TERMIUM Plus®
From: Translation Bureau
On social media
Consult the Government of Canada’s terminology data bank.
THRESHOLD CONTRAST [5 records]
Record 1 - internal organization data 2014-05-05
Record 1, English
Record 1, Subject field(s)
- Modelling (Mathematics)
- Epidemiology
Record 1, Main entry term, English
- susceptible-infected-susceptible model
1, record 1, English, susceptible%2Dinfected%2Dsusceptible%20model
correct
Record 1, Abbreviations, English
Record 1, Synonyms, English
- SIS model 2, record 1, English, SIS%20model
correct
Record 1, Textual support, English
Record number: 1, Textual support number: 1 CONT
The susceptible-infected-susceptible(SIS) model of Weiss and Dishon is one of the simplest models of endemic infections. The model describes the evolution of an infection in a fixed population, with no restriction on the possibility of reinfection of a previously infected and now recovered individual. This is in contrast to the venerable susceptible-infection-recovered(SIR) model, where reinfection is not permitted. Both models exhibit a threshold value of the infectivity, below which the infection immediately dies out. Below the threshold, where only a tiny fraction of the population is impacted, the two models have essentially equivalent statistical properties. Above the threshold, in the SIR model, the infection is self-limiting, since in a fixed population the number of potential new victims, the susceptible pool, is monotonically decreasing in size. The SIS model, on the other hand, describes an endemic infection which can(above the threshold) persist indefinitely, at least at the deterministic level. Thus, the statistics of infection size in the two models above the threshold are very different. 1, record 1, English, - susceptible%2Dinfected%2Dsusceptible%20model
Record 1, Key term(s)
- susceptible-infectious-susceptible model
- susceptible-infection-susceptible model
Record 1, French
Record 1, Domaine(s)
- Modélisation (Mathématique)
- Épidémiologie
Record 1, Main entry term, French
- modèle SIS
1, record 1, French, mod%C3%A8le%20SIS
correct, masculine noun
Record 1, Abbreviations, French
Record 1, Synonyms, French
Record 1, Textual support, French
Record number: 1, Textual support number: 1 CONT
On considère une population close et on modélise la propagation d’une maladie infectieuse dans cette population. On suppose que les individus composant la population peuvent être dans l’un de deux états : ils sont susceptibles (à la maladie) s’ils n’ont pas contracté la maladie, et infectieux s’ils ont contracté la maladie et qu’ils la propagent. Cela définit donc deux compartiments, l’objet de la modélisation étant de décrire l’évolution du nombre d’individus dans chaque compartiment [...] 2, record 1, French, - mod%C3%A8le%20SIS
Record number: 1, Textual support number: 2 CONT
Ce modèle est appelé modèle SIS, pour susceptible-infectieux-susceptible. 2, record 1, French, - mod%C3%A8le%20SIS
Record 1, Spanish
Record 1, Textual support, Spanish
Record 2 - internal organization data 2004-10-28
Record 2, English
Record 2, Subject field(s)
- Atmospheric Physics
Record 2, Main entry term, English
- visual range
1, record 2, English, visual%20range
correct
Record 2, Abbreviations, English
Record 2, Synonyms, English
- meteorological visual range 2, record 2, English, meteorological%20visual%20range
correct
Record 2, Textual support, English
Record number: 2, Textual support number: 1 DEF
Distance at which the contrast of a given object with respect to its background is just equal to the contrast threshold of an observer. 3, record 2, English, - visual%20range
Record 2, French
Record 2, Domaine(s)
- Physique de l'atmosphère
Record 2, Main entry term, French
- portée visuelle
1, record 2, French, port%C3%A9e%20visuelle
correct, feminine noun
Record 2, Abbreviations, French
Record 2, Synonyms, French
Record 2, Textual support, French
Record number: 2, Textual support number: 1 DEF
Distance à laquelle le contraste entre un objet donné et son arrière-plan atteint la valeur du seuil de contraste propre à l'observateur. 2, record 2, French, - port%C3%A9e%20visuelle
Record 2, Key term(s)
- portée visuelle en météorologie
Record 2, Spanish
Record 2, Campo(s) temático(s)
- Física de la atmósfera
Record 2, Main entry term, Spanish
- alcance visual
1, record 2, Spanish, alcance%20visual
masculine noun
Record 2, Abbreviations, Spanish
Record 2, Synonyms, Spanish
Record 2, Textual support, Spanish
Record number: 2, Textual support number: 1 DEF
Distancia a la que el contraste entre un objeto y su fondo es exactamente igual al umbral de contraste visual de un observador. 1, record 2, Spanish, - alcance%20visual
Record 2, Key term(s)
- alcance visual en meteorología
Record 3 - internal organization data 2002-02-21
Record 3, English
Record 3, Subject field(s)
- Signalling and Illumination (Air Transport)
Record 3, Main entry term, English
- visual threshold of luminance contrast
1, record 3, English, visual%20threshold%20of%20luminance%20contrast
correct, officially approved
Record 3, Abbreviations, English
Record 3, Synonyms, English
Record 3, Textual support, English
Record number: 3, Textual support number: 1 DEF
The smallest luminance contrast that permits an object to be visually identified with an accepted degree of clarity. 1, record 3, English, - visual%20threshold%20of%20luminance%20contrast
