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Start Over Subject bimodality

1. Conditions for bimodality and multimodality of a mixture of two unimodal densities

Creator:
Došlá, Šárka
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
bimodality, unimodality, multimodality, and mixture of two unimodal distributions
Language:
English
Description:
Conditions for bimodality of mixtures of two unimodal distributions are investigated in some special cases. Based on general characterizations, explicit criteria for the parameters are derived for mixtures of two Cauchy, logistic, Student, gamma, log-normal, Gumbel and other distributions.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

2. Ecologically realistic modalities in arthropod supercooling point distributions

Creator:
Hawes, Timothy C., Bale, Jeffrey S., Convey, Peter, and Worland, Roger
Type:
article, model:article, and TEXT
Subject:
Cold hardiness, supercooling point, categories of cold hardiness, and bimodality
Language:
English
Description:
Modality in the supercooling points of cold tolerant but freezing intolerant terrestrial arthropods has proved a pragmatically reliable means of distinguishing between summer and winter cold hardiness in such species. This paper proposes an ecologically realistic method of modal analysis which may either be used in lieu of the traditional separation of supercooling points into "high" and "low" groups, or as a complementary assessment of the risk of freezing mortality. Instead of a posteriori determinations of modal break points, animal supercooling points are assigned a priori to one of four categories of cold hardiness: (1) summer cold-hardy; (2) semi-cold-hardy; (3) cold-hardy; and (4) winter cold-hardy. Each category is identified by the temperature range within which arthropods can be expected to freeze. The temperature ranges assigned to each category are based on a conservative, but realistic, assessment of the temperatures at which animals can be expected to freeze at a given point in the season. The approach has greater discriminatory power than traditional bimodal descriptors (i.e."summer" and "winter" cold-hardy), as well as allowing animal supercooling points to be related to the temperatures they actually experience in their habitats. Thus, for example, animals considered "summer" cold-hardy according to conventional analysis may actually be "semi-cold-hardy" with supercooling points well within the safety margin of minimum ambient temperatures.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public