4,894 research outputs found

    Real time multimodal interaction with animated virtual human

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    This paper describes the design and implementation of a real time animation framework in which animated virtual human is capable of performing multimodal interactions with human user. The animation system consists of several functional components, namely perception, behaviours generation, and motion generation. The virtual human agent in the system has a complex underlying geometry structure with multiple degrees of freedom (DOFs). It relies on a virtual perception system to capture information from its environment and respond to human user's commands by a combination of non-verbal behaviours including co-verbal gestures, posture, body motions and simple utterances. A language processing module is incorporated to interpret user's command. In particular, an efficient motion generation method has been developed to combines both motion captured data and parameterized actions generated in real time to produce variations in agent's behaviours depending on its momentary emotional states

    Adorning VRML worlds with environmental aspects

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    Distributed VR for collaborative design and manufacturing

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    Virtual Manufacturing (VM) applies Virtual Reality (VR) technology to provide a digital manufacturing solution in both 3D visual and interactive ways. It makes VR no longer a state-of-the art but rather an innovation technology to support modern industry. With the rapid growth of network technology and Web 3D graphics techniques, we propose a cost-effective distributed VM system for Small and Medium-sized Enterprises (SMEs) with limited equipment, funds and technical capabilities. The system enables SMEs to perform collaborative tasks including product design, manufacturing and resources sharing through the World Wide Web (WWW) in lower cost. This paper describes the design and critical integration issues of the system and the use of the Web 3D technology - X3D. It also evaluates the distributed VM system by comparing it to the conventional standalone CAD/CAM system

    AR-based Technoself Enhanced Learning Approach to Improving Student Engagement

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    The emerging technologies have expanded a new dimension of self – ‘technoself’ driven by socio-technical innovations and taken an important step forward in pervasive learning. Technology Enhanced Learning (TEL) research has increasingly focused on emergent technologies such as Augmented Reality (AR) for augmented learning, mobile learning, and game-based learning in order to improve self-motivation and self-engagement of the learners in enriched multimodal learning environments. These researches take advantage of technological innovations in hardware and software across different platforms and devices including tablets, phoneblets and even game consoles and their increasing popularity for pervasive learning with the significant development of personalization processes which place the student at the center of the learning process. In particular, augmented reality (AR) research has matured to a level to facilitate augmented learning, which is defined as an on-demand learning technique where the learning environment adapts to the needs and inputs from learners. In this paper we firstly study the role of Technology Acceptance Model (TAM) which is one of the most influential theories applied in TEL on how learners come to accept and use a new technology. Then we present the design methodology of the technoself approach for pervasive learning and introduce technoself enhanced learning as a novel pedagogical model to improve student engagement by shaping personal learning focus and setting. Furthermore we describe the design and development of an AR-based interactive digital interpretation system for augmented learning and discuss key features. By incorporating mobiles, game simulation, voice recognition, and multimodal interaction through Augmented Reality, the learning contents can be geared toward learner's needs and learners can stimulate discovery and gain greater understanding. The system demonstrates that Augmented Reality can provide rich contextual learning environment and contents tailored for individuals. Augment learning via AR can bridge this gap between the theoretical learning and practical learning, and focus on how the real and virtual can be combined together to fulfill different learning objectives, requirements, and even environments. Finally, we validate and evaluate the AR-based technoself enhanced learning approach to enhancing the student motivation and engagement in the learning process through experimental learning practices. It shows that Augmented Reality is well aligned with constructive learning strategies, as learners can control their own learning and manipulate objects that are not real in augmented environment to derive and acquire understanding and knowledge in a broad diversity of learning practices including constructive activities and analytical activities

    Partitioning technique for a discrete quantum system

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    We develop the partitioning technique for quantum discrete systems. The graph consists of several subgraphs: a central graph and several branch graphs, with each branch graph being rooted by an individual node on the central one. We show that the effective Hamiltonian on the central graph can be constructed by adding additional potentials on the branch-root nodes, which generates the same result as does the the original Hamiltonian on the entire graph. Exactly solvable models are presented to demonstrate the main points of this paper.Comment: 7 pages, 2 figure

    Metabolic engineering of clostridium cellulovorans to improve butanol production by consolidated bioprocessing.

