Abstract: Message cells that are allocated to virtual connections having different priorities are transmitted jointly over at least one transmission line of an ATM system working according to an asynchronous transfer mode. While being transmitted via the respective transmission lines, these message cells pass through a buffer memory individually allocated thereto. Given a buffer memory exhibiting a specific filling degree, one or more message cells from message cells of a selected virtual connection of low priority, which are, stored at the moment in the buffer memory, are discarded with the arrival of a message cell on the respective transmission line belonging to a virtual connection of relatively high priority, and dependent on the number of message cells stored for this virtual connection having low priority.

Abstract: A radio base station, when detecting a collision of reception signals, transmits an access-restricted transmission allow signal IDLE2 to a irrelevant-to-collision radio terminal PS3 for access restriction. A plurality of relevant-to-collision radio terminals PS1 and PS2, when receiving the access-restricted transmission allow signal, set transmission delay times TR1 and TR2 determined by random numbers, respectively, and when receiving the access-restricted transmission allow signal after the lapse of their respective delay times, start the same transmission operation as when receiving a normal transmission allow signal. A separate radio terminal PS3, when receiving the access-restricted transmission allow signal before intended new signal transmission, suspends the new signal transmission until receiving the normal transmission allow signal.

Abstract: A system and method for selecting one port among multiple output ports having various transmission rates attached to an output adapter of a switching node in a data transmission network and enabling it to transmit its data over the network. The system of the present invention includes a storage device that contains a list of identification codes for the ports. The identification code list is arranged in a prioritized order from the port having the highest transmission rate to the port having the lowest transmission rate. The system further includes port service request means that generate a service request signal for each port, wherein the service request signal has a frequency corresponding to the transmission rate of the object port.

Abstract: A generic backhaul protocol is provided for passing telecommunication signaling messages according to multiple signaling protocols between a gateway and a media gateway controller. A message in accordance with the generic backhaul protocol includes a message header that indicates the signaling protocol and/or the channel being used on the gateway. The message also includes a message body that contains a protocol data unit encapsulating signaling data in accordance with a signaling protocol.

Abstract: A signaling network layer protocol of an ATM-based mobile communication network including an MSC and an RNC connected by point-to-point in which a predetermined message form, a primitive between an upper and a lower layers, a state of a protocol individual and an operational procedure are defined so that a signal message between the MSC and the RNC is processed through a single signaling network layer (SNL).

Abstract: A method of reducing error-multiplication due to error events in a cell stream transmitted as a plurality of cell sub-streams which includes the steps of receiving an incoming cell stream in the form of an ordered sequence of cells including payload cells, transmitting the incoming cell stream in a round robin fashion on a plurality of physical links such that the ordered sequence of cells is transmitted as a plurality of cell sub-streams, with each cell sub-stream having a multiplexed set of cells from the incoming cell stream, and inserting stuff (st) cells into the cell sub-streams so as to form continuous streams of data. Sequence number cells which are inserted periodically into each cell sub-stream, are used to align the cell sub-streams in frames. Sets of cell location information for the cell sub-streams are encoded and contain the location of payload cells and st cells located within a corresponding cell sub-stream.

Abstract: A timer based header compression/decompression technique and timer and reference based technique are provided. A source generates a header field, such as an RTP time stamp. A packet including the header field is sent to a compressor which calculates a compressed header field based on the header field of the packet from the source and a jitter quantity. The compressed header field is calculated by calculating a jitter effect the network before the compressor has on the transmission of packets and calculating a jitter effect the network between the compressor and a decompressor has on the transmission of packets. The packet including the compressed header field is transmitted to a decompressor which includes a local timer. The decompressor decompresses the compressed header field by calculating an approximation of the header field based on the elapsed time since the arrival of a previous packet and the field value in the previous packet.

