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Sample records for vibro-acoustic virtual sensor

  1. Vibro-acoustics

    CERN Document Server

    Nilsson, Anders

    2015-01-01

    This three-volume book gives a thorough and comprehensive presentation of vibration and acoustic theories. Different from traditional textbooks which typically deal with some aspects of either acoustic or vibration problems, it is unique of this book to combine those two correlated subjects together. Moreover, it provides fundamental analysis and mathematical descriptions for several crucial phenomena of Vibro-Acoustics which are quite useful in noise reduction, including how structures are excited, energy flows from an excitation point to a sound radiating surface, and finally how a structure radiates noise to a surrounding fluid. Many measurement results included in the text make the reading interesting and informative. Problems/questions are listed at the end of each chapter and the solutions are provided. This will help the readers to understand the topics of Vibro-Acoustics more deeply. The book should be of interest to anyone interested in sound and vibration, vehicle acoustics, ship acoustics and inter...

  2. Vibro-acoustics of lightweight sandwich structures

    CERN Document Server

    Lu, Tianjian

    2014-01-01

    Vibro-Acoustics of Lightweight Sandwich Structures introduces the study of the coupled vibration and acoustic behavior of lightweight sandwich structures in response to harmonic force and sound pressure. This book focuses on the theoretical modeling and experimental investigation of lightweight sandwich structures in order to provide a predictive framework for vibro-acoustic characteristics of typical engineering structures. Furthermore, by developing solution tools, it concentrates on the influence of key systematic parameters leading to effective guidance for optimal structure design toward lightweight, high-stiffness and superior sound insulation capability. This book is intended for researchers, scientists, engineers and graduate students in mechanical engineering especially in structural mechanics, mechanics and acoustics. Fengxian Xin and Tianjian Lu both work at the School of Aerospace, Xi’an Jiaotong University.

  3. Virtual sensors for active noise control in acoustic-structural coupled enclosures using structural sensing: part II--Optimization of structural sensor placement.

    Science.gov (United States)

    Halim, Dunant; Cheng, Li; Su, Zhongqing

    2011-04-01

    The work proposed an optimization approach for structural sensor placement to improve the performance of vibro-acoustic virtual sensor for active noise control applications. The vibro-acoustic virtual sensor was designed to estimate the interior sound pressure of an acoustic-structural coupled enclosure using structural sensors. A spectral-spatial performance metric was proposed, which was used to quantify the averaged structural sensor output energy of a vibro-acoustic system excited by a spatially varying point source. It was shown that (i) the overall virtual sensing error energy was contributed additively by the modal virtual sensing error and the measurement noise energy; (ii) each of the modal virtual sensing error system was contributed by both the modal observability levels for the structural sensing and the target acoustic virtual sensing; and further (iii) the strength of each modal observability level was influenced by the modal coupling and resonance frequencies of the associated uncoupled structural/cavity modes. An optimal design of structural sensor placement was proposed to achieve sufficiently high modal observability levels for certain important panel- and cavity-controlled modes. Numerical analysis on a panel-cavity system demonstrated the importance of structural sensor placement on virtual sensing and active noise control performance, particularly for cavity-controlled modes.

  4. Vibro-acoustic performance of newly designed tram track structures

    Science.gov (United States)

    Haladin, Ivo; Lakušić, Stjepan; Ahac, Maja

    2017-09-01

    Rail vehicles in interaction with a railway structure induce vibrations that are propagating to surrounding structures and cause noise disturbance in the surrounding areas. Since tram tracks in urban areas often share the running surface with road vehicles one of top priorities is to achieve low maintenance and long lasting structure. Research conducted in scope of this paper gives an overview of newly designed tram track structures designated for use on Zagreb tram network and their performance in terms of noise and vibration mitigation. Research has been conducted on a 150 m long test section consisted of three tram track types: standard tram track structure commonly used on tram lines in Zagreb, optimized tram structure for better noise and vibration mitigation and a slab track with double sleepers embedded in a concrete slab, which presents an entirely new approach of tram track construction in Zagreb. Track has been instrumented with acceleration sensors, strain gauges and revision shafts for inspection. Relative deformations give an insight into track structure dynamic load distribution through the exploitation period. Further the paper describes vibro-acoustic measurements conducted at the test site. To evaluate the track performance from the vibro-acoustical standpoint, detailed analysis of track decay rate has been analysed. Opposed to measurement technique using impact hammer for track decay rate measurements, newly developed measuring technique using vehicle pass by vibrations as a source of excitation has been proposed and analysed. Paper gives overview of the method, it’s benefits compared to standard method of track decay rate measurements and method evaluation based on noise measurements of the vehicle pass by.

  5. Virtual sensors for active noise control in acoustic-structural coupled enclosures using structural sensing: robust virtual sensor design.

    Science.gov (United States)

    Halim, Dunant; Cheng, Li; Su, Zhongqing

    2011-03-01

    The work was aimed to develop a robust virtual sensing design methodology for sensing and active control applications of vibro-acoustic systems. The proposed virtual sensor was designed to estimate a broadband acoustic interior sound pressure using structural sensors, with robustness against certain dynamic uncertainties occurring in an acoustic-structural coupled enclosure. A convex combination of Kalman sub-filters was used during the design, accommodating different sets of perturbed dynamic model of the vibro-acoustic enclosure. A minimax optimization problem was set up to determine an optimal convex combination of Kalman sub-filters, ensuring an optimal worst-case virtual sensing performance. The virtual sensing and active noise control performance was numerically investigated on a rectangular panel-cavity system. It was demonstrated that the proposed virtual sensor could accurately estimate the interior sound pressure, particularly the one dominated by cavity-controlled modes, by using a structural sensor. With such a virtual sensing technique, effective active noise control performance was also obtained even for the worst-case dynamics. © 2011 Acoustical Society of America

  6. Vibro-acoustic Imaging at the Breazeale Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Smith, James Arthur [Idaho National Lab. (INL), Idaho Falls, ID (United States); Jewell, James Keith [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lee, James Edwin [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-01

    The INL is developing Vibro-acoustic imaging technology to characterize microstructure in fuels and materials in spent fuel pools and within reactor vessels. A vibro-acoustic development laboratory has been established at the INL. The progress in developing the vibro-acoustic technology at the INL is the focus of this report. A successful technology demonstration was performed in a working TRIGA research reactor. Vibro-acoustic imaging was performed in the reactor pool of the Breazeale reactor in late September of 2015. A confocal transducer driven at a nominal 3 MHz was used to collect the 60 kHz differential beat frequency induced in a spent TRIGA fuel rod and empty gamma tube located in the main reactor water pool. Data was collected and analyzed with the INLDAS data acquisition software using a short time Fourier transform.

  7. NuSTAR: Vibro-Acoustic Tests

    Energy Technology Data Exchange (ETDEWEB)

    Kasim, K.

    2004-09-03

    NuSTAR is a satellite that will be carrying X-ray optics that consist of many nested glass cylinders. Due to different acoustic environments, the glass may react such that cracks and/or fractures may form. Cracks and/or fractures in the glass would not allow the optic to work properly. Therefore, it is necessary to test the glass and optic prototypes to determine if they will be able to withhold when experiencing certain acoustic environments. The vibro-acoustic testing conducted at the Jet Propulsion Laboratory (JPL) in Pasadena determined that under the minimum workmanship acoustic environments, the glass on the optics will not fail. Overall, the results of the test were successful which gives confidence that when the satellite is launched into the air and then dropped into space, the glass in the optics will not fail.

  8. Velocity measurement by vibro-acoustic Doppler.

    Science.gov (United States)

    Nabavizadeh, Alireza; Urban, Matthew W; Kinnick, Randall R; Fatemi, Mostafa

    2012-04-01

    We describe the theoretical principles of a new Doppler method, which uses the acoustic response of a moving object to a highly localized dynamic radiation force of the ultrasound field to calculate the velocity of the moving object according to Doppler frequency shift. This method, named vibro-acoustic Doppler (VAD), employs two ultrasound beams separated by a slight frequency difference, Δf, transmitting in an X-focal configuration. Both ultrasound beams experience a frequency shift because of the moving objects and their interaction at the joint focal zone produces an acoustic frequency shift occurring around the low-frequency (Δf) acoustic emission signal. The acoustic emission field resulting from the vibration of the moving object is detected and used to calculate its velocity. We report the formula that describes the relation between Doppler frequency shift of the emitted acoustic field and the velocity of the moving object. To verify the theory, we used a string phantom. We also tested our method by measuring fluid velocity in a tube. The results show that the error calculated for both string and fluid velocities is less than 9.1%. Our theory shows that in the worst case, the error is 0.54% for a 25° angle variation for the VAD method compared with an error of -82.6% for a 25° angle variation for a conventional continuous wave Doppler method. An advantage of this method is that, unlike conventional Doppler, it is not sensitive to angles between the ultrasound beams and direction of motion.

  9. Vibro-acoustics of porous materials - waveguide modeling approach

    DEFF Research Database (Denmark)

    Darula, Radoslav; Sorokin, Sergey V.

    2016-01-01

    The porous material is considered as a compound multi-layered waveguide (i.e. a fluid layer surrounded with elastic layers) with traction free boundary conditions. The attenuation of the vibro-acoustic waves in such a material is assessed. This approach is compared with a conventional Biot's model...

  10. Vibro-acoustic modulation–based damage identification in a composite skin–stiffener structure

    NARCIS (Netherlands)

    Ooijevaar, T.H.; Rogge, M.D.; Loendersloot, Richard; Warnet, Laurent; Akkerman, Remko; Tinga, Tiedo

    2016-01-01

    Vibro-acoustic modulation–based damage identification relies on the modulation of a high-frequency carrier signal by an intenser low-frequency vibration signal due to damage-induced structural nonlinearities. A time domain analysis of the vibro-acoustic modulation phenomena was presented at multiple

  11. Damage imaging in nonlinear vibro-acoustic modulation tests

    Science.gov (United States)

    Pieczonka, Lukasz; Klepka, Andrzej; Uhl, Tadeusz; Staszewski, Wieslaw J.

    2015-03-01

    The paper deals with the nonlinear vibro-acoustic modulation technique (VAM) used for nondestructive damage detection in composites. In its original form the technique allows only for the determination of the presence of damage in a structure. This paper presents an enhancement of the technique that allows also for the determination of damage location. Experimental testing of the proposed procedure is performed on carbon fiber/epoxy laminated composite plates with barely visible impact damage that was generated in an impact test. Shearography was used to verify damage location. Piezoceramic actuators are used for vibration excitation and a scanning laser vibrometer is used for data acquisition.

  12. A Method of Abnormal States Detection Based on Adaptive Extraction of Transformer Vibro-Acoustic Signals

    Directory of Open Access Journals (Sweden)

    Liang Zou

    2017-12-01

    Full Text Available State monitoring is very important for the safe operation of high-voltage transformers. A non-contact vibro-acoustic detection method based on the Blind Source Separation (BSS was proposed in this paper to promote the development of transformer on-line monitoring technology. Firstly, the algorithm of Sparse Component Analysis (SCA was applied for the adaptive extraction of vibro-acoustic signals, which utilizes the sorted local maximum values of the potential function. Then, the operating states of the transformer were detected by analyzing the vibro-acoustic signal eigenvectors. Different conditions including running normally, increasing of transformer vibro-acoustic amplitude and changing of frequency component of transformer vibro-acoustic were simulated. Moreover, experiments were carried out in a 220 kV substation. The research results show that the number of mixed noise sources can be estimated and the transformer vibro-acoustic signal was always ranked first in the separation signals. The source signals were effectively separated from the mixed signals while all of the correlation coefficients are more than 0.98 and the quadratic residuals are less than −32 dB. As for the experiments, the vibro-acoustic signal was separated out successfully from two voice signals and two interference signals. The acoustic signal reflection is considered as the main cause of the signal interference, and the transformer volume source model is considered as the main reason of unstable vibro-acoustic signal amplitude. Finally, the simulated abnormal states of the transformer were well recognized and the state of the tested transformer was judged to be normal.

  13. Research activities on vibro-acoustics of satellites during rocket launch

    OpenAIRE

    Murakami, Keiichi; Inada, Yoshinobu; Aoyama, Takashi; Takahashi, Takashi; Aiso, Hideaki; 村上 桂一; 稲田 喜信; 青山 剛史; 高橋 孝; 相曽 秀昭

    2006-01-01

    A study to establish a prediction method for vibro-acoustics of satellites during rocket launch has been conducted using a multidisciplinary analysis method of fluid, acoustic, and vibration. This coupling method consists of following four elements: numerical analyses of (1) sound generation, (2) sound propagation, (3) sound permeation, and (4) vibro-acoustics of payload. In the sound generation analysis, it can be seen from FEM analysis of a simply modeled deflector that a strong resonance o...

  14. Utilization of old vibro-acoustic measuring equipment to grasp basic concepts of vibration measurements

    DEFF Research Database (Denmark)

    Darula, Radoslav

    2013-01-01

    The aim of the paper is to show that even old vibro-acoustic (analog) equipment can be used as a very suitable teaching equipment to grasp basic principles of measurements in an era, when measurement equipments are more-or-less treated as ‘black-boxes’, i.e. the user cannot see directly how...

  15. Vibro-Acoustic modulation based damage identification in a composite skin-stiffener structure

    NARCIS (Netherlands)

    Ooijevaar, T.H.; Loendersloot, Richard; Rogge, M.D.; Akkerman, Remko; Tinga, Tiedo; Le Cam, V.; Mevel, L.; Schoefs, F.

    2014-01-01

    The vibro-acoustic modulation method is applied to a composite skin-stiffener structure to investigate the possibilities to utilise this method for damage identification in terms of detection, localisation and damage quantification. The research comprises a theoretical part and an experimental part.

  16. Vibro-Acoustic Numerical Analysis for the Chain Cover of a Car Engine

    National Research Council Canada - National Science Library

    Enrico Armentani; Raffaele Sepe; Antonio Parente; Mauro Pirelli

    2017-01-01

    In this work, a vibro-acoustic numerical and experimental analysis was carried out for the chain cover of a low powered four-cylinder four-stroke diesel engine, belonging to the FPT (FCA Power Train) family called SDE (Small Diesel Engine...

  17. Vibro-acoustic model of an active aircraft cabin window

    Science.gov (United States)

    Aloufi, Badr; Behdinan, Kamran; Zu, Jean

    2017-06-01

    This paper presents modeling and design of an active structural acoustic control (ASAC) system for controlling the low frequency sound field transmitted through an aircraft cabin window. The system uses stacked piezoelectric elements arranged in a manner to generate out-of-plane actuation point forces acting on the window panel boundaries. A theoretical vibro-acoustic model for an active quadruple-panel system is developed to characterize the dynamic behavior of the system and achieve a good understanding of the active control performance and the physical phenomena of the sound transmission loss (STL) characteristics. The quadruple-panel system represents the passenger window design used in some classes of modern aircraft with an exterior double pane of Plexiglas, an interior dust cover pane and a glazed dimmable pane, all separated by thin air cavities. The STL characteristics of identical pane window configurations with different piezoelectric actuator sets are analyzed. A parametric study describes the influence of important active parameters, such as the input voltage, number and location of the actuator elements, on the STL is investigated. In addition, a mathematical model for obtaining the optimal input voltage is developed to improve the acoustic attenuation capability of the control system. In general, the achieved results indicate that the proposed ASAC design offers a considerable improvement in the passive sound loss performance of cabin window design without significant effects, such as weight increase, on the original design. Also, the results show that the acoustic control of the active model with piezoelectric actuators bonded to the dust cover pane generates high structural vibrations in the radiating panel (dust cover) and an increase in sound power radiation. High active acoustic attenuation can be achieved by designing the ASAC system to apply active control forces on the inner Plexiglas panel or dimmable panel by installing the actuators on the

  18. Vibro-acoustics of ribbed structures: A compact modal formulation for SEA models

    Science.gov (United States)

    Bremner, Paul G.

    Rib-stiffening of plates and shells is a structurally-efficient construction technique common to aerospace, shipbuilding, automotive, and many other industries. Engineers need to be able to design the vibro-acoustic behavior of these panel systems. That is, the panel vibration response to excitation by a sound pressure field and the sound radiated by panel vibration. The effect of adding rib-stiffeners to a uniform thickness, isotropic panel is to cause scattering of the panel free bending waves. The superposition of these wavefields can also be described by modal methods, if the panel has finite dimensions. The effect of rib stiffening is shown to be the re-distribution of resonant frequencies and mode shapes of the panel, which can significantly alter its noise and vibration character. This paper describes a compact modal method for description of the vibro-acoustics of ribbed panels which is currently implemented in the Statistical Energy Analysis modeling package AutoSEA.

  19. Vibro-acoustic condition monitoring of Internal Combustion Engines: A critical review of existing techniques

    Science.gov (United States)

    Delvecchio, S.; Bonfiglio, P.; Pompoli, F.

    2018-01-01

    This paper deals with the state-of-the-art strategies and techniques based on vibro-acoustic signals that can monitor and diagnose malfunctions in Internal Combustion Engines (ICEs) under both test bench and vehicle operating conditions. Over recent years, several authors have summarized what is known in critical reviews mainly focused on reciprocating machines in general or on specific signal processing techniques: no attempts to deal with IC engine condition monitoring have been made. This paper first gives a brief summary of the generation of sound and vibration in ICEs in order to place further discussion on fault vibro-acoustic diagnosis in context. An overview of the monitoring and diagnostic techniques described in literature using both vibration and acoustic signals is also provided. Different faulty conditions are described which affect combustion, mechanics and the aerodynamics of ICEs. The importance of measuring acoustic signals, as opposed to vibration signals, is due since the former seem to be more suitable for implementation on on-board monitoring systems in view of their non-intrusive behaviour, capability in simultaneously capturing signatures from several mechanical components and because of the possibility of detecting faults affecting airborne transmission paths. In view of the recent needs of the industry to (-) optimize component structural durability adopting long-life cycles, (-) verify the engine final status at the end of the assembly line and (-) reduce the maintenance costs monitoring the ICE life during vehicle operations, monitoring and diagnosing system requests are continuously growing up. The present review can be considered a useful guideline for test engineers in understanding which types of fault can be diagnosed by using vibro-acoustic signals in sufficient time in both test bench and operating conditions and which transducer and signal processing technique (of which the essential background theory is here reported) could be

  20. The Vibro-Acoustic Modelling of Slab Track with Embedded Rails

    Science.gov (United States)

    VAN LIER, S.

    2000-03-01

    The application of concrete slab track in railways has certain advantages compared with conventional ballasted track, but conventional slab track structures generally produce more noise than ballasted track. For this reason a “silent slab track” has been developed in the Dutch ICES “Stiller Treinverkeer” project (silent railway traffic) by optimizing the track. In the design, the rails are embedded in a cork-filled elastomeric material. The paper discusses the vibro-acoustic modelling of this track using the simulation package “TWINS”, combined with finite element techniques. The model evaluates the one-third octave band sound power spectrum radiated by train wheels and track, and provides for a tool to optimize the track design. Three track types are compared using the vibro-acoustic model: an existing slab track with embedded UIC54 rails, a newly designed, acoustically optimized slab track with a less stiff rail embedded in a stiffer elastomere, and, as a reference, a ballasted track. The models of the existing tracks have been validated with measurements. Calculations indicate that the optimized slab track will emit between 4 and 6 dB(A) less noise than the ballasted track. The existing slab track produces between 1·5 and 3 dB(A) more noise than the ballasted track; this is caused by resonances in the elastomeric moulding material in the frequency range determining the dB(A)-level.

  1. Vibro-Acoustic Numerical Analysis for the Chain Cover of a Car Engine

    Directory of Open Access Journals (Sweden)

    Enrico Armentani

    2017-06-01

    Full Text Available In this work, a vibro-acoustic numerical and experimental analysis was carried out for the chain cover of a low powered four-cylinder four-stroke diesel engine, belonging to the FPT (FCA Power Train family called SDE (Small Diesel Engine. By applying a methodology used in the acoustic optimization of new FPT engine components, firstly a finite element model (FEM of the engine was defined, then a vibration analysis was performed for the whole engine (modal analysis, and finally a forced response analysis was developed for the only chain cover (separated from the overall engine. The boundary conditions applied to the chain cover were the accelerations experimentally measured by accelerometers located at the points of connection among chain cover, head cover, and crankcase. Subsequently, a boundary element (BE model of the only chain cover was realized to determine the chain cover noise emission, starting from the previously calculated structural vibrations. The numerical vibro-acoustic outcomes were compared with those experimentally observed, obtaining a good correlation. All the information thus obtained allowed the identification of those critical areas, in terms of noise generation, in which to undertake necessary improvements.

  2. Vibro-Acoustic Modulation Based Damage Identification in a Composite Skin-Stiffener Structure

    Science.gov (United States)

    Ooijevaar, T. H.; Loendersloot, R.; Rogge, M. D.; Akkerman, R.; Tinga, T.

    2014-01-01

    The vibro-acoustic modulation method is applied to a composite skin-stiffener structure to investigate the possibilities to utilize this method for damage identification in terms of detection, localisation and damage quantification. The research comprises a theoretical part and an experimental part. An impact load is applied to the skin-stiffener structure, resulting in a delamination underneath the stiffener. The structure is interrogated with a low frequency pump excitation and a high frequency carrier excitation. The analysis of the response in a frequency band around the carrier frequency is employed to assess the damage identification capabilities and to gain a better understanding of the modulations occurring and the underlying physical phenomena. Though vibro-acoustic is shown to be a sensitive method for damage identification, the complexity of the damage, combined with a high modal density, complicate the understanding of the relation between the physical phenomena and the modulations occurring. more research is recommended to reveal the physics behind the observations.

  3. Active vibration and noise control of vibro-acoustic system by using PID controller

    Science.gov (United States)

    Li, Yunlong; Wang, Xiaojun; Huang, Ren; Qiu, Zhiping

    2015-07-01

    Active control simulation of the acoustic and vibration response of a vibro-acoustic cavity of an airplane based on a PID controller is presented. A full numerical vibro-acoustic model is developed by using an Eulerian model, which is a coupled model based on the finite element formulation. The reduced order model, which is used to design the closed-loop control system, is obtained by the combination of modal expansion and variable substitution. Some physical experiments are made to validate and update the full-order and the reduced-order numerical models. Optimization of the actuator placement is employed in order to get an effective closed-loop control system. For the controller design, an iterative method is used to determine the optimal parameters of the PID controller. The process is illustrated by the design of an active noise and vibration control system for a cavity structure. The numerical and experimental results show that a PID-based active control system can effectively suppress the noise inside the cavity using a sound pressure signal as the controller input. It is also possible to control the noise by suppressing the vibration of the structure using the structural displacement signal as the controller input. For an airplane cavity structure, considering the issue of space-saving, the latter is more suitable.

  4. Modeling of micro-perforated panels in a complex vibro-acoustic environment using patch transfer function approach.

    Science.gov (United States)

    Maxit, L; Yang, C; Cheng, L; Guyader, J-L

    2012-03-01

    A micro-perforated panel (MPP) with a backing cavity is a well known device for efficient noise absorption. This configuration has been thoroughly studied in the experimental conditions of an acoustic tube (Kundt tube), in which the MPP is excited by a normal incident plane wave in one dimension. In a more practical situation, the efficiency of MPP may be influenced by the vibro-acoustic behavior of the surrounding systems as well as excitation. To deal with this problem, a vibro-acoustic formulation based on the patch transfer functions (PTF) approach is proposed to model the behavior of a micro-perforated structure in a complex vibro-acoustic environment. PTF is a substructuring approach, which allows assembling different vibro-acoustic subsystems through coupled surfaces. Upon casting micro-perforations and the flexibility of the MPP under transfer function framework, the proposed PTF formulation provides explicit representation of the coupling between subsystems and facilitates physical interpretation. As an illustration example, application to a MPP with a backing cavity located in an infinite baffle is demonstrated. The proposed PTF formulation is finally validated through comparison with experimental measurements available in the literature. © 2012 Acoustical Society of America

  5. Virtual Sensor Test Instrumentation

    Science.gov (United States)

    Wang, Roy

    2011-01-01

    Virtual Sensor Test Instrumentation is based on the concept of smart sensor technology for testing with intelligence needed to perform sell-diagnosis of health, and to participate in a hierarchy of health determination at sensor, process, and system levels. A virtual sensor test instrumentation consists of five elements: (1) a common sensor interface, (2) microprocessor, (3) wireless interface, (4) signal conditioning and ADC/DAC (analog-to-digital conversion/ digital-to-analog conversion), and (5) onboard EEPROM (electrically erasable programmable read-only memory) for metadata storage and executable software to create powerful, scalable, reconfigurable, and reliable embedded and distributed test instruments. In order to maximize the efficient data conversion through the smart sensor node, plug-and-play functionality is required to interface with traditional sensors to enhance their identity and capabilities for data processing and communications. Virtual sensor test instrumentation can be accessible wirelessly via a Network Capable Application Processor (NCAP) or a Smart Transducer Interlace Module (STIM) that may be managed under real-time rule engines for mission-critical applications. The transducer senses the physical quantity being measured and converts it into an electrical signal. The signal is fed to an A/D converter, and is ready for use by the processor to execute functional transformation based on the sensor characteristics stored in a Transducer Electronic Data Sheet (TEDS). Virtual sensor test instrumentation is built upon an open-system architecture with standardized protocol modules/stacks to interface with industry standards and commonly used software. One major benefit for deploying the virtual sensor test instrumentation is the ability, through a plug-and-play common interface, to convert raw sensor data in either analog or digital form, to an IEEE 1451 standard-based smart sensor, which has instructions to program sensors for a wide variety of

  6. Vibro-acoustic characterization of flexible hose in CO2 car air conditioning systems

    Science.gov (United States)

    Angelini, F.; Bergami, A.; Martarelli, M.; Tomasini, E. P.

    2008-06-01

    Following the EU directive 2006/40/EC proscribing from 2011 that refrigerant fluids must have a global warming potential not higher than 150, it will not be allowed anymore to employ the current R134a on car air conditioning systems. Maflow s.p.a (automotive hose maker) is developing products for each possible new refrigerant. This paper is focused on hoses for CO2 refrigerants operating in the worst conditions because of the high pressures and temperatures at which they are working (with R134a the high pressure is 18 bar and low pressure is 3 bar; with CO2 the high pressure is 100 bar and low pressure is 35 bar). Therefore the noise emission control of the CO2 air conditioning systems is very important. The aim of this study is to develop a standard measurement method for the vibro - acoustic characterization of High Pressure (HP - Shark F4) and Low Pressure (LP - ULEV) hoses to reduce noise emission and raise car passenger comfort; in particular deep research on high pressure hose. The method is based on the measurement of the vibration level of the hoses in a standard test bench by means of a Laser Doppler Vibrometer (LDV) and its acoustic emission by a sound intensity probe.

  7. Modeling of micro-perforated panels in a complex vibro-acoustic environment using patch transfer function approach

    OpenAIRE

    Maxit, Laurent; C. Yang; Cheng, Li; Guyader, Jean-Louis

    2012-01-01

    International audience; The micro-perforated panel (MPP) with a backing cavity is a well known efficient device for noise absorption. This device has been thoroughly studied in the experimental conditions of an acoustic tube (Kundt tube), in which the MPP is excited by a normal incident plane wave in one dimension. In an industrial situation, the efficiency of MPP may be influenced by the vibro-acoustic behaviour of the surrounding systems as well as excitation. To deal with this problem, a v...

  8. Comparison of Estimation Techniques for Vibro-Acoustic Transfer Path Analysis

    Directory of Open Access Journals (Sweden)

    Paulo Eduardo França Padilha

    2006-01-01

    Full Text Available Vibro-acoustic Transfer Path Analysis (TPA is a tool to evaluate the contribution of different energy propagation paths between a source and a receiver, linked to each other by a number of connections. TPA is typically used to quantify and rank the relative importance of these paths in a given frequency band, determining the most significant one to the receiver. Basically, two quantities have to be determined for TPA: the operational forces at each transfer path and the Frequency Response Functions (FRF of these paths. The FRF are obtained either experimentally or analytically, and the influence of the mechanical impedance of the source can be taken into account or not. The operational forces can be directly obtained from measurements using force transducers or indirectly estimated from auxiliary response measurements. Two methods to obtain the operational forces indirectly – the Complex Stiffness Method (CSM and the Matrix Inversion Method (MIM – associated with two possible configurations to determine the FRF – including and excluding the source impedance – are presented and discussed in this paper. The effect of weak and strong coupling among the paths is also commented considering the techniques previously presented. The main conclusion is that, with the source removed, CSM gives more accurate results. On the other hand, with the source present, MIM is preferable. In the latter case, CSM should be used only if there is a high impedance mismatch between the source and the receiver. Both methods are not affected by a higher or lower degree of coupling among the transfer paths.

  9. Vibro-Acoustic Analysis of Computer Disk Drive Components with Emphasis on Electro-Mechanical Noise Sources.

    Science.gov (United States)

    Lee, Ming-Ran

    Vibro-acoustic characteristics of compact electro -mechanical devices are not well understood. This study examines fundamental research issues in this area through the example case of a 3.5" personal computer hard disk drive. In particular, a narrow band mathematical model of the drive has been developed to predict prominent pure tones over the high frequency range (1-6.5 KHz). Through detailed analytical studies, it has been found that the motor torque pulsation of the brushless d.c. motor is the source for this noise problem. Accordingly, a simplified disk drive model consisting of motor driving a single disk is used to investigate key components, with emphasis on the development of new mathematical models to describe the source, path and radiator characteristics. Two different mathematical models have been developed for brushless d.c. motor to predict the torque spectrum associated with invertor switching logic, pulse width modulation control scheme, eccentricity, and magnetic saturation. Frequency contents of predicted variables are identified and matched with measured sound data. Additionally, the Galerkin's method (or modified harmonic balance) is also employed successfully to develop an efficient computational scheme which predicts the Fourier coefficients of torque pulsations directly including various effects associated with inductance harmonics and the fluctuation of rotor angular velocity. For the radiator (annular disk), modal base formulations of sound radiation have been developed by approximating disk eigen-functions. Specifically, the effects of modal coupling and source rotation on radiated sound are investigated. Analytical predictions match well with numerical results obtained by using a boundary element program. New mobility transfer functions (path) are derived to couple the source and radiator formulations in order to construct an overall vibro-acoustic model. Potential areas of further research including experimental validation are discussed.

  10. Implementation of a self-sensing piezoelectric actuator for vibro-acoustic active control

    Science.gov (United States)

    Pelletier, Anik; Micheau, Philippe; Berry, Alain

    2014-04-01

    Significant reduction of airplane interior noise may be obtained by active structural acoustic control (ASAC) of fuselage panels. This requires to accurately measure the vibrations of the aircraft panels while injecting anti-vibrations. Co-located piezoelectric sensors and actuators, spatially distributed on the structure, are an interesting avenue since they can lead to the implementation of distributed virtual impedances. When the same piezoelectric device is used to simultaneously measure and actuate, it is called a self-sensing piezoelectric actuator (SSPA). When a SSPA is submitted to a voltage, the measured current is the sum of the electric current due to the capacitive effect of the transducer plus the mechanical current induced by the strain of the structure. The latter is an order of magnitude smaller than the total current measured. Provided the measured current is digitized with sufficient accuracy, adequate numerical processing can subtract the capacitive current from the total measured current. A similar processing can also be used to subtract from the sensor information, near-field vibrations induced by the collocated actuator. Hence, information related to the global, vibrational flexural modes of the plate is extracted without complicated electronics. The numerical method of current separation has been programmed and validated with MATLAB/SimulinkR® and implemented on Speedgoat hardware. A shunt resistor is used to measure the current simultaneously with the voltage measurement. Strain-induced current has been successfully extracted from SSPA signal with this method. Numerical simulations show good agreement with experimental data.

  11. Virtual Sensor Test Instrumentation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Mobitrum has started the development of virtual sensor test instrumentation in Phase I for characterization and measurement of ground testing of propulsion systems....

  12. A hybrid approach for predicting the distribution of vibro-acoustic energy in complex built-up structures.

    Science.gov (United States)

    Maksimov, Dmitrii N; Tanner, Gregor

    2011-09-01

    Finding the distribution of vibro-acoustic energy in complex built-up structures in the mid-to-high frequency regime is a difficult task. In particular, structures with large variation of local wavelengths and/or characteristic scales pose a challenge referred to as the mid-frequency problem. Standard numerical methods such as the finite element method (FEM) scale with the local wavelength and quickly become too large even for modern computer architectures. High frequency techniques, such as statistical energy analysis (SEA), often miss important information such as dominant resonance behavior due to stiff or small scale parts of the structure. Hybrid methods circumvent this problem by coupling FEM/BEM and SEA models in a given built-up structure. In the approach adopted here, the whole system is split into a number of subsystems that are treated by either FEM or SEA depending on the local wavelength. Subsystems with relative long wavelengths are modeled using FEM. Making a diffuse field assumption for the wave fields in the short wave length components, the coupling between subsystems can be reduced to a weighted random field correlation function. The approach presented results in an SEA-like set of linear equations that can be solved for the mean energies in the short wavelength subsystems. © 2011 Acoustical Society of America

  13. Development of Fetal Movement between 26 and 36 Weeks’ Gestation in Response to Vibro-acoustic Stimulation

    Directory of Open Access Journals (Sweden)

    Marybeth eGrant-Beuttler

    2011-12-01

    Full Text Available Background: Ultrasound observation of fetal movement has documented general trends in motor development and fetal age when motor response to stimulation is observed. Evaluation of fetal movement quality, in addition to specific motor activity, may improve documentation of motor development and highlight specific motor responses to stimulation. Aims: The aim of this investigation was to assess fetal movement at 26 and 36 weeks gestation during three conditions (baseline, immediate response to vibro-acoustic stimulation (VAS, and post-response. Design: A prospective, longitudinal design was utilized. Subjects: Twelve normally developing fetuses, 8 females and 4 males, were examined with continuous ultrasound imaging. Outcome measures: The Fetal Neurobehavioral Coding System (FENS was used to evaluate the quality of motor activity during 10-second epochs over the three conditions. Results: Seventy-five percent of the fetuses at the 26 week assessment and 100% of the fetuses at the 36 week assessment responded with movement immediately following stimulation. Significant differences in head, fetal breathing, general, limb, and mouthing movements were detected between the 26 week and 36 week assessments. Movement differences between conditions were detected in head, fetal breathing, limb, and mouthing movements. Conclusions: Smoother and more complex movement was observed with fetal maturation. Following VAS stimulation, an immediate increase of large, jerky movements suggest instability in fetal capabilities. Fetal movement quality changes over gestation may reflect sensorimotor synaptogenesis in the central nervous system, while observation of immature movement patterns following VAS stimulation may reflect movement pattern instability.

  14. SmEdA vibro-acoustic modelling in the mid-frequency range including the effect of dissipative treatments

    Science.gov (United States)

    Hwang, H. D.; Maxit, L.; Ege, K.; Gerges, Y.; Guyader, J.-L.

    2017-04-01

    Vibro-acoustic simulation in the mid-frequency range is of interest for automotive and truck constructors. The dissipative treatments used for noise and vibration control such as viscoelastic patches and acoustic absorbing materials must be taken into account in the problem. The Statistical modal Energy distribution Analysis (SmEdA) model consists in extending Statistical Energy Analysis (SEA) to the mid-frequency range by establishing power balance equations between the modes of the different subsystems. The modal basis of uncoupled-subsystems that can be estimated by the finite element method in the mid-frequency range is used as input data. SmEdA was originally developed by considering constant modal damping factors for each subsystem. However, this means that it cannot describe the local distribution of dissipative materials. To overcome this issue, a methodology is proposed here to take into account the effect of these materials. This methodology is based on the finite element models of the subsystems that include well-known homogenized material models of dissipative treatments. The Galerkin method with subsystem normal modes is used to estimate the modal damping loss factors. Cross-modal coupling terms which appear in the formulation due to the dissipative materials are assumed to be negligible. An approximation of the energy sharing between the subsystems damped by dissipative materials is then described by SmEdA. The different steps of the method are validated experimentally by applying it to a laboratory test case composed of a plate-cavity system with different configurations of dissipative treatments. The comparison between the experimental and the simulation results shows good agreement in the mid-frequency range.

  15. Vibro-Acoustic Response Analysis Of LAUNCH VEHICLE INTER-STAGE

    Directory of Open Access Journals (Sweden)

    Anjana Mariam Alex

    2015-08-01

    Full Text Available Right from lift-off launch vehicles are subjected to extreme dynamic pressure aero and structure borne excitations. Inter-stage is fundamental to the vehicle as it houses the different control equipments actuators sensors motors and avionic packages. This paper involves the creation of two different models so as to study the correlation using two approaches Finite Element method and Hybrid Method involving Statistical Energy Analysis and Finite Element Analysis. The correlation of the response obtained on the Inter-stage from an acoustic ground test to that from the analytical test results carried out with VA One is also addressed in this paper.

  16. Virtual Sensor Test Instrumentation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Smart sensor combining with embedded metadata and wireless technology presents real opportunities for significant improvements in reliability, cost-benefits, and...

  17. Virtual Lab for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    PICOVICI, D.

    2008-06-01

    Full Text Available This article details an experimental system developed to enhance the education and research in the area of wireless networks technologies. The system referred, as Virtual Lab (VL is primarily targeting first time users or users with limited experience in programming and using wireless sensor networks. The VL enables a set of predefined sensor networks to be remotely accessible and controlled for constructive and time-efficient experimentation. In order to facilitate the user's wireless sensor applications, the VL is using three main components: a a Virtual Lab Motes (VLM, representing the wireless sensor, b a Virtual Lab Client (VLC, representing the user's tool to interact with the VLM and c a Virtual Lab Server (VLS representing the software link between the VLM and VLC. The concept has been proven using the moteiv produced Tmote Sky modules. Initial experimental use clearly demonstrates that the VL approach reduces dramatically the learning curve involved in programming and using the associated wireless sensor nodes. In addition the VL allows the user's focus to be directed towards the experiment and not towards the software programming challenges.

  18. Vibro-acoustic modeling and analysis of a coupled acoustic system comprising a partially opened cavity coupled with a flexible plate

    Science.gov (United States)

    Shi, Shuangxia; Su, Zhu; Jin, Guoyong; Liu, Zhigang

    2018-01-01

    This paper is concerned with the modeling and solution method of a three-dimensional (3D) coupled acoustic system comprising a partially opened cavity coupled with a flexible plate and an exterior field of semi-infinite size, which is ubiquitously encountered in architectural acoustics and is a reasonable representation of many engineering occasions. A general solution method is presented to predict the dynamic behaviors of the three-dimensional (3D) acoustic coupled system, in which the displacement of the plate and the sound pressure in the cavity are respectively constructed in the form of the two-dimensional and three-dimensional modified Fourier series with several auxiliary functions introduced to ensure the uniform convergence of the solution over the entire solution domain. The effect of the opening is taken into account via the work done by the sound pressure acting at the coupling aperture that is contributed from the vibration of particles on the acoustic coupling interface and on the structural-acoustic coupling interface. Both the acoustic coupling between finite cavity and exterior field and the structural-acoustic coupling between flexible plate and interior acoustic field are considered in the vibro-acoustic modeling of the three-dimensional acoustic coupled acoustic system. The dynamic responses of the coupled structural-acoustic system are obtained using the Rayleigh-Ritz procedure based on the energy expressions for the coupled system. The accuracy and effectiveness of the proposed method are validated through numerical examples and comparison with results obtained by the boundary element analysis. Furthermore, the influence of the opening and the cavity volume on the acoustic behaviors of opened cavity system is studied.

  19. VLSI Design of Trusted Virtual Sensors

    Directory of Open Access Journals (Sweden)

    Macarena C. Martínez-Rodríguez

    2018-01-01

    Full Text Available This work presents a Very Large Scale Integration (VLSI design of trusted virtual sensors providing a minimum unitary cost and very good figures of size, speed and power consumption. The sensed variable is estimated by a virtual sensor based on a configurable and programmable PieceWise-Affine hyper-Rectangular (PWAR model. An algorithm is presented to find the best values of the programmable parameters given a set of (empirical or simulated input-output data. The VLSI design of the trusted virtual sensor uses the fast authenticated encryption algorithm, AEGIS, to ensure the integrity of the provided virtual measurement and to encrypt it, and a Physical Unclonable Function (PUF based on a Static Random Access Memory (SRAM to ensure the integrity of the sensor itself. Implementation results of a prototype designed in a 90-nm Complementary Metal Oxide Semiconductor (CMOS technology show that the active silicon area of the trusted virtual sensor is 0.86 mm 2 and its power consumption when trusted sensing at 50 MHz is 7.12 mW. The maximum operation frequency is 85 MHz, which allows response times lower than 0.25 μ s. As application example, the designed prototype was programmed to estimate the yaw rate in a vehicle, obtaining root mean square errors lower than 1.1%. Experimental results of the employed PUF show the robustness of the trusted sensing against aging and variations of the operation conditions, namely, temperature and power supply voltage (final value as well as ramp-up time.

  20. Control Reconfiguration of LPV Systems Using Virtual Sensor and Virtual Actuator

    DEFF Research Database (Denmark)

    Tabatabaeipour, Seyed Mojtaba; Stoustrup, Jakob; Bak, Thomas

    2012-01-01

    In this paper, a fault tolerant control method for linear parameter varying (LPV) systems using a virtual actuator and a virtual sensor is proposed. The basic idea of the method is to insert a reconfiguration block, which consists of an LPV virtual actuator and an LPV virtual sensor, between the ...

  1. Analysis of Virtual Sensors for Predicting Aircraft Fuel Consumption

    Data.gov (United States)

    National Aeronautics and Space Administration — Previous research described the use of machine learning algorithms to predict aircraft fuel consumption. This technique, known as Virtual Sensors, models fuel...

  2. Modificações da hemodinâmica fetal pelo estímulo sonoro: avaliação pela dopplervelocimetria colorida Vibro-acoustic stimulation induced hemodynamic fetal changes assessed by color doppler

    Directory of Open Access Journals (Sweden)

    Francisco Mauad Filho

    1999-04-01

    Full Text Available Objetivos: verificar se ocorrem ou não alterações hemodinâmicas na aréria cerebral média (ACM aferido pela dopplervelocimetria colorida após realização de um estímulo sonoro. Métodos: trinta fetos de gestantes consideradas clinicamente normais com idade gestacional igual ou superior a 28 semanas foram submetidos a um estímulo sonoro. Examinamos as alterações da velocidade sangüínea na ACM fetal por meio do índice de resistência e da freqüência cardíaca fetal, pelo doppler colorido, antes e depois do estímulo acústico. Resultados: a média da freqüência cardíaca fetal (FCF antes do estímulo sonoro foi de 142,41 batimentos por minuto (bpm com desvio padrão de 9,01 e faixa de variação de 122 a 162 bpm. Após o estímulo sonoro, a média da FCF foi de 159,44 bpm com desvio padrão de 15,49, com faixa de variação de 130 a 187 bpm (pPurpose: to determine the possible occurrence of hemodynamic changes in the middle cerebral artery of the fetus (MCA using color doppler after vibro-acoustic stimulation. Methods: thirty fetuses from pregnant women considered to be clinically normal, with a gestational age of 28 weeks or more were submitted to vibro-acoustic stimulation. We examined the changes in blood flow rate in the middle cerebral artery of the fetus on the basis of resistance index (RI and fetal heart rate (FHR by color doppler before and after the sound stimulus. Results: mean FHR before vibro-acoustic stimulation was 142.41 beats per minute (bpm with a standard deviation of 9.01 and a range of 122 to 162 bpm. After stimulation, mean FHR was 159.44 bpm with a standard deviation of 15.49 and a range of 130 to 187 bpm (p<0.01. Mean RI in the MCA of the fetuses was 75.89% (range: 64 to 91% before the experiment. After the vibro-acoustic stimulation, mean RI was 66.93% (range: 47 to 83%; p < 0.01. Conclusions: we observed that a sound stimulus provokes the well-known immediate and significant elevation of FHR and a

  3. A Survey of Middleware for Sensor and Network Virtualization

    Directory of Open Access Journals (Sweden)

    Zubair Khalid

    2014-12-01

    Full Text Available Wireless Sensor Network (WSN is leading to a new paradigm of Internet of Everything (IoE. WSNs have a wide range of applications but are usually deployed in a particular application. However, the future of WSNs lies in the aggregation and allocation of resources, serving diverse applications. WSN virtualization by the middleware is an emerging concept that enables aggregation of multiple independent heterogeneous devices, networks, radios and software platforms; and enhancing application development. WSN virtualization, middleware can further be categorized into sensor virtualization and network virtualization. Middleware for WSN virtualization poses several challenges like efficient decoupling of networks, devices and software. In this paper efforts have been put forward to bring an overview of the previous and current middleware designs for WSN virtualization, the design goals, software architectures, abstracted services, testbeds and programming techniques. Furthermore, the paper also presents the proposed model, challenges and future opportunities for further research in the middleware designs for WSN virtualization.

  4. A survey of middleware for sensor and network virtualization.

    Science.gov (United States)

    Khalid, Zubair; Fisal, Norsheila; Rozaini, Mohd

    2014-12-12

    Wireless Sensor Network (WSN) is leading to a new paradigm of Internet of Everything (IoE). WSNs have a wide range of applications but are usually deployed in a particular application. However, the future of WSNs lies in the aggregation and allocation of resources, serving diverse applications. WSN virtualization by the middleware is an emerging concept that enables aggregation of multiple independent heterogeneous devices, networks, radios and software platforms; and enhancing application development. WSN virtualization, middleware can further be categorized into sensor virtualization and network virtualization. Middleware for WSN virtualization poses several challenges like efficient decoupling of networks, devices and software. In this paper efforts have been put forward to bring an overview of the previous and current middleware designs for WSN virtualization, the design goals, software architectures, abstracted services, testbeds and programming techniques. Furthermore, the paper also presents the proposed model, challenges and future opportunities for further research in the middleware designs for WSN virtualization.

  5. Virtual View Image over Wireless Visual Sensor Network

    Directory of Open Access Journals (Sweden)

    Gamantyo Hendrantoro

    2011-12-01

    Full Text Available In general, visual sensors are applied to build virtual view images. When number of visual sensors increases then quantity and quality of the information improves. However, the view images generation is a challenging task in Wireless Visual Sensor Network environment due to energy restriction, computation complexity, and bandwidth limitation. Hence this paper presents a new method of virtual view images generation from selected cameras on Wireless Visual Sensor Network. The aim of the paper is to meet bandwidth and energy limitations without reducing information quality. The experiment results showed that this method could minimize number of transmitted imageries with sufficient information.

  6. Virtual sensors for designing irrigation controllers in greenhouses.

    Science.gov (United States)

    Sánchez, Jorge Antonio; Rodríguez, Francisco; Guzmán, José Luis; Arahal, Manuel R

    2012-11-08

    Monitoring the greenhouse transpiration for control purposes is currently a difficult task. The absence of affordable sensors that provide continuous transpiration measurements motivates the use of estimators. In the case of tomato crops, the availability of estimators allows the design of automatic fertirrigation (irrigation + fertilization) schemes in greenhouses, minimizing the dispensed water while fulfilling crop needs. This paper shows how system identification techniques can be applied to obtain nonlinear virtual sensors for estimating transpiration. The greenhouse used for this study is equipped with a microlysimeter, which allows one to continuously sample the transpiration values. While the microlysimeter is an advantageous piece of equipment for research, it is also expensive and requires maintenance. This paper presents the design and development of a virtual sensor to model the crop transpiration, hence avoiding the use of this kind of expensive sensor. The resulting virtual sensor is obtained by dynamical system identification techniques based on regressors taken from variables typically found in a greenhouse, such as global radiation and vapor pressure deficit. The virtual sensor is thus based on empirical data. In this paper, some effort has been made to eliminate some problems associated with grey-box models: advance phenomenon and overestimation. The results are tested with real data and compared with other approaches. Better results are obtained with the use of nonlinear Black-box virtual sensors. This sensor is based on global radiation and vapor pressure deficit (VPD) measurements. Predictive results for the three models are developed for comparative purposes.

  7. Virtual Sensors for Designing Irrigation Controllers in Greenhouses

    Directory of Open Access Journals (Sweden)

    Manuel R. Arahal

    2012-11-01

    Full Text Available Monitoring the greenhouse transpiration for control purposes is currently a difficult task. The absence of affordable sensors that provide continuous transpiration measurements motivates the use of estimators. In the case of tomato crops, the availability of estimators allows the design of automatic fertirrigation (irrigation + fertilization schemes in greenhouses, minimizing the dispensed water while fulfilling crop needs. This paper shows how system identification techniques can be applied to obtain nonlinear virtual sensors for estimating transpiration. The greenhouse used for this study is equipped with a microlysimeter, which allows one to continuously sample the transpiration values. While the microlysimeter is an advantageous piece of equipment for research, it is also expensive and requires maintenance. This paper presents the design and development of a virtual sensor to model the crop transpiration, hence avoiding the use of this kind of expensive sensor. The resulting virtual sensor is obtained by dynamical system identification techniques based on regressors taken from variables typically found in a greenhouse, such as global radiation and vapor pressure deficit. The virtual sensor is thus based on empirical data. In this paper, some effort has been made to eliminate some problems associated with grey-box models: advance phenomenon and overestimation. The results are tested with real data and compared with other approaches. Better results are obtained with the use of nonlinear Black-box virtual sensors. This sensor is based on global radiation and vapor pressure deficit (VPD measurements. Predictive results for the three models are developed for comparative purposes.

  8. A Survey on Virtualization of Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Ga-Won Lee

    2012-02-01

    Full Text Available Wireless Sensor Networks (WSNs are gaining tremendous importance thanks to their broad range of commercial applications such as in smart home automation, health-care and industrial automation. In these applications multi-vendor and heterogeneous sensor nodes are deployed. Due to strict administrative control over the specific WSN domains, communication barriers, conflicting goals and the economic interests of different WSN sensor node vendors, it is difficult to introduce a large scale federated WSN. By allowing heterogeneous sensor nodes in WSNs to coexist on a shared physical sensor substrate, virtualization in sensor network may provide flexibility, cost effective solutions, promote diversity, ensure security and increase manageability. This paper surveys the novel approach of using the large scale federated WSN resources in a sensor virtualization environment. Our focus in this paper is to introduce a few design goals, the challenges and opportunities of research in the field of sensor network virtualization as well as to illustrate a current status of research in this field. This paper also presents a wide array of state-of-the art projects related to sensor network virtualization.

  9. A survey on virtualization of Wireless Sensor Networks.

    Science.gov (United States)

    Islam, Md Motaharul; Hassan, Mohammad Mehedi; Lee, Ga-Won; Huh, Eui-Nam

    2012-01-01

    Wireless Sensor Networks (WSNs) are gaining tremendous importance thanks to their broad range of commercial applications such as in smart home automation, health-care and industrial automation. In these applications multi-vendor and heterogeneous sensor nodes are deployed. Due to strict administrative control over the specific WSN domains, communication barriers, conflicting goals and the economic interests of different WSN sensor node vendors, it is difficult to introduce a large scale federated WSN. By allowing heterogeneous sensor nodes in WSNs to coexist on a shared physical sensor substrate, virtualization in sensor network may provide flexibility, cost effective solutions, promote diversity, ensure security and increase manageability. This paper surveys the novel approach of using the large scale federated WSN resources in a sensor virtualization environment. Our focus in this paper is to introduce a few design goals, the challenges and opportunities of research in the field of sensor network virtualization as well as to illustrate a current status of research in this field. This paper also presents a wide array of state-of-the art projects related to sensor network virtualization.

  10. Solid Modelling Interaction with Sensors for Virtual Reality Welding

    Directory of Open Access Journals (Sweden)

    Bharath V. G.

