摘要:
A method, apparatus, and system are provided for implementing spin-torque oscillator sensing with an enhanced integrated demodulator for hard disk drives. The demodulator receives an input signal from a STO read sensor having an oscillation frequency ω related to the strength of the detected magnetic signal field. The demodulator includes a pair of mixers coupled to a quadrature reference oscillator with respective quadrature components cos(ω0t), and sin(ω0t) of the quadrature reference oscillator being mixed with a received input signal to form signals at the sum and difference frequencies, ω±ω0. Each of these mixer products is lowpass filtered by a respective a lowpass filter to remove the sum frequency components for providing a demodulator output signal that is directly proportional the STO oscillation frequency ω. The demodulator output signal is used for processing by data detection electronics.
摘要:
A catheter having an elongated shaft and a balloon on a distal shaft section, the elongated shaft comprising an outer tubular member, and an inner tubular member which has a bonded portion along which an outer surface of the inner tubular member is bonded to an inner surface of the outer tubular member. The inner tubular member has a proximal portion proximal to the bonded portion, and a distal portion distal to the bonded portion with higher axial compression stiffness and column strength than the proximal portion thereof. The catheter has improved trackability, axial collapse resistance, pushability, and crossability, for improved ability to position the balloon at a desired location in a patient's body lumen.
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.
摘要:
A method of catheter manipulation involves providing a catheter comprising a flexible shaft having a distal end shaped for accessing a target vessel. The method further involves selectably moving the shaft between a plurality of discrete positions of a first degree-of-freedom defined relative to the flexible shaft, restraining a motion of the shaft in the first degree-of-freedom at each position of the plurality of discrete positions, and moving the flexible shaft through a second degree-of-freedom defined relative to the flexible shaft at each position of the plurality of discrete positions. Moving the flexible shaft through the second degree-of-freedom results in a controllable sweeping motion at the distal end of the flexible shaft.
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:
A bifurcation stent delivery catheter includes a first branch balloon, a second branch balloon adjacent the first branch. A centering balloon is optionally disposed distal of the second branch balloon. The balloons are coupled by a coupling device to a main shaft of a catheter. The coupling device allows axial forces to be transmitted from the main shaft to the balloons while allowing the balloons to rotate axially relative to the main shaft with ease. The coupling device functions as an axial rotational joint. The coupling device can have a flexible tubular member that connects the balloons to the main shaft, the tubular member having a torsional flexibility greater than that of the main shaft. The coupling device can have a tubular wall having a cut extending circumferentially around the tubular wall and protective boot covering the cut. The coupling device can have a wound member that allows the axial rotation.
摘要:
A data storage device can be validated through a network before the data storage device can be operated. In one embodiment, the data storage device includes a magnetic disk and a head assembly having a read/write head which reads and writes data from/on the magnetic disk. The data storage device further includes a controller configured to control the head assembly to read/write data to/from the magnetic disk. In addition, the data storage device includes a secure area of the magnetic disk containing a private key. The private key is one of a pair of cryptographically linked keys and the other of the cryptographically linked keys is a public key. Furthermore, the data storage device includes a memory located within the controller containing an auxiliary key, the auxiliary key being used to encrypt or decrypt the private key.
摘要:
Two levels of error correction decoding are performed using first and second level decoders. A composite code formed by combining an inner component code and an outer component code can be used to decode the data and correct any errors. Performing two level decoding using a composite code allows the size of the inner parity block to be reduced to a single Reed-Solomon symbol while keeping a good code rate. The first level decoder generates soft information. The soft information can indicate a most likely error event for each possible syndrome value of the inner component code. The soft information can also include error metric values for each of the most likely error events. The second level decoder generates corrected syndrome values based on the soft information using the outer component code. The most likely trellis path that corresponds to the corrected syndrome values is then selected.
摘要:
A composite polymer fiber comprises a polymer filler material and a plurality of polymer scattering fibers disposed within the filler material. At least one of the filler material and the scattering fibers is formed of a birefringent material. The refractive indices of the filler material and the scattering fibers can be substantially matched for light incident in a first polarization state on the composite polymer fiber and unmatched for light incident in an orthogonal polarization state. The scattering fibers may be arranged to form a photonic crystal within the composite fiber. The composite fibers may be extruded and may be formed into a yarn, a weave or the like. If the filler material is soluble, it may be washed out of the yarn or weave, and the scattering fibers may then be infiltrated with a resin that is subsequently cured.
摘要:
Embodiments of the present invention provide a system and a method for generating warranty and pricing information for one or more data storage apparatuses. In one embodiment, a system for processing status parameters of one or more data storage apparatuses comprises at least one host system configured to retrieve one or more status parameters of one or more data storage apparatus; a vendor system; and a network coupled with the at least one host system and the vendor system. The at least one host system is configured to send the one or more status parameters via the network to the vendor system. The vendor system is configured to use the one or more status parameters to generate any one or more of warranty information, pricing information, and design improvement information for the data storage apparatus.