Abstract: The present invention is directed to predicting and optimizing the exposure value of cameras in order to properly capture images, achieve robust and efficient calibration, and detect faults. The present invention features a method comprising displaying one or more reference images and using the camera to capture the reference image at one or more camera exposures. This allows an optimal camera exposure and an optimal reference image to be determined. The method may further comprise estimating ambient light. The method may further comprise the display device displaying an input image and identifying relative properties of the input image in comparison to the reference image. The method may further comprise predicting an optimal exposure based on the relative properties of the input image, ambient light, and the optimal reference exposure, adjusting the exposure value of the camera based on the optimal exposure, and capturing the input image at the proper exposure.

Abstract: A method for using citraconic anhydride and itaconic anhydride as addition cure end caps in reactions for forming polyamic acid oligomers and polyimide oligomers, is provided. Prepregs and high temperature adhesives made from the resulting oligomers, as well as, high temperature, low void volume composites made from the prepregs, are also provided.

Abstract: A device may be capable of communicating using at least two type types of modulation methods. Methods and systems are provided for communication of data according to a communications method in which a master transceiver communicates with one or more slave transceivers according to a master/slave relationship. A first data message may include first information and second information that are modulated according to a first modulation method. The second information may include lower data rate data. A second data message may include third information that may be modulated according to the first modulation method and that may indicate an impending change to a second modulation method. The second modulation method may be used for transmitting fourth information, and the fourth information may be included in the second message. The fourth information may include higher data rate data, for example Internet access data.

Abstract: A device may be capable of communicating using at least two type types of modulation methods. The device may include a transceiver capable of acting as a master according to a master/slave relationship in which communication from a slave to a master occurs in response to communication from the master to the slave. The master transceiver may send transmissions structured with a first portion and a payload portion. Information in the first portion may be modulated according to a first modulation method and indicate an impending change to a second modulation method, which is used for transmitting the payload portion. The discrete transmissions may be addressed for an intended destination of the payload portion.

Abstract: The present invention is directed to unique methods and apparatus for suppressing impulse noise in a multipoint communications environment using a linear block interleaver. One representative embodiment comprises first logic configured to arithmetically combine a time series of input symbols into a block of N-symbol combinations, and second logic configured to transmit, on a separate channel, each N-symbol combination to a receiver. The first logic is located in a transmitter of a first communications device. The time series has size N and N is greater than one, and each of the input symbols is taken from a signaling constellation.

Abstract: The present invention provides for a system and method for reducing power consumption in frame and cell data transmission systems. A transmitter power manager powers down (turns off) selected elements of a transmitter system during periods of transmitter inactivity. The transmitter power manager system detects incoming communication signals which are to be transmitted by the transmitter, and at the appropriate time, powers up (turns on) the selected elements which are controlled by the transmitter power manager.

Abstract: A system and method for providing a minimum burst duration in accordance with a regional standard and/or requirement. One embodiment comprises a first interface (204) configured to receive data to be communicated, a memory (208) configured to store a value corresponding to a regional minimum duration, a processor (202) configured to generate a frame, configured to compare a duration of the generated frame with the regional minimum duration, configured to add at least one padding symbol to the generated frame to generate a second frame, the second frame having a duration at least equal to the regional minimum duration, and a second interface (206) configured to communicate the second frame onto a communication channel.

Abstract: A single subscriber line multi-point communication system is disclosed. In general, the multi-point communication system can include a first transceiver coupled to a subscriber line capable of transmitting and receiving at least two modulation methods, either of said modulation methods being operable to transmit a test signal, and a second transceiver coupled to said subscriber line capable of transmitting and receiving said at least two modulation methods, the second transceiver being operable to receive the test signal and determine at least one channel parameter from the test signal. A master transceiver that can be used in various embodiments of a single subscriber line multi-point communication system, and a tributary transceiver are further disclosed.

Abstract: A symbol timing derivation system derives receiver timing from received symbols which avoids the need for a pilot tone, thereby reducing power consumption and expanding usable bandwidth. The system is implemented by using a calculation that finds the timing phase error. The timing phase error is then averaged and controls a phase locked loop (PLL). This PLL in turn controls a voltage-controlled oscillator, which handles the modem receiver timing. A centroid calculation can be included to bias the voltage-controlled oscillator to push the equalizer coefficients back to the ideal position. The system can be implemented in either a point-to-point modem environment or a multi-point environment, for example, but not limited to, MVL or DMT. The voltage-controlled oscillator may also be implemented to control transmitter timing, so that the central office modem and the remote modem will operate more-or-less synchronously, reducing the need for large equalizer corrections at either end.

Abstract: Indirect digital subscriber line (DSL) service generally involves connecting conversion equipment that converts between DSL service delivered to a customer premises and DSL service that connects back to a data network. Indirect DSL service may be delivered on the same loop to the customer premises that also carries a native 0-4 KHz POTS interface. For larger deployments, the conversion equipment may include inverse multiplexing to combine multiple links back to the data network to support DSL service. Furthermore, the conversion equipment may include functions to digitize the POTS service. Aggregating DSL data from multiple customers and/or digitizing POTS service that may be multiplexed with the DSL data allows for significant pair gain opportunities.