Record number: 3, Textual support number: 1 OBS
visual threshold of luminance contrast : term and definition officially approved by the International Civil Aviation Organization(ICAO). 2, record 3, English, - visual%20threshold%20of%20luminance%20contrast
Record 3, French
Record 3, Domaine(s)
- Signalisation (Transport aérien)
Record 3, Main entry term, French
- seuil visuel de contraste de luminance
1, record 3, French, seuil%20visuel%20de%20contraste%20de%20luminance
correct, masculine noun, officially approved
Record 3, Abbreviations, French
Record 3, Synonyms, French
Record 3, Textual support, French
Record number: 3, Textual support number: 1 DEF
[...] contraste de luminance le plus faible qui permet d'identifier visuellement un objet avec une clarté acceptable. 1, record 3, French, - seuil%20visuel%20de%20contraste%20de%20luminance
Record number: 3, Textual support number: 1 OBS
seuil visuel de contraste de luminance : terme et définition uniformisés par l'Organisation de l'aviation civile internationale (OACI). 2, record 3, French, - seuil%20visuel%20de%20contraste%20de%20luminance
Record 3, Spanish
Record 3, Campo(s) temático(s)
- Señales e iluminación (Transporte aéreo)
Record 3, Main entry term, Spanish
- umbral visual de contraste luminoso
1, record 3, Spanish, umbral%20visual%20de%20contraste%20luminoso
correct, masculine noun, officially approved
Record 3, Abbreviations, Spanish
Record 3, Synonyms, Spanish
Record 3, Textual support, Spanish
Record number: 3, Textual support number: 1 DEF
Contraste de luminancia mínimo que permite identificar visualmente un objeto con un grado aceptable de claridad. 1, record 3, Spanish, - umbral%20visual%20de%20contraste%20luminoso
Record number: 3, Textual support number: 1 OBS
umbral visual de contraste luminoso: término y definición aceptados oficialmente por la Organización de Aviación Civil Internacional (OACI). 2, record 3, Spanish, - umbral%20visual%20de%20contraste%20luminoso
Record 4 - internal organization data 1987-05-14
Record 4, English
Record 4, Subject field(s)
- Optics
Record 4, Main entry term, English
- visibility level
1, record 4, English, visibility%20level
correct
Record 4, Abbreviations, English
Record 4, Synonyms, English
Record 4, Textual support, English
Record number: 4, Textual support number: 1 DEF
the ratio of equivalent contrast to threshold contrast. 1, record 4, English, - visibility%20level
Record 4, French
Record 4, Domaine(s)
- Optique
Record 4, Main entry term, French
- niveau de visibilité
1, record 4, French, niveau%20de%20visibilit%C3%A9
masculine noun
Record 4, Abbreviations, French
Record 4, Synonyms, French
Record 4, Textual support, French
Record number: 4, Textual support number: 1 DEF
rapport du contraste équivalent au contraste seuil. 1, record 4, French, - niveau%20de%20visibilit%C3%A9
Record 4, Spanish
Record 4, Textual support, Spanish
Record 5 - internal organization data 1982-11-15
Record 5, English
Record 5, Subject field(s)
- Aeroindustry
Record 5, Main entry term, English
- pseudo-noise
1, record 5, English, pseudo%2Dnoise
correct
Record 5, Abbreviations, English
Record 5, Synonyms, English
Record 5, Textual support, English
Record number: 5, Textual support number: 1 CONT
By contrast, the performance of an FM system deteriorates rapidly after falling below a certain threshold. Phase-modulated signals, when properly processed, require less bandwidth and can be coded using pseudo-noise and spread-spectrum techniques, thus reducing the chance of enemy detection. 1, record 5, English, - pseudo%2Dnoise
Record 5, French
Record 5, Domaine(s)
- Constructions aéronautiques
Record 5, Main entry term, French
- pseudo-bruit 1, record 5, French, pseudo%2Dbruit
Record 5, Abbreviations, French
Record 5, Synonyms, French
Record 5, Textual support, French
Record number: 5, Textual support number: 1 CONT
Les ingénieurs de Hughes ont découvert qu'avec cette méthode l'image de télévision s'affaiblit graduellement à mesure qu'augmente l'intensité du signal de brouillage, alors que les performances d'un système utilisant la technique FM se dégradent rapidement lorsqu'elles sont tombées au-dessous d'un certain seuil. Les signaux modulés en phase, lorsqu'ils sont convenablement traités, exigent une moins grande largeur de bande et peuvent être codés au moyen des techniques de pseudo-bruit et d'étalement de spectre, ce qui diminue les risques de détection par l'ennemi. 1, record 5, French, - pseudo%2Dbruit
Record 5, Spanish
Record 5, Textual support, Spanish
Copyright notice for the TERMIUM Plus® data bank
© Public Services and Procurement Canada, 2026
TERMIUM Plus®, the Government of Canada's terminology and linguistic data bank
A product of the Translation Bureau
Features
GCtranslate (available on the Government of Canada network only)
Use this artificial intelligence prototype to translate Government of Canada content up to and including Protected B. Available to employees of selected departments and agencies only.
Writing tools
The Language Portal’s writing tools have a new look! Easy to consult, they give you access to a wealth of information that will help you write better in English and French.
Glossaries and vocabularies
Access Translation Bureau glossaries and vocabularies.
- Date Modified:


