摘要:
A magnetic-resonance imaging apparatus has superconducting magnets for generating a large uniform magnetic field within a predetermined volume. Within that volume, coils for generating magnetic field gradients are supported on a bobbin, enabling an object within the bobbin to be investigated. The coils on the bobbin are subject to forces but are rigidly connected to the bobbin. Therefore, energy is transmitted to the bobbin which can cause the bobbin to vibrate and so generate noise. To dissipate that energy, the coils are attached to tubes, or other hollow members, on the bobbin, which tubes or hollow members contain movable bodies such as particulate material. The energy due to the forces on the coils cause the movable bodies to move and collide, so dissipating the energy and reducing the noise.
摘要:
A magnetic resonance imaging apparatus includes a magnet for generating a static magnetic field, a gradient coil for generating a gradient magnetic field in a measurement space, and a vibration damping means which includes a container and granular material disposed in the container. The vibration damping means is installed with a supporting bolt between the gradient coil and a supporting means. Since the gradient coil is supported at a constant position without any vibration and deformation, the magnetic resonance imaging apparatus generates an accurate image signal without any acoustic noise.
摘要:
The invention designed to improve the precision in determining the position of the magnetic head and to enable more stable maintenance of the gap between the transducer and the recording disk is characterized in that the flange provided to the transducer supporting arm is made lower in height on the rigid arm side than on the magnetic head side.
摘要:
An apparatus for supporting and reciprocating a magnetic head slider above a rotating magnetic disk comprises a carrying arm having a free end, a flexible base connected at one end thereof to the free end of the supporting arm, a pair of flexible fingers extending from the other end of the flexible base parallel to an axis of the carrying arm and defining therebetween a space, a traverse bar connecting two free ends of the fingers, and a flexible tongued member on which the magnetic head slider to be mounted, one end of the tongued member being connected to the traverse bar and the other end thereof extending into the space with gaps between the tongued member and the fingers and the base. A reduced part of a minimum cross-section is provided in each of the fingers. The reduced part is located between the one end of the tongued member and a center between the one end of the tongued member and the other end of the base.
摘要:
A suspension mount apparatus for a transducer used in a magnetic memory for recording and reproduction, is characterized in that the points, at which a rigid arm and a magnetic head/arm assembly supported by the rigid arm are connected to each other, are provided within a region in which the rigidity of the connecting points vary at constant rates with respect to the distances between the connecting points and the borderlines between the rigid arm and the assembly.
摘要:
A thixotropic material is charged in a container. The container also holds a movable member which is placed in the thixotropic material so as to stir the thixotropic material. A force transmitting element is connected to the movable member. When an object, the vibration of which is to be controlled, is out of resonance, the amplitude of vibration is so small that the thixotropic material is in a gel state, thus presenting a comparatively large spring constant for the vibration control apparatus. As the excitation frequency is increased towards the resonance range, the amplitude of vibration is increased correspondingly, so that the movable member stirs the thixotropic material to generate stress in the latter, whereby the phase of the thixotropic material is changed from gel to sol. Consequently, the natural frequency of the vibration system, including the object and the vibration control apparatus, is lowered, thus averting resonance. It is thus possible to obtain vibration restraining or control effect over a wide range of excitation frequencies.
摘要:
To provide a charging member which suppresses the generation of density nonuniformity in an electrophotographic image caused by charge nonuniformity due to adhesion of charged substances, such as toner particles. There is provided a charging member which has a surface layer, the surface layer includes conductive zinc oxide whiskers each formed of a nuclear portion and four needle crystal portions extending radially outward therefrom, and the needle crystal portions are exposed to form convex portions of a surface of the surface layer.
摘要:
Provided is a migration system considering security authentication levels and data protection strength levels of the both security devices between which data is migrated. A first terminal includes a mechanism for protecting data by a private key in the public key method held by TPM, and a second terminal includes a key in the private key method encrypted by the private key in the public key method held by TPM and a mechanism for protecting the data by the key. A Migration Authority holds a security policy table describing a security policy and judges whether data movement from the first terminal to the second terminal is enabled according to the security policy table.
摘要:
To provide a program conversion device capable of executing a program that includes a secret operation using secret information without exposure of the secret information in a memory. In an execution program generation device, with respect to an original program that includes the secret operation, a combining function generation unit generates combining function processing for applying a bitwise self-dual function to an input value, a split secret information generation unit generates pieces of split secret information by performing an inverse operation of the self-dual function, a program conversion unit generates pieces of split secret operation processing each for performing the operation between each bit value of the operand information and a corresponding bit value of a different piece of the split secret information, and replaces the secret operation processing with the pieces of the split secret operation processing and the combining function processing.
摘要:
A tamper detection device detects tampering with a program loaded to memory, at high speed and without compromising the safety. Prior to loading of a program, a dividing-size determining unit 12 determines a block size based on random number information, a dividing unit 13 divides the program by the block size into data blocks, and a first conversion unit 14 converts, by conducting a logical operation, the data blocks into intermediate authentication data no greater than the block size, and a second conversion unit 15 conducts a second conversion on the intermediate authentication data to generate authentication data. The authentication data and the block size are stored. After the program loading, a program resulting from the loading is divided by the block size, followed by the first and second conversions to generate comparative data. The comparative data is compared with the authentication data to detect tampering of the loaded program.