    2018-01-01

    Full Text Available The imperative part of strong displaying in virtual reality framework is to improve the movement of a user with definitive movement control in genuine intelligent condition. In a real environment motion characteristic is based on sensors and servomechanisms where as in virtual reality systems the motion fundamentals are kinematic in nature. To achieve physically correct interactivity suitable dynamic constraints, should be imposed which can be obtained by augmented reality interface. Beyond input and output hardware, the underlying software plays a very important role in virtual reality systems. It is responsible for the managing of input/output devices, analysing incoming data and generating proper feedback. This research paper focusses on movement displaying for connection between CAD models and Virtual Reality Models using 3ds Max 2017 and Unity 3d softwares. The paper portrays different equipment arrangement of sensors and Arduino for virtual reality welding.

  11. Monitoring and Control Interface Based on Virtual Sensors

    OpenAIRE

    Escobar, Ricardo F.; Manuel Adam-Medina; Carlos D. García-Beltrán; Víctor H. Olivares-Peregrino; David Juárez-Romero; Gerardo V. Guerrero-Ramírez

    2014-01-01

    In this article, a toolbox based on a monitoring and control interface (MCI) is presented and applied in a heat exchanger. The MCI was programed in order to realize sensor fault detection and isolation and fault tolerance using virtual sensors. The virtual sensors were designed from model-based high-gain observers. To develop the control task, different kinds of control laws were included in the monitoring and control interface. These control laws are PID, MPC and a non-linear model-based con...

  12. Vehicle Yaw Rate Estimation Using a Virtual Sensor

    Directory of Open Access Journals (Sweden)

    Mümin Tolga Emirler

    2013-01-01

    Full Text Available Road vehicle yaw stability control systems like electronic stability program (ESP are important active safety systems used for maintaining lateral stability of the vehicle. Vehicle yaw rate is the key parameter that needs to be known by a yaw stability control system. In this paper, yaw rate is estimated using a virtual sensor which contains kinematic relations and a velocity-scheduled Kalman filter. Kinematic estimation is carried out using wheel speeds, dynamic tire radius, and front wheel steering angle. In addition, a velocity-scheduled Kalman filter utilizing the linearized single-track model of the road vehicle is used in the dynamic estimation part of the virtual sensor. The designed virtual sensor is successfully tested offline using a validated, high degrees of freedom, and high fidelity vehicle model and using hardware-in-the-loop simulations. Moreover, actual road testing is carried out and the estimated yaw rate from the virtual sensor is compared with the actual yaw rate obtained from the commercial yaw rate sensor to demonstrate the effectiveness of the virtual yaw rate sensor in practical use.

  13. 3D Buried Utility Location Using A Marching-Cross-Section Algorithm for Multi-Sensor Data Fusion

    Directory of Open Access Journals (Sweden)

    Qingxu Dou

    2016-11-01

    Full Text Available We address the problem of accurately locating buried utility segments by fusing data from multiple sensors using a novel Marching-Cross-Section (MCS algorithm. Five types of sensors are used in this work: Ground Penetrating Radar (GPR, Passive Magnetic Fields (PMF, Magnetic Gradiometer (MG, Low Frequency Electromagnetic Fields (LFEM and Vibro-Acoustics (VA. As part of the MCS algorithm, a novel formulation of the extended Kalman Filter (EKF is proposed for marching existing utility tracks from a scan cross-section (scs to the next one; novel rules for initializing utilities based on hypothesized detections on the first scs and for associating predicted utility tracks with hypothesized detections in the following scss are introduced. Algorithms are proposed for generating virtual scan lines based on given hypothesized detections when different sensors do not share common scan lines, or when only the coordinates of the hypothesized detections are provided without any information of the actual survey scan lines. The performance of the proposed system is evaluated with both synthetic data and real data. The experimental results in this work demonstrate that the proposed MCS algorithm can locate multiple buried utility segments simultaneously, including both straight and curved utilities, and can separate intersecting segments. By using the probabilities of a hypothesized detection being a pipe or a cable together with its 3D coordinates, the MCS algorithm is able to discriminate a pipe and a cable close to each other. The MCS algorithm can be used for both post- and on-site processing. When it is used on site, the detected tracks on the current scs can help to determine the location and direction of the next scan line. The proposed “multi-utility multi-sensor” system has no limit to the number of buried utilities or the number of sensors, and the more sensor data used, the more buried utility segments can be detected with more accurate location

  14. Sensorized Garment Augmented 3D Pervasive Virtual Reality System

    Science.gov (United States)

    Gulrez, Tauseef; Tognetti, Alessandro; de Rossi, Danilo

    Virtual reality (VR) technology has matured to a point where humans can navigate in virtual scenes; however, providing them with a comfortable fully immersive role in VR remains a challenge. Currently available sensing solutions do not provide ease of deployment, particularly in the seated position due to sensor placement restrictions over the body, and optic-sensing requires a restricted indoor environment to track body movements. Here we present a 52-sensor laden garment interfaced with VR, which offers both portability and unencumbered user movement in a VR environment. This chapter addresses the systems engineering aspects of our pervasive computing solution of the interactive sensorized 3D VR and presents the initial results and future research directions. Participants navigated in a virtual art gallery using natural body movements that were detected by their wearable sensor shirt and then mapped the signals to electrical control signals responsible for VR scene navigation. The initial results are positive, and offer many opportunities for use in computationally intelligentman-machine multimedia control.

  15. Virtual Fabrication of Silicon Nitride Based Multifunctional MEMS Pressure Sensor

    Directory of Open Access Journals (Sweden)

    Mahesh Kumar PATANKAR

    2011-04-01

    Full Text Available This paper shows how to combine absolute and differential pressure sensor on single silicon substrate for measuring the pressure in 0 – 1 MPa range. In this work, the sensor makes use a of silicon nitride square diaphragm supported by a thick silicon rim. Piezoresistors below the diaphragms are defined by the p+ etch stop technique and structured by the anisotropic etching in Wheatstone bridge configuration. In event of pressure, mechanical deformation occurs in the diaphragm and induces the stress in it which can be translated into electrical signal accordingly. This sensor shows the sensitivity of 142 mV/V.KPa. The pressure sensor has been designed, simulated and virtually fabricated using Intellisuite MEMS software tool. Simulation results shows that the good agreement with the analytical solutions.

  16. A Survey of Middleware for Sensor and Network Virtualization

    OpenAIRE

    Zubair Khalid; Norsheila Fisal; Mohd. Rozaini

    2014-01-01

    Wireless Sensor Network (WSN) is leading to a new paradigm of Internet of Everything (IoE). WSNs have a wide range of applications but are usually deployed in a particular application. However, the future of WSNs lies in the aggregation and allocation of resources, serving diverse applications. WSN virtualization by the middleware is an emerging concept that enables aggregation of multiple independent heterogeneous devices, networks, radios and software platforms; and enhancing application de...

  17. An Energy-Efficient Approach to Enhance Virtual Sensors Provisioning in Sensor Clouds Environments.

    Science.gov (United States)

    Lemos, Marcus Vinícius de S; Filho, Raimir Holanda; Rabêlo, Ricardo de Andrade L; de Carvalho, Carlos Giovanni N; Mendes, Douglas Lopes de S; Costa, Valney da Gama

    2018-02-26

    Virtual sensors provisioning is a central issue for sensors cloud middleware since it is responsible for selecting physical nodes, usually from Wireless Sensor Networks (WSN) of different owners, to handle user's queries or applications. Recent works perform provisioning by clustering sensor nodes based on the correlation measurements and then selecting as few nodes as possible to preserve WSN energy. However, such works consider only homogeneous nodes (same set of sensors). Therefore, those works are not entirely appropriate for sensor clouds, which in most cases comprises heterogeneous sensor nodes. In this paper, we propose ACxSIMv2, an approach to enhance the provisioning task by considering heterogeneous environments. Two main algorithms form ACxSIMv2. The first one, ACASIMv1, creates multi-dimensional clusters of sensor nodes, taking into account the measurements correlations instead of the physical distance between nodes like most works on literature. Then, the second algorithm, ACOSIMv2, based on an Ant Colony Optimization system, selects an optimal set of sensors nodes from to respond user's queries while attending all parameters and preserving the overall energy consumption. Results from initial experiments show that the approach reduces significantly the sensor cloud energy consumption compared to traditional works, providing a solution to be considered in sensor cloud scenarios.

  18. Sensor data storage performance: SQL or NoSQL, physical or virtual

    NARCIS (Netherlands)

    Veen, J.S. van der; Waaij, B.D. van der; Meijer, R.J.

    2012-01-01

    Sensors are used to monitor certain aspects of the physical or virtual world and databases are typically used to store the data that these sensors provide. The use of sensors is increasing, which leads to an increasing demand on sensor data storage platforms. Some sensor monitoring applications need

  19. Monitoring and control interface based on virtual sensors.

    Science.gov (United States)

    Escobar, Ricardo F; Adam-Medina, Manuel; García-Beltrán, Carlos D; Olivares-Peregrino, Víctor H; Juárez-Romero, David; Guerrero-Ramírez, Gerardo V

    2014-10-31

    In this article, a toolbox based on a monitoring and control interface (MCI) is presented and applied in a heat exchanger. The MCI was programed in order to realize sensor fault detection and isolation and fault tolerance using virtual sensors. The virtual sensors were designed from model-based high-gain observers. To develop the control task, different kinds of control laws were included in the monitoring and control interface. These control laws are PID, MPC and a non-linear model-based control law. The MCI helps to maintain the heat exchanger under operation, even if a temperature outlet sensor fault occurs; in the case of outlet temperature sensor failure, the MCI will display an alarm. The monitoring and control interface is used as a practical tool to support electronic engineering students with heat transfer and control concepts to be applied in a double-pipe heat exchanger pilot plant. The method aims to teach the students through the observation and manipulation of the main variables of the process and by the interaction with the monitoring and control interface (MCI) developed in LabVIEW©. The MCI provides the electronic engineering students with the knowledge of heat exchanger behavior, since the interface is provided with a thermodynamic model that approximates the temperatures and the physical properties of the fluid (density and heat capacity). An advantage of the interface is the easy manipulation of the actuator for an automatic or manual operation. Another advantage of the monitoring and control interface is that all algorithms can be manipulated and modified by the users.

  20. Monitoring and Control Interface Based on Virtual Sensors

    Directory of Open Access Journals (Sweden)

    Ricardo F. Escobar

    2014-10-01

    Full Text Available In this article, a toolbox based on a monitoring and control interface (MCI is presented and applied in a heat exchanger. The MCI was programed in order to realize sensor fault detection and isolation and fault tolerance using virtual sensors. The virtual sensors were designed from model-based high-gain observers. To develop the control task, different kinds of control laws were included in the monitoring and control interface. These control laws are PID, MPC and a non-linear model-based control law. The MCI helps to maintain the heat exchanger under operation, even if a temperature outlet sensor fault occurs; in the case of outlet temperature sensor failure, the MCI will display an alarm. The monitoring and control interface is used as a practical tool to support electronic engineering students with heat transfer and control concepts to be applied in a double-pipe heat exchanger pilot plant. The method aims to teach the students through the observation and manipulation of the main variables of the process and by the interaction with the monitoring and control interface (MCI developed in LabVIEW©. The MCI provides the electronic engineering students with the knowledge of heat exchanger behavior, since the interface is provided with a thermodynamic model that approximates the temperatures and the physical properties of the fluid (density and heat capacity. An advantage of the interface is the easy manipulation of the actuator for an automatic or manual operation. Another advantage of the monitoring and control interface is that all algorithms can be manipulated and modified by the users.

  1. Virtual Sensors for Biodiesel Production in a Batch Reactor

    Directory of Open Access Journals (Sweden)

    Betty Y. López-Zapata

    2017-03-01

    Full Text Available Fossil fuel combustion produces around 98% of coal emissions. Therefore, liquid and gaseous biofuels have become more attractive due to their environmental benefits. The biodiesel production process requires measurements that help to control and supervise the variables involved in the process. The measurements provide valuable information about the operation conditions and give estimations about the critical variables of the process. The information from measurements is essential for monitoring the state of a process and verifying if it has an optimal performance. The objective of this study was the conception of a virtual sensor based on the Extended Kalman Filter (EKF and the model of a batch biodiesel reactor for estimating concentrations of triglycerides (TG, diglycerides (DG, monoglycerides (MG, methyl ester (E, alcohol (A, and glycerol (GL in real-time through measurement of the temperature and pH. Estimation of the TG, DG, MG, E, A, and Gl through this method eliminates the need for additional sensors and allows the use of different types of control. For the performance analysis of the virtual sensor, the data obtained from the EKF are compared with experimental data reported in the literature, with the mean square error of the estimate then being calculated. In addition, the results of this approach can be implemented in a real system, since it only uses measurements available in a reactor such as temperature and pH.

  2. Hybrid Feedforward-Feedback Noise Control Using Virtual Sensors

    Science.gov (United States)

    Bean, Jacob; Fuller, Chris; Schiller, Noah

    2016-01-01

    Several approaches to active noise control using virtual sensors are evaluated for eventual use in an active headrest. Specifically, adaptive feedforward, feedback, and hybrid control structures are compared. Each controller incorporates the traditional filtered-x least mean squares algorithm. The feedback controller is arranged in an internal model configuration to draw comparisons with standard feedforward control theory results. Simulation and experimental results are presented that illustrate each controllers ability to minimize the pressure at both physical and virtual microphone locations. The remote microphone technique is used to obtain pressure estimates at the virtual locations. It is shown that a hybrid controller offers performance benefits over the traditional feedforward and feedback controllers. Stability issues associated with feedback and hybrid controllers are also addressed. Experimental results show that 15-20 dB reduction in broadband disturbances can be achieved by minimizing the measured pressure, whereas 10-15 dB reduction is obtained when minimizing the estimated pressure at a virtual location.

  3. Development of a Virtual Collision Sensor for Industrial Robots.

    Science.gov (United States)

    Indri, Marina; Trapani, Stefano; Lazzero, Ivan

    2017-05-18

    Collision detection is a fundamental issue for the safety of a robotic cell. While several common methods require specific sensors or the knowledge of the robot dynamic model, the proposed solution is constituted by a virtual collision sensor for industrial manipulators, which requires as inputs only the motor currents measured by the standard sensors that equip a manipulator and the estimated currents provided by an internal dynamic model of the robot (i.e., the one used inside its controller), whose structure, parameters and accuracy are not known. The collision detection is achieved by comparing the absolute value of the current residue with a time-varying, positive-valued threshold function, including an estimate of the model error and a bias term, corresponding to the minimum collision torque to be detected. The value of such a term, defining the sensor sensitivity, can be simply imposed as constant, or automatically customized for a specific robotic application through a learning phase and a subsequent adaptation process, to achieve a more robust and faster collision detection, as well as the avoidance of any false collision warnings, even in case of slow variations of the robot behavior. Experimental results are provided to confirm the validity of the proposed solution, which is already adopted in some industrial scenarios.

  4. Development of a Virtual Collision Sensor for Industrial Robots

    Directory of Open Access Journals (Sweden)

    Marina Indri

    2017-05-01

    Full Text Available Collision detection is a fundamental issue for the safety of a robotic cell. While several common methods require specific sensors or the knowledge of the robot dynamic model, the proposed solution is constituted by a virtual collision sensor for industrial manipulators, which requires as inputs only the motor currents measured by the standard sensors that equip a manipulator and the estimated currents provided by an internal dynamic model of the robot (i.e., the one used inside its controller, whose structure, parameters and accuracy are not known. The collision detection is achieved by comparing the absolute value of the current residue with a time-varying, positive-valued threshold function, including an estimate of the model error and a bias term, corresponding to the minimum collision torque to be detected. The value of such a term, defining the sensor sensitivity, can be simply imposed as constant, or automatically customized for a specific robotic application through a learning phase and a subsequent adaptation process, to achieve a more robust and faster collision detection, as well as the avoidance of any false collision warnings, even in case of slow variations of the robot behavior. Experimental results are provided to confirm the validity of the proposed solution, which is already adopted in some industrial scenarios.

  5. Monitoring power breakers using vibro acoustic techniques

    Directory of Open Access Journals (Sweden)

    Horia Balan

    2017-09-01

    Full Text Available Speaking about the commutation’s equipment, it can be said that the best solution in increasing reliability and lowering the maintenance costs is a continuous monitoring of the equipment. However, if the price/quality ratio is considered, it is obvious that, for the moment, the diagnosis can be also an acceptable solution. Nowadays the predictive maintenance for equipment’s diagnosis is currently replacing the preventive diagnosis. An efficient modality of lowering the maintenance costs is to online monitoring the power breakers, during their operation in the power systems. Consequently any connecting/disconnecting operations may be used in diagnosing a power breaker. Thus any supplementary and superfluous tests and/or maintenance maneuvers are avoided. The paper presents the operational maintenance in a power station with three high voltage active breakers, Areva type. The method of establishing the state of a breaker consists in the comparison between the signature of the acoustic signal provided by the manufacturer and the signal issued from the testing operation of the breaker’s state. The software processing procedure and the methodology of determining the faults of the monitored equipment are also developed. All the tests on the circuit breaker are made according the prescriptions of normative.

  6. Experimental Validation of a Virtual Engine-Out NOx Sensor for Diesel Emission Control

    NARCIS (Netherlands)

    Escobar Valdivieso, D.; Mentink, P.; Külah, S.; Forrai, A.; Willems, F.P.T.

    2017-01-01

    Motivated by automotive emissions legislations, a Virtual NOx sensor is developed. This virtual sensor consists of a real-time, phenomenological model that computes engine-out NOx by using the measured in-cylinder pressure signal from a single cylinder as its main input. The implementation is made

  7. Constructing Battery-Aware Virtual Backbones in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Chi Ma

    2007-05-01

    Full Text Available A critical issue in battery-powered sensor networks is to construct energy efficient virtual backbones for network routing. Recent study in battery technology reveals that batteries tend to discharge more power than needed and reimburse the over-discharged power if they are recovered. In this paper we first provide a mathematical battery model suitable for implementation in sensor networks. We then introduce the concept of battery-aware connected dominating set (BACDS and show that in general the minimum BACDS (MBACDS can achieve longer lifetime than the previous backbone structures. Then we show that finding a MBACDS is NP-hard and give a distributed approximation algorithm to construct the BACDS. The resulting BACDS constructed by our algorithm is at most (8+Δopt size, where Δ is the maximum node degree and opt is the size of an optimal BACDS. Simulation results show that the BACDS can save a significant amount of energy and achieve up to 30% longer network lifetime than previous schemes.

  8. Intelligent neonatal monitoring based on a virtual thermal sensor.

    Science.gov (United States)

    Abbas, Abbas K; Leonhardt, Steffen

    2014-03-02

    Temperature measurement is a vital part of daily neonatal care. Accurate measurements are important for detecting deviations from normal values for both optimal incubator and radiant warmer functioning. The purpose of monitoring the temperature is to maintain the infant in a thermoneutral environmental zone. This physiological zone is defined as the narrow range of environmental temperatures in which the infant maintains a normal body temperature without increasing his or her metabolic rate and thus oxygen consumption. Although the temperature measurement gold standard is the skin electrode, infrared thermography (IRT) should be considered as an effortless and reliable tool for measuring and mapping human skin temperature distribution and assist in assessing thermoregulatory reflexes. Body surface temperature was recorded under several clinical conditions using an infrared thermography imaging technique. Temperature distributions were recorded as real-time video, which was analyzed to evaluate mean skin temperatures. Emissivity variations were considered for optimal neonatal IRT correction for which the compensation vector was overlaid on the tracking algorithm to improve the temperature reading. Finally, a tracking algorithm was designed for active follow-up of the defined region of interest over a neonate's geometry. The outcomes obtained from the thermal virtual sensor demonstrate its ability to accurately track different geometric profiles and shapes over the external anatomy of a neonate. Only a small percentage of the motion detection attempts failed to fit tracking scenarios due to the lack of a properly matching matrix for the ROI profile over neonate's body surface. This paper presents the design and implementation of a virtual temperature sensing application that can assist neonatologists in interpreting a neonate's skin temperature patterns. Regarding the surface temperature, the influence of different environmental conditions inside the incubator has

  9. A Virtual Sensor for Online Fault Detection of Multitooth-Tools

    Directory of Open Access Journals (Sweden)

    Andres Bustillo

    2011-03-01

    Full Text Available The installation of suitable sensors close to the tool tip on milling centres is not possible in industrial environments. It is therefore necessary to design virtual sensors for these machines to perform online fault detection in many industrial tasks. This paper presents a virtual sensor for online fault detection of multitooth tools based on a Bayesian classifier. The device that performs this task applies mathematical models that function in conjunction with physical sensors. Only two experimental variables are collected from the milling centre that performs the machining operations: the electrical power consumption of the feed drive and the time required for machining each workpiece. The task of achieving reliable signals from a milling process is especially complex when multitooth tools are used, because each kind of cutting insert in the milling centre only works on each workpiece during a certain time window. Great effort has gone into designing a robust virtual sensor that can avoid re-calibration due to, e.g., maintenance operations. The virtual sensor developed as a result of this research is successfully validated under real conditions on a milling centre used for the mass production of automobile engine crankshafts. Recognition accuracy, calculated with a k-fold cross validation, had on average 0.957 of true positives and 0.986 of true negatives. Moreover, measured accuracy was 98%, which suggests that the virtual sensor correctly identifies new cases.

  10. A Virtual Sensor for Online Fault Detection of Multitooth-Tools

    Science.gov (United States)

    Bustillo, Andres; Correa, Maritza; Reñones, Anibal

    2011-01-01

    The installation of suitable sensors close to the tool tip on milling centres is not possible in industrial environments. It is therefore necessary to design virtual sensors for these machines to perform online fault detection in many industrial tasks. This paper presents a virtual sensor for online fault detection of multitooth tools based on a Bayesian classifier. The device that performs this task applies mathematical models that function in conjunction with physical sensors. Only two experimental variables are collected from the milling centre that performs the machining operations: the electrical power consumption of the feed drive and the time required for machining each workpiece. The task of achieving reliable signals from a milling process is especially complex when multitooth tools are used, because each kind of cutting insert in the milling centre only works on each workpiece during a certain time window. Great effort has gone into designing a robust virtual sensor that can avoid re-calibration due to, e.g., maintenance operations. The virtual sensor developed as a result of this research is successfully validated under real conditions on a milling centre used for the mass production of automobile engine crankshafts. Recognition accuracy, calculated with a k-fold cross validation, had on average 0.957 of true positives and 0.986 of true negatives. Moreover, measured accuracy was 98%, which suggests that the virtual sensor correctly identifies new cases. PMID:22163766

  11. Sensor Virtual Adaptable de Concentración de Etanol para Fermentadores Industriales

    Directory of Open Access Journals (Sweden)

    Boris Martínez

    2009-07-01

    Full Text Available Resumen: Los sistemas de control emplean sensores para observar el estado del proceso y tomar decisiones. En ocasiones, se necesita estimar las variables del proceso pues el sensor adecuado no existe, es prohibitivamente costoso o las mediciones son difíciles de realizar. Una solución consiste en inferir las variables no medidas a partir de otras variables mediante sensores virtuales o sensores por software (soft-sensors. En los procesos de fermentación alcohólica, la medición de la concentración del etanol es esencial. Sin embargo, no existen sensores baratos y confiables para medirla en línea ni existe una solución aceptada por todos del modelado de dicha variable. Además, las fermentaciones nunca son iguales pues los microorganismos son muy sensibles a pequeñas desviaciones en las variables involucradas. Por tanto, estos procesos requieren un sistema de estimación adaptable y altamente robusto. En este trabajo se presenta un sensor virtual adaptable para un proceso fermentativo de bioetanol empleando un modelo borroso evolutivo a partir de datos del proceso. Además, el modelo obtenido es compacto y presenta una estructura adecuada para su aplicación futura en estrategias de control, en aras de optimizar la productividad del proceso y disminuir los costos de producción. Palabras clave: bioetanol, procesos fermentativos, sensores virtuales o sensores software, sistemas adaptables, sistemas borrosos

  12. Artificial neural networks and neuro-fuzzy inference systems as virtual sensors for hydrogen safety prediction

    Energy Technology Data Exchange (ETDEWEB)

    Karri, Vishy; Ho, Tien [School of Engineering, University of Tasmania, GPO Box 252-65, Hobart, Tasmania 7001 (Australia); Madsen, Ole [Department of Production, Aalborg University, Fibigerstraede 16, DK-9220 Aalborg (Denmark)

    2008-06-15

    Hydrogen is increasingly investigated as an alternative fuel to petroleum products in running internal combustion engines and as powering remote area power systems using generators. The safety issues related to hydrogen gas are further exasperated by expensive instrumentation required to measure the percentage of explosive limits, flow rates and production pressure. This paper investigates the use of model based virtual sensors (rather than expensive physical sensors) in connection with hydrogen production with a Hogen 20 electrolyzer system. The virtual sensors are used to predict relevant hydrogen safety parameters, such as the percentage of lower explosive limit, hydrogen pressure and hydrogen flow rate as a function of different input conditions of power supplied (voltage and current), the feed of de-ionized water and Hogen 20 electrolyzer system parameters. The virtual sensors are developed by means of the application of various Artificial Intelligent techniques. To train and appraise the neural network models as virtual sensors, the Hogen 20 electrolyzer is instrumented with necessary sensors to gather experimental data which together with MATLAB neural networks toolbox and tailor made adaptive neuro-fuzzy inference systems (ANFIS) were used as predictive tools to estimate hydrogen safety parameters. It was shown that using the neural networks hydrogen safety parameters were predicted to less than 3% of percentage average root mean square error. The most accurate prediction was achieved by using ANFIS. (author)

  13. Adaptive Fault Detection on Liquid Propulsion Systems with Virtual Sensors: Algorithms and Architectures

    Science.gov (United States)

    Matthews, Bryan L.; Srivastava, Ashok N.

    2010-01-01

    Prior to the launch of STS-119 NASA had completed a study of an issue in the flow control valve (FCV) in the Main Propulsion System of the Space Shuttle using an adaptive learning method known as Virtual Sensors. Virtual Sensors are a class of algorithms that estimate the value of a time series given other potentially nonlinearly correlated sensor readings. In the case presented here, the Virtual Sensors algorithm is based on an ensemble learning approach and takes sensor readings and control signals as input to estimate the pressure in a subsystem of the Main Propulsion System. Our results indicate that this method can detect faults in the FCV at the time when they occur. We use the standard deviation of the predictions of the ensemble as a measure of uncertainty in the estimate. This uncertainty estimate was crucial to understanding the nature and magnitude of transient characteristics during startup of the engine. This paper overviews the Virtual Sensors algorithm and discusses results on a comprehensive set of Shuttle missions and also discusses the architecture necessary for deploying such algorithms in a real-time, closed-loop system or a human-in-the-loop monitoring system. These results were presented at a Flight Readiness Review of the Space Shuttle in early 2009.

  14. Fault-tolerant Control of Discrete-time LPV systems using Virtual Actuators and Sensors

    DEFF Research Database (Denmark)

    Tabatabaeipour, Mojtaba; Stoustrup, Jakob; Bak, Thomas

    2015-01-01

    the input-to-state stability (ISS) of the closed-loop reconfigured system. Moreover, we obtain performances in terms of the ISS gains for the virtual actuator, the virtual sensor and their interconnection. Minimizing these performances is formulated as convex optimization problems subject to LMI constraints....... Finally, the effectiveness of the method is demonstrated via a numerical example and stator current control of an induction motor....

  15. Inertial Sensor-Based Touch and Shake Metaphor for Expressive Control of 3D Virtual Avatars

    Directory of Open Access Journals (Sweden)

    Shashidhar Patil

    2015-06-01

    Full Text Available In this paper, we present an inertial sensor-based touch and shake metaphor for expressive control of a 3D virtual avatar in a virtual environment. An intuitive six degrees-of-freedom wireless inertial motion sensor is used as a gesture and motion control input device with a sensor fusion algorithm. The algorithm enables user hand motions to be tracked in 3D space via magnetic, angular rate, and gravity sensors. A quaternion-based complementary filter is implemented to reduce noise and drift. An algorithm based on dynamic time-warping is developed for efficient recognition of dynamic hand gestures with real-time automatic hand gesture segmentation. Our approach enables the recognition of gestures and estimates gesture variations for continuous interaction. We demonstrate the gesture expressivity using an interactive flexible gesture mapping interface for authoring and controlling a 3D virtual avatar and its motion by tracking user dynamic hand gestures. This synthesizes stylistic variations in a 3D virtual avatar, producing motions that are not present in the motion database using hand gesture sequences from a single inertial motion sensor.

  16. Affordable and personalized lighting using inverse modeling and virtual sensors

    Science.gov (United States)

    Basu, Chandrayee; Chen, Benjamin; Richards, Jacob; Dhinakaran, Aparna; Agogino, Alice; Martin, Rodney

    2014-03-01

    Wireless sensor networks (WSN) have great potential to enable personalized intelligent lighting systems while reducing building energy use by 50%-70%. As a result WSN systems are being increasingly integrated in state-ofart intelligent lighting systems. In the future these systems will enable participation of lighting loads as ancillary services. However, such systems can be expensive to install and lack the plug-and-play quality necessary for user-friendly commissioning. In this paper we present an integrated system of wireless sensor platforms and modeling software to enable affordable and user-friendly intelligent lighting. It requires ⇠ 60% fewer sensor deployments compared to current commercial systems. Reduction in sensor deployments has been achieved by optimally replacing the actual photo-sensors with real-time discrete predictive inverse models. Spatially sparse and clustered sub-hourly photo-sensor data captured by the WSN platforms are used to develop and validate a piece-wise linear regression of indoor light distribution. This deterministic data-driven model accounts for sky conditions and solar position. The optimal placement of photo-sensors is performed iteratively to achieve the best predictability of the light field desired for indoor lighting control. Using two weeks of daylight and artificial light training data acquired at the Sustainability Base at NASA Ames, the model was able to predict the light level at seven monitored workstations with 80%-95% accuracy. We estimate that 10% adoption of this intelligent wireless sensor system in commercial buildings could save 0.2-0.25 quads BTU of energy nationwide.

  17. Digital signal processing by virtual instrumentation of a MEMS magnetic field sensor for biomedical applications.

    Science.gov (United States)

    Juárez-Aguirre, Raúl; Domínguez-Nicolás, Saúl M; Manjarrez, Elías; Tapia, Jesús A; Figueras, Eduard; Vázquez-Leal, Héctor; Aguilera-Cortés, Luz A; Herrera-May, Agustín L

    2013-11-05

    We present a signal processing system with virtual instrumentation of a MEMS sensor to detect magnetic flux density for biomedical applications. This system consists of a magnetic field sensor, electronic components implemented on a printed circuit board (PCB), a data acquisition (DAQ) card, and a virtual instrument. It allows the development of a semi-portable prototype with the capacity to filter small electromagnetic interference signals through digital signal processing. The virtual instrument includes an algorithm to implement different configurations of infinite impulse response (IIR) filters. The PCB contains a precision instrumentation amplifier, a demodulator, a low-pass filter (LPF) and a buffer with operational amplifier. The proposed prototype is used for real-time non-invasive monitoring of magnetic flux density in the thoracic cage of rats. The response of the rat respiratory magnetogram displays a similar behavior as the rat electromyogram (EMG).

  18. Digital Signal Processing by Virtual Instrumentation of a MEMS Magnetic Field Sensor for Biomedical Applications

    Science.gov (United States)

    Juárez-Aguirre, Raúl; Domínguez-Nicolás, Saúl M.; Manjarrez, Elías; Tapia, Jesús A.; Figueras, Eduard; Vázquez-Leal, Héctor; Aguilera-Cortés, Luz A.; Herrera-May, Agustín L.

    2013-01-01

    We present a signal processing system with virtual instrumentation of a MEMS sensor to detect magnetic flux density for biomedical applications. This system consists of a magnetic field sensor, electronic components implemented on a printed circuit board (PCB), a data acquisition (DAQ) card, and a virtual instrument. It allows the development of a semi-portable prototype with the capacity to filter small electromagnetic interference signals through digital signal processing. The virtual instrument includes an algorithm to implement different configurations of infinite impulse response (IIR) filters. The PCB contains a precision instrumentation amplifier, a demodulator, a low-pass filter (LPF) and a buffer with operational amplifier. The proposed prototype is used for real-time non-invasive monitoring of magnetic flux density in the thoracic cage of rats. The response of the rat respiratory magnetogram displays a similar behavior as the rat electromyogram (EMG). PMID:24196434

  19. Remote interrogation of WDM fiber-optic intensity sensors deploying delay lines in the virtual domain.

    Science.gov (United States)

    Montero, David Sánchez; Vázquez, Carmen

    2013-05-07

    In this work a radio-frequency self-referencing WDM intensity-based fiber-optic sensor operating in reflective configuration and using virtual instrumentation is presented. The use of virtual delay lines at the reception stage, along with novel flexible self-referencing techniques, and using a single frequency, avoids all-optical or electrical-based delay lines approaches. This solution preserves the self-referencing and performance characteristics of the proposed WDM-based optical sensing topology, and leads to a more compact solution with higher flexibility for the multiple interrogation of remote sensing points in a sensor network. Results are presented for a displacement sensor demonstrating the concept feasibility.

  20. Remote Interrogation of WDM Fiber-Optic Intensity Sensors Deploying Delay Lines in the Virtual Domain

    Directory of Open Access Journals (Sweden)

    Carmen Vázquez

    2013-05-01

    Full Text Available In this work a radio-frequency self-referencing WDM intensity-based fiber-optic sensor operating in reflective configuration and using virtual instrumentation is presented. The use of virtual delay lines at the reception stage, along with novel flexible self-referencing techniques, and using a single frequency, avoids all-optical or electrical-based delay lines approaches. This solution preserves the self-referencing and performance characteristics of the proposed WDM-based optical sensing topology, and leads to a more compact solution with higher flexibility for the multiple interrogation of remote sensing points in a sensor network. Results are presented for a displacement sensor demonstrating the concept feasibility.

  1. Core body temperature control by total liquid ventilation using a virtual lung temperature sensor.

    Science.gov (United States)

    Nadeau, Mathieu; Micheau, Philippe; Robert, Raymond; Avoine, Olivier; Tissier, Renaud; Germim, Pamela Samanta; Vandamme, Jonathan; Praud, Jean-Paul; Walti, Herve

    2014-12-01

    In total liquid ventilation (TLV), the lungs are filled with a breathable liquid perfluorocarbon (PFC) while a liquid ventilator ensures proper gas exchange by renewal of a tidal volume of oxygenated and temperature-controlled PFC. Given the rapid changes in core body temperature generated by TLV using the lung has a heat exchanger, it is crucial to have accurate and reliable core body temperature monitoring and control. This study presents the design of a virtual lung temperature sensor to control core temperature. In the first step, the virtual sensor, using expired PFC to estimate lung temperature noninvasively, was validated both in vitro and in vivo. The virtual lung temperature was then used to rapidly and automatically control core temperature. Experimentations were performed using the Inolivent-5.0 liquid ventilator with a feedback controller to modulate inspired PFC temperature thereby controlling lung temperature. The in vivo experimental protocol was conducted on seven newborn lambs instrumented with temperature sensors at the femoral artery, pulmonary artery, oesophagus, right ear drum, and rectum. After stabilization in conventional mechanical ventilation, TLV was initiated with fast hypothermia induction, followed by slow posthypothermic rewarming for 1 h, then by fast rewarming to normothermia and finally a second fast hypothermia induction phase. Results showed that the virtual lung temperature was able to provide an accurate estimation of systemic arterial temperature. Results also demonstrate that TLV can precisely control core body temperature and can be favorably compared to extracorporeal circulation in terms of speed.

  2. SensorDB: a virtual laboratory for the integration, visualization and analysis of varied biological sensor data.

    Science.gov (United States)

    Salehi, Ali; Jimenez-Berni, Jose; Deery, David M; Palmer, Doug; Holland, Edward; Rozas-Larraondo, Pablo; Chapman, Scott C; Georgakopoulos, Dimitrios; Furbank, Robert T

    2015-01-01

    To our knowledge, there is no software or database solution that supports large volumes of biological time series sensor data efficiently and enables data visualization and analysis in real time. Existing solutions for managing data typically use unstructured file systems or relational databases. These systems are not designed to provide instantaneous response to user queries. Furthermore, they do not support rapid data analysis and visualization to enable interactive experiments. In large scale experiments, this behaviour slows research discovery, discourages the widespread sharing and reuse of data that could otherwise inform critical decisions in a timely manner and encourage effective collaboration between groups. In this paper we present SensorDB, a web based virtual laboratory that can manage large volumes of biological time series sensor data while supporting rapid data queries and real-time user interaction. SensorDB is sensor agnostic and uses web-based, state-of-the-art cloud and storage technologies to efficiently gather, analyse and visualize data. Collaboration and data sharing between different agencies and groups is thereby facilitated. SensorDB is available online at http://sensordb.csiro.au.

  3. MEMS Accelerometers Sensors: an Application in Virtual Reality

    Directory of Open Access Journals (Sweden)

    Daniel CORRÊA

    2010-09-01

    Full Text Available The measurement of a particular human body member position is extremely important in many applications. The human behavior understanding typically involves the body posture analysis or estimation, as well as the generated corresponding gestures. This behavior characterization allows analyzing, interpreting, and animating human actions and therefore enables us the use of experimental methodologies. Using the virtual reality devices to facilitate people’s lives, they can help to train and improve the actions of an Olympic athlete, for example and imitation of human actions by robotic systems. The systems development to monitor human body members’ movements is a growing interesting area, both in entertainment and in systems to help physically disabled people, as that developing assistive technology. To contribute to this area, this paper presents the experimental development of an instrumented glove prototype of low cost for the recognition of hand inclination movements, using a Micro-Electro-Mechanical Systems (MEMS accelerometer, by virtual reality concepts for demonstration in real time. We present the hardware that was developed, the calibration procedures, the achieved results with their statistical corresponding validation. The results allowed to state that the system is suitable for the inclination measurement in a 2D plan, thus allowing its use in entertainment systems and as an auxiliary device for assistive technology system.

  4. Virtual Deformation Control of the X-56A Model with Simulated Fiber Optic Sensors

    Science.gov (United States)

    Suh, Peter M.; Chin, Alexander W.; Mavris, Dimitri N.

    2014-01-01

    A robust control law design methodology is presented to stabilize the X-56A model and command its wing shape. The X-56A was purposely designed to experience flutter modes in its flight envelope. The methodology introduces three phases: the controller design phase, the modal filter design phase, and the reference signal design phase. A mu-optimal controller is designed and made robust to speed and parameter variations. A conversion technique is presented for generating sensor strain modes from sensor deformation mode shapes. The sensor modes are utilized for modal filtering and simulating fiber optic sensors for feedback to the controller. To generate appropriate virtual deformation reference signals, rigid-body corrections are introduced to the deformation mode shapes. After successful completion of the phases, virtual deformation control is demonstrated. The wing is deformed and it is shown that angle-ofattack changes occur which could potentially be used to an advantage. The X-56A program must demonstrate active flutter suppression. It is shown that the virtual deformation controller can achieve active flutter suppression on the X-56A simulation model.

  5. Diffusion Strategies for Distributed Kalman Filter with Dynamic Topologies in Virtualized Sensor Networks

    Directory of Open Access Journals (Sweden)

    Shujie Yang

    2016-01-01

    Full Text Available Network virtualization has become pervasive and is used in many applications. Through the combination of network virtualization and wireless sensor networks, it can greatly improve the multiple applications of traditional wireless sensor networks. However, because of the dynamic reconfiguration of topologies in the physical layer of virtualized sensor networks (VSNs, it requires a mechanism to guarantee the accuracy of estimate values by sensors. In this paper, we focus on the distributed Kalman filter algorithm with dynamic topologies to support this requirement. As one strategy of distributed Kalman filter algorithms, diffusion Kalman filter algorithm has a better performance on the state estimation. However, the existing diffusion Kalman filter algorithms all focus on the fixed topologies. Considering the dynamic topologies in the physical layer of VSNs mentioned above, we present a diffusion Kalman filter algorithm with dynamic topologies (DKFdt. Then, we emphatically derive the theoretical expressions of the mean and mean-square performance. From the expressions, the feasibility of the algorithm is verified. Finally, simulations confirm that the proposed algorithm achieves a greatly improved performance as compared with a noncooperative manner.

  6. Performance analysis of cooperative virtual MIMO systems for wireless sensor networks.

    Science.gov (United States)

    Rafique, Zimran; Seet, Boon-Chong; Al-Anbuky, Adnan

    2013-05-28

    Multi-Input Multi-Output (MIMO) techniques can be used to increase the data rate for a given bit error rate (BER) and transmission power. Due to the small form factor, energy and processing constraints of wireless sensor nodes, a cooperative Virtual MIMO as opposed to True MIMO system architecture is considered more feasible for wireless sensor network (WSN) applications. Virtual MIMO with Vertical-Bell Labs Layered Space-Time (V-BLAST) multiplexing architecture has been recently established to enhance WSN performance. In this paper, we further investigate the impact of different modulation techniques, and analyze for the first time, the performance of a cooperative Virtual MIMO system based on V-BLAST architecture with multi-carrier modulation techniques. Through analytical models and simulations using real hardware and environment settings, both communication and processing energy consumptions, BER, spectral efficiency, and total time delay of multiple cooperative nodes each with single antenna are evaluated. The results show that cooperative Virtual-MIMO with Binary Phase Shift Keying-Wavelet based Orthogonal Frequency Division Multiplexing (BPSK-WOFDM) modulation is a promising solution for future high data-rate and energy-efficient WSNs.

  7. Performance Analysis of Cooperative Virtual MIMO Systems for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Adnan Al-Anbuky

    2013-05-01

    Full Text Available Multi-Input Multi-Output (MIMO techniques can be used to increase the data rate for a given bit error rate (BER and transmission power. Due to the small form factor, energy and processing constraints of wireless sensor nodes, a cooperative Virtual MIMO as opposed to True MIMO system architecture is considered more feasible for wireless sensor network (WSN applications. Virtual MIMO with Vertical-Bell Labs Layered Space-Time (V-BLAST multiplexing architecture has been recently established to enhance WSN performance. In this paper, we further investigate the impact of different modulation techniques, and analyze for the first time, the performance of a cooperative Virtual MIMO system based on V-BLAST architecture with multi-carrier modulation techniques. Through analytical models and simulations using real hardware and environment settings, both communication and processing energy consumptions, BER, spectral efficiency, and total time delay of multiple cooperative nodes each with single antenna are evaluated. The results show that cooperative Virtual-MIMO with Binary Phase Shift Keying-Wavelet based Orthogonal Frequency Division Multiplexing (BPSK-WOFDM modulation is a promising solution for future high data-rate and energy-efficient WSNs.

  8. Virtual Sensor for Kinematic Estimation of Flexible Links in Parallel Robots.

    Science.gov (United States)

    Bengoa, Pablo; Zubizarreta, Asier; Cabanes, Itziar; Mancisidor, Aitziber; Pinto, Charles; Mata, Sara

    2017-08-23

    The control of flexible link parallel manipulators is still an open area of research, endpoint trajectory tracking being one of the main challenges in this type of robot. The flexibility and deformations of the limbs make the estimation of the Tool Centre Point (TCP) position a challenging one. Authors have proposed different approaches to estimate this deformation and deduce the location of the TCP. However, most of these approaches require expensive measurement systems or the use of high computational cost integration methods. This work presents a novel approach based on a virtual sensor which can not only precisely estimate the deformation of the flexible links in control applications (less than 2% error), but also its derivatives (less than 6% error in velocity and 13% error in acceleration) according to simulation results. The validity of the proposed Virtual Sensor is tested in a Delta Robot, where the position of the TCP is estimated based on the Virtual Sensor measurements with less than a 0.03% of error in comparison with the flexible approach developed in ADAMS Multibody Software.

  9. Virtual Sensor for Kinematic Estimation of Flexible Links in Parallel Robots

    Directory of Open Access Journals (Sweden)

    Pablo Bengoa

    2017-08-01

    Full Text Available The control of flexible link parallel manipulators is still an open area of research, endpoint trajectory tracking being one of the main challenges in this type of robot. The flexibility and deformations of the limbs make the estimation of the Tool Centre Point (TCP position a challenging one. Authors have proposed different approaches to estimate this deformation and deduce the location of the TCP. However, most of these approaches require expensive measurement systems or the use of high computational cost integration methods. This work presents a novel approach based on a virtual sensor which can not only precisely estimate the deformation of the flexible links in control applications (less than 2% error, but also its derivatives (less than 6% error in velocity and 13% error in acceleration according to simulation results. The validity of the proposed Virtual Sensor is tested in a Delta Robot, where the position of the TCP is estimated based on the Virtual Sensor measurements with less than a 0.03% of error in comparison with the flexible approach developed in ADAMS Multibody Software.

  10. Virtual Wireless Sensor Networks: Adaptive Brain-Inspired Configuration for Internet of Things Applications

    Directory of Open Access Journals (Sweden)

    Shinya Toyonaga

    2016-08-01

    Full Text Available Many researchers are devoting attention to the so-called “Internet of Things” (IoT, and wireless sensor networks (WSNs are regarded as a critical technology for realizing the communication infrastructure of the future, including the IoT. Against this background, virtualization is a crucial technique for the integration of multiple WSNs. Designing virtualized WSNs for actual environments will require further detailed studies. Within the IoT environment, physical networks can undergo dynamic change, and so, many problems exist that could prevent applications from running without interruption when using the existing approaches. In this paper, we show an overall architecture that is suitable for constructing and running virtual wireless sensor network (VWSN services within a VWSN topology. Our approach provides users with a reliable VWSN network by assigning redundant resources according to each user’s demand and providing a recovery method to incorporate environmental changes. We tested this approach by simulation experiment, with the results showing that the VWSN network is reliable in many cases, although physical deployment of sensor nodes and the modular structure of the VWSN will be quite important to the stability of services within the VWSN topology.

  11. Virtual Wireless Sensor Networks: Adaptive Brain-Inspired Configuration for Internet of Things Applications.

    Science.gov (United States)

    Toyonaga, Shinya; Kominami, Daichi; Murata, Masayuki

    2016-08-19

    Many researchers are devoting attention to the so-called "Internet of Things" (IoT), and wireless sensor networks (WSNs) are regarded as a critical technology for realizing the communication infrastructure of the future, including the IoT. Against this background, virtualization is a crucial technique for the integration of multiple WSNs. Designing virtualized WSNs for actual environments will require further detailed studies. Within the IoT environment, physical networks can undergo dynamic change, and so, many problems exist that could prevent applications from running without interruption when using the existing approaches. In this paper, we show an overall architecture that is suitable for constructing and running virtual wireless sensor network (VWSN) services within a VWSN topology. Our approach provides users with a reliable VWSN network by assigning redundant resources according to each user's demand and providing a recovery method to incorporate environmental changes. We tested this approach by simulation experiment, with the results showing that the VWSN network is reliable in many cases, although physical deployment of sensor nodes and the modular structure of the VWSN will be quite important to the stability of services within the VWSN topology.

  12. Virtual Distances Methodology as Verification Technique for AACMMs with a Capacitive Sensor Based Indexed Metrology Platform

    Directory of Open Access Journals (Sweden)

    Raquel Acero

    2016-11-01

    Full Text Available This paper presents a new verification procedure for articulated arm coordinate measuring machines (AACMMs together with a capacitive sensor-based indexed metrology platform (IMP based on the generation of virtual reference distances. The novelty of this procedure lays on the possibility of creating virtual points, virtual gauges and virtual distances through the indexed metrology platform’s mathematical model taking as a reference the measurements of a ball bar gauge located in a fixed position of the instrument’s working volume. The measurements are carried out with the AACMM assembled on the IMP from the six rotating positions of the platform. In this way, an unlimited number and types of reference distances could be created without the need of using a physical gauge, therefore optimizing the testing time, the number of gauge positions and the space needed in the calibration and verification procedures. Four evaluation methods are presented to assess the volumetric performance of the AACMM. The results obtained proved the suitability of the virtual distances methodology as an alternative procedure for verification of AACMMs using the indexed metrology platform.

  13. Virtual Distances Methodology as Verification Technique for AACMMs with a Capacitive Sensor Based Indexed Metrology Platform.

    Science.gov (United States)

    Acero, Raquel; Santolaria, Jorge; Brau, Agustin; Pueo, Marcos

    2016-11-18

    This paper presents a new verification procedure for articulated arm coordinate measuring machines (AACMMs) together with a capacitive sensor-based indexed metrology platform (IMP) based on the generation of virtual reference distances. The novelty of this procedure lays on the possibility of creating virtual points, virtual gauges and virtual distances through the indexed metrology platform's mathematical model taking as a reference the measurements of a ball bar gauge located in a fixed position of the instrument's working volume. The measurements are carried out with the AACMM assembled on the IMP from the six rotating positions of the platform. In this way, an unlimited number and types of reference distances could be created without the need of using a physical gauge, therefore optimizing the testing time, the number of gauge positions and the space needed in the calibration and verification procedures. Four evaluation methods are presented to assess the volumetric performance of the AACMM. The results obtained proved the suitability of the virtual distances methodology as an alternative procedure for verification of AACMMs using the indexed metrology platform.

  14. Virtual Environments for Visualizing Structural Health Monitoring Sensor Networks, Data, and Metadata.

    Science.gov (United States)

    Napolitano, Rebecca; Blyth, Anna; Glisic, Branko

    2018-01-16

    Visualization of sensor networks, data, and metadata is becoming one of the most pivotal aspects of the structural health monitoring (SHM) process. Without the ability to communicate efficiently and effectively between disparate groups working on a project, an SHM system can be underused, misunderstood, or even abandoned. For this reason, this work seeks to evaluate visualization techniques in the field, identify flaws in current practices, and devise a new method for visualizing and accessing SHM data and metadata in 3D. More precisely, the work presented here reflects a method and digital workflow for integrating SHM sensor networks, data, and metadata into a virtual reality environment by combining spherical imaging and informational modeling. Both intuitive and interactive, this method fosters communication on a project enabling diverse practitioners of SHM to efficiently consult and use the sensor networks, data, and metadata. The method is presented through its implementation on a case study, Streicker Bridge at Princeton University campus. To illustrate the efficiency of the new method, the time and data file size were compared to other potential methods used for visualizing and accessing SHM sensor networks, data, and metadata in 3D. Additionally, feedback from civil engineering students familiar with SHM is used for validation. Recommendations on how different groups working together on an SHM project can create SHM virtual environment and convey data to proper audiences, are also included.

  15. WAVEFRONT TESTER: Un nuevo laboratorio virtual para el estudio de los sensores frente de onda.

    Directory of Open Access Journals (Sweden)

    Vicente Ferrando Martín

    2016-01-01

    Full Text Available Se presenta un laboratorio virtual desarrollado en MATLAB GUI (Graphical User Interface para ser utilizado en la asignatura de "Tecnología de Sensores Optoelectrónicos" que se imparte en  "Escuela Técnica Superior de Ingeniería del Diseño" de la Universitat Politècnica de València. El objetivo de este laboratorio es servir de herramienta informática para el estudio de un sensor Shack Hartman y los parámetros que determinan el rango dinámico del mismo en la medida de las aberraciones. Se presentan distintos ejemplos realizados con diferentes aberraciones (desenfoque, astigmatismo, coma y para diferentes configuraciones del sensor.

