controlling all its 15 joints in NVES. Another need of the MARG project was a wireless network interface for real-time data streaming. A concurrent client-server program implementing multicasting using TCP and UDP protocols was developed for this purpose. Using WiSER2400.IP serial adapters between the MARG sensors and the server program adds a wireless capability to the project. The server program converts the raw MARG sensor data to quaternions using the Quest algorithm. Multiple clients are supported by the system. Each client program receives the motion data and updates the humanoid Andy.

WebSockets for NVEs

McGregor, Don
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Conferência ou Objeto de Conferência
Português
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MOVES Research & Education Systems Seminar: Presentation; Session 2: Influencing M&S Policy and Standards; Influencing M&S Standards Development – Part 2: Open-DIS using Web Standards; speakers: Don Brutzman & Don McGregor

X3D Distributed Interactive Simulation (DIS) Implementation and Run-Time Discovery of New Entities using X3DOM

McGregor, Don; Harder, Byron; Brutzman, Don
Fonte: Escola de Pós-Graduação Naval Publicador: Escola de Pós-Graduação Naval
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
27.67287%
New capabilities in web browser JavaScript implementations including networking, improved graphics performance, and improved speed allow the implementation of Networked Virtual Environments (NVEs) inside the web browser. An NVE can be written in JavaScript, which enables deployment in the enterprise entirely from a web server without the use of browser plugins. We discuss one implementation of this idea using X3DOM, an opensource implementation of the X3D standard written in JavaScript. The Open-DIS library for the IEEE Distributed Interactive Simulation (DIS) network protocol is used to create a partial implementation of the X3D standard’s DIS profile. Mechanisms for using the X3D DIS Profile DISEntityTypeMapping and DISEntityManager to enable run-time discovery and launching of new entities are discussed. Measurements of the capabilities and performance aspects of Websockets for network transport demonstrate excellent results.

One-step generation of multipartite entanglement among nitrogen-vacancy center ensembles

Song, Wan-lu; Yin, Zhang-qi; Yang, Wan-li; Zhu, Xiao-bo; Zhou, Fei; Feng, Mang
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
Publicado em 13/01/2015 Português
Relevância na Pesquisa
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We describe a one-step, deterministic and scalable scheme for creating macroscopic arbitrary entangled coherent states (ECSs) of separate nitrogen-vacancy center ensembles (NVEs) that couple to a superconducting flux qubit. We discuss how to generate the entangled states between the flux qubit and two NVEs by the resonant driving. Then the ECSs of the NVEs can be obtained by projecting the flux qubit, and the entanglement detection can be realized by transferring the quantum state from the NVEs to the flux qubit. Our numerical simulation shows that even under current experimental parameters the concurrence of the ECSs can approach unity. We emphasize that this method is straightforwardly extendable to the case of many NVEs.

Enforcing Semantic Integrity on Untrusted Clients in Networked Virtual Environments

Hermann, Uwe; Katzenbeisser, Stefan; Schallhart, Christian; Veith, Helmut
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 29/03/2005 Português
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During the last years, large-scale simulations of realistic physical environments which support the interaction of multiple participants over the Internet have become increasingly available and economically significant, most notably in the computer gaming industry. Such systems, commonly called networked virtual environments (NVEs), are usually based on a client-server architecture where for performance reasons and bandwidth restrictions, the simulation is partially deferred to the clients. This inevitable architectural choice renders the simulation vulnerable to attacks against the semantic integrity of the simulation: malicious clients may attempt to compromise the physical and logical laws governing the simulation, or to alter the causality of events a posteriori. In this paper, we initiate the systematic study of semantic integrity in NVEs from a security point of view. We argue that naive policies to enforce semantic integrity involve intolerable network load, and are therefore not practically feasible. We present a new semantic integrity protocol based on cryptographic primitives which enables the server system to audit the local computations of the clients on demand. Our approach facilitates low network and CPU load, incurs reasonable engineering overhead...

