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Creation and Evaluation of a Multi-sensory Virtual Assembly Environment

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International Journal of Automation and computing 2008年第2期5卷 163-173页

作者： adrian R L Travis Department of Engineering University of Cambridge

The multi-modal information presentation, integrated into the virtual environment （VE）, has potential for stimulating different senses, improving the user＇s impression of immersion, and increasing the amount of information that is accepted and processed by the user＇s perception system. The increase of the useful feedback information may reduce the user＇s cognitive load, thus enhancing the user＇s efficiency and performance while interacting with VEs. This paper presents our creation of a multi-sensory virtual assembly environment （VAE） and the evaluation of the effects of multi-sensory feedback on the usability. The VAE brings together complex technologies such as constraint-based assembly simulation, optical motion tracking technology, and real-time 3D sound generation technology around a virtual reality workbench and a common software platform. The usability evaluation is in terms of its three attributes： efficiency of use, user satisfaction, and reliability. These are addressed by using task completion times （TCTs）, questionnaires, and human performance error rates （HPERs）, respectively. Two assembly tasks have been used to perform the experiments, using sixteen participants. The outcomes showed that the multi-sensory feedback could improve the usability. They also indicated that the integrated feedback offered better usability than either feedback used in isolation. Most participants preferred the integrated feedback to either feedback （visual or auditory） or no feedback. The participants＇ comments demonstrated that nonrealistic or inappropriate feedback had negative effects on the usability, and easily made them feel frustrated. The possible reasons behind the outcomes are also analysed by using a unifying human computer interaction framework. The implications, concluded from the outcomes of this work, can serve as useful guidelines for improving VE system design and implementation.

关键词： Usability virtual environment (VE) assembly simulation multi-sensory feedback task performance

Building occupancy and energy consumption:Case studies across building types

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Energy and Built Environment 2021年第2期2卷 167-174页

作者： Sicheng Zhan adrian Chong Department of Building School of Design and EnvironmentNational University of Singapore4 Architecture DriveSingapore 117566Singapore

Past research has shown that occupancy information can be used to reduce building energy consumption through occupant-based controls and by mitigating wasteful occupant *** this study,we investigate the dynamic relationship between WiFi connection counts(as a proxy to occupancy)and building electricity consumption across four building typologies(office,lab,health center,and library).Our findings based on one year of data show a strong positive linear correlation between electricity consumption and WiFi count across all four building when the building is in *** data exploration also indicates higher interactions between occupants with the plug and lighting loads in office and lab space types as compared to in a health center and a ***,using principal component analysis(PCA)for feature extraction followed by Density-based spatial clustering of applications with noise(DBSCAN),we show that distinct clusters could be generated,characterized by an increase in the between-cluster variance and smaller within-cluster ***,we apply linear regression to manifest how the clustering results can be used to better model the variables.

关键词： Occupancy WiFi Building energy Clustering Energy conservation

First thrust measurements in ionic multi-propeller rotational engines

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Propulsion and Power Research 2023年第1期12卷 44-58页

作者： adrian Ieta Marius Chirita Electrical and Computer Engineering Department SUNY OswegoOswegoNY 13126-3599USA Applied Physics/Condensed Matter Department National Institute for Research and Development in Electrochemistry and Condensed MatterTimisoaraRO-300224Romania

Rotary ionic engines(RIEs)with multi-coaxial contra-rotating propellers(12.6 cm diameter)and their axial thrust are investigated in laboratory conditions,in air at atmospheric pressure,for the first *** goal is to evaluate more advantageous configurations that may be scaled up and further help with development of rotary ionic *** propellers are designed with regular pin-emitter electrodes placed coaxially inside a cylindrical collector *** high voltage is applied,propellers spin generating conventional axial thrust which is measured with an electronic scale in a“see-saw”*** to 40 mN thrust was obtained in single propeller RIE at 2600 rpm,0.34 mA,37.5 kV,and an optimal collector electrode diameter of 17 *** thrust can be obtained with two and three propellers at constant current per propeller but at a decreased *** the axial propeller-separation showed that propeller-interaction is minimal above 5 ***-to-power and thrust-tocurrent ratios were calculated and *** experimentally confirm here for the first time that within certain limits,the thrust-to-power variation can be assessed by the propeller kinetic energy-to-power ratio and also by the impedance of the gap(voltage-to-current ratio).A comparison of RIE arrays performance with one,two,and three coaxial propellers and the same total number of propellers per array(six)is also *** arrays with multi-coaxial propellers can provide larger thrust densities than single-propeller ***,arrays employing two coaxial propeller unit may be more weight effective.

