Abstract: The present invention provides a word voter for redundant systems with n modules wherein each of these n modules generates a word output. The word voter receives word outputs from each of the n modules. A voter decision is generated by the word voter utilizing a word basis of the word output of each of the n modules. The voter is based on a majority voting principle. The advantage of the present invention is that the word voter can be used to design redundant systems, such as, but not limited to, TMR systems, that are protected against common mode and multiple output failures. In addition, another advantage of the present invention is that is provides for a technique to efficiently design a TMR simplex system. The present invention provides a word voter for hardware systems.

Abstract: A planar 2×2 switch is provided for controllably coupling first and second input channels to first and second output channels. The switch includes a first reflector that is movable between a first position and a second position. When the first reflector is in its second position, it reflects light from the first input channel to the second output channel and reflects light from the second input channel to the first output channel. When the first reflection is in its first position, it does not affect the optical beams in the switch. Instead, these beams are reflected by a second reflector which has two reflective surfaces. The second reflector reflects light from the first input channel to the first output channel and reflects light from the second input channel to the second output channel. Switches having a larger number of input and output channels are also provided.

Abstract: A fiber amplifier in a depressed cladding or W-profile fiber. The fiber has a core doped with the active material and defined by a core cross-section and a refractive index no. A depressed cladding of index n1 surrounds the core and a secondary cladding of index n2 surrounds the depressed cladding. The fiber amplifier is pumped to a level of high relative inversion, such that the active material exhibits positive gains in a short wavelength band and high gains in a long wavelength band. The core cross-section, the depressed cladding cross-section and the refractive indices no, n1, and n2 are selected to obtain a roll-off loss curve about a cutoff wavelength ?c. The roll-off loss curve yields losses at least comparable to the high gains in the long wavelength band and losses substantially smaller than the positive gains in the short wavelength band.

Abstract: An optical communication system such as a Wavelength-Division-Multiplexed (WDM) or Dense Wavelength-Division-Multiplexed (DWDM) communication system using Erbium doped fiber amplifiers (EDFAs) for amplifying signals in the S-band. The fiber amplifier has a core doped with Erbium and defined by a core cross-section and a refractive index n0. The fiber amplifier has a depressed cladding surrounding the core and a secondary cladding surrounding the depressed cladding. The depressed cladding has a depressed cladding cross-section and a refractive index n1, and the secondary cladding has a secondary cladding cross-section and a refractive index n2. The fiber amplifier has a pump source for pumping the Erbium to a level of high relative inversion D such that the Erbium exhibits positive gains in the S-band and high gains in a long wavelength band longer than the S-band, i.e., in the C- and L-Bands.

Abstract: The invention provides a plug-and-work sensor interface device named “puck” for fast and easy deployment of various types of serial devices, which include commercial off-the-shelf and custom-made sensors and instruments, in a distributed, dynamic oceanic observing network. In an embodiment, each puck is removably attached and electrically coupled to a specific sensor to be deployed. The puck comprises a non-volatile memory for associating and storing arbitrary binary information about the sensor and a microprocessor for controlling how the information is read from and written into the non-volatile memory. The sensor information may include unique sensor identifier, sensor metadata, sensor device driver, etc. The puck itself does not execute any of the device code; rather, a host retrieves the sensor information from the puck when the puck is plugged in. The retrieval can be done automatically or semi-automatically with user interaction.

Abstract: An optical circulator has a first collimator; a first block of birefringent material; a first compound polarization rotator; a light angle deflector (e.g., Wollaston prism); a second compound polarization rotator; a second block of birefringent material; and a second collimator. Light from the first fiber exits the first collimator along a first path into a first collimated beam that first hits the central plane on a crossing line between the interface and the central plane such that the first collimated beam exits the light angle deflector along a second path substantially parallel to the longitudinal direction and is received by the second fiber. Light from the second fiber exits the second collimator along the second path into a second collimated beam that exits the light angle deflector along a third path and is received by the third fiber.

