In reliability engineering, dual modular redundancy (DMR) is when components of a system are duplicated, providing redundancy in case one should fail. It is particularly applied to systems where the duplicated components work in parallel, particularly in fault-tolerant computer systems.

Redundancy in United Kingdom law concerns the rights of employees if they are dismissed for economic reasons in UK labour law.

<algorithm> (CRC or "cyclic redundancy code") A number derived from, and stored or transmitted with, a block of data in order to detect corruption. By recalculating the CRC and comparing it to the value originally transmitted, the receiver can detect some types of transmission errors. A CRC is more complicated than a checksum. It is calculated using division either using shifts and exclusive ORs or table lookup (modulo 256 or 65536). The CRC is "redundant" in that it adds no information. A single corrupted bit in the data will result in a one bit change in the calculated CRC but multiple corrupted bits may cancel each other out. CRCs treat blocks of input bits as coefficient-sets for polynomials. E.g., binary 10100000 implies the polynomial: 1*x^7 + 0*x^6 + 1*x^5 + 0*x^4 + 0*x^3 + 0*x^2 + 0*x^1 + 0*x^0. This is the "message polynomial". A second polynomial, with constant coefficients, is called the "generator polynomial". This is divided into the message polynomial, giving a quotient and remainder. The coefficients of the remainder form the bits of the final CRC. So, an order-33 generator polynomial is necessary to generate a 32-bit CRC. The exact bit-set used for the generator polynomial will naturally affect the CRC that is computed. Most CRC implementations seem to operate 8 bits at a time by building a table of 256 entries, representing all 256 possible 8-bit byte combinations, and determining the effect that each byte will have. CRCs are then computed using an input byte to select a 16- or 32-bit value from the table. This value is then used to update the CRC. Ethernet packets have a 32-bit CRC. Many disk formats include a CRC at some level. (1997-08-02)

cyclic redundancy check

A cyclic redundancy check (CRC) is an error-detecting code commonly used in digital networks and storage devices to detect accidental changes to digital data. Blocks of data entering these systems get a short check value attached, based on the remainder of a polynomial division of their contents.

In mathematics, any vector space V has a corresponding dual vector space (or just dual space for short) consisting of all linear forms on V, together with the vector space structure of pointwise addition and scalar multiplication by constants.

In a dual-thrust solid propellant rocket engine, the propellant mass is composed of two different types (densities) of fuel. In the case of a tandem dual-thrust motor, the fuel closest to the rocket nozzle burns fast and the fuel further into the motor's body burns slower.

In a dual-thrust solid propellant rocket engine, the propellant mass is composed of two different types (densities) of fuel. In the case of a tandem dual-thrust motor, the fuel nearest to the rocket nozzle burns fast, and the fuel further into the motor's body burns slower.

Dual wielding is the technique of using two weapons, one in each hand for training or combat. It is not a common combat practice.

In mathematics, the dual bundle is an operation on vector bundles extending the operation of duality for vector spaces.