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3D bare-hand interactions enabling ubiquitous interactions with smart objects

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Advances in Manufacturing 2020年第2期8卷 133-143页

作者： S.k.Ong X.Wang A.Y.c.Nee Department of Mechanical Engineering Faculty of EngineeringNational University of SingaporeSingapore

Ubiquitous augmented reality(UAR)implementation can benefit smart shop floor operations *** from a user's first-person view can support and provide the user with suitable and comprehensive information without him/her being distracted from ongoing tasks.A natural hand-based interaction interface,namely,a mobile bare-hand interface(MBHI),is proposed to assist a user in exploring and navigating a large amount of information for a task in the user's first-person *** integration of a smart shop floor and UAR-based MBHI is particularly challenging.A real shop floor environment is composed of challenging conditions for the implementation of UAR,e.g.,messy backgrounds and significant changes in illumination ***,the MBHI is required to provide precise and quick responses to minimize the dificulty of a user's *** this study,a wearable UAR system integrated with an MBH is proposed to augment the shop floor environment with smart information.A case study is implemented to demonstrate the practicality and effectiveness of the proposed UAR and MBHI system.

关键词： Augmented reality(AR) Mobile bare-hand interaction(MBH) Smart objects(SOs) Manufacturing shop-floor

Near resonance vibration isolation on a levered-dual response(LEDAR)coulomb-damped system by differential preloads/offsets in linear springs

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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 1033-1050页

作者： T.I.TOLUWALOJU c.k.THEIN D.HALIM Department of Mechanical Materials and Manufacturing EngineeringUniversity of Nottingham Ningbo ChinaNingbo 315100Zhejiang ProvinceChina Nottingham Ningbo china Beacons of Excellence Research and Innovation Institute University of Nottingham Ningbo ChinaNingbo 315048Zhejiang ProvinceChina

The levered-dual response(LEDAR)coulomb-damped system attains near resonant vibration isolation by differential preloads/offsets in linear *** takes the advantages of both the preloads/offsets in linear springs and the guiderail friction for realizing different levels of vibration *** isolation capacities are investigated on the strategies with both the horizontal and vertical guiderails,with the horizontal rail only,and without *** compressive preloads generally result in the consumption of most of the initial excitation energy so as to overcome the potential *** isolation onsets at the frequency ratio of 1∓0.095 on the left-hand side(LHS)and the right-hand side(RHS)of the lever are relative to the load plate *** observed near resonant isolation thus makes the LEDAR system a candidate for the isolation of the mechanical systems about resonance while opening a path for simultaneous harvesterisolation functions and passive functions at extreme frequencies.

关键词： lever ratio coulomb damping preload tension/compression isolation band/depth offset potential

Discrimination of membrane antigen affinity by B cells requires dominance of kinetic proofreading over serial engagement

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cellular & Molecular Immunology 2012年第1期9卷 62-74页

作者： Philippos k Tsourkas Wanli Liu Somkanya c Das Susan k Pierce Subhadip Raychaudhuri Department of Biomedical Engineering University of CaliforniaDavisCAUSA Laboratory of Immunogenetics National Institute of Allergy and Infectious DiseasesNational Institutes of HealthRockvilleMDUSA

B-cell receptor signaling in response to membrane-bound antigen increases with antigen affinity,a process known as affinity *** use computational modeling to show that B-cell affinity discrimination requires that kinetic proofreading predominate over serial *** find that if B-cell receptors become signaling-capable immediately upon antigen binding,which results in decreasing serial engagement as affinity increases,then increasing affinity can lead to weaker ***,antigen must stay bound to B-cell receptors for a threshold time of several seconds before becoming signaling-capable,a process similar to kinetic *** process overcomes the loss in serial engagement due to increasing antigen affinity,and replicates the monotonic increase in B-cell signaling with increasing affinity that has been observed in B-cell activation *** finding matches well with the experimentally observed time(,20 s)required for the B-cell receptor signaling domains to undergo antigen and lipid raft-mediated conformational changes that lead to Src-family kinase *** hypothesize that the physical basis for a threshold time of antigen binding might lie in the formation timescale of B-cell receptor *** time required for dimer formation decreases with increasing antigen affinity,thereby resulting in shorter threshold antigen binding times as affinity *** an affinity-dependent kinetic proofreading requirement results in affinity discrimination very similar to that observed in biological experiments.B-cell affinity discrimination is critical to the process of affinity maturation and the production of high-affinity antibodies,and thus our results have important implications in applications such as vaccine design.

