Sensorimotor synchronisation

Timing abilities are often measured by having participants tap their finger along with a metronome and presenting tap-triggered auditory feedback. These experiments predominantly use electronic percussion pads combined with software (e.g., FTAP or Max/MSP) that records responses and delivers auditory feedback. However, these setups involve unknown latencies between tap onset and auditory feedback and can sometimes miss responses or record multiple, superfluous responses for a single tap. These issues may distort measurements of tapping performance or affect the performance of the individual. We present an alternative setup using an Arduino microcontroller that addresses these issues and delivers low-latency auditory feedback. We validated our setup by having participants (N = 6) tap on a force-sensitive resistor pad connected to the Arduino and on an electronic percussion pad with various levels of force and tempi. The Arduino delivered auditory feedback through a pulse-width modula...

This paper deals with iterative maximum-likelihood synchronization of a scalar parameter. An efficient implementation of the Newton-Raphson (NR) maximum-search method is proposed. Considering the latter implementation, the NR approach is shown to be an attractive alternative to synchronization methods based on the expectation-maximization (EM) algorithm. Simulation results for the case of phase-offset synchronization show that NR method usually increases the speed of convergence of the synchronization algorithm.

Observation of human-induced large-amplitude lateral vibration of an actual pedestrian bridge in an extremely congested condition is reported. Walking motions of pedestrians recorded by a video camera are analysed. It is found that walking among 20 per cent or more of the pedestrians on the bridge was synchronized to the girder lateral vibration. With this synchronization, the total lateral force from the pedestrians to the girder is evidently increased and it acts as a resonant force on the girder lateral vibration. 1 Hz [Figure l(b)]. The magnitude of the lateral force from human walk, however, is smaller by one order than the vertical force, as shown in Figure 1(b)2. Nevertheless, it should be noted that human-induced lateral 1.5-2.3 Hz.

We present a solution to the Firing Squad Synchronization Problem that works both in Von Neumann and Moore neighborhood and whatever is the dimension of the space. That solution is based on fields that provide a clean modular decomposition of such cellular automata problem.

This paper discusses about design of common wireless communication services recognition for three different standards, i.e. Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS) or Wideband Code division Access (WCDMA), and Long Term Evolution (LTE), also known well as 2G, 3G, and 3.9G respectively. To recognize them using a common system, we propose performing within synchronization channel detection since the similarity in cell search procedures i.e. always detect synchronization signals. To minimize resources, we prefer using autocorrelation to detect GSM and LTE synchronization signals and match filter for UMTS synchronization signal. However, it is not enough to distinguish each others. Therefore, we also propose to recognize the peak period of the autocorrelation output as a main concept to distinguish the standards. We design this system using symplify DSP tool and simulate in simulink. The simulations are performed within AWGN channel and show good performance even with 10 dB SNR. Moreover, FPGA implementation for target device Virtex 4 XC4VLX200, the proposed design can be implemented within 24171 look up tables (LUTs).

This article examines how Modern theories of mind remain even in some materialistic and hence ontologically anti-dualistic views; and shows how Dewey, anticipating Merleau-Ponty and 4E cognitive scientists, repudiates these theories. Throughout I place Dewey’s thought in the context of scientific inquiry, both recent and historical and including the cognitive as well as traditional sciences; and I show how he incorporated sciences of his day into his thought, while also anticipating enactive cognitive science. While emphasizing Dewey’s continued relevance, my main goal is to show how his scientifically informed account of perception and cognition combats skepticism propagated by certain scientific visions, exacerbated by commonplace notions about mind, that jointly suggest that human beings lack genuine access to reality.

