Abstract: Disclosed is a system and method for generating quantitative imagery of demyelination in the spinal cord. The method includes acquiring a magnetization transfer weighted (MTw) MR image of the spinal column, identifying a reference region of interest within the image corresponding to cerebrospinal fluid (CSF), averaging the signal intensity corresponding to the reference region of interest, and computing a ratio, on a voxel-by-voxel basis, of the signal intensity of each voxel by the averaged reference signal intensity. In doing so, normalized MTw images are obtained such that detrimental artifacts such as motion-induced errors, coil loading, and RF coil sensitivity variations are obviated.

Abstract: A color frame identifier circuit generates a pseudo-subcarrier signal and compares the pseudo-subcarrier signal to a sliced color burst of at least one selected line in a video frame. Based on this comparison, a processing circuit determines the color frame.

Abstract: A method and apparatus for compiling a protocol data unit (PDU) having a predetermined length from at least one data block for transmission in a wireless communication system. At least one data block is designated for transmission. The data block is first stored in a memory. A data block information list and a data block address list are generated for the data block. The data block information list contains the length of the data block which is to be included within the PDU and the data block address list contains the memory address of data block which is to be included in the PDU. The PDU is then compiled utilizing the data block information list and the data block address list when the PDU is ready for transmission.

Abstract: An apparatus for viewing an object through falling liquid includes structure defining a chamber for at least partially containing the object. At least one transparent or translucent member further defines the chamber. A conduit defines at least one hole positioned such that the transparent or translucent member is between the falling water and the chamber. The object is thus viewable by an observer through the falling liquid, and the member protects the object from the falling liquid.

Abstract: A video processing system and method are provided for generating clock and timing signals from an incoming video signal. The system includes a timing reference circuit for generating a reference clock signal, a video format detector coupled to the reference clock signal and to synchronization data derived from the incoming video signal for generating a format signal indicating the format of the incoming video signal, and a clock and timing generator circuit coupled to the format signal and the reference clock signal for generating clock and timing signals that emulate the incoming video signal, and may be locked to the incoming video signal.

Abstract: A color frame identifier circuit generates a pseudo-subcarrier signal and compares the pseudo-subcarrier signal to a sliced color burst of at least one selected line in a video frame. Based on this comparison, a processing circuit determines the color frame.

Abstract: A video processing system and method are provided for generating clock and timing signals from an incoming video signal. The system includes a timing reference circuit for generating a reference clock signal, a video format detector coupled to the reference clock signal and to synchronization data derived from the incoming video signal for generating a format signal indicating the format of the incoming video signal, and a clock and timing generator circuit coupled to the format signal and the reference clock signal for generating clock and timing signals that emulate the incoming video signal, and may be locked to the incoming video signal.

Abstract: A passively shimmed open architecture magnetic resonance imaging magnet utilizing separated superconducting coil assemblies with open space between including means to obtain a uniform magnetic field in the open space by shaped ferromagnetic bands in the bore of the magnets, the shaping including an axial notch and circumferential holes for attaching passive shims.

Abstract: A method for using an underground mine communication system to effect minewide communication and an intrinsically safe current limiter circuit for insuring that electrical equipment in the system will not cause incendiary conditions. The underground mine communication system comprises a plurality of repeaters and medium frequency radios, including mobile, portable and personal-carried radios, coupled to electrical conductors and natural waveguides existing in the earth by tuned loop antennas. Messages transmitted by the radios are carried to the repeaters by the conductors or coal seam waves. The repeaters amplify, replicate and retransmit the message at two different frequencies for transmission of the message to a surface base station and to other radios in the system. A paging system, which has a separate set of repeaters, is also coupled to the network of electrical conductors and natural waveguides by tuned loop antennas. The paging system alerts miners to contact the surface base station.

Abstract: A method for using an underground mine communication system to effect minewide communication and an intrinsically safe current limiter circuit for insuring that electrical equipment in the system will not cause incendiary conditions. The underground mine communication system comprises a plurality of repeaters and medium frequency radios, including mobile, portable and personal-carried radios, coupled to electrical conductors and natural waveguides existing in the earth by tuned loop antennas. Messages transmitted by the radios are carried to the repeaters by the conductors or coal seam waves. The repeaters amplify, replicate and retransmit the message at two different frequencies for transmission of the message to a surface base station and to other radios in the system. A paging system, which has a separate set of repeaters, is also coupled to the network of electrical conductors and natural waveguides by tuned loop antennas. The paging system alerts miners to contact the surface base station.

Abstract: A subscription television system in which individual decoders are enabled to receive individually addressed messages is disclosed. The composite signal, including video and teletext, also comprises addressed packets which are detected by decoders and which indicate that a message addressed to a particular subscriber is forthcoming, and system control data. In a preferred embodiment, both addressed packets and teletext are encrypted. The addressed packet is decrypted using a decoder-specific code and a transmitted code, while the teletext message is decrypted using a decryption key contained in the system control data. The teletext message cannot be received until the addressed packet has been decrypted. Therefore, redundant levels of security are provided to the system. Messages for display to the user can be selected in response to user initiated commands, in response to decoder initiation, or in response to the transmitter.

Abstract: A subscription television system for distributing program material protected by copyright to subscribers comprises a transmitter including a data insertion circuit for inserting a control bit in a transmitted signal comprising other control data and the protected program material. A receiver of the system includes a memory for storing a pre-assigned subscriber identification. Upon receipt and identification of the control bit at the receiver, the receiver inserts the subscriber identification into the program material so that any unauthorized copy made of the program material may be found to include the subscriber identification.

Abstract: A method for using an underground mine communication system to effect minewide communication and an intrinsically safe current limiter circuit for insuring that electrical equipment in the system will not cause incendiary conditions. The underground mine communication system comprises a plurality of repeaters and medium frequency radios, including, mobile, portable and personal-carried radios, inductively coupled to electrical conductors and natural waveguides existing in the earth by tuned loop antennas. Messages transmitted by the radios are carried to the repeaters by the conductors or coal seam waves. The repeaters amplify, replicate and retransmit the message at two different frequencies for transmission of the message to a surface base station and to other radios in the system. A paging system, which has a separate set of repeaters, is also coupled to the network of electrical conductors and natural waveguides by tuned loop antennas. The paging system alerts miners to contact the surface base station.

Abstract: A communication system enabling transmission of individual subscriber teletext messages, audio and video to individual subscribers and permitting group communications of audio, video, teletext and data information from a single central subscriber location, such as a corporate head office to a plurality of satellite offices, such as field or sales offices of the corporation, is disclosed. A composite signal including the information to be transmitted as well as system wide, individual decoder and group decoder control signals is transmitted. The system-wide control signals include data germane to operation of each of the decoders of this system, including key information needed to decode the composite signal. The system-wide control data is transmitted at a first relatively high frequency. The group decoder information includes information permitting individual groups of decoders to receive information portion of the composite signal being transmitted at a given time.

Abstract: A subscription television system in which individual decoders are enabled to receive individually addressed messages is disclosed. The composite signal, including video and teletext, also comprises addressed packets, which are detected by decoders and which indicate that a message addressed to a particular subscriber is forthcoming, and system control data. The decoder detects an addressed packet addressed to itself, whereby it is enabled to select the appropriate teletext message and to display the same. In a preferred embodiment, both address packets and teletext are encrypted. The addressed packet is decrypted using a decoder-specific code and a system key transmitted as part of the system control data, while the teletext packet is decrypted using the system key, but cannot be received until the addressed packet has been decrypted. Therefore, redundant levels of security are provided to the system.