Showing papers on "Filter (video) published in 1986"

A variable step (VS) adaptive filter algorithm

Abstract: In recent work, a new version of an LMS algorithm has been developed which implements a variable feedback constant μ for each weight of an adaptive transversal filter. This technique has been called the VS (variable step) algorithm and is an extension of earlier ideas in stochastic approximation for varying the step size in the method of steepest descents. The method may be implemented in hardware with only modest increases in complexity ( \approx 15 percent) over the LMS Widrow-Hoff algorithm. It is shown that an upper bound for the convergence time is the classical mean-square-error time constant, and examples are given to demonstrate that for broad signal classes (both narrow-band and broad-band) the convergence time is reduced by a factor of up to 50 in noise canceller applications for the proper selection of variable step parameters. Finally, the VS algorithm is applied to an IIR filter and simulations are presented for applications of the VS FIR and IIR adaptive filters.

Creating Raster Omnimax Images from Multiple Perspective Views Using the Elliptical Weighted Average Filter

Abstract: Creation of Omnimax animation by computer opens up fantastic new visual possibilities. Unfortunately, the fish-eye distortion of Omnimax film images complicates synthesis by computer, since most image-synthesis programs can create only perspective views. As an alternative to modifying existing image-synthesis programs to produce Omnimax projections directly, we present a method for creating them from multiple perspective views. Four perspective views of the environment are created, each a projection onto a face of a cube centered at the camera, and then a mapping program creates an Omnimax projection from them. To minimize aliasing during resampling, the mapping program uses the elliptical weighted average filter, a space-variant filter we developed for this application that computes a weighted average over an arbitrarily oriented elliptical area. This filter can also be used for texture mapping 3D surfaces.

Blood separation device comprising a filter and a capillary flow pathway exiting the filter

Abstract: A method for separating plasma from red blood cells and a device utilizing the method in which a low-pressure filter is interposed in a pathway between an inlet port and a reaction area. The sole driving force for the movement of plasma from the filter to the reaction area is capillary force provided by a tubular capillary. The filter is selected from glass microfiber filters of specified characteristics, which can operate in the absence of agglutinins, and filters capable of separating agglutinated red cells from a plasma, which require the use of an agglutinin.

Multiwell test plate

Abstract: A micro-titre test plate includes a thermoplastic incubation tray having an array of a plurality of wells extending therethrough, a filter, and a thermoplastic harvester tray for supporting the filter sheet. The harvester tray has a plurality of apertures therethrough arranged to be registerable with the bottoms of the wells in the incubation tray. To prevent cross-talk between the wells along the filter, the facing surfaces of the harvester tray and incubation tray are provided with mating ridges and grooves circumscribing the juncture of each well and aperture. In one embodiment, the ridges and grooves are thermally bonded to one another to provide a fluid-impervious barrier trapping respective filter disks in the juncture of each well and aperture. In another embodiment, the harvester tray is formed of a pair of apertured, thermoplastic sheets nested with respective thermally bonded grooves and ridges to trap the filter, the harvester tray being not necessarily bonded to the incubation tray.

Corrections to an elliptic continuous-time CMOS filter with on-chip automatic tuning

Abstract: A voice-band continuous-time filter is described which was designed based on the technique of fully balanced networks and was fabrication in a 3.5-/spl mu/ CMOS technology. The filter implements a fifth-order elliptic low-pass transfer function with 0.05-dB passband ripple and 3.4 kHz cutoff frequency. A phase-locked loop control system fabricated on the same chip automatically references the frequency response of the filter to an external fixed clock frequency. The cutoff frequency was found to vary by less than 0.1% for an operating temperature range of 0-85/spl deg/C. The absolute value accuracy of the cutoff frequency was 0.5% (standard deviation). With /spl plusmn/5-V power supplies the measured dynamic range of the filter was approximately 100 dB.

Varactor Tuned Bandpass Filters Using Microstrip-Line Ring Resonators

Abstract: This paper describes the fundamental characteristics and experimental results of newly developed tunable bandpass filters using rnicrostrip-line ring resonators. The experimental filter has a steeper attenuation slope and less circuit instability than conventional filters, and it seems to be a suitable filter for MICs or MMICs.