The use of networks for communications between the electronic control units (ECU) of a vehicle in production cars dates from the beginning of the 1990s. The specific requirements of the different car domains have led to the development of a large number of automotive networks such as Local Interconnect Network, J1850, CAN, TTP/C, FlexRay, media-oriented system transport, IDB1394, etc. This paper first introduces the context of in-vehicle embedded systems and, in particular, the requirements imposed on the communication systems. Then, a comprehensive review of the most widely used automotive networks, as well as the emerging ones, is given. Next, the current efforts of the automotive industry on middleware technologies, which may be of great help in mastering the heterogeneity, are reviewed. Finally, we highlight future trends in the development of automotive communication systems.

ltra-wideband (UWB) radio is a fast emerging technology with uniquely attractive features inviting major advances in wireless communications, networking, radar, imaging, and positioning systems. By its rulemaking proposal in 2002, the Federal Communications Commission (FCC) in the United States essentially unleashed huge "new bandwidth'' (3.6-10.1 GHz) at the noise floor, where UWB radios overlaying coexistent RF systems can operate using low-power ultra-short information bearing pulses. With similar regulatory processes currently under way in many countries worldwide, industry, government agencies, and academic institutions responded to this FCC ruling with rapidly growing research efforts targeting a host of exciting UWB applications: short-range very high-speed broadband access to the Internet, covert communication links, localization at centimeter-level accuracy, high-resolution ground-penetrating radar, through-wall imaging, precision navigation and asset tracking, just to name a few. This tutorial focuses on UWB wireless communications at the physical layer. It overviews the state-of-the-art in channel modeling, transmitters, and receivers of UWB radios, and outlines research directions and challenges to be overcome. As signal processing expertise is expected to have major impact in research and development of UWB systems, emphasis is placed on DSP aspects.

This paper presents a grid-connected photovoltaic (PV) system with a three level voltage source converter (VSC) using double closed loop control strategy. The outer DC voltage control loop is to regulate the DC bus voltage, and the inner current control loop is to synchronize the output current with the grid voltage, thus ensuring unity power factor. A LLC resonant DC-DC converter is used in the proposed system to step-up the voltage of the PV array and to extract maximum power. It is intrinsically isolated by a high frequency transformer, then the parasitic capacitance of the PV panels to ground could not be of concern; furthermore, because of soft switching technique, it operates at high frequency with low switching losses. Size and cost of the magnetic components and DC-link capacitor are decreased compared with traditional boost converters. An incremental conductance method integrated within PI controller was used to extract maximum power by PV. Simulation results based on MATLAB/Simulink verify the validity and dynamic performance of the proposed system during fast solar irradiation changes and ensure DC bus voltage stability.

Clock distribution networks synchronize the flow of data signals among synchronous data paths. The design of these networks can dramatically affect system-wide performance and reliability. A theoretical background of clock skew is provided in order to better understand how clock distribution networks interact with data paths. Minimum and maximum timing constraints are developed from the relative timing between the localized clock skew and the data paths. These constraint relationships are reviewed, and compensating design techniques are discussed.

This paper analyzes a methodology to evaluate the efficiency of different network configurations and associated planning parameters for delivering DVB-T2 services to fixed and portable receivers, based on theoretical SFN networks. The impact of some of the parameters and calculation algorithms on the final coverage percentage values for different SFN network architectures has been studied from simulations. The results have shown that the synchronization strategy and the signal combination method have a relevant impact on the final coverage percents within the service area both for portable and fixed reception.

Quantum memory is important to quantum information processing in many ways: a synchronization device to match various processes within a quantum computer, an identity quantum gate that leaves any state unchanged, and a tool to convert heralded photons to photons-on-demand. In addition to quantum computing, quantum memory would be instrumental for the implementation of long-distance quantum communication using quantum repeaters. The importance of this basic quantum gate is exemplified by the multitude of optical quantum memory mechanisms being studied: optical delay lines, cavities, electromagnetically-induced transparency, photon-echo, and off-resonant Faraday interaction. Here we report on the state-of-the-art in the field of optical quantum memory, including criteria for successful quantum memory and current performance levels.

In this paper, an extension to the SpaceWire standard [1] is presented which increases considerably its synchronization capability. Initially developed in the scope of Simbol-X [2], a CNES formation flying instrument where time-tagging of data science from three detectors is critical to perform on-board processing, the extension can be implemented in all equipments where the use of the performing SpaceWire standard is not possible due to its intrinsic synchronization limitation. This limitation gives a lack of precision ten times the data transmission period rate plus two periods of the receiver synchronization clock. With the additional feature this uncertainty is reduced to two periods of the receiver synchronization clock. The extension takes advantage of already existing capabilities of the SpaceWire standard with no impact on the data layer and very limited additional resource needs. The resulting performances measured on a prototype are presented still in the framework of the Simbol-X instrument using ACTEL space qualified FPGA as target.

