Showing papers on "Filter (video) published in 1978"

Air purification electrostatic charcoal filter and method

Abstract: An air purification filter is provided which has a housing; an inlet in the housing for air to be purified; a microporous filter medium, activated charcoal, which is placed in the housing so that the air to be purified passes through this microporous filter medium. The microporous filter medium serves as an electrostatic filter, with the air, including the particulate matter in the air, being charged to one polarity just prior to reaching the microporous filter medium, and with the microporous filter medium itself being directly charged, with an electrode at the downstream surface of the microporous filter medium. In a preferred embodiment an odor neutralizing medium bearing a charge opposite to that of the microporous filter medium is placed upstream of the microporous filter medium.

Stackable filter head unit

Abstract: A filter assembly utilizing a plurality of stackable filter head units which permit parallel flow through filter elements mounted within filter bowls, there being one filter element and filter bowl mounted on each of the stackable filter head units. An improved filter head construction is employed which permits a plurality of substantially identical filter head units to be mounted adjacent each other to provide the desired flow capacity, each of the filter head units being so designed that it can be readily manufactured.

Optimal location of measurements for distributed parameter estimation

Abstract: The problem of optimal measurement locations for state estimation in linear distributed parameter systems is considered. It has previously been shown that the optimal sensor location problem for distributed systems can be posed as an optimal control problem for a system described by the infinite-dimensional matrix Riccati equation for the filter covariance. A more efficient approach based on an upper bound of the filter covariance is developed in the present study. The relationship between the present approach and that of minimizing a measure of the filter covariance is studied. A detailed example is considered, and the results of the two approaches are compared.

Narrow optical bandpass filter via nearly degenerate four-wave mixing.

Abstract: It is shown that a nearly degenerate four-wave mixing process is capable of yielding a real-time optical bandpass filter. The filter has a large field of view and is capable of providing an amplified bandpass. Moreover, the conjugate nature of the output field can be utilized to increase the signal-to-noise ratio of the device. For a 1-cm interaction length in a nondispersive medium, the optical bandpass at 5000 A can be varied from ~9 GHz down to the linewidth of the exciting laser.

Inertial filter of the porous metal type

Abstract: A porous filter is formed of sintered metal particles and is characterized by having sintered metal particles of relatively large size throughout and a thin subsurface area adjacent the upstream surface containing sintered metal particles of relatively small size, thus providing a thin area of relatively small pore size adjacent the upstream surface while the remaining major portion of the filter has a relatively large pore size. The filter is particularly useful as an inertial filter and as a support for reverse osmosis membranes.

A decentralized computational algorithm for the global Kalman filter

Abstract: In this paper a new decentralized computational structure is developed for Optimal state estimation in large scale linear interconnected dynamical systems. The new filter uses a hierarchical structure to perform successive orthogoilalizations on the measurement subspaces of each sub-system in order to provide the optimal estimate. This ensures substantial savings in computation time. In addition, since only low-order subsystem equations are manipulated at each stage, numerical inaccuracies are reduced, and the filter remains stable for even high-order systems. This is illustrated on a multimachine example of a system comprising eleven interconnected machines.

Adaptive line enhancer

Abstract: An input signal X(j) is fed directly to the positive port of a summing function and is simultaneously fed through a parallel channel in which it is delayed, and passed through an adaptive linear transversal filter, the output being then subtracted from the instantaneous input signal X(j). The difference, X(j)-Y(j), between these two signals is the error signal e(j). e(j) is multiplied by a gain μ and fed back to the adaptive filter to readjust the weights of the filter. The weights of the filter are readjusted until e(j) is minimized according to the recursive algorithm: ##EQU1## where the arrow above a term indicates that the term is a signal vector. Thus, when the means square error is minimized, W.sub.(j+1) =W.sub.(j), and the filter is stabilized.

Active R filters: review of theory and practice

Abstract: Active filters that derive their frequency response from internal amplifier dynamics, but use no external capacitors in their implementation, are referred to as “active R” filters. Because of their potential advantages in terms of miniaturisation (i.e. fabrication), ease of design and high-frequency performance, these circuits are receiving increasing attention in the technical literature. The paper reviews the published synthesis procedures for 1st-, 2nd- and higher-order active R filters; it is shown that the 1st- and 2nd-order circuits developed to date are special cases of a general active R topology. The paper discusses nonideal aspects and limitations of active R filter performance, which arc usually neglected in the literature; in particular, the potentially severe effect of temperature-induced drift in the amplifier's dynamic response is considered, and methods of drift compensation are discussed. Experimental results are presented to verify filter performance and the theoretical derivations

The Magneto-Optical Filter. II. Velocity Field Measurements

Abstract: In this paper we describe a filter which utilizes magneto-optical effects for velocity fields measurements. The working principle of the instrument is described and its transmission profiles are given. Velocitygrams are shown of the five minutes oscillations (FMO) and the results compared with the expected (theoretical) signal from the instrument. We found a Vrms of 400 m s−1 for the FMO.

