Abstract: A method for authenticating, by a second user, the identity of a first user, that includes a challenge communication from the second user to the first user, a response communication from the first user to the second user, and a verification by the second user, includes the steps: selection by the first user of a private key f in a ring R and a public key that includes ?(f) in a ring B that is mapped from f using the ring homomorphism ?: R?B, and publication by the first user of the public key; generation of the challenge communication by the second user that includes selection of a challenge c in the ring R; generation of the response communication by the first user that includes computation of a response comprising h in the ring R, where h is a function of c and f; and performing of a verification by the second user that includes determination of ?(c) from c, ?(h) from h, and an evaluation that depends on ?(h), ?(c) and ?(f).

Abstract: A method is disclosed for downhole determination of the resistivity of fluids from formations surrounding an earth borehole, including the following steps: providing a formation testing logging device that includes a coil and a flow line passing axially through the coil; determining a reference quality factor of the coil; positioning the formation testing device in the borehole, and causing formation fluid to flow through the flow line; measuring the quality factor of the coil with formation fluid in the flow line; and determining the resistivity of the formation fluid in the flow line as a function of the measured quality factor and the reference quality factor.

Abstract: An apparatus for displaying images represented by electronic image information, that includes a light source and a reflective light modulator for optically modulating, with the image information, light from the light source to obtain a diffraction pattern that depends on the image information. An optical system is provided for converting the diffraction pattern into an image, and projection optics are provided for projecting the image obtained with the optical system. The optical system includes an array of schlieren bars and a focusing reflector.

Abstract: A technique for producing electronic video signals representative of color images of a scene, includes the following steps: providing a luminance sensor and a color sensor having a color filter thereover; providing a pellicle beamsplitter, and providing a motion picture film camera type of lens system that focuses light from the image, via the beamsplitter, onto the luminance sensor and the color sensor; and producing electronic video signals from outputs of the luminance sensor and the color sensor. The pellicle can be ultrasonically excited to effect optical prefiltering.

Abstract: A technique for producing electronic video signals representative of color images of a scene, includes the following steps: providing a luminance sensor and a color sensor having a color filter thereover; providing a beamsplitter, and providing a motion picture film camera type of lens system that focuses light from the image, via the beamsplitter, onto the luminance sensor and the color sensor; and producing electronic video signals from outputs of the luminance sensor and the color sensor.

Abstract: A method of forming a semiconductor device includes the following steps: providing a plurality of semiconductor layers; providing means for coupling signals to and/or from layers of the device; providing a layer of quantum dots disposed between adjacent layers of the device; and providing an auxiliary layer disposed in one of the adjacent layers, and spaced from the layer of quantum dots, the auxiliary layer being operative to communicate carriers with the layer of quantum dots.

Abstract: A method of forming a semiconductor device includes the following steps: providing a plurality of semiconductor layers; providing means for coupling signals to and/or from layers of the device; providing a quantum well disposed between adjacent layers of the device; and providing a layer of quantum dots disposed in one of the adjacent layers, and spaced from the quantum well, whereby carriers can tunnel in either direction between the quantum well and the quantum dots.

Abstract: An ultrasonic imaging technique and apparatus with a portable scanning head. In one form of the scanning head, a reflective scanner is provided with a variable focus, and in another form the scanning head has several reflective facts of respectively different focal lengths.

Abstract: A method of operating on a workpiece comprises causing relative movement between the workpiece and a power beam in a traverse direction so as to expose a series of locations on the workpiece to the power beam. At each location the power beam is caused to move relative to the workpiece in a predetermined manner having a component transverse to the traverse direction, and workpiece material is melted and displaced by the power beam so as to form a cavity or hole.

Abstract: A method of encoding and decoding an image includes the following steps: subsampling the image to obtain a plural number of subsampled frames of spatially offset image-representative signals; transforming each of the subsampled frames to obtain a corresponding number of frames of transform coefficient-representative signals; forming vector-representative signals from corresponding coefficient-representative signals of the respective frames of coefficient-representative signals; transforming the vector-representative signals; quantizing the transformed vector-representative signals to obtain encoded signals; transmitting the encoded signals; receiving the transmitted encoded signals; and decoding the encoded signals to obtain a recovered version of the image.