Abstract: Methods and devices are provided for converting a fundamental wavelength of a fundamental beam generated by a surface-emitting diode laser having a first resonating cavity. According to some embodiments, a first nonlinear crystal disposed in a second resonating cavity external to first resonating cavity converts the fundamental beam to a first output beam having a first output wavelength different from the fundamental wavelength. Some embodiments include a second nonlinear crystal, which may be disposed in the second resonating cavity or in a third resonating cavity, for producing a second output beam having a second output wavelength different from the first output wavelength. In some such embodiments, the second nonlinear crystal converts the wavelength of the first output beam to produce the second output beam. In some embodiments, the second nonlinear crystal interacts with the first output beam and an infrared beam from another laser device to produce the second output beam.

Abstract: A semiconductor laser 101 comprises a sapphire substrate 1, an AlN buffer layer 2, Si-doped GaN n-layer 3, Si-doped Al0.1Ga0.9N n-cladding layer 4, Si-doped GaN n-guide layer 5, an active layer 6 having multiple quantum well (MQW) structure in which about 35 Å in thickness of GaN barrier layer 62 and about 35 Å in thickness of Ga0.95In0.05N well layer 61 are laminated alternately, Mg-doped GaN p-guide layer 7, Mg-doped Al0.1Ga0.9N p-cladding layer 8, and Mg-doped GaN p-contact layer 9 are formed successively thereon. A ridged hole injection part B which contacts to a ridged resonator part A is formed to have the same width as the width w of an Ni electrode 10. Holes transmitted from the Ni electrode 10 are injected to the active layer 6 with high current density, and electric current threshold for laser oscillation can be decreased. Electric current threshold can be improved more effectively by forming also the p-guide layer 7 to have the same width as the width w of the Ni electrode 10.

Abstract: A semiconductor laser capable of emitting a plurality of laser light having different oscillation wavelengths which is formed with dielectric films having little fluctuation in reflectance at ends of a plurality of active layers and a method of production of the same, said semiconductor laser having a plurality of active layers having different compositions on a substrate and emitting in parallel a plurality of laser light having different oscillation wavelengths, wherein a front dielectric film having a predetermined thickness by which a reflectance with respect to light of a predetermined wavelength of an arithmetical mean of oscillation wavelengths becomes the extremal value is formed on an end of the laser emission side, while rear dielectric films having higher reflectances compared with the front dielectric film and having predetermined thicknesses by which reflectances with respect to light having a predetermined wavelength become the extremal values are formed on the end of the rear side, and a method

Abstract: When a laminated semiconductor portion of nitride based compound semiconductor is formed so as to constitute a portion forming a light emitting layer forming portion on a sapphire substrate, the sapphire substrate has an off orientation angle having a tilt relative to an A axis or a M axis in such a way that 0.2°≦&thgr;={&thgr;a2+&thgr;m2}1/2≦0.3°, wherein 0°≦&thgr;a≦0.3°, 0°≦&thgr;m≦0.3°, when taking the angle tilted relative to the A axis as &thgr;a and to the M axis as &thgr;m, and the foregoing nitride based compound semiconductor layers are laminated onto the surface of the off-oriented C plane.

Abstract: A semiconductor device and method for providing a light source suitable for use as a pumping light source in a Raman amplification system are provided. The device upon which the method is based includes an active layer configured to radiate light; a light reflecting facet positioned on a first side of the active layer; a light emitting facet positioned on a second side of the active layer thereby forming a resonant cavity between the light reflecting facet and the light emitting facet; and a partial diffraction grating having a predetermined length and positioned on a light emission side of the resonator. The predetermined length of the partial diffraction grating is selected such that the semiconductor device emits a light beam having a plurality of longitudinal modes within a predetermined spectral width of an oscillation wavelength spectrum of the semiconductor device.

Abstract: A ring-type laser including a traveling wave cavity which incorporates at least first and second straight cavity sections and at least one curved cavity section. Corresponding first ends of the straight cavity sections are interconnected at a first light-emitting facet, and second ends of the straight sections are interconnected by the curved waveguide. Additional curved and straight sections can be linked to provide various ring configurations.

