Now showing 1 - 10 of 91
  • Publication
    Wearable Absolute 6 DOF Exercise Training System for Post Stroke Rehabilitation
    (Dublin City University, 2010-09-02) ; ;
    This paper introduces a multidisciplinary research effort to design an interactive, real time system to assist rehabilitation of stroke patients. The proposed system aims to help stroke survivors with limited mobility to relearn lost skills and regain maximal functional independence. The system assesses the quality of exercise being performed and provides advisory feedback to the patient in order to enable task specific training and correct motor relearning. The system uses a novel, ambulatory and wearable 6 Degree of Freedom (DOF) motion capture system composed of miniature ultrasonic and inertial sensors. The system captures the 3D kinematic parameters of the subject¿s movement while performing exercise, enabling tele-medicine applications or subsequent review by clinical experts. The paper presents the architecture of the aforementioned system and results from early stages of the research.
  • Publication
    Adapting and Parameterising Auditory Icons for use in a Synthetic Musical Instrument
    (The Institution of Engineering and Technology., 2009-06-10) ; ;
    In this paper we describe the adaptation and parameterization of environmental auditory event structures for use in a real-time musical synthesizer. In doing so, we have developed a new software musical instrument based on the parametric representation of ecological sound structures, and which facilitates the application of typically non-musical auditory events in a musical context. Since this approach is to be realised within a low-latency, performance oriented synthesizer, our aim is not the development of computationally expensive physical models, but rather to effectively convey complex auditory events using arrays of simple sinusoidal components, while still retaining the key perceptual features of those events. By offering a performer ecologically-derived parameter control, we aim to encourage an Everyday Listening approach to electronic music performance, while also allowing the user to combine and develop typically unrelated elements of environmental auditory events.
  • Publication
    Fast Mode Decision With Early Termination For H.264/AVC Video Coding
    (The Institute of Engineering and Technology (IET), 2006-10-28) ;
    In this paper a fast mode decision algorithm based on an early termination procedure is proposed for H.264/AVC video encoding. Unlike previous methods, the termination decision is based on the rate distortion cost function. A statistical analysis of the spatio-temporal characteristics of the rate distortion cost function and of the probability of mode transition is given for test sequences. Experimental results show that the new algorithm provides a 38% reduction in total computational complexity with a negligible increase in the bit rate and negligible reduction in visual quality when compared to conventional encoding.
  • Publication
    DOA Estimation for a Multi-Frequency Signal Using widely-spaced Sensors
    The estimation of sub-sample time-delay from the phase of the cross-power spectrum (CPS) of signals received by widely-spaced receivers requires unwrapped phase. Conventional phase unwrapping methods require a continuous CPS that starts at zero frequency or at a frequency with a known unwrapped phase. A novel phase unwrapping method is proposed herein that is capable of carrying out the task without these requirements. The proposed method is applied to direction-of-arrival (DOA) estimation for a bandpass signal—a case that conventional methods are unable to handle. Analytical performance and experimental results confirm the effectiveness of the proposed method.
  • Publication
    Dynamic Current Modelling at the Instruction Level
    Estimation of processor current consumption is important for the design of low power systems. This paper proposes a novel method for estimating the dynamic current consumption of a processor. The method models dynamic current as the output of a linear system excited by a signal comprised of the total current due to each instruction. System identification is performed by cross-correlation of a pseudo-random stimulus with the measured current. The method was applied to the Texas Instruments TMS320VC5510 DSP and was found to provide an average correlation of 93% between estimated and measured dynamic current across a range of benchmarks.
  • Publication
    Open Source Dataset and Deep Learning Models for Online Digit Gesture Recognition on Touchscreens
    (The Irish Pattern Recognition & Classification Society, 2017-09-01) ; ;
    This paper presents an evaluation of deep neural networks for recognition of digits entered by users on a smartphone touchscreen. A new large dataset of Arabic numerals was collected for training and evaluation of the network. The dataset consists of spatial and temporal touch data recorded for 80 digits entered by 260 users. Two neural network models were investigated. The first model was a 2D convolutional neural (ConvNet) network applied to bitmaps of the glpyhs created by interpolation of the sensed screen touches and its topology is similar to that of previously published models for offline handwriting recognition from scanned images. The second model used a 1D ConvNet architecture but was applied to the sequence of polar vectors connecting the touch points. The models were found to provide accuracies of 98.50% and 95.86%, respectively. The second model was much simpler, providing a reduction in the number of parameters from 1,663,370 to 287,690. The dataset has been made available to the community as an open source resource.
