Abstract: In order to establish a low-electrical resistance between two wires, a heat-shrinkable hollow tube is prepared. Three or more small-diameter conductors are attached to the inner surface of the hollow tube, such as by use of an epoxy adhesive. These conductors run parallel to the axis of the tube along its entire length. Each of the two wires is inserted into an opposite end of the tube. The tube is then heated to a sufficient temperature, such that when it cools it collapses and grasps both of the wires firmly, whereby the resulting electrical conductance between them (aided by the conductors) is enhanced.

Abstract: The present invention is directed to a semiconductor waveguiding structure which includes a) a first semiconductor waveguiding layer formed on a substrate, b) a barrier layer that is formed on the first semiconductor waveguiding layer, and that is resistant to a selected etchant, and c) a second semiconductor waveguiding layer that is etched using the selected etchant such that its width is tapered along its length to a pointed edge. A separate etching of the first semiconductor layer is performed to form each sidewall of the first semiconductor layer. The intersection of those sidewalls defines the pointed edge which has a radius of curvature of less than 500 Angstroms.

Abstract: A phase-looked loop circuit with holdover mode is formed utilizing a primary and secondary phase-locked loop circuits. Each loop circuit comprises a phase detector, loop filter, VCXO and frequency divider. The secondary loop is configured such that its output is very stable. The primary loop is phase-locked on a received reference clock signal and the second loop is phase locked on the output of the primary loop. The scaled output of the secondary loop being parallel to the reference clock signal. If the incoming reference signal is interrupted or lost the circuit is switched to a holdover mode where the input of the primary loop is switched to the stable scaled output of the secondary loop. In holdover mode, the output of the primary loop is phase-looked to the stable output of the secondary loop. When the reference clock signal is reestablished, the input of the primary loop is switched back to the reference clock signal.

Abstract: Bidirectional transmission over a single optical fiber is obtained in an optical communications system by using a three port circulator in customer premises equipment together with an optical fiber amplifier and a narrow band filter. The fiber amplifier can be locally or remotely pumped. The acousto-optic modulator is advantageously used because it reduces the coherent Rayleigh noise by detuning upstream and downstream wavelengths.

Abstract: Look-ahead control techniques and a variable attenuator are used to solve the known problem of differential attenuation of photonic intensities between time slots are delayed differently in delay paths that have different losses which optical time slot interchangers have. The result of the look-ahead control techniques and variable attenuator is a data frame in which the widely varying photonic intensities are equalized to a substantially similar level, thereby greatly reducing the bit error rate of the downstream receiver/demodulator.

Abstract: A method and apparatus for visually displaying structural characteristics of a large database for visualizing areas where new developments may be added, or finding places where old developments may need to be re-structured or replaced. This method and apparatus shows the entire structure without showing the entire semantics, which would be too much information. Semantic information is available in other windows that can be opened after the focus of the analysis is selected. After selection, the semantic information is displayed in a focused manner also. This is accomplished by referencing the selected relation to the location of that relation in the database specification or in the relational data base management system (RDBM) application code.

Abstract: Articles being graphical input patterns are sorted by a pattern-recognition machine that includes a data base of prototype patterns, each labeled with its respective class. The sorting method includes stops of storing input patterns in the pattern-recognition machine and classifying the stored input patterns. The classification is performed by calculating at least two distance functions between input patterns and prototype patterns. The distance functions belong to a hierarchy of distance functions that vary in the degree to which they are computationally intensive, and concomitantly, in their accuracy. Overall computational requirements are reduced by using less computationally intensive distance functions to preliminary filter out those prototype patterns that are farthest from the input pattern.

Abstract: In order for neural network technology to make useful determinations of the identity of letters and numbers that are processed in real time at a postal service sorting center, it is necessary for the neural network to "learn" to recognize accurately the many shapes and sizes in which each letter or number are formed on the address surface of the envelope by postal service users. It has been realized that accuracy in the recognition of many letters and numbers is not appreciably sacrificed if the neural network is instructed to identify those characteristics of each letter or number which are in the category "invariant." Then, rather than requiring the neural network to recognize all gradations of shape, location, size, etc. of the identified invariant characteristic, a generalized and bounded description of the invariant segments is used which requires far less inputting of sample data and less processing of information relating to an unknown letter or number.

Abstract: Portable computing and communications devices are connected with other, typically fixed devices via the use of a capacitive data connector. Each of the two mating sections of the connector includes a set of coupling plates. When the two sections are brought into contact, the coupling plates form capacitors across which data signals can be passed. Circuitry driving each section of the data connector is such as to create a bidirectional signaling path, thereby providing a connection which is functionally equivalent to an ohmic connection. Signals that are typically passed across data connectors on individual parallel leads are, in the present data connector, serialized, passed across the connector in that form and connected back to parallel form on the other side of the connection. Each section of the connector illustrately includes a permanent magnet to draw and hold the two sections in alignment, thereby providing a connector which is self-aligning.

Abstract: A passive optical attenuating device comprises an optical waveguide adapted to receive optical radiation and absorb, along its length, at least 0.2 dB/m of the optical radiation. The waveguide section may be coupled to a low-loss optical fiber so as to receive an optical signal to be attenuated therefrom. In accordance with one aspect of the invention, at least one region of the waveguide is doped with a transition metal to achieve a pre-selected absorptivity per unit length so that a controlled degree of attenuation can be achieved.