Room air treatment system

Abstract: A room air treatment system in which air is drawn through a large particle prefilter, a first carbon filter, a second dual honeycomb matrix carbon filter in which the honeycomb cells in adjacent matrices are offset relative to one another, a blower mounted on vibration isolation mounts and is expelled by the blower into a plenum from when it exits upwardly through a fine particle HEPA filter and finally out through a final filter which is a combination fine particle filter and carbon filter. A filter change warning system is provided which includes a 3500 hour filter change indicator, an every 7000 hour filter change indictor, a back-up warning indicator, a mute button for muting the warning indicator and a recycle system for restarting the hour count.

Adaptive filters with individual adaptation of parameters

Abstract: Conventional gradient-type adaptive filters use the fixed convergence factor \mu which is normally chosen to be the same for all the filter parameters. In this paper, we propose to use individual convergence factors which are optimally tailored to adapt individual filter parameters. Furthermore, we propose to adjust the individual convergence factors in real time so that their values are kept optimum for a new set of input variables. We call this approach "individual" adaptation as opposed to the conventional fixed "group" adaptation using the same fixed \mu for all the filter parameters. Computer simulation results show that the individual adaptation approach yields much better filters than the conventional fixed group adaptation approach. Optimization of individual time-varying convergence factors leads to a constraint which may be satisfied by several different algorithms. We propose and investigate here two algorithms satisfying the above constraint: individual adaptation (IA) and homogeneous adaptation (HA). The HA algorithm turns out to have the general form as some well known gradient algorithms that normalize the step size which were previously obtained either intuitively or using involved derivations. Both IA and HA are shown to provide much better performance than the conventional "group" adaptation. However, for several simulations, IA provides better performance than HA, at the expense of increased computation.

Programmable digital hearing aid system

Abstract: A hearing aid system comprises a hearing aid that is programmable so as to have optimum electro-acoustic characteristics for the patient and acoustic environment in which it is used. Selected optimum parameter values are programmed into an electronically erasable, programmable read only memory (EEPROM) which supplies coefficients to a programmable filter and amplitude limiter in the hearing aid so as to cause the hearing aid to adjust automatically to the optimum set of parameter values for the speech level, room reverberation, and type of background noise then obtaining. The programmable filter may be a digital equivalent of a tapped delay line in which each delayed sample is multiplied by a weighting coefficient and the sum of the weighted samples generates a desired electro-acoustic characteristic. Alternatively, the programmable filter may be a tapped analog delay line in which the sum of the weighted outputs of the taps generates the desired characteristics. Acoustical feedback is reduced by an electrical feedback path in the hearing aid which is matched in both amplitude and phase to the acoustic feedback path, the two feedback signals being subtracted so as to cancel each other.

Strip line filter

Abstract: PURPOSE: To miniaturize a filter and to reduce the cost by putting a dielectric substrate, on which plural electrodes for capacity are formed, from near open ends of respective resonance electrodes to an earth electrode and conductively joining end parts of respective electrodes for capacity and parts near open ends of respective resonance electrodes. CONSTITUTION: One principal surface of a second dielectric substrate 16 is put from parts near open ends of respective resonance electrodes 8 of a dielectric substrate 2 onto a side 62 of an earth electrode 6 facing them, and plural electrodes 18 for capacity which correspond to respective resonance electrodes 8 and are extended from parts near open ends of respective resonance electrodes 8 onto the side 62 of the earth electrodes 6 facing thems are formed on the other principal surface. End parts of electrodes 18 for capacity and parts near open ends of respective resonance electrodes 8 are conductively joined with a conductive cement 14 like a solder or a conductive paste. Thus, the length of the resonance electrode 8 is shortened to miniaturize a filter, and assembling is simplified because one second dielectric substrate 16 is attached to give an overall electrostatic capacity. COPYRIGHT: (C)1988,JPO&Japio

Single-block dual-passband ceramic filter useable with a transceiver

Abstract: A single-block ceramic filter (100) providing both pass and stop bands couples an RF signal from transmitter (180) to an antenna (190) and an RF signal from the antenna (190) to a receiver (170). The ceramic filter (100) includes seven holes (102, 104, 106, 108, 110, 112 and 114) each having an elongated cross section and being surrounded by capacitive strips (e.g. 130, 131, 140 and 141 for hole 106), and electrodes (120, 122 and 124) coupled to receiver (170), transmitter (180) and antenna (190), respectively. A bracket (150) may be soldered to the ceramic filter (100) for holding cables coupled to the receiver, transmitter and antenna and for mounting the ceramic filter in a radio transceiver.