关键词： computational modeling Monte carlo lymphocyte signaling Lyn Syk

Synthesis and Magnetic Properties of Nanoparticles of Fe-co Alloys and Their Oxides Prepared by chemical Vapor condensation

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Journal of Materials Science & Technology 2004年第4期20卷 459-462页

作者： ZhenhuaWANG ZhidongZHANG c.J.choi B.k.kim J.c.kim ShenyangNationalLaboratoryforMaterialsScienceandInternationalcentreforMateri~alsPhysics InstituteofMetalResearchChineseAcademyofSciencesShenyang110016China koreaInstituteofMachineryandMaterials 66Sangnam-DongChangwonKyungnam641-010Korea

Nanoparticles of Fe-co alloys and their oxides with the particle size below 20 nm were prepared by chemical vapor condensation process. The pure Ar, Ar+1%O2, Ar+3%O2 and Ar+6%O2 were used as carrier gases, with iron carbonyl and cobalt carbonyl as the precursors. XRD patterns showed that Fe-co metallic nanoparticles were synthesized by using pure Ar as carrier gas, and only metal oxides were obtained using Ar+(>3)%O2 as carrier gas. The HRTEM images and TG-DTA curves were used to study the core-shell structure of the different nanoparticles. The nanoparticles obtained in pure Ar consist of black core and light shell with thickness of 2~4 nm. However, in the particles obtained in Ar+6%02, the oxides core with visible lattice fringes are surrounded by thin shell.

关键词： Fe-co Nanoparticles HRTEM cVc

Study of deposition of fine sediment within the pores of a coarse sediment bed stream

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International Journal of Sediment Research 2013年第2期28卷 210-219页

作者： N.k.kHULLAR U.c.kOTHYARI k.G.Ranga RAJU Department of civil Engineering PAU Ludhiana-India Prof.Dr. Department of civil Engineering IIT Roorkee-India Prof.Dr. Department of civil Engineering IIT Roorkee-India Formerly Prof.Dr.

Elaborate experiments were performed in a 30 m long,0.5 m deep and 0.2 m wide laboratory flume to study the process of infiltration of fine sediment into the pores of coarse sediment forming the channel bed *** concentrations of suspended load of fine sediment of size 0.064 mm were passed over the channel bed made up of three different types of coarse sediments;two uniform and one *** proportion of fine sediment infiltrated into the pores of bed material for each equilibrium concentration of suspended load of fine sediment in the flow was studied during several experimental *** proportion of fine sediment within the pores of bed material increased with an increase in the equilibrium concentration of suspended load of fine sediment in the *** process continued till the pores within the coarse sediment bed were filled up to the capacity with the fine sediment transported by the flow in *** theoretical value was identified for limit for maximum proportion of fine sediment that can be present within the pores of bed *** further increase in the concentration of suspended load of fine sediment in the flow,deposition of fine sediment occurs on the surface of the flume bed in the form of ripples of the fine *** condition is defined as ’depositional condition’.Experimental observations on these and related aspects are presented herein.

关键词： Fine sediment Flume experiment Bed material concentration of suspended sediment Deposition condition

FREE TRANSVERSE VIBRATIONS OF A DOUBLE-WALLED cARBON NANOTUBE:GRADIENT AND INTERNAL INERTIA EFFEcTS

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Acta Mechanica Solida Sinica 2014年第4期27卷 345-352页

作者： k.Y.Xu k.A.Alnefaie N.H.Abu-Hamdeh k.H.Almitani E.c.Aifantis Department of Mechanics Shanghai University Department of Mechanical Engineering King Abdulaziz University Jeddah 21589 Saudi Arabia Lab of Mechanics and Materials Polytechnic School Aristotle University Thessaloniki 54124 Greece

This is a modest contribution on higher-order continuum theory for predicting size effects in small-scale objects. It relates to a preceding article of the journal by the same authors（AMSS, 2013, 26： 9-20） which considered the longitudinal dynamical analysis of a gradient elastic fiber but, in addition to an internal length, an internal time parameter is also introduced to model delay/acceleration effects associated with the underlying microstructure. In particular, the free transverse vibration of a double-walled carbon nanotube（DWNT） is studied by employing gradient elasticity with internal inertia. The inner and outer carbon nanotubes are modeled as two individual elastic beams interacting with each other through van der Waals（vdW） forces. General explicit expressions are derived for the natural frequencies and the associated inner-to-outer tube amplitude ratios for the case of simply supported DWNTs. The effects of internal length（or scale）and internal time（or inertia） on the vibration behavior are evaluated. The results indicate that the internal length and time parameters of the adopted strain gradient-internal inertia generalized elasticity model have little influence on the lower order coaxial and noncoaxial vibration modes,but a significant one on the higher order modes.