Abstract: A ring resonator coupled laser is described, which has a gain region for creating light radiation, ring resonators for providing a strong mode selection and Vernier effect for wide wavelength tunability, passive waveguides for coupling the light and a pair of reflective mirrors for forming a laser cavity. By combining the ring resonators with the reflective mirrors, a strongly frequency-dependent passive mirror with complex amplitude reflectivity is formed and this ring resonator coupled laser exhibits single longitudinal mode operation with a high side mode suppression ratio, narrow linewidth and reduced frequency chirp. By using two slightly different ring resonators, the wavelength tunability is greatly enhanced. Thus, electro-optic effect is preferred for high speed wavelength tuning in the ring resonator coupled laser.

Abstract: A current confinement element that can be used in constructing light-emitting devices. The current confinement element includes a top layer and an aperture-defining layer. The top layer includes a top semiconducting material of a first conductivity type that is transparent to light. The aperture-defining layer includes an aperture region and a confinement region. The aperture region includes an aperture semiconducting material of the first conductivity type that is transparent to light. The confinement region surrounds the aperture region and includes a material that has been doped to provide a high resistance to the flow of current. In one embodiment of the invention, the confinement region includes a semiconducting material of a second conductivity type.

Abstract: Systems and methods of passivating planar index-guided oxide vertical cavity surface emitting lasers (VCSELs) are described. These systems and methods address the unique susceptibility of these devices to damage that otherwise might be caused by moisture intrusion into the etch holes that are used to form the index-guiding confinement regions. In one aspect, a VCSEL includes a vertical stack structure having a substantially planar top surface. The vertical stack structure includes a top mirror, a bottom mirror, and a cavity region disposed between the top mirror and the bottom mirror and including an active light generation region. At least one of the top mirror and the bottom mirror has a layer with a peripheral region that is oxidized into an electrical insulator as a result of exposure to an oxidizing agent. The vertical stack structure defines two or more etched holes each extending from the substantially planar top surface to the oxidized peripheral region.

Abstract: A surface emitting laser that provides an improved temperature characteristic, an improved optical output, and easy forming process. An optical communication system using this surface emitting laser is also provided. A surface emitting laser comprising: a substrate; a vertical cavity of layers formed on said substrate for propagating and resonating light along an axis vertical to a surface of said substrate, said light emitted from an active layer by current injection; and a reflective film disposed concentrically with the vertical axis around the outer periphery of said vertical cavity for reflecting the light from said active layer in a horizontal direction parallel to the surface of said substrate, the light emitted from said active layer forming a laser beam due to resonation, which laser beam is then emitted in a vertical direction. An optical communication system using the surface emitting laser.

Abstract: The invention provides a spread-spectrum transmission system with multiple carrier modulation in which the signals for transmission over each of the subcarriers are filtered prior to being transmitted over the subcarrier, thereby making it possible on reception to synchronize the various subcarriers in time, and in which each subcarrier carries a plurality of chips that result from spreading a single symbol. With coherent modulation, the number of chips resulting from spreading a single symbol and transmitted over each subcarrier is selected so as to enable the various subcarriers to be put into phase alignment by recombining the chips coming from the same symbol on each subcarrier. With differential modulation, the transmission over each subcarrier of chips resulting from spreading a single symbol provides resistance to jamming by limiting recombination losses because of the differential modulation.

Abstract: A receiver for use in a wireless communication system, for example a mobile phone system, the receiver having a plurality of fingers which can each receive signals from a different propagation path and can estimate the channel coherence time for the propagation path used by signals received by the respective finger. The receiver also has filtering circuity the operation of which is altered in dependence on the estimated coherence time.