  16. Virtual Sensors for On-line Wheel Wear and Part Roughness Measurement in the Grinding Process

    Science.gov (United States)

    Arriandiaga, Ander; Portillo, Eva; Sánchez, Jose A.; Cabanes, Itziar; Pombo, Iñigo

    2014-01-01

    Grinding is an advanced machining process for the manufacturing of valuable complex and accurate parts for high added value sectors such as aerospace, wind generation, etc. Due to the extremely severe conditions inside grinding machines, critical process variables such as part surface finish or grinding wheel wear cannot be easily and cheaply measured on-line. In this paper a virtual sensor for on-line monitoring of those variables is presented. The sensor is based on the modelling ability of Artificial Neural Networks (ANNs) for stochastic and non-linear processes such as grinding; the selected architecture is the Layer-Recurrent neural network. The sensor makes use of the relation between the variables to be measured and power consumption in the wheel spindle, which can be easily measured. A sensor calibration methodology is presented, and the levels of error that can be expected are discussed. Validation of the new sensor is carried out by comparing the sensor's results with actual measurements carried out in an industrial grinding machine. Results show excellent estimation performance for both wheel wear and surface roughness. In the case of wheel wear, the absolute error is within the range of microns (average value 32 μm). In the case of surface finish, the absolute error is well below Ra 1 μm (average value 0.32 μm). The present approach can be easily generalized to other grinding operations. PMID:24854055

  17. Virtual sensors for on-line wheel wear and part roughness measurement in the grinding process.

    Science.gov (United States)

    Arriandiaga, Ander; Portillo, Eva; Sánchez, Jose A; Cabanes, Itziar; Pombo, Iñigo

    2014-05-19

    Grinding is an advanced machining process for the manufacturing of valuable complex and accurate parts for high added value sectors such as aerospace, wind generation, etc. Due to the extremely severe conditions inside grinding machines, critical process variables such as part surface finish or grinding wheel wear cannot be easily and cheaply measured on-line. In this paper a virtual sensor for on-line monitoring of those variables is presented. The sensor is based on the modelling ability of Artificial Neural Networks (ANNs) for stochastic and non-linear processes such as grinding; the selected architecture is the Layer-Recurrent neural network. The sensor makes use of the relation between the variables to be measured and power consumption in the wheel spindle, which can be easily measured. A sensor calibration methodology is presented, and the levels of error that can be expected are discussed. Validation of the new sensor is carried out by comparing the sensor's results with actual measurements carried out in an industrial grinding machine. Results show excellent estimation performance for both wheel wear and surface roughness. In the case of wheel wear, the absolute error is within the range of microns (average value 32 μm). In the case of surface finish, the absolute error is well below Ra 1 μm (average value 0.32 μm). The present approach can be easily generalized to other grinding operations.

  18. Virtualization of Event Sources in Wireless Sensor Networks for the Internet of Things

    Directory of Open Access Journals (Sweden)

    Néstor Lucas Martínez

    2014-12-01

    Full Text Available Wireless Sensor Networks (WSNs are generally used to collect information from the environment. The gathered data are delivered mainly to sinks or gateways that become the endpoints where applications can retrieve and process such data. However, applications would also expect from a WSN an event-driven operational model, so that they can be notified whenever occur some specific environmental changes instead of continuously analyzing the data provided periodically. In either operational model, WSNs represent a collection of interconnected objects, as outlined by the Internet of Things. Additionally, in order to fulfill the Internet of Things principles, Wireless Sensor Networks must have a virtual representation that allows indirect access to their resources, a model that should also include the virtualization of event sources in a WSN. Thus, in this paper a model for a virtual representation of event sources in a WSN is proposed. They are modeled as internet resources that are accessible by any internet application, following an Internet of Things approach. The model has been tested in a real implementation where a WSN has been deployed in an open neighborhood environment. Different event sources have been identified in the proposed scenario, and they have been represented following the proposed model.

  19. Virtualization of event sources in wireless sensor networks for the internet of things.

    Science.gov (United States)

    Lucas Martínez, Néstor; Martínez, José-Fernán; Hernández Díaz, Vicente

    2014-12-01

    Wireless Sensor Networks (WSNs) are generally used to collect information from the environment. The gathered data are delivered mainly to sinks or gateways that become the endpoints where applications can retrieve and process such data. However, applications would also expect from a WSN an event-driven operational model, so that they can be notified whenever occur some specific environmental changes instead of continuously analyzing the data provided periodically. In either operational model, WSNs represent a collection of interconnected objects, as outlined by the Internet of Things. Additionally, in order to fulfill the Internet of Things principles, Wireless Sensor Networks must have a virtual representation that allows indirect access to their resources, a model that should also include the virtualization of event sources in a WSN. Thus, in this paper a model for a virtual representation of event sources in a WSN is proposed. They are modeled as internet resources that are accessible by any internet application, following an Internet of Things approach. The model has been tested in a real implementation where a WSN has been deployed in an open neighborhood environment. Different event sources have been identified in the proposed scenario, and they have been represented following the proposed model.

  20. Empirical evaluation of mapping functions for navigation in virtual reality using phones with integrated sensors

    KAUST Repository

    Benzina, Amal

    2012-01-01

    Mobile phones provide an interesting all-in-one alternative for 3D input devices in virtual environments. Mobile phones are becoming touch sensitive and spatially aware, and they are now part of our daily activities. We present Phone-Based Motion Control, a novel one-handed travel technique for a virtual environment. The technique benefits from the touch capability offered by growing number of mobile phones to change viewpoint translation in virtual environments, while the orientation of the viewpoint is controlled by built-in sensors in the mobile phone. The travel interaction separates translation (touch based translation control) and rotation (steer based rotation control), putting each set of degrees of freedom (DOF) to a separate interaction technique (separability). This paper examines, how many DOF are needed to perform the travel task as easy and comfortable as possible. It also investigates different mapping functions between the user\\'s actions on the mobile phone and the viewpoint change in the virtual environment. Therefore, four techniques are implemented: rotate by heading, rotate by roll, rotate by roll with fixed horizon and a merged rotation. Each technique has either 4 or 5 DOF and different mappings between phone and viewpoint coordinates in the virtual environment. We perform an extensive user study to explore different aspects related to the travel techniques in terms of DOF and mapping functions. Results of the user evaluation show that 4 DOF techniques seem to perform better the travel task. Even though, the results were not statistically decisive in favor of the usage of the mobile roll to control the viewpoint heading in the virtual environment despite the good results, there is a clear tendency from the users to prefer the mobile roll as the desired mapping. Copyright 2012 ACM.

  1. Virtual Mission Operations of Remote Sensors With Rapid Access To and From Space

    Science.gov (United States)

    Ivancic, William D.; Stewart, Dave; Walke, Jon; Dikeman, Larry; Sage, Steven; Miller, Eric; Northam, James; Jackson, Chris; Taylor, John; Lynch, Scott; hide

    2010-01-01

    This paper describes network-centric operations, where a virtual mission operations center autonomously receives sensor triggers, and schedules space and ground assets using Internet-based technologies and service-oriented architectures. For proof-of-concept purposes, sensor triggers are received from the United States Geological Survey (USGS) to determine targets for space-based sensors. The Surrey Satellite Technology Limited (SSTL) Disaster Monitoring Constellation satellite, the United Kingdom Disaster Monitoring Constellation (UK-DMC), is used as the space-based sensor. The UK-DMC s availability is determined via machine-to-machine communications using SSTL s mission planning system. Access to/from the UK-DMC for tasking and sensor data is via SSTL s and Universal Space Network s (USN) ground assets. The availability and scheduling of USN s assets can also be performed autonomously via machine-to-machine communications. All communication, both on the ground and between ground and space, uses open Internet standards.

  2. Sensor data fusion for textured reconstruction and virtual representation of alpine scenes

    Science.gov (United States)

    Häufel, Gisela; Bulatov, Dimitri; Solbrig, Peter

    2017-10-01

    The concept of remote sensing is to provide information about a wide-range area without making physical contact with this area. If, additionally to satellite imagery, images and videos taken by drones provide a more up-to-date data at a higher resolution, or accurate vector data is downloadable from the Internet, one speaks of sensor data fusion. The concept of sensor data fusion is relevant for many applications, such as virtual tourism, automatic navigation, hazard assessment, etc. In this work, we describe sensor data fusion aiming to create a semantic 3D model of an extremely interesting yet challenging dataset: An alpine region in Southern Germany. A particular challenge of this work is that rock faces including overhangs are present in the input airborne laser point cloud. The proposed procedure for identification and reconstruction of overhangs from point clouds comprises four steps: Point cloud preparation, filtering out vegetation, mesh generation and texturing. Further object types are extracted in several interesting subsections of the dataset: Building models with textures from UAV (Unmanned Aerial Vehicle) videos, hills reconstructed as generic surfaces and textured by the orthophoto, individual trees detected by the watershed algorithm, as well as the vector data for roads retrieved from openly available shapefiles and GPS-device tracks. We pursue geo-specific reconstruction by assigning texture and width to roads of several pre-determined types and modeling isolated trees and rocks using commercial software. For visualization and simulation of the area, we have chosen the simulation system Virtual Battlespace 3 (VBS3). It becomes clear that the proposed concept of sensor data fusion allows a coarse reconstruction of a large scene and, at the same time, an accurate and up-to-date representation of its relevant subsections, in which simulation can take place.

  3. Virtual-Lattice Based Intrusion Detection Algorithm over Actuator-Assisted Underwater Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Jing Yan

    2017-05-01

    Full Text Available Due to the lack of a physical line of defense, intrusion detection becomes one of the key issues in applications of underwater wireless sensor networks (UWSNs, especially when the confidentiality has prime importance. However, the resource-constrained property of UWSNs such as sparse deployment and energy constraint makes intrusion detection a challenging issue. This paper considers a virtual-lattice-based approach to the intrusion detection problem in UWSNs. Different from most existing works, the UWSNs consist of two kinds of nodes, i.e., sensor nodes (SNs, which cannot move autonomously, and actuator nodes (ANs, which can move autonomously according to the performance requirement. With the cooperation of SNs and ANs, the intruder detection probability is defined. Then, a virtual lattice-based monitor (VLM algorithm is proposed to detect the intruder. In order to reduce the redundancy of communication links and improve detection probability, an optimal and coordinative lattice-based monitor patrolling (OCLMP algorithm is further provided for UWSNs, wherein an equal price search strategy is given for ANs to find the shortest patrolling path. Under VLM and OCLMP algorithms, the detection probabilities are calculated, while the topology connectivity can be guaranteed. Finally, simulation results are presented to show that the proposed method in this paper can improve the detection accuracy and save the energy consumption compared with the conventional methods.

  4. Virtual-Lattice Based Intrusion Detection Algorithm over Actuator-Assisted Underwater Wireless Sensor Networks.

    Science.gov (United States)

    Yan, Jing; Li, Xiaolei; Luo, Xiaoyuan; Guan, Xinping

    2017-05-20

    Due to the lack of a physical line of defense, intrusion detection becomes one of the key issues in applications of underwater wireless sensor networks (UWSNs), especially when the confidentiality has prime importance. However, the resource-constrained property of UWSNs such as sparse deployment and energy constraint makes intrusion detection a challenging issue. This paper considers a virtual-lattice-based approach to the intrusion detection problem in UWSNs. Different from most existing works, the UWSNs consist of two kinds of nodes, i.e., sensor nodes (SNs), which cannot move autonomously, and actuator nodes (ANs), which can move autonomously according to the performance requirement. With the cooperation of SNs and ANs, the intruder detection probability is defined. Then, a virtual lattice-based monitor (VLM) algorithm is proposed to detect the intruder. In order to reduce the redundancy of communication links and improve detection probability, an optimal and coordinative lattice-based monitor patrolling (OCLMP) algorithm is further provided for UWSNs, wherein an equal price search strategy is given for ANs to find the shortest patrolling path. Under VLM and OCLMP algorithms, the detection probabilities are calculated, while the topology connectivity can be guaranteed. Finally, simulation results are presented to show that the proposed method in this paper can improve the detection accuracy and save the energy consumption compared with the conventional methods.

  5. Fault diagnosis of sensor networked structures with multiple faults using a virtual beam based approach

    Science.gov (United States)

    Wang, H.; Jing, X. J.

    2017-07-01

    This paper presents a virtual beam based approach suitable for conducting diagnosis of multiple faults in complex structures with limited prior knowledge of the faults involved. The ;virtual beam;, a recently-proposed concept for fault detection in complex structures, is applied, which consists of a chain of sensors representing a vibration energy transmission path embedded in the complex structure. Statistical tests and adaptive threshold are particularly adopted for fault detection due to limited prior knowledge of normal operational conditions and fault conditions. To isolate the multiple faults within a specific structure or substructure of a more complex one, a 'biased running' strategy is developed and embedded within the bacterial-based optimization method to construct effective virtual beams and thus to improve the accuracy of localization. The proposed method is easy and efficient to implement for multiple fault localization with limited prior knowledge of normal conditions and faults. With extensive experimental results, it is validated that the proposed method can localize both single fault and multiple faults more effectively than the classical trust index subtract on negative add on positive (TI-SNAP) method.

  6. A Virtual Geophysical Network: Using Industry Standard Technology to Link Geographically Distributed Sensors and Data Centers

    Science.gov (United States)

    Ahern, T. K.; Benson, R. B.; Crotwell, H. P.

    2003-12-01

    The IRIS Data Management System has long supported distributed data centers as a method of providing scientific researchers access to data from seismological networks around the world. For nearly a decade, the NetDC system used email as the method through which users could access data centers located around the globe in a seamless fashion. More recently the IRIS DMC has partnered with the University of South Carolina to develop a new method through which a virtual data center can be created. The Common Object Request Broker Architecture (CORBA) technology is an industry standard distributed computing architecture. Traditionally used by major corporations, IRIS has developed a Data Handling Interface (DHI) system that is capable of connecting services at participating data centers (servers) to applications running on end-users computing platforms (clients). For seismology we have identified three services. 1) A network service that provides information about geophysical observatories around the world such as where the sensors exist, what types of information are recorded on the sensors, and calibration information that allows proper use of the data, 2) an event service that allows applications to access information about earthquakes and seismological events and 3) waveform services that allow users to gain access to seismograms or time series data from other geophysical sensors. Seismological Data Centers operate the servers thereby allowing a variety of client applications to directly access the information at these data centers. Currently IRIS, the U. of South Carolina, UC Berkeley, and a European Data Center (ORFEUS) have been involved in the DHI project. This talk will highlight some of the DHI enabled clients that allow geophysical information to be directly transferred to the clients. Since the data center servers appear with the same interface specification (Interface Definition Language) a client that can talk to one DHI server can talk to any DHI enabled

  7. Nonlinear vibro-acoustic technique for land mine detection

    Science.gov (United States)

    Donskoy, Dmitri M.

    1998-09-01

    The innovative technique for detection of artificial objects, such as mines, pipes, containers, etc., buried in the ground, is developed and tested. The technique does not depend upon the material from which the object is fabricated whether it be metal, plastic, wood, or any other material. It depends upon the fact that a mine is a 'shell' whose purpose is to contain explosive materials and associated detonation apparatus. The mine shell is in contact with the soil in which it is buried. The shell is an acoustically compliant article, which compliance is notably different from the compliance of the surrounding soil. This difference is responsible for the mechanically nonlinear behavior of the soil/shell interface making it the detectable entity. Thus for this new technology, the fact that the mine is buried is turned to a detection advantage. Because the technique intrinsically detects buried 'shells,' it is insensitive to rocks, tree roots, chunks of metal, bricks, etc. which was confirmed experimentally. The paper discusses physical mechanisms of the nonlinear behavior of the soil-mine interface, the results of experimental investigation of the observed nonlinear interaction, and demonstration of landmine detection technique based on the discovered phenomenon.

  8. Periodicity-induced effects and methods in vibro-acoustics

    DEFF Research Database (Denmark)

    Sorokin, Sergey V.

    2015-01-01

    The paper is concerned with the modelling of wave propagation in and vibration of periodic elastic structures. Although analysis of waveguide properties of infinite periodic structures is a well establish research subject, some issues have not yet been fully addressed in the literature. The aim o...

  9. Mechanical and vibro-acoustic aspects of composite sandwich cylinders

    NARCIS (Netherlands)

    Yuan, C.

    2013-01-01

    Designing a fuselage involves many considerations such as strength and stability, fatigue, damage tolerance, fire and lightning resistance, thermal and acoustic insulation, production, inspection, maintenance and repair. In the background of the application of composite sandwich structures on the

  10. Vibro-Acoustics Modal Testing at NASA Langley Research Center

    Science.gov (United States)

    Pappa, Richard S.; Pritchard, Jocelyn I.; Buehrle, Ralph D.

    1999-01-01

    This paper summarizes on-going modal testing activities at the NASA Langley Research Center for two aircraft fuselage structures: a generic "aluminum testbed cylinder" (ATC) and a Beechcraft Starship fuselage (BSF). Subsequent acoustic tests will measure the interior noise field created by exterior mechanical and acoustic sources. These test results will provide validation databases for interior noise prediction codes on realistic aircraft fuselage structures. The ATC is a 12-ft-long, all-aluminum, scale model assembly. The BSF is a 40-ft-long, all-composite, complete aircraft fuselage. To date, two of seven test configurations of the ATC and all three test configurations of the BSF have been completed. The paper briefly describes the various test configurations, testing procedure, and typical results for frequencies up to 250 Hz.

  11. Periodicity-induced effects and method in vibro-acoustics

    DEFF Research Database (Denmark)

    Sorokin, Sergey V.

    2014-01-01

    of the lecture is concerned with the numerical implementation of the Floquet theory and the experimental demonstration of periodicity effects. A brief exposition of the Wave Finite Element method and an assessment of its validity range in canonical benchmark problems are presented. The results of experimental......The lecture is concerned with the modelling of wave propagation in and vibration of periodic elastic structures. Although analysis of wave-guide properties of infinite periodic structures is a well establish research subject, some issues have not yet been fully addressed in the literature. The aim...... of the lecture is to illustrate these issues in simple examples and to discuss possible applications and generalisations. First, the eigenfrequency spectra of finite periodic structures are compared with the location of stop-bands for their infinite counterparts. This is done with the special attention being...

  12. An Intelligent Active Video Surveillance System Based on the Integration of Virtual Neural Sensors and BDI Agents

    Science.gov (United States)

    Gregorio, Massimo De

    In this paper we present an intelligent active video surveillance system currently adopted in two different application domains: railway tunnels and outdoor storage areas. The system takes advantages of the integration of Artificial Neural Networks (ANN) and symbolic Artificial Intelligence (AI). This hybrid system is formed by virtual neural sensors (implemented as WiSARD-like systems) and BDI agents. The coupling of virtual neural sensors with symbolic reasoning for interpreting their outputs, makes this approach both very light from a computational and hardware point of view, and rather robust in performances. The system works on different scenarios and in difficult light conditions.

  13. A cost-effective sensor system to train light weight juggling using an interactive virtual reality interface

    Directory of Open Access Journals (Sweden)

    Bergamasco Massimo

    2011-12-01

    Full Text Available This paper presents a novel approach to train how to juggle using a sensor system based on one of the most commercial, sophisticated and accessible input devices, the Wii Remote controller. This platform, particularly its infrared camera, is used to develop a real-time sensor system for hand motion tracking and fit it into a virtual reality interface. The quality of our algorithm was tested through this 3D virtual interface, which has the finality to give the user visual feedback of his/her hand positions, and created for the user the sensation of juggling.

  14. Interacción Natural Basada en un Conjunto Mínimo de Sensores Inerciales para Realidad Virtual sin Cables

    OpenAIRE

    De-la-Rubia-Cuestas, Ernesto Jesús

    2014-01-01

    La Realidad Virtual tiene un enorme potencial aún por explotar. Esta tesis doctoral pretende ir un paso más allá en el desarrollo de sistemas de Realidad Virtual inmersivos. En concreto, su objetivo fundamental es diseñar, desarrollar y evaluar una plataforma experimental sin cables para investigación en Realidad Virtual inmersiva con navegación natural e interacción manual basada en un conjunto mínimo de sensores inerciales. Para ello se emplea metodología científica desde la perspectiva de ...

  15. Sensor-Augmented Virtual Labs: Using Physical Interactions with Science Simulations to Promote Understanding of Gas Behavior

    Science.gov (United States)

    Chao, Jie; Chiu, Jennifer L.; DeJaegher, Crystal J.; Pan, Edward A.

    2016-02-01

    Deep learning of science involves integration of existing knowledge and normative science concepts. Past research demonstrates that combining physical and virtual labs sequentially or side by side can take advantage of the unique affordances each provides for helping students learn science concepts. However, providing simultaneously connected physical and virtual experiences has the potential to promote connections among ideas. This paper explores the effect of augmenting a virtual lab with physical controls on high school chemistry students' understanding of gas laws. We compared students using the augmented virtual lab to students using a similar sensor-based physical lab with teacher-led discussions. Results demonstrate that students in the augmented virtual lab condition made significant gains from pretest and posttest and outperformed traditional students on some but not all concepts. Results provide insight into incorporating mixed-reality technologies into authentic classroom settings.

  16. Motor Ingredients Derived from a Wearable Sensor-Based Virtual Reality System for Frozen Shoulder Rehabilitation

    Directory of Open Access Journals (Sweden)

    Si-Huei Lee

    2016-01-01

    Full Text Available Objective. This study aims to extract motor ingredients through data mining from wearable sensors in a virtual reality goal-directed shoulder rehabilitation (GDSR system and to examine their effects toward clinical assessment. Design. A single-group before/after comparison. Setting. Outpatient research hospital. Subjects. 16 patients with frozen shoulder. Interventions. The rehabilitation treatment involved GDSR exercises, hot pack, and interferential therapy. All patients first received hot pack and interferential therapy on the shoulder joints before engaging in the exercises. The GDSR exercise sessions were 40 minutes twice a week for 4 weeks. Main Measures. Clinical assessments included Constant and Murley score, range of motion of the shoulder, and muscle strength of upper arm as main measures. Motor indices from sensor data and task performance were measured as secondary measures. Results. The pre- and posttest results for task performance, motor indices, and the clinical assessments indicated significant improvement for the majority of the assessed items. Correlation analysis between the task performance and clinical assessments revealed significant correlations among a number of items. Stepwise regression analysis showed that task performance effectively predicted the results of several clinical assessment items. Conclusions. The motor ingredients derived from the wearable sensor and task performance are applicable and adequate to examine and predict clinical improvement after GDSR training.

  17. Oversampling in virtual visual sensors as a means to recover higher modes of vibration

    Science.gov (United States)

    Shariati, Ali; Schumacher, Thomas

    2015-03-01

    Vibration-based structural health monitoring (SHM) techniques require modal information from the monitored structure in order to estimate the location and severity of damage. Natural frequencies also provide useful information to calibrate finite element models. There are several types of physical sensors that can measure the response over a range of frequencies. For most of those sensors however, accessibility, limitation of measurement points, wiring, and high system cost represent major challenges. Recent optical sensing approaches offer advantages such as easy access to visible areas, distributed sensing capabilities, and comparatively inexpensive data recording while having no wiring issues. In this research we propose a novel methodology to measure natural frequencies of structures using digital video cameras based on virtual visual sensors (VVS). In our initial study where we worked with commercially available inexpensive digital video cameras we found that for multiple degrees of freedom systems it is difficult to detect all of the natural frequencies simultaneously due to low quantization resolution. In this study we show how oversampling enabled by the use of high-end high-frame-rate video cameras enable recovering all of the three natural frequencies from a three story lab-scale structure.

  18. Smart sensors and virtual physiology human approach as a basis of personalized therapies in diabetes mellitus.

    Science.gov (United States)

    Fernández Peruchena, Carlos M; Prado-Velasco, Manuel

    2010-01-01

    Diabetes mellitus (DM) has a growing incidence and prevalence in modern societies, pushed by the aging and change of life styles. Despite the huge resources dedicated to improve their quality of life, mortality and morbidity rates, these are still very poor. In this work, DM pathology is revised from clinical and metabolic points of view, as well as mathematical models related to DM, with the aim of justifying an evolution of DM therapies towards the correction of the physiological metabolic loops involved. We analyze the reliability of mathematical models, under the perspective of virtual physiological human (VPH) initiatives, for generating and integrating customized knowledge about patients, which is needed for that evolution. Wearable smart sensors play a key role in this frame, as they provide patient's information to the models.A telehealthcare computational architecture based on distributed smart sensors (first processing layer) and personalized physiological mathematical models integrated in Human Physiological Images (HPI) computational components (second processing layer), is presented. This technology was designed for a renal disease telehealthcare in earlier works and promotes crossroads between smart sensors and the VPH initiative. We suggest that it is able to support a truly personalized, preventive, and predictive healthcare model for the delivery of evolved DM therapies.

  19. ROI-ORIENTATED SENSOR CORRECTION BASED ON VIRTUAL STEADY REIMAGING MODEL FOR WIDE SWATH HIGH RESOLUTION OPTICAL SATELLITE IMAGERY

    Directory of Open Access Journals (Sweden)

    Y. Zhu

    2017-09-01

    Full Text Available To meet the requirement of high accuracy and high speed processing for wide swath high resolution optical satellite imagery under emergency situation in both ground processing system and on-board processing system. This paper proposed a ROI-orientated sensor correction algorithm based on virtual steady reimaging model for wide swath high resolution optical satellite imagery. Firstly, the imaging time and spatial window of the ROI is determined by a dynamic search method. Then, the dynamic ROI sensor correction model based on virtual steady reimaging model is constructed. Finally, the corrected image corresponding to the ROI is generated based on the coordinates mapping relationship which is established by the dynamic sensor correction model for corrected image and rigours imaging model for original image. Two experimental results show that the image registration between panchromatic and multispectral images can be well achieved and the image distortion caused by satellite jitter can be also corrected efficiently.

  20. Hybrid Motion Planning Method for Autonomous Robots Using Kinect Based Sensor Fusion and Virtual Plane Approach in Dynamic Environments

    Directory of Open Access Journals (Sweden)

    Doopalam Tuvshinjargal

    2015-01-01

    Full Text Available A new reactive motion planning method for an autonomous vehicle in dynamic environments is proposed. The new dynamic motion planning method combines a virtual plane based reactive motion planning technique with a sensor fusion based obstacle detection approach, which results in improving robustness and autonomy of vehicle navigation within unpredictable dynamic environments. The key feature of the new reactive motion planning method is based on a local observer in the virtual plane which allows the effective transformation of complex dynamic planning problems into simple stationary in the virtual plane. In addition, a sensor fusion based obstacle detection technique provides the pose estimation of moving obstacles by using a Kinect sensor and a sonar sensor, which helps to improve the accuracy and robustness of the reactive motion planning approach in uncertain dynamic environments. The performance of the proposed method was demonstrated through not only simulation studies but also field experiments using multiple moving obstacles even in hostile environments where conventional method failed.

  1. A Model-Based Virtual Sensor for Condition Monitoring of Li-Ion Batteries in Cyber-Physical Vehicle Systems

    Directory of Open Access Journals (Sweden)

    Luciano Sánchez

    2017-01-01

    Full Text Available A model-based virtual sensor for assessing the health of rechargeable batteries for cyber-physical vehicle systems (CPVSs is presented that can exploit coarse data streamed from on-vehicle sensors of current, voltage, and temperature. First-principle-based models are combined with knowledge acquired from data in a semiphysical arrangement. The dynamic behaviour of the battery is embodied in the parametric definition of a set of differential equations, and fuzzy knowledge bases are embedded as nonlinear blocks in these equations, providing a human understandable reading of the State of Health of the CPVS that can be easily integrated in the fleet through-life management.

  2. Sensor virtual neuronal con variables instrumentales y su aplicación en un Convertidor Teniente

    Directory of Open Access Journals (Sweden)

    Suárez S. Alejandro

    2011-01-01

    Full Text Available Resumen: Se propone el diseño de un sensor virtual para medir la temperatura del baño de metal blanco en un Convertidor Teniente, utilizando redes neuronales a través de un nuevo método de entrenamiento que utiliza el concepto de variables instrumentales. Este nuevo tipo de entrenamiento será comparado con el método de gradiente descendente, el cual al estar basado en ajuste por mínimos cuadrados presenta sesgo en sus parámetros, producto del ruido de medición. La apuesta es que el método de variables instrumentales resuelva este problema, entregando una red con parámetros ajustados sin sesgo, lo que se verá reflejado en que la salida de esta red, se ajustará de mejor forma a la señal real que el método tradicional de gradiente descendente. Los resultados demuestran que la propuesta planteada entrega un sensor con mejor ajuste que el algoritmo tradicional cuando el instrumento real no se encuentra disponible. La aplicación específica del sensor virtual de temperatura para el Convertidor Teniente presenta gran interés para la industria debido al alto costo de los instrumentos que actualmente pueden cumplir dicha función. Palabras clave: sensores virtuales, redes neuronales, variables instrumentales, procesos de producción de cobre, instrumentación y mediciones virtuales

  3. In-vehicle group activity modeling and simulation in sensor-based virtual environment

    Science.gov (United States)

    Shirkhodaie, Amir; Telagamsetti, Durga; Poshtyar, Azin; Chan, Alex; Hu, Shuowen

    2016-05-01

    Human group activity recognition is a very complex and challenging task, especially for Partially Observable Group Activities (POGA) that occur in confined spaces with limited visual observability and often under severe occultation. In this paper, we present IRIS Virtual Environment Simulation Model (VESM) for the modeling and simulation of dynamic POGA. More specifically, we address sensor-based modeling and simulation of a specific category of POGA, called In-Vehicle Group Activities (IVGA). In VESM, human-alike animated characters, called humanoids, are employed to simulate complex in-vehicle group activities within the confined space of a modeled vehicle. Each articulated humanoid is kinematically modeled with comparable physical attributes and appearances that are linkable to its human counterpart. Each humanoid exhibits harmonious full-body motion - simulating human-like gestures and postures, facial impressions, and hands motions for coordinated dexterity. VESM facilitates the creation of interactive scenarios consisting of multiple humanoids with different personalities and intentions, which are capable of performing complicated human activities within the confined space inside a typical vehicle. In this paper, we demonstrate the efficiency and effectiveness of VESM in terms of its capabilities to seamlessly generate time-synchronized, multi-source, and correlated imagery datasets of IVGA, which are useful for the training and testing of multi-source full-motion video processing and annotation. Furthermore, we demonstrate full-motion video processing of such simulated scenarios under different operational contextual constraints.

  4. Reliable Geographical Forwarding in Cognitive Radio Sensor Networks Using Virtual Clusters

    Directory of Open Access Journals (Sweden)

    Suleiman Zubair

    2014-05-01

    Full Text Available The need for implementing reliable data transfer in resource-constrained cognitive radio ad hoc networks is still an open issue in the research community. Although geographical forwarding schemes are characterized by their low overhead and efficiency in reliable data transfer in traditional wireless sensor network, this potential is still yet to be utilized for viable routing options in resource-constrained cognitive radio ad hoc networks in the presence of lossy links. In this paper, a novel geographical forwarding technique that does not restrict the choice of the next hop to the nodes in the selected route is presented. This is achieved by the creation of virtual clusters based on spectrum correlation from which the next hop choice is made based on link quality. The design maximizes the use of idle listening and receiver contention prioritization for energy efficiency, the avoidance of routing hot spots and stability. The validation result, which closely follows the simulation result, shows that the developed scheme can make more advancement to the sink as against the usual decisions of relevant ad hoc on-demand distance vector route select operations, while ensuring channel quality. Further simulation results have shown the enhanced reliability, lower latency and energy efficiency of the presented scheme.

  5. Virtual Sensors: Using Data Mining Techniques to Efficiently Estimate Remote Sensing Spectra

    Science.gov (United States)

    Srivastava, Ashok N.; Oza, Nikunj; Stroeve, Julienne

    2004-01-01

    Various instruments are used to create images of the Earth and other objects in the universe in a diverse set of wavelength bands with the aim of understanding natural phenomena. These instruments are sometimes built in a phased approach, with some measurement capabilities being added in later phases. In other cases, there may not be a planned increase in measurement capability, but technology may mature to the point that it offers new measurement capabilities that were not available before. In still other cases, detailed spectral measurements may be too costly to perform on a large sample. Thus, lower resolution instruments with lower associated cost may be used to take the majority of measurements. Higher resolution instruments, with a higher associated cost may be used to take only a small fraction of the measurements in a given area. Many applied science questions that are relevant to the remote sensing community need to be addressed by analyzing enormous amounts of data that were generated from instruments with disparate measurement capability. This paper addresses this problem by demonstrating methods to produce high accuracy estimates of spectra with an associated measure of uncertainty from data that is perhaps nonlinearly correlated with the spectra. In particular, we demonstrate multi-layer perceptrons (MLPs), Support Vector Machines (SVMs) with Radial Basis Function (RBF) kernels, and SVMs with Mixture Density Mercer Kernels (MDMK). We call this type of an estimator a Virtual Sensor because it predicts, with a measure of uncertainty, unmeasured spectral phenomena.

  6. Reliable geographical forwarding in cognitive radio sensor networks using virtual clusters.

    Science.gov (United States)

    Zubair, Suleiman; Fisal, Norsheila

    2014-05-21

    The need for implementing reliable data transfer in resource-constrained cognitive radio ad hoc networks is still an open issue in the research community. Although geographical forwarding schemes are characterized by their low overhead and efficiency in reliable data transfer in traditional wireless sensor network, this potential is still yet to be utilized for viable routing options in resource-constrained cognitive radio ad hoc networks in the presence of lossy links. In this paper, a novel geographical forwarding technique that does not restrict the choice of the next hop to the nodes in the selected route is presented. This is achieved by the creation of virtual clusters based on spectrum correlation from which the next hop choice is made based on link quality. The design maximizes the use of idle listening and receiver contention prioritization for energy efficiency, the avoidance of routing hot spots and stability. The validation result, which closely follows the simulation result, shows that the developed scheme can make more advancement to the sink as against the usual decisions of relevant ad hoc on-demand distance vector route select operations, while ensuring channel quality. Further simulation results have shown the enhanced reliability, lower latency and energy efficiency of the presented scheme.

  7. Automated detection of epileptic ripples in MEG using beamformer-based virtual sensors

    Science.gov (United States)

    Migliorelli, Carolina; Alonso, Joan F.; Romero, Sergio; Nowak, Rafał; Russi, Antonio; Mañanas, Miguel A.

    2017-08-01

    Objective. In epilepsy, high-frequency oscillations (HFOs) are expressively linked to the seizure onset zone (SOZ). The detection of HFOs in the noninvasive signals from scalp electroencephalography (EEG) and magnetoencephalography (MEG) is still a challenging task. The aim of this study was to automate the detection of ripples in MEG signals by reducing the high-frequency noise using beamformer-based virtual sensors (VSs) and applying an automatic procedure for exploring the time-frequency content of the detected events. Approach. Two-hundred seconds of MEG signal and simultaneous iEEG were selected from nine patients with refractory epilepsy. A two-stage algorithm was implemented. Firstly, beamforming was applied to the whole head to delimitate the region of interest (ROI) within a coarse grid of MEG-VS. Secondly, a beamformer using a finer grid in the ROI was computed. The automatic detection of ripples was performed using the time-frequency response provided by the Stockwell transform. Performance was evaluated through comparisons with simultaneous iEEG signals. Main results. ROIs were located within the seizure-generating lobes in the nine subjects. Precision and sensitivity values were 79.18% and 68.88%, respectively, by considering iEEG-detected events as benchmarks. A higher number of ripples were detected inside the ROI compared to the same region in the contralateral lobe. Significance. The evaluation of interictal ripples using non-invasive techniques can help in the delimitation of the epileptogenic zone and guide placement of intracranial electrodes. This is the first study that automatically detects ripples in MEG in the time domain located within the clinically expected epileptic area taking into account the time-frequency characteristics of the events through the whole signal spectrum. The algorithm was tested against intracranial recordings, the current gold standard. Further studies should explore this approach to enable the localization of

  8. Virtual Redundancy for Safety Assurance in the Presence of Sensor Failures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Both autopilot systems and human pilots, particularly human pilots operating in instrument meteorological conditions, rely heavily on sensor feedback to safely...

  9. Monitoring of Structures and Mechanical Systems Using Virtual Visual Sensors for Video Analysis: Fundamental Concept and Proof of Feasibility

    Directory of Open Access Journals (Sweden)

    Thomas Schumacher

    2013-12-01

    Full Text Available Structural health monitoring (SHM has become a viable tool to provide owners of structures and mechanical systems with quantitative and objective data for maintenance and repair. Traditionally, discrete contact sensors such as strain gages or accelerometers have been used for SHM. However, distributed remote sensors could be advantageous since they don’t require cabling and can cover an area rather than a limited number of discrete points. Along this line we propose a novel monitoring methodology based on video analysis. By employing commercially available digital cameras combined with efficient signal processing methods we can measure and compute the fundamental frequency of vibration of structural systems. The basic concept is that small changes in the intensity value of a monitored pixel with fixed coordinates caused by the vibration of structures can be captured by employing techniques such as the Fast Fourier Transform (FFT. In this paper we introduce the basic concept and mathematical theory of this proposed so-called virtual visual sensor (VVS, we present a set of initial laboratory experiments to demonstrate the accuracy of this approach, and provide a practical in-service monitoring example of an in-service bridge. Finally, we discuss further work to improve the current methodology.

  10. submitter Estimation of stepping motor current from long distances through cable-length-adaptive piecewise affine virtual sensor

    CERN Document Server

    Oliveri, Alberto; Masi, Alessandro; Storace, Marco

    2015-01-01

    In this paper a piecewise affine virtual sensor is used for the estimation of the motor-side current of hybrid stepper motors, which actuate the LHC (Large Hadron Collider) collimators at CERN. The estimation is performed starting from measurements of the current in the driver, which is connected to the motor by a long cable (up to 720 m). The measured current is therefore affected by noise and ringing phenomena. The proposed method does not require a model of the cable, since it is only based on measured data and can be used with cables of different length. A circuit architecture suitable for FPGA implementation has been designed and the effects of fixed point representation of data are analyzed.

  11. Hyperspectral target detection analysis of a cluttered scene from a virtual airborne sensor platform using MuSES

    Science.gov (United States)

    Packard, Corey D.; Viola, Timothy S.; Klein, Mark D.

    2017-10-01

    The ability to predict spectral electro-optical (EO) signatures for various targets against realistic, cluttered backgrounds is paramount for rigorous signature evaluation. Knowledge of background and target signatures, including plumes, is essential for a variety of scientific and defense-related applications including contrast analysis, camouflage development, automatic target recognition (ATR) algorithm development and scene material classification. The capability to simulate any desired mission scenario with forecast or historical weather is a tremendous asset for defense agencies, serving as a complement to (or substitute for) target and background signature measurement campaigns. In this paper, a systematic process for the physical temperature and visible-through-infrared radiance prediction of several diverse targets in a cluttered natural environment scene is presented. The ability of a virtual airborne sensor platform to detect and differentiate targets from a cluttered background, from a variety of sensor perspectives and across numerous wavelengths in differing atmospheric conditions, is considered. The process described utilizes the thermal and radiance simulation software MuSES and provides a repeatable, accurate approach for analyzing wavelength-dependent background and target (including plume) signatures in multiple band-integrated wavebands (multispectral) or hyperspectrally. The engineering workflow required to combine 3D geometric descriptions, thermal material properties, natural weather boundary conditions, all modes of heat transfer and spectral surface properties is summarized. This procedure includes geometric scene creation, material and optical property attribution, and transient physical temperature prediction. Radiance renderings, based on ray-tracing and the Sandford-Robertson BRDF model, are coupled with MODTRAN for the inclusion of atmospheric effects. This virtual hyperspectral/multispectral radiance prediction methodology has been

  12. Virtual Object Access Rights to Enable Multi-Party Use of Sensors

    NARCIS (Netherlands)

    Tilanus, P.A.J.; Ran, B.G.; Faeth, M.S.; Kelaidonis, D.; Stavroulaki, V.

    2013-01-01

    Today there are more sensors and actuators in isolated intranets of things than in the overall internet of things (IoT). This paper discusses the motives to open up an intranet of things and make the things part of the global IoT, identifies the requirements from the involved parties, and extracts

  13. Integrating Flexible Sensor and Virtual Self-Organizing DC Grid Model With Cloud Computing for Blood Leakage Detection During Hemodialysis.

    Science.gov (United States)

    Huang, Ping-Tzan; Jong, Tai-Lang; Li, Chien-Ming; Chen, Wei-Ling; Lin, Chia-Hung

    2017-08-01

    Blood leakage and blood loss are serious complications during hemodialysis. From the hemodialysis survey reports, these life-threatening events occur to attract nephrology nurses and patients themselves. When the venous needle and blood line are disconnected, it takes only a few minutes for an adult patient to lose over 40% of his / her blood, which is a sufficient amount of blood loss to cause the patient to die. Therefore, we propose integrating a flexible sensor and self-organizing algorithm to design a cloud computing-based warning device for blood leakage detection. The flexible sensor is fabricated via a screen-printing technique using metallic materials on a soft substrate in an array configuration. The self-organizing algorithm constructs a virtual direct current grid-based alarm unit in an embedded system. This warning device is employed to identify blood leakage levels via a wireless network and cloud computing. It has been validated experimentally, and the experimental results suggest specifications for its commercial designs. The proposed model can also be implemented in an embedded system.

  14. Energy performance assessment of virtualization technologies using small environmental monitoring sensors.

    Science.gov (United States)

    Liu, Lu; Masfary, Osama; Antonopoulos, Nick

    2012-01-01

    The increasing trends of electrical consumption within data centres are a growing concern for business owners as they are quickly becoming a large fraction of the total cost of ownership. Ultra small sensors could be deployed within a data centre to monitor environmental factors to lower the electrical costs and improve the energy efficiency. Since servers and air conditioners represent the top users of electrical power in the data centre, this research sets out to explore methods from each subsystem of the data centre as part of an overall energy efficient solution. In this paper, we investigate the current trends of Green IT awareness and how the deployment of small environmental sensors and Site Infrastructure equipment optimization techniques which can offer a solution to a global issue by reducing carbon emissions.

  15. Energy Performance Assessment of Virtualization Technologies Using Small Environmental Monitoring Sensors

    Directory of Open Access Journals (Sweden)

    Lu Liu

    2012-05-01

    Full Text Available The increasing trends of electrical consumption within data centres are a growing concern for business owners as they are quickly becoming a large fraction of the total cost of ownership. Ultra small sensors could be deployed within a data centre to monitor environmental factors to lower the electrical costs and improve the energy efficiency. Since servers and air conditioners represent the top users of electrical power in the data centre, this research sets out to explore methods from each subsystem of the data centre as part of an overall energy efficient solution. In this paper, we investigate the current trends of Green IT awareness and how the deployment of small environmental sensors and Site Infrastructure equipment optimization techniques which can offer a solution to a global issue by reducing carbon emissions.

  16. Virtual Stream Stage Sensor Using Projected Geometry and Augmented Reality for Crowdsourcing Citizen Science Applications

    Science.gov (United States)

    Demir, I.; Villanueva, P.; Sermet, M. Y.

    2016-12-01

    Accurately measuring the surface level of a river is a vital component of environmental monitoring and modeling efforts. Reliable data points are required for calibrating the statistical models that are used for, among other things, flood prediction and model validation. While current embedded monitoring systems provide accurate measurements, the cost to replicate this current system on a large scale is prohibitively expensive, limiting the quantity of data available. In this project, we describe a new method to accurately measure river levels using smartphone sensors. We take three pictures of the same point on the river's surface and perform calculations based on the GPS location and spatial orientation of the smartphone for each picture using projected geometry. Augmented reality is used to improve the accuracy of smartphone sensor readings. This proposed implementation is significantly cheaper than existing water measuring systems while offering similar accuracy. Additionally, since the measurements are taken by sensors that are commonly found in smartphones, crowdsourcing the collection of river measurements to citizen-scientists is possible. Thus, our proposed method leads to a much higher quantity of reliable data points than currently possible at a fraction of the cost. Sample runs and an analysis of the results are included. The presentation concludes with a discussion of future work, including applications to other fields and plans to implement a fully automated system using this method in tandem with image recognition and machine learning.

  17. Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, H. [PBI-Dansensor A/S (Denmark); Toft Soerensen, O. [Risoe National Lab., Materials Research Dept. (Denmark)

    1999-10-01

    A new type of ceramic oxygen sensors based on semiconducting oxides was developed in this project. The advantage of these sensors compared to standard ZrO{sub 2} sensors is that they do not require a reference gas and that they can be produced in small sizes. The sensor design and the techniques developed for production of these sensors are judged suitable by the participating industry for a niche production of a new generation of oxygen sensors. Materials research on new oxygen ion conducting conductors both for applications in oxygen sensors and in fuel was also performed in this project and finally a new process was developed for fabrication of ceramic tubes by dip-coating. (EHS)

  18. Sensors

    CERN Document Server

    Pigorsch, Enrico

    1997-01-01

    This is the 5th edition of the Metra Martech Directory "EUROPEAN CENTRES OF EXPERTISE - SENSORS." The entries represent a survey of European sensors development. The new edition contains 425 detailed profiles of companies and research institutions in 22 countries. This is reflected in the diversity of sensors development programmes described, from sensors for physical parameters to biosensors and intelligent sensor systems. We do not claim that all European organisations developing sensors are included, but this is a good cross section from an invited list of participants. If you see gaps or omissions, or would like your organisation to be included, please send details. The data base invites the formation of effective joint ventures by identifying and providing access to specific areas in which organisations offer collaboration. This issue is recognised to be of great importance and most entrants include details of collaboration offered and sought. We hope the directory on Sensors will help you to find the ri...

  19. Virtual Vision

    Science.gov (United States)

    Terzopoulos, Demetri; Qureshi, Faisal Z.

    Computer vision and sensor networks researchers are increasingly motivated to investigate complex multi-camera sensing and control issues that arise in the automatic visual surveillance of extensive, highly populated public spaces such as airports and train stations. However, they often encounter serious impediments to deploying and experimenting with large-scale physical camera networks in such real-world environments. We propose an alternative approach called "Virtual Vision", which facilitates this type of research through the virtual reality simulation of populated urban spaces, camera sensor networks, and computer vision on commodity computers. We demonstrate the usefulness of our approach by developing two highly automated surveillance systems comprising passive and active pan/tilt/zoom cameras that are deployed in a virtual train station environment populated by autonomous, lifelike virtual pedestrians. The easily reconfigurable virtual cameras distributed in this environment generate synthetic video feeds that emulate those acquired by real surveillance cameras monitoring public spaces. The novel multi-camera control strategies that we describe enable the cameras to collaborate in persistently observing pedestrians of interest and in acquiring close-up videos of pedestrians in designated areas.

  20. A combined parabolic-integral equation approach to the acoustic simulation of vibro-acoustic imaging.

    Science.gov (United States)

    Malcolm, A E; Reitich, F; Yang, J; Greenleaf, J F; Fatemi, M

    2008-11-01

    This paper aims to model ultrasound vibro-acoustography to improve our understanding of the underlying physics of the technique thus facilitating the collection of better images. Ultrasound vibro-acoustography is a novel imaging technique combining the resolution of high-frequency imaging with the clean (speckle-free) images obtained with lower frequency techniques. The challenge in modeling such an experiment is in the variety of scales important to the final image. In contrast to other approaches for modeling such problems, we break the experiment into three parts: high-frequency propagation, non-linear interaction and the propagation of the low-frequency acoustic emission. We then apply different modeling strategies to each part. For the high-frequency propagation we choose a parabolic approximation as the field has a strong preferred direction and small propagation angles. The non-linear interaction is calculated directly with Fourier methods for computing derivatives. Because of the low-frequency omnidirectional nature of the acoustic emission field and the piecewise constant medium we model the low-frequency field with a surface integral approach. We use our model to compare with experimental data and to visualize the relevant fields at points in the experiment where laboratory data is difficult to collect, in particular the source of the low-frequency field. To simulate experimental conditions we perform the simulations with the two frequencies 3 and 3.05 MHz with an inclusion of varying velocity submerged in water.

  1. Sonic Boom Vibro-Acoustic Simulations using Multiple Point Sources Project

    Data.gov (United States)

    National Aeronautics and Space Administration — AVEC proposes an innovative concept for the evaluation of human response studies to sonic booms inside realistic structures. The approach proposed is to simulate the...

  2. Numerical prediction of combustion induced vibro-acoustical instabilities in a gas turbine combustor

    NARCIS (Netherlands)

    Pozarlik, Artur Krzysztof; Kok, Jacobus B.W.; M. Pawelczyk, D. Bismor

    2009-01-01

    Introduction of lean premixed combustion to gas turbine technology reduced the emission of harmful exhaust gas species, but due to the high sensitivity of lean flames to acoustic perturbations, the average life time of gas turbine engines was decreased significantly. Very dangerous to the integrity

  3. The Shock and Vibration Bulletin. Part 3. Aerospace Vehicles, Vibro-acoustics

    Science.gov (United States)

    1975-06-01

    Patterson Air Force Base, Ohio ADDRESS OF WELCOME •, Mr. George Peterson, Director, Air Force Materials Laboratory, Wright-Patterson Air Force Base, Ohio...H. W. Nunez, Sandia Laboratories, Albuquerque, New Mexico EVALUATION OF THE SHOCK PULSE TECHNIQUE TO THE UH-I SERIES HELICOPTER J. A George , T. C...MULTIDIRECTIONAL MOBILITY DATA FOR BEAMS D J. Ewins, Imperial College of Science and Technology,. London, England and P. T Gleeson , Moddlesex Polytechnic and

  4. Vibro-acoustic analysis of spacecraft structures with thin air layers

    OpenAIRE

    Chimeno Manguan, Marcos

    2015-01-01

    Esta Tesis presenta un estudio sobre el comportamiento vibroacústico de estructuras espaciales que incluyen capas de aire delgadas, así como sobre su modelización numérica. Las capas de aire pueden constituir un elemento fundamental en estos sistemas, como paneles solares plegados, que se consideran el caso de estudio en este trabajo. Para evaluar la influencia de las capas de aire en la respuesta dinámica del sistema se presenta el uso de modelos unidimensionales. La modelización de estos si...

  5. Pointers, Lessons Learned, and Rules of Thumb for Successful Vibro-Acoustic Data Acquisition

    Science.gov (United States)

    Rossoni, Peter

    1998-01-01

    This presentation contains helpful pointers for successful vibroacoustic data acquisition in the following three areas: Instrumentation, Vibration Control and Pyro-shock data acquisition and analysis. A helpful bibliography is provided.

  6. Thermo-Vibro-Acoustic Loads and Fatigue of Hypersonic Flight Vehicle Structure

    Science.gov (United States)

    2009-06-01

    measurements. Rohr has a selection of B&K. Kulite. and Endevco microphones for use in this program. B&K microphones will be suspended in the PWT just...outside the high-temperature area. Kulite or Endevco microphones will be flush mounted in the panel/fixture frame assembly for temperatures up to 500°F

  7. Vibro-acoustical instabilities induced by combustion dynamics in gas turbine combustors

    NARCIS (Netherlands)

    Pozarlik, Artur Krzysztof

    2010-01-01

    The lean premixed combustion suffers from a high sensitivity to thermo-acoustic instabilities which may occur in acombustion chamber of a gas turbine. The high level of acoustic excitation is hazardous to the combustion chamber walls(liner). The situation is even worse when mutual interaction

  8. Final assessment of vibro-acoustic source strength descriptors of helicopter gearboxes

    DEFF Research Database (Denmark)

    Ohlrich, Mogens; Rasmussen, Ulrik Møller

    1996-01-01

    Two novel measurement techniques have been developed for quantifying the vibro-aqcoustic source strength of lightweight helicopter gearboxes. The accuracy, robustness and implementation of these methods have been examined by a comprehensive investigation, including theoretical studies of simple...... multi-modal beam systems and extensive experiments with more realistic small scale models and with large, detailed 3/4-scale test structures of a medium-size helicopter. In addition, partial verification tests have been conducted with the Eurocopter BK 117 helicopter and its main rotor gearbox....... The results of this work are essential as input for any prediction code of the internal noise in a helicopter cabin, because the prediction requires knowledge of the major sources, that is, the rotors, engines and gearboxes....

  9. A virtual infrastructure based on honeycomb tessellation for data dissemination in multi-sink mobile wireless sensor networks

    NARCIS (Netherlands)

    Erman-Tüysüz, A.; Dilo, Arta; Havinga, Paul J.M.

    2012-01-01

    A new category of intelligent sensor network applications emerges where motion is a fundamental characteristic of the system under consideration. In such applications, sensors are attached to vehicles, or people that move around large geographic areas. For instance, in mission critical applications

  10. Observing the Context of Use of a Media Player on Mobile Phones using Embedded and Virtual Sensors

    DEFF Research Database (Denmark)

    Larsen, Jakob Eg; Petersen, Michael Kai; Handler, Rasmus

    2010-01-01

    In this paper, we discuss how contextual data acquired from multiple embedded mobile phone sensors can provide insights into the mobile user experience. We report from two field studies where contextual information were obtained from N=21 mobile phone users in a 2–8 week duration, to derive infor...