关键词： carbon nanotubes gradient elasticity internal inertia vibration behavior

Which neurological abnormalities and neuropsychological impairments share the same substrate in psychosis?

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chinese Science Bulletin 2011年第32期56卷 3372-3375页

作者： DAZZAN Paola cHAN Raymond c k Department of Psychosis Studies Institute of Psychiatry King's College London UK Neuropsychology and Applied cognitive Neuroscience Laboratory Key Laboratory of Mental Health Institute of Psychology Chinese Academy of Sciences Beijing 100101 China

Approximately 60% of subjects with schizophrenia present minor neurological signs (neurological soft signs, NSS), which include abnormalities in sensory and motor performance indicative of a non-specific cerebral dysfunction. These are also present in healthy individuals and relatives of patients with psychosis, at significantly lower rates. The excess of NSS in psychosis may be a potential endophenotype for this disorder, and reflect the same neurodevelopmental brain dysfunction that also underlies the cognitive deficits consistently reported in psychosis. To establish whether neurological and cognitive dysfunction meet the essential criterion required for a refined endophenotype for psychosis, the association with the illness, we explored evidence that certain neurological and cognitive deficits co-occur in affected individuals. This evidence suggests that signs of motor dysfunctions may be specific to patients with psychosis, in whom they are associated with dysfunction in cognitive tasks requiring motor skills. Thus, they may form a promising candidate endophenotype for psychosis.

关键词：精神病患者神经系统心理障碍异常脑功能障碍基板共享运动性能

Analysis Scheme for Density Modulation Experiments to Study Particle confinements

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Plasma Science and Technology 2006年第1期8卷 65-71页

作者： k. TANAkA c. MIcHAEL k. kAWANATA T. TOkUZAWAI M. SHOJI k. TOI 高翔揭银先 National Institute for Fusion Science Toki 509-5292 Japan Institute of Plasma Physics Chinese Academy of Science Hefei 230031 China

Density modulation experiments are powerful experimental schemes for the study of particle transport. The diffusion coefficients （D） and convection velocity （V）, which cannot be evaluated from the particle balance in the equilibrium state, can be obtained separately. Further, the estimated values of D and V are determined independent of the absolute value of the particle source rate, which is difficult to obtain experimentally. However, the sensitivities and interpretation of D and V from the modulation experiments need to be considered. This paper describes numerical techniques for solving the particle balance equation of the modulation components. Examples of the analysis are shown regarding the data of LHD experiments, and the results of the modulation experiments are discussed.

关键词： density modulation, particle confinements, diffusion coefficient convection velocity

Tribological and vibrational characteristics of AISI 316L tested at elevated temperature and 600 Torr vacuum

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Defence Technology（防务技术） 2019年第1期15卷 58-64页

作者： k.Arul Raj M.P.Arunkumar P.k.c.kanigalpula M.karthikeyan Department of Mechanical Engineering Koneru Lakshmaiah Education Foundation Department of Mechanical Engineering RajaRajeswari College of Engineering

Friction and wear studies enable the investigation of material interaction between two sliding surfaces in contact. In the present investigation, the coefficient of friction and the wear resistance of AISI 316 L parts were studied under self-mating, dry sliding conditions using a pin-on-disc type configuration. The experiments were conducted at vacuum based high temperature pin-on-disc tribometer. The 4 mm diameter pin and 180 mm diameter disc were subjected to varying sliding velocities(0.5, 0.75 and 1.5 m/s) and were operated in 200, 400, 500 and 580 ℃ temperature at 600 Torr vacuum. The variation of specific wear rates with sliding velocities and different environmental conditions was studied. The morphology of sliding/rubbed surfaces was observed using Scanning Electron Microscope. In summary, it was found that a severe to mild wear transition occurred in sliding under operating conditions. Increased wear rates have been observed for 500 and 580 ℃ with increasing sliding velocity. Adhesive wear has been found to be predominant at 500 and 580 ℃ where as de-lamination has been observed at ambient temperature,200 and 400 ℃ in vacuum. The present paper also carried out the numerical analysis of the vibration behavior of AISI 316 L under thermal environment. Results revealed that at high temperature vibrational amplitude and natural frequency is significantly reduced. This can be attributed to the reduction in stiffness of the material at elevated temperatures. This high amplitude vibration during service can lead to high wear rate.

关键词： Pin-on-disc Sliding wear Vacuum De-lamination Scanning electron microscope Vibration