Abstract: Method and system for selectively adding and dropping selected wavelength components &lgr;=&lgr;k1 and &lgr;=&lgr;k2 (1≦k1≦k2≦K) in a light signal having a sequence of wavelengths &lgr;k (k=1, 2, . . . , K), using a dual fiber collimator at each end of an OADM device that contains an optical filter that transmits a selected wavelength &lgr;k1 and reflects the other wavelengths &lgr;k. Connecting two optical communication terminals in a network allows addition and dropping of a selected wavelength. Estimated total optical insertion losses, between the common port and the express port, for 2×2 and 3×3 add/drop combinations are 0.4 dB and 0.8 dB, respectively.

Abstract: Exercise/therapy apparatus that allows a user to change one or more workout parameters without dismounting from the apparatus and without interrupting the workout. Several embodiments for inclined surface apparatus are disclosed, using vertical, tiltable and curvilinear surface support structures.

Abstract: Method and system for providing laser light that is tunable over a relatively wide mid-infrared wavelength range, such as 2-17 &mgr;m. A first noncritically phase matched nonlinear crystal receives a laser light beam and converts the light to a first cavity beam having a first selected wavelength, using optical parametric oscillation techniques. A second noncritically phase matched nonlinear crystal receives the first cavity beam and converts the light to a second cavity beam having a second selected wavelength. Where the first wavelength is tuned (e.g., by temperature change or effective path length change) over a wavelength range of 2-5 &mgr;m, the second wavelength can vary over a higher and broader wavelength range, such as 3-17 &mgr;m.

Abstract: Method and system for converting a first light beam having a first frequency into a second light beam having a second frequency. A pump photon having (angular) frequency 3&ohgr; (or 4&ohgr;) is provided within an optical cavity, defined by two mirrors that are fully reflecting at a frequency 2&ohgr;. In a first approach, the pump photon is received and down-converted (3&ohgr;→2&ohgr;+&ohgr;) by a first nonlinear crystal, and the 2&ohgr; photon is further down-converted (2&ohgr;→&ohgr;+&ohgr;) by a second nonlinear crystal), to produce three photons (&ohgr;+&ohgr;+&ohgr;) that exit from the cavity. In a second approach, the pump photon is received and down-converted (4&ohgr;→2&ohgr;+2&ohgr;) by a first nonlinear crystal, and one or both of the 2&ohgr; photons is further down-converted (2&ohgr;→&ohgr;+&ohgr;) by a second nonlinear crystal).

Abstract: A phrase discovery is a method of identifying sequences of terms in a database. First, a selection of one or more relevant sequences of terms, such as relevant text, is provided. Next, several shorter sequences of terms, such as phrases, are extracted from the provided relevant sequences of terms. The extracted sequences of terms are then reduced through a culling process. A gathering process then emphasizes the more relevant of the extracted and culled sequences of terms and de-emphasizes the more generic of the extracted and culled sequences of terms. The gathering process can also include iteratively retrieving additional selections of relevant sequences (e.g., text), extracting and culling additional sequences of terms (e.g., phrases), emphasizing and de-emphasizing extracted and culled sequences of terms and accumulating all gathered sequences of terms. The resulting gathered sequences of terms are then output.

Abstract: System and method for simultaneously providing a wavelength spectral distribution and a temporal distribution of an incident light beam. The light beam is received at a wavelength spectral distribution module and is separated into light beam segments corresponding to at least two different wavelengths in a first selected direction transverse to beam propagation direction. The light beam is also received at a temporal distribution module, and segments of the light beam are distributed corresponding to at least two different times at which light in the beam was produced, in a second selected direction that is substantially perpendicular to the first direction. The temporal distribution module may include a rotating segmented mirror.

Abstract: A versatile serial to parallel interface capable of both receiving multiple types of input formats and operating in multiple operational modes includes a multiplexer, a signal generator, and a register. The multiplexer receives serial data from a plurality of possible data sources and, in response to a set of selection signals, outputs one of the sets of serial data to the signal generator. The signal generator thereafter forwards the serial data to the register for storage. In addition to forwarding the serial data to the register, the signal generator also generates clock and control signals. These signals are used to control the operation of the register to ensure proper serial to parallel conversion of the input serial data. In addition, these signals may also be provided to the source of the serial data to control the actions of the data source. The signal generator generates the clock and control signals in response to indication information provided to the signal generator.

Abstract: A data sampling system, including a data tracking circuit and a data latching circuit, that reduces the likelihood of metastability that arises through competition of the two circuits, where data sampling occurs in a transition time interval. A combined latching and weakened tracking circuit is provided in which the tracking operation cannot change an output signal from the latching operation after the latch resolves a valid logical state.

Abstract: Method and system for efficiently and quickly forming a sequence of convolution values from an over-sampled digital signal sequence. Convolution value differences are computable from a set of digital signal values that is smaller than the original set of signal values by a factor of R, the over-sampling rate. The number of adders and the associated time delay for computation of the convolution differences are reduced by at least a factor R and by at least a factor approximately proportional to log2(R), respectively, as compared to conventional computation of a convolution value. This approach is used to estimate a time value for which the convolution attains a largest magnitude or value.

Abstract: On data writes to a cache memory in a digital data processing system, the existing data currently stored on the desired cache storage line is read out and parity checked. The read-out data is modified with new data only if there is no parity error. If a parity error is detected, a cache miss is signaled and the read-out line of data is written back into the cache memory with error correction code checking and error correction being performed on the defective line of data as part of this write-back to the cache memory.

