Showing papers on "Filter (video) published in 1972"

Frequency Filter for Time Integrations

Abstract: A simple filter for controlling high-frequency computational and physical modes arising in time integrations is proposed. A linear analysis of the filter with leapfrog, implicit, and semi-implicit, differences is made. The filter very quickly removes the computational mode and is also very useful in damping high-frequency physical waves. The stability of the leapfrog scheme is adversely affected when a large filter parameter is used, but the analysis shows that the use of centered differences with frequency filter is still more advantageous than the use of the Euler-backward method. An example of the use of the filter in an actual forecast with the meteorological equations is shown.

On the design of digital filters with coefficients of limited word length

Abstract: The cost of a digital filter, if implemented as a special-purpose computer, depends heavily on the word length of the coefficients. Therefore, it should be reduced as much as possible. On the other hand, a small word length causes large coefficient deviations that impair the wanted performance of the digital filter. The necessary word length may be reduced by choosing a suitable structure for the filter. Two methods for doing this will be presented, taking selective filters as a model. A further reduction of the word length may be won by optimizing the rounded filter coefficients in the discrete parameter space. A description of a modified univariate search will be given.

A Video-Dimension Analyzer

Abstract: A dual-window video densitometer was developed for the measurement of dimensions of televised scenes. Filter and hold circuitry used to convert the output into analog signals proportional to the dimension being measured obviate the use of specialized computers. The system was utilized to study the change of dimension of the in vivo human heart.

Apparatus for improving video signal-to-noise ratio

Abstract: An input video signal is coupled to one input of a summing amplifier, to the input of a low-pass filter, and to one input of a movement detector. The output signal from the apparatus is delayed by one frame interval, and this delayed output signal is coupled to a second input of the summing amplifier and to a second input of the movement detector. The movement detector is of a type which generates a control signal to indicate movement in response to a plurality of frame-to-frame differences for adjacent picture elements. This control signal is utilized to selectively gate either the output from the summing amplifier or the output of the low-pass filter through to an output terminal.

Liquid filter and method for fabricating same

Abstract: A liquid filter including at least two filter members having continuously contacting opposing surfaces, the members each being fabricated of a non-porous material, wherein at least a segment of a liquid flow path through the filter is defined at the interface of the contacting surfaces. A method of manufacturing the above filter comprising the steps of forming a groove in at least one of the opposing surfaces of the filter members and then mounting the filter members together in continuous superimposed contacting relation with the groove lying at the interface and defining at least a segment of a liquid flow path through the filter at said interface. In a preferred embodiment, the forming step includes chemical etching and the mounting step includes diffusion bonding.

Hand propelled swimming pool cleaner

Abstract: A hand propelled or operated swimming pool cleaner is disclosed comprising a wheeled frame having a motor driven pump mounted thereon. The pump is adapted to pick up dirt particles or the like from the pool floor and pump the same through a filter to remove the particles from the water. An elongated handle is secured to the cleaner to permit a person at poolside to manually maneuver the cleaner to clean the bottom of the pool.

Range resolving doppler radar system

Abstract: A system for measuring unambiguous target range for targets at high velocities in which target range and doppler frequency data from three sequential transmission dwells of radar returns are stored, each dwell having a different pulse repetition frequency (PRF). The dwell storage unit which includes three sets of dynamic registers is loaded and unloaded serially with respect to range and supplied to a 17 path doppler frequency correlator. After the three dwell storage registers have been loaded with a basic PRF plus jitter, the range interval unfolding is performed by a recirculation process in each of the registers. During recirculation the data is applied to a correlation unit, the purpose of which is to insure that the velocity of the target satisfies a 17 path algorithm across three adjacent dwells in at least one of five range azimuth profiles or paths. Because the same target velocity may cause outputs in adjacent doppler filters due to PRF jitter, the correlation utilizes a criteria that for all three possible PRF sequences the filter numbers across the three range bins and paths must be within one of each other. As the filter correlation function is capable of multiple path selection the filter path outputs are priority selected to produce a valid target. The final output from the system is a verification that the data in the three range bins of interest satisfies the seventeen path correlation algorithm formed of three dwells and three adjacent range bins with a possible PRF jitter of one filter in each range bin.