关键词： Ionic wind EHD pump Electrohydrodynamics Corona discharge Thrust-to-power Propeller Ion propulsion Plasma thrusters Electroaerodynamic thrusters Ionocraft

AutoBPS-BIM:A toolkit to transfer BIM to BEM for load calculation and chiller design optimization

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Building Simulation 2023年第7期16卷 1287-1298页

作者： Zhihua Chen Zhang Deng adrian Chong Yixing Chen College of Civil Engineering Hunan UniversityChangshaHunan 410082China Key Laboratory of Building Safety and Energy Efficiency(Hunan University) Ministry of EducationChina Department of Building National University of Singapore4 Architecture Drive117566Singapore

This study developed a rapid building modeling tool,AutoBPS-BIM,to transfer the building information model(BIM)to the building energy model(BEM)for load calculation and chiller design *** eight-storey office building in Beijing,33.2 m high,67.2 m long and 50.4 m wide,was selected as a case study ***,a module was developed to transfer BIM in IFC format into BEM in *** air volume systems were selected for the air system,while water-cooled chillers and boilers were used for the central *** EnergyPlus model calculated the heating and cooling loads for each space as well as the energy consumption of the central ***,a chiller optimization module was developed to select the optimal chiller design for minimizing energy consumption while maintaining thermal *** available chillers were included,with capacities ranging from 471 kW to 1329 *** results showed that the cooling loads of the spaces ranged from 33 to 100 W/m^(2) with a median of 45 W/m^(2),and the heating load ranged from 37 to 70 W/m^(2) with a median of 52 W/m^(2).The central plant’s total cooling load under variable air volume systems was 1400 *** with the static load calculation method,the dynamic method reduced 33%of the chiller design *** two chillers were used,different chiller combinations’annual cooling energy consumption ranged from 10.41 to 11.88,averaging 11.12 kWh/m^(2).The lowest energy consumption was 10.41 kWh/m^(2) when two chillers with 538 kW and 1076 kW each were *** the proper chiller number with different capacities was critical to achieving lower energy consumption,which achieved 12.6%cooling system energy consumption reduction for the case study *** study demonstrated that AutoBPS-BIM has a large potential in modeling BEM and optimizing chiller design.

关键词： BIM building energy model EnergyPlus chiller design optimization AutoBPS-BIM

On the evolution of terrestrial planets:Bi-stability,stochastic effects,and the non-uniqueness of tectonic states

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Geoscience Frontiers 2018年第1期9卷 91-102页

作者： Matthew B.Weller adrian Lenardic Institute for Geophysics University of Texas at AustinUSA Lunar and Planetary Institute HoustonTXUSA Department of Earth Science Rice UniversityHoustonTX 77005USA

The Earth is the only body in the solar system for which significant observational constraints are accessible to such a degree that they can be used to discriminate between competing models of Earth's tectonic *** is a natural tendency to use observations of the Earth to inform more general models of planetary ***,our understating of Earth's evolution is far from *** recent years,there has been growing geodynamic and geochemical evidence that suggests that plate tectonics may not have operated on the early Earth,with both the timing of its onset and the length of its activity far from ***,the potential of tectonic bi-stability(multiple stable,energetically allowed solutions)has been shown to be dynamically viable,both from analytical analysis and through numeric experiments in two and three *** indicates that multiple tectonic modes may operate on a single planetary body at different times within its temporal *** also allows for the potential that feedback mechanisms between the internal dynamics and surface processes(e.g.,surface temperature changes driven by long term climate evolution),acting at different thermal evolution times,can cause terrestrial worlds to alternate between multiple tectonic states over giga-year *** implication within this framework is that terrestrial planets have the potential to migrate through tectonic regimes at similar‘thermal evolution times'(e.g.,points were they have a similar bulk mantle temperature and energies),but at very different'temporal times'(time since planetary formation).It can be further shown that identical planets at similar stages of their evolution may exhibit different tectonic regimes due to random ***,we will discuss constraints on the tectonic evolution of the Earth and present a novel framework of planetary evolution that moves toward probabilistic arguments based on general physical principals,as opposed to particular rheol