  11. A haptic sensor-actor-system based on ultrasound elastography and electrorheological fluids for virtual reality applications in medicine.

    Science.gov (United States)

    Khaled, W; Ermert, H; Bruhns, O; Boese, H; Baumann, M; Monkman, G J; Egersdoerfer, S; Meier, A; Klein, D; Freimuth, H

    2003-01-01

    Mechanical properties of biological tissue represent important diagnostic information and are of histological relevance (hard lesions, "nodes" in organs: tumors; calcifications in vessels: arteriosclerosis). The problem is, that such information is usually obtained by digital palpation only, which is limited with respect to sensitivity. It requires intuitive assessment and does not allow quantitative documentation. A suitable sensor is required for quantitative detection of mechanical tissue properties. On the other hand, there is also some need for a realistic mechanical display of those tissue properties. Suitable actuator arrays with high spatial resolution and real-time capabilities are required operating in a haptic sensor actuator system with different applications. The sensor system uses real time ultrasonic elastography whereas the tactile actuator is based on electrorheological fluids. Due to their small size the actuator array elements have to be manufactured by micro-mechanical production methods. In order to supply the actuator elements with individual high voltages a sophisticated switching and control concept have been designed. This haptic system has the potential of inducing real time substantial forces, using a compact lightweight mechanism which can be applied to numerous areas including intraoperative navigation, telemedicine, teaching, space and telecommunication.

  12. Virtually teaching virtual leadership

    DEFF Research Database (Denmark)

    Henriksen, Thomas Duus; Nielsen, Rikke Kristine; Børgesen, Kenneth

    2018-01-01

    This paper seeks to investigate the challenges to virtual collaboration and leadership on basis of findings from a virtual course on collaboration and leadership. The course used for this experiment was designed as a practical approach, which allowed participants to experience curriculum phenomena....... This experimental course provided insights into the challenges involved in virtual processes, and those experiences where used for addressing the challenges that virtual leadership is confronted with. Emphasis was placed on the reduction of undesired virtual distance and its consequences through affinity building....... We found that student scepticism appeared when a breakdown resulted in increasing virtual distance, and raises questions on how leaders might translate or upgrade their understandings of leadership to handling such increased distance through affinity building....

  13. Self-directed arm therapy at home after stroke with a sensor-based virtual reality training system.

    Science.gov (United States)

    Wittmann, Frieder; Held, Jeremia P; Lambercy, Olivier; Starkey, Michelle L; Curt, Armin; Höver, Raphael; Gassert, Roger; Luft, Andreas R; Gonzenbach, Roman R

    2016-08-11

    The effect of rehabilitative training after stroke is dose-dependent. Out-patient rehabilitation training is often limited by transport logistics, financial resources and a lack of motivation/compliance. We studied the feasibility of an unsupervised arm therapy for self-directed rehabilitation therapy in patients' homes. An open-label, single group study involving eleven patients with hemiparesis due to stroke (27 ± 31.5 months post-stroke) was conducted. The patients trained with an inertial measurement unit (IMU)-based virtual reality system (ArmeoSenso) in their homes for six weeks. The self-selected dose of training with ArmeoSenso was the principal outcome measure whereas the Fugl-Meyer Assessment of the upper extremity (FMA-UE), the Wolf Motor Function Test (WMFT) and IMU-derived kinematic metrics were used to assess arm function, training intensity and trunk movement. Repeated measures one-way ANOVAs were used to assess differences in training duration and clinical scores over time. All subjects were able to use the system independently in their homes and no safety issues were reported. Patients trained on 26.5 ± 11.5 days out of 42 days for a duration of 137 ± 120 min per week. The weekly training duration did not change over the course of six weeks (p = 0.146). The arm function of these patients improved significantly by 4.1 points (p = 0.003) in the FMA-UE. Changes in the WMFT were not significant (p = 0.552). ArmeoSenso based metrics showed an improvement in arm function, a high number of reaching movements (387 per session), and minimal compensatory movements of the trunk while training. Self-directed home therapy with an IMU-based home therapy system is safe and can provide a high dose of rehabilitative therapy. The assessments integrated into the system allow daily therapy monitoring, difficulty adaptation and detection of maladaptive motor patterns such as trunk movements during reaching. Unique identifier: NCT02098135 .

  14. Organizaciones Virtuales Organizaciones Virtuales

    Directory of Open Access Journals (Sweden)

    Gladis Cecilia Villegas Arias

    2003-06-01

    Full Text Available Virtual Organizations are new organizational forms originated from both the replacementof face to face communications by remote communications supported by electronic means,and from the accesibility of real time information about the operation of the company, forall employees.This article pursues the following goals: 1 To define virtual organization, review its sociotechnical antecedents and propose a preliminary classification into inter-organizationaland intra-organizational forms.  2 To discuss the characteristics of virtual organizationsand their impact on organizational design, and 3 To compare virtual organizations toother organizational forms.Las organizaciones virtuales son formas organizativas nuevas, que resultan de: primero, reemplazar las interacciones cara a cara con interacciones remotas, soportadas por comunicaciones electrónicas y segundo,  proveer acceso en tiempo real a toda la información de la empresa para todos los trabajadores.En este artículo se busca: 1 Definir organización virtual, revisar sus antecedentes y proponeruna clasificación básica preliminar de las mismas  2 Discutir las características de las organizaciones virtuales y sus implicaciones para el diseño organizativo 3 Comparar estaforma organizativa a las formas organizativas no virtuales.

  15. Virtual colonoscopy

    Science.gov (United States)

    Colonoscopy - virtual; CT colonography; Computed tomographic colonography; Colography - virtual ... Differences between virtual and conventional colonoscopy include: VC can view the colon from many different angles. This is not as easy ...

  16. Virtual Interactive Space (VIS)

    DEFF Research Database (Denmark)

    Brooks, Anthony Lewis

    2015-01-01

    This paper shares code that enables the making of a Virtual Interactive Space (VIS) where the skin of the invisible active sensor area is dynamically responsive to the velocity of a limb e.g. hand. Used in proprioception training of movement the patch is at the core of the author’s Reafferentation...

  17. A fast vibro-acoustic response analysis method for double wall structures including a viscothermal air layer

    NARCIS (Netherlands)

    Basten, T.G.H.; Grooteman, F.P.

    2000-01-01

    The damping behaviour of a thin air layer between two flexible panels can be used to reduce sound radiation of structural excited panels. The numerical model of the double wall panels takes into account full acousto-elastic interaction and viscothermal wave propagation in the air layer. This means

  18. On the use of a variational technique based on integral equations for plane acoustic and vibro-acoustic problems

    DEFF Research Database (Denmark)

    Brunskog, Jonas; Richard, Antoine Philippe André

    2016-01-01

    Problems such as sound insulation and absorption of plane structures in laboratory conditions can theoretically be described as an integral or integral-differential equation. This equation contains the Green’s function integrated over the surface, which describes the radiation from the surface....... A variational technique, well described by Morse and Ingard, has successfully been used for both absorption and sound insulation for a plane incident wave. The resulting formulas are surprisingly simple, accurate and robust. Moreover, they capture the physics of sound radiation of a finite surface well. However...

  19. Vibro-acoustic topology optimization of sandwich panels partially treated with MR fluid and silicone rubber core layer

    Science.gov (United States)

    Hemmatian, Masoud; Sedaghati, Ramin

    2017-12-01

    This study aims to investigate the topology optimization of sandwich panels partially treated with magnetorheological (MR) fluid and silicone rubber core layer. The finite element (FE) model of the partially treated sandwich panel has been developed using circular and 4-node quadrilateral elements. The FE model is then utilized to solve the free and forced vibration equations of motion to obtain the natural frequencies, loss factors and sound transmission loss (STL), respectively. Systematic parametric studies on the effect of the position of the MR fluid and silicone rubber on the first axisymmetric natural frequency, the corresponding loss factor and also the STL are presented. It has been shown that the vibrational and acoustical behavior of the sandwich panel changes considerably as the location of the MR treatment changes. To conduct optimization problems efficiently without using the full FE model, linear meta-models have been derived using random and D-optimal design points. The developed meta-models are then utilized to solve the topology optimization problems using the genetic algorithm and integer programing methods. The suitability of the identified optimal candidates are further evaluated using the developed FE model to determine the optimized topology for the constraint and unconstraint problems.

  20. Virtual box

    DEFF Research Database (Denmark)

    Stougaard, Malthe Kirkhoff

    2007-01-01

    . This paper reports on the design, implementation and initial evaluation of Virtual Box. Virtual Box attempts to create a physical and engaging context in order to support reciprocal interactions with expressive content. An implemented version of Virtual Box is evaluated in a location-aware environment...

  1. Development of a Locomotion Interface for Portable Virtual Environment Systems Using an Inertial/Magnetic Sensor-Based System and a Ranging Measurement System

    Science.gov (United States)

    2014-03-01

    either unperceived or perceived as self-motion of the user, such as turning the head or rolling the eyes that is often done unintentionally in real...pp. 225‒240. [2] Shaleph O’Neill, “Presence, place and the virtual spectacle ,” PsychNology Journal, vol. 3, no. 2, 2005, pp. 149‒161. [3] Ioannis

  2. Virtual Instrumentation and Virtual Environments

    NARCIS (Netherlands)

    Spoelder, H.J.W.

    1999-01-01

    Instrumentation, interaction and virtual environments provide a challenging triplet for the next generation of instrumentation and measurement tools. As such, they are the logical continuation of an increasingly important component within (virtual) instrumentation. Despite these changes, however,

  3. Wireless virtualization

    CERN Document Server

    Wen, Heming; Le-Ngoc, Tho

    2013-01-01

    This SpringerBriefs is an overview of the emerging field of wireless access and mobile network virtualization. It provides a clear and relevant picture of the current virtualization trends in wireless technologies by summarizing and comparing different architectures, techniques and technologies applicable to a future virtualized wireless network infrastructure. The readers are exposed to a short walkthrough of the future Internet initiative and network virtualization technologies in order to understand the potential role of wireless virtualization in the broader context of next-generation ubiq

  4. Virtual marketing in virtual enterprises

    OpenAIRE

    Ale Ebrahim, Nader; Fattahi, Hamaid Ali; Golnam, Arash

    2008-01-01

    Virtualization caused tremendous evolution in the economics of marketing channels, patterns of physical distribution and the structure of distributors and developed a new concept that is known as virtual marketing (VM). VM combines the powerful technologies of interactive marketing and virtual reality. Virtual enterprise (VE) refers to an organization not having a clear physical locus. In other words, VE is an organization distributed geographically and whose work is coordinated through e...

  5. The Virtual Tablet: Virtual Reality as a Control System

    Science.gov (United States)

    Chronister, Andrew

    2016-01-01

    In the field of human-computer interaction, Augmented Reality (AR) and Virtual Reality (VR) have been rapidly growing areas of interest and concerted development effort thanks to both private and public research. At NASA, a number of groups have explored the possibilities afforded by AR and VR technology, among which is the IT Advanced Concepts Lab (ITACL). Within ITACL, the AVR (Augmented/Virtual Reality) Lab focuses on VR technology specifically for its use in command and control. Previous work in the AVR lab includes the Natural User Interface (NUI) project and the Virtual Control Panel (VCP) project, which created virtual three-dimensional interfaces that users could interact with while wearing a VR headset thanks to body- and hand-tracking technology. The Virtual Tablet (VT) project attempts to improve on these previous efforts by incorporating a physical surrogate which is mirrored in the virtual environment, mitigating issues with difficulty of visually determining the interface location and lack of tactile feedback discovered in the development of previous efforts. The physical surrogate takes the form of a handheld sheet of acrylic glass with several infrared-range reflective markers and a sensor package attached. Using the sensor package to track orientation and a motion-capture system to track the marker positions, a model of the surrogate is placed in the virtual environment at a position which corresponds with the real-world location relative to the user's VR Head Mounted Display (HMD). A set of control mechanisms is then projected onto the surface of the surrogate such that to the user, immersed in VR, the control interface appears to be attached to the object they are holding. The VT project was taken from an early stage where the sensor package, motion-capture system, and physical surrogate had been constructed or tested individually but not yet combined or incorporated into the virtual environment. My contribution was to combine the pieces of

  6. Virtual Congresses

    Science.gov (United States)

    Lecueder, Silvia; Manyari, Dante E.

    2000-01-01

    A new form of scientific medical meeting has emerged in the last few years—the virtual congress. This article describes the general role of computer technologies and the Internet in the development of this new means of scientific communication, by reviewing the history of “cyber sessions” in medical education and the rationale, methods, and initial results of the First Virtual Congress of Cardiology. Instructions on how to participate in this virtual congress, either actively or as an observer, are included. Current advantages and disadvantages of virtual congresses, their impact on the scientific community at large, and future developments and possibilities in this area are discussed. PMID:10641960

  7. Virtual Laboratories and Virtual Worlds

    Science.gov (United States)

    Hut, Piet

    2008-05-01

    Since we cannot put stars in a laboratory, astrophysicists had to wait till the invention of computers before becoming laboratory scientists. For half a century now, we have been conducting experiments in our virtual laboratories. However, we ourselves have remained behind the keyboard, with the screen of the monitor separating us from the world we are simulating. Recently, 3D on-line technology, developed first for games but now deployed in virtual worlds like Second Life, is beginning to make it possible for astrophysicists to enter their virtual labs themselves, in virtual form as avatars. This has several advantages, from new possibilities to explore the results of the simulations to a shared presence in a virtual lab with remote collaborators on different continents. I will report my experiences with the use of Qwaq Forums, a virtual world developed by a new company (see http://www.qwaq.com).

  8. Virtual Labs and Virtual Worlds

    Science.gov (United States)

    Boehler, Ted

    2006-12-01

    Virtual Labs and Virtual Worlds Coastline Community College has under development several virtual lab simulations and activities that range from biology, to language labs, to virtual discussion environments. Imagine a virtual world that students enter online, by logging onto their computer from home or anywhere they have web access. Upon entering this world they select a personalized identity represented by a digitized character (avatar) that can freely move about, interact with the environment, and communicate with other characters. In these virtual worlds, buildings, gathering places, conference rooms, labs, science rooms, and a variety of other “real world” elements are evident. When characters move about and encounter other people (players) they may freely communicate. They can examine things, manipulate objects, read signs, watch video clips, hear sounds, and jump to other locations. Goals of critical thinking, social interaction, peer collaboration, group support, and enhanced learning can be achieved in surprising new ways with this innovative approach to peer-to-peer communication in a virtual discussion world. In this presentation, short demos will be given of several online learning environments including a virtual biology lab, a marine science module, a Spanish lab, and a virtual discussion world. Coastline College has been a leader in the development of distance learning and media-based education for nearly 30 years and currently offers courses through PDA, Internet, DVD, CD-ROM, TV, and Videoconferencing technologies. Its distance learning program serves over 20,000 students every year. sponsor Jerry Meisner

  9. Virtual Acoustics

    Science.gov (United States)

    Lokki, Tapio; Savioja, Lauri

    The term virtual acoustics is often applied when sound signal is processed to contain features of a simulated acoustical space and sound is spatially reproduced either with binaural or with multichannel techniques. Therefore, virtual acoustics consists of spatial sound reproduction and room acoustics modeling.

  10. Virtual projects

    DEFF Research Database (Denmark)

    Svejvig, Per; Commisso, Trine Hald

    2012-01-01

    Virtual projects are common with global competition, market development, and not least the financial crisis forcing organizations to reduce their costs drastically. Organizations therefore have to place high importance on ways to carry out virtual projects and consider appropriate practices...... for performing these projects. This paper compares best practices with practiced practices for virtual projects and discusses ways to bridge the gap between them. We have studied eleven virtual projects in five Danish organizations and compared them with a predefined list of best practices compiled from...... that the best practice knowledge has not permeated sufficiently to the practice. Furthermore, the appropriate application of information and communication technology (ICT) remains a big challenge, and finally project managers are not sufficiently trained in organizing and conducting virtual projects...

  11. Virtual Exploratories

    DEFF Research Database (Denmark)

    Jensen, Sisse Siggaard

    2006-01-01

    This paper proposes the notion of activity-systems to denote a virtual frame of activity that requires mutually coordinated action. The underlying assumption is that such framings may support the informal learning and reflective practices of actors, and especially so, when they are provoking...... and challenging. It is suggested that the prevailing ‘traditions’ of collaborative learning and knowledge sharing need to be challenged and complemented, if we are to be able to support the variety and the diversity in the repertoires of virtual learning activities. In order to conceptualize such activity......-systems, the paper introduces the designing strategy referred to as virtual exploratories. Some of the advanced virtual worlds may inspire the design of such provoking and challenging virtual exploratories, and especially the Massively Multi-User Online Role-Playing Games (MMORPGS). However, if we have to learn from...

  12. A Virtual Tour of Virtual Schools.

    Science.gov (United States)

    Joiner, Lottie L.

    2002-01-01

    Briefly describes the eight virtual schools in the United States: Kentucky Virtual High School; Illinois Virtual High School; Florida Virtual School; CCS Web Academy in Fayetteville, North Carolina; The Virtual High School in Hudson, Massachusetts; Basehor-Linwood Virtual Charter School in Kansas; Monte Vista Online Academy in Colorado; and…

  13. Virtual Globe Games for Geographic Learning

    Directory of Open Access Journals (Sweden)

    Ola Ahlqvist

    2010-02-01

    Full Text Available Virtual, online maps and globes allow for volunteered geographic information to capitalize on users as sensors and generate unprecedented access to information resources and services. These new "Web 2.0" applications will probably dominate development and use of virtual globes and maps in the near future. We present an experimental platform that integrates an existing virtual globe interface with added functionality as follows; an interactive layer on top of the existing map that support real time creation and manipulation of spatial interaction objects. These objects, together with the existing information delivered through the virtual globe, form a game board that can be used for educational purposes.

  14. Virtual Reality

    Directory of Open Access Journals (Sweden)

    Dan L. Lacrãmã

    2007-01-01

    Full Text Available This paper is focused on the presentation of Virtual Reality principles together with the main implementation methods and techniques. An overview of the main development directions is included.

  15. Virtual Savannah

    DEFF Research Database (Denmark)

    Eskildsen, Søren; Rodil, Kasper; Rehm, Matthias

    2012-01-01

    It is a daunting task to visualize square kilometers of African savannah and currently in zoos it is impossible to present true African ecology to visitors. Virtual Savannah is a dynamic virtual world that introduces school children to a 3D representation of the wildlife sanctuaries Serengeti...... and Masai Mara. The objective is to substitute supplementary textual information currently used in schools and provide the teacher with information about each pupil. The Virtual Savannah was tested in situ on 19 pupils age 10-11 with the purpose of logging all interaction with animals, GUI...... and the navigation. The test depicted how they managed to search the virtual world for answers in patterns related to restrictions in the system and using graphical points of interest as reference points. Collecting information about the complete interaction provides teachers with a tool to assess the individual...

  16. Virtual care

    DEFF Research Database (Denmark)

    Kamp, Annette; Aaløkke Ballegaard, Stinne

    of retrenchment, promising better quality, empowerment of citizens and work that is smarter and more qualified. Through ethnographic field studies we study the introduction of virtual home care in Danish elderly care, focusing on the implications for relational work and care relations. Virtual home care entails...... and professionals, and they instigate change in organization and professional identities. Studies, which more specifically deal with telecare, stress how virtualization alters the character of the observations care workers are able to make, and how the validity of the patients’ own measurements and observations...... point out how issues of trust and surveillance, which are always negotiated in care relations, are in fact accentuated in this kind of virtual care work. Moreover, we stress that the contemporary institutional context, organization and time schedules have a vast impact on the practices developed....

  17. Virtual Workshop

    DEFF Research Database (Denmark)

    Buus, Lillian; Bygholm, Ann

    In relation to the Tutor course in the Mediterranean Virtual University (MVU) project, a virtual workshop “Getting experiences with different synchronous communication media, collaboration, and group work” was held with all partner institutions in January 2006. More than 25 key-tutors within MVU...... participated from different institutions in the workshop. The result of the workshop was experiences with different communication tools and media. Facing the difficulties and possibilities in collaborateting virtually concerned around group work and development of a shared presentation. All based on getting...... experiences for the learning design of MVU courses. The workshop intented to give the participants the possibility to draw their own experiences with issues on computer supported collaboration, group work in a virtual environment, synchronous and asynchronous communication media, and different perspectives...

  18. Virtual Worlds for Virtual Organizing

    Science.gov (United States)

    Rhoten, Diana; Lutters, Wayne

    The members and resources of a virtual organization are dispersed across time and space, yet they function as a coherent entity through the use of technologies, networks, and alliances. As virtual organizations proliferate and become increasingly important in society, many may exploit the technical architecture s of virtual worlds, which are the confluence of computer-mediated communication, telepresence, and virtual reality originally created for gaming. A brief socio-technical history describes their early origins and the waves of progress followed by stasis that brought us to the current period of renewed enthusiasm. Examination of contemporary examples demonstrates how three genres of virtual worlds have enabled new arenas for virtual organizing: developer-defined closed worlds, user-modifiable quasi-open worlds, and user-generated open worlds. Among expected future trends are an increase in collaboration born virtually rather than imported from existing organizations, a tension between high-fidelity recreations of the physical world and hyper-stylized imaginations of fantasy worlds, and the growth of specialized worlds optimized for particular sectors, companies, or cultures.

  19. Virtual DRI dataset development

    Science.gov (United States)

    Hixson, Jonathan G.; Teaney, Brian P.; May, Christopher; Maurer, Tana; Nelson, Michael B.; Pham, Justin R.

    2017-05-01

    The U.S. Army RDECOM CERDEC NVESD MSD's target acquisition models have been used for many years by the military analysis community for sensor design, trade studies, and field performance prediction. This paper analyzes the results of perception tests performed to compare the results of a field DRI (Detection, Recognition, and Identification Test) performed in 2009 to current Soldier performance viewing the same imagery in a laboratory environment and simulated imagery of the same data set. The purpose of the experiment is to build a robust data set for use in the virtual prototyping of infrared sensors. This data set will provide a strong foundation relating, model predictions, field DRI results and simulated imagery.

  20. Virtual Specimens

    Science.gov (United States)

    de Paor, D. G.

    2009-12-01

    Virtual Field Trips have been around almost as long as the Worldwide Web itself yet virtual explorers do not generally return to their desktops with folders full of virtual hand specimens. Collection of real specimens on fields trips for later analysis in the lab (or at least in the pub) has been an important part of classical field geoscience education and research for generations but concern for the landscape and for preservation of key outcrops from wanton destruction has lead to many restrictions. One of the author’s favorite outcrops was recently vandalized presumably by a geologist who felt the need to bash some of the world’s most spectacular buckle folds with a rock sledge. It is not surprising, therefore, that geologists sometimes leave fragile localities out of field trip itineraries. Once analyzed, most specimens repose in drawers or bins, never to be seen again. Some end up in teaching collections but recent pedagogical research shows that undergraduate students have difficulty relating specimens both to their collection location and ultimate provenance in the lithosphere. Virtual specimens can be created using 3D modeling software and imported into virtual globes such as Google Earth (GE) where, they may be linked to virtual field trip stops or restored to their source localities on the paleo-globe. Sensitive localities may be protected by placemark approximation. The GE application program interface (API) has a distinct advantage over the stand-alone GE application when it comes to viewing and manipulating virtual specimens. When instances of the virtual globe are embedded in web pages using the GE plug-in, Collada models of specimens can be manipulated with javascript controls residing in the enclosing HTML, permitting specimens to be magnified, rotated in 3D, and sliced. Associated analytical data may be linked into javascript and localities for comparison at various points on the globe referenced by ‘fetching’ KML. Virtual specimens open up

  1. Virtual Violence.

    Science.gov (United States)

    2016-08-01

    In the United States, exposure to media violence is becoming an inescapable component of children's lives. With the rise in new technologies, such as tablets and new gaming platforms, children and adolescents increasingly are exposed to what is known as "virtual violence." This form of violence is not experienced physically; rather, it is experienced in realistic ways via new technology and ever more intense and realistic games. The American Academy of Pediatrics continues to be concerned about children's exposure to virtual violence and the effect it has on their overall health and well-being. This policy statement aims to summarize the current state of scientific knowledge regarding the effects of virtual violence on children's attitudes and behaviors and to make specific recommendations for pediatricians, parents, industry, and policy makers. Copyright © 2016 by the American Academy of Pediatrics.

  2. Virtual Sustainability

    Directory of Open Access Journals (Sweden)

    William Sims Bainbridge

    2010-09-01

    Full Text Available In four ways, massively multiplayer online role-playing games may serve as tools for advancing sustainability goals, and as laboratories for developing alternatives to current social arrangements that have implications for the natural environment. First, by moving conspicuous consumption and other usually costly status competitions into virtual environments, these virtual worlds might reduce the need for physical resources. Second, they provide training that could prepare individuals to be teleworkers, and develop or demonstrate methods for using information technology to replace much transportation technology, notably in commuting. Third, virtual worlds and online games build international cooperation, even blending national cultures, thereby inching us toward not only the world consciousness needed for international agreements about the environment, but also toward non-spatial government that cuts across archaic nationalisms. Finally, realizing the potential social benefits of this new technology may urge us to reconsider a number of traditional societal institutions.

  3. Virtual Touch

    DEFF Research Database (Denmark)

    Stenslie, Ståle

    Erotogod. The third chapter investigates the foundations of touch through a physiological and psychological approach. Chapter four presents an alternative haptic history of Virtual Realities through the presentation and discussion of several technological and artistic works that are computer...... is the analysis and conclusion of my experiments. The problems addressed concern how it feels to touch and be touched in multimodal environments, or so called Virtual Realities. Firstly how haptic, corporeal interaction influence the overall experience of a given interactive human-to-computer system. Secondly...... and the psychophysically-contextualized work of art The main results and applications of the study are firstly that haptic technologies bridge the gap between the real (corporeal) and the virtual (immaterial) world, supporting the assumption that the distinction between the ‘virtual’ and the ‘real’ is not convincing...

  4. Virtual Learning

    Science.gov (United States)

    Cvetkovic, Dragan, Ed.

    2016-01-01

    The first chapter provides an overview of the popular systems for distance learning. In the second chapter, a review of all major social and economic activities in order to improve the system of virtual learning is given. The third chapter deals with the influence of technology in the management of educational institutions. The fourth chapter…

  5. Virtual modeling

    NARCIS (Netherlands)

    Flores, J.; Kiss, S.; Cano, P.; Nijholt, Antinus; Zwiers, Jakob

    2003-01-01

    We concentrate our efforts on building virtual modelling environments where the content creator uses controls (widgets) as an interactive adjustment modality for the properties of the edited objects. Besides the advantage of being an on-line modelling approach (visualised just like any other on-line

  6. Virtual Reality.

    Science.gov (United States)

    Newby, Gregory B.

    1993-01-01

    Discusses the current state of the art in virtual reality (VR), its historical background, and future possibilities. Highlights include applications in medicine, art and entertainment, science, business, and telerobotics; and VR for information science, including graphical display of bibliographic data, libraries and books, and cyberspace.…

  7. Virtual landmarks

    Science.gov (United States)

    Tong, Yubing; Udupa, Jayaram K.; Odhner, Dewey; Bai, Peirui; Torigian, Drew A.

    2017-03-01

    Much has been published on finding landmarks on object surfaces in the context of shape modeling. While this is still an open problem, many of the challenges of past approaches can be overcome by removing the restriction that landmarks must be on the object surface. The virtual landmarks we propose may reside inside, on the boundary of, or outside the object and are tethered to the object. Our solution is straightforward, simple, and recursive in nature, proceeding from global features initially to local features in later levels to detect landmarks. Principal component analysis (PCA) is used as an engine to recursively subdivide the object region. The object itself may be represented in binary or fuzzy form or with gray values. The method is illustrated in 3D space (although it generalizes readily to spaces of any dimensionality) on four objects (liver, trachea and bronchi, and outer boundaries of left and right lungs along pleura) derived from 5 patient computed tomography (CT) image data sets of the thorax and abdomen. The virtual landmark identification approach seems to work well on different structures in different subjects and seems to detect landmarks that are homologously located in different samples of the same object. The approach guarantees that virtual landmarks are invariant to translation, scaling, and rotation of the object/image. Landmarking techniques are fundamental for many computer vision and image processing applications, and we are currently exploring the use virtual landmarks in automatic anatomy recognition and object analytics.

  8. Virtual Classroom

    DEFF Research Database (Denmark)

    Christensen, Ove

    2013-01-01

    In the Scandinavian countries: Sweden, Norway and Denmark, the project GNU (Grænseoverskridende Nordisk Undervisning, i.e. Transnational Nordic Teaching) is experimenting with ways of conducting teaching across the borders in the elementary schools. The cloud classes are organised with one class ...... and benefits in regard to learning and pedagogy with virtual classroom....

  9. Virtualize Me!

    Science.gov (United States)

    Waters, John K.

    2009-01-01

    John Abdelmalak, director of technology for the School District of the Chathams, was pretty sure it was time to jump on the virtualization bandwagon last year when he invited Dell to conduct a readiness assessment of his district's servers. When he saw just how little of their capacity was being used, he lost all doubt. Abdelmalak is one of many…

  10. Virtual Savannah

    DEFF Research Database (Denmark)

    Rodil, Kasper; Eskildsen, Søren; Rehm, Matthias

    2012-01-01

    Virtual Savannah is constructed to visualize parts of a curriculum, which the educational service at Aalborg Zoo has difficulties in teaching children visiting the zoo. It contains rich media like audio, text, video and picture galleries about African ecology, but some of this episodic information...

  11. Virtual patrolling

    NARCIS (Netherlands)

    van der Vlist, M.; Wismans, Luc Johannes Josephus; van Beek, P.; Suijs, L.C.W.

    2016-01-01

    Approximately 25 per cent of all congestion on motorways is caused by incidents. By virtual patrolling, incidents e.g. queues, accidents and car breakdowns on a road network, can be predicted or detected in an early stage. This early detection and prediction of an incident likely to happen, offers

  12. Virtual patrolling.

    NARCIS (Netherlands)

    van der Vlist, M.; Wismans, Luc Johannes Josephus; van Beek, P.; Suijs, L.C.W.

    2016-01-01

    Approximately 25 per cent of all congestion on motorways is caused by incidents. By virtual patrolling, incidents e.g. queues, accidents and car breakdowns on a road network, can be predicted or detected in an early stage. This early detection and prediction of an incident likely to happen, offers

  13. Virtual Presenters: Towards Interactive Virtual Presentations

    NARCIS (Netherlands)

    Nijholt, Antinus; Cappellini, V.; Hemsley, J.

    2005-01-01

    We discuss having virtual presenters in virtual environments that present information to visitors of these environments. Some current research is surveyed and we will look in particular to our research in the context of a virtual meeting room where a virtual presenter uses speech, gestures, pointing

  14. Sensorial Virtualization: Coupling Gaming and Virtual Environment

    NARCIS (Netherlands)

    Garbaya, S.; Miraoui, C.; Wendrich, Robert E.; Lim, T.; Stanescu, I.A.; Hauge, J.B.

    2014-01-01

    Virtual reality and virtualization are currently used to design complex systems and demonstrate that they represent the functionalities of real systems. However, the design refinement of the virtual environment (VE) and distributed virtual environment (DVE) are still time consuming and costly, as it

  15. Sensors on speaking terms: Schedule-based medium access control protocols for wireless sensor networks

    NARCIS (Netherlands)

    van Hoesel, L.F.W.

    2007-01-01

    Wireless sensor networks make the previously unobservable, observable. The basic idea behind these networks is straightforward: all wires are cut in traditional sensing systems and the sensors are equipped with batteries and radio's to virtually restore the cut wires. The resulting sensors can be

  16. Virtual anthropology.

    Science.gov (United States)

    Weber, Gerhard W

    2015-02-01

    Comparative morphology, dealing with the diversity of form and shape, and functional morphology, the study of the relationship between the structure and the function of an organism's parts, are both important subdisciplines in biological research. Virtual anthropology (VA) contributes to comparative morphology by taking advantage of technological innovations, and it also offers new opportunities for functional analyses. It exploits digital technologies and pools experts from different domains such as anthropology, primatology, medicine, paleontology, mathematics, statistics, computer science, and engineering. VA as a technical term was coined in the late 1990s from the perspective of anthropologists with the intent of being mostly applied to biological questions concerning recent and fossil hominoids. More generally, however, there are advanced methods to study shape and size or to manipulate data digitally suitable for application to all kinds of primates, mammals, other vertebrates, and invertebrates or to issues regarding plants, tools, or other objects. In this sense, we could also call the field "virtual morphology." The approach yields permanently available virtual copies of specimens and data that comprehensively quantify geometry, including previously neglected anatomical regions. It applies advanced statistical methods, supports the reconstruction of specimens based on reproducible manipulations, and promotes the acquisition of larger samples by data sharing via electronic archives. Finally, it can help identify new, hidden traits, which is particularly important in paleoanthropology, where the scarcity of material demands extracting information from fragmentary remains. This contribution presents a current view of the six main work steps of VA: digitize, expose, compare, reconstruct, materialize, and share. The VA machinery has also been successfully used in biomechanical studies which simulate the stress and strains appearing in structures. Although

  17. Virtual Goods Recommendations in Virtual Worlds

    OpenAIRE

    Kuan-Yu Chen; Hsiu-Yu Liao; Jyun-Hung Chen; Duen-Ren Liu

    2015-01-01

    Virtual worlds (VWs) are computer-simulated environments which allow users to create their own virtual character as an avatar. With the rapidly growing user volume in VWs, platform providers launch virtual goods in haste and stampede users to increase sales revenue. However, the rapidity of development incurs virtual unrelated items which will be difficult to remarket. It not only wastes virtual global companies’ intelligence resources, but also makes it difficult for users to find suitable v...

  18. Virtual Proprioception for eccentric training.

    Science.gov (United States)

    LeMoyne, Robert; Mastroianni, Timothy

    2017-07-01

    Wireless inertial sensors enable quantified feedback, which can be applied to evaluate the efficacy of therapy and rehabilitation. In particular eccentric training promotes a beneficial rehabilitation and strength training strategy. Virtual Proprioception for eccentric training applies real-time feedback from a wireless gyroscope platform enabled through a software application for a smartphone. Virtual Proprioception for eccentric training is applied to the eccentric phase of a biceps brachii strength training and contrasted to a biceps brachii strength training scenario without feedback. During the operation of Virtual Proprioception for eccentric training the intent is to not exceed a prescribed gyroscope signal threshold based on the real-time presentation of the gyroscope signal, in order to promote the eccentric aspect of the strength training endeavor. The experimental trial data is transmitted wireless through connectivity to the Internet as an email attachment for remote post-processing. A feature set is derived from the gyroscope signal for machine learning classification of the two scenarios of Virtual Proprioception real-time feedback for eccentric training and eccentric training without feedback. Considerable classification accuracy is achieved through the application of a multilayer perceptron neural network for distinguishing between the Virtual Proprioception real-time feedback for eccentric training and eccentric training without feedback.

  19. Augmented Virtual Reality Laboratory

    Science.gov (United States)

    Tully-Hanson, Benjamin

    2015-01-01

    Real time motion tracking hardware has for the most part been cost prohibitive for research to regularly take place until recently. With the release of the Microsoft Kinect in November 2010, researchers now have access to a device that for a few hundred dollars is capable of providing redgreenblue (RGB), depth, and skeleton data. It is also capable of tracking multiple people in real time. For its original intended purposes, i.e. gaming, being used with the Xbox 360 and eventually Xbox One, it performs quite well. However, researchers soon found that although the sensor is versatile, it has limitations in real world applications. I was brought aboard this summer by William Little in the Augmented Virtual Reality (AVR) Lab at Kennedy Space Center to find solutions to these limitations.

  20. Tangible interfaces in virtual environments, case study: Instituto de Engenharia Nuclear Virtual

    Energy Technology Data Exchange (ETDEWEB)

    Santo, Andre Cotelli do E.; Mol, Antonio Carlos A.; Pinto, Emanuele Oliveira; Melo, Joao Victor da C.; Paula, Vanessa Marcia de; Freitas, Victor Goncalves Gloria [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Machado, Daniel Mol [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Instituto Alberto Luiz Coimbra

    2015-07-01

    Virtual Reality (VR) techniques allow the creation of realistic representations of an individual. These technologies are being applied in several fields such as training, simulations, virtual experiments and new applications are constantly being found. This work aims to present an interactive system in virtual environments without the use of peripherals typically found in computers such as mouse and keyboard. Through the movement of head and hands it is possible to control and navigate the virtual character (avatar) in a virtual environment, an improvement in the man-machine integration. The head movements are recognized using a virtual helmet with a tracking system. An infrared camera detects the position of infrared LEDs located in the operator's head and places the vision of the virtual character in accordance with the operator's vision. The avatar control is performed by a system that detects the movement of the hands, using infrared sensors, allowing the user to move it in the virtual environment. This interaction system was implemented in the virtual model of the Instituto de Engenharia Nuclear (IEN), which is located on the Ilha do Fundao - Rio de Janeiro - Brazil. This three-dimensional environment, in which avatars can move and interact according to the user movements, gives a feeling of realism to the operator. The results show an interface that allows a higher degree of immersion of the operator in the virtual environment, promoting a more engaging and dynamic way of working. (author)

  1. Virtual simulation tools for artillery

    Science.gov (United States)

    Gozard, Patrick; Bret, Emmanuel; Cathala, Thierry

    2008-04-01

    To perform multi-sensors simulations, the French DGA/DET (Directorate for Technical Evaluation of the French Ministry of Defense) uses CHORALE (simulated Optronic Acoustic Radar battlefield). CHORALE enables the user to create virtual and realistic multi spectral 3D scenes, and generates the physical signal received by one or several sensors, typically an IR sensor or an acoustic sensor. This article presents different kinds of scenario such as desert, urban, campaign place to evaluate intelligent artillery ammunition. The ammunition described has to detect thermal contrast above a target area for the detection capability and firing decision. The scene is as realistic as possible to give to french army good parameters according to their request in a typical operational scenario. That includes background with trees, houses, roads, fields, targets, dunes, with different materials such as grass, sand, rock, wood, concrete... All object in the 3D scene is characterized by optronic parameters used by CHORALE Workbench. The signal provided by this workbench is adapted by AMOCO workbench which allows defining sensor technology. Then a process unit provides the firing decision and the lethality data from the target which has been reached. Each tool is explained to understand the physics phenomena in the scene to take into account atmospheric transmission, radiative parameters of objects and counter-measure devices. Finally, this paper shows results by coupling the operational scenario with sensor model to do a global simulation in order to determine global performances of artillery ammunition.

  2. Periodismo virtual

    Directory of Open Access Journals (Sweden)

    Carlos Morales

    2015-01-01

    Full Text Available El periodismo virtual se produce en diarios que no ofrecen noticias (concebidas como versión o reflejo de la realidad sino que crean sus propias ficciones, especialmente en primeras planas. El autor del artículo señala que esto esta sucediendo en LA NACIÓN de San José de Costa Rica, diario premiado por la inefable Sociedad Interamericana de Prensa - SIP - y periódico económicamente más importante del país.

  3. Virtual Sensors: Efficiently Estimating Missing Spectra

    Data.gov (United States)

    National Aeronautics and Space Administration — Various instruments are used to create images of the Earth and other objects in the universe in a diverse set of wavelength bands with the aim of understanding...

  4. Virtual sensors for advanced vehicle stability control

    NARCIS (Netherlands)

    Leenen, R.; Schouten, H.

    2010-01-01

    Advanced vehicle control technologies provide a great potential to further improve vehicle handling, ride and safety. The goal of this research is to demonstrate the added value of the TNO Vehicle State Estimation module to integrated active safety. State-of-the-art Electronic Stability Control

  5. Sensors for the Senses

    DEFF Research Database (Denmark)

    Brooks, Anthony Lewis

    2015-01-01

    -worn sensors (volumetric, linear and planar interface profiles). Mapping of sourced human data is to a variety of digital content including art-based (music making, digital painting, lighting effects), video games, Virtual Reality and robotic devices. System adaptability promotes participant profile matching e...... product and industry start-ups. At the core of the research is a rethinking in the way a human interacts with ICT. Current research explores a concept of dynamic air and alternative physical-virtual environments. Conclusions introduce a suggested need of increased researcher awareness of post......In his ACM Computers in Entertainment article, titled "Artist and Audience: Emerging the Nano-entertainment experience", the author posited on how Inhabited Information Spaces, created as core catalyst of research, may be questioned as a multisensory future virtual work of art. This themed Human...

  6. Trust and virtual worlds

    DEFF Research Database (Denmark)

    Ess, Charles; Thorseth, May

    2011-01-01

    We collect diverse philosophical analyses of the issues and problems clustering around trust online with specific attention to establishing trust in virtual environments. The book moves forward important discussions of how virtual worlds and virtuality are to be defined and understood; the role...... by virtuality, such as virtual child pornography. The introduction further develops a philosophical anthropology, rooted in Kantian ethics, phenomenology, virtue ethics, and feminist perspectives, that grounds a specific approach to ethical issues in virtual environments....

  7. Virtual screening of virtual libraries.

    Science.gov (United States)

    Green, Darren V S

    2003-01-01

    Virtual screening of virtual libraries (VSVL) is a rapidly changing area of research. Great efforts are being made to produce better algorithms, selection methods and infrastructure. Yet, the number of successful examples in the literature is not impressive, although the quality of work certainly is high. Why is this? One reason is that these methods tend to be applied at the lead generation stage and therefore there is a large lead-time before successful examples appear in the literature. However, any computational chemist would confirm that these methods are successful and there exists a glut of start-up companies specialising in virtual screening. Moreover, the scientific community would not be focussing so much attention on this area if it were not yielding results. Even so, the paucity of literature data is certainly a hindrance to the development of better methods. The VSVL process is unique within the discovery process, in that it is the only method that can screen the > 10(30) genuinely novel molecules out there. Already, some VSVL methods are evaluating 10(13) compounds, a capacity that high throughput screening can only dream of. There is a huge potential advantage for the company that develops efficient and effective methods, for lead generation, lead hopping and optimization of both potency and ADME properties. To do this, it requires more than the software, it requires confidence to exploit the methodology, to commit synthesis on the basis of it, and to build this approach into the medicinal chemistry strategy. It is a fact that these tools remain quite daunting for the majority of scientists working at the bench. The routine use of these methods is not simply a matter of education and training. Integration of these methods into accessible and robust end user software, without dilution of the science, must be a priority. We have reached a coincidence, where several technologies have the required level of maturity predictive computational chemistry

  8. Development of Intelligent Controller with Virtual Sensing

    Directory of Open Access Journals (Sweden)

    Yul Y. Nazaruddin

    2009-05-01

    Full Text Available In many industrial plants, some key variables cannot always be measured on-line and for the purpose of control, an alternative of sensing system is required. This paper is concerned with a development of an alternative intelligent control strategy, which is an integration between the neuro-fuzzy based controller and virtual sensing system. This allows an immeasurable variable to be inferred and used for control. The virtual sensor is composed of the Diagonal Recurrent Neural Network (DRNN for plant modeling and the Extended Kalman Filter (EKF as the estimator with inputs from DRNN. The integration between virtual sensor and the controller enables a development of an on-line control scheme involving the immeasurable variable. The real-time implementation demonstrates the applicability and the performance of the proposed intelligent control scheme, especially in dealing with nonlinear processes.

  9. Realidad virtual y materialidad

    OpenAIRE

    Pérez Herranz, Fernando Miguel

    2009-01-01

    1. Fenomenología de partida: Real / Simbólico / Imaginario 2. Realidad 3. Virtual 3.1. Virtual / real / posible / probable 3.2. Los contextos de la realidad virtual A) REALIDAD VIRTUAL INMERSIVA B) REALIDAD VIRTUAL NO INMERSIVA C) REALIDAD VIRTUAL Y DIGITALIZACIÓN 3.3. Cruce virtual / real 3.4. Cuestiones filosóficas 4. Materialidad 5. Materialidad y descentramiento 5.1. Ejemplos de descentramiento en los contextos de Realidad Virtual A’) DUALISMO CARTESIANO, CUERPO Y «CIBORG » B’) EL ESPÍRIT...

  10. Virtual Estimator for Piecewise Linear Systems Based on Observability Analysis

    Science.gov (United States)

    Morales-Morales, Cornelio; Adam-Medina, Manuel; Cervantes, Ilse; Vela-Valdés and, Luis G.; García Beltrán, Carlos Daniel

    2013-01-01

    This article proposes a virtual sensor for piecewise linear systems based on observability analysis that is in function of a commutation law related with the system's outpu. This virtual sensor is also known as a state estimator. Besides, it presents a detector of active mode when the commutation sequences of each linear subsystem are arbitrary and unknown. For the previous, this article proposes a set of virtual estimators that discern the commutation paths of the system and allow estimating their output. In this work a methodology in order to test the observability for piecewise linear systems with discrete time is proposed. An academic example is presented to show the obtained results. PMID:23447007

  11. Minimizing Input-to-Output Latency in Virtual Environment

    Science.gov (United States)

    Adelstein, Bernard D.; Ellis, Stephen R.; Hill, Michael I.

    2009-01-01

    A method and apparatus were developed to minimize latency (time delay ) in virtual environment (VE) and other discrete- time computer-base d systems that require real-time display in response to sensor input s. Latency in such systems is due to the sum of the finite time requi red for information processing and communication within and between sensors, software, and displays.

  12. Microsoft Virtualization Master Microsoft Server, Desktop, Application, and Presentation Virtualization

    CERN Document Server

    Olzak, Thomas; Boomer, Jason; Keefer, Robert M

    2010-01-01

    Microsoft Virtualization helps you understand and implement the latest virtualization strategies available with Microsoft products. This book focuses on: Server Virtualization, Desktop Virtualization, Application Virtualization, and Presentation Virtualization. Whether you are managing Hyper-V, implementing desktop virtualization, or even migrating virtual machines, this book is packed with coverage on all aspects of these processes. Written by a talented team of Microsoft MVPs, Microsoft Virtualization is the leading resource for a full installation, migration, or integration of virtual syste

  13. REASONS FOR CHOOSING TEST – OPERATION SETTING FOR VIBRO - ACOUSTICAL METHOD OF TEST-OPERATION CONCRETE POLES IN THE OVERHEAD SYSTEM

    Directory of Open Access Journals (Sweden)

    V. H. Kuznetsov

    2010-11-01

    Full Text Available The scientific substantiation of a selection of diagnostic parameter for a new method of diagnostics of ferroconcrete supports of an electric-traction network on the basis of the average information on a support condition is conducted.

  14. A vibro-acoustical and perceptive Study of the neck-to-body Junction of a solid-body electric Guitar

    OpenAIRE

    Paté, Arthur; Le Carrou, Jean-Loic; Navarret, Benoît; Dubois, Danièle; Fabre, Benoit

    2012-01-01

    International audience; The string motion of the solid body electric guitar is captured by an electromagnetic transducer sending an electrical signal to an amplification system, providing the sound to be perceived. Transducer and amplification have been so far well investigated, but the vibrational aspect of the instrument in connection with lutherie has been rarely considered. The aim of the present study is to analyse mechanically and perceptually the own influence of a single construction ...

  15. Human-computer interface glove using flexible piezoelectric sensors

    Science.gov (United States)

    Cha, Youngsu; Seo, Jeonggyu; Kim, Jun-Sik; Park, Jung-Min

    2017-05-01

    In this note, we propose a human-computer interface glove based on flexible piezoelectric sensors. We select polyvinylidene fluoride as the piezoelectric material for the sensors because of advantages such as a steady piezoelectric characteristic and good flexibility. The sensors are installed in a fabric glove by means of pockets and Velcro bands. We detect changes in the angles of the finger joints from the outputs of the sensors, and use them for controlling a virtual hand that is utilized in virtual object manipulation. To assess the sensing ability of the piezoelectric sensors, we compare the processed angles from the sensor outputs with the real angles from a camera recoding. With good agreement between the processed and real angles, we successfully demonstrate the user interaction system with the virtual hand and interface glove based on the flexible piezoelectric sensors, for four hand motions: fist clenching, pinching, touching, and grasping.

  16. Virtual reality - aesthetic consequences

    OpenAIRE

    Benda, Lubor

    2013-01-01

    In the present work we study aesthetic consequences of virtual reality. Exploring the fringe between fictional and virtual is one of the key goals, that will be achieved through etymologic and technologic definition of both fiction and virtual reality, fictional and virtual worlds. Both fiction and virtual reality will be then studied from aesthetic distance and aesthetic pleasure point of view. At the end, we will see the main difference as well as an common grounds between fiction and virtu...

  17. Virtual Goods Recommendations in Virtual Worlds

    Directory of Open Access Journals (Sweden)

    Kuan-Yu Chen

    2015-01-01

    Full Text Available Virtual worlds (VWs are computer-simulated environments which allow users to create their own virtual character as an avatar. With the rapidly growing user volume in VWs, platform providers launch virtual goods in haste and stampede users to increase sales revenue. However, the rapidity of development incurs virtual unrelated items which will be difficult to remarket. It not only wastes virtual global companies’ intelligence resources, but also makes it difficult for users to find suitable virtual goods fit for their virtual home in daily virtual life. In the VWs, users decorate their houses, visit others’ homes, create families, host parties, and so forth. Users establish their social life circles through these activities. This research proposes a novel virtual goods recommendation method based on these social interactions. The contact strength and contact influence result from interactions with social neighbors and influence users’ buying intention. Our research highlights the importance of social interactions in virtual goods recommendation. The experiment’s data were retrieved from an online VW platform, and the results show that the proposed method, considering social interactions and social life circle, has better performance than existing recommendation methods.

  18. Virtual goods recommendations in virtual worlds.

    Science.gov (United States)

    Chen, Kuan-Yu; Liao, Hsiu-Yu; Chen, Jyun-Hung; Liu, Duen-Ren

    2015-01-01

    Virtual worlds (VWs) are computer-simulated environments which allow users to create their own virtual character as an avatar. With the rapidly growing user volume in VWs, platform providers launch virtual goods in haste and stampede users to increase sales revenue. However, the rapidity of development incurs virtual unrelated items which will be difficult to remarket. It not only wastes virtual global companies' intelligence resources, but also makes it difficult for users to find suitable virtual goods fit for their virtual home in daily virtual life. In the VWs, users decorate their houses, visit others' homes, create families, host parties, and so forth. Users establish their social life circles through these activities. This research proposes a novel virtual goods recommendation method based on these social interactions. The contact strength and contact influence result from interactions with social neighbors and influence users' buying intention. Our research highlights the importance of social interactions in virtual goods recommendation. The experiment's data were retrieved from an online VW platform, and the results show that the proposed method, considering social interactions and social life circle, has better performance than existing recommendation methods.

