Search results for "SELECTION"
showing 10 items of 1940 documents
Computing Euclidean Steiner trees over segments
2020
In the classical Euclidean Steiner minimum tree (SMT) problem, we are given a set of points in the Euclidean plane and we are supposed to find the minimum length tree that connects all these points, allowing the addition of arbitrary additional points. We investigate the variant of the problem where the input is a set of line segments. We allow these segments to have length 0, i.e., they are points and hence we generalize the classical problem. Furthermore, they are allowed to intersect such that we can model polygonal input. As in the GeoSteiner approach of Juhl et al. (Math Program Comput 10(2):487–532, 2018) for the classical case, we use a two-phase approach where we construct a superse…
The Construction of Collective Memory: from Franco to Democracy
2004
Collective memory is neither spontaneous nor random, but the result of a series of selective practices. It establishes group identity and sets power relations between groups. The author considers the process of selection through a case study of the transformation of Franco’s regime in Spain into a democracy. Collective memory of the time is shown to be organized around an event (the Munich Coalition or contubernio) and around the democratic transition. The author traces two opposing notions, negationist (denying any importance to Munich) and the pro-democratic, and concludes that the memory of the transition is only the memory of those who won the civil war, who were also those who enginee…
Optimisation non-lisse pour l'estimation de composants immunitaires cellulaires dans un environnement tumoral
2021
In this PhD proposal we will investigate new regularization methods of inverse problems that provide an absolute quantification of immune cell subpopulations. The mathematical aspect of this PhD proposal is two-fold. The first goal is to enhance the underlying linear model through a more refined construction of the expression matrix. The second goal is, given this linear model, to derive the best possible estimator. These two issues can be treated in a decoupled way, which is the standard for existing methods such as Cibersort, or as a coupled optimization problem (which is known as blind deconvolution in signal processing).
Violence in the Brothers Grimm's fairy tales: a corpus-based approach
2010
The purpose of this article is to carry out a corpus-based study on the presence of violence in a selection of eight tales by the Grimm's Brothers by looking at the terms which can be said to relate to the semantic field of violence. More specifically, this study will analyse a selection of eight tales in which the frequency of the words cut, dead and blood will be studied in detail. These words have been chosen due to their possible connection to violence after carrying out a quantitative analysis of the frequency of the whole main corpus. My initial hypothesis is that the corpus-based study of those eight tales would support my intuition regarding the high percentage of violence in the Br…
Testing the assumptions of conditional handicap theory: costs and condition dependence of a sexually selected trait
2000
Conditional handicap models of sexual selection predict that sexual traits are reliable signals of male quality because they are (a) condition dependent and (b) costly to produce or maintain. In this study, my objective was to experimentally investigate whether the drumming of male Hygrolycosa rubrofasciata wolf spiders is a condition-dependent costly trait. Males court females by drumming dry leaves with their abdomen and females preferentially mate with males drumming at higher rates. I manipulated male phenotypic condition and drumming rate simultaneously by keeping males on three different food rations and either introducing or not introducing them to a female. Food ration treatment aff…
Factors Affecting Male Song Evolution in Drosophila montana
2005
D. montana (a species of the D. virilis group) has spread over the northern hemisphere, populations from different areas showing both genetic and phenotypic divergence. The males of this species produce an elaborate courtship song, which plays a major role both in species recognition and in intraspecific mate choice. The genetic architecture and physical constraints, as well as the importance of the signal for species recognition, set boundaries within which this signal can vary. Within these limits, courtship song parameters may change, depending on the males' physical condition and on the environment they inhabit. Females are likely to affect song evolution by exerting directional selecti…
Sparse model-based network inference using Gaussian graphical models
2010
We consider the problem of estimating a sparse dynamic Gaussian graphical model with L1 penalized maximum likelihood of structured precision matrix. The structure can consist of specific time dynamics, known presence or absence of links in the graphical model or equality constraints on the parameters. The model is defined on the basis of partial correlations, which results in a specific class precision matrices. A priori L1 penalized maximum likelihood estimation in this class is extremely difficult, because of the above mentioned constraints, the computational complexity of the L1 constraint on the side of the usual positive-definite constraint. The implementation is non-trivial, but we sh…
Better Access to Terminology for Crisis Communications
2016
International audience; Crisis management depends on efficient communications with professional staff and with people who are affected by the crisis. The correct interpretation of general language and technical terms is crucial to take good actions and to save valuable time. To reduce the risk of misunderstandings we need a well-established crisis management terminology. Several collections of terms have been prepared for hazard areas such as pollution, radiation, fire safety, and dangerous goods. Today such terminologies can be provided on different websites, depending on how the national crisis management is organised. This distribution and a variation of different formats and user interf…
Health-related quality of life in elderly cancer patients, elderly non-cancer patients and an elderly general population
2009
Health-related quality of life (QoL) is a major topic within the care for cancer patients (CP). Compared with the general population (GP), QoL of CP is worse in most dimensions; however, only few data comparing QoL of CP with that of other patients have been provided so far. We determined QoL with the European Organization for Research and Treatment of Cancer QLQ-C30 questionnaire in hospitalized patients aged 60 years and older: 195 CP and 130 patients treated for other medical disorders (MP). In addition, data were compared with an age- and gender-stratified German GP. Explorative statistical analyses were performed. The CP aged >or=70 years compared with those aged 60-69 years had decrea…
Paternal effects on functional gender account for cryptic dioecy in a perennial plant.
2004
7 páginas, 3 figuras, 1 tabla.