Synthesis and analysis of state-space active filters using intermediate transfer functions

Abstract: This paper is concerned with the realization of a given arbitrary filter transfer function as a network of resistively interconnected integrators. These state-space realizations are synthesized using a new technique called intermediate function (IF) synthesis. The technique is based on the selection of a set of functions to serve as either the transfer functions from the filter input to the integrator outputs or the transfer functions from the integrator inputs to the filter output. Relationships between the filter sensitivity and dynamic range and the intermediate functions are derived. A number of results are also given to aid in the selection of a set of IF's that yields structures with optimum performance.

Active filter for reactive power and harmonics compensation

Abstract: This paper describes a three-phase active filter aimed at the compensation of reactive power and current harmonics of a symmetrical load. The filter employs an inductor for energy storage and a two-quadrant PWM bridge converter.

Long-Term Effectiveness and Maintenance of Vegetative Filter Strips

Abstract: ...............................................................................................................................................vi

Disposable filter cartridge, whether or not combined with a water reservoir

Abstract: A disposable filter cartridge comprising a housing substantially including a bottom and an upright side wall, the underside or bottom having one or more holes, said filter cartridges being provided at its top and at least a part of its bottom with filter material or a filter film. At least the filter material for the top is connected to the side wall or a flange-shaped extension thereof by means of a sealed joint. The filter material destined for the underside or bottom of the housing is cup-shaped and is received in the housing of the filter cartridge so as to be immovable.

High-frequency voltage-controlled continuous-time lowpass filter using linearised CMOS integrators

Abstract: The design and implementation of a continuous-time lowpass filter with voltage-controlled cutoff frequency and passband ripple is presented The circuit uses a linearised CMOS transconductor as a basic integrating building block A voltage-controlled phase-adjusting scheme is employed in the integrator to compensate for excess phase in the transconductance at high frequencies The fabricated filter is capable of realising cutoff frequencies as high as 2 MHz and handles single-ended input signals up to 4 V p-p with less than 1% distortion

A comparison of five heat and moisture exchangers

Abstract: Summary Five heat and moisture exchangers were investigated to compare their efficiency of humidification, their ability to filter bacterial spores and their various physical properties The results are presented and the various mechanisms of heat and moisture exchange are reviewed The Pall Ultipor BB50 because of its hydrophobic properties, has a slightly different action from heat and moisture exchangers already in use The place of the Pall Ultipor BB50 in clinical practice is discussed

Geometric Filter For Reducing Speckle

Abstract: A nonlinear speckle filter based on geometric concepts is defined, and an example of its effectiveness on synthetic aperture radar imagery is shown. Comparison with look-averaging is made using artificial imagery with synthetic speckle.

Device for reading a color image from an original document with reciprocating filter

Abstract: A color document image reading device provides for inputting of a color image on an original document to various kinds of image processing apparatus. The color document image is decomposed into predetermined pixels, then photoelectrically converted into an electric signal, and then outputted with the pixels arranged time-serially. A filter has a plurality of color separation filter elements which are arranged in a flat configuration while being physically isolated from each other by a light-intercepting area having a predetermined width. The filter is driven by filter drive means in a reciprocal motion in a direction perpendicular to an optical axis, whereby any of the filter elements is brought into alignment with the optical axis. The filter is supported in such a manner as to be movable in a direction of movement of the filter drive means while being prevented from moving in the other directions.

Method and apparatus for coupling transceiver to power line carrier system

Abstract: A method and apparatus for efficiently coupling a transceiver to an AC power line transmission system. The preferred embodiment of the coupling system comprises a line coupling network and first and second filter ports. The first filter port is connected to a resonant circuit having bandpass filtering characteristics adapted to the specific needs of the transmitter portion of the transceiver. The second filter port is isolated from the low impedance of the AC power line and is connected to a high quality factor filter having bandpass filtering characteristics adapted to the specific needs of the receiver portion of the transceiver.

Adaptive filter for dual energy radiographic imaging

Abstract: A radiographic scanner (A) generates a high energy image representation which is stored in a high energy image matrix (V) and a low energy image representation which is stored in a low energy image memory (U). A pair of filter functions selecting circuits (C) select a first or soft tissue specific filter function and second or bone specific filter function, respectively. The soft tissue filter function selecting circuit selects and adjusts the soft tissue filter function in accordance with the pixel value of the low energy image representation for each corresponding pair of pixel values. Convolvers (44, 46) convolve pixel values from the high and low energy image representations with the selected and adjusted filter functions. A soft tissue transform function (48) transforms the filtered high and low energy image representations into a soft tissue or other material specific image representation (42). The other filter selecting and adjusting circuit selects and adjusts the bone specific filter functions which are convolved with the high and low energy image representations by convolvers (54, 56). A bone specific transform function (58) transforms the filtered high and low energy image representations into a bone basis image.