  19. Virtual PCR

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, S N; Clague, D S; Vandersall, J A; Hon, G; Williams, P L

    2006-02-23

    The polymerase chain reaction (PCR) stands among the keystone technologies for analysis of biological sequence data. PCR is used to amplify DNA, to generate many copies from as little as a single template. This is essential, for example, in processing forensic DNA samples, pathogen detection in clinical or biothreat surveillance applications, and medical genotyping for diagnosis and treatment of disease. It is used in virtually every laboratory doing molecular, cellular, genetic, ecologic, forensic, or medical research. Despite its ubiquity, we lack the precise predictive capability that would enable detailed optimization of PCR reaction dynamics. In this LDRD, we proposed to develop Virtual PCR (VPCR) software, a computational method to model the kinetic, thermodynamic, and biological processes of PCR reactions. Given a successful completion, these tools will allow us to predict both the sequences and concentrations of all species that are amplified during PCR. The ability to answer the following questions will allow us both to optimize the PCR process and interpret the PCR results: What products are amplified when sequence mixtures are present, containing multiple, closely related targets and multiplexed primers, which may hybridize with sequence mismatches? What are the effects of time, temperature, and DNA concentrations on the concentrations of products? A better understanding of these issues will improve the design and interpretation of PCR reactions. The status of the VPCR project after 1.5 years of funding is consistent with the goals of the overall project which was scoped for 3 years of funding. At half way through the projected timeline of the project we have an early beta version of the VPCR code. We have begun investigating means to improve the robustness of the code, performed preliminary experiments to test the code and begun drafting manuscripts for publication. Although an experimental protocol for testing the code was developed, the preliminary

  20. Virtual Trackballs Revisited

    DEFF Research Database (Denmark)

    Henriksen, Knud; Sporring, Jon; Hornbæk, Kasper

    2004-01-01

    Rotation of three-dimensional objects by a two-dimensional mouse is a typical task in computer-aided design, operation simulations, and desktop virtual reality. The most commonly used rotation technique is a virtual trackball surrounding the object and operated by the mouse pointer. This article...... reviews and provides a mathematical foundation for virtual trackballs. The first, but still popular, virtual trackball was described by Chen et al. [CHECK END OF SENTENCE]. We show that the virtual trackball by Chen et al. does not rotate the object along the intended great circular arc on the virtual...... trackball and we give a correction. Another popular virtual trackball is Shoemake's quaternion implementation [CHECK END OF SENTENCE], which we show to be a special case of the virtual trackball by Chen et al.. Shoemake extends the scope of the virtual trackball to the full screen. Unfortunately, Shoemake...

  1. Chat, pizarra virtual, aulas modulares virtuales

    OpenAIRE

    Demo, Juan Pablo; Painefilu, Jaime Paul; Ferreira Szpiniak, Ariel; Zorzán, Fabio

    2014-01-01

    En el presente artículo se estudian distintas herramientas sincrónicas y asincrónicas que pueden ser incorporadas dentro de un aula virtual. En particular, se analizan desde el punto de vista de integrarlas a un Entorno Virtual de Enseñanza y Aprendizaje (EVEA) específico. Los componentes seleccionados tienen que ver con comunicación por texto de forma on-line (chat), pizarras virtuales, y organización de aulas virtuales por unidades o módulos que permitan a cada alumno seguir su propia secue...

  2. Ambient Sensors

    NARCIS (Netherlands)

    Börner, Dirk; Specht, Marcus

    2014-01-01

    This software sketches comprise two custom-built ambient sensors, i.e. a noise and a movement sensor. Both sensors measure an ambient value and process the values to a color gradient (green > yellow > red). The sensors were built using the Processing 1.5.1 development environment. Available under

  3. An Affordable Virtual Reality System for Treatment of Phantom Limb Pain

    DEFF Research Database (Denmark)

    Henriksen, Bartal; Nielsen, Ronni Nedergaard; Szabo, Laszlo

    2016-01-01

    This paper describes the implementation of an affordable phantom limb pain (PLP) home treatment system using virtual reality (VR) and a motion sensor to immerse the users in a virtual environment (VE). The work is inspired by mirror therapy (MT) which is used to treat patients with PLP. This proj......This paper describes the implementation of an affordable phantom limb pain (PLP) home treatment system using virtual reality (VR) and a motion sensor to immerse the users in a virtual environment (VE). The work is inspired by mirror therapy (MT) which is used to treat patients with PLP...

  4. A Virtual Class Calculus

    DEFF Research Database (Denmark)

    Ernst, Erik; Ostermann, Klaus; Cook, William Randall

    2006-01-01

    Virtual classes are class-valued attributes of objects. Like virtual methods, virtual classes are defined in an object's class and may be redefined within subclasses. They resemble inner classes, which are also defined within a class, but virtual classes are accessed through object instances......, not as static components of a class. When used as types, virtual classes depend upon object identity - each object instance introduces a new family of virtual class types. Virtual classes support large scale program composition techniques, including higher-order hierarchies and family polymorphism. The original...... definition of virtual classes in BETA left open the question of static type safety, since some type errors were not caught until runtime. Later the languages Caesar and gbeta have used a more strict static analysis in order to ensure static type safety. However, the existence of a sound, statically typed...

  5. Organization Virtual or Networked?

    OpenAIRE

    Rūta Tamošiūnaitė

    2013-01-01

    Purpose—to present distinction between “virtual organization” and “networked organization”; giving their definitions.Design/methodology/approach—review of previous researches, systemic analyses of their findings and synthesis of distinctive characteristics of ”virtual organization” and “networked organization.”Findings—the main result of the research is key diverse features separating ”virtual organization” and ”networked organization.” Definitions of “virtual organization” and “networked org...

  6. Virtual reality exposure therapy

    OpenAIRE

    Rothbaum, BO; Hodges, L; Kooper, R

    1997-01-01

    It has been proposed that virtual reality (VR) exposure may be an alternative to standard in vivo exposure. Virtual reality integrates real-time computer graphics, body tracking devices, visual displays, and other sensory input devices to immerse a participant in a computer- generated virtual environment. Virtual reality exposure is potentially an efficient and cost-effective treatment of anxiety disorders. VR exposure therapy reduced the fear of heights in the first control...

  7. Network Virtualization Protocols

    OpenAIRE

    Fornazarič, Nejc

    2014-01-01

    Server virtualization is a widespread and well known technology that has fundamentally changed the operations in data centers. Virtual servers and data storage can be fast and easily provisioned. On the other hand network requires a lot of administrative changes and configurations that increase time of adoption. The consequences of server virtualization are changed requirements for network resources therefore the next logical step is network virtualization. The different approaches for netwo...

  8. Server virtualization solutions

    OpenAIRE

    Lodziņš, Gunārs Ernests

    2007-01-01

    Currently in the information technology sector that is responsible for a server infrastructure is a huge development in the field of server virtualization on x86 computer architecture. As a prerequisite for such a virtualization development is growth in server productivity and underutilization of available computing power. Several companies in the market are working on two virtualization architectures – hypervizor and hosting. In this paper several of virtualization products that use host...

  9. Innovative P1451-Enabled Smart Power IVHM Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA has expressed a requirement for advanced Smart Sensors to support new systems for harsh environments. Power systems are an integral component of virtually any...

  10. Virtualization A Manager's Guide

    CERN Document Server

    Kusnetzky, Dan

    2011-01-01

    What exactly is virtualization? As this concise book explains, virtualization is a smorgasbord of technologies that offer organizations many advantages, whether you're managing extremely large stores of rapidly changing data, scaling out an application, or harnessing huge amounts of computational power. With this guide, you get an overview of the five main types of virtualization technology, along with information on security, management, and modern use cases. Topics include: Access virtualization-Allows access to any application from any deviceApplication virtualization-Enables applications

  11. Metamaterial Sensors

    Directory of Open Access Journals (Sweden)

    Jing Jing Yang

    2013-01-01

    Full Text Available Metamaterials have attracted a great deal of attention due to their intriguing properties, as well as the large potential applications for designing functional devices. In this paper, we review the current status of metamaterial sensors, with an emphasis on the evanescent wave amplification and the accompanying local field enhancement characteristics. Examples of the sensors are given to illustrate the principle and the performance of the metamaterial sensor. The paper concludes with an optimistic outlook regarding the future of metamaterial sensor.

  12. Sensor networks

    NARCIS (Netherlands)

    Chatterjea, Supriyo; Thurston, J.; Kininmonth, S.; Havinga, Paul J.M.

    2006-01-01

    This article describes the details of a sensor network that is currently being deployed at the Great Barrier Reef in Australia. The sensor network allows scientists to retrieve sensor data that has a high spatial and temporal resolution. We give an overview of the energy-efficient data aggregation

  13. Attention Sensor

    NARCIS (Netherlands)

    Börner, Dirk; Kalz, Marco; Specht, Marcus

    2014-01-01

    This software sketch was used in the context of an experiment for the PhD project “Ambient Learning Displays”. The sketch comprises a custom-built attention sensor. The sensor measured (during the experiment) whether a participant looked at and thus attended a public display. The sensor was built

  14. Development of a telerobotic welding virtual environment for nuclear pipeline maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Dong, N.; Li, H.C.; Gao, H.M.; Ni, J.; Wu, L. [Harbin Inst. of Technology (China). National Key Laboratory of Advanced Welding Production Technology

    2009-03-11

    Telerobotic welding is used to maintain nuclear pipelines in hazardous and narrow environments. This paper presented a virtual environment designed to both visualize and operate a telerobotic system. The system was designed to allow operators to handle the virtual robot at local sites using a keyboard or mouse as well as to control data transfer and the robot's motor. Sensor information transfer was directed from the robot to the virtual environment via photoelectricity encoder data, visual data, force data, laser disposed data and welding data. Sensor information was presented in the virtual environment. The virtual environment design included both modelling and calibration capabilities for designing static and dynamic objects. A kinematic analysis of the 9 degrees of freedom pipeline welding robot was presented. Pipeline calibration was conducted using a surface tracking strategy with a shared force control technique. Results of the study showed that the virtual environment increased the accuracy of the telerobotic system. 5 refs., 2 tabs., 8 figs.

  15. Virtual reality for engineering

    CERN Document Server

    De Gennaro, Silvano; CERN. Geneva

    1996-01-01

    Virtual Reality for Engineers. Virtual Reality is a very powerful visualization technique for 3D data, which can bring enormous benefits to engineering design. CAD models can be exported to a VR application and used as "Virtual Prototypes". Virtual Prototypes are an ideal replacement for wooden models as they can be generated automatically from most CAD products. They are totally reliable, they can be updated in a matter of minutes, and they allow designers to explore them from inside, on a one-to-one scale and using a 3D-stereo vision. Navigation can be performed using a number of instinctive tools, such as joysticks, spaceballs, VR helmets and 3D mice. The lectures will cover today's Virtual Reality products and methods, and describe how to transform CAD models into Virtual Prototypes. A "hands on" VR experience featuring the LHC detectors models can be organized for people interested.

  16. Learning by doing virtually.

    Science.gov (United States)

    von Sternberg, N; Bartsch, M S; Petersik, A; Wiltfang, J; Sibbersen, W; Grindel, T; Tiede, U; Warnke, P H; Heiland, M; Russo, P A J; Terheyden, H; Pohlenz, P; Springer, I N

    2007-05-01

    Selective reduction of bone without collateral damage (nerves, teeth) is essential in apicectomy. To test whether skills acquired on a virtual apicectomy simulator (VOXEL-MAN system with integrated force-feedback) are transferable from virtual to physical reality, two groups of trainees were compared. Group 1 received computer-based virtual surgical training before performing an apicectomy in a pig cadaver model. The probability of preserving vital neighboring structures was improved significantly, i.e. six-fold, after virtual surgical training (P<0.001). The average volume of the bony defects created by the trainees of Group 2 (mean: 0.47 ml) was significantly (P<0.001) larger than by the trainees of Group 1 (mean: 0.25 ml). Most importantly, the ability to objectively self-assess performance was significantly improved after virtual training. Training with a virtual apicectomy simulator appears to be effective, and the skills acquired are transferable to physical reality.

  17. Virtual Campus Hub technology

    DEFF Research Database (Denmark)

    Vercoulen, Frank; Badger, Merete; Monaco, Lucio

    This deliverable briefly describes which technological components have been delivered for the Virtual Campus Hub and how they can be used. A detailed discussion of the technical details of the components, how they were realized and how they fit the VCH concept can be found in deliverables D5.......4. Virtual Campus Hub Technology Evaluation Report and D6.7 The Virtual Campus Hub Concept....

  18. A Virtual Reality System for Treatment of Phantom Limb Pain using Game Training and Motion Tracking

    DEFF Research Database (Denmark)

    Henriksen, Bartal; Nielsen, Ronni Nedergaard; Szabo, Laszlo

    2016-01-01

    This paper describes the implementation of a phantom limb pain (PLP) home-based system using virtual reality (VR) and a motion sensor to immerse the users in a virtual environment (VE). The work is inspired by mirror therapy (MT), which has been used to relieve PLP. The target patient group focuses...

  19. Virtual Environments for Training

    National Research Council Canada - National Science Library

    Stiles, R

    1998-01-01

    .... Progress on productization of the VET Training Studio software includes increased robustness for Vista virtual environment display and interaction services, a new capability to use the STEVE visual...

  20. Spacebody actual virtual

    DEFF Research Database (Denmark)

    Kjøbek, Jytte; Sørensen, Gert

    2005-01-01

    DVD som indeholder filmen 'spacebody actual virtual' . Videoen er værkdelen af forskningsprojektet Arkitektur og skikkelse, spacebody actual virtual. Foruden DVD'en indeholder projektet et reflekterende materiale på hjemmesiden www.spacebody.dk Fysisk medie: DVD......DVD som indeholder filmen 'spacebody actual virtual' . Videoen er værkdelen af forskningsprojektet Arkitektur og skikkelse, spacebody actual virtual. Foruden DVD'en indeholder projektet et reflekterende materiale på hjemmesiden www.spacebody.dk Fysisk medie: DVD...

  1. Virtual Training Devices Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Virtual Training Devices (VTD) Laboratory at the Life Cycle Software Engineering Center, Picatinny Arsenal, provides a software testing and support environment...

  2. Virtual Reality Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Performs basic and applied research in interactive 3D computer graphics, including visual analytics, virtual environments, and augmented reality (AR). The...

  3. Smart sensors

    Science.gov (United States)

    Corsi, Carlo

    2006-08-01

    The term "Smart Sensors" refer to sensors which contain both sensing and signal processing capabilities with objectives ranging from simple viewing to sophisticated remote sensing, surveillance, search/track, weapon guidance, robotics, perceptronics and intelligence applications. In a broad sense, they include any sensor systems covering the whole electromagnetic spectrum: this paper deals specifically with a new class of smart sensors in infrared spectral bands whose developments started some years ago, when it was recognized that the rapid advances of "very large scale integration" (VLSI) processor technology and mosaic infrared detector array technology could be combined to develop new generations of infrared smart sensor systems with much improved performance. So, sophisticated signal processing operations have been developed for these new systems by integrating microcomputers and other VLSI signal processors within or next to the sensor arrays on the same focal plane avoiding complex computing located far away from the sensors. Recently this approach is achieving higher goals by a new and revolutionary sensors concept which introduce inside the sensor some of the basic function of living eyes, such as dynamic stare, dishomogenity compensation, spatial and temporal filtering. New objectives and requirements of these new focal plane processors are presented for this type of new infrared smart sensor systems. This paper is concerned with the processing techniques for only the front end of the focal plane processing, namely, the enhancement of target-to-noise ratio by background clutter suppression and the improvement in target detection by "smart" and pattern correlation threshold.

  4. OVERLAPPING VIRTUAL CADASTRAL DOCUMENTATION

    Directory of Open Access Journals (Sweden)

    Madalina - Cristina Marian

    2013-12-01

    Full Text Available Two cadastrale plans of buildings, can overlap virtual. Overlap is highlighted when digital reception. According to Law no. 7/1996 as amended and supplemented, to solve these problems is by updating the database graphs, the repositioning. This paper addresses the issue of overlapping virtual cadastre in the history of the period 1999-2012.

  5. Virtual School Counseling

    Science.gov (United States)

    Osborn, Debra S.; Peterson, Gary W.; Hale, Rebecca R.

    2015-01-01

    The advent of virtual schools opens doors to opportunity for delivery of student services via the Internet. Through the use of structured interviews with four practicing Florida virtual school counselors, and a follow-up survey, the authors examined the experiences and reflections of school counselors who are employed full time in a statewide…

  6. Virtual Pediatric Hospital

    Science.gov (United States)

    ... Thoracopaedia - An Imaging Encyclopedia of Pediatric Thoracic Disease Virtual Pediatric Hospital is the Apprentice's Assistant™ Last revised ... pediatric resources: GeneralPediatrics.com | PediatricEducation.org | SearchingPediatrics.com Virtual Pediatric Hospital is curated by Donna M. D' ...

  7. Virtual Seminar Room

    DEFF Research Database (Denmark)

    Forchhammer, Søren Otto; Fosgerau, Anders; Hansen, Peter Søren Kirk

    1999-01-01

    The initial design considerations and research goals for an ATM network based virtual seminar room with 5 sites are presented.......The initial design considerations and research goals for an ATM network based virtual seminar room with 5 sites are presented....

  8. Virtual Company and Modelbank

    DEFF Research Database (Denmark)

    Thorsteinsson, Uffe

    1996-01-01

    Ansøgning til Socrates programmet vedr. Tematisk netværk inden for området Virtual Company and Modelbank......Ansøgning til Socrates programmet vedr. Tematisk netværk inden for området Virtual Company and Modelbank...

  9. Virtual Trauma Team

    NARCIS (Netherlands)

    Jones, Valerie M.; Bults, Richard G.A.

    2001-01-01

    The clinical motivation for Virtual Trauma Team is to improve quality of care in trauma care in the vital first "golden hour" where correct intervention can greatly improve likely health outcome. The motivation for Virtual Homecare Team is to improve quality of life and independence for patients by

  10. Virtual Reality in Psychology

    Science.gov (United States)

    Foreman, Nigel

    2009-01-01

    The benefits of using virtual environments (VEs) in psychology arise from the fact that movements in virtual space, and accompanying perceptual changes, are treated by the brain in much the same way as those in equivalent real space. The research benefits of using VEs, in areas of psychology such as spatial learning and cognition, include…

  11. A Virtual Good Idea

    Science.gov (United States)

    Bolch, Matt

    2009-01-01

    School districts across the country have always had to do more with less. Funding goes only so far, leaving administrators and IT staff to find innovative ways to save money while maintaining a high level of academic quality. Creating virtual servers accomplishes both tasks, district technology personnel say. Virtual environments not only allow…

  12. 10 Myths of Virtualization

    Science.gov (United States)

    Schaffhauser, Dian

    2012-01-01

    Half of servers in higher ed are virtualized. But that number's not high enough for Link Alander, interim vice chancellor and CIO at the Lone Star College System (Texas). He aspires to see 100 percent of the system's infrastructure requirements delivered as IT services from its own virtualized data centers or other cloud-based operators. Back in…

  13. Taxation of virtual currency

    NARCIS (Netherlands)

    Bal, Aleksandra Marta

    2014-01-01

    The Information Age has created a new concept of money – virtual currencies existing solely in the cyberspace in the form of intangible computer code. The most prominent virtual currency scheme, Bitcoin, grabbed the public attention as its value skyrocketed at the beginning of 2012. Whereas Bitcoin

  14. Virtual reality musical instruments

    DEFF Research Database (Denmark)

    Serafin, Stefania; Erkut, Cumhur; Kojs, Juraj

    2016-01-01

    The rapid development and availability of low cost technologies has created a wide interest in virtual reality (VR), but how to design and evaluate multisensory interactions in VR remains as a challenge. In this paper, we focus on virtual reality musical instruments, present an overview of our...

  15. Designing Virtual Learning Environments

    DEFF Research Database (Denmark)

    Veirum, Niels Einar

    2003-01-01

    The main objective of this working paper is to present a conceptual model for media integrated communication in virtual learning environments. The model for media integrated communication is very simple and identifies the necessary building blocks for virtual place making in a synthesis of methods...

  16. The issue of virtual teams

    OpenAIRE

    Fleiberková, Šárka

    2012-01-01

    The aim of this diploma thesis is the introduction of teamwork and virtual teams. The theoretical part of this work describes the birth of teamwork, its definition, properties, advantages and disadvantages. Next part of diploma thesis is dedicated to the virtual team. It describes the difference among virtual and traditional team, definition and characteristics of virtual team as well as tools that are used in virtual team. The second, practical, unit is focused on virtual teams at universiti...

  17. Ubiquitous Virtual Private Network: A Solution for WSN Seamless Integration

    Directory of Open Access Journals (Sweden)

    David Villa

    2014-01-01

    Full Text Available Sensor networks are becoming an essential part of ubiquitous systems and applications. However, there are no well-defined protocols or mechanisms to access the sensor network from the enterprise information system. We consider this issue as a heterogeneous network interconnection problem, and as a result, the same concepts may be applied. Specifically, we propose the use of object-oriented middlewares to provide a virtual private network in which all involved elements (sensor nodes or computer applications will be able to communicate as if all of them were in a single and uniform network.

  18. VEM: Virtual Enterprise Methodology

    DEFF Research Database (Denmark)

    Tølle, Martin; Vesterager, Johan

    2003-01-01

    This chapter presents a virtual enterprise methodology (VEM) that outlines activities to consider when setting up and managing virtual enterprises (VEs). As a methodology the VEM helps companies to ask the right questions when preparing for and setting up an enterprise network, which works as a b...... as a breeding ground for setting up VEs. The VEM applies the Virtual Enterprise Reference Architecture (VERA) as an underlying structure. Both VEM and VERA are developed as a part of the GLOBEMEN project.......This chapter presents a virtual enterprise methodology (VEM) that outlines activities to consider when setting up and managing virtual enterprises (VEs). As a methodology the VEM helps companies to ask the right questions when preparing for and setting up an enterprise network, which works...

  19. Interactive Virtual Cinematography

    DEFF Research Database (Denmark)

    Burelli, Paolo

    control of the camera by the player increases the complexity of the interaction and reduces the designer's control on game storytelling. A completely designer-driven camera releases the player from the burden of controlling the point of view, but might generate undesired camera behaviours. Furthermore......A virtual camera represents the point-of-view of the player through which she perceives the game world and gets feedback on her actions. Thus, the virtual camera plays a vital role in 3D computer games and aects player experience and enjoyability in games. Interactive virtual cinematography...... is the process of visualising the content of a virtual environment by positioning and animating the virtual camera in the context of interactive applications such as a computer game. Camera placement and animation in games are usually directly controlled by the player or statically predened by designers. Direct...

  20. Virtual Project Teams

    DEFF Research Database (Denmark)

    Bjørn, Pernille

    in virtual project teams whose members are spread across various geographical locations. The aim is to understand the specific factors, conditions and challenges underpinning such situations. This thesis describes, analyses and discusses three in-depth empirical studies on the practices and use of groupware...... technology in six real-life virtual teams, two in industry and four in education, applying interpretative research and action research methods. Two main lines of investigation are pursued: the first involves an examination of the organisational issues related to groupware adaptation in virtual project teams......, while the second looks at the social context and practices of virtual project teams. Two of the key findings are 1) that the process of groupware adaptation by virtual project teams can be viewed as a process of expanding and aligning the technological frames of the participants, which includes mutual...

  1. Gas Sensor

    KAUST Repository

    Luebke, Ryan

    2015-01-22

    A gas sensor using a metal organic framework material can be fully integrated with related circuitry on a single substrate. In an on-chip application, the gas sensor can result in an area-efficient fully integrated gas sensor solution. In one aspect, a gas sensor can include a first gas sensing region including a first pair of electrodes, and a first gas sensitive material proximate to the first pair of electrodes, wherein the first gas sensitive material includes a first metal organic framework material.

  2. Virtual microscopy in virtual tumor banking

    NARCIS (Netherlands)

    Isabelle, M.; Teodorovic, I.; Oosterhuis, J. W.; Riegman, P. H. J.; Passioukov, A.; Lejeune, S.; Therasse, P.; Dinjens, W. N. M.; Lam, K. H.; Oomen, M. H. A.; Spatz, A.; Ratcliffe, C.; Knox, K.; Mager, R.; Kerr, D.; Pezzella, F.; van Damme, B.; van de Vijver, M.; van Boven, H.; Morente, M. M.; Alonso, S.; Kerjaschki, D.; Pammer, J.; López-Guerrero, J. A.; Llombart-Bosch, A.; Carbone, A.; Gloghini, A.; van Veen, E. B.

    2006-01-01

    Many systems have already been designed and successfully used for sharing histology images over large distances, without transfer of the original glass slides. Rapid evolution was seen when digital images could be transferred over the Internet. Nowadays, sophisticated virtual microscope systems can

  3. Molecular Rift: Virtual Reality for Drug Designers.

    Science.gov (United States)

    Norrby, Magnus; Grebner, Christoph; Eriksson, Joakim; Boström, Jonas

    2015-11-23

    Recent advances in interaction design have created new ways to use computers. One example is the ability to create enhanced 3D environments that simulate physical presence in the real world--a virtual reality. This is relevant to drug discovery since molecular models are frequently used to obtain deeper understandings of, say, ligand-protein complexes. We have developed a tool (Molecular Rift), which creates a virtual reality environment steered with hand movements. Oculus Rift, a head-mounted display, is used to create the virtual settings. The program is controlled by gesture-recognition, using the gaming sensor MS Kinect v2, eliminating the need for standard input devices. The Open Babel toolkit was integrated to provide access to powerful cheminformatics functions. Molecular Rift was developed with a focus on usability, including iterative test-group evaluations. We conclude with reflections on virtual reality's future capabilities in chemistry and education. Molecular Rift is open source and can be downloaded from GitHub.

  4. Design of virtual three-dimensional instruments for sound control

    Science.gov (United States)

    Mulder, Axel Gezienus Elith

    An environment for designing virtual instruments with 3D geometry has been prototyped and applied to real-time sound control and design. It enables a sound artist, musical performer or composer to design an instrument according to preferred or required gestural and musical constraints instead of constraints based only on physical laws as they apply to an instrument with a particular geometry. Sounds can be created, edited or performed in real-time by changing parameters like position, orientation and shape of a virtual 3D input device. The virtual instrument can only be perceived through a visualization and acoustic representation, or sonification, of the control surface. No haptic representation is available. This environment was implemented using CyberGloves, Polhemus sensors, an SGI Onyx and by extending a real- time, visual programming language called Max/FTS, which was originally designed for sound synthesis. The extension involves software objects that interface the sensors and software objects that compute human movement and virtual object features. Two pilot studies have been performed, involving virtual input devices with the behaviours of a rubber balloon and a rubber sheet for the control of sound spatialization and timbre parameters. Both manipulation and sonification methods affect the naturalness of the interaction. Informal evaluation showed that a sonification inspired by the physical world appears natural and effective. More research is required for a natural sonification of virtual input device features such as shape, taking into account possible co- articulation of these features. While both hands can be used for manipulation, left-hand-only interaction with a virtual instrument may be a useful replacement for and extension of the standard keyboard modulation wheel. More research is needed to identify and apply manipulation pragmatics and movement features, and to investigate how they are co-articulated, in the mapping of virtual object

  5. Aptamer Sensors

    OpenAIRE

    Marrazza, Giovanna

    2017-01-01

    In the last years, great progress has been accomplished in the development of aptamer sensors with different transducers. In order to improve the sensitivity of these biosensors, several methodologies have been employed. In this Special Issue, the state of art and the future trends in the field of aptamer sensors have been explored.

  6. Virtualization Security Combining Mandatory Access Control and Virtual Machine Introspection

    OpenAIRE

    Win, Thu Yein; Tianfield, Huaglory; Mair, Quentin

    2014-01-01

    Virtualization has become a target for attacks in cloud computing environments. Existing approaches to protecting the virtualization environment against the attacks are limited in protection scope and are with high overheads. This paper proposes a novel virtualization security solution which aims to provide comprehensive protection of the virtualization environment.

  7. REVIEW ARTICLE: The transmission interferometric adsorption sensor

    Science.gov (United States)

    Heuberger, M.; Balmer, T. E.

    2007-12-01

    This paper describes a high-speed adsorption sensor based on thin-film interference at the interfaces. The sensor can be used as a stand-alone instrument or in combination with a direct surface force measurement, which yields a wide range of additional information on molecular interactions on adsorbed films. The achieved mass resolution of the presented method (1-10 ng cm-2 Hz-1/2) is comparable to or better than other modern bio-sensors. The dependence of mass resolution on various factors is presented and demonstrated in a number of relevant examples. The described method is suitable for the implementation of a low-cost bio-sensor with a minimal number of optical elements. The measurement spot size is one micrometre or more and sampling rates >10 Hz are readily possible. In contrast to other bio-sensors, the signal baseline has a remarkable long-term stability since the measured signal is virtually independent of refractive index changes in the fluid medium above the sensor surface. In combination with an optical spectral correlation method, the classical computer calculations are substituted by an optical calculator and a label-free real-time imaging adsorption sensor is realized. We demonstrate sensor operation both inside the extended surface forces apparatus as well as in a stand-alone bio-sensor configuration. As a final point, we illustrate the imaging capability of this new sensor technology on a patterned bio-functionalized surface.

  8. Soldier sensor

    Science.gov (United States)

    Kossives, Dean P.

    2010-04-01

    A new sensor system, whose functionality is not reliant on mass spectrometric or ionization methods, is combined with a substrate technology which allows for separately optimized control circuits and standardized advanced sensors in a simple packaging methodology to foster an entirely new generation of modular optical sensors. These sensors will be based on biologic and chromic compounds. The compounds will utilize reversible reaction chemistry to enable self cleaning. The detector's operation is based on simple changes in absorbance, reflectance, color, or other optical properties. The time to saturation of the sensor will determine the relative concentration in the air. A detection scheme based on these properties will function in high background levels and also be able to pick up low level concentrations as well.

  9. Pathogen Sensors

    Directory of Open Access Journals (Sweden)

    Joseph Irudayaraj

    2009-10-01

    Full Text Available The development of sensors for detecting foodborne pathogens has been motivated by the need to produce safe foods and to provide better healthcare. However, in the more recent times, these needs have been expanded to encompass issues relating to biosecurity, detection of plant and soil pathogens, microbial communities, and the environment. The range of technologies that currently flood the sensor market encompass PCR and microarray-based methods, an assortment of optical sensors (including bioluminescence and fluorescence, in addition to biosensor-based approaches that include piezoelectric, potentiometric, amperometric, and conductometric sensors to name a few. More recently, nanosensors have come into limelight, as a more sensitive and portable alternative, with some commercial success. However, key issues affecting the sensor community is the lack of standardization of the testing protocols and portability, among other desirable elements, which include timeliness, cost-effectiveness, user-friendliness, sensitivity and specificity. [...

  10. Virtual environment application with partial gravity simulation

    Science.gov (United States)

    Ray, David M.; Vanchau, Michael N.

    1994-01-01

    To support manned missions to the surface of Mars and missions requiring manipulation of payloads and locomotion in space, a training facility is required to simulate the conditions of both partial and microgravity. A partial gravity simulator (Pogo) which uses pneumatic suspension is being studied for use in virtual reality training. Pogo maintains a constant partial gravity simulation with a variation of simulated body force between 2.2 and 10 percent, depending on the type of locomotion inputs. this paper is based on the concept and application of a virtual environment system with Pogo including a head-mounted display and glove. The reality engine consists of a high end SGI workstation and PC's which drive Pogo's sensors and data acquisition hardware used for tracking and control. The tracking system is a hybrid of magnetic and optical trackers integrated for this application.

  11. The Virtual Dressing Room

    DEFF Research Database (Denmark)

    Holte, Michael Boelstoft; Gao, Yi; Petersson, Eva

    2015-01-01

    This paper presents the design and evaluation of a usability and user experience test of a virtual dressing room. First, we motivate and introduce our recent developed prototype of a virtual dressing room. Next, we present the research and test design grounded in related usability and user...... experience studies. We give a description of the experimental setup and the execution of the designed usability and user experience test. To this end, we report interesting results and discuss the results with respect to user-centered design and development of a virtual dressing room....

  12. Virtual neutron scattering experiments

    DEFF Research Database (Denmark)

    Overgaard, Julie Hougaard; Bruun, Jesper; May, Michael

    2016-01-01

    We describe how virtual experiments can be utilized in a learning design that prepares students for hands-on experiments at large-scale facilities. We illustrate the design by showing how virtual experiments are used at the Niels Bohr Institute in a master level course on neutron scattering....... In the last week of the course, students travel to a large-scale neutron scattering facility to perform real neutron scattering experiments. Through student interviews and survey answers, we argue, that the virtual training prepares the students to engage more fruitfully with experiments by letting them focus...

  13. Design, Development and Calibration of Virtual System for Relative Humidity Measurement

    Directory of Open Access Journals (Sweden)

    Georgi NIKOLOV

    2008-06-01

    Full Text Available In the present paper a frequency mode data acquisition technique, which converts directly relative humidity into a frequency signal, is considered. The system is realized using low cost oscillator, multifunction data acquisition board and capability of virtual instrumentation. In order to automate calibration procedures appropriate software (so called virtual instrument is developed and described in brief. Using possibility of virtual instrumentation or to be more precise the build in LabVIEW probability, statistics and interpolation functions a method to increase calibration accuracy is suggested and put into practice. Following this approach the polynomial calibration equation for capacitive sensor is extracted and saved in transducer electronic data sheets file. As example of proposed approach a virtual system based on relative humidity capacitive sensor is realized. The main objective of this paper is to demonstrate how with virtual instrumentation can be solved some difficult engineering problems such as relative humidity calibration and measurement.

  14. Wearable Sensor Networks for Motion Capture

    Directory of Open Access Journals (Sweden)

    Dennis Arsenault

    2015-08-01

    Full Text Available This work presents the development of a full body sensor-based motion tracking system that functions through wearable inertial sensors. The system is comprised of a total of ten wearable sensors and maps the player's motions to an on-screen character in real-time. A hierarchical skeletal model was implemented that allows players to navigate and interact with the virtual world without the need of a hand-held controller. To demonstrate the capabilities of the system, a simple virtual reality game was created. As a wearable system, the ability for the users to engage in activities while not being tied to a camera system, or being forced indoors presents a significant opportunity for mobile entertainment, augmented reality and interactive systems that use the body as a significant form of input. This paper outlines the key developments necessary to implement such a system.

  15. Virtual neutron scattering experiments

    DEFF Research Database (Denmark)

    Overgaard, Julie Hougaard; Bruun, Jesper; May, Michael

    2017-01-01

    . In the last week of the course, students travel to a large-scale neutron scattering facility to perform real neutron scattering experiments. Through student interviews and survey answers, we argue, that the virtual training prepares the students to engage more fruitfully with experiments by letting them focus......We describe how virtual experiments can be utilized in a learning design that prepares students for hands-on experiments at large-scale facilities. We illustrate the design by showing how virtual experiments are used at the Niels Bohr Institute in a master level course on neutron scattering...... on physics and data rather than the overwhelming instrumentation. We argue that this is because they can transfer their virtual experimental experience to the real-life situation. However, we also find that learning is still situated in the sense that only knowledge of particular experiments is transferred...

  16. Virtual Factory Testbed

    Data.gov (United States)

    Federal Laboratory Consortium — The Virtual Factory Testbed (VFT) is comprised of three physical facilities linked by a standalone network (VFNet). The three facilities are the Smart and Wireless...

  17. Virtual neutron scattering experiments

    DEFF Research Database (Denmark)

    Overgaard, Julie Hougaard; Bruun, Jesper; May, Michael

    2016-01-01

    We describe how virtual experiments can be utilized in a learning design that prepares students for hands-on experiments at large-scale facilities. We illustrate the design by showing how virtual experiments are used at the Niels Bohr Institute in a master level course on neutron scattering....... In the last week of the course, students travel to a large-scale neutron scattering facility to perform real neutron scattering experiments. Through student interviews and survey answers, we argue, that the virtual training prepares the students to engage more fruitfully with experiments by letting them focus...... on physics and data rather than the overwhelming instrumentation. We argue that this is because they can transfer their virtual experimental experience to the real-life situation. However, we also find that learning is still situated in the sense that only knowledge of particular experiments is transferred...

  18. Virtual Organizations: An Overview

    Science.gov (United States)

    Nami, Mohammad Reza

    The need to remain competitive in the open market forces companies to concentrate on their core competencies while searching for alliances when additional skills or resources are needed to fulfill business opportunities. The changing business situation of companies and customer needs have motivated researchers to introduce Virtual Organization (VO) idea. A Virtual Organization is always a form of partnership and managing partners and handling partnerships are crucial. Virtual organizations are defined as a temporary collection of enterprises that cooperate and share resources, knowledge, and competencies to better respond to business opportunities. This paper presents base concepts of virtual organizations including properties, management concepts, operational concepts, and main issues in collaboration such as security and authentication.

  19. Cuenca, realidad virtual

    National Research Council Canada - National Science Library

    Concepción Rodríguez Ruza; Adela Mª Muñoz Marquina; Aurelio Lorente González; Virginia Cañas Córdoba

    2012-01-01

    This project, Cuenca, realidad virtual, was created so that the key periods of the historical evolution of Cuenca could be explained, where the Islamic Cuenca, Christian Cuenca and Cuenca in the 18th...

  20. Virtual realities and education

    OpenAIRE

    Curcio Igor D.D.; Dipace Anna; Norlund Anita

    2016-01-01

    The purpose of this article is to highlight the state of the art of virtual reality, augmented reality, mixed reality technologies and their applications in formal education. We also present a selected list of case studies that prove the utility of these technologies in the context of formal education. Furthermore, as byproduct, the mentioned case studies show also that, although the industry is able to develop very advanced virtual environment technologies, their pedagogical implications are...

  1. Transforming Virtual Teams

    DEFF Research Database (Denmark)

    Bjørn, Pernille

    2005-01-01

    Investigating virtual team collaboration in industry using grounded theory this paper presents the in-dept analysis of empirical work conducted in a global organization of 100.000 employees where a global virtual team with participants from Sweden, United Kingdom, Canada, and North America were...... multiple communities, and bringing visibility to articulation work, and that groupware technology should facilitate communication and negotiation instead of implementing the workflows just enhancing existing abilities, practices, and skills....

  2. Piezoceramic Sensors

    CERN Document Server

    Sharapov, Valeriy

    2011-01-01

    This book presents the latest and complete information about various types of piezosensors. A sensor is a converter of the measured physical size to an electric signal. Piezoelectric transducers and sensors are based on piezoelectric effects. They have proven to be versatile tools for the measurement of various processes. They are used for quality assurance, process control and for research and development in many different industries. In each area of application specific requirements to the parameters of transducers and sensors are developed. This book presents the fundamentals, technical des

  3. Virtualization Technologies for the Business

    OpenAIRE

    Sabina POPESCU

    2011-01-01

    There is a new trend of change in today's IT industry. It's called virtualization. In datacenter virtualization can occur on several levels, but the type of virtualization has created this trend change is the operating system offered or server virtualization. OS virtualization technologies come in two forms. First, there is a software component that is used to simulate a natural machine that has total control of an operating system operating on the host equipment. The second is a hypervisor, ...

  4. Virtual hand illusion induced by visuomotor correlations.

    Science.gov (United States)

    Sanchez-Vives, Maria V; Spanlang, Bernhard; Frisoli, Antonio; Bergamasco, Massimo; Slater, Mel

    2010-04-29

    Our body schema gives the subjective impression of being highly stable. However, a number of easily-evoked illusions illustrate its remarkable malleability. In the rubber-hand illusion, illusory ownership of a rubber-hand is evoked by synchronous visual and tactile stimulation on a visible rubber arm and on the hidden real arm. Ownership is concurrent with a proprioceptive illusion of displacement of the arm position towards the fake arm. We have previously shown that this illusion of ownership plus the proprioceptive displacement also occurs towards a virtual 3D projection of an arm when the appropriate synchronous visuotactile stimulation is provided. Our objective here was to explore whether these illusions (ownership and proprioceptive displacement) can be induced by only synchronous visuomotor stimulation, in the absence of tactile stimulation. To achieve this we used a data-glove that uses sensors transmitting the positions of fingers to a virtually projected hand in the synchronous but not in the asynchronous condition. The illusion of ownership was measured by means of questionnaires. Questions related to ownership gave significantly larger values for the synchronous than for the asynchronous condition. Proprioceptive displacement provided an objective measure of the illusion and had a median value of 3.5 cm difference between the synchronous and asynchronous conditions. In addition, the correlation between the feeling of ownership of the virtual arm and the size of the drift was significant. We conclude that synchrony between visual and proprioceptive information along with motor activity is able to induce an illusion of ownership over a virtual arm. This has implications regarding the brain mechanisms underlying body ownership as well as the use of virtual bodies in therapies and rehabilitation.

  5. Virtual hand illusion induced by visuomotor correlations.

    Directory of Open Access Journals (Sweden)

    Maria V Sanchez-Vives

    Full Text Available BACKGROUND: Our body schema gives the subjective impression of being highly stable. However, a number of easily-evoked illusions illustrate its remarkable malleability. In the rubber-hand illusion, illusory ownership of a rubber-hand is evoked by synchronous visual and tactile stimulation on a visible rubber arm and on the hidden real arm. Ownership is concurrent with a proprioceptive illusion of displacement of the arm position towards the fake arm. We have previously shown that this illusion of ownership plus the proprioceptive displacement also occurs towards a virtual 3D projection of an arm when the appropriate synchronous visuotactile stimulation is provided. Our objective here was to explore whether these illusions (ownership and proprioceptive displacement can be induced by only synchronous visuomotor stimulation, in the absence of tactile stimulation. METHODOLOGY/PRINCIPAL FINDINGS: To achieve this we used a data-glove that uses sensors transmitting the positions of fingers to a virtually projected hand in the synchronous but not in the asynchronous condition. The illusion of ownership was measured by means of questionnaires. Questions related to ownership gave significantly larger values for the synchronous than for the asynchronous condition. Proprioceptive displacement provided an objective measure of the illusion and had a median value of 3.5 cm difference between the synchronous and asynchronous conditions. In addition, the correlation between the feeling of ownership of the virtual arm and the size of the drift was significant. CONCLUSIONS/SIGNIFICANCE: We conclude that synchrony between visual and proprioceptive information along with motor activity is able to induce an illusion of ownership over a virtual arm. This has implications regarding the brain mechanisms underlying body ownership as well as the use of virtual bodies in therapies and rehabilitation.

  6. Vibrissa Sensor

    Science.gov (United States)

    2016-09-30

    Docket No. 300119 1 of 11 VIBRISSA SENSOR STATEMENT OF GOVERNMENT INTEREST [0001] The invention described herein may be manufactured and used by...REFERENCE TO OTHER PATENT APPLICATIONS [0002] None. BACKGROUND OF THE INVENTION (1) Field of the Invention [0003] The present invention provides a...vibrissa in two dimensions. SUMMARY OF THE INVENTION [0010] Accordingly, it is an object of the present invention to provide a sensor capable of

  7. Availability Model for Virtualized Platforms

    Directory of Open Access Journals (Sweden)

    Jiri Hlavacek

    2013-01-01

    Full Text Available Network virtualization is a method of providing virtual instances of physical networks. Virtualized networks are widely used with virtualized servers, forming a powerful dynamically reconfigurable platform. In this paper we discuss the impact of network virtualization on the overall system availability. We describe a system reflecting the network architecture usually deployed in today’s data centres. The proposed system is modelled using Markov chains and fault trees. We compare the availability of virtualized system using standard physique network with the availability of virtualized system using virtualized network. Network virtualization introduces a new software layer to the network architecture. The proposed availability model integrates software failures in addition to the hardware failures. Based on the estimated numerical failure rates, we analyse system’s availability.

  8. The virtual slice setup.

    Science.gov (United States)

    Lytton, William W; Neymotin, Samuel A; Hines, Michael L

    2008-06-30

    In an effort to design a simulation environment that is more similar to that of neurophysiology, we introduce a virtual slice setup in the NEURON simulator. The virtual slice setup runs continuously and permits parameter changes, including changes to synaptic weights and time course and to intrinsic cell properties. The virtual slice setup permits shocks to be applied at chosen locations and activity to be sampled intra- or extracellularly from chosen locations. By default, a summed population display is shown during a run to indicate the level of activity and no states are saved. Simulations can run for hours of model time, therefore it is not practical to save all of the state variables. These, in any case, are primarily of interest at discrete times when experiments are being run: the simulation can be stopped momentarily at such times to save activity patterns. The virtual slice setup maintains an automated notebook showing shocks and parameter changes as well as user comments. We demonstrate how interaction with a continuously running simulation encourages experimental prototyping and can suggest additional dynamical features such as ligand wash-in and wash-out-alternatives to typical instantaneous parameter change. The virtual slice setup currently uses event-driven cells and runs at approximately 2 min/h on a laptop.

  9. Varieties of virtualization

    Science.gov (United States)

    Ellis, Stephen R.

    1991-01-01

    Natural environments have a content, i.e., the objects in them; a geometry, i.e., a pattern of rules for positioning and displacing the objects; and a dynamics, i.e., a system of rules describing the effects of forces acting on the objects. Human interaction with most common natural environments has been optimized by centuries of evolution. Virtual environments created through the human-computer interface similarly have a content, geometry, and dynamics, but the arbitrary character of the computer simulation creating them does not insure that human interaction with these virtual environments will be natural. The interaction, indeed, could be supernatural but it also could be impossible. An important determinant of the comprehensibility of a virtual environment is the correspondence between the environmental frames of reference and those associated with the control of environmental objects. The effects of rotation and displacement of control frames of reference with respect to corresponding environmental references differ depending upon whether perceptual judgement or manual tracking performance is measured. The perceptual effects of frame of reference displacement may be analyzed in terms of distortions in the process of virtualizing the synthetic environment space. The effects of frame of reference displacement and rotation have been studied by asking subjects to estimate exocentric direction in a virtual space.

  10. First Indico Virtual Event

    CERN Multimedia

    CERN. Geneva

    2014-01-01

    The first Indico virtual event will take place on February 4th 15:00 and will focus on two main topics The release of Indico v1.2 The migration of the OO Indico backend database (ZODB) to a more standard DBMS It will be fully virtual using the CERN Vidyo service and will foster discussions between developers and administrators of Indico servers worldwide. Connections to the virtual room will be open, but attendees are encouraged to register to the event, in order to be informed of any changes in the organisation if any. If you would like to add a topic of discussion or propose yourself a contribution, please let us know at indico-team@cern.ch. Connection to Vidyo Vidyo connection details are available here CERN Vidyo service documentation can be found here First-time users are encouraged to try the service before connecting to the real event

  11. Virtual Reality Musical Instruments

    DEFF Research Database (Denmark)

    Serafin, Stefania; Erkut, Cumhur; Kojs, Juraj

    2016-01-01

    The rapid development and availability of low-cost technologies have created a wide interest in virtual reality. In the field of computer music, the term “virtual musical instruments” has been used for a long time to describe software simulations, extensions of existing musical instruments......, and ways to control them with new interfaces for musical expression. Virtual reality musical instruments (VRMIs) that include a simulated visual component delivered via a head-mounted display or other forms of immersive visualization have not yet received much attention. In this article, we present a field...... overview of VRMIs from the viewpoint of the performer. We propose nine design guidelines, describe evaluation methods, analyze case studies, and consider future challenges....

  12. Material and Virtuality

    DEFF Research Database (Denmark)

    Kruse Aagaard, Anders

    2015-01-01

    Through tangible experiments this paper discusses the dialogues between digital architectural drawing and the process of materialisation. The paper sets op the spans between virtual and actual and control and uncertainty making these oppositions a combined spaces where information between a digital...... world and a physical world can interchange. The paper suggest an approach where an overlapping of virtuality and the tangible material output from digital fabrication machines create a method of using materialisation tools as instruments to connect the reality of materials and to an exploring process...... through these experiments is both tangible and directly connected to real actions in digital drawing or material processing but also the base for theoretical contemplations of the relation between virtual and actual and control and uncertainty....

  13. Virtual-World Naturalism

    Directory of Open Access Journals (Sweden)

    Daniel Reynolds

    2010-07-01

    Full Text Available Sometimes a player will stray from the path described by a game, moving into new spaces, developing new possible modes of interaction, and often discovering the rougher edges of the game world, where physics models break down, textures become incongruous, and the pieces don’t quite fit together. Gameplay that seeks out these spaces and these phenomena, that searches for such clues to the underlying construction of the virtual environment, is a kind of virtual-world naturalism, at once a return to an investigative urge that has been subsumed to the exhaustive mapping and description of the real world and a form of resistance to the very idea of pre-defined paths of action, of externally imposed limits, in virtual worlds as well as in our own.

  14. Mapping, Awareness, And Virtualization Network Administrator Training Tool Virtualization Module

    Science.gov (United States)

    2016-03-01

    AND VIRTUALIZATION NETWORK ADMINISTRATOR TRAINING TOOL VIRTUALIZATION MODULE by Erik W. Berndt March 2016 Thesis Advisor: John Gibson...REPORT TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE MAPPING, AWARENESS, AND VIRTUALIZATION NETWORK ADMINISTRATOR TRAINING TOOL... VIRTUALIZATION MODULE 5. FUNDING NUMBERS 6. AUTHOR(S) Erik W. Berndt 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Naval Postgraduate School

  15. Oftalmologia e realidade virtual

    Directory of Open Access Journals (Sweden)

    Jânio Araruna Carvalho

    2012-02-01

    Full Text Available OBJETIVO: Identificar como os simuladores estão sendo usados para ensino, treinamento, terapia e exames na medicina, com destaque para oftalmologia. A realidade virtual surgiu como uma ferramenta auxiliar no ensino e treinamento médico. Na oftalmologia, o progresso dessa técnica tem sido publicado em algumas revistas de saúde. Baseado nessas fontes, investigamos como a Oftalmologia tem interagido com a Realidade Virtual, essa ferramenta que veio para auxiliar o ensino da Medicina. MÉTODOS: Revisão sistemática de artigos das principais revistas, além de livros sobre o assunto entre 1995 e 2010. Revisamos a literatura publicada dos últimos quinze anos baseados em referências mencionadas em várias revistas, como exemplo podemos citar a Medical Education, Journal of the American College of Surgeon, Computers & Graphics, New England Journal of Medicine, Proceedingof the IEEE no período de 1990 a 2010. RESULTADOS: Após a revisão de 200 artigos encontrados sobre o tema educação médica e realidade virtual publicados em revistas nacionais e internacionais entre os anos de 1995 e 2010, percebemos as diferenças entre as áreas da medicina, no que se refere ao uso da realidade virtual (RV. Apenas 10 artigos explicitam com algum aprofundamento os simuladores oftalmológicos. CONCLUSÃO: A oftalmologia é uma das áreas que menos interagem com a realidade virtual, devido a dificuldades de montagem de imagens para serem aplicadas no simulador. Mas é uma das áreas que mais precisa, devido à delicadeza da estrutura de trabalho, olho humano. Assim, a Realidade Virtual (RV tem aparecido na otoscopia virtual e na formação dos atlas virtuais. Na cirurgia, os simuladores ainda são poucos, mas provavelmente será a área mais promissora, devido as vantagens do treinamento virtual. Assim, a RV tem surgido junto aos serious games, ensino e treinamento de oftalmologia, além de terapia de fobias.

  16. Seguridad en entornos virtuales

    OpenAIRE

    Echaiz, Javier; Ardenghi, Jorge Raúl

    2009-01-01

    En un entorno virtual, un monitor de maquina virtual (VMM) controla múltiples VMs mediante una abstracción de software del hardware subyacente. Esta arquitectura provee algunas ventajas con respecto a la seguridad pero también introduce desafíos únicos. Irónicamente los avances en la potencia de cómputo y la disminución de los costos del hardware fueron los factores que dieron origen a la pérdida de interés en la virtualización, hoy principales contribuyentes de su renacimiento. La virtua...

  17. Virtual power plant auctions

    Energy Technology Data Exchange (ETDEWEB)

    Ausubel, Lawrence M.; Cramton, Peter [Department of Economics, University of Maryland, College Park, MD 20742 (United States)

    2010-12-15

    Since their advent in 2001, virtual power plant (VPP) auctions have been implemented widely. In this paper, we describe the simultaneous ascending-clock auction format that has been used for virtually all VPP auctions to date, elaborating on other design choices that most VPP auctions have had in common as well as discussing a few aspects that have varied significantly among VPP auctions. We then evaluate the various objectives of regulators in requiring VPP auctions, concluding that the auctions have been effective devices for facilitating new entry into electricity markets and for developing wholesale power markets. (author)

  18. Virtual realities and education

    Directory of Open Access Journals (Sweden)

    Curcio Igor D.D.

    2016-12-01

    Full Text Available The purpose of this article is to highlight the state of the art of virtual reality, augmented reality, mixed reality technologies and their applications in formal education. We also present a selected list of case studies that prove the utility of these technologies in the context of formal education. Furthermore, as byproduct, the mentioned case studies show also that, although the industry is able to develop very advanced virtual environment technologies, their pedagogical implications are strongly related to a well-designed theoretical framework.