Abstract: Techniques for increased pilot detection accuracy are disclosed, which provide the benefits of increased acquisition speed, increased data rate, decreased power, and improved overall system capacity. In one aspect, pilot energy calculations corresponding to PN offsets surrounding the PN offset of a local pilot energy maximum are combined with that local pilot energy maximum resulting in a compensated, more accurate local pilot energy maximum. In another aspect, the combination of nearby energy calculations is combined with the local pilot energy maximum via a function with pre-calculated compensation factors. The pre-calculated compensation factors can be determined to minimize mean-squared error in the resultant compensated local pilot energy maximum. These factors can be calculated based on a matched filter. The techniques described herein apply equally to both access points and access terminals.

Abstract: A Doppler spread for a communications channel is measured by providing an estimate of the communications channel and generating an autocorrelation function for the estimate of the communications channel. One of a plurality of autocorrelation function hypotheses is selected to approximate the autocorrelation function for the estimate of the communications channel wherein each of the autocorrelation function hypotheses corresponds to a respective Doppler spread estimate hypothesis. One of the Doppler spread estimate hypotheses is selected corresponding to the selected autocorrelation function hypotheses as an estimate of the Doppler spread for the communications channel.

Abstract: Methods and systems for data rate detection for multi-speed embedded clock serial receivers are described. In one embodiment, a method of determining a data rate of a high speed serially transmitted data stream comprises statistically examining edge characteristics of the incoming data stream. Based on the edge characteristics, a signature is identified that is associated with the edge characteristics. Based on the identified signature, a data rate at which the data stream is being transmitted is determined. In one embodiment, a clock extraction/data recovery circuit is provided for recovering an embedded clock and data from a high speed serially transmitted data stream. The circuit comprises a phase comparator that is configured to receive a high speed serially transmitted data stream and output indicia whenever the data stream experiences a data transition. A voltage controlled oscillator (VCO) is connected with the phase comparator and provides a clock signal having clock edges.

Abstract: A passband equalizer that performs blind equalization upon a complex signal, e.g., a vestigial sideband (VSB) signal, without using a training sequence. The passband equalizer contains a decision directed equalizer (DFE) that operates upon separate in phase (I) and quadrature phase (Q) signals using a filter for the I signal and a filter for the Q signal without using filters for cross components of the I and Q signals. As such, the DFE contains approximately half of the multipliers and adders that are used in prior art DFEs.

Abstract: The present invention proposes a new method and apparatus for the enhancement of source coding systems. The invention employs bandwidth reduction 101 prior to or in the encoder 103, followed by spectral-band replication 105 at the decoder 107. This is accomplished by the use of new transposition methods, in combination with spectral envelope adjustments. Reduced bitrate at a given perceptual quality or an improved perceptual quality at a given bitrate is offered. The invention is preferably integrated in a hardware or software codec, but can also be implemented as a separate processor in combination with a codec. The invention offers substantial improvements practically independent of codec type and technological progress.

Abstract: A decoder system having a motion compensation system that scales the processing of B pictures in order to save computational resources. The motion compensation system has a first scaling system that includes comparing a motion vector magnitude of each macroblock in a B picture with a predetermined threshold. A system for performing a routine decoding operation for each macroblock in which the motion vector magnitude is greater than the predetermined threshold and a system for copying a corresponding macroblock from a previous picture for each macroblock in which the motion vector magnitude is less than or equal to the predetermined threshold. A second scaling system that includes calculating an average motion vector magnitude for a first B picture and replacing a next contiguous B picture with the first B picture if the average motion vector magnitude is less than or equal to a predetermined threshold.

Abstract: A technique for use in a block transform-based coding system of processing (e.g., encoding and/or decoding) one or more block transform coefficients associated with at least one block of visual data (e.g., an image and/or video sequence) comprises the following steps. First, one or more previously reconstructed block transform coefficients associated with the visual data are identified. Then, a context selection value is computed for use in processing a block transform coefficient associated with the at least one block, the context selection value being based on the one or more previously reconstructed block transform coefficients. The context selection value may be computed as a function of one or more values respectively associated with one or more previously reconstructed block transform coefficients in near proximity, with respect to a scanning order, to the block transform coefficient to be processed.

