International Business Machines Corporation

National Semiconductor Corporation

Infineon Technologies Ag

Roger Lee Miller

Curt Lee Cotner

Thomas P Harper

Mario Festag

Christian Carstens

Andreas Steffensen

Andreas Stockhausen

Timothy T Regan

Access control methods provide multilevel and mandatory access control for a database management system. The access control techniques provide access control at the row level in a relational database table. The database table contains a security label column within which is recorded a security label that is defined within a hierarchical security scheme. A user's security label is encoded with security information concerning the user. When a user requests access to a row, a security mechanism compares the user's security information with the security information in the row. If the user's security dominates the row's security, the user is given access to the row.

Row-level security in a relational database management system

An access control system provides multilevel and mandatory access control for a database management system. The access control systems provide access control at the row level in a relational database table. The database table contains a security label column within which is recorded a security label that is defined within a hierarchical security scheme. A user's security label is encoded with security information concerning the user. When a user requests access to a row, a security mechanism compares the user's security information with the security information in the row. If the user's security dominates the row's security, the user is given access to the row.

An access control system and access control methods provide multilevel and mandatory access control for a database management system. The access control techniques provide access control at the row level in a relational database table. The database table contains a security label column within which is recorded a security label that is defined within a hierarchical security scheme. A user's security label is encoded with security information concerning the user. When a user requests access to a row, a security mechanism compares the user's security information with the security information in the row. If the user's security dominates the row's security, the user is given access to the row.

An optical transceiver module includes an electro-optical transmission assembly and an electro-optical receiving assembly both mounted on a common printed circuit board and enclosed by a top shell and a bottom shell of an electromagnetically shielding transceiver module. The housing has optical connection openings and an electrical connection opening. The serial optical signals of a first Bit-rate of several Gbit/s and more are converted to serial electrical signals and are multiplexed to parallel electrical signals at a lower second Bit-rate. Reducing the Bit-rate and thus reducing the electromagnetic frequency reduces the risk of electromagnetic interference on the printed circuit main-board. The optical connection openings have a first and a second gasket for reducing the electromagnetic radiation emerging out of the housing through the optical connection openings. The electrical connection opening has a third gasket for reducing the electromagnetic radiation emerging out of the electrical connection opening.

Optical transceiver module

Digital circuits determine multiplicative inverses using look-up tables which, in response to an address signal, provide a signal indicating a multiplicative inverse. The look-up tables store values indicating inverses for numbers between 1 and 2. The circuit factors a value to be inverted as product a power of two and a factor between 1 and 2. An address signal indicating the factor is applied to the look-up table, and the look-up table provides a signal which indicates the inverse of the factor. The signal provided by the look-up table is then converted to the proper scale for the exponent N. Factoring and conversion may be accomplished with logical shifts so that no multiplier is required. The look-up table may be compressed by not storing bits of inverses, which are constant or only change once within the range of the look-up table and by only storing look-up values for every other number within the range of the look-up table. A code bit in each look-up table value permits generation of correct inverses for values not stored.

Circuit and method for determining multiplicative inverses with a

A voltage regulator, a device driver, and a warning signal driver are provided on a single voltage regulator integrated circuit. The voltage regulator provides a regulated voltage for external logic such as a microcontroller. The device driver selectively turns on or turns off an external device such as a relay. The warning signal driver outputs a warning signal. The integrated circuit contains sensing circuits which sense if the output voltage is out of proper regulation. In the event of a malfunction, for example when the output voltage is outside a desired voltage range, the device driver shuts off the external device and the warning signal driver generates a warning signal. The integrated circuit may also receive signals from the external logic which cause the integrated circuit to shut off the device or to generate a warning signal.

Failsafe voltage regulator with warning signal driver

An anti-lock braking system includes a mechanism for releasing a brake and a digital circuit for determining a wheel velocity and controlling the mechanism to prevent the brake from locking. The digital circuit uses a look-up table which, in response to an address signal, provides a signal indicating a multiplicative inverse of a number between 1 and 2. The circuit receives a measured time for a wheel to move a fixed distance and factors the time as product a power of two and a factor between 1 and 2. An address signal indicating the factor is applied to the look-up table, and the look-up table provides a signal which indicates the inverse of the factor. The signal from the look-up table is then converted to the proper scale for the time. Factoring and conversion may be accomplished with logical shifts so that no multiplier is required. The look-up table may be compressed by not storing bits of inverses, which are constant or only change once within the range of the look-up table and by only storing look-up values for every other number within the range of the look-up table. A code bit in each look-up table value permits generation of correct inverses for values not stored.

Anti-lock braking system containing look-up table for determining wheel

An anti-lock braking system includes three integrated circuits (an integrated voltage regulator and two different microcontrollers) which perform different functions but share the tasks of detecting malfunctions and shutting down the system when malfunctions are detected. The two different microcontrollers perform different functions, have different circuitry, and execute different software. Typically, a first microcontroller receives wheel sensor signals, calculates wheel velocities and accelerations, and operates mechanical devices which control braking. A second microcontroller executes the main anti-lock braking software and determines from the velocities and accelerations when brakes should be released. All of the integrated circuits monitor each other and the other elements of the anti-lock braking system to detect malfunctions. Multiple shut down methods are provided so that a single chip failure can be safely handled. The three integrated circuits can be fabricated using different device technologies and design rules so that the operating environment of the anti-lock braking system is less likely to cause simultaneous failures in multiple integrated circuits.

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San Jose, CA, United States of America

Roger Lee Miller