Heterogeneous reconfigurable system for adaptive particle filters in real-time applications

This paper presents a heterogeneous reconfigurable system for real-time applications applying particle filters. The system consists of an FPGA and a multi-threaded CPU. We propose a method to adapt the number of particles dynamically and utilise the run-time reconfigurability of the FPGA for reduced power and energy consumption. An application is developed which involves simultaneous mobile robot localisation and people tracking. It shows that the proposed adaptive particle filter can reduce up to 99% of computation time. Using run-time reconfiguration, we achieve 34% reduction in idle power and save 26-34% of system energy. Our proposed system is up to 7.39 times faster and 3.65 times more energy efficient than the Intel Xeon X5650 CPU with 12 threads, and 1.3 times faster and 2.13 times more energy efficient than an NVIDIA Tesla C2070 GPU. © 2013 Springer-Verlag.

16 chip, 18 Gchips/s walsh-code implementation of an ECDMA access network using two time-shifted FIR filters

We demonstrate for the first time an electronically processed Walsh Code with 16 chips at 18Gchip/s. An auto-cross correlation ratio of 18.1dB is achieved between two orthogonal codes after transmission over 10km of SMF. © 2009 OSA.

Nonconstant quality of auditory filters in the porpoises, Phocoena phocoena and Neophocaena phocaenoides (Cetacea, Phocoenidae)

Simultaneous tone-tone masking in conjunction with the envelope-following response (EFR) recording was used to obtain tuning curves in porpoises Phocoena phocoena and Neophocaena phocaenoides asiaeorientalis. The EFR was evoked by amplitude-modulated probes with a modulation rate of 1000 Hz and carrier frequencies from 22.5 to 140 kHz. Equivalent rectangular quality Q(ERB) of the obtained tuning curves varied from 8.3-8.6 at lower (22.5-32 kHz) probe frequencies to 44.8-47.4 at high (128-140 kHz) frequencies. The QERB dependence on probe frequency could be approximated by regression lines with a slope of 0.83 to 0.86 in log-log scale., which corresponded to almost frequency-proportional quality and almost constant bandwidth of 34 kHz. Thus, the frequency representation in the porpoise auditory system is much closer to a constant-bandwidth rather that to a constant-quality manner. (c) 2006 Acoustical Society of America.

Prediction and suppression of strong dispersive coupling in microracetrack channel drop filters

For a four-port microracetrack channel drop filter, unexpected transmission characteristics due to strong dispersive coupling are demonstrated by the light tunneling between the input-output waveguides and the resonator, where a large dropping transmission at off-resonance wavelengths is observed by finite-difference time-domain simulation. It causes a severe decline of the extinction ratio and finesse. An appropriate decrease of the coupling strength is found to suppress the dispersive coupling and greately increase the extinction ratio and finesse, a decreased coupling strength can be realized by the application of an asymmetrical coupling waveguide structure. In addition, the profile of the coupling dispersion in the transmission spectra can be predicted based on a coupled mode theory analysis of an equivalent system consisting of two coupling straight waveguides. The effects of structure parameters on the transmission spectra obtained by this method agree well with the numerical results. It is useful to avoid the strong dispersive coupling region in the filter design. (c) 2007 Optical Society of America.

Finite-difference time-domain analysis of deformed square cavity filters with a traveling-wave-like filtering response by mode coupling

An add-drop filter based on a perfect square resonator can realize a maximum of only 25% power dropping because the confined modes are standing-wave modes. By means of mode coupling between two modes with inverse symmetry properties, a traveling-wave-like filtering response is obtained in a two-dimensional single square cavity filter with cut or circular corners by finite-difference time-domain simulation. The optimized deformation parameters for an add-drop filter can be accurately predicted as the overlapping point of the two coupling modes in an isolated deformed square cavity. More than 80% power dropping can be obtained in a deformed square cavity filter with a side length of 3.01 mu m. The free spectral region is decided by the mode spacing between modes, with the sum of the mode indices differing by 1. (c) 2007 Optical Society of America.

