Abstract: A pseudo-random binary sequence generator comprises at least one shift register (S, T) arranged in a recirculating loop and having a plurality of logic gates (G) for logically combining the outputs of selected stages of the register to provide a pseudo-random sequence, and a multiplexer (M), having a p data inputs and q address inputs all connected to selected shift register stages, and which selects at any instant one of the p data input bits in accordance with the q-bit address word to provide the generator output. The number s of logic gates is especially high and is related to the total number r of shift register stages (r>p+q) by the expression: 2.sup.s .gtoreq.r.sup.2. Some of the shift register stages of the or each shift register are connected to selected data inputs of the multiplexer and others of the stages of the same shift register are connected to selected address inputs of the multiplexer.

Abstract: A data processing system in which macroinstructions are decoded to provide a sequence of microinstructions comprising one or more microroutines. If a fault condition occurs, the currently executing microinstruction of a sequence thereof is interrupted, while the fault is being handled. When the fault has been resolved, execution of the interrupted microinstruction resumes. If the fault cannot be resolved the sequence of microinstructions is permanently aborted. The process of interrupting the sequence and resuming operation at the interrupted microinstruction is essentially invisible to the microprogram.

Abstract: A channel propagation simulator simulates a multi-diversity branch signal channel, which simulator uses in a preferred embodiment appropriate filter means, such as a plurality of tapped delay lines 11, 14, each capable of representing the impulse response of a diversity branch by means of correlated tap multipliers 12, 12A, 15, 15A . . . 15N, i.e., multipliers using correlated weighting signals 12', 12'A, 15', 15'A . . . 15'N as supplied from a matrix weighting correlator 19. The correlated weighted signals are combined for each diversity branch by suitable summation circuits 13, 16 to provide the diversity branch simulated outputs. By using correlated weighting signals, the simulator can more accurately reproduces the statistical behavior of a given communications link and verify that a given modem will satisfy the communication link specifications.

Abstract: A system for providing a spectrophotometric analysis of a plurality of fluid samples, the system including a spectrophotometer having a low pressure flow cell and an automatic injector device which stores the fluid samples without exposure to the atmosphere and injects the samples successively at low pressure into the flow cell where they can be scanned to produce scanned data for processing. The system prevents the scanning of each fluid sample until the injection thereof has been completed, the processing of scanned data for each fluid sample being performed substantially simultaneously with the injection of the next successive fluid sample into the flow cell.

Abstract: An adaptive filter (11) for use in a diversity receiver system (10) which includes circuitry (23, 24, 25, 26, 34) for determining the strongest received diversity signal or group of signals at each of a plurality of time delays or group of time delays and circuitry (27, 28, 29, 30, 31, 34) for calculating a weighting signal and for weighting only the strongest received diversity signal or group of signals at each of the time delays or group of time delays, the other received diversity signals at each time delay thereby being in effect weighted by zero. The weighted signals are then combined in a delay line (32, 33) having a plurality of taps at such time delays to produce an output receiver signal. In a particular embodiment, for example, the received signals are complex signals and the weights used for the strongest received diversity signal at each time delay are quantized weights selected from the group .+-.1.+-.j.

Abstract: A digital computer system having a memory system organized into objects for storing data and a processor for processing data in response to instructions. An object identifier and an access control list are associated with each object. The memory system responds to logical addresses for data which specify the object containing the data and the offset of the data in the object and to a current subject for which the processor is referencing the data. The memory system performs a memory operation for the processor only if the access control list for the object specified by the logical address allows the current subject to perform the desired memory operation. The objects include procedure objects and data objects. The procedure objects contain procedures including the instructions and name tables associated with the procedures. The instructions contain operations codes and names representing data. Each name corresponds to a name table entry in the name table associated with the procedure.

Abstract: Pipes or tubes, for example, in heat exchangers, can be cleaned internally using a water hammer shock wave with a relatively incompressible pig which travels at high velocity and a flushing liquid. FIG. 1 illustrates the use of launcher (14) to apply a very rapid pressure build-up by means of a liquid to one end of a pig located in a tube (11) to be cleaned.

Abstract: Pipes, tubes and the like, for example, in heat exchangers, can be cleaned internally using sonic energy, a relatively incompressible pig and a flushing liquid.The flushing liquid is supplied via a pressure outlet from a quick operating valve to one or more launchers for launching pigs. The launchers are mounted on either an x-y frame movable support or a rotary axis adapter and radially movable support for positioning the launchers with respect to the ends of the tubes to be cleaned.

Abstract: The apparatus comprises a manually operable device producing pulses which directly or after integration, determine the rate of replay of the digital audio. These pulses are counted by a counter. Each pulse corresponds to 1.5/500 s audio. The counter is reset at the rate F.sub.s /2048 where f.sub.s is the constant output sampling rate and its contents are held in a latch whose contents are inversely proportional to the replay sampling period. Adders add the contents of the counter into overflowing accumulators and clocked at the KHz fixed sampling rate f.sub.s and 128 times this rate respectively. The number of SPR of the first accumulator represents the sample displacement while the MSB of the second accumulator provides the replay clock. The sample displacement (d) represents the displacement between an output sample and an input sample and controls a two stage interpolation by way of a finite impulse response filter and a linear interpolating filter.

