Quantification and visualization of uncertainty in cardiac forward and inverse problems with complex geometries is subject to various challenges. Specific to visualization is the observation that occlusion and clutter...
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Quantification and visualization of uncertainty in cardiac forward and inverse problems with complex geometries is subject to various challenges. Specific to visualization is the observation that occlusion and clutter obscure important regions of interest, making visual assessment difficult. In order to overcome these limitations in uncertainty visualization, we have developed and implemented a collection of novel approaches. To highlight the utility of these techniques, we evaluated the uncertainty associated with two examples of modeling myocardial activity. In one case we studied cardiac potentials during the repolarization phase as a function of variability in tissue conductivities of the ischemic heart (forward case). In a second case, we evaluated uncertainty in reconstructed activation times on the epicardium resulting from variation in the control parameter of Tikhonov regularization (inverse case). To overcome difficulties associated with uncertainty visualization, we implemented linked-view windows and interactive animation to the two respective cases. Through dimensionality reduction and superimposed mean and standard deviation measures over time, we were able to display key features in large ensembles of data and highlight regions of interest where larger uncertainties exist.
Single intersection is generally regarded as the elementary unit for solving traffic problem. A Type-2 fuzzy logic controller (T2FLC) for single intersection signal control is presented in this paper as Type-2 fuzzy l...
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Single intersection is generally regarded as the elementary unit for solving traffic problem. A Type-2 fuzzy logic controller (T2FLC) for single intersection signal control is presented in this paper as Type-2 fuzzy logic can handle the imprecision, uncertainties and vagueness lying in the dynamic process more efficiently. Furthermore, the membership function parameters of Type-2 fuzzy logic controller are optimized by genetic algorithm (GA). Simulation experiments are designed to compare the queue length and vehicular average delay of Type-2 fuzzy control optimized by GA with general Type-2 fuzzy control, Type-1 fuzzy control and fixed-time control under various types of vehicle arrival rate. Experimental results indicate that our proposed control method can reduce the queue length and vehicular delay at the intersection effectively and thus demonstrates its superiority.
This paper presents the design and implementation of distributed arithmetic (DA) architectures of three-dimensional (3-D) Discrete Wavelet Transform (DWT) with hybrid method for medical image compression. Due to the s...
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This paper presents the design and implementation of distributed arithmetic (DA) architectures of three-dimensional (3-D) Discrete Wavelet Transform (DWT) with hybrid method for medical image compression. Due to the separability property of the multi-dimensional Haar and Daubechies, the proposed architecture has been implemented using a cascade of three N-point one-dimensional (1-D) Haar/Daubechies and two transpose memories for a 3-D volume of N×N×N, suitable for 3-D medical imaging applications. The architectures were synthesised using VHDL and G-code and implemented on field programmable gate array (FPGA) single board RIO (sbRIO-9632) with Spartan-3 (XC3S2000). Experimental results and an analysis of the area, power consumption, maximum frequency, latency, throughput as well as the subjective test are discussed in this paper.
Orientation estimation is very important for development of unmanned aerial systems (UASs), and is performed by combining data from several sources and sensors. Kalman filters are widely used for this task, however th...
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ISBN:
(纸本)9781479908158
Orientation estimation is very important for development of unmanned aerial systems (UASs), and is performed by combining data from several sources and sensors. Kalman filters are widely used for this task, however they typically assume linearity and Gaussian noise statistics. While these assumptions work well for high-quality, high-cost sensors, it does not work as well for low-cost, low-quality sensors. For low-cost sensors, complementary filters can be used since no assumptions are made with regards to linearity and noise statistics. In this paper, the concepts of filtering based on fractional-order calculus are applied to the complementary filter, and the efficacy of non-integer-order filtering on systems with non-gaussian noise is explored with good success.
Nonhyperbolicity, as characterized by the coexistence of Kolmogorov-Arnold-Moser (KAM) tori and chaos in the phase space, is generic in classical Hamiltonian systems. An open but fundamental question in physics concer...
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Nonhyperbolicity, as characterized by the coexistence of Kolmogorov-Arnold-Moser (KAM) tori and chaos in the phase space, is generic in classical Hamiltonian systems. An open but fundamental question in physics concerns the relativistic quantum manifestations of nonhyperbolic dynamics. We choose the mushroom billiard that has been mathematically proven to be nonhyperbolic, and study the resonant tunneling dynamics of a massless Dirac fermion. We find that the tunneling rate as a function of the energy exhibits a striking “clustering” phenomenon, where the majority of the values of the rate concentrate on a narrow region, as a result of the chaos component in the classical phase space. Relatively few values of the tunneling rate, however, spread outside the clustering region due to the integrable component. Resonant tunneling of electrons in nonhyperbolic chaotic graphene systems exhibits a similar behavior. To understand these numerical results, we develop a theoretical framework by combining analytic solutions of the Dirac equation in certain integrable domains and physical intuitions gained from current understanding of the quantum manifestations of chaos. In particular, we employ a theoretical formalism based on the concept of self-energies to calculate the tunneling rate and analytically solve the Dirac equation in one dimension as well as in two dimensions for a circular-ring-type of tunneling systems exhibiting integrable dynamics in the classical limit. Because relatively few and distinct classical periodic orbits are present in the integrable component, the corresponding relativistic quantum states can have drastically different behaviors, leading to a wide spread in the values of the tunneling rate in the energy-rate plane. In contrast, the chaotic component has embedded within itself an infinite number of unstable periodic orbits, which provide far more quantum states for tunneling. Due to the nature of chaos, these states are characteristically similar, l
In this paper, we propose a new intelligent, robust and adaptive digital watermarking technique for colour images based on the combination of discrete wavelet transform (DWT), human visual system (HVS) model and gener...
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This paper presents specially designed tests performed in a cryptosystem based on chaotic continuous cellular automata (CCA). The degree of the cryptosystem security is evaluated by taking two approaches: (i) stationa...
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Secure and efficient management of multimedia objects in medical information system have become a necessity in today's global environment. To strengthen the security level already present in the database managemen...
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The 6th International Conference on Surface Plasmon Photonics (SPP6) was held in Ottawa, Canada from May 26th to 31st, 2013. This independent series of biennial conferences is widely regarded as the premier series in ...
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