关键词： Planetary interiors Mantle convection Lid-state Bi-stability Thermal evolution

The dispersion of surface contaminants by Stokes drift in random waves

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Acta Oceanologica Sinica 2018年第7期37卷 55-61页

作者： HUANG Guoxing LAW Wing-Keung adrian State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024 China State Key Laboratory of Hydrology Water Resources and Hydraulics Engineering Nanjing 210029 China School of Civil and Environmental Engineering Nanyang Technological University Singapore 639798 Singapore

Contaminants that are floating on the surface of the ocean are subjected to the action of random *** the literature,it has been asserted by researchers that the random wave action will lead to a dispersion mechanism through the induced Stokes drift,and that this dispersion mechanism may have the same order of significance comparable with the others means due to tidal currents and *** is investigated whether or not surface floating substances will disperse in the random wave environment due to the induced Stokes *** analytical derivation is first performed to obtain the drift velocity under the random *** the analysis,it is shown that the drift velocity is a time-independent value that does not possess any fluctuation given a specific wave energy ***,the random wave drift by itself should not have a dispersive effect on the surface floating *** were then conducted with small floating objects subjected to P-M spectral waves in a laboratory wave flume,and the experimental results reinforced the conclusion drawn.

关键词： dispersion surface contaminants random wave Stokes drift

Antifragility Analysis and Measurement Framework for Systems of Systems

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International Journal of Disaster Risk Science 2013年第4期4卷 159-168页

作者： John Johnson adrian V.Gheorghe Engineering Management and Systems Engineering Department Old Dominion University Norfolk VA 23529 USA

The twenty-first century is defined by the social and technical hazards we face.A hazardous situation is a condition,or event,that threatens the well-being of people,organizations,societies,environments,and *** most extreme of the hazards are considered X-Events and are an exogenous source of extreme stress to a system.X-Events can also be the unintended outputs of a system with both positive(serendipitous) and negative(catastrophic) *** can vary in their ability to withstand these stress *** ability exists on a continuum of fragility that ranges from fragile(degrading with stress),to robust(unchanged by stress),to antifragile(improving with stress).The state of the art does not include a method for analyzing or measuring *** that “what we measure we will improve,” the absence of a measurement approach limits the effectiveness of governance in making our systems less fragile and more robust if not *** authors present an antifragile system simulation model,and propose a framework for analyzing and measuring antifragility based on system of systems *** framework reduces a multidimensional concept of fragility into a two-dimensional continuous interval scale.

关键词： extreme unchanged consequences

PREBIOTICS:DEFINITION,EXPLANATION AND EVALUATION

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营养学报 2023年第6期45卷 606-614页

作者： Robert adrian Rastall Food Biotechnology University of ReadingUK

The evolution of the prebiotic concept The idea that the bacteria that live in one’s gut may have an impact on health is far from *** pioneering Japanese microbiologist Mitsuoka realised in the 1960s that the activities and metabolites produced by the gut bacteria could have quite profound impacts on health^([1-2]).More significantly he realised that the activities of these microorganisms could be manipulated by the diet(Fig.1).

关键词： profound Japanese EVAL

Dispersion in oscillatory electro-osmotic flow through a parallel-plate channel with kinetic sorptive exchange at walls

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Journal of Hydrodynamics 2014年第3期26卷 363-373页

作者： SONG Jie 吴朝安 LAW Wing-Keung adrian School of Civil and Environmental Engineering Nanyang Technological University Department of Mechanical Engineering The University of Hong Kong

Dispersion in time-oscillatory electro-osmotic flows in a slit micro-channel under the effect of kinetic sorptive exchange at walls is theoretically investigated using the homogenization method. The two walls of the channel are considered to be made up of different materials, and therefore have different zeta potentials and sorption coefficients. A general expression for the Taylor dispersion coefficient under different zeta potentials as well as various sorption conditions at the walls is derived analytically. The dispersion coefficient is found to be dependent on the oscillation frequency, the Debye parameter, the species partition coefficient, the reaction kinetics and the ratio of the wall potentials. The results demonstrate that the presence of wall sorption tends to enhance the dispersion when the oscillation frequency is low, but the effect is negligible in high-frequency oscillatory flows. Moreover, it is found that the dispersion coefficient could be significantly changed by adjusting the relative wall potentials for low-frequency flows.

关键词： oscillatory electro-osmotic flows dispersion sorptive walls homogenization method