Specific structures for large-scale state estimation algorithms having information exchange

Abstract: This paper considers the design and evaluation of large-scale state estimation algorithms having specific structures which allow the subsystems to exchange information over noisy channels. The specific structures which are presented are first motivated by considering the relative performance between the surely locally unbiased filter and a global dynamics filter. The role of the surely locally unbiased filter in evaluating the tradeoffs between the cost of information transfer and filter performance is examined and a theorem is presented which forms the basis for an algorithm for calculating channel noise crossover levels. The theoretical results are illustrated via an application to a power system model.

Electrostatic air filter having honeycomb filter elements

Abstract: An electrostatic air filter for the removal of particulate matter such as dust, smoke and the like from air. The filter has an ionizing section in which the particles are electrically charged and a filter section defined by one or more dielectric honeycomb filter elements arranged so that the air flows through the honeycomb cells. The filter elements are placed in an electric field so that the previously charged particles are deflected sideways as they flow through the honeycomb cells and impinge on and adhere to the cell walls. The honeycomb cells are periodically cleaned or replaced with new ones.

Air filter arrangement to permit cleaning without removing element

Abstract: An air filter for use on internal combustion engines which operate primarily in heavy dust conditions, and which includes a mounting member as part of the air filter housing that permits the spinning of the air filter cartridge for centrifugal cleaning in place on the internal combustion engine, without removal of the filter cartridge from the air filter housing.

Conditioning assembly for continuous stack monitoring

Abstract: A probe for obtaining particulate-free samples of gas from a smoke stack for a power plant or other industrial installation. The probe comprises a coarse filter, with means for periodic cleaning by blowback, protecting the inlet to an inertial filter. A high velocity flow of coarsely filtered stack gas is established through the inertial filter. Sample gas is withdrawn from the inertial filter at a low rate in a direction orthogonal to the gas stream through the inertial filter so as not to disturb particles in the inertial filter stream. The invention eliminates the necessity for frequent maintenance of stack mounted filters or other stack mounted components.

Electric coffee maker

Abstract: An electric coffee maker having a coffee pot in the form of a Dewar flask supported in a shock-proof outer housing surrounding the flask. A fresh water container and a coffee filter are disposed above the coffee pot. An electric flow-through heater is disposed in the housing below the top of the Dewar flask. Fresh water conduit means are conducted from the fresh water container through the interior of the housing to the flow-through heater. The hot-water conduit means from the heater to the top of the filter are routed through a handle formed from the housing.

An Extended Kalman-Bucy Filter for Atmospheric Temperature Profile Retrieval with a Passive Microwave Sounder.

Abstract: An extended Kalman-Bucy filter has been implemented for atmospheric temperature profile retrievals from observations made using the Scanned Microwave Spectrometer (SCAMS) instrument carried on the Nimbus 6 satellite. This filter has the advantage that it requires neither stationary statistics in the underlying processes nor linear production of the observed variables from the variables to be estimated. This extended Kalman-Bucy filter has yielded significant performance improvement relative to multiple regression retrieval methods. A multi-spot extended Kalman-Bucy filter has also been developed in which the temperature profiles at a number of scan angles in a scanning instrument are retrieved simultaneously. These multi-spot retrievals are shown to outperform the single-spot Kalman retrievals.

Real-time edge processing unit

Abstract: A digital machine for detecting and processing pictorial edges in video data. The invention mechanizes, in parallel, three different processing techniques, the outputs of which are combined in a selectable manner to generate processed and enhanced video data. The first parallel processor convolves four inter-related 3×3-element masks with the 2-dimensional video input data to locate the pictorial edges, to determine the edge directions, to execute edge connectivity logic, and to calculate certain edge statistics. The second parallel processor implements a 3×3 element, low or high pass image filter, and an adaptive threshold filter. Both the first and the second parallel processors use Fast-Form algorithms which allow data processing in real time with a minimum of components. The third parallel processor operates on the video data in serial form to generate the video output from the edge processing unit. The third processor is interconnected with the first two processors so as to process and enhance selected features of the serial video data in accord with the outputs from the first two processors.

Exchangeable filter element

Abstract: An exchangeable filter element is disclosed. The filter element is especially adapted for nuclear installations for the purification of gas streams which contain toxic or radioactive matter. A method is also disclosed for the exchange and disposal of contaminated filter elements, which filter elements are reducible in volume for packing into waste containers.

Principles and Simulation of JTIDS Relative Navigation

Abstract: The time-synchronous operation and high accuracy time-of arrival (TOA) measurement capability of Joint Tactical Information Distribution System (JTIDS) terminals makes possible a high performance relative nagivaton (RELNAV) function through addition of only software in the terminal's computer program. The principles of operation, the basic observation equations, and the system architecture for both absolute (geographic) and relative navigation are described. Sequential passive ranging by means of the TOA measurements, in conjunction with appropriate source selection logic and a recursive (e. g., Kalman) filter mechanization are employed to determine the user's position, velocity, and time bias. The filter algorithms and error sources, the software functional flow, and some simulation results are presented.