Abstract: A resource allocation method for use in a wireless ATM network comprises receiving on a wireless signaling channel a request for access to a shared frequency-time sliced wireless medium. A channel matrix is then searched for a set of available frequency-time slots. The channel matrix represents a time frame within the shared frequency-time sliced wireless medium, and is used to keep track of resource allocation in the time-frequency sliced medium. The set of available time-slots is then allocated if the allocation does not violate a frequency switching constraint, and if the set of available frequency-time slots contains a number of slots no smaller than a requested number of slots. In a preferred embodiment of the invention, the searching step uses a greedy resource allocation strategy to search a channel-chunk matrix comprising a list of contiguous chunks of available time slots in each frequency of the shared frequency-time sliced wireless medium.

Abstract: A method is provided for determining the positional accuracy of leaves of a multileaf collimator for delivering doses of radiation to a particular spatial location for treatment purpose. The method could be implemented as routine quality assurance check of the multileaf collimator leaf positioning errors. The method includes producing a first field and producing a second field, which is different from the first field. A dosimeter means is included for measuring a radiation dose difference or ratio between the first field and the second field at at least one spatial location. The dose difference or ratio is then used to determine the positional accuracy of the leaves by comparing with a known relationship between leaf positional errors and relative dosimeter outputs. The method provides a more simplified, accurate, efficient and reliable method over currently used methods.

Abstract: An apparatus and method for determining a physical parameter of features on a substrate by illuminating the substrate with an incident light covering an incident wavelength range ??, e.g., from 190 nm to 1000 nm, where the substrate is at least semi-transparent. A response light received from the substrate and the feature is measured to obtain a response spectrum of the response light. Further, a complex-valued response due to the feature and the substrate is computed and both the response spectrum and the complex-valued response are used in determining the physical parameter. The response light is reflected light, transmitted light or a combination of the two. The complex-valued response typically includes a complex reflectance amplitude, a complex transmittance amplitude or both. The apparatus and method take into account the effects of vertical and lateral coherence length and are well suited for examining adjacent features.

Abstract: A magnetoresistive (MR) sensor can be shaped using ion beam irradiation and/or implantation through a mask introduced between a MR structure and an ion source. The mask covers selected portions of the MR structure to define the track width of the sensor. Ion irradiation and/or implantation reduces the magnetoresistance of the unmasked portions while leaving the masked portion substantially unaltered. The mask can be a photoresist mask, an electron beam resist mask, or a stencil mask. Alternatively the mask may be part of a projection ion beam system. Track width resolution is determined at the mask production step. The edges of the sensor can be defined by a highly collimated ion beam producing an extremely straight transition edge, which reduces sensor noise and improves sensor track width control. Improved hard bias layers that directly abut the sensor may be used to achieve a suitable stability. A variety of longitudinal bias schemes are compatible with ion beam patterning.

Abstract: A method for embedding fiber optic sensors in a high melting temperature metal structure produces embedded sensors that are uniformly and closely bonded with the metal and do not slip upon metal expansion and contraction. The structure is built in layers onto the sensor. On top of a first thin sputter-coated metallic layer, approximately 1-3 ?m thick, is electroplated a second thin layer, approximately 0.25-2 mm thick. Finally, a metal structure is built around the thin metallic layers by laser cladding, casting, welding, or other method.

Abstract: A Thulium-doped silica fiber normally has its strongest gain at 1.9 microns and thus is not suitable for communication use. By engineering a W-profile or depressed cladding fiber with an appropriate index profile having a fundamental mode cut-off between 1.9 microns and the shorter wavelength of desired operation, an optical amplifier based on the W-profile Thulium-doped silica fiber operates at wavelengths shorter than conventional amplifiers, just above what is currently called the Erbium L-band. In a preferred embodiment, the cut-off wavelength is at or near 1.7 ?m, eliminating longer wavelengths from the fiber. Amplifiers engineered according to the principles and techniques of the present invention can operate in the wavelength range between about 1.6 to 1.8 microns, which is particularly useful for telecommunications.

Abstract: A flywheel for use as an energy storage device is made of hoops of different fiber composite layers, the radial thickness of each hoop and the physical properties of the fiber composite in each loop being chosen by a computer modeling optimization procedure to maximize total energy of storage while minimizing radial stress.

Abstract: In a spin valve, an underlayer is made of oxygen-rich nickel oxide to enhance the giant magnetoresistive ratio (?R/R). The oxygen-rich nickel oxide film is made using reactive sputtering of a nickel target in an oxygen-rich sputtering atmosphere consisting substantially of pure oxygen and argon gases. The total pressure of the oxygen-rich atmosphere is reduced during the oxygen-rich nickel oxide film formation to additionally enhance the ?R/R value. A spin valve including two adjacent oxygen-rich nickel oxide underlayers provides a higher ?R/R ratio at a given pinning strength Hua than does a spin valve having only one oxygen-rich nickel oxide underlayer.

