Abstract: A signature verification method operates by comparing the numerical values of parameters evaluated on a trial signature with stored reference data derived from previously entered reference signatures. The parameters include global features of the signature, and also include a stroke-direction code (SDC) of the signature. An SDC is derived by subdividing the signature into a sequence of time-ordered, spatially oriented line segments, each segment extending between a pair of discrete points along the signature. Each line segment has a stroke-direction value. The SDC is the ordered sequence of these stroke-direction values.

Abstract: An image classifier, which performs character recognition, receives input images and assigns each input image to one of a plurality of image classes. The image classifier includes plural class distribution maps, each based on a plurality of features evaluated on training images, and each representing those feature values that occur at least once among the training images belonging to the corresponding class. The image classifier further includes means for constructing a test map by evaluating the plurality of features on the input image. The image classifier further includes means for comparing the test map to the class distribution maps in order to identify which one of the class distribution maps has the least distance to the test map. At least one of the features is defined according to a rule that relates to the shapes of images of at least one image class.

Abstract: An optical probe microscope includes an optical fiber oriented in a vertical direction. The fiber has a tip that emits light onto a horizontal surface of a sample to be measured. This surface can have both desired and undesired departures from planarity. An electromechanical device for imparting dither motion to the fiber tip is superposed on another electromechanical device for imparting two-dimensional horizontal scanning motion to the fiber tip. The dither motion has a much higher frequency than that of the scanning motion. Between successive scannings, another device moves the sample itself from one horizontal position to another. A microscope receives the optical radiation either transmitted or reflected by the sample surface. The microscope forms a (magnified) image of this received optical radiation on the surface of an optical image position detector. The surface of this detector has a relatively large area compared with that of the (magnified) image.

Abstract: A method of operating a network by sharing resources associated with various classes among calls in the various classes according to a state dependent reservation parameter. Nominal amounts of one or more resources are allocated to each call class. When a call of a class of service operating in the network requires resources in excess of those allocated to the class, resources allocated to other classes of service are advantageously shared with the class of service. The sharing is based on a reservation parameter associated with the class of service of the call. The reservation parameter is advantageously a function of the network state. The role of the reservation parameter is to protect underloaded classes (i.e., those classes not using all of their allocated nominal capacity) from excessive borrowing by overloaded classes (i.e., classes using more than their allocated nominal capacity).

Abstract: Noise reducing circuits for electronic receiving instruments, such as telephone receivers in headsets or handsets that are used in noisy locations, provide compensation of the set's receiver unit-to-error microphone transfer function to enhance the noise reduction. Further circuits provide pre-conditioning of the incoming voice signal to make the noise cancellation more effective. The tendency of these noise cancelling circuits to oscillate is substantially lessened by added circuitry which rapidly detects onset of oscillation and momentarily reduces the noise cancellation without interrupting the incoming speech path altogether.

Abstract: An improved, single diaphragm SOD microphone uses acoustic filters to remove resonances associated with the ducting that guides the ambient sound pressure to the front and rear faces of a FOD microphone element. The microphone element communicates with respective front and rear chambers, two ports communicate with the front chamber via front conduits, and two ports communicate with the rear chamber via rear conduits. The microphone further comprises first and second side chambers for dissipating acoustic energy of undesired resonances. The first side chamber communicates with the front conduits, and the second side chamber communicates with the rear conduits. In specific embodiments of the invention, each of the side chambers comprises a branch conduit approximately equal in length to one-quarter wavelength of an undesired resonance. In certain embodiments, each of these branch conduits includes a small neck joining the branch conduit to its corresponding front or rear conduits.

Abstract: Dehydroxylated, silica-containing, glass surfaces are known to be at least partially terminated by strained siloxane rings. According to the invention, a surface of this kind is exposed to a selected silane compound or mixture of silane compounds under reaction-promoting conditions. The ensuing reaction results in opening of the strained siloxane rings, and termination of surface atoms by chemical species, such as organic or organosilicon species, having desirable properties. These species can be chosen to provide qualities such as hydrophobicity, or improved coupling to a polymeric coating.

Abstract: This invention involves a fiber probe device and a method of making it. The probe includes a relatively thick upper cylindrical portion, typically in the form of a solid right circular cylinder, terminating in a tapered portion that terminates in a relatively thin lower cylindrical portion, typically also in the form of a solid right circular cylinder, the lower portion having a width (diameter) in the approximate range of as little as approximately 0.05 .mu.m.

Abstract: An optical probe microscope includes an optical fiber oriented in a vertical direction. The fiber has a tip that emits light onto a horizontal surface of a sample to be measured. This surface can have both desired and undesired departures from planarity. An electromechanical device for imparting dither motion to the fiber tip is superposed on another electromechanical device for imparting two-dimensional horizontal scanning motion to the fiber tip. The dither motion has a much higher frequency than that of the scanning motion. Between successive scannings, another device moves the sample itself from one horizontal position to another. A microscope receives the optical radiation either transmitted or reflected by the sample surface. The microscope forms a (magnified) image of this received optical radiation on the surface of an optical image position detector. The surface of this detector has a relatively large area compared with that of the (magnified) image.