Filter housing and filter assemblies utilizing the same

Abstract: The specification discloses a two-piece twist apart filter housing adapted to be interposed in a conduit supplying or receiving air or other medium from a device, wherein the two parts of the housing can be twisted apart to permit replacement of the various types of filter media without detaching either end of the filter housing from said conduit. There are also disclosed particular filter assemblies utilizing said filter housing wherein there is provided a particulate filter, a coalescing filter, and an odor filter assembly which can easily be removed and replaced when needed without removing the filter housing from the supply line.

Filter element support member

Abstract: A filter element support assembly for use with hollow, cylindrical, pleated media filter elements is disclosed. The filter elements are placed on the support in end-to-end abutting relationship. The support includes a plurality of baffle plates in parallel spaced relationship, which isolate the interior chamber of each filter element from those of the support assembly into the interior chambers of the filter elements. The tubes are not only the primary structural members of the assembly, but also serve the dual function of providing a means of fluid communication between each isolated filter element chamber and a clean air plenum and source of compressed air, and of guiding and positioning the filter elements in their proper locations.

Fully-integrated high-order NMOS sampled-data ladder filters

Abstract: This paper will disclose an approach for implementing NMOS sampled-data recursive filters by using switched-capacitor integrators in an active ladder configuration. Experimental results for a fifth order Chebyshev 3400Hz low-pass filter with 0.1dB passband ripple will be presented.

On an adaptive algorithm for IIR filters

Abstract: The purpose of this communication is to discuss an IIR adaptive filter algorithm developed by Stearns [1], in terms of an example that appeared in a recent article [2]. The example concerns the approximation of a fixed second-order filter by a first-order adaptive filter, when subjected to a white noise input.

The derivation of switched-capacitor filters from active-RC prototypes

Abstract: A general procedure is given for the design of an active switched-capacitor filter from an actlve-RC model. The process is based on trapezoidal integration. The resulting sampled-data circuit response is related to that of the model through the bilinear z-transformation.

Training aid for use with night vision apparatus

Abstract: A filter arrangement is described which is incorporated with a night vision device. The filter arrangement consists of a variable density polaroid filter array and a blue-green filter all contained in a common housing and directed along a given optical path. The filter arrangement serves to control the amount of light directed to an input port of a night vision device such as a pair of goggles. In this manner, a user can be trained to employ the night vision device under direct supervision in daylight conditions and by variation of the polarizing plates is enabled to simulate nighttime conditions.

Speech synthesis integrated circuit device

Abstract: Disclosed is an integrated circuit device or chip which digitally synthesizes human speech using a linear predictive filter. This device may be implemented using conventional processing techniques. For instance, when implemented in conventional P-channel MOS technology, the disclosed device or chip has an active area of approximately 45,000 square mils.

Autogenously bonded filter assemblies

Abstract: An autogenous or sinter bond between metallic filter media and other metal components of a filter assembly is produced by joining the parts through a diffusion bonding membrane. The membrane comprises a web of small diameter metal fibrils which will sinter bond to both the filter media and the other filter parts to form a physically strong and leak-free seal.

Estimation and filter stability of stochastic delay systems

Abstract: Linear and nonlinear filtering for stochastic delay systems are studied. A representation theorem for conditional moment functionals is obtained, which, in turn, is used to derive stochastic differential equations describing the optimal linear or nonlinear filter. A complete characterization of the optimal filter is given for linear systems with Gaussian noise. Stability of the optimal filter is studied in the case where there are no delays in the observations. Using the duality between linear filtering and control, asymptotic stability of the optimal filter is proved. Finally, the cascade of the optimal filter and the deterministic optimal quadratic control system is shown to be asymptotically stable as well.

Filter retaining latch

Abstract: A latch assembly for removably clamping a unit filter cell in position against a flow-through frame structure includes a shaft spaced from the flow-through frame structure and mounted for rotational movement about its longitudinal axis and for movement transverse to its longitudinal axis toward and away from the flow-through filter frame. The shaft also includes filter cell contacting elements. The shaft is also biased toward the flow-through frame structure. A unit filter cell is disposed between the shaft and flow-through frame structure and is held in place against the frame structure upon rotation of the biased shaft which brings the filter cell contacting elements into contact with the unit filter cell.

Multiple-amplifier RC-active filter design with emphasis on GIC realizations (Invited Paper)

Abstract: The use of more than one amplifier to realize an RC-active filter is now economically viable because of the relatively low cost of high-performance operational amplifiers. In this review article, multipleamplifier RC-active synthesis and design techniques are considered. Multiple-amplifier circuits are described that use generalized immittance converters or integrators to realize low-sensitivity high-quality biquadratic circuits and active ladder circuits.