Although several techniques have been developed for the visualization of EEG event-related desynchronization/synchronization (ERD/ERS) in both time and frequency domains, none of the quantification methods takes advantage of the time and frequency resolution at the same time. Existing techniques for the quantification of the ERD/ERS changes compute the average EEG power increase/decrease relative to certain reference value, over fixed time intervals and/or frequency bands (either fixed or individualized). Inaccuracy in the computation of these frequency bands (where the process is actually measured) in combination with the averaging process over time may lead to errors in the computation of any ERD/ERS quantification parameter. In this paper, we present a novel method for the automatic, individual and exact quantification of the most significant ERD/ERS region within a given window of the time-frequency domain. The method is exemplified by quantifying the ERS at low frequencies of 1...

Near Future on-board Telemetry, Tracking and Command (TT&C) equipment for secure communications will likely adopt Frequency Hopping (FH) instead of Direct Sequence (DS) Spread Spectrum (SS) techniques. As far as TT&C systems will have to cope with jammer-to-signal power ratios higher than 50 dB, classical DS approaches must be abandoned in favour of more robust FH solutions. In the following paper we present an overview of synchronization, channel coding and modulation issues for next generation anti-jamming TT&C transponder under study and design at Alcatel Alenia Space -Italy (AAS-I).

This study tested the two following hypotheses: (i) compared with non-athletes, elite athletes are characterized by a reduced cortical activation during the preparation of precise visuo-motor performance; (ii) in elite athletes, an optimal visuo-motor performance is related to a low cortical activation. To this aim, electroencephalographic (EEG; 56 channels; Be Plus EB-Neuro) data were recorded in 18 right-handed elite air pistol shooters and 10 right-handed non-athletes. All subjects performed 120 shots. The EEG data were spatially enhanced by surface Laplacian estimation. With reference to a baseline period, power decrease/increase of alpha rhythms during the preshot period indexed the cortical activation/deactivation (event-related desynchronization/synchronization, ERD/ERS). Regarding the hypothesis (i), low-(about 8-10 Hz) and high-frequency (about 10-12 Hz) alpha ERD was lower in amplitude in the elite athletes than in the non-athletes over the whole scalp. Regarding the hypothesis (ii), the elite athletes showed high-frequency alpha ERS (about 10-12 Hz) larger in amplitude for high score shots (50%) than for low score shots; this was true in right parietal and left central areas. A control analysis confirmed these results with another indicator of cortical activation (beta ERD, about 20 Hz). The control analysis also showed that the amplitude reduction of alpha ERD for the high compared with low score shots was not observed in the non-athletes. The present findings globally suggest in Wiley InterScience (www.

We report about the first X-band spaceborneairborne bistatic synthetic aperture radar (SAR) experiment, conducted early November 2007, using the German satellite TerraSAR-X as transmitter and the German Aerospace Center's (DLR) new airborne radar system F-SAR as receiver. The importance of the experiment resides in both its pioneering character and its potential to serve as a test bed for the validation of nonstationary bistatic acquisitions, novel calibration and synchronization algorithms, and advanced imaging techniques. Due to the independent operation of the transmitter and receiver, an accurate synchronization procedure was needed during processing to make high-resolution imaging feasible. Precise phase-preserving bistatic focusing can only be achieved if time and phase synchronization exist. The synchronization approach, based on the evaluation of the range histories of several reference targets, was verified through a separate analysis of the range and Doppler contributions. After successful synchronization, nonstationary focusing was performed using a bistatic backprojection algorithm. During the campaign, stand-alone TerraSAR-X monostatic as well as interoperated TerraSAR-X/F-SAR bistatic data sets were recorded. As expected, the bistatic image shows a space-variant behavior in spatial resolution and in signal-to-noise ratio. Due to the selected configuration, the bistatic image outperforms its monostatic counterpart in almost the complete imaged scene. A detailed comparison between monostatic and bistatic images is given, illustrating the complementarity of both measurements in terms of backscatter and Doppler information. The results are of fundamental importance for the development of future nonsynchronized bistatic SAR systems.