Distributed mode coupling in microring channel drop filters

The authors present the observation of wide transmission dips in a microring channel drop filter by two-dimensional finite-difference time-domain simulation. The authors show that distributed mode coupling between the input waveguide and the resonator results in the oscillations of the coupling efficiency and the envelope of transmission spectra with wavelength. The critical coupling as the light just passing through the coupling region is important for optimizing related devices. If the width of the input waveguide is different from that of the ring resonator, the phenomenon can be greatly reduced. (c) 2006 American Institute of Physics.

Influence of dispersive coupling coefficient in microring channel drop filters

Wide transmission dips are observed in the through spectra in microring and racetrack channel drop filters by two-dimensional finite-difference time-domain (FDTD) simulation. The transmission spectra, which reflect the coupling efficiency, are also calculated from the FDTD output as the pulse just travels one circle inside the resonator. The results indicate that the dips are caused by the dispersion of the coupling coefficient between the input waveguide and the resonator. In addition, a near-zero channel drop on resonance and a large channel drop off resonance are observed due to the near zero coupling coefficient and a large coupling coefficient, respectively. If the width of the input waveguide is different from that of the ring resonator, the oscillation of the coupling coefficient can be greatly suppressed.

High-Order Microring Filters on SOI Wafer

Submitted by 阎军 (yanj@red.semi.ac.cn) on 2010-06-04T08:05:17Z No. of bitstreams: 1 High-Order Microring Filters on SOI Wafer.pdf: 236326 bytes, checksum: dea85274da2a205a54b8a46049db9c94 (MD5)

Measurement of Be-10 in air filters using BeF- ions from BaBeF4

IEECAS SKLLQG

Color filters with negative birefringence for liquid crystal display use

We have developed a special color film with negative birefringence, which can work as a color filter and a viewing angle extension film for liquid crystal displays (LCDs). A high-performance polyimide (PI), which can be dissolved in the usual organic solvent and shows negative birefringence after lamination, was synthesized to fabricate the film. By mixing PI with suitable proportions of green, blue or red pigment in the solvent, then laminating them onto a glass substrate, we obtained color films with good transmission spectra and suitable chromatic coordinates. The results of our experiments show that the color filters still have negative birefringence but a little lower than that of the pure PI film. and can therefore work as compensation films for normal white twist nematic liquid crystal displays (TN-LCD).

Template Matching: Matched Spatial Filters and Beyond

Template matching by means of cross-correlation is common practice in pattern recognition. However, its sensitivity to deformations of the pattern and the broad and unsharp peaks it produces are significant drawbacks. This paper reviews some results on how these shortcomings can be removed. Several techniques (Matched Spatial Filters, Synthetic Discriminant Functions, Principal Components Projections and Reconstruction Residuals) are reviewed and compared on a common task: locating eyes in a database of faces. New variants are also proposed and compared: least squares Discriminant Functions and the combined use of projections on eigenfunctions and the corresponding reconstruction residuals. Finally, approximation networks are introduced in an attempt to improve filter design by the introduction of nonlinearity.

Coffee Filters and Creativity: The Value of Multiple Filters in the Creative Process

Creativity is often defined as developing something novel or new, that fits its context, and has value. To achieve this, the creative process itself has gained increasing attention as organizational leaders seek competitive advantages through developing new products, services, process, or business models. In this paper, we explore the notion of the creative process as including a series of “filters” or ways to process information as being a critical component of the creative process. We use the metaphor of coffee making and filters because many of our examples come from Vietnam, which is one of the world’s top coffee exporters and which has created a coffee culture rivaling many other countries. We begin with a brief review of the creative process its connection to information processing, propose a tentative framework for integrating the two ideas, and provide examples of how it might work. We close with implications for further practical and theoretical directions for this idea.