  19. Oftalmologia e realidade virtual

    OpenAIRE

    Carvalho, Jânio Araruna

    2012-01-01

    OBJETIVO: Identificar como os simuladores estão sendo usados para ensino, treinamento, terapia e exames na medicina, com destaque para oftalmologia. A realidade virtual surgiu como uma ferramenta auxiliar no ensino e treinamento médico. Na oftalmologia, o progresso dessa técnica tem sido publicado em algumas revistas de saúde. Baseado nessas fontes, investigamos como a Oftalmologia tem interagido com a Realidade Virtual, essa ferramenta que veio para auxiliar o ensino da Medicina. MÉTODOS: Re...

  20. Coded Network Function Virtualization

    DEFF Research Database (Denmark)

    Al-Shuwaili, A.; Simone, O.; Kliewer, J.

    2016-01-01

    Network function virtualization (NFV) prescribes the instantiation of network functions on general-purpose network devices, such as servers and switches. While yielding a more flexible and cost-effective network architecture, NFV is potentially limited by the fact that commercial off-the-shelf ha......Network function virtualization (NFV) prescribes the instantiation of network functions on general-purpose network devices, such as servers and switches. While yielding a more flexible and cost-effective network architecture, NFV is potentially limited by the fact that commercial off...

  1. The virtual knife

    DEFF Research Database (Denmark)

    Hansen, Mads Fogtmann

    and order books. The Danish Meat Research Institute (DMRI) is currently constructing a representative database of virtual representations of pigs using X-ray Computed Tomography (CT). The database will serve as the foundation for the diversity modeling of pigs and for extracting predictors of quality...... and optimal use. This thesis integrates well-known techniques from the medical image analysis into the development of tools for automated analysis of the morphology of pigs. E.g. elastic image matching has been applied to establish spatial correspondence between the virtual representations of pigs...

  2. Resilient Sensor Networks with Spatiotemporal Interpolation of Missing Sensors: An Example of Space Weather Forecasting by Multiple Satellites.

    Science.gov (United States)

    Tokumitsu, Masahiro; Hasegawa, Keisuke; Ishida, Yoshiteru

    2016-04-15

    This paper attempts to construct a resilient sensor network model with an example of space weather forecasting. The proposed model is based on a dynamic relational network. Space weather forecasting is vital for a satellite operation because an operational team needs to make a decision for providing its satellite service. The proposed model is resilient to failures of sensors or missing data due to the satellite operation. In the proposed model, the missing data of a sensor is interpolated by other sensors associated. This paper demonstrates two examples of space weather forecasting that involves the missing observations in some test cases. In these examples, the sensor network for space weather forecasting continues a diagnosis by replacing faulted sensors with virtual ones. The demonstrations showed that the proposed model is resilient against sensor failures due to suspension of hardware failures or technical reasons.

  3. Sensors in Distributed Mixed Reality Environments

    Directory of Open Access Journals (Sweden)

    Felix Hamza-Lup

    2005-04-01

    Full Text Available A distributed mixed-reality (MR or virtual reality (VR environment implies the cooperative engagement of a set of software and hardware resources. With the advances in sensors and computer networks we have seen an increase in the number of potential MR/VR applications that require large amounts of information from the real world collected through sensors (e.g. position and orientation tracking sensors. These sensors collect data from the real environment in real-time at different locations and a distributed environment connecting them must assure data distribution among collaborative sites at interactive speeds. With the advances in sensor technology, we envision that in future systems a significant amount of data will be collected from sensors and devices attached to the participating nodes This paper proposes a new architecture for sensor based interactive distributed MR/VR environments that falls in-between the atomistic peer-to-peer model and the traditional client-server model. Each node is autonomous and fully manages its resources and connectivity. The dynamic behavior of the nodes is dictated by the human participants that manipulate the sensors attached to these nodes.

  4. Universidades virtuales: ¿aprendizaje real?

    OpenAIRE

    Valenzuela González, Jaime Ricardo

    2000-01-01

    1. Introducción; 2. Modalidades educativas; 3. Concepto y características de las universidades virtuales; 4. Un modelo de universidad virtual; 5. Universidades virtuales ¿aprendizaje real?; 6. Tensiones de las universidades virtuales; 7. Referencias

  5. Corporate Training in Virtual Worlds

    OpenAIRE

    Charles Nebolsky; Nicholas K. Yee; Valery A. Petrushin; Anatole V. Gershman

    2004-01-01

    This paper presents virtual training worlds that are relatively low-cost distributed collaborative learning environments suitable for corporate training. A virtual training world allows a facilitator, experts and trainees communicating and acting in the virtual environment for practicing skills during collaborative problem solving. Using these environments is beneficial to both trainees and corporations. Two system prototypes – the sales training and the leadership training virtual worl...

  6. Corporate Training in Virtual Worlds

    Directory of Open Access Journals (Sweden)

    Charles Nebolsky

    2004-12-01

    Full Text Available This paper presents virtual training worlds that are relatively low-cost distributed collaborative learning environments suitable for corporate training. A virtual training world allows a facilitator, experts and trainees communicating and acting in the virtual environment for practicing skills during collaborative problem solving. Using these environments is beneficial to both trainees and corporations. Two system prototypes – the sales training and the leadership training virtual worlds – are described. The leadership training course design is discussed in details.

  7. CMS Virtual Tour Greece

    CERN Multimedia

    CERN. Geneva

    2014-01-01

    More than 500 high-school students from 7 locations in Greece visit virtually the CMS experiment. Read more about this record-breaking event here: http://home.web.cern.ch/students-educators/updates/2014/02/students-visit-heart-cms-detector

  8. Adapting Virtual Camera Behaviour

    DEFF Research Database (Denmark)

    Burelli, Paolo

    2013-01-01

    In a three-dimensional virtual environment aspects such as narrative and interaction completely depend on the camera since the camera defines the player’s point of view. Most research works in automatic camera control aim to take the control of this aspect from the player to automatically gen...

  9. The Virtual Dressing Room

    DEFF Research Database (Denmark)

    Holte, Michael Boelstoft

    2013-01-01

    This paper presents a review of recent developments and future perspectives, addressing the problem of creating a virtual dressing room. First, we review the current state-of-the-art of exiting solutions and discuss their applicability and limitations. We categorize the exiting solutions into thr...

  10. Laboratorio virtual visual

    OpenAIRE

    Torres Medina, Fernando

    2010-01-01

    Presentación del Laboratorio Virtual Visual destinado a la simulación de algoritmos de visión artificial y procesamiento de imágenes desarrollado en el Grupo de Automática, Robótica y Visión Artificial de la Universidad de Alicante.

  11. Navigation in virtual environments

    Science.gov (United States)

    Arthur, Erik; Hancock, Peter A.; Telke, Susan

    1996-06-01

    Virtual environments show great promise in the area of training. ALthough such synthetic environments project homeomorphic physical representations of real- world layouts, it is not known how individuals develop models to match such environments. To evaluate this process, the present experiment examined the accuracy of triadic representations of objects having learned them previously under different conditions. The layout consisted of four different colored spheres arranged on a flat plane. These objects could be viewed in either a free navigation virtual environment condition (NAV) or a single body position virtual environment condition. The first condition allowed active exploration of the environment while the latter condition allowed the participant only a passive opportunity to observe form a single viewpoint. These viewing conditions were a between-subject variable with ten participants randomly assigned to each condition. Performance was assessed by the response latency to judge the accuracy of a layout of three objects over different rotations. Results showed linear increases in response latency as the rotation angle increased from the initial perspective in SBP condition. The NAV condition did not show a similar effect of rotation angle. These results suggest that the spatial knowledge acquisition from virtual environments through navigation is similar to actual navigation.

  12. Virtual Bridge Design Challenge

    Science.gov (United States)

    Mitts, Charles R.

    2013-01-01

    This design/problem-solving activity challenges students to design a replacement bridge for one that has been designated as either structurally deficient or functionally obsolete. The Aycock MS Technology/STEM Magnet Program Virtual Bridge Design Challenge is an authentic introduction to the engineering design process. It is a socially relevant…

  13. Virtual Libraries: Service Realities.

    Science.gov (United States)

    Novak, Jan

    This paper discusses client service issues to be considered when transitioning to a virtual library situation. Themes related to the transitional nature of society in the knowledge era are presented, including: paradox and a contradictory nature; blurring of boundaries; networks, systems, and holistic thinking; process/not product, becoming/not…

  14. Alice - The Virtual Secretary

    DEFF Research Database (Denmark)

    Hansen, Thomas K.

    2009-01-01

    Animated Agents are increasingly finding their way into computer applications and websites. They create life on the screen for us, attempt to personalize our communication and rather than us being forced to read long website introductions, they can verbally introduce us to the content. One of the...... in order to create Alice – The virtual secretary....

  15. Virtual manufacturing in reality

    Science.gov (United States)

    Papstel, Jyri; Saks, Alo

    2000-10-01

    SMEs play an important role in manufacturing industry. But from time to time there is a shortage in resources to complete the particular order in time. Number of systems is introduced to produce digital information in order to support product and process development activities. Main problem is lack of opportunity for direct data transition within design system modules when needed temporary extension of design capacity (virtuality) or to implement integrated concurrent product development principles. The planning experience in the field is weakly used as well. The concept of virtual manufacturing is a supporting idea to solve this problem. At the same time a number of practical problems should be solved like information conformity, data transfer, unified technological concepts acceptation etc. In the present paper the proposed ways to solve the practical problems of virtual manufacturing are described. General objective is to introduce the knowledge-based CAPP system as missing module for Virtual Manufacturing in the selected product domain. Surface-centered planning concept based on STEP- based modeling principles, and knowledge-based process planning methodology will be used to gain the objectives. As a result the planning module supplied by design data with direct access, and supporting advising environment is expected. Mould producing SME would be as test basis.

  16. Finite Virtual State Machines

    OpenAIRE

    Senhadji Navarro, Raouf; García Vargas, Ignacio

    2012-01-01

    This letter proposes a new model of state machine called Finite Virtual State Machine (FVSM). A memory-based architecture and a procedure for generating FVSM implementations from Finite State Machines (FSMs) are presented. FVSM implementations provide advantages in speed over conventional RAM-based FSM implementations. The results of experiments prove the feasibility of this approach.

  17. Virtual Environments 2005

    DEFF Research Database (Denmark)

    This book contains the proceedings of the joint 9th International Immersive Projection Technologies Workshop and the 11th EUROGRAPHICS Virtual Environments Workshop (IPTEGVE). The event was held in Aalborg, Denmark the 6. and 7. October 2005. It was organized at the VR Media Lab, Aalborg University...

  18. A realidade do virtual

    Directory of Open Access Journals (Sweden)

    Eduardo Simonini Lopes

    2005-06-01

    Full Text Available O presente trabalho propõe discutir o conceito de virtual, tendocomo apoio as obras de Pierre Lévy, Jean Baudrillard e Gilles Deleuze.Entendemos que diferentes propostas de realidade do virtualsurgem baseando-se na abordagem de cada um desses autores. E cadauma dessas propostas abre novas perspectivas para o pensamentode enxergar e manipular o conceito de virtual. Partimos, então,neste trabalho, do entendimento do virtual conquanto entidadedesterritorializada (Lévy, 1998, seguindo até sua compreensãoenquanto espaço de potência (Deleuze, 1996. Cada uma dessasabordagens produz um modo de pensar, e, enquanto Lévy situa ovirtual como o espaço de representação da consciência humana,Deleuze já o trabalha como dimensão de intensidades não representacionais, promotora de contínua diferença. Construímos, assim, uma reflexão sobre o modo como alguns pensadores têm trabalhadoo conceito de virtual: utilizando-o como recognição e ignorandoseu entendimento como potência.

  19. Virtual Worlds in Computing Education

    Science.gov (United States)

    Crellin, Jonathan; Duke-Williams, Emma; Chandler, Jane; Collinson, Timothy

    2009-01-01

    This article reports on the use of a virtual world ("Second Life") in computing education, and identifies the precursors of current virtual world systems. The article reviews the potential for virtual worlds as tools in computing education. It describes two areas where "Second Life" has been used in computing education: as a…

  20. Interacting with a Virtual Conductor

    NARCIS (Netherlands)

    Bos, P.; Reidsma, Dennis; Ruttkay, Z.M.; Nijholt, Antinus; Harper, R.; Rauterberg, M; Combetto, M.

    This paper presents a virtual embodied agent that can conduct musicians in a live performance. The virtual conductor conducts music specified by a MIDI file and uses input from a microphone to react to the tempo of the musicians. The current implementation of the virtual conductor can interact with

  1. Ethnography in a Virtual World

    Science.gov (United States)

    Shumar, Wesley; Madison, Nora

    2013-01-01

    This article situates the discussion of virtual ethnography within the larger political/economic changes of twenty-first century consumer capitalism and suggests that increasingly our entire social world is a virtual world and that there were very particular utopian and dystopian framings of virtual community growing out of that history. The…

  2. A tropical cyclone application for virtual globes

    Science.gov (United States)

    Joseph Turk, F.; Hawkins, Jeff; Richardson, Kim; Surratt, Mindy

    2011-01-01

    Within the past ten years, a wide variety of publicly available environmental satellite-based data have become available to users and gained popular exposure in meteorological applications. For example, the Naval Research Laboratory (NRL) has maintained a well accepted web-based tropical cyclone (TC) website (NRL TC-Web) with a diverse selection of environmental satellite imagery and products covering worldwide tropical cyclones extending back to 1997. The rapid development of virtual globe technologies provides for an effective framework to efficiently demonstrate meteorological and oceanographic concepts to not only specialized weather forecasters but also to students and the general public. With their emphasis upon geolocated data, virtual globes represent the next evolution beyond the traditional web browser by allowing one to define how, where, and when various data are displayed and dynamically updated. In this article, we describe a virtual globe implementation of the NRL TC-Web satellite data processing system. The resulting NRL Tropical Cyclones on Earth (TC-Earth) application is designed to exploit the capabilities of virtual globe technology to facilitate the display, animation, and layering of multiple environmental satellite imaging and sounding sensors for effective visualization of tropical cyclone evolution. As with the NRL TC-Web, the TC-Earth application is a dynamic, realtime application, driven by the locations of active and historical tropical cyclones. TC-Earth has a simple interface that is designed around a series of placemarks that follow the storm track history. The position coordinates along the storm track are used to map-register imagery and subset other types of information, allowing the user a wide range of freedom to choose data types, overlay combinations, and animations with a minimum number of clicks. TC-Earth enables the user to quickly select and navigate to the storm of interest from the multiple TCs active at anytime around

  3. Reconfigurable virtual electrowetting channels.

    Science.gov (United States)

    Banerjee, Ananda; Kreit, Eric; Liu, Yuguang; Heikenfeld, Jason; Papautsky, Ian

    2012-02-21

    Lab-on-a-chip systems rely on several microfluidic paradigms. The first uses a fixed layout of continuous microfluidic channels. Such lab-on-a-chip systems are almost always application specific and far from a true "laboratory." The second involves electrowetting droplet movement (digital microfluidics), and allows two-dimensional computer control of fluidic transport and mixing. The merging of the two paradigms in the form of programmable electrowetting channels takes advantage of both the "continuous" functionality of rigid channels based on which a large number of applications have been developed to date and the "programmable" functionality of digital microfluidics that permits electrical control of on-chip functions. In this work, we demonstrate for the first time programmable formation of virtual microfluidic channels and their continuous operation with pressure driven flows using an electrowetting platform. Experimental, theoretical, and numerical analyses of virtual channel formation with biologically relevant electrolyte solutions and electrically-programmable reconfiguration are presented. We demonstrate that the "wall-less" virtual channels can be formed reliably and rapidly, with propagation rates of 3.5-3.8 mm s(-1). Pressure driven transport in these virtual channels at flow rates up to 100 μL min(-1) is achievable without distortion of the channel shape. We further demonstrate that these virtual channels can be switched on-demand between multiple inputs and outputs. Ultimately, we envision a platform that would provide rapid prototyping of microfluidic concepts and would be capable of a vast library of functions and benefitting applications from clinical diagnostics in resource-limited environments to rapid system prototyping to high throughput pharmaceutical applications.

  4. Planar Hall Effect Sensors for Biodetection

    DEFF Research Database (Denmark)

    Rizzi, Giovanni

    as labels and planar Hall effect bridge (PHEB) magnetic field sensor as readout for the beads. The choice of magnetic beads as label is motivated by the lack of virtually any magnetic background from biological samples. Moreover, magnetic beads can be manipulated via an external magnetic field...... system capable of generating both temperature and concentration gradients over the sensor surface. The temperature and buffer concentration can be varied in order to perform denaturation analysis of the DNA hybrids. In this thesis, this kind assay is tested with temperature varying from 20ºC to 70º...

  5. Optical fibre microwire sensors

    OpenAIRE

    Brambilla, G.; Belal, Mohammad; Jung, Y.; Song, Z.; Xu, F.; Newson, T.P.; Richardson, D.J.

    2011-01-01

    This paper reviews sensing applications of optical fibre microwires and nanowires. In addition to the usual benefits of sensors based on optical fibres, these sensors are extremely compact and have fast response speeds. In this review sensors will be grouped in three categories according to their morphology: linear sensors, resonant sensors and tip sensors. While linear and resonant sensors mainly exploit the fraction of power propagating outside the microwire physical boundary, tip sensors t...

  6. Serious Game and Virtual World Training: Instrumentation and Assessment

    Science.gov (United States)

    2012-12-10

    EEG GSR HRV EYE TRACKING Figure 7. Different Physiological Measures for Collecting Human Data 4.3.1 Etectroencephatography (EEG) One of the more...rate variability ( HRV ) and the galvanic skin response (GSR) have both been shown to indicate stress. Both HRV and GSR are measured with sensors...in Serious Games and Virtual Worlds 4 2.2 Methods of Evaluating Training Effectiveness 5 2.3 Ways of Classifying Knowledge 6 2.4 Categorizing Types

  7. Study on the Virtual Care System for the Elderly

    Directory of Open Access Journals (Sweden)

    Hao Xuetao

    2015-01-01

    Full Text Available The virtual care system for the elderly is designed to make them healthier and safer under the increasingly serious aging situation. By using the image processing, speech recognition and relative sensors based on the intelligent terminals, the system accomplishes six functions: sports statistics, heart rate measurement, drug manager, intelligent navigation home and reminder, SOS voice for help and kitchen reminder. Experiments show that it can provide health analysis and safe tutelage for the elderly comprehensively and accurately.

  8. Virtual Instrument for Emissions Measurement of Internal Combustion Engines

    Directory of Open Access Journals (Sweden)

    Armando Pérez

    2016-01-01

    Full Text Available The gases emissions measurement systems in internal combustion engines are strict and expensive nowadays. For this reason, a virtual instrument was developed to measure the combustion emissions from an internal combustion diesel engine, running with diesel-biodiesel mixtures. This software is called virtual instrument for emissions measurement (VIEM, and it was developed in the platform of LabVIEW 2010® virtual programming. VIEM works with sensors connected to a signal conditioning system, and a data acquisition system is used as interface for a computer in order to measure and monitor in real time the emissions of O2, NO, CO, SO2, and CO2 gases. This paper shows the results of the VIEM programming, the integrated circuits diagrams used for the signal conditioning of sensors, and the sensors characterization of O2, NO, CO, SO2, and CO2. VIEM is a low-cost instrument and is simple and easy to use. Besides, it is scalable, making it flexible and defined by the user.

  9. Virtual Instrument for Emissions Measurement of Internal Combustion Engines.

    Science.gov (United States)

    Pérez, Armando; Ramos, Rogelio; Montero, Gisela; Coronado, Marcos; García, Conrado; Pérez, Rubén

    2016-01-01

    The gases emissions measurement systems in internal combustion engines are strict and expensive nowadays. For this reason, a virtual instrument was developed to measure the combustion emissions from an internal combustion diesel engine, running with diesel-biodiesel mixtures. This software is called virtual instrument for emissions measurement (VIEM), and it was developed in the platform of LabVIEW 2010® virtual programming. VIEM works with sensors connected to a signal conditioning system, and a data acquisition system is used as interface for a computer in order to measure and monitor in real time the emissions of O2, NO, CO, SO2, and CO2 gases. This paper shows the results of the VIEM programming, the integrated circuits diagrams used for the signal conditioning of sensors, and the sensors characterization of O2, NO, CO, SO2, and CO2. VIEM is a low-cost instrument and is simple and easy to use. Besides, it is scalable, making it flexible and defined by the user.

  10. Wave Front Sensor for Solar Concentrator Control

    Science.gov (United States)

    2006-08-31

    absorber used as a model sensor consists of a conical shaped absorber made from one quarter inch (¼”) metal tubing. For actual power conversion, the...tubing would be made from a high temperature metal such as Rhenium or Tungsten. The lens or optic system positions the CCD array to virtual focal...circles to circles with varying amounts of area blackened to represent various stages of misalignment. The experiment proceeded by first using one

  11. Virtual Class Support at the Virtual Machine Level

    DEFF Research Database (Denmark)

    Nielsen, Anders Bach; Ernst, Erik

    2009-01-01

    This paper describes how virtual classes can be supported in a virtual machine.  Main-stream virtual machines such as the Java Virtual Machine and the .NET platform dominate the world today, and many languages are being executed on these virtual machines even though their embodied design choices...... conflict with the design choices of the virtual machine.  For instance, there is a non-trivial mismatch between the main-stream virtual machines mentioned above and dynamically typed languages.  One language concept that creates an even greater mismatch is virtual classes, in particular because fully...... general support for virtual classes requires generation of new classes at run-time by mixin composition.  Languages like CaesarJ and ObjectTeams can express virtual classes restricted to the subset that does not require run-time generation of classes, because of the restrictions imposed by the Java...

  12. Innovative application of virtual display technique in virtual museum

    Science.gov (United States)

    Zhang, Jiankang

    2017-09-01

    Virtual museum refers to display and simulate the functions of real museum on the Internet in the form of 3 Dimensions virtual reality by applying interactive programs. Based on Virtual Reality Modeling Language, virtual museum building and its effective interaction with the offline museum lie in making full use of 3 Dimensions panorama technique, virtual reality technique and augmented reality technique, and innovatively taking advantages of dynamic environment modeling technique, real-time 3 Dimensions graphics generating technique, system integration technique and other key virtual reality techniques to make sure the overall design of virtual museum.3 Dimensions panorama technique, also known as panoramic photography or virtual reality, is a technique based on static images of the reality. Virtual reality technique is a kind of computer simulation system which can create and experience the interactive 3 Dimensions dynamic visual world. Augmented reality, also known as mixed reality, is a technique which simulates and mixes the information (visual, sound, taste, touch, etc.) that is difficult for human to experience in reality. These technologies make virtual museum come true. It will not only bring better experience and convenience to the public, but also be conducive to improve the influence and cultural functions of the real museum.

  13. Corrosion sensor

    Science.gov (United States)

    Glass, Robert S.; Clarke, Jr., Willis L.; Ciarlo, Dino R.

    1994-01-01

    A corrosion sensor array incorporating individual elements for measuring various elements and ions, such as chloride, sulfide, copper, hydrogen (pH), etc. and elements for evaluating the instantaneous corrosion properties of structural materials. The exact combination and number of elements measured or monitored would depend upon the environmental conditions and materials used which are subject to corrosive effects. Such a corrosion monitoring system embedded in or mounted on a structure exposed to the environment would serve as an early warning system for the onset of severe corrosion problems for the structure, thus providing a safety factor as well as economic factors. The sensor array is accessed to an electronics/computational system, which provides a means for data collection and analysis.

  14. Pressure sensor

    Science.gov (United States)

    Mee, David K.; Ripley, Edward B.; Nienstedt, Zachary C.; Nienstedt, Alex W.; Howell, Jr., Layton N.

    2015-09-29

    Disclosed is a passive, in-situ pressure sensor. The sensor includes a sensing element having a ferromagnetic metal and a tension inducing mechanism coupled to the ferromagnetic metal. The tension inducing mechanism is operable to change a tensile stress upon the ferromagnetic metal based on a change in pressure in the sensing element. Changes in pressure are detected based on changes in the magnetic switching characteristics of the ferromagnetic metal when subjected to an alternating magnetic field caused by the change in the tensile stress. The sensing element is embeddable in a closed system for detecting pressure changes without the need for any penetrations of the system for power or data acquisition by detecting changes in the magnetic switching characteristics of the ferromagnetic metal caused by the tensile stress.

  15. Virtual vitreoretinal surgery

    DEFF Research Database (Denmark)

    Vergmann, Anna Stage; Vestergaard, Anders Højslet; Grauslund, Jakob

    2017-01-01

    PURPOSE: To test the validity of the eyesi surgical simulator as an assessment tool in a virtual reality vitreoretinal training programme. METHODS: In collaboration with an experienced vitreoretinal surgeon, a virtual vitreoretinal training programme was composed on the eyesi surgical simulator......, software version 2.9.2 (VRmagic GmbH, Manheim, Germany). It was completed twice by three groups: 20 medical students, ten residents of ophthalmology and five trained vitreoretinal surgeons. The programme contained six training modules: navigation level 2 (Nav2), forceps training level 5 (ForT5), bimanual...... training level 3 (BimT3), laser coagulation level 3 (LasC3), posterior hyaloid level 3 (PostH3) and internal limiting membrane peeling level 3 (ILMP3). The scores in each module were assessed from two to five different factors (tissue treatment, efficiency, target achievement, instrument handling...

  16. Curating Virtual Data Collections

    Science.gov (United States)

    Lynnes, Chris; Leon, Amanda; Ramapriyan, Hampapuram; Tsontos, Vardis; Shie, Chung-Lin; Liu, Zhong

    2015-01-01

    NASAs Earth Observing System Data and Information System (EOSDIS) contains a rich set of datasets and related services throughout its many elements. As a result, locating all the EOSDIS data and related resources relevant to particular science theme can be daunting. This is largely because EOSDIS data's organizing principle is affected more by the way they are produced than around the expected end use. Virtual collections oriented around science themes can overcome this by presenting collections of data and related resources that are organized around the user's interest, not around the way the data were produced. Virtual collections consist of annotated web addresses (URLs) that point to data and related resource addresses, thus avoiding the need to copy all of the relevant data to a single place. These URL addresses can be consumed by a variety of clients, ranging from basic URL downloaders (wget, curl) and web browsers to sophisticated data analysis programs such as the Integrated Data Viewer.

  17. The Herbert Virtual Museum

    Directory of Open Access Journals (Sweden)

    Panagiotis Petridis

    2013-01-01

    Full Text Available In recent years, virtual reality and augmented reality have emerged as areas of extreme interest as unique methods for visualising and interacting with digital museum artefacts in a different context, for example, as a virtual museum or exhibition, particularly over the Internet. Modern cultural heritage exhibitions have evolved from static to dynamic exhibitions and challenging explorations. This paper presents two different applications developed for the Herbert Museum and Art Gallery that make the user’s experience more immersive, engaging, and interactive. The first application utilizes mobile phone devices in order to enrich the visitors experience in the museum, and the second application is a serious game for cultural heritage and in particular for museum environments focusing on the younger visitors.

  18. Cuenca, realidad virtual

    Directory of Open Access Journals (Sweden)

    Concepción Rodríguez Ruza

    2012-11-01

    Full Text Available This project, Cuenca, realidad virtual, was created so that the key periods of the historical evolution of Cuenca could be explained, where the Islamic Cuenca, Christian Cuenca and Cuenca in the 18th Century are comprised. The reconstruction of these different ages is represented by different routes through a threedimensional environment by means of this application .In order to be put into practice, 3D geometries, 3D polygon models, texturin, 3D illumination and threedimensional geometries animation of all of these elements have been implemented. Virtual visits are introduced by some texts, hearings, plans, archive and current pictures. These routes allow the visitor to get to know the past of this town through a recreational and easy going method

  19. Virtual reality systems

    Science.gov (United States)

    Johnson, David W.

    1992-01-01

    Virtual realities are a type of human-computer interface (HCI) and as such may be understood from a historical perspective. In the earliest era, the computer was a very simple, straightforward machine. Interaction was human manipulation of an inanimate object, little more than the provision of an explicit instruction set to be carried out without deviation. In short, control resided with the user. In the second era of HCI, some level of intelligence and control was imparted to the system to enable a dialogue with the user. Simple context sensitive help systems are early examples, while more sophisticated expert system designs typify this era. Control was shared more equally. In this, the third era of the HCI, the constructed system emulates a particular environment, constructed with rules and knowledge about 'reality'. Control is, in part, outside the realm of the human-computer dialogue. Virtual reality systems are discussed.

  20. Virtual team collaboration

    DEFF Research Database (Denmark)

    Bjørn, Pernille; Ngwenyama, Ojelanki

    2009-01-01

    as the foundation for building shared meaning at three levels. Also we investigate communication breakdowns that can be attributed to differences in lifeworld structures, organizational structures, and work process structures within a virtual team. We find that all communication breakdowns are manifested...... and experienced by the participants at the work process level; however, resolving breakdowns may require critical reflection at other levels. Where previous research argues that face-to-face interaction is an important variable for virtual team performance, our empirical observations reveal that communication......Managing international teams with geographically distributed participants is a complex task. The risk of communication breakdowns increases due to cultural and organizational differences grounded in the geographical distribution of the participants. Such breakdowns indicate general...

  1. Integration Of Sensor Orientation Data Into An Augmented Reality Technology

    Directory of Open Access Journals (Sweden)

    Edgaras Artemčiukas

    2014-05-01

    Full Text Available Currently, such microelectromechanical sensors as accelerome­ters, gyroscopes and magnetometers are the dominant sensors in mobile devices. The market of mobile devices is constantly expanding and focused on sensor integration process by adding supplementary functionality for the applications; therefore, it is possible to adapt these sensors for augmented reality technology solutions. Many augmented reality solutions are based on computer vision processing methods in order to identify and track markers or other objects. However, the main problem is chaotic environment, lighting conditions where object recognition and tracking in real-time becomes difficult and sometimes is an impossible process. This paper analyses possibilities to apply microelectromechanical sensors. Additionally, it investigates quaternion use for sensor data to estimate reliable and accurate camera orientation and represent virtual content in augmented reality technology.

  2. Cyber Operations Virtual Environment

    Science.gov (United States)

    2010-09-01

    AFRL-RH-AZ-TR-2010-0027 Cyber Operations Virtual Environment Jennifer L. Winner Lisa S. Holt Jasmine Duran Eric Watz Lumir Research...CONTRACT NUMBER FA8650-05-D-6502 5b. GRANT NUMBER N/A 5c. PROGRAM ELEMENT NUMBER 63227F 6. AUTHOR(S) Jennifer L. Winner Lisa S. Holt Jasmine Duran...performance of individuals and that of teams. Knowledge elicitation methods like Pathfinder and Air Superiority Knowledge Assessment System (ASKAS

  3. Play and virtuality

    Directory of Open Access Journals (Sweden)

    Svein Sando

    2010-07-01

    Full Text Available The similarities between virtuality and play are obvious, beginning with, for instance, the ubiquitous character of both. This paper deals with how insights from research on play can be used to enlighten our understanding of the ethical dimensions of activities in cyberspace, and vice versa. In particular, a central claim that play is beyond vice and virtue is debated and contested.http://dx.doi.org/10.5324/eip.v4i2.1762

  4. Virtual Personal Assistant

    OpenAIRE

    Imrie, Peter; Bednar, Peter

    2013-01-01

    Abstract This report discusses ways in which new technology could be harnessed to create an intelligent Virtual Personal Assistant (VPA) with a focus on user-based information. It will look at examples of intelligent programs with natural language processing that are currently available, with different categories of support, and examine the potential usefulness of one specific piece of software as a VPA. This engages the ability to communicate socially through natural language processing, hol...

  5. Droni e turismo virtuale

    Directory of Open Access Journals (Sweden)

    Valeria Minucciani

    2015-08-01

    Full Text Available Virtual tourism has been through at least three generations.The first is a special form of e-commerce, and no doubt it has much changed the way you plan your travel. Second generation of virtual tourism has exploited georeference: the user can know the services offered nearby and, with appropriate apps and augmented reality, receive information about places.An important contribution has been made in this field by social media (see Flickr, as well as Tripadvisor. The third generation of virtual tourism even replaces the travel experience: first proposing visits in virtual worlds, then in the real world. That allows tourism to social classes that are excluded.The goal is to send in the real place an "avatar", that can perform what tourist wants. Some experiments have been recently performed with robots, here a visit by drones is proposed. In particular, indoor visits are difficult because it is necessary to re-create a microgeodetic reference system in a closed and confined environment, to allow remote control and to ensure the protection of the cultural property. It has also to be considered the issue of the size of the drone, its autonomy and shooting video (which must be 360 degrees and high definition.The real experience is irreplaceable, but this form of tourism can find many interesting applications and strengthen real tourism.In conclusion, we believe that not only this performances are now within the reach of our technical capabilities, but  they also represent an effective response to certain social and cultural issues. 

  6. Droni e turismo virtuale

    Directory of Open Access Journals (Sweden)

    Valeria Minucciani

    2015-08-01

    Full Text Available Virtual tourism has been through at least three generations. The first is a special form of e-commerce, and no doubt it has much changed the way you plan your travel. Second generation of virtual tourism has exploited georeference: the user can know the services offered nearby and, with appropriate apps and augmented reality, receive information about places. An important contribution has been made in this field by social media (see Flickr, as well as Tripadvisor. The third generation of virtual tourism even replaces the travel experience: first proposing visits in virtual worlds, then in the real world. That allows tourism to social classes that are excluded. The goal is to send in the real place an "avatar", that can perform what tourist wants. Some experiments have been recently performed with robots, here a visit by drones is proposed. In particular, indoor visits are difficult because it is necessary to re-create a microgeodetic reference system in a closed and confined environment, to allow remote control and to ensure the protection of the cultural property. It has also to be considered the issue of the size of the drone, its autonomy and shooting video (which must be 360 degrees and high definition. The real experience is irreplaceable, but this form of tourism can find many interesting applications and strengthen real tourism. In conclusion, we believe that not only this performances are now within the reach of our technical capabilities, but  they also represent an effective response to certain social and cultural issues.

  7. File System Virtual Appliances

    Science.gov (United States)

    2010-05-01

    version. The result is over 300 configurations. 14 · File system virtual appliances Type Description Memory Pressure Some RedHat Enterprise Linux 3 kernels...blocking. This results in minutes-long de- lays in dirty data writeback under low memory situations. RedHat acknowledged the semantic mismatch but did not...ten. This caused a file system to mistakenly assume that all pages were written, resulting in data corruption. Stack Size RedHat Enterprise Linux

  8. Virtual Quantum Subsystems

    OpenAIRE

    Zanardi, Paolo

    2001-01-01

    The physical resources available to access and manipulate the degrees of freedom of a quantum system define the set $\\cal A$ of operationally relevant observables. The algebraic structure of $\\cal A$ selects a preferred tensor product structure i.e., a partition into subsystems. The notion of compoundness for quantum system is accordingly relativized. Universal control over virtual subsystems can be achieved by using quantum noncommutative holonomies

  9. Virtual Quantum Subsystems

    Energy Technology Data Exchange (ETDEWEB)

    Zanardi, Paolo

    2001-08-13

    The physical resources available to access and manipulate the degrees of freedom of a quantum system define the set A of operationally relevant observables. The algebraic structure of A selects a preferred tensor product structure, i.e., a partition into subsystems. The notion of compoundness for quantum systems is accordingly relativized. Universal control over virtual subsystems can be achieved by using quantum noncommutative holonomies

  10. Virtual nuclear weapons

    Energy Technology Data Exchange (ETDEWEB)

    Pilat, J.F.

    1997-08-01

    The term virtual nuclear weapons proliferation and arsenals, as opposed to actual weapons and arsenals, has entered in recent years the American lexicon of nuclear strategy, arms control, and nonproliferation. While the term seems to have an intuitive appeal, largely due to its cyberspace imagery, its current use is still vague and loose. The author believes, however, that if the term is clearly delineated, it might offer a promising approach to conceptualizing certain current problems of proliferation. The first use is in a reference to an old problem that has resurfaced recently: the problem of growing availability of weapon-usable nuclear materials in civilian nuclear programs along with materials made `excess` to defense needs by current arms reduction and dismantlement. It is argued that the availability of these vast materials, either by declared nuclear-weapon states or by technologically advanced nonweapon states, makes it possible for those states to rapidly assemble and deploy nuclear weapons. The second use has quite a different set of connotations. It is derived conceptually from the imagery of computer-generated reality. In this use, one thinks of virtual proliferation and arsenals not in terms of the physical hardware required to make the bomb but rather in terms of the knowledge/experience required to design, assemble, and deploy the arsenal. Virtual weapons are a physics reality and cannot be ignored in a world where knowledge, experience, materials, and other requirements to make nuclear weapons are widespread, and where dramatic army reductions and, in some cases, disarmament are realities. These concepts are useful in defining a continuum of virtual capabilities, ranging from those at the low end that derive from general technology diffusion and the existence of nuclear energy programs to those at the high end that involve conscious decisions to develop or maintain militarily significant nuclear-weapon capabilities.

  11. Virtual Reality in Neurorehabilitation

    OpenAIRE

    Stasieńko Agnieszka; Sarzyńska-Długosz Iwona

    2016-01-01

    This article includes current information on the use of modern IT solutions and virtual-reality (VR)-based technologies in medical rehabilitation. A review of current literature on VR-based interventions and their indications, benefits and limitations in patients with nervous system diseases was conducted. The popularity of VR-based training as a tool used for rehabilitation of patients with acute and chronic deficits in both sensory-motor and cognitive disorders is increasing. Still, there i...

  12. Evaluation of Sensor Configurations for Robotic Surgical Instruments

    Science.gov (United States)

    Gómez-de-Gabriel, Jesús M.; Harwin, William

    2015-01-01

    Designing surgical instruments for robotic-assisted minimally-invasive surgery (RAMIS) is challenging due to constraints on the number and type of sensors imposed by considerations such as space or the need for sterilization. A new method for evaluating the usability of virtual teleoperated surgical instruments based on virtual sensors is presented. This method uses virtual prototyping of the surgical instrument with a dual physical interaction, which allows testing of different sensor configurations in a real environment. Moreover, the proposed approach has been applied to the evaluation of prototypes of a two-finger grasper for lump detection by remote pinching. In this example, the usability of a set of five different sensor configurations, with a different number of force sensors, is evaluated in terms of quantitative and qualitative measures in clinical experiments with 23 volunteers. As a result, the smallest number of force sensors needed in the surgical instrument that ensures the usability of the device can be determined. The details of the experimental setup are also included. PMID:26516863

  13. Evaluation of Sensor Configurations for Robotic Surgical Instruments.

    Science.gov (United States)

    Gómez-de-Gabriel, Jesús M; Harwin, William

    2015-10-27

    Designing surgical instruments for robotic-assisted minimally-invasive surgery (RAMIS) is challenging due to constraints on the number and type of sensors imposed by considerations such as space or the need for sterilization. A new method for evaluating the usability of virtual teleoperated surgical instruments based on virtual sensors is presented. This method uses virtual prototyping of the surgical instrument with a dual physical interaction, which allows testing of different sensor configurations in a real environment. Moreover, the proposed approach has been applied to the evaluation of prototypes of a two-finger grasper for lump detection by remote pinching. In this example, the usability of a set of five different sensor configurations, with a different number of force sensors, is evaluated in terms of quantitative and qualitative measures in clinical experiments with 23 volunteers. As a result, the smallest number of force sensors needed in the surgical instrument that ensures the usability of the device can be determined. The details of the experimental setup are also included.

  14. Evaluation of Sensor Configurations for Robotic Surgical Instruments

    Directory of Open Access Journals (Sweden)

    Jesús M. Gómez-de-Gabriel

    2015-10-01

    Full Text Available Designing surgical instruments for robotic-assisted minimally-invasive surgery (RAMIS is challenging due to constraints on the number and type of sensors imposed by considerations such as space or the need for sterilization. A new method for evaluating the usability of virtual teleoperated surgical instruments based on virtual sensors is presented. This method uses virtual prototyping of the surgical instrument with a dual physical interaction, which allows testing of different sensor configurations in a real environment. Moreover, the proposed approach has been applied to the evaluation of prototypes of a two-finger grasper for lump detection by remote pinching. In this example, the usability of a set of five different sensor configurations, with a different number of force sensors, is evaluated in terms of quantitative and qualitative measures in clinical experiments with 23 volunteers. As a result, the smallest number of force sensors needed in the surgical instrument that ensures the usability of the device can be determined. The details of the experimental setup are also included.

  15. Virtual blood bank

    Directory of Open Access Journals (Sweden)

    Kit Fai Wong

    2011-01-01

    Full Text Available Virtual blood bank is the computer-controlled, electronically linked information management system that allows online ordering and real-time, remote delivery of blood for transfusion. It connects the site of testing to the point of care at a remote site in a real-time fashion with networked computers thus maintaining the integrity of immunohematology test results. It has taken the advantages of information and communication technologies to ensure the accuracy of patient, specimen and blood component identification and to enhance personnel traceability and system security. The built-in logics and process constraints in the design of the virtual blood bank can guide the selection of appropriate blood and minimize transfusion risk. The quality of blood inventory is ascertained and monitored, and an audit trail for critical procedures in the transfusion process is provided by the paperless system. Thus, the virtual blood bank can help ensure that the right patient receives the right amount of the right blood component at the right time.

  16. Medical Virtual Public Services

    Directory of Open Access Journals (Sweden)

    Iulia SURUGIU

    2008-01-01

    Full Text Available The healthcare enterprises are very disconnected. This paper intends to propose a solution that will provide citizens, businesses and medical enterprises with improved access to medical virtual public services. Referred medical services are based on existing national medical Web services and which support medically required services provided by physicians and supplementary health care practitioners, laboratory services and diagnostic procedures, clinics and hospitals’ services. Requirements and specific rules of these medical services are considered, and personalization of user preferences will to be supported. The architecture is based on adaptable process management technologies, allowing for virtual services which are dynamically combined from existing national medical services. In this way, a comprehensive workflow process is set up, allowing for service-level agreements, an audit trail and explanation of the process to the end user. The process engine operates on top of a virtual repository, providing a high-level semantic view of information retrieved from heterogeneous information sources, such as national sources of medical services. The system relies on a security framework to ensure all high-level security requirements are met. System’s architecture is business oriented: it focuses on Service Oriented Architecture - SOA concepts, asynchronously combining Web services, Business Process Management – BPM rules and BPEL standards.

  17. Workflow-Oriented Cyberinfrastructure for Sensor Data Analytics

    Science.gov (United States)

    Orcutt, J. A.; Rajasekar, A.; Moore, R. W.; Vernon, F.

    2015-12-01

    Sensor streams comprise an increasingly large part of Earth Science data. Analytics based on sensor data require an easy way to perform operations such as acquisition, conversion to physical units, metadata linking, sensor fusion, analysis and visualization on distributed sensor streams. Furthermore, embedding real-time sensor data into scientific workflows is of growing interest. We have implemented a scalable networked architecture that can be used to dynamically access packets of data in a stream from multiple sensors, and perform synthesis and analysis across a distributed network. Our system is based on the integrated Rule Oriented Data System (irods.org), which accesses sensor data from the Antelope Real Time Data System (brtt.com), and provides virtualized access to collections of data streams. We integrate real-time data streaming from different sources, collected for different purposes, on different time and spatial scales, and sensed by different methods. iRODS, noted for its policy-oriented data management, brings to sensor processing features and facilities such as single sign-on, third party access control lists ( ACLs), location transparency, logical resource naming, and server-side modeling capabilities while reducing the burden on sensor network operators. Rich integrated metadata support also makes it straightforward to discover data streams of interest and maintain data provenance. The workflow support in iRODS readily integrates sensor processing into any analytical pipeline. The system is developed as part of the NSF-funded Datanet Federation Consortium (datafed.org). APIs for selecting, opening, reaping and closing sensor streams are provided, along with other helper functions to associate metadata and convert sensor packets into NetCDF and JSON formats. Near real-time sensor data including seismic sensors, environmental sensors, LIDAR and video streams are available through this interface. A system for archiving sensor data and metadata in Net

  18. Realistic Visualization of Virtual Views and Virtual Cinema

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    2005-01-01

    Realistic Virtual View Visualization is a new field of research which has received increasing attention in recent years. It is strictly related to the increased popularity of virtual reality and the spread of its applications, among which virtual photography and cinematography. The use of computer...... generated characters, "virtual actors", in the motion picture production increases every day. While the most known computer graphics techniques have largely been adopted successfully in nowadays fictions, it still remains very challenging to implement virtual actors which would resemble, visually, human...... beings. Interestingly, film directors have been looking at the recent progress achieved by the research community in the field of realistic visualization of virtual views, and they have successfully implemented state of the art research approaches in their productions. An innovative concept...

  19. Greener Aviation with Virtual Sensors: A Case Study

    Data.gov (United States)

    National Aeronautics and Space Administration — The environmental impact of aviation is enormous given the fact that in the US alone there are nearly 6 million flights per year of commercial aircraft. This...

  20. Virtual Place Value

    Science.gov (United States)

    Burris, Justin T.

    2013-01-01

    Technology permeates every aspect of daily life, from the sensors that control the traffic signals to the cameras that allow real-time video chats with family around the world. At times, technology may make life easier, faster, and more productive. However, does technology do the same in schools and classrooms? Will the benefits of technology…

  1. Virtual Reality for Anxiety Disorders

    Directory of Open Access Journals (Sweden)

    Elif Uzumcu

    2018-03-01

    Full Text Available Virtual reality is a relatively new exposure tool that uses three-dimensional computer-graphics-based technologies which allow the individual to feel as if they are physically inside the virtual environment by misleading their senses. As virtual reality studies have become popular in the field of clinical psychology in recent years, it has been observed that virtual-reality-based therapies have a wide range of application areas, especially on anxiety disorders. Studies indicate that virtual reality can be more realistic than mental imagery and can create a stronger feeling of ԰resenceԻ that it is a safer starting point compared to in vivo exposure; and that it can be applied in a more practical and controlled manner. The aim of this review is to investigate exposure studies based on virtual reality in anxiety disorders (specific phobias, panic disorder and agoraphobias, generalized anxiety disorder, social phobia, posttraumatic stress disorder and obsessive compulsive disorder.

  2. The ethnography of virtual reality

    Directory of Open Access Journals (Sweden)

    Gavrilović Ljiljana 1

    2004-01-01

    Full Text Available This paper discusses possible application of ethnographic research in the realm of virtual reality, especially in the relationship between cultures in virtual communities. This represents an entirely new area of ethnographic research and therefore many adjustments in the research design are needed for example, a development of a specific method of data gathering and tools for their verification. A virtual, cyber space is a version of social space more or less synchronous with it, but without the, "real", that is, physical presence of the people who create it. This virtual reality, defined and bounded by virtual space, is in fact real - and though we are not able to observe real, physical parameters of its existence, we can perceive its consequences. In sum, an innovative ethnographic research method is fully applicable for exploring the realm of virtual reality; in order to do so we need to expand, in addition to the new research design and methods, the field of science itself.

  3. Virtual reality technology and applications

    CERN Document Server

    Mihelj, Matjaž; Beguš, Samo

    2014-01-01

    As virtual reality expands from the imaginary worlds of science fiction and pervades every corner of everyday life, it is becoming increasingly important for students and professionals alike to understand the diverse aspects of this technology. This book aims to provide a comprehensive guide to the theoretical and practical elements of virtual reality, from the mathematical and technological foundations of virtual worlds to the human factors and the applications that enrich our lives: in the fields of medicine, entertainment, education and others. After providing a brief introduction to the topic, the book describes the kinematic and dynamic mathematical models of virtual worlds. It explores the many ways a computer can track and interpret human movement, then progresses through the modalities that make up a virtual world: visual, acoustic and haptic. It explores the interaction between the actual and virtual environments, as well as design principles of the latter. The book closes with an examination of diff...

  4. Hydrogen sensor

    Science.gov (United States)

    Duan, Yixiang; Jia, Quanxi; Cao, Wenqing

    2010-11-23

    A hydrogen sensor for detecting/quantitating hydrogen and hydrogen isotopes includes a sampling line and a microplasma generator that excites hydrogen from a gas sample and produces light emission from excited hydrogen. A power supply provides power to the microplasma generator, and a spectrometer generates an emission spectrum from the light emission. A programmable computer is adapted for determining whether or not the gas sample includes hydrogen, and for quantitating the amount of hydrogen and/or hydrogen isotopes are present in the gas sample.

  5. The photon: A virtual reality

    OpenAIRE

    Andrews, D.L.

    2008-01-01

    It has been observed that every photon is, in a sense, virtual - being emitted and then sooner or later absorbed. As the motif of a quantum radiation state, the photon shares these characteristics of any virtual state: that it is not directly observable; and that it can signify only one of a number of indeterminable intermediates, between matter states that are directly measurable. Nonetheless, other traits of real and virtual behavior are usually quite clearly differentiable. How 'real', the...

  6. Virtual Vertical Aircraft Signal Training

    National Research Council Canada - National Science Library

    Norling, William

    1998-01-01

    .... Advances in virtual environments may provide a cost effective solution to the current live helicopter operations method of training, provided technical issues associated with hand and wand signal...

  7. Virtual corporations, enterprise and organisation

    Directory of Open Access Journals (Sweden)

    Carmen RÃDUT

    2009-06-01

    Full Text Available Virtual organisation is a strategic paradigm that is centred on the use of information and ICT to create value. Virtual organisation is presented as a metamanagement strategy that has application in all value oriented organisations. Within the concept of Virtual organisation, the business model is an ICT based construct that bridges and integrates enterprise strategic and operational concerns. Firms try to ameliorate the impacts of risk and product complexity by forming alliances and partnerships with others to spread the risk of new products and new ventures and to increase organisational competence. The result is a networked virtual organization.

  8. Mobile Virtual Private Networking

    Science.gov (United States)

    Pulkkis, Göran; Grahn, Kaj; Mårtens, Mathias; Mattsson, Jonny

    Mobile Virtual Private Networking (VPN) solutions based on the Internet Security Protocol (IPSec), Transport Layer Security/Secure Socket Layer (SSL/TLS), Secure Shell (SSH), 3G/GPRS cellular networks, Mobile IP, and the presently experimental Host Identity Protocol (HIP) are described, compared and evaluated. Mobile VPN solutions based on HIP are recommended for future networking because of superior processing efficiency and network capacity demand features. Mobile VPN implementation issues associated with the IP protocol versions IPv4 and IPv6 are also evaluated. Mobile VPN implementation experiences are presented and discussed.

  9. Analizar las interacciones virtuales

    Directory of Open Access Journals (Sweden)

    Luis Gómez Encinas

    2003-11-01

    Full Text Available El propósito de este artículo es abordar una serie de cuestiones relacionadas con las interacciones virtuales. En concreto, nos centraremos en el IRC, los comúnmente llamados chats, para a partir de una crítica a ciertos posicionamientos analíticos, expresar la necesidad de indagar en esa faceta del ciberespacio desde el punto de vista de las relaciones sociales. Nuevas relaciones sociales, que acontecen en un espacio nuevo, y que por tanto se desarrollan bajo reglas y motivaciones que desbordan los viejos esquemas de observación.

  10. Reality in Virtual Learning

    DEFF Research Database (Denmark)

    Lindberg, Frank; Pettersson, Michael

    The development of ITC has increased focus onto distance learning programs worldwide. Most universities today offer distance learning programs that are based on the Internet. This development represents a fundamental change in the very logic of being a university. It is no longer enough to rely...... characteristics of the program, however, it is particularly interesting to investigate the role that virtual studying serves in the construction of reality and meaning. Furthermore, as it is assumed that experiences cannot be separated from who one is (being-in-the world), the process of human change during...