The current paper addresses the issue of estimating the sampling instant in turbo receivers. The proposed synchronizer is based on the expectation-maximization (EM) algorithm and takes benefit from the soft information delivered by the turbo system. Performance of the proposed synchronizer is illustrated by simulation results. In particular, the mean and the variance of the estimator as well as the bit error rate reached by the synchronized system are reported.

Conventional vibration signal processing techniques are most suitable for stationary processes. However, most mechanical faults in machinery reveal themselves through transient events in vibration signals. Timeseries modelling, including autoregressive moving average (ARMA) modelling and autoregressive (AR) modelling, is an efficient approach for transient signal analysis. Based on the adaptive prediction technique, this paper applies the principle of the adaptive line enhancer (ALE) to the modelling of transient vibration signals. The time-series models, adaptive algorithms and the rational time-frequency transfer function are investigated in the paper. Simulation and experimental studies with different time-frequency-amplitude distributions and transient vibration responses are described. The results show that the adaptive modelling method can trace the time-frequency signal and extract dynamic features such as time-frequency distributions and time-amplitude distributions from sample signals. Given the simple programming and potentially easy implementation in on-line applications, this method should have application in machine monitoring and fault diagnosis. r

Advances in image sensors and evolution of digital computation is a strong stimulus for development and implementation of sophisticated methods for capturing, processing and analysis of 3-D data from dynamic scenes. Research on perspective time-varying 3-D scene capture technologies is important for the upcoming 3DTV displays. Methods such as shape-from-texture, shape-from-shading, shape-from-focus, and shape-from-motion extraction can restore 3-D shape information from a single camera data. The existing techniques for 3-D extraction from single-camera video sequences are especially useful for conversion of the already available vast mono-view content to the 3DTV systems. Sceneoriented single-camera methods such as human face reconstruction and facial motion analysis, body modeling and body motion tracking, and motion recognition solve efficiently a variety of tasks. 3-D multicamera dynamic acquisition and reconstruction, their hardware specifics including calibration and synchronization and software demands form another area of intensive research. Different classes of multiview stereo algorithms such as those based on cost function computing and optimization, fusing of multiple views, and feature-point reconstruction are possible candidates for dynamic 3-D reconstruction. High-resolution digital holography and pattern projection techniques such as coded light or fringe projection for real-time extraction of 3-D object positions and color information could manifest themselves as an alternative to traditional camera-based methods. Apart from all of these approaches, there also are some active imaging devices capable of 3-D extraction such as the 3-D time-of-flight camera, which provides 3-D image data of its environment by means of a modulated infrared light source.

Power quality instrumentation requires accurate fundamental frequency estimation and signal synchronization, even in the presence of both stationary and transient disturbances. In this paper, the authors present a synchronization technique for power quality instruments based on a single-phase software phase-locked loop (PLL), which is able to perform the synchronization, even in the presence of such disturbances. Moreover, PLL is able to detect the occurrence of a transient disturbance.

The use of networks for communications between the electronic control units (ECU) of a vehicle in production cars dates from the beginning of the 1990s. The specific requirements of the different car domains have led to the development of a large number of automotive networks such as Local Interconnect Network, J1850, CAN, TTP/C, FlexRay, media-oriented system transport, IDB1394, etc. This paper first introduces the context of in-vehicle embedded systems and, in particular, the requirements imposed on the communication systems. Then, a comprehensive review of the most widely used automotive networks, as well as the emerging ones, is given. Next, the current efforts of the automotive industry on middleware technologies, which may be of great help in mastering the heterogeneity, are reviewed. Finally, we highlight future trends in the development of automotive communication systems.

Control Systems (WAMC) are becoming a reality with increased international research and development. Several monitoring and control applications based on these systems have been proposed, and although with a relative small adoption, they are currently supporting the operations of some large transmission system operators. It is expected that the continued research and development of phasor data applications will enable the miracle of "Smart Grids" at the transmission level. The authors have realized that this can be achieved in timely fashion only if a research and development platform is developed to simultaneously address issues regarding information and communication infrastructures, and phasor data applications. This paper discusses the preliminary development, and deployment of an experimental wide-area monitoring and control platform in which several basic applications have been implemented, and that in the future will allow for the implementation and testing of envisioned applications. At its current stage, the platform allows both online monitoring and off-line analysis. In the future, it will be the cornerstone to a wider platform enabling research on phasor data applications that intrinsically account for ICT aspects.

