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Managing multimedia network services in a User-centric manner provides for more delivered quality to the users, whilst maintaining a limited footprint on the network resources. For efficient User-centric management it is imperative to have a precise metric for perceived quality. Quality of Experience (QoE) is such a metric, which captures many different aspects that compose the perception of quality...
At the National Research Council in Ottawa, the conventional Hysteretic Josephson Array Voltage System (HJVS) and the Programmable Josephson Array Voltage System (PJVS) associated with the watt balance experiment have been directly compared. This direct comparison of Josephson array systems uses an improved automated biasing technique for the hysteretic array. The comparison is being performed with...
Characterizing the dynamics of neural data by a discrete state variable is desirable in experimental analysis and brain-machine interfaces. Previous successes have used dynamical modeling including Hidden Markov Models, but the methods do not always produce meaningful results without being carefully trained or initialized. We propose unsupervised clustering in the spatio-temporal space of neural data...
The design of Brain-Machine Interface (BMI) neural decoders that have robust performance in changing environments encountered in daily life activity is a challenging problem. One solution to this problem is the design of neural decoders that are able to assist and adapt to the user by participating in their perception-action-reward cycle (PARC). Using inspiration both from artificial intelligence...
The activation of neural ensembles in the cortex is correlated with behavioral states and a change in neuronal functional connectivity patterns is expected. In this paper, we investigate this dynamic nature of functional connectivity in the cortex. Because of the time scale of behavior, a robust method with limited sample size is desirable. In light of this, we utilize mean square contingency (MSC)...
One of the important challenges in designing Brain-Machine Interfaces (BMI) is to build implantable systems that have the ability to reliably process the activity of large ensembles of cortical neurons. In this paper, we report the design, fabrication, and testing of a polyimide-based microelectrode array integrated with a low-power amplifier as part of the Florida Wireless Integrated Recording Electrode...
A formulation method is introduced for the symbolic analysis of mixed-mode analog circuits consisting of opamps, current conveyors and/or current-feedback opamps. We show that by modeling all active devices using only nullors and grounded resistors, a reduced system of nodal equations can be formulated and solved by determinant decision diagrams. The nullor equivalents allow including parasitic elements...
This paper presents the application of a reconfigurable impedance tuning network for a mobile DVB-H terminal. These kind of networks are becoming widely used in wireless communication systems to improve its efficiency. On the other hand, antenna design in DVB-H terminals is challenging due to the size limitation and as a result, the antenna presents large mismatches. To address this issue, we propose...
Wireless Mesh Networks (WMNs) are an important networking infrastructure for providing cost-efficient broadband wireless connectivity to a group of users. WMNs are increasingly being used in urban areas, metropolitan and municipal area networks for deployment of medical, transport, surveillance systems, etc. The good performance and operability of WMNs largely depends on placement of mesh routers...
Atrial fibrillation (AF) mechanisms are not completely understood yet. We evaluated the effect of the most useful anaesthetic agent in AF dynamics. Principal component analysis (PCA) has been applied as a method to analyze the variation between the different atrial signals extracted from electrogram. The purpose of PCA as a data decomposition procedure is to study the eigenvalues distribution along...
In this study the effect of the most useful anaesthetic will be evaluated in patients with atrial fibrillation (AF). Principal component analysis (PCA) has been applied as a method to represent the electrogram recordings in a more efficient manner using fewer channels. Subsequently, PCA was applied to reduce the data set to a few representative activations, measured the average dissimilarity between...
With the fast development in wireless technologies and wireless devices, wireless mesh networks (WMN) are becoming and important networking infrastructure, especially due to their low cost of deployment and maintenance. A main issue in deploying WMNs is the optimal placement of mesh routers to achieve network connectivity and stability through the maximization of the size of the giant component in...
Love wave gas sensors with mesoporous thin film as sensitive layers are presented. They are dedicated to volatile organic compound vapor detection. Mesoporous films of SiO2 were prepared using the sol-gel process and deposited on the devices acoustic path. The obtained films have been characterized by ellipsometry resulting in the determination of porosity and pore size distribution in the film and...
A novel extended method to approximate the behavioral model of current-mode analog circuits (CMACs) is presented. The nullor is employed to model the behavior of a MOS transistor (MOST) together with its parasitic elements. In a first part, the signal-path (SP) into a CMAC is approached by using the nullor properties. In the second part, the behavioral model associated to each MOST is generated and...
This paper presents a new design of an automatic impedance synthesizer based on RF switches and its performance. A study about the implementation has been carried out and two prototypes of 50 Omega and 75 Omega of characteristic impedance have been successfully constructed. As switching elements in the tuning network we employ GaAs MMIC RF switches. An evaluation of impedance matching zones in the...
This paper provides a novel configuration to design a multi-scroll chaotic oscillator employing unity-gain cells (UGCs). The inclusion of multi-breakpoints to create a high-order negative nonlinear resistor (NR) is realized by the parallel combinations of basic cells. The breakpoints are controlled with resistors and tuning with level shifters. The multiscroll chaotic attractor has been optimized...
Abnormal adaptation of action potential duration (APD) to changes in heart rate (HR) has been suggested as an indicator of increased arrhythmic risk. In this study, we investigate the mechanisms underlying APD rate adaptation in human atrial cells and its relationship to arrhythmogenesis. Simulations are performed using action potential computational models and results are compared with experimental...
A new implementation of Chua's circuit employing unity-gain cells (UGC) as the active building blocks to emulate the behavior of the nonlinear resistor (NR) and the grounded inductor is introduced. The breakpoints and slopes associated to the NR as well as the numeric value of the inductor can be adjusted by the control resistors. The proposed circuit is suitable for implementation with the commercially...
Soft-core based multiprocessor systems are getting very popular in the FPGA design world. There are many computer architectures that has been used for building multiprocessor systems on FPGAs, including SMP (symmetric multiprocessor). One of the main drawback of this SMP systems is the unavailability of operating systems that allow programming multi-threaded applications that make good use of the...
Conceptualization of the Web as a universal medium for data, information, and knowledge exchange, has drawn attention both of the software engineering and AI communities to semantic service oriented architecture (SOA). One of the challenges of SOA is to deal with service matching which is uncertain and ambiguous. A service requester must be prepared to cope with situations where no required services...
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