  • Publication
    Non-Line of Sight Mitigation using a Measurement and Positioning Filtering Algorithm
    In recent years, research interest in location systems has increased due to the emergence of mobile computing devices and the promise of Ubiquitous Computing. This paper considers the problem arising in ultrasonic location systems of Non-Line of Sight (NLOS) between Base Stations and Mobile Devices, which can give significant location errors. Herein, a Dual Kalman Filtering method is proposed to mitigate NLOS effects, using an a-priori partial knowledge of the ultrasonic signals. The main advantage of this method is that the first filter provides a set of filtered ranges that mitigates the NLOS ranging error, while the second filter, by taking these measurements, provides a second positioning filtering that mitigates the overall positioning error. The method is shown to reduce location errors providing a maximum error in location of 9cm.
  • Publication
    A DSP Coprocessor for ADSL Lite
    This paper presents Massana's DSP co-processor solution – FILU-DMT [1] for enabling soft G.Lite (or ADSL Lite) on Pentium and RISC processors. The user interacts with the coprocessor via a C API which accesses a shared RAM interface. All of the G.Lite DSP functions are pre-programmed and held in ROM. The FILU-DMT is implemented in fully synthesizable Verilog RTL with a single synchronous clock for high scan coverage. It is based on a dual MAC architecture which can perform a radix-4 FFT butterfly in 8 cycles yielding a 256 point FFT in 21 µs. This is the industry's fastest FFT for this class of processor. The FILU-DMT supports block floating-point arithmetic which achieves near floating-point performance at a fraction of the area cost of conventional DSPs.
  • Publication
    Postural control strategies during single limb stance following acute lateral ankle sprain
    Single-limb stance is maintained via the integration of visual, vestibular and somatosensory afferents. Musculoskeletal injury challenges the somatosensory system to reweight distorted sensory afferents. This investigation supplements kinetic analysis of eyes-open and eyes-closed single-limb stance tasks with a kinematic profile of lower limb postural orientation in an acute lateral ankle sprain group to assess the adaptive capacity of the sensorimotor system to injury. Sixty-six participants with first-time acute lateral ankle sprain completed a 20-second eyes-open single-limb stance task on their injured and non-injured limbs (task 1). Twenty-three of these participants successfully completed the same 20-second single-limb stance task with their eyes closed (task 2). A non-injured control group of 19 participants completed task 1, with 16 completing task 2. 3-dimensional kinematics of the hip, knee and ankle joints, as well as associated fractal dimension of the center-of-pressure path were determined for each limb during these tasks. Between trial analyses revealed significant differences in stance limb kinematics and fractal dimension of the center-of-pressure path for task 2 only. The control group bilaterally assumed a position of greater hip flexion compared to injured participants on their side-matched “involved”(7.41 [6.1°] vs 1.44 [4.8]°; η2 = .34) and “uninvolved” (9.59 [8.5°] vs 2.16 [5.6°]; η2 = .31) limbs, with a greater fractal dimension of the center-of-pressure path (involved limb = 1.39 [0.16°] vs 1.25 [0.14°]; uninvolved limb = 1.37 [0.21°] vs 1.23 [0.14°]). Bilateral impairment in postural control strategies present following a first time acute lateral ankle sprain.
      804Scopus© Citations 40
  • Publication
    Low Cost, Wideband Ultrasonic Transmitter and Receiver for Array Signal Processing Applications
    This paper presents a low-cost, wideband ultrasonic transmitter for in-air ultrasonic applications based on a conventional narrowband piezoceramic transducer with a LR circuit modification. An analytic method for calculation of the optimum circuit parameters for bandwidth expansion of the ceramic ultrasonic transmitter is described, together with experimental data proving the viability of the method. A low cost wideband ultrasonic receiver array is also presented. The results of the first characterization of MEMs microphones in the ultrasonic band and their use in a sensor array for ultrasonic Array Signal Processing applications is presented. The study presents examples of prototype performance in ultrasonic indoor applications.
      2761Scopus© Citations 20