Abstract: A wheelbarrow for carrying materials that includes a container, a pair of handles extending rearwardly from the container to control movement of the wheelbarrow and a pair of legs extending downwardly from the container to contact the ground. The wheel also has a barrel shaped wheel located at a predetermined location near the front end of the container. The wheelbarrow is self-balanced by strategically positioning the barrel-shaped wheel under and a little forward the center of gravity of the wheelbarrow; that is, the contact point of the wheel with the ground is slightly offset forwardly underneath the center of gravity of the wheelbarrow so that lifting, pushing and tilting requires minimal force and allows for superior control and maneuverability. Due to the shape and width of the wheel, during turns, the center of gravity of the wheelbarrows remains vertically, stably and near the point of contact of the wheel with the ground.

Abstract: A wheelbarrow for carrying materials that includes a container, a pair of handles extending rearwardly from the container to control movement of the wheelbarrow and a pair of legs extending downwardly from the container to contact the ground. The wheel also has a barrel shaped wheel located at a predetermined location near the front end of the container. The wheelbarrow is self-balanced by strategically positioning the barrel-shaped wheel under and a little forward the center of gravity of the wheelbarrow; that is, the contact point of the wheel with the ground is slightly offset forwardly underneath the center of gravity of the wheelbarrow so that lifting, pushing and tilting requires minimal force and allows for superior control and maneuverability. Due to the shape and width of the wheel, during turns, the center of gravity of the wheelbarrows remains vertically, stably and near the point of contact of the wheel with the ground.

Abstract: A method for determining a quality indication, such as a bit error rate or a signal to noise ratio, of a photonic signal is described. The photonic signal is sampled, and then an estimated quality indication, such as the bit error rate, is calculated utilizing statisical analysis of the sampled photonic signal.

Abstract: A method for determining a quality indication, such as a bit error rate or a signal to noise ratio, of a photonic signal is described. The photonic signal is sampled, and then an estimated quality indication, such as the bit error rate, is calculated utilizing statisical analysis of the sampled photonic signal.

Abstract: An optical pattern detector in accordance with the principles of the present invention includes an optical sensor configured to sense a plurality of optical signals, an optical summer configured to receive and sum the sensed optical signals, and a sampler configured to sample the summed optical signals. The pattern detector may be configured to receive serial or parallel binary optical signals and, with various weightings of the sensed optical signals, may operate as an optical digital to analog converter, automatically decoding binary digital optical signals.

Abstract: A temperature-compensated optical grating is fed an optical probe signal of a predetermined wavelength. An optical detector having a plurality of apertures for receiving an optical signal is positioned to detect a probe light signal from the grating and to detect the deflection of the probe light signal from a preferred location. The detector provides an indication of the deflection to a controller which operates a temperature adjustment device, such as a fan or thermoelectric cooler to adjust the temperature of the grating in a direction which reduces the deflection.

Abstract: A temperature-compensated optical grating is fed an optical probe signal of a predetermined wavelength. An optical detector having a plurality of apertures for receiving an optical signal is positioned to detect a probe light signal from the grating and to detect the deflection of the probe light signal from a preferred location. The detector provides an indication of the deflection to a controller which operates a temperature adjustment device, such as a fan or thermoelectric cooler to adjust the temperature of the grating in a direction which reduces the deflection.

Abstract: An optical pattern detector in accordance with the principles of the present invention includes an optical sensor configured to sense a plurality of optical signals, an optical summer configured to receive and sum the sensed optical signals, and a sampler configured to sample the summed optical signals. The pattern detector may be configured to receive serial or parallel binary optical signals and, with various weightings of the sensed optical signals, may operate as an optical digital to analog converter, automatically decoding binary digital optical signals.

Abstract: Data signals from two or more different communication networks conforming to one or more different transmission protocols are re-formatted into an internal data format for purposes of routing the data signals. The internal format has one or more fields corresponding to terminated overhead data for storing payload data. In one embodiment, a switching system has a network-independent switch and two or more network-dependent port units. Each port unit is configured to interface with a different communication network and to convert data signals between the transmission protocol of the corresponding communication network and the internal format. The switch receives and routes the data signals in the internal format and transmits the routed data signals back to the appropriate port units for re-formatting for transmission to the corresponding communication networks.

Abstract: A memory device, a method of content-addressing a memory device to validate an incoming pattern and an Asynchronous Transfer Mode (ATM) communication switching system incorporating the device or the method. In one embodiment, the device includes: (1) a validation random access memory (RAM) having a plurality of addressable locations therein, the addressable locations containing validation indicators corresponding to patterns that have been programed into the validation RAM and (2) circuitry, coupled to the validation RAM, that provides an incoming pattern to the validation RAM and retrieves a corresponding validation indicator from the validation RAM, the validation indicator indicating whether the incoming pattern had been programed into the validation RAM. The memory device thereby functions as a content-addressable memory (CAM).

