摘要:
Secure data is written to a disk during manufacture in such a way that it can be read but not copied. Methods include writing triangular transitions or very slow transitions from positive magnetic to negative magnetic and then erasing the negative parts to yield a code that consists of positive read back amplitudes only. Or, high frequency transitions can be written during servo writing.
摘要:
A data recording system, such as a magnetic recording hard disk drive, has a recording medium in which the data tracks have pseudo-random binary sequences for the servo information used to control the position of the recording head. A first pseudo-random binary sequence (PRBS) and a second PRBS identical to the first PRBS but shifted by a portion of the period of the first PRBS are located between the track boundaries in alternating tracks in a first region of the servo pattern and between the track centers in alternating tracks in a second region spaced along the track from said first region. A servo decoder has two correlators, one for each PRBS. Each correlator outputs a dipulse when its PRBS repeats. The difference in amplitude of the dipulses represents the head position signal. The dipulses also control the amplifier for the signal read back by the head and the timing of the track identification (TID) detector.
摘要:
A data recording medium, such as a magnetic recording hard disk, has data tracks with pseudo-random binary sequences for the servo information used to control the position of the recording head in the disk drive. A first pseudo-random binary sequence (PRBS) and a second PRBS identical to the first PRBS but shifted by a portion of the period of the first PRBS are located between the track boundaries in alternating tracks in a first region of the servo pattern and between the track centers in alternating tracks in a second region spaced along the track from said first region. A servo decoder in the disk drive has two correlators, one for each PRBS. Each correlator outputs a dipulse when its PRBS repeats. The difference in amplitude of the dipulses represents the head position signal. The dipulses also control the amplifier for the signal read back by the head and the timing of the track identification (TID) detector.
摘要:
A sensor interface is provided with a number of sensor inputs and a number of client inputs. The client inputs are configured to receive a number of data requests from a number of clients. The number of data requests include at least one data request that specifies a particular type of data to be returned, without identifying a particular physical sensor to be used in acquiring the particular type of data. A processor is configured to i) determine what sensor data can be used to satisfy the number of data requests, ii) configure ones of the sensor inputs to receive sensor data from a number of physical sensors, and iii) if possible, satisfy the number of data requests using the received sensor data. Methods and apparatus pertaining to such a sensor interface are also disclosed.
摘要:
Various embodiments of the present invention provide systems and methods for a multi-tier data processing system. For example, a data processing system is disclosed that includes an input operable to receive data to be processed, a first data processor operable to process at least some of the data, a second data processor operable to process a portion of the data not processed by the first data processor, wherein the first data processor has a higher throughput than the second data processor, and an output operable to yield processed data from the first data processor and the second data processor.
摘要:
An apparatus and method for controlling inflation pressure and pressurization rate of a balloon during deployment of a stent or scaffold is disclosed.
摘要:
Techniques are provided for identifying the servo sectors in a track on a data storage device. A data storage device identifies the servo sectors in a track by reading distributed index bits from multiple servo sectors in a track. The data storage device analyzes only one index bit from each servo sector to identify the index of a track. In some embodiments, the index of a track can be identified after examining the index bits stored in a particular number of consecutive servo sectors, even in the presence of errors. The index bits in each track can have an error tolerance with a minimum Hamming distance greater than one. In other embodiments, a data storage device compares a sliding window of the index bits read from the servo sectors to all possible N-bit vectors that exist within a pattern of the index bits stored on a track.
摘要:
The present disclosure describes a method and apparatus for guide catheterization. In one embodiment, a guiding catheter system includes a flexible shaft having a distal end shaped for accessing a target vessel. A handle assembly is movably coupled to the flexible shaft. The flexible shaft is selectably movable between a plurality of discrete positions of a first degree-of-freedom defined relative to the flexible shaft. The flexible shaft restrained in the first degree-of-freedom at each position of the plurality of discrete positions. The flexible shaft movable through a predetermined displacement of a second degree-of-freedom defined relative to the flexible shaft at each position of the plurality of discrete positions. Motion of the flexible shaft relative to the handle assembly results in a controllable sweeping motion at the distal end of the flexible shaft.
摘要:
WORM safeguards are provided in a magnetic disk drive in which the disks are pre-magnetized or pre-recorded such that all magnetic domains on each recording surface are completely aligned pointing in the same direction. A special write head which can magnetically write only in the direction opposite to the pre-magnetization orientation is also provided.