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    Clostridium cellulovorans DSM 743B can produce butyrate when grown on lignocellulose, but it can hardly synthesize butanol. In a previous study, C. cellulovorans was successfully engineered to switch the metabolism from butyryl-CoA to butanol by overexpressing an alcohol aldehyde dehydrogenase gene adhE1 from Clostridium acetobutylicum ATCC 824; however, its full potential in butanol production is still unexplored. In the study, a metabolic engineering approach based on a push-pull strategy was developed to further enhance cellulosic butanol production. In order to accomplish this, the carbon flux from acetyl-CoA to butyryl-CoA was pulled by overexpressing a trans-enoyl-coenzyme A reductase gene (ter), which can irreversibly catalyze crotonyl-CoA to butyryl-CoA. Then an acid reassimilation pathway uncoupled with acetone production was introduced to redirect the carbon flow from butyrate and acetate toward butyryl-CoA. Finally, xylose metabolism engineering was implemented by inactivating xylR (Clocel_0594) and araR (Clocel_1253), as well as overexpressing xylT (CA_C1345), which is expected to supply additional carbon and reducing power for CoA and butanol synthesis pathways. The final engineered strain produced 4.96 g/L of n-butanol from alkali extracted corn cobs (AECC), increasing by 235-fold compared to that of the wild type. It serves as a promising butanol producer by consolidated bioprocessing

    Determination of Carrier-Envelope Phase of Relativistic Few-Cycle Laser Pulses by Thomson Backscattering Spectroscopy

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    A novel method is proposed to determine the carrier-envelope phase (CEP) of a relativistic few-cycle laser pulse via the central frequency of the isolated light generated from Thomson backscattering (TBS). We theoretically investigate the generation of a uniform flying mirror when a few-cycle drive pulse with relativistic intensity (I > 10^{18} {{\rm{W}} \mathord{/ {\vphantom {{\rm{W}} {{\rm{cm}}^{\rm{2}}}}}. \kern-\nulldelimiterspace} {{\rm{cm}}^{\rm{2}}}}) interacts with a target combined with a thin and a thick foil. The central frequency of the isolated TBS light generated from the flying mirror shows a sensitive dependence on the CEP of the drive pulse. The obtained results are verified by one dimensional particle in cell (1D-PIC) simulations

    TargeTron technology applicable in solventogenic clostridia: Revisiting 12 years’ advances

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    Clostridium has great potential in industrial application and medical research. But low DNA repair capacity and plasmids transformation efficiency severely delayed development and application of genetic tools based on homologous recombination (HR). TargeTron is a gene editing technique dependent on the mobility of group II introns, rather than homologous recombination, which made it very suitable for gene disruption of Clostridium. The application of TargeTron technology in Clostridium was academically reported in 2007 and this tool has been introduced in various clostridia as it is easy to operate, time-saving, and reliable. TargeTron has made great progress in solventogenic Clostridium in the aspects of acetone-butanol-ethanol (ABE) fermentation pathway modification, important functional genes identification, and xylose metabolic pathway analysis & reconstruction. In the review, we revisited 12 years' advances of TargeTron technology applicable in solventogenic Clostridium, including its principle, technical characteristics, application and efforts to expand its capabilities, or to avoid potential drawbacks. Some other technologies as putative competitors or collaborators are also discussed. We believe that TargeTron combined with CRISPR/Cas-assisted gene/base editing and gene-expression regulation system will make a better future for clostridial genetic modification

    Trigger efficiencies at BES III

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    Trigger efficiencies at BES III were determined for both the J/psi and psi' data taking of 2009. Both dedicated runs and physics datasets are used; efficiencies are presented for Bhabha-scattering events, generic hadronic decay events involving charged tracks, dimuon events and psi' -> pi+pi-J/psi, J/psi -> l+l- events (l an electron or muon). The efficiencies are found to lie well above 99% for all relevant physics cases, thus fulfilling the BES III design specifications.Comment: 6 pages, 4 figure

    Suppression of Superconducting Critical Current Density by Small Flux Jumps in MgB2MgB_2 Thin Films

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    By doing magnetization measurements during magnetic field sweeps on thin films of the new superconductor MgB2MgB_2, it is found that in a low temperature and low field region small flux jumps are taking place. This effect strongly suppresses the central magnetization peak leading to reduced nominal superconducting critical current density at low temperatures. A borderline for this effect to occur is determined on the field-temperature (H-T) phase diagram. It is suggested that the small size of the flux jumps in films is due to the higher density of small defects and the relatively easy thermal diffusion in thin films in comparison with bulk samples.Comment: 7 figures Phys. Rev. B accepted scheduled issue: 01 Feb 200
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