This paper proposes an effective barrier synchronization implementations for shared memory-based parallel programming models (e.g. OpenMP) on the Intel SCC non-cachecoherent platform. Barrier synchronization primitives are key components of these programming models to coordinate the parallel threads. Therefore, we need an efficient implementation of the underlying synchronization algorithms to allow high-level barrier constructs for better performance. In particular, we present an efficient evaluation method to determine the overhead associated with integration of barrier algorithms that is required for OpenMP runtime libraries. We validate several implementation variants that efficiently use the network topology and SCCspecific hardware. Our experimental results for different Microbenchmarks show significant performance improvement up to 98% for 48 cores.

At the core of the development of "Smart Transmission Grids" is the design, implementation, and testing of synchronized phasor measurement data applications that can supplement Wide-Area Monitoring, Protection, and Control Systems (WAMPAC). Nevertheless, the development of new PMU data-based WAMPAC applications has been relatively slow. The great potential of WAMPAC systems is being limited by this, and efforts are needed so that new applications can be developed. The slow rate of development of these applications is strongly related to, among other factors, the application development approach used. This article starts by discussing the needs and approaches for developing WAMPAC applications that exploit synchronized phasor measurements, and illustrates how one of these approaches has been achieved. A preliminary work carried out to develop and implement a Smart Transmission System Laboratory (SmarTS Lab), a hardware and softwarebased system for developing and analyzing "Smart Transmission Grids" paradigms and applications for WAMPAC systems, are described. The laboratory's conceptual architecture and hardware and software implementation are presented, and some of its components are described. Finally, the article illustrates proofof-concept examples of how PMU data-based applications can be developed.

The purpose of this study was to evaluate the effects of a Greek traditional dance programme on sensorimotor synchronization (SMS) and reaction time on primary school children (6.41 ± .41 yr.). We randomly assigned 61 children to either the dance group (31 children, 15 boys, 16 girls, 6.42 ± .40 yr.), who took part in a dance programme of 12 lessons (3 times/week), or the control group (30 children, 16 boys, 14 girls, 6.40 ± .42 yr.). Before and after the intervention, we assessed both groups for SMS (walking in synchrony to 80 and 120 beats/min) and reaction time. Two-way ANOVA repeated measures show that the dance group performed significantly better on SMS compared to the control group at 80 beats/min (BPM), but not at 120 BPM. We discuss the results in relation to spontaneous motor tempo and the information-processing theory. In relation to reaction time, no significant difference was observed between the two groups at the end of the intervention. However, the dance group showed a significant improvement between pre-and post-tests. It may be concluded that a dance programme of 12 lessons constitutes an effective and enjoyable activity for the improvement of young children's sensorimotor synchronization at 80 BPM and perhaps reaction time.

than those who did not enjoy dancing. While for all participants hand movements accelerated more and were more complex, torso movements were more synchronised to the beat. Overall, movements were mostly synchronised to the main beat and half-beat level, depending on the body-part. We demonstrate that while people do not move or synchronise much to rhythms with high syncopation when dancing spontaneously to music, the relationship between rhythmic complexity and synchronisation is less linear than in simple finger-tapping studies.

This paper addresses an unbiased p-step predictive finite impulse response (FIR) filter of the local clock K-degree time interval error (TIE) polynomial model with applications to the Global Positioning System (GPS)-based clock synchronization. Generic coefficients are derived for a two-parameter family of the polynomial filter gains. A generalization is provided for the p-step linear (ramp) gain allowing for close to optimal predictive filtering of the TIE. Basic holdover algorithms are discussed along with their most critical properties. Efficiency of the proposed filter in holdover is demonstrated by simulation and in real applications to GPS-based (sawtooth and sawtooth-less) measurements of the TIE of a crystal clock.