  11. Virtual Reality in Neurorehabilitation

    Directory of Open Access Journals (Sweden)

    Stasieńko Agnieszka

    2016-12-01

    Full Text Available This article includes current information on the use of modern IT solutions and virtual-reality (VR-based technologies in medical rehabilitation. A review of current literature on VR-based interventions and their indications, benefits and limitations in patients with nervous system diseases was conducted. The popularity of VR-based training as a tool used for rehabilitation of patients with acute and chronic deficits in both sensory-motor and cognitive disorders is increasing. Still, there is a need for large randomized trials to evaluate the efficacy and safety of VR-based rehabilitation techniques in different disease entities. .

  12. Vibro-acoustic methods for the determination of the technical state of a refrigeration piston compressor. A check-up for the compressor. Vibroakustische Verfahren zur Bestimmung des technischen Zustandes eines Kaeltekolbenverdichters. Ein Check-up fuer den Verdichter

    Energy Technology Data Exchange (ETDEWEB)

    Milowanow, V.I.; Lopatinskaja, E.S.

    1990-10-01

    Independent of the kind of refrigeration plant the actual service life is limited by the service life of the compressor. In case of refrigeration machinery with small-type refrigeration compressors for refrigerated transport systems a periodical check of the system before setting out is particularly important. A spectral analysis process is recommended for the diagnosis. But due to the particularities of the plants this is only suited for systems for vibroacoustic diagnosis. This technique is presented using charts and diagrams. (BWI).

  13. Sensors for Entertainment.

    Science.gov (United States)

    Lamberti, Fabrizio; Sanna, Andrea; Rokne, Jon

    2016-07-15

    Sensors are becoming ubiquitous in all areas of science, technology, and society. In this Special Issue on "Sensors for Entertainment", developments in progress and the current state of application scenarios for sensors in the field of entertainment is explored.

  14. VIRTUAL ETHNOGRAPHY RESEARCH ON SECOND LIFE VIRTUAL COMMUNITIES

    Directory of Open Access Journals (Sweden)

    Mehmet FIRAT

    2011-08-01

    Full Text Available The rise of digital technologies like 3D virtual worlds has the potential to open new directions in virtual ethnography researches. Although there has been a lot of discussion about conducting research in online spaces and in virtual games, there are few studies on conducting research in virtual worlds. In this study, within a holistic perspective, the virtual ethnography research potential in Second Life was investigated vithe the help of a detailed participant observation research conducted by researchers in Second Life and from a holistic perspective. This research was conducted in the fall semester of the 2009-2010 academic years. In this study, researchers in the role of a participant observer conducted 8 observations in ethnographic focus. Also, some important methods and techniques that can be used in doing ethnographic research in Second Life are presented in this study.

  15. Modeling and simulation of TDI CMOS image sensors

    Science.gov (United States)

    Nie, Kai-ming; Yao, Su-ying; Xu, Jiang-tao; Gao, Jing

    2013-09-01

    In this paper, a mathematical model of TDI CMOS image sensors was established in behavioral level through MATLAB based on the principle of a TDI CMOS image sensor using temporal oversampling rolling shutter in the along-track direction. The geometric perspective and light energy transmission relationships between the scene and the image on the sensor are included in the proposed model. A graphical user interface (GUI) of the model was also established. A high resolution satellitic picture was used to model the virtual scene being photographed. The effectiveness of the proposed model was verified by computer simulations based on the satellitic picture. In order to guide the design of TDI CMOS image sensors, the impacts of some parameters of TDI CMOS image sensors including pixel pitch, pixel photosensitive size, and integration time on the performance of the sensors were researched through the proposed model. The impacts of the above parameters on the sensors were quantified by sensor's modulation transfer function (MTF) of the along-track direction, which was calculated by slanted-edge method. The simulation results indicated that the TDI CMOS image sensor can get a better performance with smaller pixel photosensitive size and shorter integration time. The proposed model is useful in the process of researching and developing a TDI CMOS image sensor.

  16. Virtual reality and psychotherapy.

    Science.gov (United States)

    Botella, Cristina; Quero, Soledad; Baños, Rosa M; Perpiñá, Conxa; García Palacios, Azucena; Riva, Giuseppe

    2004-01-01

    Virtual Reality (VR) is a new technology consisting on a graphic environment in which the user, not only has the feeling of being physically present in a virtual world, but he/she can interact with it. The first VR workstations were designed for big companies in order to create environments that simulate certain situations to train professionals. However, at this moment a great expansion of this technology is taking place in several fields, including the area of health. Especially interesting for us is the use of VR as a therapeutic tool in the treatment of psychological disorders. Compared to the traditional treatments, VR has many advantages (e.g., it is a protected environment for the patient, he/she can re-experience many times the feared situation, etc.). There are already data on the effectiveness of this technology in the treatment of different psychological disorders; here anxiety disorders, eating disorders and sexual disorders are reviewed. Finally, this chapter ends with some words about the limitations of VR and future perspectives.

  17. Virtual Optical Comparator

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Greg

    2008-10-20

    The Virtual Optical Comparator, VOC, was conceived as a result of the limitations of conventional optical comparators and vision systems. Piece part designs for mechanisms have started to include precision features on the face of parts that must be viewed using a reflected image rather than a profile shadow. The VOC concept uses a computer generated overlay and a digital camera to measure features on a video screen. The advantage of this system is superior edge detection compared to traditional systems. No vinyl charts are procured or inspected. The part size and expensive fixtures are no longer a concern because of the range of the X-Y table of the Virtual Optical Comparator. Product redesigns require only changes to the CAD image overlays; new vinyl charts are not required. The inspection process is more ergonomic by allowing the operator to view the part sitting at a desk rather than standing over a 30 inch screen. The procurement cost for the VOC will be less than a traditional comparator with a much smaller footprint with less maintenance and energy requirements.

  18. Realidad Virtual: Potencial Educativo

    Directory of Open Access Journals (Sweden)

    Luz Santamaría Granados

    2013-08-01

    Full Text Available El grupo GIBRANT centró sus esfuerzos en la investigación de realidad virtual, al experimentar en el uso de herramientas del consorcio Web3D (VRML y X3D, para el diseño y modelamiento de mundos virtuales en 3D, así pudo evidenciar el trabajo de estudiantes y docentes en el proyecto USTA en 3D; como tambien en algunas prácticas de formación en colegios de educación media, que involucran el uso de TIC, en el desarrollo de competencias de ubicación espacial, trigonométrica y rotación de objetos; y la construcción de escenaios que afianzan el proceso de enseñanza - aprendizaje en cuanquier área del saber. Este articulo quiere hacer ver la facilidad y la potencialidad de las MTIC e invita a la comunidad de educacion básica y media a apropiarse de estas tecnologías para su propio beneficio.

  19. Curating Virtual Data Collections

    Science.gov (United States)

    Lynnes, C.; Ramapriyan, H.; Leon, A.; Tsontos, V. M.; Liu, Z.; Shie, C. L.

    2015-12-01

    NASA's Earth Observing System Data and Information System (EOSDIS) contains a rich set of datasets and related services throughout its many elements. As a result, locating all the EOSDIS data and related resources relevant to particular science theme can be daunting. This is largely because EOSDIS data's organizing principle is affected more by the way they are produced than around the expected end use.Virtual collections oriented around science themes can overcome this by presenting collections of data and related resources that are organized around the user's interest, not around the way the data were produced. Science themes can be: Specific applications (uses) of the data, e.g., landslide prediction Geophysical events (e.g., Hurricane Sandy) A specific science research problem Virtual collections consist of annotated web addresses (URLs) that point to data and related resource addresses, thus avoiding the need to copy all of the relevant data to a single place. These URL addresses can be consumed by a variety of clients, ranging from basic URL downloaders (wget, curl) and web browsers to sophisticated data analysis programs such as the Integrated Data Viewer. Eligible resources include anything accessible via URL: data files: data file URLs data subsets: OPeNDAP, webification or Web Coverage Service URLs data visualizations: Web Map Service data search results: OpenSearch Atom response custom analysis workflows: e.g., Giovanni analysis URL

  20. Virtual reality in telemedicine.

    Science.gov (United States)

    Riva, G; Gamberini, L

    2000-01-01

    Virtual reality (VR) can be considered as the leading edge of a general evolution of present communication interfaces involving the television, computer, and telephone. The main characteristic of this evolution is the full immersion of the human sensorimotor channels into a vivid and global communication experience. Because telemedicine principally focuses on transmitting medical information, VR has the potential to enhance this function. Particularly, VR can be used in telemedicine as an advanced communication interface, which enables a more intuitive mode of interacting with information, and as a flexible environment that enhances the feeling of physical presence during the interaction. In this article, the state of the art in VR-based telemedicine applications is described. This technology is now used in remote or augmented surgery as well as surgical training, which are critically dependent on eye-hand coordination. Recently, however, different researchers have tried to use virtual environments in medical visualization and for assessment and rehabilitation in neuropsychology. This article also discusses technological, ergonomical, and human factor issues, and specific guidelines are presented for expanding the use of VR in telemedicine.

  1. When Virtual Worlds Expand

    Science.gov (United States)

    Bainbridge, William Sims

    The future of a virtual world depends on whether it can grow in subjective size, cultural content, and numbers of human participants. In one form of growth, exemplified by Second Life, the scope of a world increases gradually as new sponsors pay for new territory and inhabitants create content. A very different form of growth is sudden expansion, as when World of Warcraft (WoW) added entire new continents in its Burning Crusade and Lich King expansions (Lummis and Kern 2006, 2008; Corneliussen and Rettberg 2008; Sims et al. 2008). Well-established gamelike worlds have often undergone many expansions. Both the pioneer science fiction game Anarchy Online, which was launched in 2001, and Star Wars Galaxies dating from 2003, have had three, and EVE Online also from 2003 has had nine, although smaller ones. This chapter reports research on WoW's 2008 Lich King expansion, using both quantitative and qualitative methods, in order to develop theoretical ideas of the implications of expansion for virtual worlds.

  2. Virtual anthropology meets biomechanics.

    Science.gov (United States)

    Weber, Gerhard W; Bookstein, Fred L; Strait, David S

    2011-05-17

    A meeting in Vienna in October 2010 brought together researchers using Virtual Anthropology (VA) and Finite Element Analysis (FEA) in order to explore the benefits and problems facing a collaboration between the two fields. FEA is used to test mechanical hypotheses in functional anatomy and VA complements and augments this process by virtue of its tools for acquiring data, for segmenting and preparing virtual specimens, and for generating reconstructions and artificial forms. This represents a critical methodological advance because geometry is one of the crucial inputs of FEA and is often the variable of interest in functional anatomy. However, we currently lack tools that quantitatively relate differences in geometry to differences in stress and strain, or that evaluate the impact on FEA of variation within and between biological samples. Thus, when comparing models of different geometry, we do not currently obtain sufficiently informative answers to questions such as "How different are these models, and in what manner are they different? Are they different in some anatomical regions but not others?" New methodologies must be developed in order to maximize the potential of FEA to address questions in comparative and evolutionary biology. In this paper we review these and other important issues that were raised during our Vienna meeting. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Sonic intelligence as a virtual therapeutic environment.

    Science.gov (United States)

    Tarnanas, Ioannis; Adam, Dimitrios

    2003-06-01

    %). In Phase II, the difference again favored the VRSA group against the other two. These results indicate that a virtual collaborative environment seems to be a consistent coping environment, tapping two classes of stress: (a) aversive or ambiguous situations, and (b) loss or failure situations in relation to the stress inoculation theory. In terms of coping behaviors, a distinction is made between self-directed and environment-directed strategies. A great advantage of the virtual collaborative environment with the behaviorally enhanced sound-kinetic avatar is the consideration of team coping intentions in different stages. Even if the aim is to tap transactional processes in real-life situations, it might be better to conduct research using a sound-kinetic avatar based collaborative environment than a virtual first-person perspective scenario alone. The VE consisted of two dual-processor PC systems, a video splitter, a digital camera and two stereoscopic CRT displays. The system was programmed in C++ and VRScape Immersive Cluster from VRCO, which created an artificial environment that encodes the user's motion from a video camera, targeted at the face of the users and physiological sensors attached to the body.

  4. Wireless sensor platform

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Pooran C.; Killough, Stephen M.; Kuruganti, Phani Teja

    2017-08-08

    A wireless sensor platform and methods of manufacture are provided. The platform involves providing a plurality of wireless sensors, where each of the sensors is fabricated on flexible substrates using printing techniques and low temperature curing. Each of the sensors can include planar sensor elements and planar antennas defined using the printing and curing. Further, each of the sensors can include a communications system configured to encode the data from the sensors into a spread spectrum code sequence that is transmitted to a central computer(s) for use in monitoring an area associated with the sensors.

  5. Virtual Technologies Trends in Education

    Science.gov (United States)

    Martín-Gutiérrez, Jorge; Mora, Carlos Efrén; Añorbe-Díaz, Beatriz; González-Marrero, Antonio

    2017-01-01

    Virtual reality captures people's attention. This technology has been applied in many sectors such as medicine, industry, education, video games, or tourism. Perhaps its biggest area of interest has been leisure and entertainment. Regardless the sector, the introduction of virtual or augmented reality had several constraints: it was expensive, it…

  6. Virtual Learning: Possibilities and Realization

    Science.gov (United States)

    Kerimbayev, Nurassyl

    2016-01-01

    In the article it was important to consider two basic moments i.e., impact mode of using virtual environment at training process within one faculty of the University, directly at training quality and what outcomes can be reached therewith. The work significance consists of studying the virtual environment effect instead of traditional educational…

  7. Has your greenhouse gone virtual?

    Science.gov (United States)

    Virtual Grower is a free decision-support software program available from USDA-ARS that allows growers to build a virtual greenhouse. It was initially designed to help greenhouse growers estimate heating costs and conduct simple simulations to figure out where heat savings could be achieved. Featu...

  8. Geographical Information in Virtual Environments

    NARCIS (Netherlands)

    Loo, J. van; Lawick van Pabst, J. van

    1998-01-01

    We studied the combination of a Geographical Information System (GIS) and a Virtual Environment (VE). The goal was to establish a bi-directional link between a GIS and a virtual environment. The first step was to combine three types of data to build the 3D world and store it into the GIS: a digital

  9. Virtual Teams and Knowledge Communication

    DEFF Research Database (Denmark)

    Lehtonen, Miikka; Kampf, Constance Elizabeth

    2014-01-01

    How does culture affect virtual teams and the knowledge communication processes in which they engage? As virtual spaces are increasingly used to support teams and establish collaboration in cross-cultural projects, the notion of cross-cultural communication can be understood as shifting from...

  10. Training Rowing with Virtual Environments

    OpenAIRE

    Gopher Daniel; Korman Maria; Hoffmann Charles; Varlet Manuel; Marin Ludovic; Bardy Benoît; Filippeschi Alessandro; Ruffaldi Emanuele; Bergamasco Massimo

    2011-01-01

    This paper presents the results of the design, implementation and evaluation of a platform for rowing training in Virtual Reality called SPRINT. The paper discusses how various aspects of the rowing skill can be analyzed and trained over a single common methodology and system platform. The result is a vision for new directions in the domain of sport training with Virtual Reality.

  11. Tactile displays in Virtual Environments

    NARCIS (Netherlands)

    Erp, J.B.F. van

    2001-01-01

    Virtual Reality (VR) technology allows the user to perceive and experience sensory contact with a nonphysical world. A complete Virtual Environment (VE) will provide this contact in all sensory modalities. However, even state-off-the-art VEs are often restricted to the visual modality only. The use

  12. The Virtual Intercultural Team Tool

    Science.gov (United States)

    Rus, Calin

    2010-01-01

    This article describes the Virtual Intercultural Team Tool (VITT) and discusses its processes and benefits. VIIT is a virtual platform designed with the aim of assisting European project teams to improve intercultural communication and build on their cultural diversity for effective implementation of their projects. It is a process-focused tool,…

  13. The metaphors of virtual worlds

    DEFF Research Database (Denmark)

    Reinhard, CarrieLynn D.

    The analysis of recollections of experiencing two types of virtual worlds where the recollections were in the form of metaphors.......The analysis of recollections of experiencing two types of virtual worlds where the recollections were in the form of metaphors....

  14. What is a virtual link?

    OpenAIRE

    Kuperberg, Greg

    2002-01-01

    Several authors have recently studied virtual knots and links because they admit invariants arising from R-matrices. We prove that every virtual link is uniquely represented by a link L in S X I, a thickened, compact, oriented surface S, such that the link complement (S X I) - L has no essential vertical cylinder.

  15. Virtual leadership in nursing education.

    Science.gov (United States)

    Levesque, Pamela

    2012-01-01

    The transition to online education with faculty teaching at a distance has created "virtual departments" of nursing that necessitates a new way of leading. The author discusses leadership theory and team-building methods to support leaders engaged in virtual departments of nursing.

  16. Developing Trust in Virtual Teams

    Science.gov (United States)

    Germain, Marie-Line

    2011-01-01

    Rapid globalization, advances in technology, flatter organizational structures, synergistic cooperation among firms, and a shift to knowledge work environments have led to the increasing use of virtual teams in organizations. Selecting, training, and socializing employees in virtual teamwork has therefore become an important human resource…

  17. Virtual Enterprise: Transforming Entrepreneurship Education

    Science.gov (United States)

    Borgese, Anthony

    2011-01-01

    Entrepreneurship education is ripe for utilizing experiential learning methods. Experiential methods are best learned when there is constant immersion into the subject matter. One such transformative learning methodology is Virtual Enterprise (VE). Virtual Enterprise is a multi-faceted, experiential learning methodology disseminated by the City…

  18. Virtual Reality, Combat, and Communication.

    Science.gov (United States)

    Thrush, Emily Austin; Bodary, Michael

    2000-01-01

    Presents a brief examination of the evolution of virtual reality devices that illustrates how the development of this new medium is influenced by emerging technologies and by marketing pressures. Notes that understanding these influences may help prepare for the role of technical communicators in building virtual reality applications for education…

  19. A Virtual History of Mauritius

    African Journals Online (AJOL)

    Nafiisah

    Abstract. Mauritius has a lot of cultural heritage sites that, until recently, have escaped our notice. It is only recently that ... presented. Keywords: Virtual Heritage, Virtual Reality, Archaeology, Mauritius. * To whom .... with better texturing (and bump mapping the wall), a skybox and some smart avatars we should have a very ...

  20. Virtual Reality and Special Needs

    Science.gov (United States)

    Jeffs, Tara L.

    2009-01-01

    The use of virtual environments for special needs is as diverse as the field of Special Education itself and the individuals it serves. Individuals with special needs often face challenges with attention, language, spatial abilities, memory, higher reasoning and knowledge acquisition. Research in the use of Virtual Learning Environments (VLE)…

  1. The Geography of Virtual Questioning

    Science.gov (United States)

    Mon, Lorri; Bishop, Bradley Wade; McClure, Charles R.; McGilvray, Jessica; Most, Linda; Milas, Theodore Patrick; Snead, John T.

    2009-01-01

    This article explores the geography of virtual questioning by using geographic information systems to study activity within the Florida Electronic Library "Ask a Librarian" collaborative chat service. Researchers mapped participating libraries throughout the state of Florida that served as virtual "entry portals" for users as…

  2. Enhancing Spiritualism in Virtual World

    Science.gov (United States)

    Dangwal, Kiran Lata; Singh, Shireesh Pal

    2012-01-01

    Spiritualism is one word which puts man on the highest plinth of life. Spirituality is the way we find meaning, hope, comfort and inner peace in life. Spirituality in the virtual World is generally known as Virtual Spirituality. A goldmine of wisdom from all kinds of religious and spiritual philosophies, traditions and practices can be found in…

  3. Gamification and Visualization of Sensor Data Analysis in Research Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Stone, Jackson A [ORNL; Sanyal, Jibonananda [ORNL; Castello, Charles C [ORNL; New, Joshua Ryan [ORNL

    2015-01-01

    The use of video game elements in non-gaming systems, or gamification , has potential value in transforming data analysis. Our study focused on creating a web-based videogame that models two physical test buildings, each of which contains hundreds of sensors. After the application renders the models, the player can walk through the environments and interact with the virtual representations of the sensors inside. Rather than trudging through a database with textual commands and screens full of data, the user can (virtually) walk up to a sensor and view its data graphically. But these features only scratch the surface of what is possible using our new gamification approach. We anticipate being able to show that recent progress in game design techniques and capacities can contribute to the field of analysis through gamification. The net result could be more stimulating, intuitive, user-friendly interfaces, as well as potentially more informative and insightful applications.

  4. Wavenumber-frequency Spectra of Pressure Fluctuations Measured via Fast Response Pressure Sensitive Paint

    Science.gov (United States)

    Panda, J.; Roozeboom, N. H.; Ross, J. C.

    2016-01-01

    The recent advancement in fast-response Pressure-Sensitive Paint (PSP) allows time-resolved measurements of unsteady pressure fluctuations from a dense grid of spatial points on a wind tunnel model. This capability allows for direct calculations of the wavenumber-frequency (k-?) spectrum of pressure fluctuations. Such data, useful for the vibro-acoustics analysis of aerospace vehicles, are difficult to obtain otherwise. For the present work, time histories of pressure fluctuations on a flat plate subjected to vortex shedding from a rectangular bluff-body were measured using PSP. The light intensity levels in the photographic images were then converted to instantaneous pressure histories by applying calibration constants, which were calculated from a few dynamic pressure sensors placed at selective points on the plate. Fourier transform of the time-histories from a large number of spatial points provided k-? spectra for pressure fluctuations. The data provides first glimpse into the possibility of creating detailed forcing functions for vibro-acoustics analysis of aerospace vehicles, albeit for a limited frequency range.

  5. Design of a Lightweight, Cost Effective Thimble-Like Sensor for Haptic Applications Based on Contact Force Sensors

    Directory of Open Access Journals (Sweden)

    Ignacio Galiana

    2011-12-01

    Full Text Available This paper describes the design and calibration of a thimble that measures the forces applied by a user during manipulation of virtual and real objects. Haptic devices benefit from force measurement capabilities at their end-point. However, the heavy weight and cost of force sensors prevent their widespread incorporation in these applications. The design of a lightweight, user-adaptable, and cost-effective thimble with four contact force sensors is described in this paper. The sensors are calibrated before being placed in the thimble to provide normal and tangential forces. Normal forces are exerted directly by the fingertip and thus can be properly measured. Tangential forces are estimated by sensors strategically placed in the thimble sides. Two applications are provided in order to facilitate an evaluation of sensorized thimble performance. These applications focus on: (i force signal edge detection, which determines task segmentation of virtual object manipulation, and (ii the development of complex object manipulation models, wherein the mechanical features of a real object are obtained and these features are then reproduced for training by means of virtual object manipulation.

  6. Formal modeling of virtual machines

    Science.gov (United States)

    Cremers, A. B.; Hibbard, T. N.

    1978-01-01

    Systematic software design can be based on the development of a 'hierarchy of virtual machines', each representing a 'level of abstraction' of the design process. The reported investigation presents the concept of 'data space' as a formal model for virtual machines. The presented model of a data space combines the notions of data type and mathematical machine to express the close interaction between data and control structures which takes place in a virtual machine. One of the main objectives of the investigation is to show that control-independent data type implementation is only of limited usefulness as an isolated tool of program development, and that the representation of data is generally dictated by the control context of a virtual machine. As a second objective, a better understanding is to be developed of virtual machine state structures than was heretofore provided by the view of the state space as a Cartesian product.

  7. Diagnostic accuracy in virtual dermatopathology

    DEFF Research Database (Denmark)

    Mooney, E.; Kempf, W.; Jemec, G.B.E.

    2012-01-01

    Background Virtual microscopy is used for teaching medical students and residents and for in-training and certification examinations in the United States. However, no existing studies compare diagnostic accuracy using virtual slides and photomicrographs. The objective of this study was to compare...... diagnostic accuracy of dermatopathologists and pathologists using photomicrographs vs. digitized images, through a self-assessment examination, and to elucidate assessment of virtual dermatopathology. Methods Forty-five dermatopathologists and pathologists received a randomized combination of 15 virtual...... slides and photomicrographs with corresponding clinical photographs and information in a self-assessment examination format. Descriptive data analysis and comparison of groups were performed using a chi-square test. Results Diagnostic accuracy in dermatopathology using virtual dermatopathology...

  8. Modelling Virtual Environments for Geovisualization

    DEFF Research Database (Denmark)

    Bodum, Lars

    2005-01-01

    The use of virtual environments in geovisualization has become a major topic within the last few years. The main reason for this interest in the growing use of 3D models and visual realizations in a wide range of applications concerned with the geographic element of information. The implementation...... and use of virtual environments has developed form being a rather sophisticated type of visualization that demanded extreme computer resources to become an integral part of the software on every desktop computer. This chapter addresses both philosophical and technical issues regarding the modelling...... of virtual environments. It specifically focuses on different representational aspects to be taken into consideration when a virtual environment is created. These aspects are data modelling, 3D modelling and level-of-detail. A range of different approaches can be taken to visualize a virtual environment...

  9. Virtual Reality Simulation of the International Space Welding Experiment

    Science.gov (United States)

    Phillips, James A.

    1996-01-01

    Virtual Reality (VR) is a set of breakthrough technologies that allow a human being to enter and fully experience a 3-dimensional, computer simulated environment. A true virtual reality experience meets three criteria: (1) It involves 3-dimensional computer graphics; (2) It includes real-time feedback and response to user actions; and (3) It must provide a sense of immersion. Good examples of a virtual reality simulator are the flight simulators used by all branches of the military to train pilots for combat in high performance jet fighters. The fidelity of such simulators is extremely high -- but so is the price tag, typically millions of dollars. Virtual reality teaching and training methods are manifestly effective, and we have therefore implemented a VR trainer for the International Space Welding Experiment. My role in the development of the ISWE trainer consisted of the following: (1) created texture-mapped models of the ISWE's rotating sample drum, technology block, tool stowage assembly, sliding foot restraint, and control panel; (2) developed C code for control panel button selection and rotation of the sample drum; (3) In collaboration with Tim Clark (Antares Virtual Reality Systems), developed a serial interface box for the PC and the SGI Indigo so that external control devices, similar to ones actually used on the ISWE, could be used to control virtual objects in the ISWE simulation; (4) In collaboration with Peter Wang (SFFP) and Mark Blasingame (Boeing), established the interference characteristics of the VIM 1000 head-mounted-display and tested software filters to correct the problem; (5) In collaboration with Peter Wang and Mark Blasingame, established software and procedures for interfacing the VPL DataGlove and the Polhemus 6DOF position sensors to the SGI Indigo serial ports. The majority of the ISWE modeling effort was conducted on a PC-based VR Workstation, described below.

  10. Gas Sensors: A Review

    Directory of Open Access Journals (Sweden)

    Zainab Yunusa

    2014-04-01

    Full Text Available In this paper a review of different technologies for gas sensors is presented. The different types of gas sensors technologies including catalytic gas sensor, electrochemical gas sensors, thermal conductivity gas sensor, optical gas sensor and acoustic gas sensor are discussed together with their principle of operation. The Surface Acoustic Wave Gas Sensor technology is discussed in greater detail. The advantages and disadvantages of each sensor technology are also highlighted. All these technologies have been used for several decades for the development of highly sensitive and responsive gas sensors for the detection of flammable and hazardous gases. However, for improved sensitivity and selectivity for these sensors, future trends and outlook for researchers are suggested in the conclusion of this article.

  11. Virtual hand: a 3D tactile interface to virtual environments

    Science.gov (United States)

    Rogowitz, Bernice E.; Borrel, Paul

    2008-02-01

    We introduce a novel system that allows users to experience the sensation of touch in a computer graphics environment. In this system, the user places his/her hand on an array of pins, which is moved about space on a 6 degree-of-freedom robot arm. The surface of the pins defines a surface in the virtual world. This "virtual hand" can move about the virtual world. When the virtual hand encounters an object in the virtual world, the heights of the pins are adjusted so that they represent the object's shape, surface, and texture. A control system integrates pin and robot arm motions to transmit information about objects in the computer graphics world to the user. It also allows the user to edit, change and move the virtual objects, shapes and textures. This system provides a general framework for touching, manipulating, and modifying objects in a 3-D computer graphics environment, which may be useful in a wide range of applications, including computer games, computer aided design systems, and immersive virtual worlds.

  12. Very High Frequency Monitoring System for Engine Gearbox and Generator Health Management (Postprint)

    National Research Council Canada - National Science Library

    Watson, Matthew J; Byington, Carl S; Behbahani, Alireza

    2007-01-01

    ...) vibration monitoring system that integrates various vibro-acoustic data with intelligent feature extraction and fault isolation algorithms to effectively assess engine gearbox and generator health...

  13. A modular optical sensor

    Science.gov (United States)

    Conklin, John Albert

    This dissertation presents the design of a modular, fiber-optic sensor and the results obtained from testing the modular sensor. The modular fiber-optic sensor is constructed in such manner that the sensor diaphragm can be replaced with different configurations to detect numerous physical phenomena. Additionally, different fiber-optic detection systems can be attached to the sensor. Initially, the modular sensor was developed to be used by university of students to investigate realistic optical sensors and detection systems to prepare for advance studies of micro-optical mechanical systems (MOMS). The design accomplishes this by doing two things. First, the design significantly lowers the costs associated with studying optical sensors by modularizing the sensor design. Second, the sensor broadens the number of physical phenomena that students can apply optical sensing techniques to in a fiber optics sensor course. The dissertation is divided into seven chapters covering the historical development of fiber-optic sensors, a theoretical overview of fiber-optic sensors, the design, fabrication, and the testing of the modular sensor developed in the course of this work. Chapter 1 discusses, in detail, how this dissertation is organized and states the purpose of the dissertation. Chapter 2 presents an historical overview of the development of optical fibers, optical pressure sensors, and fibers, optical pressure sensors, and optical microphones. Chapter 3 reviews the theory of multi-fiber optic detection systems, optical microphones, and pressure sensors. Chapter 4 presents the design details of the modular, optical sensor. Chapter 5 delves into how the modular sensor is fabricated and how the detection systems are constructed. Chapter 6 presents the data collected from the microphone and pressure sensor configurations of the modular sensor. Finally, Chapter 7 discusses the data collected and draws conclusions about the design based on the data collected. Chapter 7 also

  14. VIRTUAL REALITY HYPNOSIS.

    Science.gov (United States)

    Askay, Shelley Wiechman; Patterson, David R; Sharar, Sam R

    2009-03-01

    Scientific evidence for the viability of hypnosis as a treatment for pain has flourished over the past two decades (Rainville, Duncan, Price, Carrier and Bushnell, 1997; Montgomery, DuHamel and Redd, 2000; Lang and Rosen, 2002; Patterson and Jensen, 2003). However its widespread use has been limited by factors such as the advanced expertise, time and effort required by clinicians to provide hypnosis, and the cognitive effort required by patients to engage in hypnosis.The theory in developing virtual reality hypnosis was to apply three-dimensional, immersive, virtual reality technology to guide the patient through the same steps used when hypnosis is induced through an interpersonal process. Virtual reality replaces many of the stimuli that the patients have to struggle to imagine via verbal cueing from the therapist. The purpose of this paper is to explore how virtual reality may be useful in delivering hypnosis, and to summarize the scientific literature to date. We will also explore various theoretical and methodological issues that can guide future research.In spite of the encouraging scientific and clinical findings, hypnosis for analgesia is not universally used in medical centres. One reason for the slow acceptance is the extensive provider training required in order for hypnosis to be an effective pain management modality. Training in hypnosis is not commonly offered in medical schools or even psychology graduate curricula. Another reason is that hypnosis requires far more time and effort to administer than an analgesic pill or injection. Hypnosis requires training, skill and patience to deliver in medical centres that are often fast-paced and highly demanding of clinician time. Finally, the attention and cognitive effort required for hypnosis may be more than patients in an acute care setting, who may be under the influence of opiates and benzodiazepines, are able to impart. It is a challenge to make hypnosis a standard part of care in this environment

  15. Virtual autopsy in hanging.

    Science.gov (United States)

    Polacco, Matteo; D'Alessio, Pasquale; Ausania, Francesco; Zobel, Bruno; Pascali, Vincenzo Lorenzo; d'Aloja, Ernesto; Miscusi, Massimo; De-Giorgio, Fabio

    2013-06-01

    The aim of the study was to compare postmortem computed tomographic (CT) imaging findings from a case of hanging with the autopsy findings. The CT showed a good match with autopsy findings especially for bone, soft tissue, and spinal injuries. The CT images of the injuries of the neck obtained by CT scan clearly showed the ligature mark, the hemorrhagic suffusion in the soft tissue (thickening of derma) and in the muscles (sternocleidomastoid) of the neck. Furthermore, CT 3-dimensional reconstruction showed brain edema, fracture of the left posterior horn of the hyoid bone, and a grade 1 retrolisthesis of C5 on C6. This last finding was not detected by autopsy because of the anterior approach that is frequently used in necropsy technique. Nevertheless, the CT virtual autopsy did not show vascular findings (like Amussat mark) because a barium mixture was not injected in the body.

  16. Designing Virtual Worlds

    DEFF Research Database (Denmark)

    Gürsimsek, Remzi Ates

    2014-01-01

    The online social platforms known as virtual worlds present their users various affordances for avatar based co-presence, social interaction and provide tools for collaborative content creation, including objects, textures and animations. The users of these worlds navigate their avatars as personal...... world known as Second Life by the collaborative efforts of its so-called residents. The social semiotic perspective is used to develop a multimodal analytical framework and to analyze the co-creation of meaning potentials by various social actors who use the available semiotic resources as mediational...... means. The findings show that co-design and co-creation practices do not only depend on various actors and their mediated interactions, but also on a variety of tools, practices and resources that digital media platforms provide. Moreover, the multimodal analysis of these places demonstrates how...

  17. Virtual Acts of Balance!

    DEFF Research Database (Denmark)

    Madsen, Anders Koed

    2013-01-01

    This paper presents an analysis of official documents and white papers pertaining to the two web-portals The Policy Grid Project and FEED that are launched by the UK and the EU respectively. The aim of the portals is to filter and synthesize information relevant for policy discussions and thereby...... Construction of Technology' and it shows how the framing of the portals and the concrete digital choices taken in relation to the infrastructure are influenced by the social intentions of relevant social groups as well as by the technical limitations on computers abilities to process semantic data....... It is especially emphasized how technical web-ontologies implicitly carries with them deeper philosophical ontologies about phanomena such as 'politic', 'scientific intentionality' and 'freedom'. The compromise between these technical influences and the social intentions is described as a 'virtual act of balance...

  18. Virtual reality in posturography.

    Science.gov (United States)

    Tossavainen, Timo; Toppila, Esko; Pyykkö, Ilmari; Forsman, Pia M; Juhola, Martti; Starck, Jukka

    2006-04-01

    Balance dysfunctions are common, especially among elderly people. Present methods for the diagnosis and evaluation of severity of dysfuntion have limited value. We present a system that makes it easy to implement different visual and mechanical perturbations for clinical investigations of balance and visual-vestibular interaction. The system combines virtual reality visual stimulation with force platform posturography on a moving platform. We evaluate our contruction's utility in a classification task between 33 healthy controls and 77 patients with Ménière's disease, using a series of tests with different visual and mechanical stimuli. Responses of patients and controls differ significantly in parameters computed from stabilograms. We also show that the series of tests achieves a classification accuracy slightly over 80% between controls and patients.

  19. Are Virtual Classrooms Colorblind?

    Science.gov (United States)

    Killion, Cheryl M; Gallagher-Lepak, Susan; Reilly, Janet

    2015-01-01

    E-learning, increasingly employed in nursing education, has been embraced as a means to enhance options for all students, particularly those with limited educational opportunities. Although a desire to increase access for underserved students is often cited, disparities in availability, usage, and quality of e-learning persist among diverse households and student populations when compared to the general population. In this article, these issues will be examined along with reflection on the extent to which culture has been integrated into on-line design and instruction. Historical and cultural aspects, circumscribing virtual classrooms, are discussed using African Americans as an exemplar. The imperative to harness the democratizing potential of this educational format is underscored. In this article, culture will be examined in light of the significant growth in on-line nursing education over the past several decades. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Geomatics and virtual tourism

    Directory of Open Access Journals (Sweden)

    Valeria Minucciani

    2013-09-01

    Full Text Available The most recent technological revolution, concerning web and “ICT”, not only changed individual and collective behaviors, but also allowed experiences no possible before: a real time communication, regardless of the distances; an extended access to disjointed data and sources; the shift in different realities – missing or entirely imaginary. Nowadays, we can think about a new concept of museum, much more inclusive than “objects container”: now the museum involves entire countries, entire ecosystems, entire regions. We can speak of “museum outside of the museum”, to extend museum “storytelling” to a regional scale, beyond the walls of the traditional museum. On a regional scale experiments entirely convincing have not yet been carried out, but from this point of view cultural lands can be visited as great open air museums, to find objects, artworks or signs: the whole land is a “collection” to be preserved, to be presented and to be interpreted. Thus the visit allows to elicit outstanding objects, to read into landscapes with different filters. Both the physical and virtual visit seem to be a “tour” (Minucciani and Garnero, 2013. To create a virtual tourism prototypal station, we need several and unconventional geometrical data (shared geographic databases, DTMs, digital orthoimages and angle shots, modeling with spherical cameras, ..., thematic data (related to cultural content and no conventional input units to move and to observe how and where the observer prefers. Authors report here their experience to carry out a prototypal station, able to relate geomatics references to cultural content and to offer a whole experience, involving users also from the sensory point of view. That’s nowadays a specific purpose of new technologies applied to cultural heritage.

  1. Virtual reality and anthropology

    Energy Technology Data Exchange (ETDEWEB)

    Recheis, Wolfgang E-mail: wolfgang.recheis@uibk.ac.at; Weber, Gerhard W.; Schaefer, Katrin; Knapp, Rudolf; Seidler, Horst; Zur Nedden, Dieter

    1999-08-01

    Since the discovery of the Tyrolean Iceman in 1991 advanced imaging and post processing techniques were successfully applied in anthropology. Specific techniques include spiral computed tomography and 3-dimensional reconstructions including stereolithographic and fused deposition modeling of volume data sets. The Iceman's skull was the first to be reproduced using stereolithography, before this method was successfully applied in preoperative planning. With the advent of high-end graphics workstations and biomedical image processing software packages, 3-dimensional reconstructions were established as a routine tool for analyzing volume data sets. These techniques opened totally new insights in the field of physical anthropology. Computed tomography became the ideal research tool to access the internal structures of various precious fossils without damaging or even touching them. Many of the most precious specimens from the species Autralopithecus (1.8-3.5 Myears), Homo heidelbergensis (200-600 kyears) or Homo neanderthalensis (40-100 kyears) were scanned during the last 5 years. Often the fossils are filled with a stone matrix or other materials. During the postprocessing routines highly advanced algorithms were used to remove virtually these incrustations. Thus it was possible to visualize the morphological structures that lie beneath the matrix. Some specimens were partially destroyed, so the missing parts were reconstructed on computer screen in order to get estimations of the brain volume and endocranial morphology, both major fields of interest in physical anthropology. Moreover the computerized form of the data allows new descriptions of morphologic structures by the means of 'geometric morphometrics'. Some of the results may change aspects and interpretations in human evolution. The introduction of new imaging and post processing techniques created a new field of research: Virtual Anthropology.

  2. Tracking Virtual Trajectories

    Science.gov (United States)

    Stone, Leland S.; Beutter, Brent R.; Lorenceau, Jean D.; Null, Cynthia H. (Technical Monitor)

    1996-01-01

    Current models of smooth pursuit eye movements assume that it is largely driven by retinal image motion. We tested this hypothesis by measuring pursuit of elliptical motion (3.2s, 0.9 Hz, 1.4 deg x 1.6 deg, 4 randomly interleaved phases) of either a small spot ("real" motion) or of a line-figure diamond viewed through apertures such that only the motion of four isolated oblique line segments was visible ("virtual" motion). Each segment moved sinusoidally along a linear trajectory yet subjects perceived a diamond moving along an elliptical path behind the aperture. We found, as expected, that real motion produced accurate tracking (N = 2) with mean gain (over horizontal and vertical) of 0.9, mean phase of -6 deg (lag), mean relative phase (H vs V) of 90 +/- 8 deg (RMS error). Virtual motion behind an X-shaped aperture (N= 4 with one naive) yielded a mean gain of 0.7, mean phase of -11 deg, mean relative phase of 87 +/- 15 deg. We also measured pursuit with the X-shaped aperture using a higher segment luminance which prevents the segments from being grouped into a coherently moving diamond while keeping the motion otherwise identical. In this incoherent case, the same four subjects no longer showed consistent elliptical tracking (RMS error in relative phase rose to 60 deg) suggesting that perceptual coherence is critical. Furthermore, to rule out tracking of the centroid, we also used vertical apertures so that all segment motion was vertical (N = 3). This stimulus still produced elliptical tracking (mean relative phase of 84 +/- 19 deg), albeit with a lower gain (0.6). These data show that humans can track moving objects reasonably accurately even when the trajectory can only be derived by spatial integration of motion signals. Models that merely seek to minimize retinal or local stimulus motion cannot explain these results.

  3. The Virtual Environment for Rapid Prototyping of the Intelligent Environment

    Directory of Open Access Journals (Sweden)

    Yannick Francillette

    2017-11-01

    Full Text Available Advances in domains such as sensor networks and electronic and ambient intelligence have allowed us to create intelligent environments (IEs. However, research in IE is being held back by the fact that researchers face major difficulties, such as a lack of resources for their experiments. Indeed, they cannot easily build IEs to evaluate their approaches. This is mainly because of economic and logistical issues. In this paper, we propose a simulator to build virtual IEs. Simulators are a good alternative to physical IEs because they are inexpensive, and experiments can be conducted easily. Our simulator is open source and it provides users with a set of virtual sensors that simulates the behavior of real sensors. This simulator gives the user the capacity to build their own environment, providing a model to edit inhabitants’ behavior and an interactive mode. In this mode, the user can directly act upon IE objects. This simulator gathers data generated by the interactions in order to produce datasets. These datasets can be used by scientists to evaluate several approaches in IEs.

  4. The Virtual Environment for Rapid Prototyping of the Intelligent Environment.

    Science.gov (United States)

    Francillette, Yannick; Boucher, Eric; Bouzouane, Abdenour; Gaboury, Sébastien

    2017-11-07

    Advances in domains such as sensor networks and electronic and ambient intelligence have allowed us to create intelligent environments (IEs). However, research in IE is being held back by the fact that researchers face major difficulties, such as a lack of resources for their experiments. Indeed, they cannot easily build IEs to evaluate their approaches. This is mainly because of economic and logistical issues. In this paper, we propose a simulator to build virtual IEs. Simulators are a good alternative to physical IEs because they are inexpensive, and experiments can be conducted easily. Our simulator is open source and it provides users with a set of virtual sensors that simulates the behavior of real sensors. This simulator gives the user the capacity to build their own environment, providing a model to edit inhabitants' behavior and an interactive mode. In this mode, the user can directly act upon IE objects. This simulator gathers data generated by the interactions in order to produce datasets. These datasets can be used by scientists to evaluate several approaches in IEs.

  5. Intelligent virtual interfaces for telerobotics

    Science.gov (United States)

    Grinstein, Georges G.; Maybury, Mark T.; Mitchell, Richard B.

    1992-11-01

    One promise of telerobotics is the ability to interact in environments that are distant (e.g., deep sea or deep space), dangerous (e.g., nuclear, chemical, or biological environments), or inaccessible by humans for political or legal reasons. A key component to such interactions are sophisticated human-computer interfaces that can replicate sufficient information about a local environment to permit remote navigation and manipulation. This environment replication can, in part, be provided by technologies such as virtual reality. In addition, however, telerobotic interfaces may need to enhance human-machine interaction to assist users in task performance, for example, governing motion or manipulation controls to avoid obstacles or to restrict interaction with certain objects (e.g., avoiding contact with a live mine or a deep sea treasure). Thus, effective interactions within remote environments require intelligent virtual interfaces to telerobotic devices. In part to address this problem, MITRE is investigating virtual reality architectures that will enable enhanced interaction within virtual environments. Key components to intelligent virtual interfaces include spoken language processing, gesture recognition algorithms, and more generally, task recognition. In addition, these interfaces will eventually have to take into account properties of the user, the task, and discourse context to be more adaptive to the current situation at hand. While our work has not yet investigated the connection of virtual interfaces to external robotic devices, we have begun developing the key components for intelligent virtual interfaces for information and training systems.

  6. ABSTRACT MODELS FOR SYSTEM VIRTUALIZATION

    Directory of Open Access Journals (Sweden)

    M. G. Koveshnikov

    2015-05-01

    Full Text Available The paper is dedicated to issues of system objects securing (system files and user system or application configuration files against unauthorized access including denial of service attacks. We have suggested the method and developed abstract system virtualization models, which are used toresearch attack scenarios for different virtualization modes. Estimation for system tools virtualization technology effectiveness is given. Suggested technology is based on redirection of access requests to system objects shared among access subjects. Whole and partial system virtualization modes have been modeled. The difference between them is the following: in the whole virtualization mode all copies of access system objects are created whereon subjects’ requests are redirected including corresponding application objects;in the partial virtualization mode corresponding copies are created only for part of a system, for example, only system objects for applications. Alternative solutions effectiveness is valued relating to different attack scenarios. We consider proprietary and approved technical solution which implements system virtualization method for Microsoft Windows OS family. Administrative simplicity and capabilities of correspondingly designed system objects security tools are illustrated on this example. Practical significance of the suggested security method has been confirmed.

  7. Application of Virtual, Augmented, and Mixed Reality to Urology.

    Science.gov (United States)

    Hamacher, Alaric; Kim, Su Jin; Cho, Sung Tae; Pardeshi, Sunil; Lee, Seung Hyun; Eun, Sung-Jong; Whangbo, Taeg Keun

    2016-09-01

    Recent developments in virtual, augmented, and mixed reality have introduced a considerable number of new devices into the consumer market. This momentum is also affecting the medical and health care sector. Although many of the theoretical and practical foundations of virtual reality (VR) were already researched and experienced in the 1980s, the vastly improved features of displays, sensors, interactivity, and computing power currently available in devices offer a new field of applications to the medical sector and also to urology in particular. The purpose of this review article is to review the extent to which VR technology has already influenced certain aspects of medicine, the applications that are currently in use in urology, and the future development trends that could be expected.

  8. Application of Virtual, Augmented, and Mixed Reality to Urology

    Science.gov (United States)

    2016-01-01

    Recent developments in virtual, augmented, and mixed reality have introduced a considerable number of new devices into the consumer market. This momentum is also affecting the medical and health care sector. Although many of the theoretical and practical foundations of virtual reality (VR) were already researched and experienced in the 1980s, the vastly improved features of displays, sensors, interactivity, and computing power currently available in devices offer a new field of applications to the medical sector and also to urology in particular. The purpose of this review article is to review the extent to which VR technology has already influenced certain aspects of medicine, the applications that are currently in use in urology, and the future development trends that could be expected. PMID:27706017

  9. Biosimmer: A Virtual Reality Simulator for Training First Responders in a BW Scenario

    Energy Technology Data Exchange (ETDEWEB)

    Shawver, D.M.; Sobel, A.L.; Stansfield, S.A.

    1998-11-11

    BioSimMER (Bioterrorism Simulated Medical Emergency Response) is a Virtual Reality-based mission rehearsal and training environment. BioSimMER employs contingency-oriented, multiple-path algorithms and MOESINIOPS focused on real-world operations. BioSimMER is network-based and immerses multiple trainees in a high resolution synthetic environment, including virtual casualties and instruments that they may interact with and manipulate. Trainees are represented as individuals by virtual human Avatars. The simulation consists of several components: virtual casualties dynamically manifest the symptoms of their injuries and respond to the intervention of the trainees. Agent transport analysis is used to simulate casualty exposures and to drive the responses of simulated sensors/detectors. The selected prototype scenario is representative of combined injuries anticipated in BW operations.

  10. EDITORIAL: Humidity sensors Humidity sensors

    Science.gov (United States)

    Regtien, Paul P. L.

    2012-01-01

    produced at relatively low cost. Therefore, they find wide use in lots of applications. However, the method requires a material that possesses some conflicting properties: stable and reproducible relations between air humidity, moisture uptake and a specific property (for instance the length of a hair, the electrical impedance of the material), fast absorption and desorption of the water vapour (to obtain a short response time), small hysteresis, wide range of relative humidity (RH) and temperature-independent output (only responsive to RH). For these reasons, much research is done and is still going on to find suitable materials that combine high performance and low price. In this special feature, three of the four papers report on absorption sensors, all with different focus. Aziz et al describe experiments with newly developed materials. The surface structure is extensively studied, in view of its ability to rapidly absorb water vapour and exhibit a reproducible change in the resistance and capacitance of the device. Sanchez et al employ optical fibres coated with a thin moisture-absorbing layer as a sensitive humidity sensor. They have studied various coating materials and investigated the possibility of using changes in optical properties of the fibre (here the lossy mode resonance) due to a change in humidity of the surrounding air. The third paper, by Weremczuk et al, focuses on a cheap fabrication method for absorption-based humidity sensors. The inkjet technology appears to be suitable for mass fabrication of such sensors, which is demonstrated by extensive measurements of the electrical properties (resistance and capacitance) of the absorbing layers. Moreover, they have developed a model that describes the relation between humidity and the electrical parameters of the moisture-sensitive layer. Despite intensive research, absorption sensors still do not meet the requirements for high accuracy applications. The dew-point temperature method is more appropriate

  11. Virtual agents in a simulated virtual training environment

    Science.gov (United States)

    Achorn, Brett; Badler, Norman L.

    1993-01-01

    A drawback to live-action training simulations is the need to gather a large group of participants in order to train a few individuals. One solution to this difficulty is the use of computer-controlled agents in a virtual training environment. This allows a human participant to be replaced by a virtual, or simulated, agent when only limited responses are needed. Each agent possesses a specified set of behaviors and is capable of limited autonomous action in response to its environment or the direction of a human trainee. The paper describes these agents in the context of a simulated hostage rescue training session, involving two human rescuers assisted by three virtual (computer-controlled) agents and opposed by three other virtual agents.

  12. Virtual reality for spherical images

    Science.gov (United States)

    Pilarczyk, Rafal; Skarbek, Władysław

    2017-08-01

    Paper presents virtual reality application framework and application concept for mobile devices. Framework uses Google Cardboard library for Android operating system. Framework allows to create virtual reality 360 video player using standard OpenGL ES rendering methods. Framework provides network methods in order to connect to web server as application resource provider. Resources are delivered using JSON response as result of HTTP requests. Web server also uses Socket.IO library for synchronous communication between application and server. Framework implements methods to create event driven process of rendering additional content based on video timestamp and virtual reality head point of view.

  13. VIRTUAL AND PHYSICAL ARCHITECTURAL ATMOSPHERE

    DEFF Research Database (Denmark)

    Hermund, Anders; Klint, Lars

    2016-01-01

    This study, of the similarities between the perception of architectural space experienced in physical space conditions and in Virtual Reality, intents to clarify to what extend subjective and objective attributes of architectural space can be conveyed through a direct use of Building Information...... Models in Virtual Reality. 60 test persons experienced a specific test space as either a physical or a virtual environment, while data from their experiences was collected through a quantitative/qualitative questionnaire. The overall conclusion, from this phase of the study, is that even a simple BIM...

  14. ACE Strategy with Virtual Channels

    Directory of Open Access Journals (Sweden)

    T. Tichy

    2008-12-01

    Full Text Available Cochlear implant is an electronic device, which can mediate hearing sensations to profoundly deaf people. Contemporary cochlear implants are sophisticated electronic devices; however, their performance could still be improved. This paper describes an experiment we made in that direction: additional 21 virtual channels were implemented by sequential stimulation of adjacent intracochlear electrodes, and the ACE strategy with virtual channels (ACEv, Advanced Combination Encoder strategy with virtual channels for the Nucleus® 24 Cochlear Implant System was created and verified in a clinical test with four patients.

