Construct · 2 fields · 2 citations

Where does guard collide?

One name. Different field. Different construct. One map.

● jingle · one word, two constructs Nearest construct by meaning·not indexed
guard2 CONSTRUCTSGuarded commandDIJKSTRA · 1975Guard intervalCIMINI · 1985

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1975Guarded command1985Guard interval
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Computer science

A boolean condition that gates whether a statement may run

In computer science a guard is a boolean condition attached to a statement or clause so that the statement is eligible to execute only when the guard evaluates to true. Dijkstra's 1975 Guarded commands, nondeterminacy and formal derivation of programs introduced guarded commands as the basis for a small nondeterministic language in which one of the clauses whose guards hold is chosen to run, giving a clean calculus for reasoning about program correctness. The referent is a logical precondition that governs control flow, and it has nothing to do with a fighter's leg control or an empty band of radio spectrum beyond the shared idea of something that gates passage.[1]

Unit
Whether the guard condition evaluates to true or false
Recovery means
Not applicable
Measured by
Evaluated as a boolean predicate over the current program state

Telecommunications

An empty gap that keeps signals from smearing into each other

In digital communications a guard interval (or guard band) is a deliberately inserted gap (in time between successive symbols, or in frequency between channels) that absorbs delay spread and leakage so that one transmission does not corrupt the next. Cimini's 1985 Analysis and Simulation of a Digital Mobile Channel Using Orthogonal Frequency Division Multiplexing showed how a guard interval between OFDM symbols suppresses intersymbol interference on a multipath mobile channel. The referent is a protective margin of unused signal space, measured in microseconds or hertz, and it is a different construct from a grappling position or a program's precondition, joined only by the meaning of keeping something at bay.[2]

Unit
The duration (in time) or bandwidth (in frequency) of the protective gap
Recovery means
Not applicable
Measured by
Set relative to the channel's delay spread and assessed by residual intersymbol or interchannel interference

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Nearby collisions

predicate3 fields · 3 citationsjingle · one word, three constructssubmission1 fields · 1 citationsanchor · a standalone constructleakage3 fields · 4 citationsjingle · one word, three constructs

References

  1. Dijkstra, E. W. (1975). Guarded commands, nondeterminacy and formal derivation of programs. Communications of the ACM, 18(8), 453–457. https://doi.org/10.1145/360933.360975
  2. Cimini, L. (1985). Analysis and simulation of a digital mobile channel using orthogonal frequency division multiplexing. IEEE Transactions on Communications, 33(7), 665–675. https://doi.org/10.1109/tcom.1985.1096357

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