Abstract: A multi-scanner scans a signal according to several different patterns. A scanning pattern selector determines which scanning pattern produced the most efficient coding result, for example, for runlength coding, and outputs a coded signal, coded most efficiently, and a selection signal which identifies the scanning pattern found to be most efficient.

Abstract: For transmitting digital video information over a network such as the Internet, a hybrid coding scheme (FIGS. 9-18) with wavelet I frame coding and H.263 predictive coding produces a robust, low bit rate video coding scheme. A new packetization method analyzes macroblock level dependency structure (FIG. 19) and packetizes the bit stream so as to minimize dependencies between packets and thereby minimize packet loss damage.

Abstract: A system for providing a common transport signal comprising an analog information signal and a digital information signal including a transmitter and a receiver for the common transport signal is disclosed. The transmitter includes an analog information signal modulator, placing the analog information signal onto a first intermediate frequency, a digital information signal modulator, placing a digital information signal onto a second intermediate frequency, a first upconverter and amplifier for upconverting the analog information signal, and a second upconverter for upconverting a frequency translated digital information signal. The system includes a power combiner for adding the upconverted analog and digital information signal to form a common transport signal. The receiver includes a signal receptor and conditioner, a signal splitter and dual signal recovery chains; each chain including at least a downconverter, a bandpass filter and intermediate frequency amplifier, and a signal demodulator.

Abstract: A method and apparatus for providing a precoder filter having peak-to-average ratio (PAR) controller that also serves as a high-pass, low-pass, or band-pass filter. The described invention is includes a modulo device connected in series with the PAR controller and a precoder filter connected in a feedback arrangement. The input to the apparatus is a sequence of data symbols and the output is a spectrally shaped precoded signal having a controlled peak-to-average ratio.

Abstract: A transmission line is monitored while the communication is held in a steady state and moving a tone set if there are no tones securing a predetermined value of an S/N ratio. The tone set is not moving if there are at least two tones securing the S/N ratio. The tone set is moved by the predetermined method if there is one tone securing the S/N ratio and it is judged that communication quality can be maintained by moving the tone set in a same tone group. The tone group moved if it is judged that the communication quality cannot be maintained even by executing movement of the tone set in the same tone group.

Abstract: A Viterbi trellis is provided which allows for implementation of either an EPRML type channel or an E2PRML type channel using a single trellis structure. According to a specific embodiment, a trellis is provided which can support a 0 mod 2 EPRML (M2EPRML) channel and a modified E2PRML (ME2PRML) channel.

Abstract: The invention provides a &pgr;/4 shift QPSK modulator, as well as a communication device, which is capable of reducing the storage capacity of ROM for previously storing impulse response data, and which allows the power consumption to be lowered and the circuit scale to be downsized. In an impulse response storage section within an impulse response computing circuit, storage capacity for impulse response data is halved by using, in common, impulse response data of a one-side waveform of an impulse response waveform bilaterally symmetrical with respect to a peak value. Also, a read address signal is switched over by an address inversion section of a simple constitution so that blocks of two kinds of magnitudes, “1” and “1/{square root over (2)}”, of the impulse response storage section are not accessed simultaneously.

Abstract: A jitter-tolerant signal receiver and a method of designing a jitter-tolerant signal receiver requiring only three D flip-flops. The jitter-tolerant signal receiver receives an input signal of a first clock domain and outputs a sampling event signal of a second clock domain in a communication system. The jitter-tolerant signal receiver includes a first D flip-flop, a second D flip-flop, and a third D flip-flop. The first D flip-flop receives the input signal at a first input terminal and a first clock at a first clock terminal and outputs a first event signal at a first output terminal. The second D flip-flop receives a high level signal at a second input terminal and the first event signal at a second clock terminal and outputs a second event signal at a second output terminal. The third D flip-flop for receives the second event signal at a third input terminal and a second clock of the second domain at a third clock terminal, and outputs the sampling event signal at a third output terminal.