Abstract: A technique for forming a composite mixture of materials, at least one of which is a metal, in which each of the materials is supplied in a molten or slurry state to separate channels. The materials are then supplied to one or more mixing regions substantially simultaneously where they are caused to impinge upon each other to form a composite mixture thereof. The composite mixture is supplied to one or more cooling regions for casting, the supplying of the materials to the separate channels, the forming of the composite mixture and the casting being performed in a substantially continuous operation.

Abstract: A dental materials dispenser is disclosed with an actuator operated by an electronically controlled motor. The dispenser may be used in conjunction with a disposable cartridge removably mountable in the dispenser. The cartridge includes a hollow needle comprising an integral heating element along its length. An electronic controller regulates the speed and direction of the motor and the current delivered to the heating element.

Abstract: Spatial light modulators which use a substrate having a buried channel charge-coupled device (CCD) formed therein, wherein the amount of charge in the charge storage wells associated with the electrodes of the CCD is controlled by an electrically or optically addressed data signal. The level of charge in such charge storage wells controls the electric field beneath the electrodes so that the intensity of electromagnetic energy (e.g., light) directed through the CCD is spatially modulated by the charge levels in the charge storage wells in accordance with the Franz-Keldysh electroabsorption effect.

Abstract: A modem in which the transmitter uses spectrum spreading techniques applied to sequentially supplied input bits, a first group thereof having one spread spectrum sequence characteristic and a second group thereof having a different spread spectrum sequence characteristic, the spread spectrum bits being modulated and transmitted. The receiver generates complex samples of the received modulated signal at a baseband frequency and uses a detector for providing signal samples of the complex samples which are time delayed relative to each other. A selected number of the time delayed samples are de-spread and demodulated and the de-spread and demodulated samples are then combined to form a demodulated receiver output signal.

Abstract: A pair of elements for providing slidable electrical contact therebetween wherein the contact surface of at least one of the elements comprises a plurality of contact portions and a plurality of depressed portions in between the contact portions so that wear particles which are generated between their contact surfaces as the elements are moved relative to each other are effectively swept from between the contact surfaces into the depressed portions where they are entrapped. Such operation tends to maintain a low electrical resistance between the elements over many cycles of use.

Abstract: A radome shutter structure for preventing the transmission of electromagnetic energy within a selected frequency range and for permitting the transmission of energy outside such frequency range during a first mode of operation and for permitting the transmission of electromagnetic energy over a relatively wide frequency range which includes such selected frequency range during a second mode of operation. The structure includes an insulative substrate having a symmetrical array of metallized regions, each region preferably in the form of a Jerusalem Cross having discontinuous arms interconnected by diode elements which are placed in a conductive state in the first mode of operation and in a non-conductive state in the second mode of operation.

Abstract: A collision avoidance system for preventing collision between vehicles capable of moving along the same general path, which system includes a vehicle having a device for emitting optical pulses and another vehicle having a detector which uses an optical scanner defining a substantially triangular scan field. The detector responds to the emitted optical pulses and determines the range between the vehicles and the closing speed between them. An alarm system responds to the closing speed determination to permit evasive action to be taken when the closing speed exceeds a selected value.

Abstract: Three fixed reference stations having known positions comprise Omega receivers. Phase measurements made at all three stations are assembled at a master station, utilizing landlines or radio links and, using the known positions of the stations, a central processing unit calculates not merely the offset of the master station as measured from the true position but also the errors in the azimuths of the propagation directions of the received signals. The position measurement of a vehicle with an Omega receiver is corrected on the basis of the offset and also the errors in the said azimuths. Sufficient accuracy is achieved for finding the position of land based vehicles whose position may be calculated subject to the corrections in the master station on the basis of raw data transmitted to the master station over a link. Alternatively the azimuth corrections may be transmitted to the vehicle over the link. Two fixed stations suffice if they can measure absolute phase.

Abstract: Video signals (Y,U,V) from a telecine machine are accompanied by a blemish signal (D) (obtained for example by infra-red scanning of a color film) indicating the presence of scratches, dirt etc. This controls a switch (22) to substitute information from another part of the film (e.g. the previous frame, from a frame store 33). To prevent substitution with information also containing blemishes, the blemish signal in respect of the substitute information is made available (flag store 36) to suppress the substitution and switch to an alternative source such as a interpolator (31). The use of a movement detector, (not shown) to suppress substitution from another frame when motion occurs, is also described. The circuitry can be adapted for use in conjunction with a videotape dropout detector.

Abstract: A data processing system in which macroinstructions are decoded to provide a sequence of microinstructions comprising one or more microroutines. A stack storage means stores data for use in such microroutines. The final microinstruction of the microroutines is a request to retrieve or remove data from the stack. When no data is present therein (the stack is empty) a new macroinstruction is requested and when data is present in the stack the microroutine returns to another mircoroutine in which it is acting as a micro-subsroutine to permit continuation of the other microroutine.

Abstract: A structure for use in determining the amount of radiation, e.g., X-ray radiation, received at one or more selected regions of an object, which structure includes a housing having front and rear covers and an image producing component, e.g., an X-ray film and one or more scintillating screens associated therewith positioned within the housing in alignment with such one or more regions. One or more detector arrays are fixedly positioned with respect to the housing in alignment with the image producing component and the one or more detector arrays respond to the one or more images produced to provide one or more output signals the values of which can be used to determine the amount of radiation received by the selected regions of the object.