Abstract: A multipath mitigation method consists of locating a multipath-invariant (MPI) point of an ideal autocorrelation function and measuring the distance between the MPI point and DLL. The same MPI point is located in a received correlation function, and the distance between the point and the DLL, now affected by multipath, is measured. The difference between the ideal distance and the actual distance is the code tracking error resulting from multipath. The error is subtracted from the computed pseudorange or used to control the DLL. The method can be used to reduce the effects of all types of tracking error sources, such as signal transmission failure or code noise.

Abstract: A method of generating intender leads in a distributed computer system includes the steps of identifying purchase indicators and extracting prospect identifiers from the purchase indicators. Purchase indicators are pieces of data that represent a potential future purchase by a prospect. For example, an online classified advertisement selling an automobile is a purchase indicator for a potential future purchase of a new car by the old car seller. The prospect identifier, such as a telephone number or email address, uniquely identifies the prospect likely to make the future purchase. Preferably, the method also contains the steps of obtaining full contact information for the prospect from a profile database, applying a predictive model to the prospects to select intender leads, and transferring the intender leads to an interested party, such as a direct marketing service or sales force.

Abstract: The present invention provides a miniature gas turbine engine for power generation. The engine has a highly integrated unitary rotor shaft where turbine, compressor and shaft are made in one piece in one fabrication process. The turbine and compressor are positioned back to back on the shaft in an overhung configuration, allowing the front bearings to be located in the cold zone of the engine. Preferably, the Mold SDM fabrication technique is utilized to make the unitary rotor shaft in one monolithic part out of ceramics such as silicon nitride, eliminating the need for post process assembly while strengthening the integrity, reliability, and performance of the unitary rotor shaft. Integrated with a permanent magnet in the unitary rotor shaft, the miniature gas turbine engine can generate electric power of 1 kW or less. Additionally, the axial length of the miniature gas turbine engine is about 100 mm or less.

Abstract: The invention provides microfabricated silicon substrates and devices having extremely small apertures (termed “nanoapertures”) and methods for producing such nanoapertures. The devices have a nanoaperture (which may have a diameter ranging from about a few millimeters to as small as a few nm) across a substrate effective to connect two regions separated by the substrate. The devices are suitable for the formation of lipid bilayer membranes across the apertures, and for use in devices such as biosensors. Substrates and devices may include multiple nanoapertures, which may each support a lipid bilayer membrane, allowing fault tolerant devices such as fault-tolerant biosensors, and allowing devices able to sense more than one target molecule.

Abstract: A water-cooled auxiliary condenser device 200 receives refrigerant from an external refrigeration system 210 just downstream from its air-cooled condenser 110. The refrigerant passes through a water-cooled condenser 250, and the refrigerant state is sensed by a temperature or pressure sensor 226. If the sensed state of the refrigerant rises above a first threshold, the flow of water through the water-cooled condenser 250 is increased, e.g., turned ON, using a controllable water valve 234. When the sensed state of the refrigerant drops below a second threshold, the water flow through the water-cooled condenser 250 is decreased, e.g., turned OFF. The refrigerant returns to the refrigeration system just upstream from its liquid receiver 120. In the event that air-cooled condenser 110 fails, device 200 automatically activates the water-cooled condenser 250 to maintain safe refrigeration temperatures in the appliance. When not required, device 200 remains passive and does not use any water or electric.

Abstract: The present invention provides an apparatus for determining a wavelength of an optical signal by determining a coarse wavelength response and a fine wavelength response. The coarse wavelength response is achieved by utilizing an optical filter. A suitable detector detects the wavelength-dependent response and conveys the determined coarse wavelength response to the processing logic. The fine wavelength response is achieved by utilizing an interferometer that is capable of generating an interference pattern. Two detectors are disposed in the interference pattern at a quadrature separation from each other and detect the intensity responses at their respective locations. The intensity responses are conveyed to a unit that determines the fine wavelength response. Finally, the processing logic determines the wavelength utilizing the determined coarse wavelength response and the determined fine wavelength response.