Abstract: A signal processing method is described for processing a signal transmitted via a transmission channel. The method comprising the steps of: receiving (S11) a plurality of samples of the signal; analyzing (S12) the amplitude of a subset of the received samples; and estimating (S13) the variance of the signal based on the amplitude of the subset of the received samples. A corresponding signal processing device is also described. Thus, with the present invention it is possible to estimate the variance on the basis of the amplitude of the received signal. In consequence, no information about channel impulse response or training sequence is required.

Abstract: The present disclosure discloses a method and apparatus for slicing data, or “squaring up” a signal such as the output of a wireless receiver demodulator for proper interface with conventional digital logic circuits. The method involves the receiving of an input signal, the generation of a reference level, the comparison of the input signal to the reference level, and the measurement and storage of the reference level. The reference level is generated by applying the input signal to a filter, which has been previously set to an initial condition. The reference level is measured at a predetermined point in a receive data frame, and is maintained at the desired level throughout the remainder of the frame. After a frame has been received, the reference level is stored if the frame data output from the data slicer contained no errors.

Abstract: An adaptive quadrature amplitude modulation (“QAM”) decoding system for use in, for example, high speed, bandwidth efficient QAM communication systems includes a circuit that adaptively adjusts gain and voltage bias and provides adaptive equalization feedback based on the same signal used to decode the QAM symbols.

Abstract: A decoding method and apparatus, using the Viterbi algorithm for selecting survivor paths terminating on each trellis state, applied for realization of a shared channel decoder (SCD). The shared channel decoder include a branch metric calculator for calculating branch metrics Bt, a plurality of ACS units for computing and exchanging new path metrics &Ggr;t and survivor paths Et, a memory (RAM) for storing new path metrics &Ggr;t and survivor paths Et, and a memory (RAM) for storing previous path metrics &Ggr;t−1 and previous survivor paths Et−1. The branch metrics Bt is the set of branch metrics for decoding step t (e.g., for a code rate of ½, Bt={Bt,00, Bt,01, Bt,10, Bt,11}), the path metrics &Ggr;t is the set of S survivor metrics {&ggr;t,1, &ggr;t,2, . . . , &ggr;S} at decoding step t and the survivor paths Et is the set of S survivor metrics {Et,1,Et,2, . . . , Et,S} where S is the number of decoder states.

Abstract: A method for estimating and compensating for a fading communications channel includes the steps of generating matched filter data from a received data burst, interpolating between reference symbols to generate a fading channel estimate from the matched filter data, applying a phase correction to the matched filter data from the fading channel estimate to recover free data from the matched filter data, and performing decision feedback on the free data to improve the fading channel estimate.

Abstract: For enabling a stable clock signal to be extracted from even an input signal of which the duty factor is made worse, there is presented a clock extraction circuit applicable to an optical signal receiver equipped in an apparatus for use in the optical data communication. The clock extraction circuit includes a rising edge differential circuit (12) for differentiating the input signal at the rising edge thereof, a first monostable multivibrator (13) for processing the output from the differential circuit (12), a second monostable multivibrator (14) for processing the output from the first monostable multivibrator (13), an OR gate (15) for carrying out the logical OR between the output signals from the first and second monostable multivibrators (13) and (14) and circuitry for variably varying output pulse width, which processes the result of the logical OR.

Abstract: Recapture time and frequency disturbance behavior at the time of switching a transmission line extracted clock from an active clock to a standby clock are improved for a PLL circuit which is placed after a clock selection circuit. Phase difference is detected between a reference clock generated by the PLL circuit from a selected clock and a clock extracted from a standby transmission line and, based on the detected phase difference, the phase of the standby clock to be supplied to the clock selection circuit is adjusted and brought close to the phase of the reference clock. The clock phase adjustment is accomplished by generating a plurality of clocks with different phases using a delay element, and by selecting one of them in accordance with the detected phase difference.