Abstract: A backup file system which can be used without modification of application programs, the operating system, or the hardware. The backup file system is implemented by means of a dynamically-linkable replacement library and user-level processes on a primary computer system and a backup computer system. The dynamically-linkable replacement library has the same interfaces as a standard dynamically-linkable library of file operations. The functions in the replacement library perform the same file operations as their counterparts in the standard library; in addition, they send messages specifying the just-performed operation to a user-level process on the backup computer system. The user-level process executes the operation specified in the message on a backup file in the backup computer system. The files to be backed up are specified by identifying subtrees in the namespace of the primary file system; the subtrees make up a user-defined namespace.

Abstract: A frequency synthesizer circuit for the front end of an RF system. The frequency synthesizer uses two pulse-swallow phase-locked loops in a synthesizer architecture that produces an output frequency that is a function of the two reference frequencies used as inputs into the two phase-locked loops. As a result, the frequency synthesizer can be incremented in steps equal to the differential of the reference frequencies of the two phase-locked loops, while the frequency outputs of each of the phase-locked loops can be incremented in much larger steps. This enables the two phase-locked loops to employ relatively large bandwidths, thereby achieving a faster signal lock as well as a better suppression of the voltage controlled oscillator (VCO) phase noise in each loop. The use of a dual loop synthesizer architecture allows for feedback correction of the VCO phase noise outside the loop bandwidth.

Abstract: An improved method for correcting spelling errors in text wherein candidate expressions for replacing a misspelled word are assigned probability functions. The misspelled word can be replaced automatically with the candidate expression having the highest probability function or candidate expressions can be displayed to a user in rank order of their probability functions for the user to make a choice. The probability function for a candidate expression is based on (1) the probability of occurrence of the candidate expression appearing in text and/or (2) the probability of occurrence of the particular typographical modification needed to convert the candidate expression into the misspelled word.

Abstract: The offset associated with mismatch of a pair of input devices in comparators used in applications such as flash converters is eliminated by using only one input device or transconductance circuit, time-shared between the input and reference signals. The input device converts each signal in succession into a current. A current copier stores one of these currents while the input device produces the other current, and the two currents are then compared by connecting them to a common node. The comparator includes a first switch for switching between an input and reference nodes, and an input device which receives a reference signal from the reference node during a first comparison cycle, receives an input signal from the input node during a second comparison cycle, and converts the input signal and the reference signal to input and reference currents, respectively.

Abstract: A converter for enhancing power factor utilizes a line sense winding magnetically coupled to sense a voltage across a line inductor in the input of a high power factor power converter. This winding in the illustrative embodiment is typically a single turn. This winding provides a measurement of the derivative (with respect to time) of the line current, and a specially designed integrator connected to the winding provides the estimate of the line current. An integrator is operative to accurately estimate the current by using known properties of this current to prevent mismeasurement due to reconstructing the "constant of integration" and any small biases in the integrator which normally cause errors.

Abstract: A telecommunications network including a plurality of local exchanges or switching systems, each local switch supporting at least one customer line accessed by customer premise equipment (CPE) such as telephone station sets or multimedia stations. The local switches are connected to one another directly and through tandem switches to create the network. A data base is associated with each local exchange, or with a limited number of local exchanges, and is accessed by the local exchange to provide information for controlling the routing of a call. Each data base contains rate information for the service providers offering competitive services. Such rate information includes the service providers' basic rate structures, time of day discounts, group calling plans, usage discounts and the like. The switching system, in response to information provided by the data base, automatically routes the call to the lowest cost service provider based on this rate information.

Abstract: A black matrix structure suitable for use in an active matrix liquid crystal display is described. The novel antireflective black matrix comprises successive layers of zinc oxide, molybdenum, a second layer of zinc oxide and a molybdenum mirror, all of which are deposited upon the front surface of a glass substrate member. An alternative structure includes the same sequence of layering on the back surface of the molybdenum mirror. The described black matrixes reduce reflectance of incident light to less than 0.5%. A technique for the preparation of the described structure involving cathodic sputtering is also described.

Abstract: A method for aligning and soldering a first device (11) to a substrate (16) comprises the steps of providing a plurality of solder elements (17) between the first device and the substrate, aligning the first device, and then reflowing and cooling the solder elements to bond the first device to the substrate. The improvement comprises, first, reflowing only a first group of solder elements and then cooling the elements of the first group, thereby to tack the first device to the substrate. Thereafter, we reflow only a second group of the plurality of solder elements and cool the second group, thereby to provide a more secure bond between the device and the substrate without interfering with the alignment of the first device. This method reduces the amount of energy needed for each reflow step, thereby reducing stresses and maintaining better alignment.

Abstract: A video system that captures telephone number data encoded into video signals transmitted over a video network to at least one display device is disclosed. Video signals are received that contain an escape sequence demarcating telephone number data. The system identifies the escape sequence, and captures the telephone number data. Upon command, dialing data corresponding to the telephone number data are transmitted over a telephone network to initiate a telephone call to the desired party.