Abstract: A method for interactive training of a user, includes the following steps: providing one or more stimulus/response training modules for user selection, each of the modules comprising a sequence of several stimulus/response sessions; for a selected module, scheduling the sessions at time intervals; for each of the sessions, implementing a sequence of one or more incidents, each incident comprising presenting to the user a visual and/or audio stimulus requiring a verbose response; evaluating each response for acceptability, and informing the user of any unacceptable response; and terminating a module when the scheduled sessions have been performed.

Abstract: A display panel which employs semiconductor light sources, fiber optics, liquid crystal and a switching matrix to obtain efficient display.

Abstract: A method for encoding and decoding an input signal, includes the following steps: applying a transform to the input signal to obtain a transformed signal; quantizing the transformed signal to obtain a sequence of quantized values, the quantized values being representable in the form of ordered binary bits; for each order of said binary bits, encoding a bit plane of the sequence using (run, end) coding to obtain encoded values; and decoding the encoded values to recover the input signal.

Abstract: A wireless pen apparatus for producing signals representative of writing by a user, including: a wireless pen; a removable cap on the pen; and, when the cap is removed from the pen and placed at a reference position, communicating wave energy between at least one location on the pen and at least one location on the cap for determining the position of the at least one location on the pen with respect to the reference position of the cap, and for producing signals that depend on the determined position of the at least one location on the pen.

Abstract: A method for wavelet encoding image-representative signals, including the following steps: identifying shape information of a shape in the image; within rows of pixels of a shape, performing wavelet decompositions for segments of consecutive pixels in the shape; for segments of pixels having out of the shape pixels in a wavelet decomposition, forming a zero tree that includes don't-care nodes and having uncoded don't-care descendents of don't-care nodes.

Abstract: Enclosed workplaces within a building are kept habitable by a central HVAC (heating, ventilating and air conditioning) system. These systems are designed and operated in accordance with professional standards-of-care promulgated by ASHRAE (American Society of Heating, Refrigeration and Air Conditioning Engineers), the ASHRAE 62-1989 Standard. An intent of the Standard is to preclude the recirculation of contaminants which, without mitigation, degrade indoor air quality. The disclosure is directed to an insertion module for installation in the return air path of an HVAC system that includes first and second stages that reduce nitrogen dioxide and ozone contaminants, in a gas-to-gas dry process reaction, to set point controlled levels in the return air.

Abstract: A method is disclosed for depositing diamond film on a plurality of substrates, which comprises the steps of: providing a plasma beam containing atomic hydrogen and a carbonaceous component; providing a plurality of substrates, each of the substrates having a deposited surface, the substrates being arranged such that the beam impinges successively on a deposition surface of a first substrate and then on a deposition surface of a second substrate, the deposition surfaces of the first and second substrates being oriented with respect to each other at a non-zero angle.

Abstract: A charged particle emitting assembly comprises an emitter member (5) for emitting charged particles of one polarity. A tubular shield electrode (6) circumferentially surrounds the emitter member and is held in use at the same polarity as the charged particles. A tubular accelerating electrode (7) is positioned substantially coaxially with the shield electrode (6) and is held in use at the opposite polarity to the shield electrode. The arrangement is such that charged particles from the emitter member (5) initially spread laterally outwardly and then are focused into a beam which passes through the tubular accelerating electrode (7).

Abstract: A method for decoding an encoded signal that includes an encoded control portion and an encoded video portion, includes the following steps: providing a plurality of inverse transform functions; decoding the encoded signal to recover the control portion; selecting one of the inverse transform functions in accordance with the recovered control portion; and decoding encoded video portion with the selected inverse transform function.

Abstract: A semiconductor light emitting device is disclosed. The device has a tunnel junction disposed between a p-type layer and an n-type layer. The tunnel junction includes a tunnel barrier that is a non-continuous layer. The device also includes means for causing lateral electron flow into the tunnel junction.