Abstract: The preferred embodiments of the present invention generally provide improved communications over a subscriber loop that is loaded with at least one and potentially a plurality of load coils. The preferred embodiments of the present invention will work over loaded subscriber loops that also support a native POTS interface as well as over loaded subscriber loops that are not providing a native POTS interface. Furthermore, although the preferred embodiments of the present invention are intended to address the technical and business problems of service providers delivering digital subscriber line service over loaded loops, the preferred embodiments will also work over unloaded loops.

Abstract: The invention features improvements in PRK procedures that relate to preventing non-uniform removal of material from the corneal surface. It has been realized that photoablation by-products resulting during the PRK procedure can affect the accuracy and the predictability of the procedure. Under certain conditions, the plume of photoablation by-products that have left the corneal surface can non-uniformly redeposit onto the ablation area and thus affect the uniformity of subsequent material removal. The plume of photoablation by-products, in the space above the corneal surface, can also non-uniformly affect the escape of further photoablation products from the surface. In addition to the plume effects, it has been realized that the hydration level of the corneal tissue during the PRK procedure can vary over the ablation area and likewise non-uniformly affect the PRK procedure.

Abstract: Methods and apparatus are disclosed for removal of biological tissue slices or layers, preferably in the form of lamellar sections of predetermined shape and thickness employing a reference member that engages a target tissue site and cooperates with a cutter in order to remove the tissue segment or lamella. The cutter can include a flexible cutting element such as a wire or band element that is brought into physical contact with a guiding edge integrated with, or otherwise coupled to, the reference member. Alternatively, the cutter can include a stiff rigid blade element that is maintained in contact with the guiding edge. The cutter is drawn along a path defined by the guide edge through the tissue to sever, at least partially, a tissue section. In one particularly useful aspect of the invention, devices for keratectomy are disclosed employing an ocular reference member that engages the upper central region of the cornea and cooperates with a cutter to remove a lamellar segment from the cornea.

Abstract: Methods and apparatus for corneal reprofiling are disclosed in which a beam-swapping assembly is employed to redirect rays of ablative radiation passing through the assembly. Essentially, the beam-swapping assembly turns the beam profile "inside out" redirecting the inner most rays to the periphery of the beam while redirecting the outer rays at the same time to the center of the beam. The beam-swapping assembly can be used in conjunction with a beam-shaper, such as an adjustable iris or other beam-shaping device, to create convoluted annular ablation patterns of variable depth and, thereby, perform hyperopia and/or astigmatism correcting procedures.

Abstract: A beam profiler comprising: an intensity modifier constructed and arranged to separately modify the intensity profile of different subbeam portions of an initial beam to thereby create respective subbeams each having a respective predetermined modification; and a subbeam-directing optical system constructed and arranged to direct the multiple subbeams along respective subbeam beam paths that substantially overlap in an overlap plane, whereby, a resulting beam of radiation is created at the overlap plane that has an intensity profile equal to the optical incoherent summation of the predetermined intensity profiles of said overlapping subbeams. The intensity modifier preferably comprises an array of intensity-modifying profiling elements disposed across the initial beam each producing a corresponding subbeam.

Abstract: Methods and apparatus are disclosed for removal of biological tissue slices or layers, preferably in the form of lamellar sections of predetermined shape and thickness employing a reference member that engages a target tissue site and cooperates with a cutter in order to remove the tissue segment or lamella. The cutter preferably includes a flexible cutting element such as a wire or band element that is brought into physical contact with a guiding edge of the reference member and then draw along a path defined by the guide edge through the tissue to sever, at least partially, a tissue section. In one particularly useful aspect of the invention, methods and apparatus for keratectomy are disclosed employing an ocular reference member that engages the upper central region of the cornea and cooperates with a cutter to remove a lamellar segment from the cornea.

Abstract: A method and system are described for performing photorefractive keratectomy procedure employing pulses of photoablative radiation to selectively ablate corneal tissue of a patient's eye in an ablation zone on the anterior corneal surface to produce a desired refractive correction in the corneal tissue. The method and system employ control of the effect of ocular fluid at the corneal surface so as to reduce the disturbance of such fluid on the desired ablation process while maintaining hydration of the corneal tissue.

Abstract: A calibration apparatus is disclosed for measuring the properties of a laser beam. The apparatus includes a photoreactive element having a composition which reacts with laser radiation in a manner proportional to the intensity or intensity profile of the laser beam and an alignment means for disposing the photoreactive element in the path of a laser beam, such that the beam can be activate to impinge upon the photoreactive element and the properties of the beam are recorded by changes in the state of the calibration element. The calibration element may also be used to provide corrective feedback for modifying or controlling the properties of the laser beam.

Abstract: Apparatus and methods to modify the intensity distribution of a beam of radiation, such as a laser, and for eroding surfaces with predetermined shapes. A rotatable mask is formed with one or more apertures that have a geometric spiral shape originating substantially the center of rotation on the mask. The mask is insert to the beam for modification of the intensity of that beam, and additionally to form the desired etch pattern on a target surface. In a preferred embodiment, the invention is useful for performing kerotoplasty or keratomileusis.

Abstract: Methods and systems are disclosed for corneal reprofiling employing an annular beam of ablative radiation to correct refractive errors in vision, and/or create "blend zones" in order to reduce any surface discontinuities on the cornea following hyperopia-correcting or astigmatism-correcting procedures. Preferably, the methods and systems of the present invention also operate to change the intensity distribution of the light beam, such that the annulus of radiation has a varying intensity as a function of radius and, thereby, achieves a blending or other desired effect with the least number of pulses.