Abstract: This invention involves a fiber probe device and a method of making it. The probe includes a relatively thick upper cylindrical portion, typically in the form of a solid right circular cylinder, terminating in a tapered portion that terminates in a relatively thin lower cylindrical portion, typically also in the form of a solid right circular cylinder, the lower portion having a width (diameter) in the approximate range of as little as approximately 0.05 .mu.m.

Abstract: Noisy images of graphical or pictorial records, such as hand-written postal addresses, are cleaned by a method of analyzing the shapes of pixel clusters. According to such method, a set of structuring kernels is used to extract primitive shapes. The outcome of this extraction process is used to determine whether each pixel, in turn, is to be treated as part of a image element such as an alphanumeric character.

Abstract: A method for forming a grating in a photosensitive medium such as a photosensitive optical fiber. The method comprises impinging a pair of interfering, actinic beams onto the medium, and during the impinging step, advancing the illuminated portion of the interference pattern relative to the medium. The advancement is carried out without changing the phase, or registration, of the interference pattern. According to one embodiment of the invention, a grating having a spatially dependent period is produced by varying the wavelength or the intersection angle of the actinic beams during the advancement. According to a second embodiment of the invention, a grating having a spatially dependent refractive index perturbation is produced by varying the dose of actinic radiation received by the medium during the advancement.

Abstract: A passive fiber optic repeater bypass is provided which brings fault tolerance to repeatered fiber optic transmission systems. A fiber optic bypass provides an alternate signal path around failed repeaters. The bypass optical attenuation is set to ensure the bypass signal is sufficiently small so as not to interfere with the locally regenerated and transmitted signal, but sufficiently large to be received at the next repeater. In the event of a repeater failure, a repeater monitor disables the local laser transmitter allowing the bypass signal to be received at the next repeater.

Abstract: A device for transmitting radiation is provided. The device includes a glass optical waveguide having a core. A Bragg grating is at least partially formed within the core. Associated with the Bragg grating is a transmission spectrum that includes a band in which incident radiation is attenuated, the peak attenuation being at a wavelength .lambda.. The transmission spectrum of the Bragg grating is such that the full width at half maximum measured in transmission is greater than or equal to (1.5 nm/1558.5 nm) .lambda. and peak attenuation within the band is greater than or equal to 90% of full scale transmission. Attenuation exceeds 50% of the peak attenuation everywhere within the full width at half maximum of the transmission spectrum.

Abstract: A new method for the manufacture of glass films on substrates involves the flame reaction of an aerosol comprised of droplets of a solution containing all the precursors for the glass. A solution containing the precursors for all oxide components is atomized, and the resulting droplets are reacted in a flame to form spherical glass particles which are deposited on a heated substrate. By moving the substrate through the flame, a homogeneous deposit is achieved. Subsequent heat treatment in a furnace sinters the porous particle layer into a clear glass. The method has been successfully employed for the formation of sodium borosilicate glass films on silicon substrates and rare earth-doped multicomponent glass films for active devices.

Abstract: A heterojunction bipolar transistor in an integrated circuit has intrinsic and extrinsic base portions. The intrinsic base portion substantially comprises epitaxial silicon-germanium alloy. The extrinsic base portion substantially comprises polycrystalline material, and contains a distribution of ion-implanted impurities. An emitter overlies the intrinsic base portion, and a spacer at least partially overlies the emitter. The spacer overhangs the extrinsic base portion by at least a distance characteristic of lateral straggle of the ion-implanted impurities.

Abstract: The number of circuit path crossover points on boards mounting plural connected multichip modules is substantially reduced over the number that would otherwise be required. For 4-sided modules and boards, the modules are arranged on the board in such a way that their inter-connecting north-east-south-west ports are successively reordered to N-S-E-W. Additionally, further advantage in reducing crossover vias may be gained by combining the reordering with a phased rotation of the modules from their nominal congruent board position. For the 4-sided module, these expedients virtually eliminate crossover vias between the east and west ports. It also provides for all MCMs a ready common bus structure located at a common interior area of the mounting board, to which the E- and W-ports are oriented. The invention is applicable to a class of multi-sided, multi-chip modules on boards with a like number of sides.

Abstract: In a method for cleaning using terpene compositions, the generation of harmful precipitates is substantially eliminated or significantly reduced by adding a polar solvent, such as isopropyl alcohol, to the terpene composition. One to twenty percent of the cleaning composition should be alcohol, although it is preferred that it be in the five to fifteen percent range. The upper limit reflects primarily the desire to reduce the flammability of the solvent. Alternatively, the electronic devices can be rinsed with a terpene, alcohol mixture, but this alternative is much less preferred because of the flammability problem.

Abstract: An optical image correlator includes a photorefractive medium for recording an interference pattern that corresponds to the Fourier transform of an input image or the multiplicative product of the Fourier transforms of two respective input images. In contrast to correlators of the prior art, the correlator described here includes a semi-insulating, multiple quantum well device as the photorefractive medium.