Abstract: A switch for selectively cross-coupling first and second input lines to first and second output lines. The switch includes: (1) a waveguide having a cavity for containing signals, (2) first and second wireless transmitters that radiate signals received from the first ands second input lines, respectively, within the cavity, (3) first and second wireless receivers that selectively receive the signals from the cavity and provide the signals to the first and second output lines, and (4) a switch controller that controls the at least some of the first and second wireless transmitters and receivers. The first and second input lines are selectively couplable to the first and second output lines. The waveguide, wireless transmitters and wireless receivers cooperate to provide a fabricless cross-connect within the switch.

Abstract: A communication network called a bidirectional mesh network (MSN), also called bi-MSN, is described. The bi-MSN includes a plurality of first communication loops (horizontal loops) each comprising a plurality of nodes interconnected to one another by bidirectional communication links. The bi-MSN also includes a plurality of second communication loops (vertical loops) each comprising a plurality of nodes interconnected to one another by bidirectional communication links. Each second communication loop is connected to each first communication loop at a node which is common to both the second communication loop and the first communication loop. This common node (and, in fact, each node in the bi-MSN) includes a switch to transfer packets from the first communication loop to the second communication loop, and vice versa, as a function of destination addresses contained in the packets.

Abstract: A global satellite communication network is described. The global satellite communication network comprises a plurality of polar communication loops and a plurality of longitudinal communication loops. The polar and longitudinal communication loops are formed in three dimensional space. Each polar communication loop includes a plurality of nodes each bidirectionally communicating with adjacent communicating nodes in the polar communication loops. Each longitudinal communication loop includes a plurality of nodes each bidirectionally communicating with adjacent communicating nodes in the longitudinal communication loops. Each longitudinal communication loop is in communication with each polar communication loop via a node which is common to both the longitudinal communication loop and the polar communication loop.

Abstract: A process for producing a parallel processor system having the minimum number of microprocessors necessary execute in real time a set of tasks of a multi-tasking application such that execution of an activity of a first task is followed by execution of an activity of a second task. The process includes the step of selecting an initial number of microprocessors for executing the application in real-time. The selecting step includes placing in a first column of a matrix all real-time constrained tasks specific to the application and associating a row of dependent tasks with each task placed in the first column of the matrix to define a plurality of task subsets, each subset incorporating a maximum number of intradependent tasks and a minimum number of interdependent tasks and the number of subsets corresponding to the initial number of microprocessors. The inventive process further includes the steps of listing dependencies between rows in a second column of the matrix, assigning a priority p.sub.

Abstract: Disclosed is a circuit which allows a digital loop carrier remote terminal to communicate with a local digital switch having a TR8 interface. The circuit includes a pair of microprocessors and time slot interchangers which multiplex, demultiplex and distribute the data fields associated with the interface.

Abstract: A network is described which has a Manhattan Street architecture that is implemented using a token ring system, such as the fiber distributed data interface, with the primary and secondary rings representing vertical and horizontal lines, respectively.

Abstract: A programmable digital controller has an address matrix memory (20) and an instruction matrix memory (10). The address memory stores address words each having the address of the first sample and the number of samples in a unique group of samples. Unique groups of samples are sequentially stored in an instruction matrix memory. Each column of the instruction memory has data bits for regenerating an instruction set for controlling any one of many apparatus or processes. Each row of the instruction memory has a sample from each instruction set. In response to an enabling signal, the words from the address memory are sequentially read, interpreted, and the samples from the instruction memory caused to be read and for reconstructing the instruction set.

Abstract: A method for optically determining the ratio of Poisson's ratio to modulus of elasticity for optically isotropic and optically anisotropic transparent materials and then for determining the stress-optical constants for such materials. A collimated monochromatic light beam is directed at the tip of a crack in a loaded thin plate specimen of the material and the diameters of the resulting transmitted and reflected caustics are measured at points equidistant from the specimen. The light beam also is directed to an uncracked region in a loaded thin plate specimen of the material and the number of displaced fringe reflected on a screen are counted for a predetermined change in loading. The ratio of Poisson's ratio to modulus of elasticity and the stress-optical constants are determined from the thickness of the specimen, the displaced fringe count, the wavelength of the light beam and the ratio of the caustic diameters.

Abstract: A method for optically determining the stress-optical constants of optically isotropic and anisotropic materials. A collimated beam of monochromatic light is directed at the tip of a crack in a thin plate specimen under plane-stress from a direction substantially perpendicular to the surface of the specimen and to the direction of the stress. Reflected and transmitted stress-optical constants are determined from a ratio of the diameters of transmitted and reflected caustics from the specimen and the known Poisson's ratio and modulus of elasticity for the specimen.