Sensor nodes are small-size, low-cost embedded systems capable of local processing and RF communication. In a sensor network, nodes need to organize their operations to perform distributed sensing tasks, and need therefore to be time synchronized to a common reference. In this paper we present a time-synchronization approach for Wireless Sensor Networks (WSNs), denoted as Accuracy-Driven Synchronization Protocol (ADSP). ADSP is based on the "always-on" model of time synchronization, and offers customizable accuracy level, using a novel method to reduce the transmit-to-receive time delay. The time reference is provided by a master node frequently broadcasting packets that the nodes use to synchronize themselves, and then to improve their synchronization. Nodes estimate their own clock characteristics with respect to the master node, thus keeping themselves synchronized even when the master node is not transmitting. The one-way broadcast scheme adopted by ADSP guarantees extremely low energy consumption.

This paper concentrates on transparency and synchronization of supermedia in Internet based teleoperation. Supermedia is used to describe the collection of all the feedback streams in teleoperations, such as haptic, video, audio, temperature and others. Transparency and synchronization are introduced and analyzed from the event-based control perspective. The concepts of event-transparency and event-synchronization for event-based control telerobotic systems are developed and their implications are studied. To illustrate those concepts and their benefits, the teleoperation of a mobile manipulator via the Internet, where haptic, video and temperature information is fed back to the operator, is discussed. Experimental results will verify the event-transparency and event-synchronization of this event-based telerobotic system. 2713 0-7803-7272-7/02/$17.00

I n our society, people make presentations to inform, teach, motivate, and persuade others. Appropriate gestures effectively enhance the expressiveness and believability of such presentations. Likewise, a virtual human agent who adequately performs gestures during presentations can inform us effectively and serve as an interface agent mediating communication between user and computer.

As digital television matures, applications which utilize data embedded in the broadcast television signal are likely to be an important feature of the new medium. This paper explores some of the issues involved in the implementation of systems for the utilization of data which accompanies digital television's video and audio content. Chief among these issues are those which pertain to:

The latest research works on the synchronization scheme for either continuous transmission mode or burst packet transmission mode for the wireless OFDM communications are overviewed in this paper. The typical algorithms dealing with the symbol timing synchronization, the carrier frequency synchronization as well as the sampling clock synchronization are briefly introduced and analyzed. Three improved methods for the fine symbol timing synchronization in frequency domain are also proposed, with several key issues on the synchronization for the OFDM systems discussed.

User privacy is a notable security issue in wireless communications. It concerns about user identities from being exposed and user movements and whereabouts from being tracked. The concern of user privacy is particularly signified in systems which support roaming when users are able to hop across networks administered by different operators. In this paper, we propose a novel construction approach of anonymous and authenticated key exchange protocols for a roaming user and a visiting server to establish a random session key in such a way that the visiting server authenticates the user's home server without knowing exactly who the user is. A network eavesdropper cannot find out the user's identity either (user anonymity). In addition, visited servers cannot track the roaming user's movements and whereabouts even they collude with each other (user untraceability). Our construction approach is generic and built upon provably secure two-party key establishment protocols. Merits of our generic protocol construction include eliminating alias synchronization between the user and the home server, supporting joint key control, and not relying on any special security assumptions on the communication channel between the visiting server and the user's home server. Our protocol can also be implemented efficiently. By piggybacking some message flows, the number of message flows between the roaming user and the visiting server is only three. As of independent interest, we describe a new practical attack called deposit-case attack and show that some previously proposed protocols are vulnerable to this attack.

journal hom epage: www.elsevier.com/locate/humov compared with the case where normal vision and sound were restricted between participants. Discussion: These data suggest that unintentional gait entrainment can be reproduced in a laboratory setting using side by side treadmills, and that anthropometric properties, such as leg length, have a significant effect on gait synchronization. Further, alterations in sensory information can affect unintentional, interpersonal synchronization, but this behavior appears to be relatively robust to changes in sensory feedback pathways related to gait.

Abstract—We study the problem of landmark selection for landmark-based routing in a network of fixed wireless com-munication nodes. We present a distributed landmark selection algorithm that does not rely on global clock synchronization, and a companion local greedy ...

Wireless Sensor Networks (WSNs) can take advantage of versatility, completeness, and low prices of standard wireless protocols; Bluetooth as we will show later is a candidate suitable for WSNs. The fusion of data collected over a WSN is just an evident application of time synchronization. Bringing together these two issues, we find that synchronization using standard protocols poses an important drawback. In this paper, we present a simple method that allows clock synchronization in Bluetooth WSNs, down to few microseconds.