Implementation of RNS-Based Distributed Arithmetic Discrete Wavelet Transform Architectures Using Field-Programmable Logic

Currently there are design barriers inhibiting the implementation of high-precision digital signal processing (DSP) objects with field programmable logic (FPL) devices. This paper explores overcoming these barriers by fusing together the popular distributed arithmetic (DA) method with the residue number system (RNS) for use in FPL-centric designs. The new design paradigm is studied in the context of a high-performance filter bank and a discrete wavelet transform (DWT). The proposed design paradigm is facilitated by a new RNS accumulator structure based on a carry save adder (CSA). The reported methodology also introduces a polyphase filter structure that results in a reduced look-up table (LUT) budget. The 2C-DA and RNS-DA are compared, in the context of a FPL implementation strategy, using a discrete wavelet transform (DWT) filter bank as a common design theme. The results show that the RNS-DA, compared to a traditional 2C-DA design, enjoys a performance advantage that increases with precision (wordlength).     

Power Distribution Fault Cause Identification With Imbalanced Data Using the Data Mining-Based Fuzzy Classification E-Algorithm

Power distribution systems have been significantly affected by many outage-causing events. Good fault cause identification can help expedite the restoration procedure and improve the system reliability. However, the data imbalance issue in many real-world data sets often degrades the fault cause identification performance. In this paper, the E-algorithm, which is extended from the fuzzy classification algorithm by Ishibuchi to alleviate the effect of imbalanced data constitution, is applied to Duke Energy outage data for distribution fault cause identification. Three major outage causes (tree, animal, and lightning) are used as prototypes. The performance of E-algorithm on real-world imbalanced data is compared with artificial neural network. The results show that the E-algorithm can greatly improve the performance when the data are imbalanced     

Design and evaluation of an optically triggered monolithic sampleand hold circuit using GaAs MESFET technology

The design and evaluation of an optically triggered, fully integrated sample and hold circuit (OS/H) is described. Measured results are presented that demonstrate operation of this circuit at 250 Ms/s and with effective resolution approaching 8 bits. The integrated circuit, which measures 2.1 mm×1.4 mm, is realized in -1.0-V threshold, 20-GHz ft GaAs MESFET technology, consumes approximately 200 mW of power, and requires one optical address. The OS/H will find applications in high precision, hybrid, and integrated signal processing systems where high speed, high levels of parallelism, and low timing jitter are important. Measured results of a series photoconducting (Auston switch) OS/H realized in the same technology are presented for comparison purposes     

Wide-band fiber optic signal processor

Operation of a 16-tap fiber-optic delay line configured as a bandpass filter with a fundamental frequency of 2.0 GHz over the frequency range from 0 to 12.5 GHz is discussed. Equal tap weights and spacings were used to facilitate comparison of experimental and predicted results. More than 10¹¹ analog multiplications per second are performed in this relatively simple signal processing system. Other processors for performing functions such as matched filtering and correlation can be implemented by appropriate choice of the mirror reflectances and fiber lengths     

Effects of fibinolysis on neurite growth from dorsal root ganglia cultured in two- and three-dimensional fibrin gels

The mechanism of neurite penetration of three-dimensional fibrin matrices was investigated by culturing embryonic chick dorsal root ganglia (DRGs) within fibrin gels, upon fibrin gels, and upon laminin. The length of neurites within three-dimensional matrices of fibrin was decreased in a concentration-dependent manner by agents that inhibited plasmin, e.g. aprotinin, or that inhibited plasminogen activation, e.g., epsilon-aminocaproic acid (EACA), or plasminogen antiserum. In contrast, such agents increased the length of neurites growing out from DRGs cultured upon two-dimensional substrates of fibrin and had no effect on the length of neurites growing out from DRGs cultured upon laminin. Visualization of neurites within three-dimensional fibrin matrices demonstrated that the distance between fibrin strands was much smaller than the diameter of neurites. All these data were consistent with the hypothesis that fibrinolysis localized to the region of the neurite tip is an important mechanism for neurite penetration of a physical barrier of fibrin strands arranged in a three-dimensional matrix.     

Dissecting cAMP binding domain A in the RIalpha subunit of cAMP-dependent protein kinase. Distinct subsites for recognition of cAMP and the catalytic subunit

The two gene-duplicated cAMP binding domains in the regulatory subunits of cAMP dependent protein kinase are each comprised of an A helix, an eight-stranded beta-barrel, and a B and C helix (1). The A domain is required for high affinity binding to C, while the B domain regulates access to the A domain. Using a combination of a yeast two-hybrid screen coupled with deletion analysis, cAMP binding domain A of RI was dissected into two structurally and functionally distinct subsites, one that binds cAMP and another that binds the C subunit. The minimum stable subdomain required for binding to C in the 1-3 micromolar range is composed of residues 94-169, while residues 236-244, mapped to the C helix of cAMP binding domain A, were defined as a second surface necessary for high affinity (5-10 nanomolar) binding to C. This portion of the C helix, due to its position directly between the two subsites, serves as a molecular switch for either a cAMP-bound conformation or a C-bound conformation and can thus modulate interactions of cAMP binding domain A with cAMP, with C, and with cAMP binding domain B.     

Prediction of fatigue behaviour in stress-concentrators of arbitrary geometry

A new method is outlined which aims to predict high-cycle fatigue behavior of components which fail from stress-concentrators. This involves examination of the stress field in the vicinity of the stress-concentrator, and comparison with stress fields for cracks at known stress intensities. Methods which are currently used for simple notch geometries can thus be generalised, making the approach applicable to stress concentrators of any geometry. The method of prediction is shown to be stable, providing a solution of good accuracy when compared to analytical methods for standard specimen geometries. Favourable comparisons with experimental data have been achieved both for standard notches and for a corner geometry which represents a typical component case.