Installation for the mechanical-biological purification of waste water

Abstract: An installation for the mechanical-biological purification of waste water or sewage incorporating at least one biological stage and one post-clarification stage, the post-clarification stage incorporating a filter. The filter is a drum filter having a filter surface wherein at the inflow or deposit side thereof there engages a suction nozzle which extends transversely with respect to the direction of relative movement between the filter surface and the suction nozzle.

Method and machine for the production of composite filter mouthpieces

Abstract: Filter mouthpieces with one or more thin filter disks of first filter material and one or more filter plugs of second filter material are produced by inserting alternating filter plugs and filter disks into prefabricated tubes which move sideways, by inserting filter disks between filter plugs which form a single file and travel with a web of wrapping material which is thereupon draped around the alternating filter disks and filter plugs, or by inserting filter disks between groups of axially aligned tobacco rod sections and filter plugs and thereupon wrapping adhesive-coated uniting bands therearound.

Aerosol coalescing filter and the like

Abstract: A filter structure comprises a foraminous relatively rigid support, a layer of filter material engaging said support and being coextensive therewith, and a layer of flexible foraminous material engaging a surface of the filter material opposite from the support. The flexible material is substantially coextensive with the filter material, and an arrangement is provided for pressing the flexible material into slight but uniform pressure engagement with the filter material at least during operation of the filter structure. In another embodiment of the invention a second layer of flexible foraminous material engages a surface of the support opposite from the filter material to facilitate drainage and to minimize reintrainment.

Method of making a sandblast mask

Abstract: A method of making a sandblast mask from a photopolymer layer including the step of forming a colored filter layer between the photopolymer layer and the workpiece to prevent light reflected from the workpiece from exposing the photopolymer layer.

Filter for prevention of microembolism during massive transfusions.

Abstract: This concern by cardiovascular surgeons stimulated thoughts of the possibility of pulmonary microembolization following the infusion of bank blood into the venous system. In 1965, Moore5 questioned whether accumulation of material in the lungs when many units of blood are rapidly transfused might cause impaired pulmonary function. Autopsies in another study6 revealed multiple pulmonary emboli in patients who developed pulmonary insufficiency following massive transfusion. Swank7 and Moseley and Dotys have shown that particulate aggregates increase in bank blood with the

High throughput filter having multiposition valve

Abstract: Filter for swimming pool water in which multiple operational modes including filtration, backwash and rinse modes are achieved with a valve structure affording positive sealing during operation, positive locking into mode, and adjustment between modes without frictionally wearing critical seals in the valve, and positive sealing at the waste discharge against air flow into the filter. The filter valve structure further employs large ports and direct flow passages to provide low pressure drop, even at very high flow rates through the filter, and a novel water distributor to avoid turbulence and undue disruption of the filter medium during filtration.

Vacuum filter with removable filter element

Abstract: Apparatus for performing laboratory vacuum filtration having a removable filter element is disclosed. The removable element comprises a porous disc having a groove formed in its periphery. The apparatus includes a funnel which has a cylindrically shaped upper wall and the porous disc is held within the wall of the funnel by an O-ring. The O-ring may further be used to hold a filter medium such as filter paper onto the porous disc. The filter apparatus further utilizes an elastomeric stopper which fits into the neck of a bottle or other filtrate container.

Antibodies to a DNA:RNA hybrid in systemic lupus erythematosus measured by a cellulose ester filter radioimmunoassay.

Abstract: Antibodies to a DNA:RNA Hybrid in Systemic Lupus Erythematosus measured by a Cellulose Ester Filter Radioimmunoassay

Multi-level, pleated filter array

Abstract: A multi-level, resin-impregnated, pleated, paper product filter assembly having spaced annular arrays of normally stable, pleats resiliently flexible circumferentially, a helical spring circumjacent between adjacent apices of the pleated arrays to resist collapse of paper product filters due to radial forces between adjacent filter levels and providing two-stage filtration in which the outer filter array comprises a filter pore size effecting first stage filtration of generally larger solids foreign matter, and the second or inner filter array provides second stage filtration of relatively finer foreign particles; in which perforated inner and outer cylindrical shells stabilize the filter cartridge or assembly in which the outer shell includes a plurality of spaced circumferentially disposed series of perforations to equalize pressure over the outer surface of the outer filter element; and in which an end cap and resilient seal combine with the outer and inner shells to coaxially clamp and insure against short-circuiting of the liquid being filtered.