Toward the Application of the Kalman Filter to Regional Open Ocean Modeling

Abstract: A partial differential equation model is defined for ocean meteorological prediction and synoptic analysis. The Kalman filter used for data assimilation is described and applied to the one-dimensional linear barotropic quasi-geostrophic model with periodic and open boundary conditions. The model accounts for eddy scale dynamics in the ocean. The assumptions made in the forecast model are discussed, along with comparisons of the error variances expected with the filter and from an objective analysis method. The effectiveness of the Kalman filter is demonstrated and subsequent efforts to extend the filter to two dimensions are indicated.

Digital filter switch for data receiver

Abstract: A digital filter switch for use with a data receiver incorporates first and second squaring units connected to the outputs of first and second band-pass filters tuned to the separation and character frequencies in a signal transmission. The outputs of the squaring units are interconnected via an adder to the input of a low-pass filter, which produces the output data signal.

Aerosol sampling efficiency of 37 mm filter cassettes

Abstract: This research compared the sampling efficiencies of open- and closed-face 37 mm filter cassettes and an experimental cassette with a tapered inlet. The experiment involved challenging the cassettes with various aerosol sizes up to 24 µm Mass Median Aerodynamic Diameter (MMAD) in a wind tunnel operated at 100 cm/sec. Sampling efficiencies were determined by comparing cassette mass concentration measurements to paired isokinetic samples. It was found that sampling efficiencies dropped with increasing particle size and that the cassette with the tapered entry offered no improvement to sampling efficiency. Sampling efficiency appeared to be improved by placing cassettes on a manikin to simulate personal sampling.

Air actuated automatic lint screen cleaning system for dryer

Abstract: An air actuated lint removing system for cleaning lint filters in clothes dryers includes means for moving the lint filter and an air flow directing means with respect to one another to remove accumulated lint, and lint transporting means to move the lint to a lint collection reservoir.

Bandwidth compression for television signals

Abstract: A video signal received from a source (10) is bandwidth-compressed by filters (12, 14, 16), filter (14) being a temporal filter and filter (16) being a spatial filter. Selection of the filter to be used is dependent upon picture content. The transmitter reconstitutes in interpolators (44, 46) the signal which would be regenerated at the receiver, determines which filter gives the best results, and transmits an indication of which filter has been used in a digital signal associated with the analogue video signal. Preferably a determination of motion vectors associated with the signal is made and the digital signal indicates which of the determined motion vectors is applicable to different areas of te picture. By transmitting the control signal digitally with the analogue video signal the receiver circuitry is greatly simplified while its reliability is improved.

Temperature responsive bypass filter assembly

Abstract: A filter assembly for removing particles from a fluid which comprises first and second filters, each having a porous filter medium. The mean pore diameter of the porous filter medium of the second filter is greater than the mean pore diameter of the porous filter medium of the first filter. The filter assembly further comprises structure for directing the fluid serially through the first filter and then through the second filter, a mechanism for sensing the temperature of the fluid, and a valve arranged in parallel with the first filter and serially with the second filter. The valve is coupled to the temperature-sensing mechanism so that at least a portion of the fluid is directed around the first filter in response to a predetermined fluid temperature. For example, in the illustrated embodiment, the fluid is directed around the first filter when the fluid temperature is below a predetermined value.

Efficient implementations of quadratic digital filters

Abstract: Efficient implementation structures of quadratic filters are introduced in this paper using systolic arrays, distributed arithmetic, and linear convolutions with multipliers. The implementations are based on matrix decompositions and consist of a set of parallel 1-D FIR filters in cascade with a set of sequential square-in add-out type of operations. The structures are compared using various realistic figures of merit such as data throughput delay, cost that is proportional to chip area, and variance of roundoff errors in the filter output assuming fixed-point arithmetic. For comparison purposes, the direct and Biglieri quadratic structures are included in this study. Evaluating the comparative results, the conclusion drawn is that the matrix decomposition realization of a quadratic filter implemented with systolic arrays seems to be offering the best compromise among the various conflicting figures of merit.