Abstract: The present invention provides a simple smaller-sized elastic integrated circuit having a lower power, to which data synchronized with a first clock is input and which outputs data synchronized with a second clock. The elastic integrated circuit includes a read address counter which operates with an internal clock to output a read address count value; a delay circuit to which the read address count value is input and which delays and outputs the read address count value by a predetermined time period; a write address counter which operates using the read address count value output from the delay circuit with a clock externally input so as to output a write address count value; and a memory circuit which writes data input thereto by the write address count value and reads data written therein by the read address count value.

Abstract: A lock detector is described for detecting a difference between the frequencies of a first and a second input signal. The lock detector includes first and second beat generators configured to generate corresponding beat signals based on the first and second input signals. The second beat signal is phase shifted relative to the first beat signal. A chatter elimination module combines the two chattery beat signals to produce a third corresponding beat signal that is substantially free of chatter. Using this clean beat signal and either of the input signals, a lock detection module produces a lock detection signal, which indicates whether the difference between the frequencies of the first and second input signals is within a prescribed tolerance.

Abstract: A clock identification and reproduction circuit which synchronizes a clock signal with an input signal includes a voltage controlled generator for generating a clock signal, a phase comparator for detecting a phase difference between an input signal and a clock signal to generate a phase difference signal according to the phase difference, and a filter for synchronizing a clock signal of the voltage controlled generator in response to a phase difference signal, in which the phase comparator generates a phase difference signal when a specific pulse waveform of a pulse of an input signal changes.

Abstract: A method of producing an isotope comprising directing electrons at a converting material coated with a coating material, the coating material having an atomic number of n, whereby interaction of the electrons with the converting material produces photons, and whereby the photons produced interact with the coating material to produce an isotope having an atomic number of n−1. In preferred embodiments, the converting material is Tungsten, the coating material having an atomic number of n is Radium-226, and the isotope having an atomic number of n−1 is Radium-225.

Abstract: The contents of a container 1 are non-intrusively monitored by probing the container with an ultrasonic signal, and measuring changes in the ultrasound signature of the received signal after the signal has passed through the contents of the container.

Abstract: An apparatus and process for determining and displaying a helical artifact index to a system operator are provided. The HAI is determined by acquiring and processing imaging data of a phantom. The HAI is then displayed to the operator on a console so that the operator may, if necessary, reset the scanning parameters or select a new scanning protocol that will result in a reconstructed image of a subject having reduced artifact presence. By providing a likelihood of artifact presence to the system operator, the present invention eliminates the need for the operator to recall those scanning profiles that are susceptible to high artifact presence.

Abstract: A method for testing a surface includes finding respective first and second critical angles for total external reflection of radiation from an area of the surface at first and second wavelengths. The first and second critical angles are compared to determine an orientation of a tangent to the surface in the area.

Abstract: A high torque/high speed brushless DC motor system for controlling both the speed and torque of the motor including a rotor and a stator, the stator of the motor including a first, second and third winding. The system further includes means for sensing the position of the rotor and means for selectively configuring the first, second and third windings of the stator in a wye connection when the speed of the motor is less than a predetermined value and configuring the windings in a delta connection when the speed of the motor is greater than the predetermined value.

Abstract: A telephony communication system includes a private network with multiple telephony devices that couples to the public switched telephone network (PSTN). During emergency calls from devices in the private network (such as 911 calls), elements of the private network may provide enhanced services. In response to an appropriate request during the emergency call, the private network may supply detailed location information of the calling device to the operator within the emergency call. The private network may further supply relevant personal information for a user associated with the calling device to the emergency operator during the call. The private network may supply the location information and/or personal information to other personnel, such as an emergency access point or private emergency response personnel. Private network may further conference private emergency response personnel into emergency calls between managed telephony devices and governmental emergency response personnel.