Intravenous injection apparatus drip chamber having filter means and method of making same

Abstract: An intravenous injection apparatus drip chamber comprises a tubular plastic member having a lower wall with an outlet hole formed therethrough and defining an annular shoulder around said outlet hole. A filter means includes a flat metallic filter having raw outer edges which is disposed within a recess in the bottom of a plastic filter ring. The filter ring has a lower tapered portion which is ultrasonically fused to the annular shoulder on the lower wall of the drip chamber. The filter ring is also bonded to the outer periphery of the metallic filter.

Apparatus for cleaning filter plates and the like

Abstract: A stack of flat plates consisting of rectangular frames spanned by filter cloth, normally held together under pressure, is overlain by a rail extending lengthwise of the stack and carrying a transverse beam on which a carriage supports a cleaning unit introduceable from the side into the space between two separated filter plates. The unit comprises a pair of horizontal or vertical spray tubes, each extending over the full width or height of the filter cloth, which are vertically or horizontally movable with the aid of a pair of guide rollers riding on opposide edge portions of the frame when driven apart by a fluidoperated expander. The correct positioning of the beam with reference to the separated filter plates can be ascertained by a centering device adapted to be lowered into the intervening space, this device including two spreadable arms terminating in respective sensing rollers.

Charge-coupled-device analogue matched filters

Abstract: Charge-coupled-device shift registers are used to construct filters matched to both a 13-chip Barker-coded p-n sequence and a chirp signal with a time-bandwidth product of 10. The letter describes the design and fabrication of the devices, and presents preliminary operational characteristics of the filters. A 5 MHz chip rate for the Barker code filter is demonstrated

Replaceable element coolant filter

Abstract: A pleated paper filter element is adapted for use in an existing water filter housing for internal combustion engine cooling systems by means of a grommet that serves to seat the element and seal it around the housing outlet.

Encoding and decoding of color information

Abstract: Color information is recorded on a colorless substrate by having each color separation amplitude modulate a different spatial frequency carrier This is accomplished in a single exposure using an appropriate color-encoding filter The reconstruction of the color scene involves a point source projector with a color decoding mask The light output of the projector, for sources of a given brightness, is shown to be proportional to the total number of lines in the encoding filter The relatively, high efficiency of an encoded phase transparency is evaluated, and a decoding method is shown

On innovation sequence testing of the Kalman filter

Abstract: SequentiaUy proven statements are given showing that the whiteness of the innovation sequence of a steady-state Kalman filter is not a sufficient condition for the optimality of the filter. Simulation results are given which verify each of the statements. Definite conclusions are reached concerning the identification of a class of systems by using the output sequence.

Horizontal sync detector and video clamp circuit

Abstract: A composite video signal is coupled by way of a first path through a gated clamp circuit to one input of a gating circuit. The composite video signal is also coupled to a low-pass filter which removes high frequency energy in the composite video signal. Amplitude peaks in the video signal at the output of the low-pass filter cause an amplitude detector to develop voltage pulses during each one of the horizontal sync pulse intervals. In response to these voltage pulses, a strobe generator causes the gated clamp to operate and clamp the composite video signal to a reference voltage during the sync interval. In addition, the voltage pulse also causes a monostable multivibrator to generate a window pulse at a second input of the gating circuit, the window pulse having an interval sufficiently long to always encompass the trailing edge of the horizontal sync pulse. As a result, the gating circuit passes the trailing edge of the horizontal sync pulse in the composite video signal and blocks the voltage spikes present during the active region of the video signal.

Scintillation camera with improved resolution

Abstract: An Anger-type scintillation camera system fitted with a gamma ray filter between the object under study and the detector and an output signal filter of the signal funneling type which employs a non-linear array of signal filter windows to compensate for inherent non-linear spatial response characteristics in the camera system.

Rotating filter for wastewater biological purification

Abstract: The invention relates to a rotating filter for wastewater biological purification. The filter comprises at least one pack of parallel channels that are open at their extremities. The pack is rotated in the direction of development of the channels, so that it is periodically in contact with the wastewater and then with the atmospheric oxygen. As a consequence of this construction of the filter, its purifying capability is improved greatly.

Intensity spatial filter having non-uniformly spaced filter elements

Abstract: A spatial filtering system for inspecting integrated circuit photomasks, and the like. The system employs a spatial filter comprising a matrix-like array of opaque regions on a transparent field. Unlike prior art systems where the region-to-region spacing of the filter is uniform, in the instant invention the region-to-region spacing steadily increases from the centermost element outward according to a precise mathematical formula.