  15. Leading a Virtual Intercultural Team. Implications for Virtual Team Leaders

    OpenAIRE

    Chutnik, Monika; Grzesik, Katarzyna

    2009-01-01

    Increasing number of companies operate in the setup of teams whose members are geographically scattered and have different cultural origins. They work through access to the same digital network and communicate by means of modern technology. Sometimes they are located in different time zones and have never met each other face to face. This is the age of a virtual team leader. Virtual leadership in intercultural groups requires special skills from leaders. Many of these reflect leadership s...

  16. Sensors in Smart Phone

    OpenAIRE

    Pei, Chunmei; Guo, Huiling; Yang, Xiuqing; Wang, Yangqiu; Zhang, Xiaojing; Ye, Hairong

    2010-01-01

    International audience; The technological innovation in electronics makes nowadays mobile phone more than a simple communication tool: it becomes a portable electronic device with integrated functions, such as listening to music, watching movies, taking photos, etc. To achieve these, many kinds of advanced sensor are used. In this paper, several applications of sensor in smart phone are introduced including Image Sensor, Fingerprint Identification Sensor, Photo-electric Sensor, Acceleration S...

  17. Game-Based Virtual Worlds as Decentralized Virtual Activity Systems

    Science.gov (United States)

    Scacchi, Walt

    There is widespread interest in the development and use of decentralized systems and virtual world environments as possible new places for engaging in collaborative work activities. Similarly, there is widespread interest in stimulating new technological innovations that enable people to come together through social networking, file/media sharing, and networked multi-player computer game play. A decentralized virtual activity system (DVAS) is a networked computer supported work/play system whose elements and social activities can be both virtual and decentralized (Scacchi et al. 2008b). Massively multi-player online games (MMOGs) such as World of Warcraft and online virtual worlds such as Second Life are each popular examples of a DVAS. Furthermore, these systems are beginning to be used for research, deve-lopment, and education activities in different science, technology, and engineering domains (Bainbridge 2007, Bohannon et al. 2009; Rieber 2005; Scacchi and Adams 2007; Shaffer 2006), which are also of interest here. This chapter explores two case studies of DVASs developed at the University of California at Irvine that employ game-based virtual worlds to support collaborative work/play activities in different settings. The settings include those that model and simulate practical or imaginative physical worlds in different domains of science, technology, or engineering through alternative virtual worlds where players/workers engage in different kinds of quests or quest-like workflows (Jakobsson 2006).

  18. Psychometric assessment and behavioral experiments using a free virtual reality platform and computational science.

    Science.gov (United States)

    Cipresso, Pietro; Serino, Silvia; Riva, Giuseppe

    2016-03-19

    Virtual Reality has been extensively used in a wide range of psychological experiments. In this study, we aimed to introduce NeuroVirtual 3D, a platform that clinicians could use free of charge. The platform we developed relies on NeuroVR software, but we extended it to apply to experiments. The software is available free of charge to researchers and clinical practitioners who can also use a large number of virtual environments and objects already developed. The platform has been developed to connect to virtually every device ever produced by the means of Virtual-Reality Peripheral Network (VRPN) protocols; however, a number of these have already been included and tested in the platform. Among the available devices, the Microsoft Kinect low-cost sensor has already been configured for navigation through the virtual environments and to trigger specific action (sounds, videos, images, and the like) when a specific gesture is recognized, e.g., a step forward or an arm up. A task for neglect and a task for spatial abilities assessment were already implemented within the platform. Moreover, NeuroVirtual 3D integrated a TCP-IP-based module (bridge) to collect the data from virtually any existent biosensor (Thought-Technology, Zephyr and StarStim devices have already been included in the platform). It is able to record any psychophysiological signal during any experiment using also the computed indices in real time. NeuroVirtual 3D is able to record external and internal (e.g., coordinates, keys-press, timestamp) data with a millisecond precision, representing de facto the most advanced technology for experimental psychology using virtual environments available without the needs to program code.

  19. CEDS Addresses: Virtual and Blended Learning

    Science.gov (United States)

    US Department of Education, 2015

    2015-01-01

    The Common Education Data Standards (CEDS) common data vocabulary supports the collection and use of information about virtual and blended learning. The data element "Virtual Indicator", introduced in version 3 of CEDS, supports a range of virtual learning-related use cases. The Virtual Indicator element may be related to a Course…

  20. A Review of Virtual Character's Emotion Model

    Science.gov (United States)

    Liu, Zhen

    2008-11-01

    Emotional virtual characters are essential to digital entertainment, an emotion is related to virtual environment and a virtual character's inner variables, emotion model of virtual character is a hot topic in many fields, domain knowledge is very important for modeling emotion, and the current research of emotion expression in the world was also summarized, and some new research directions of emotion model are presented.

  1. Image Based Rendering and Virtual Reality

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    The Presentation concerns with an overview of Image Based Rendering approaches and their use on Virtual Reality, including Virtual Photography and Cinematography, and Mobile Robot Navigation.......The Presentation concerns with an overview of Image Based Rendering approaches and their use on Virtual Reality, including Virtual Photography and Cinematography, and Mobile Robot Navigation....

  2. Constraint, Intelligence, and Control Hierarchy in Virtual Environments. Chapter 1

    Science.gov (United States)

    Sheridan, Thomas B.

    2007-01-01

    This paper seeks to deal directly with the question of what makes virtual actors and objects that are experienced in virtual environments seem real. (The term virtual reality, while more common in public usage, is an oxymoron; therefore virtual environment is the preferred term in this paper). Reality is difficult topic, treated for centuries in those sub-fields of philosophy called ontology- "of or relating to being or existence" and epistemology- "the study of the method and grounds of knowledge, especially with reference to its limits and validity" (both from Webster s, 1965). Advances in recent decades in the technologies of computers, sensors and graphics software have permitted human users to feel present or experience immersion in computer-generated virtual environments. This has motivated a keen interest in probing this phenomenon of presence and immersion not only philosophically but also psychologically and physiologically in terms of the parameters of the senses and sensory stimulation that correlate with the experience (Ellis, 1991). The pages of the journal Presence: Teleoperators and Virtual Environments have seen much discussion of what makes virtual environments seem real (see, e.g., Slater, 1999; Slater et al. 1994; Sheridan, 1992, 2000). Stephen Ellis, when organizing the meeting that motivated this paper, suggested to invited authors that "We may adopt as an organizing principle for the meeting that the genesis of apparently intelligent interaction arises from an upwelling of constraints determined by a hierarchy of lower levels of behavioral interaction. "My first reaction was "huh?" and my second was "yeah, that seems to make sense." Accordingly the paper seeks to explain from the author s viewpoint, why Ellis s hypothesis makes sense. What is the connection of "presence" or "immersion" of an observer in a virtual environment, to "constraints" and what types of constraints. What of "intelligent interaction," and is it the intelligence of the

  3. Kinematic Skeleton Based Control of a Virtual Simulator for Military Training

    Directory of Open Access Journals (Sweden)

    Soyeon Lee

    2015-06-01

    Full Text Available Virtual simulation technology has been considered as a highly efficient and cost-effective solution for a soldier training system, and evolved into diverse combinations of hardware and software. To maximize the virtual reality effect within a restricted space, a locomotion interface such as an omni-directional treadmill is introduced as a major component of a virtual simulator, therefore real time interaction between human and the virtual simulator becomes very important. Displacement and heading changes of the trainee are crucial information to control the virtual simulator when we implement highly reactive motion control for the omni-directional treadmill and interaction control of the virtual contents. This paper proposes a control parameter estimation algorithm for the virtual training simulator by using two types of motion capture sensors and presents the experimental results. Kinematic joint positions are analyzed to estimate the trainee’s location and velocity for feedback and feedforward control of the omni-directional treadmill. The accuracy of two approaches is evaluated by comparing with the reference system, which gives a ground truth value.

  4. Effects of virtual human animation on emotion contagion in simulated inter-personal experiences.

    Science.gov (United States)

    Wu, Yanxiang; Babu, Sabarish V; Armstrong, Rowan; Bertrand, Jeffrey W; Luo, Jun; Roy, Tania; Daily, Shaundra B; Dukes, Lauren Cairco; Hodges, Larry F; Fasolino, Tracy

    2014-04-01

    We empirically examined the impact of virtual human animation on the emotional responses of participants in a medical virtual reality system for education in the signs and symptoms of patient deterioration. Participants were presented with one of two virtual human conditions in a between-subjects experiment, static (non-animated) and dynamic (animated). Our objective measures included the use of psycho-physical Electro Dermal Activity (EDA) sensors, and subjective measures inspired by social psychology research included the Differential Emotions Survey (DES IV) and Positive and Negative Affect Survey (PANAS). We analyzed the quantitative and qualitative measures associated with participants’ emotional state at four distinct time-steps in the simulated interpersonal experience as the virtual patient’s medical condition deteriorated. Results suggest that participants in the dynamic condition with animations exhibited a higher sense of co-presence and greater emotional response as compared to participants in the static condition, corresponding to the deterioration in the medical condition of the virtual patient. Negative affect of participants in the dynamic condition increased at a higher rate than for participants in the static condition. The virtual human animations elicited a stronger response in negative emotions such as anguish, fear, and anger as the virtual patient’s medical condition worsened.

  5. Saving Money and Time with Virtual Server

    CERN Document Server

    Sanders, Chris

    2006-01-01

    Microsoft Virtual Server 2005 consistently proves to be worth its weight in gold, with new implementations thought up every day. With this product now a free download from Microsoft, scores of new users are able to experience what the power of virtualization can do for their networks. This guide is aimed at network administrators who are interested in ways that Virtual Server 2005 can be implemented in their organizations in order to save money and increase network productivity. It contains information on setting up a virtual network, virtual consolidation, virtual security, virtual honeypo

  6. Virtual Reality and Public Administration

    Directory of Open Access Journals (Sweden)

    István TÓZSA

    2013-02-01

    Full Text Available This study serves as an introduction to how virtual reality systems could be applied in public administration and what research tasks would be necessary to accomplish a project. E-government solutions began to emerge in public administration approximately a decade ago all over the developed world. Administration service facilities via the Internet did not attract many customers, because of the digital divide. E-government solutions were extended to mobile devices as well, but the expected breakthrough of usage has not ensued. The virtual reality form of public administration services recommended in this study has the most attractive outlay and the simplest navigation tools if compared to ‘traditional’ Internet based e-government. Thus, in accordance with the worldwide amazingly quick spread of the virtual reality systems of Second Life and 3 D types of entertainment, virtual reality applications in public administration could rely on a wide range of acceptance as well.

  7. ENHANCING SPIRITUALISM IN VIRTUAL WORLD

    Directory of Open Access Journals (Sweden)

    Kiran Lata DANGWAL

    2012-04-01

    Full Text Available Spiritualism is one word which puts man on the highest plinth of life. Spirituality is the way we find meaning, hope, comfort and inner peace in life. Spirituality in the virtual World is generally known as Virtual Spirituality. A goldmine of wisdom from all kinds of religious and spiritual philosophies, traditions and practices can be found in virtual World now. Technology and Spirituality together forms the material to which man can incline on to and work for the development of a globe in which war will be considered a taboo and violence a rejected dogma. Therefore there is an urgent nee to made the world a safe place to live in and the spiritual reconstruction can help us in achieving this.Spiritualism, Virtual World, Online Technology.

  8. Virtual gap dielectric wall accelerator

    Science.gov (United States)

    Caporaso, George James; Chen, Yu-Jiuan; Nelson, Scott; Sullivan, Jim; Hawkins, Steven A

    2013-11-05

    A virtual, moving accelerating gap is formed along an insulating tube in a dielectric wall accelerator (DWA) by locally controlling the conductivity of the tube. Localized voltage concentration is thus achieved by sequential activation of a variable resistive tube or stalk down the axis of an inductive voltage adder, producing a "virtual" traveling wave along the tube. The tube conductivity can be controlled at a desired location, which can be moved at a desired rate, by light illumination, or by photoconductive switches, or by other means. As a result, an impressed voltage along the tube appears predominantly over a local region, the virtual gap. By making the length of the tube large in comparison to the virtual gap length, the effective gain of the accelerator can be made very large.

  9. Affective appraisal of virtual environments

    NARCIS (Netherlands)

    Houtkamp, J.M.

    2012-01-01

    Interactive navigable 3D visualisations of built and natural environments have become commonplace in design and planning of urban environments and landscapes, and are regarded as potent prototyping and communication tools. In training applications, for instance for fire fighters, virtual

  10. Virtual Satellite Integration Environment Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advatech Pacific proposes to develop a Virtual Satellite Integration Environment (VSIE) for the NASA Ames Mission Design Center. The VSIE introduces into NASA...

  11. Time-Predictable Virtual Memory

    DEFF Research Database (Denmark)

    Puffitsch, Wolfgang; Schoeberl, Martin

    2016-01-01

    Virtual memory is an important feature of modern computer architectures. For hard real-time systems, memory protection is a particularly interesting feature of virtual memory. However, current memory management units are not designed for time-predictability and therefore cannot be used...... in such systems. This paper investigates the requirements on virtual memory from the perspective of hard real-time systems and presents the design of a time-predictable memory management unit. Our evaluation shows that the proposed design can be implemented efficiently. The design allows address translation...... and address range checking in constant time of two clock cycles on a cache miss. This constant time is in strong contrast to the possible cost of a miss in a translation look-aside buffer in traditional virtual memory organizations. Compared to a platform without a memory management unit, these two additional...

  12. The Virtual Campus Hub Concept

    DEFF Research Database (Denmark)

    Badger, Merete; Prag, Sidsel-Marie Winther; Monaco, Lucio

    The research infrastructure project Virtual Campus Hub (VCH) runs from October 1, 2011 to September 30, 2013. Four technical universities in Europe, who are all active in the field of sustainable energy, form the project consortium: the Technical University of Denmark, The Royal Institute...... of Technology in Sweden, Politecnico di Torino in Italy, and Eindhoven University of Technology in the Netherlands. The project is partially funded by the European Commission under the 7th Framework Programme (project no. RI-283746). This report describes the final concept of Virtual Campus Hub. It gives...... an overview of the project achievements and recommends best practices for the use of the Virtual Campus Hub elements: a series of applications for online teaching and collaboration which are connected to a technical platform, the Virtual Campus Hub portal, using the European research infrastructure Géant/eduGAIN....

  13. Dynamic Virtual Credit Card Numbers

    Science.gov (United States)

    Molloy, Ian; Li, Jiangtao; Li, Ninghui

    Theft of stored credit card information is an increasing threat to e-commerce. We propose a dynamic virtual credit card number scheme that reduces the damage caused by stolen credit card numbers. A user can use an existing credit card account to generate multiple virtual credit card numbers that are either usable for a single transaction or are tied with a particular merchant. We call the scheme dynamic because the virtual credit card numbers can be generated without online contact with the credit card issuers. These numbers can be processed without changing any of the infrastructure currently in place; the only changes will be at the end points, namely, the card users and the card issuers. We analyze the security requirements for dynamic virtual credit card numbers, discuss the design space, propose a scheme using HMAC, and prove its security under the assumption the underlying function is a PRF.

  14. Virtual reality 3D headset based on DMD light modulators

    Energy Technology Data Exchange (ETDEWEB)

    Bernacki, Bruce E.; Evans, Allan; Tang, Edward

    2014-06-13

    We present the design of an immersion-type 3D headset suitable for virtual reality applications based upon digital micro-mirror devices (DMD). Our approach leverages silicon micro mirrors offering 720p resolution displays in a small form-factor. Supporting chip sets allow rapid integration of these devices into wearable displays with high resolution and low power consumption. Applications include night driving, piloting of UAVs, fusion of multiple sensors for pilots, training, vision diagnostics and consumer gaming. Our design is described in which light from the DMD is imaged to infinity and the user’s own eye lens forms a real image on the user’s retina.

  15. Virtual Induction Loops Based on Cooperative Vehicular Communications

    Directory of Open Access Journals (Sweden)

    Maria Calderon

    2013-01-01

    Full Text Available Induction loop detectors have become the most utilized sensors in traffic management systems. The gathered traffic data is used to improve traffic efficiency (i.e., warning users about congested areas or planning new infrastructures. Despite their usefulness, their deployment and maintenance costs are expensive. Vehicular networks are an emerging technology that can support novel strategies for ubiquitous and more cost-effective traffic data gathering. In this article, we propose and evaluate VIL (Virtual Induction Loop, a simple and lightweight traffic monitoring system based on cooperative vehicular communications. The proposed solution has been experimentally evaluated through simulation using real vehicular traces.

  16. Virtual learning environments: second life.

    Science.gov (United States)

    Ahern, Nancy; Wink, Diane M

    2010-01-01

    In this bimonthly series, the authors examine how nurse educators can use the Internet and Web-based computer technologies such as search, communication, collaborative writing tools; social networking and social bookmarking sites; virtual worlds; and Web-based teaching and learning programs. The editor of this column and her coauthor describes how the virtual world of Second Life can be used in nursing education.

  17. Virtual Technologies and Social Shaping

    OpenAIRE

    Kreps, David

    2010-01-01

    International audience; Virtual Technologies have enabled us all to become publishers and broadcasters. The world of information has become saturated with a multitude of opinions, and opportunities to express them. Track 2 "Virtual Technologies and Social Shaping" of the 9th Conference on Human Choice and Computers (HCC9) explores some of the issues that have arisen in this new information society, how we are shaped by it, and how we shape it, through i) two papers addressing issues of identi...

  18. Portable Userspace Virtual Filesystem Switch

    OpenAIRE

    Łukasz Faber; Krzysztof Boryczko

    2013-01-01

    Multiple different filesystems — including disk-based, network, distributed, abstract — arean integral part of every operating system. They are usually written as kernel modules and abstracted to the user via a virtual filesystem switch. In this paper we analyse the feasibility of reimplementing the virtual filesystem switch as a userspace daemon and applicability of this approach in real-life usage. Such reimplementation will require a way to virtualise processes behaviour related to filesys...

  19. Interaction techniques in virtual environments

    OpenAIRE

    Moya Santos, Sergio; Grau, Sergi; Tost Pardell, Daniela

    2013-01-01

    Virtual environments are used in very diverse applications: from leisure games to professional training and rehabilitation systems. In these applications, users interact with the elements of the environments through avatars in order to perform virtually actions such as picking objects, carrying and dropping them, and more complex manipulations tasks such as cutting and drilling in surgery training, shooting and punching in actions games, and cooking and cleaning in life simulation games an...

  20. Vagrant virtual development environment cookbook

    CERN Document Server

    Thompson, Chad

    2015-01-01

    If you are a software developer or administrator who wishes to create simple, reusable environments using Vagrant, this book is the perfect choice for you. Whether you are a system administrator with extensive experience in virtualization or a developer wishing to create development scripts for cloud deployment, you will find easy-to-follow recipes and techniques in this book that will allow you to create robust and reproducible virtual environments.

  1. Magnetically suspended virtual divergent channel

    Energy Technology Data Exchange (ETDEWEB)

    Yamane, Ryuichiro [Kokushikan University, 4-28-1 Setagaya, Setagaya-ku, Tokyo 154-8515 (Japan)]. E-mail: yamane@kokushikan.ac.jp; Oshiama, Shuzo [Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552 (Japan); Park, Myeong-Kwan [Pusan National University, 30 Changjeon-dong, Kumjeong-ku, Pusan 609-735 (Korea, Republic of)

    2005-03-15

    Two permanent magnets are set face-to-face and inclined with each other to produce the long cuspidal magnetic field. The diamagnetic liquid is levitated and flows through it without contact with the solid walls as if it is in the virtual divergent channel. Analysis is made on the shape of the virtual channel, and the results are compared with the experimental ones. The divergence angle increases with the increase in the inclination of the magnets.

  2. Reference Models for Virtual Enterprises

    DEFF Research Database (Denmark)

    Tølle, Martin; Bernus, Peter; Vesterager, Johan

    2002-01-01

    This paper analyses different types of Reference Models (RMs) applicable to support the set up and (re)configuration of virtual enterprises (VEs). RMs are models capturing concepts common to VEs aiming to convert the task of setting up of VE towards a configuration task, and hence reduce the time...... needed for VE creation. The RMs are analysed through a mapping onto the Virtual Enterprise Reference Architecture (VERA) created in the IMS GLOBEMEN project based upon GERAM....

  3. Social desirability in virtual communities

    OpenAIRE

    Massara, F; Ancarani, F; Costabile, M; RICOTTA, F.

    2012-01-01

    As virtual worlds and social media in general become important settings for marketing actions, we need to know what is the weight of social norms within such contexts. To what degree can a researcher expect that the answers obtained within a virtual world ¨C ultimately a social network ¨C reflect real opinions and are not inflated by social desirability? Does the social context of an online community induce higher social desirability? This paper investigates whether social desirability is str...

  4. Training Rowing with Virtual Environments

    Directory of Open Access Journals (Sweden)

    Gopher Daniel

    2011-12-01

    Full Text Available This paper presents the results of the design, implementation and evaluation of a platform for rowing training in Virtual Reality called SPRINT. The paper discusses how various aspects of the rowing skill can be analyzed and trained over a single common methodology and system platform. The result is a vision for new directions in the domain of sport training with Virtual Reality.

  5. The Virtual Robotics Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Kress, R.L.; Love, L.J.

    1999-09-01

    The growth of the Internet has provided a unique opportunity to expand research collaborations between industry, universities, and the national laboratories. The Virtual Robotics Laboratory (VRL) is an innovative program at Oak Ridge National Laboratory (ORNL) that is focusing on the issues related to collaborative research through controlled access of laboratory equipment using the World Wide Web. The VRL will provide different levels of access to selected ORNL laboratory secondary education programs. In the past, the ORNL Robotics and Process Systems Division has developed state-of-the-art robotic systems for the Army, NASA, Department of Energy, Department of Defense, as well as many other clients. After proof of concept, many of these systems sit dormant in the laboratories. This is not out of completion of all possible research topics. but from completion of contracts and generation of new programs. In the past, a number of visiting professors have used this equipment for their own research. However, this requires that the professor, and possibly his/her students, spend extended periods at the laboratory facility. In addition, only a very exclusive group of faculty can gain access to the laboratory and hardware. The VRL is a tool that enables extended collaborative efforts without regard to geographic limitations.

  6. Portable Virtual Training Units

    Science.gov (United States)

    Malone, Reagan; Johnston, Alan

    2015-01-01

    The Mission Operations Lab initiated a project to design, develop, deliver, test, and validate a unique training system for astronaut and ground support personnel. In an effort to keep training costs low, virtual training units (VTUs) have been designed based on images of actual hardware and manipulated by a touch screen style interface for ground support personnel training. This project helped modernized the training system and materials by integrating them with mobile devices for training when operators or crew are unavailable to physically train in the facility. This project also tested the concept of a handheld remote device to control integrated trainers using International Space Station (ISS) training simulators as a platform. The portable VTU can interface with the full-sized VTU, allowing a trainer co-located with a trainee to remotely manipulate a VTU and evaluate a trainee's response. This project helped determine if it is useful, cost effective, and beneficial for the instructor to have a portable handheld device to control the behavior of the models during training. This project has advanced NASA Marshall Space Flight Center's (MSFC's) VTU capabilities with modern and relevant technology to support space flight training needs of today and tomorrow.

  7. The Virtual Robotics Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Kress, R.L. [Oak Ridge National Lab., TN (United States); Love, L.J. [Oak Ridge Inst. for Science and Education, TN (United States)

    1997-03-01

    The growth of the Internet has provided a unique opportunity to expand research collaborations between industry, universities, and the national laboratories. The Virtual Robotics Laboratory (VRL) is an innovative program at Oak Ridge National Laboratory (ORNL) that is focusing on the issues related to collaborative research through controlled access of laboratory equipment using the World Wide Web. The VRL will provide different levels of access to selected ORNL laboratory equipment to outside universities, industrial researchers, and elementary and secondary education programs. In the past, the ORNL Robotics and Process Systems Division (RPSD) has developed state-of-the-art robotic systems for the Army, NASA, Department of Energy, Department of Defense, as well as many other clients. After proof of concept, many of these systems sit dormant in the laboratories. This is not out of completion of all possible research topics, but from completion of contracts and generation of new programs. In the past, a number of visiting professors have used this equipment for their own research. However, this requires that the professor, and possibly his students, spend extended periods at the laboratory facility. In addition, only a very exclusive group of faculty can gain access to the laboratory and hardware. The VRL is a tool that enables extended collaborative efforts without regard to geographic limitations.

  8. [Virtual room of gastroenterology].

    Science.gov (United States)

    Spinelli, Osvaldo Mateo; Fittipaldi, Mónica Elsa; Henderson, Eduardo; Krabshuis, Justus Hendrik

    2010-12-01

    The amount of published information and its continuing growth can no longer be managed by an individual searcher. One of today's great challenges for the academic researcher and clinician is to find a relevant scientific article using bibliographic search strategies. We aimed to design and build a Virtual Room of Gastroenterology (VRG) generating real-time automated search strategies and producing bibliographic and full text search results. These results update and complement with the latest evidence the Clinical Guideline Program of the World Gastroenterology Organisation. The HTML driven interface provides a series of pre-formulated MeSH based search strategies for each Aula. For each topic between 10 and 20 specific terms, qualifiers and subheadings are identified. The functionality of the VRG is based on the PubMed's characteristic that allows a search strategy to be captured as a web address. The VRG is available in Spanish and English, and the access is free. There are 28 rooms currently available. All together these rooms provide an advanced bibliographic access using more than 900 pre-programmed MeSH driven strategies. In a further very recent development some of the topics of VRG now allow cascade based searches. These searches look at resource sensitive options and possible ethnic difference per topic. The VRG allows significant reductions in time required to design and carry out complex bibliographic searches in the areas of gastroenterology, hepatology and endoscopy. The system updates automatically in real-time thus ensuring the currency of the results.

  9. Virtual art revisited

    Science.gov (United States)

    Ruzanka, S.

    2014-02-01

    Virtual reality art at the turn of the millenium saw an explosion of creative exploration around this nascent technoloy. Though VR art has much in common with media art in general, the affordances of the technology gave rise to unique experiences, discourses, and artistic investigations. Women artists were at the forefront of the medium, shaping its aesthetic and technical development, and VR fostered a range of artistic concerns and experimentation that was largely distinct from closely related forms such as digital games. Today, a new wave of consumer technologies including 3D TV's, gestural and motion tracking interfaces, and headmount displays as viable, low-cost gaming peripherals drives a resurgence in interest in VR for interactive art and entertainment. Designers, game developers, and artists working with these technologies are in many cases discovering them anew. This paper explores ways of reconnecting this current moment in VR with its past. Can the artistic investigations begun in previous waves of VR be continued? How do the similarities and differences in contexts, communities, technologies, and discourses affect the development of the medium?

  10. What makes virtual agents believable?

    Science.gov (United States)

    Bogdanovych, Anton; Trescak, Tomas; Simoff, Simeon

    2016-01-01

    In this paper we investigate the concept of believability and make an attempt to isolate individual characteristics (features) that contribute to making virtual characters believable. As the result of this investigation we have produced a formalisation of believability and based on this formalisation built a computational framework focused on simulation of believable virtual agents that possess the identified features. In order to test whether the identified features are, in fact, responsible for agents being perceived as more believable, we have conducted a user study. In this study we tested user reactions towards the virtual characters that were created for a simulation of aboriginal inhabitants of a particular area of Sydney, Australia in 1770 A.D. The participants of our user study were exposed to short simulated scenes, in which virtual agents performed some behaviour in two different ways (while possessing a certain aspect of believability vs. not possessing it). The results of the study indicate that virtual agents that appear resource bounded, are aware of their environment, own interaction capabilities and their state in the world, agents that can adapt to changes in the environment and exist in correct social context are those that are being perceived as more believable. Further in the paper we discuss these and other believability features and provide a quantitative analysis of the level of contribution for each such feature to the overall perceived believability of a virtual agent.

  11. Virtual patients in geriatric education.

    Science.gov (United States)

    Tan, Zaldy S; Mulhausen, Paul L; Smith, Stephen R; Ruiz, Jorge G

    2010-01-01

    The virtual patient is a case-based computer program that combines textual information with multimedia elements such as audio, graphics, and animation. It is increasingly being utilized as a teaching modality by medical educators in various fields of instruction. The inherent complexity of older patients and the shortage of geriatrics educators have spurred the development of virtual patient programs to teach geriatrics at the medical undergraduate, graduate, and postgraduate levels. As an instructional tool, the Virtual Patient must be placed in the correct educational context to help educators identify opportunities for its proper use in the curriculum. In this review, the experiences of three medical schools in the development and application of geriatric virtual patients are described as case studies. In each case study, the challenges encountered and solutions developed are presented. Areas of future research in the use of virtual patients in geriatrics education include the determination of the optimal combination of features, the settings of use of virtual patient programs, the underlying pedagogy, and the limitations in its application in clinical instruction.

  12. ROLE OF VIRTUALIZATION IN CLOUD COMPUTING

    OpenAIRE

    Avneet kaur; Dr. Gaurav Gupta; Dr. Gurjit Singh Bhathal

    2017-01-01

    Cloud Computing is the fundamental change happening in the field of Information Technology.. Virtualization is the key component of cloud computing. With the use of virtualization, cloud computing brings about not only convenience and efficiency benefits, but also great challenges in the field of data security and privacy protection. .In this paper, we are discussing about virtualization, architecture of virtualization technology as well as Virtual Machine Monitor (VMM). Further discussing ab...

  13. Quiet Zone Enhancement for a Target Location Using an Improved Virtual Sensing Algorithm

    Directory of Open Access Journals (Sweden)

    Xiangbin Mu

    2017-10-01

    Full Text Available Generating a quiet zone at a target location is the ultimate goal of active noise control (ANC. Generally, the best noise cancellation is achieved at the locations of error sensors. However, the distribution of physical error sensors at a given location is not always convenient or feasible. To overcome this challenge, a number of virtual sensing algorithms for ANC have been researched. Using the physical error signals and knowledge of the system, the adaptive least mean square (LMS virtual sensing algorithm estimates the error signal at a location that is remote from the physical error sensor, referred to as the virtual location. It achieves excellent performance under the assumption that the unknown primary path is fixed, but its performance decreases significantly if the path is constantly changing. This paper presents a real-time ANC system with an improved virtual sensing algorithm to solve this problem. The proposed system was tested to enhance the quiet zone in a constantly changing environment; an enhanced quiet zone was created, and the noise cancellation, especially at the target location, obviously improved.

  14. Virtual Globes, where we were, are and will be

    Science.gov (United States)

    Dehn, J.; Webley, P. W.; Worden, A. K.

    2016-12-01

    Ten years ago, Google Earth was new, and the first "Virtual Globes" session was held at AGU. Only a few of us realized the potential of this technology at the time, but the idea quickly caught on. At that time a virtual globe came in two flavors, first a complex GIS system that was utterly impenetrable for the public, or a more accessible version with limited functionality and layers that was available on a desktop computer with a good internet connection. Google Earth's use of the Keyhole Markup Language opened the door for scientists and the public to share data and visualizations across disciplines and revolutionized how everyone uses geographic data. In the following 10 years, KML became more advanced, virtual globes moved to mobile and handheld platforms, and the Google Earth engine allowed for more complex data sharing among scientists. Virtual globe images went from a rare commodity to being everywhere in our lives, from weather forecasts, in our cars, on our smart-phones and shape how we receive and process data. This is a fantastic tool for education and with newer technologies can reach the the remote corners of the world and developing countries. New and emerging technologies allow for augmented reality to be merged with the globes, and for real-time data integration with sensors built into mobile devices or add-ons. This presentation will follow the history of virtual globes in the geosciences, show how robust technologies can be used in the field and classroom today, and make some suggestions for the future.

  15. Towards Sensor Database Systems

    DEFF Research Database (Denmark)

    Bonnet, Philippe; Gehrke, Johannes; Seshadri, Praveen

    2001-01-01

    . These systems lack flexibility because data is extracted in a predefined way; also, they do not scale to a large number of devices because large volumes of raw data are transferred regardless of the queries that are submitted. In our new concept of sensor database system, queries dictate which data is extracted...... from the sensors. In this paper, we define the concept of sensor databases mixing stored data represented as relations and sensor data represented as time series. Each long-running query formulated over a sensor database defines a persistent view, which is maintained during a given time interval. We...... also describe the design and implementation of the COUGAR sensor database system....

  16. Novel Virtual Environment for Alternative Treatment of Children with Cerebral Palsy

    Directory of Open Access Journals (Sweden)

    Juliana M. de Oliveira

    2016-01-01

    Full Text Available Cerebral palsy is a severe condition usually caused by decreased brain oxygenation during pregnancy, at birth or soon after birth. Conventional treatments for cerebral palsy are often tiresome and expensive, leading patients to quit treatment. In this paper, we describe a virtual environment for patients to engage in a playful therapeutic game for neuropsychomotor rehabilitation, based on the experience of the occupational therapy program of the Nucleus for Integrated Medical Assistance (NAMI at the University of Fortaleza, Brazil. Integration between patient and virtual environment occurs through the hand motion sensor “Leap Motion,” plus the electroencephalographic sensor “MindWave,” responsible for measuring attention levels during task execution. To evaluate the virtual environment, eight clinical experts on cerebral palsy were subjected to a questionnaire regarding the potential of the experimental virtual environment to promote cognitive and motor rehabilitation, as well as the potential of the treatment to enhance risks and/or negatively influence the patient’s development. Based on the very positive appraisal of the experts, we propose that the experimental virtual environment is a promising alternative tool for the rehabilitation of children with cerebral palsy.

  17. Designing reduced beacon trajectory for sensor localization

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Localization is one of the substantial issues in wireless sensor networks. The key problem for the mobile beacon localization is how to choose the appropriate beacon trajectory. However, little research has been done on it. In this paper, firstly,we deduce the number of positions for a beacon to send a packet according to the acreage of ROI (region of interest); and next we present a novel method based on virtual force to arrange the positions in arbitrary ROI; then we apply TSP (travelling salesman problem) algorithm to the positions sequence to obtain the optimal touring path, i.e. the reduced beacon trajectory. When a mobile beacon moves along the touring path, sending RF signals at every position, the sensors in ROI can work out their position with trilateration. Experimental results demonstrate that the localization method, based on the beacon reduced path, is efficient and has flexible accuracy.

  18. Distributed Sensor Network Software Development Testing through Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Brennan, Sean M. [Univ. of New Mexico, Albuquerque, NM (United States)

    2003-12-01

    The distributed sensor network (DSN) presents a novel and highly complex computing platform with dif culties and opportunities that are just beginning to be explored. The potential of sensor networks extends from monitoring for threat reduction, to conducting instant and remote inventories, to ecological surveys. Developing and testing for robust and scalable applications is currently practiced almost exclusively in hardware. The Distributed Sensors Simulator (DSS) is an infrastructure that allows the user to debug and test software for DSNs independent of hardware constraints. The exibility of DSS allows developers and researchers to investigate topological, phenomenological, networking, robustness and scaling issues, to explore arbitrary algorithms for distributed sensors, and to defeat those algorithms through simulated failure. The user speci es the topology, the environment, the application, and any number of arbitrary failures; DSS provides the virtual environmental embedding.

  19. Virtual Reference Interferometry: Theory & Experiment

    Science.gov (United States)

    Galle, Michael Anthony

    This thesis introduces the idea that a simulated interferogram can be used as a reference for an interferometer. This new concept represents a paradigm shift from the conventional thinking, where a reference is the phase of a wavefront that traverses a known path. The simulated interferogram used as a reference is called a virtual reference. This thesis develops the theory of virtual reference interferometry and uses it for the characterization of chromatic dispersion in short length (design to nonlinear photonics, sensing and communications. Techniques for short-length dispersion characterization are therefore critical to the development of many photonic systems. The current generation of short-length dispersion measurement techniques are either easy to operate but lack sufficient accuracy, or have sufficient accuracy but are difficult to operate. The use of a virtual reference combines the advantages of these techniques so that it is both accurate and easy to operate. Chromatic dispersion measurements based on virtual reference interferometry have similar accuracy as the best conventional measurement techniques due to the ability to measure first and second order dispersion directly from the interference pattern. Unique capabilities of virtual reference interferometry are demonstrated, followed by a derivation of the operational constraints and system parameters. The technique is also applied to the characterization of few-mode fibers, a hot topic in telecommunications research where mode division multiplexing promises to expand network bandwidth. Also introduced is the theory of dispersive virtual reference interferometry, which can be used to overcome the bandwidth limitations associated with the measurement of near-zero dispersion-length optical components via compression of the interference pattern. Additionally, a method for utilizing the virtual reference interferometer in a low-coherence setup is introduced, enabling characterization in new wavelength

  20. A New User Interface for On-Demand Customizable Data Products for Sensors in a SensorWeb

    Science.gov (United States)

    Mandl, Daniel; Cappelaere, Pat; Frye, Stuart; Sohlberg, Rob; Ly, Vuong; Chien, Steve; Sullivan, Don

    2011-01-01

    A SensorWeb is a set of sensors, which can consist of ground, airborne and space-based sensors interoperating in an automated or autonomous collaborative manner. The NASA SensorWeb toolbox, developed at NASA/GSFC in collaboration with NASA/JPL, NASA/Ames and other partners, is a set of software and standards that (1) enables users to create virtual private networks of sensors over open networks; (2) provides the capability to orchestrate their actions; (3) provides the capability to customize the output data products and (4) enables automated delivery of the data products to the users desktop. A recent addition to the SensorWeb Toolbox is a new user interface, together with web services co-resident with the sensors, to enable rapid creation, loading and execution of new algorithms for processing sensor data. The web service along with the user interface follows the Open Geospatial Consortium (OGC) standard called Web Coverage Processing Service (WCPS). This presentation will detail the prototype that was built and how the WCPS was tested against a HyspIRI flight testbed and an elastic computation cloud on the ground with EO-1 data. HyspIRI is a future NASA decadal mission. The elastic computation cloud stores EO-1 data and runs software similar to Amazon online shopping.

  1. Estimation of Image Sensor Fill Factor Using a Single Arbitrary Image

    Directory of Open Access Journals (Sweden)

    Wei Wen

    2017-03-01

    Full Text Available Achieving a high fill factor is a bottleneck problem for capturing high-quality images. There are hardware and software solutions to overcome this problem. In the solutions, the fill factor is known. However, this is an industrial secrecy by most image sensor manufacturers due to its direct effect on the assessment of the sensor quality. In this paper, we propose a method to estimate the fill factor of a camera sensor from an arbitrary single image. The virtual response function of the imaging process and sensor irradiance are estimated from the generation of virtual images. Then the global intensity values of the virtual images are obtained, which are the result of fusing the virtual images into a single, high dynamic range radiance map. A non-linear function is inferred from the original and global intensity values of the virtual images. The fill factor is estimated by the conditional minimum of the inferred function. The method is verified using images of two datasets. The results show that our method estimates the fill factor correctly with significant stability and accuracy from one single arbitrary image according to the low standard deviation of the estimated fill factors from each of images and for each camera.

  2. Developing a Virtual Book – Material for Virtual Learning Environments

    Directory of Open Access Journals (Sweden)

    Morten Fahlvik

    2007-11-01

    Full Text Available This article describes the process of, and considerations taken when Virtual Learning Materials were developed for an international study in Comparative Social Work arranged by the VIRCLASS project. The steps taken and the elements included in the Virtual Book – A Guide to Social Work in Europe are presented in details to inform others who are planning to make virtual learning materials. Students from 11 countries in Europe participated, and their reception of this material and learning outcomes from using it are analysed and presented. Furthermore; the article discuss how the learning material contributes to students’ learning, how a common understanding of practice enhances knowledge-building and in what way audio-visual learning material can contribute to good learning in e-learning courses. The results are discussed in relation to theories about composite texts and community of inquiry, and outlines some challenges for e-teachers’ competences.

  3. Embedded sensor systems

    CERN Document Server

    Agrawal, Dharma Prakash

    2017-01-01

    This inspiring textbook provides an introduction to wireless technologies for sensors, explores potential use of sensors for numerous applications, and utilizes probability theory and mathematical methods as a means of embedding sensors in system design. It discusses the need for synchronization and underlying limitations, inter-relation between given coverage and connectivity to number of sensors needed, and the use of geometrical distance to determine location of the base station for data collection and explore use of anchor nodes for relative position determination of sensors. The book explores energy conservation, communication using TCP, the need for clustering and data aggregation, and residual energy determination and energy harvesting. It covers key topics of sensor communication like mobile base stations and relay nodes, delay-tolerant sensor networks, and remote sensing and possible applications. The book defines routing methods and do performance evaluation for random and regular sensor topology an...

  4. Air Sensor Toolbox

    Science.gov (United States)

    Air Sensor Toolbox provides information to citizen scientists, researchers and developers interested in learning more about new lower-cost compact air sensor technologies and tools for measuring air quality.

  5. Contenidos virtuales para neurorrehabilitación funcional de la extremidad superior

    OpenAIRE

    Molina Nájera, Fernando; Almenar Masbernat, M.; Ontiveros Ravell, J.; Gómez, C; Villán Villán, M.A.; Pérez Rodríguez, R.; Martín, C; Opisso, Eloy; Medina Casanovas, J.; Tormos Muñoz, José M.; Gómez Aguilera, Enrique J.

    2015-01-01

    La utilización de entornos virtuales de rehabilitación que hacen uso de dispositivos comerciales para el entretenimiento ha adquirido un gran interés en el área de neurorrehabilitación. El objetivo del presente trabajo es diseñar y desarrollar contenidos virtuales (CVs) para rehabilitación funcional en pacientes con Traumatismo Craneoencefálico (TCE). Para ello se han diseñado dos actividades de rehabilitación que hacen uso del sensor de profundidad de bajo coste Microsoft Kinect junto con di...

  6. Biomedical Sensors of Ionizing Radiation

    OpenAIRE

    Pani, S; Speller, R; Royle, G; Olivo, A

    2010-01-01

    Sensors Technology Series Editor-in-Chief's Preface vii Preface ix 1 Biomedical Sensors: Temperature Sensor ... G. Kim Prisk 4 Biomedical Sensors of Ionizing Radiation 129 Robert Speller, Alessandro Olivo, Silvia Pani, and Gary Royle 5 ...

  7. Digital Sensor Technology

    Energy Technology Data Exchange (ETDEWEB)

    Ted Quinn; Jerry Mauck; Richard Bockhorst; Ken Thomas

    2013-07-01

    The nuclear industry has been slow to incorporate digital sensor technology into nuclear plant designs due to concerns with digital qualification issues. However, the benefits of digital sensor technology for nuclear plant instrumentation are substantial in terms of accuracy, reliability, availability, and maintainability. This report demonstrates these benefits in direct comparisons of digital and analog sensor applications. It also addresses the qualification issues that must be addressed in the application of digital sensor technology.

  8. Acoustic Humidity Sensor

    Science.gov (United States)

    Shakkottai, Parthasarathy; Kwack, Eug Y.; Venkateshan, Shakkottai

    1990-01-01

    Industrial humidity sensor measures volume fraction of water in air via its effect on speed of sound. Only portion of sensor exposed to sensed atmosphere is pair of stainless-steel tubes, one containing dry air and other containing moist air. Counters measure intervals between reflected pulses. Sensor rugged enough for use in harsh environments like those used to control drying of paper in paper mills, where most humidity sensors do not survive.

  9. Motor rehabilitation using virtual reality

    Directory of Open Access Journals (Sweden)

    Sveistrup Heidi

    2004-12-01

    Full Text Available Abstract Virtual Reality (VR provides a unique medium suited to the achievement of several requirements for effective rehabilitation intervention. Specifically, therapy can be provided within a functional, purposeful and motivating context. Many VR applications present opportunities for individuals to participate in experiences, which are engaging and rewarding. In addition to the value of the rehabilitation experience for the user, both therapists and users benefit from the ability to readily grade and document the therapeutic intervention using various systems. In VR, advanced technologies are used to produce simulated, interactive and multi-dimensional environments. Visual interfaces including desktop monitors and head-mounted displays (HMDs, haptic interfaces, and real-time motion tracking devices are used to create environments allowing users to interact with images and virtual objects in real-time through multiple sensory modalities. Opportunities for object manipulation and body movement through virtual space provide frameworks that, in varying degrees, are perceived as comparable to similar opportunities in the real world. This paper reviews current work on motor rehabilitation using virtual environments and virtual reality and where possible, compares outcomes with those achieved in real-world applications.

  10. Motor rehabilitation using virtual reality.

    Science.gov (United States)

    Sveistrup, Heidi

    2004-12-10

    Virtual Reality (VR) provides a unique medium suited to the achievement of several requirements for effective rehabilitation intervention. Specifically, therapy can be provided within a functional, purposeful and motivating context. Many VR applications present opportunities for individuals to participate in experiences, which are engaging and rewarding. In addition to the value of the rehabilitation experience for the user, both therapists and users benefit from the ability to readily grade and document the therapeutic intervention using various systems. In VR, advanced technologies are used to produce simulated, interactive and multi-dimensional environments. Visual interfaces including desktop monitors and head-mounted displays (HMDs), haptic interfaces, and real-time motion tracking devices are used to create environments allowing users to interact with images and virtual objects in real-time through multiple sensory modalities. Opportunities for object manipulation and body movement through virtual space provide frameworks that, in varying degrees, are perceived as comparable to similar opportunities in the real world. This paper reviews current work on motor rehabilitation using virtual environments and virtual reality and where possible, compares outcomes with those achieved in real-world applications.

  11. Virtual scarce water in China.

    Science.gov (United States)

    Feng, Kuishuang; Hubacek, Klaus; Pfister, Stephan; Yu, Yang; Sun, Laixiang

    2014-07-15

    Water footprints and virtual water flows have been promoted as important indicators to characterize human-induced water consumption. However, environmental impacts associated with water consumption are largely neglected in these analyses. Incorporating water scarcity into water consumption allows better understanding of what is causing water scarcity and which regions are suffering from it. In this study, we incorporate water scarcity and ecosystem impacts into multiregional input-output analysis to assess virtual water flows and associated impacts among 30 provinces in China. China, in particular its water-scarce regions, are facing a serious water crisis driven by rapid economic growth. Our findings show that inter-regional flows of virtual water reveal additional insights when water scarcity is taken into account. Consumption in highly developed coastal provinces is largely relying on water resources in the water-scarce northern provinces, such as Xinjiang, Hebei, and Inner Mongolia, thus significantly contributing to the water scarcity in these regions. In addition, many highly developed but water scarce regions, such as Shanghai, Beijing, and Tianjin, are already large importers of net virtual water at the expense of water resource depletion in other water scarce provinces. Thus, increasingly importing water-intensive goods from other water-scarce regions may just shift the pressure to other regions, but the overall water problems may still remain. Using the water footprint as a policy tool to alleviate water shortage may only work when water scarcity is taken into account and virtual water flows from water-poor regions are identified.

  12. Virtual materiality, potentiality and subjctivity

    DEFF Research Database (Denmark)

    Søndergaard, Dorte Marie

    2013-01-01

    How do we conceptualize virtual materiality, in terms of for instance avatars and weapons in computer games, virtual discourse and subjectivity as phenomena intra-acting with real life materiality, discourse and subjectivity in children’s everyday lives? How do we understand the intra-activity of......How do we conceptualize virtual materiality, in terms of for instance avatars and weapons in computer games, virtual discourse and subjectivity as phenomena intra-acting with real life materiality, discourse and subjectivity in children’s everyday lives? How do we understand the intra......-activity of such elements in children’s night dreams? These are some of the questions discussed in this text. I bring together Karen Barad’s agential realism and Giorgi Agamben’s concept of potentiality to enable and refine an analytical approach to real-virtual enactments, thereby questioning the potentialities of gaming......, of movies and of dreams as they enter intra-activities in the comprehensive set of apparatuses that enact child agency, subjectivity and relational practices. The analyses and conceptual refinements are based on empirical cases involving interviews with and observations among 8-14 year old children....

  13. A Virtual Tomb for Kelvingrove: Virtual Reality, Archaeology and Education

    Directory of Open Access Journals (Sweden)

    Melissa M. Terras

    1999-11-01

    Full Text Available The use of computers as an educational resource in museums is becoming increasingly popular as more and more institutions realise that multimedia displays are very successful in imparting a broad variety of information. Although three-dimensional reconstructions of sites and structures have been used in archaeology for many years, the majority of museum computer installations have dealt with two-dimensional media because of the costs, equipment and labour involved in producing interactive 3D scenes. The birth of VRML (Virtual Reality Modeling Language has changed the way virtual reality is implemented and viewed. As an internet protocol, VRML can be used on most major platforms and implemented by anyone with a word-processing package, an internet browser, and the relevant plug-in. There is no reason why this new technology cannot be adopted by archaeologists and museums to produce virtual reality models of structures, sites and objects to aid the research of specialists and the education of the public. This project (undertaken at the Humanities Advanced Technology and Information Institute, University of Glasgow, Scotland, between May and October 1998 investigated the practicalities involved in using VRML to create a virtual reality model for use in a public space. A model of the Egyptian tomb of Sen-nedjem was developed for installation in the Egyptian Gallery of the Kelvingrove Museum and Art Gallery, Glasgow, in the hope that the introduction of this computer display would encourage the museum visitor's interest in the gallery's existing artefacts. Creation of the model would also investigate the possibility of using VRML to build accurate archaeological reconstructions cheaply and efficiently using publicly available software and existing archaeological resources. A fully functioning virtual reality model of the tomb of Sen-nedjem has been created, incorporating interactive elements, photorealistic representation, and animation, and this

  14. Laser sensor system documentation.

    Science.gov (United States)

    2017-03-01

    Phase 1 of TxDOT Project 0-6873, True Road Surface Deflection Measuring Device, developed a : laser sensor system based on several sensors mounted on a rigid beam. : This sensor system remains with CTR currently, as the project is moving into Phase 2...

  15. Sensors for Entertainment

    Directory of Open Access Journals (Sweden)

    Fabrizio Lamberti

    2016-07-01

    Full Text Available Sensors are becoming ubiquitous in all areas of science, technology, and society. In this Special Issue on “Sensors for Entertainment”, developments in progress and the current state of application scenarios for sensors in the field of entertainment is explored.

  16. Sensors and actuators, Twente

    NARCIS (Netherlands)

    Bergveld, Piet

    1989-01-01

    This paper describes the organization and the research programme of the Sensor and Actuator (S&A) Research Unit of the University of Twente, Enschede, the Netherlands. It includes short descriptions of all present projects concerning: micromachined mechanical sensors and actuators, optical sensors,

  17. Thermal flow micro sensors

    NARCIS (Netherlands)

    Elwenspoek, Michael Curt

    1999-01-01

    A review is given on sensors fabricated by silicon micromachining technology using the thermal domain for the measurement of fluid flow. Attention is paid especially to performance and geometry of the sensors. Three basic types of thermal flow sensors are discussed: anemometers, calorimetric flow

  18. Automotive vehicle sensors

    Energy Technology Data Exchange (ETDEWEB)

    Sheen, S.H.; Raptis, A.C.; Moscynski, M.J.

    1995-09-01

    This report is an introduction to the field of automotive vehicle sensors. It contains a prototype data base for companies working in automotive vehicle sensors, as well as a prototype data base for automotive vehicle sensors. A market analysis is also included.

  19. Extra Sensor Perception

    Directory of Open Access Journals (Sweden)

    Javad MOKHBERY

    2007-01-01

    Full Text Available This article describes the importance of sensor verification. It also describes the benefits of a portable sensor verification system and how it can be an essential tool that compliments any program in which sensors are used for control manufacturing or during critical testing.

  20. An architectural framework for virtual enterprise engineering

    DEFF Research Database (Denmark)

    Zwegers, Arian; Hannus, Matti; Tølle, Martin

    2001-01-01

    , especially concerning integration issues. This paper aims to lay down an architectural framework to support the set-up and operation of virtual enterprises. It supports virtual enterprise engineering. The framework might also be used to identify and position issues that play a role in the set......Enterprises cooperate more extensively with other enterprises during the entire product life cycle. Temporary alliances between various enterprises emerge such as those in virtual enterprises. However, many enterprises experience difficulties in the formation and operation of virtual enterprises......-up and operation of virtual enterprises. As such, it is useful to classify research projects on virtual enterprises as well....