Quantum information processing on nitrogen-vacancy ensembles with the local resonance assisted by circuit QED

Tao, Ming-Jie; Hua, Ming; Ai, Qing; Deng, Fu-Guo
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 09/03/2015 Português
Relevância na Pesquisa
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With the local resonant interaction between a nitrogen-vacancy-center ensemble (NVE) and a superconducting coplanar resonator, and the single-qubit operation, we propose two protocols for the state transfer between two remote NVEs and for fast controlled-phase (c-phase) on these NVEs, respectively. This hybrid quantum system is composed of two distant NVEs coupled to separated high-Q transmission line resonators (TLRs), which are interconnected by a current-biased Josephsonjunction superconducting phase qubit. The fidelity of our state-transfer protocol is about 99.65% within the operation time of 70.60 ns. The fidelity of our c-phase gate is about 98.23% within the operation time of 93.87 ns. Furthermore, using the c-phase gate, we construct a two-dimensional cluster state on NVEs in n*n square grid based on the hybrid quantum system for the one-way quantum computation. Our protocol may be more robust, compared with the one based on the superconducting resonators, due to the long coherence time of NVEs at room temperature.; Comment: 10 pages, 4 figures

High-fidelity quantum memory using nitrogen-vacancy center ensemble for hybrid quantum computation

Yang, W. L.; Yin, Zhang-qi; Hu, Y.; Feng, M.; Du, J. F.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 15/06/2011 Português
Relevância na Pesquisa
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We study a hybrid quantum computing system using nitrogen-vacancy center ensemble (NVE) as quantum memory, current-biased Josephson junction (CBJJ) superconducting qubit fabricated in a transmission line resonator (TLR) as quantum computing processor and the microwave photons in TLR as quantum data bus. The storage process is seriously treated by considering all kinds of decoherence mechanisms. Such a hybrid quantum device can also be used to create multi-qubit W states of NVEs through a common CBJJ. The experimental feasibility and challenge are justified using currently available technology.; Comment: 4 pages, 4 figures, accepted for PRA rapid communication

Generating a macroscopic entangled coherent state of quantum memories in circuit QED

Liu, Tong; Su, Qi-Ping; Xiong, Shao-Jie; Liu, Jin-Ming; Yang, Chui-Ping; Nori, Franco
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
17.672871%
$W$-type entangled states can be used as quantum channels for, e.g., quantum teleportation, quantum dense coding, and quantum key distribution. In this work, we propose a way to generate a macroscopic $W$-type entangled coherent state using quantum memories in circuit QED. The memories considered here are nitrogen-vacancy center ensembles (NVEs), each located in a different cavity. This proposal does not require initially preparing each NVE in a coherent state instead of a ground state, which should significantly reduce its experimental difficulty. For most of the operation time, each cavity remains in a vacuum state, thus decoherence caused by the cavity decay and the unwanted inter-cavity crosstalk are greatly suppressed. Moreover, only one external-cavity coupler qubit is needed. The prepared $W$ state can be stored via NVEs for a long time, mapped onto cavities, and then transferred into a quantum network via optical fibers, each linked to a cavity, for potential applications in quantum communication. This method is quite general and can be applied to generate the proposed $W$ state with atomic ensembles or other spin ensembles distributed in different cavities.; Comment: 15 pages, 6 figures

Quantum simulation of artificial Abelian gauge field using nitrogen-vacancy center ensembles coupled to superconducting resonators

Yang, W. L.; Yin, Zhang-qi; Chen, Z. X.; Kou, Su-Peng; Feng, M.; Oh, C. H.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 08/04/2012 Português
Relevância na Pesquisa
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We propose a potentially practical scheme to simulate artificial Abelian gauge field for polaritons using a hybrid quantum system consisting of nitrogen-vacancy center ensembles (NVEs) and superconducting transmission line resonators (TLR). In our case, the collective excitations of NVEs play the role of bosonic particles, and our multiport device tends to circulate polaritons in a behavior like a charged particle in an external magnetic field. We discuss the possibility of identifying signatures of the Hofstadter "butterfly" in the optical spectra of the resonators, and analyze the ground state crossover for different gauge fields. Our work opens new perspectives in quantum simulation of condensed matter and many-body physics using hybrid spin-ensemble circuit quantum electrodynamics system. The experimental feasibility and challenge are justified using currently available technology.; Comment: 6 papes+supplementary material