Online Computer Terms Dictionary - C

continuous function

A function f : D -> E, where D and E are cpos, is continuous if it is monotonic and

	f (lub Z) = lub { f z | z in Z }

All additive functions (functions which preserve all lubs) are continuous. A continuous function has a least fixed point if its domain has a least element, bottom (i.e. it is a cpo or a "pointed cpo" depending on your definition of a cpo). The least fixed point is

	fix f = lub {f^n bottom | n = 0..infinity}

Continuous System Modeling Program

<simulation> (CSMP) A program for simulation of dynamics of continuous systems. CSMP is similar to CSSL.

["A Guide to Using CSMP - The Continuous System Modeling Program", Frank H. Speckhart et al, P-H 1976].

(1995-02-23)

Continuous System Simulation Language

<simulation> (CSSL) Versions include ACSL, HYTRAN, SL-I, S/360 and CSMP.

CSSL(Continuous System Simulation Language) versions I, II, III, IV and V have been commercially available since 1968. CSSL-I was developed for Jet Propulsion Labs in 1968. CSSL-III was widely distributed from 1969-1975. CSSL-IV (interactive version) was developed by R. Nilsen and ran on over 30 different computers. Currently CSSL-V is marketed by Simulation Services International and available on PCs and workstations.

["The SCi Continuous System Simulation Language (CSSL)", Simulation, 9(6), Dec 1967].

[URL?]

(2003-04-15)

continuous wave

<communications> (CW) A term from early radio history, when the spark gap method of transmission was replaced by vacuum-tube oscillators. A spark gap initiates a ringing, damped sinusoidal wave in a tuned circuit consisting of an inductor and capacitor. The energy in this circuit is constantly changing between the capacitor's electrostatic field and the inductor's magnetic field. The energy is then coupled, loosely (so as not to dampen the wave too quickly), to the radiating antenna.

In contrast, a vacuum-tube oscillator constantly adds energy to the tuned circuit, compensating for the amount coupled to the antenna, and the transmitted energy or "wave," is therefore "continuous".

Many (especially radio amateurs) continue to understand "CW" to mean transmission by means a signal of a single frequency which is either on or off (e.g. Morse code), as opposed to a carrier which varies continuously in amplitude, frequency or phase. Some would even call the former "unmodulated" even though turning on and off is actually an extreme form of amplitude modulation.

(1995-03-15)