Abstract: System and method for improved formation of a Q-parity checkbyte matrix used for error control for a sequence of message bytes and error control bytes, using an algorithm, rather than a lookup table, to determine the order of the words used for the sequence. Entries of a Reed-Solomon parity check rectangular array are set up sequentially and diagonally, including the syndrome bytes and checkbytes to be used for error detection, so that all matrix entries can be written to, or read from, a computer memory in a stream of bytes whose order is determined by the algorithm without reference to a lookup table.

Abstract: System and method for wavelength discrimination using a DWDM (N+1)-stage fiber optic cascade tree structure with additional filtering to provide acceptable flat-top passband response, and to provide acceptable optical isolation when combined with a multilayer thin film filter. Each channel in a DWDM cascade tree structure has a conventional Mach-Zehnder interferometer (MZI) that provides wavelength discrimination. Each channel in at least one stage has an additional filter that is either (1) an inverted Fabry-Perot etalon (FPE) or (2) an inverted, non-symmetric MZI. The number of output channels may be 32, 64, 128 or more.

Abstract: Method and system for estimating a concentration of free electrons with a selected spin polarization in a semiconductor material. A static magnetic field and an electromagnetic field are impressed on the semiconductor, and free electrons are injected (through diffusion or tunneling) into the semiconductor material from a ferromagnetic material. Motion of the injected, spin-polarized electrons, within the semiconductor gives rise to a Hall voltage across the semiconductor. This voltage is measured at one or more spaced apart locations and analyzed to detect presence of, and estimate a concentration of, free electrons with a selected spin at at least one location within the semiconductor. Effects of an imposed stress, temperature, illumination or electromagnetic field on the semiconductor can be determined.

Abstract: Method and system for accurate vehicle navigation and tracking within a selected lane on a roadway or a waterway. A location determination (LD) receiver, carried on the vehicle, receives LD signals from satellite-based LD signal sources, receives LD signal correction information from one or more other wide area LD correction sources, estimates a corrected vehicle location (good to within 10-50 cm) and velocity (optional) relative to one or more lane boundaries that define the selected lane, and displays vehicle location and velocity within the lane. When the vehicle approaches a lane boundary too quickly, or is too close to the lane boundary, an alarm signal or other control mechanism can be activated. The LD correction information is delivered to the LD receiver via a channel of suitable bandwidth. The system can also be used to map and store lane boundary coordinates for selected segments of a roadway or waterway.

Abstract: Method and system for generating a sequence of two or more light beam central frequencies. A first mirror, in an optical cavity defined by two or more mirrors, is moved to a sequence of two or more locations relative to a second mirror in the cavity. The first mirror location is dithered relative to the second mirror for each location in the sequence to produce a light beam having a dithered sequence of cavity frequencies that are related to longitudinal mode resonant frequencies for the cavity. Alternatively, frequency locking is implemented for each of the sequence of central frequencies. The light beam may be passed through a sample within the cavity for spectroscopic measurements or may be extracted from an empty cavity to provide a sequence of light beam frequencies for a subsequent application.

Abstract: The present invention simulates the behavior of a storage component by first determining whether a timing violation has occurred for the storage component. If one or more timing violations is detected, then an x (indicating uncertainty) is reflected at the output of the storage component. This x is maintained at the output of the storage component for a predetermined number of timing units. After the predetermined number of timing units has expired, the output of the storage component is changed from x to a certain value, such as a logical 1 or a logical 0. By changing the output to a certain value, the present invention prevents the x at the output of the storage component from indefinitely propagating to other components in the circuit. This in turn prevents large numbers of x's from appearing in the simulation results provided to the designer. Instead, values that are certain will appear in the results.

Abstract: A system for monitoring location and speed of a vehicle, using a location determination system such as GPS, GLONASS or LORAN and an optional odometer or speedometer, for determining and recording the locations and times at which vehicle speed is less than a threshold speed for at least a threshold time (called a “vehicle arrest event”). Vehicle arrest event locations, times and time intervals are stored and/or printed to provide trip and mileage records and for efficiency monitoring. A vehicle odometer and/or speedometer can also be calibrated and/or corrected using this approach.

Abstract: A buffer circuit and method provide substantially constant output signal edges to facilitate service as a bus driver with enhanced timing flexibility. The buffer circuit includes a NOR gate and a NAND gate for driving output pulldown and pullup transistors. The initiation of current flows through the NOR and NAND gates is controlled by an environmentally adaptive reference circuit. First and second transistors are provided respectively between the NAND gate and the pullup transistor, and between the NOR gate and the pulldown transistor, to produce enhanced sourcing and sinking currents. The enhanced sinking and sourcing currents are timely terminated by switching of the pulldown and pullup transistors to save energy.

Abstract: MOS Cascode amplifier circuits are subject to long-term or instantaneous changes (degradation) of performance characteristics by excess substrate currents. These currents can be generated in the grounded source transistor of the cascode connected output transistors during peak excursions of drain-source voltage across the grounded source transistor when the output voltage of the MOS Cascode amplifier circuit is at a maximum. An improved MOS Cascode amplifier circuit arrangement includes a voltage limiting bias circuit arrangement of additional transistors. The bias circuit arrangement acts as a series voltage-limiting device between the MOS Cascode amplifier circuit output node and the drain node of the upper-most cascode connected transistors when the MOS Cascode amplifier circuit output voltage is at its maximum value.