Die Starrheit der Eiflächen

Ohne Zusammenfassung     

A perceptually optimised bivariate visualisation scheme for high-dimensional fold-change data

Visualising data as diagrams using visual attributes such as colour, shape, size, and orientation is challenging. In particular, large data sets demand graphical display as an essential step in the analysis. In order to achieve comprehension often different attributes need to be displayed simultaneously. In this work a comprehensible bivariate, perceptually optimised visualisation scheme for high-dimensional data is proposed and evaluated. It can be used to show fold changes together with confidence values within a single diagram. The visualisation scheme consists of two parts: a uniform, symmetric, two-sided colour scale and a patch grid representation. Evaluation of uniformity and symmetry of the two-sided colour scale was performed in comparison to a standard RGB scale by twenty-five observers. Furthermore, the readability of the generated map was validated and compared to a bivariate heat map scheme.

     

Is there a role for statistics in artificial intelligence?

Advances in Data Analysis and Classification - The research on and application of artificial intelligence (AI) has triggered a comprehensive scientific, economic, social and political discussion....     

Features of Curing of a Diane Epoxy Oligomer Modified with Epoxyphosphazene

The results of rheokinetic, dynamic mechanical, and calorimetric investigations of the process of curing of an epoxy oligomer ED-20 blend with epoxyphosphazene by a low-molecular-weight polyamide L-20 are analyzed. It is shown that the phenomenological curing kinetics of all studied systems is characterized by the presence of two stages of the process: a second-order reaction followed by a self-retarded second-order reaction upon reaching the isothermal glass transition of the system.     

Thermal oxidation of ester-modified isotactic polypropylene

The relationship between the thermal oxidation of isotactic PP samples modified by esters miscible and immiscible with the polymer and the structure of these samples has been studied. An analysis of kinetic features of oxygen uptake, buildup of oxidation products, and changes in the mechanical properties and structural parameters of PP in the course of oxidation has shown that the effect of a modifier on the kinetics of thermal oxidation of the polymer depends on compatibility of an additive and a polymer matrix. The addition of ester that is partially miscible with PP accelerates oxidation. In the case of an immiscible ester, the effect is quite the reverse. This phenomenon is rationalized by the fact that the phase state of the system determines changes in the initial structure of the polymer matrix and, hence, manifestation of structural effects in the reaction kinetics and the participation of additives in chain reactions of cooxidation with PP.     

Modular irreducible representations of the symmetric group as linear codes

We describe a particularly easy way of evaluating the modular irreducible matrix representations of the symmetric group. It shows that Specht’s approach to the ordinary irreducible representations, along Specht polynomials, can be unified with Clausen’s approach to the modular irreducible representations using symmetrized standard bideterminants. The unified method, using symmetrized Specht polynomials, is very easy to explain, and it follows directly from Clausen’s theorem by replacing the indeterminate x_ij of the letter place algebra by x_jⁱ.Our approach is implemented in SYMMETRICA. It was used in order to obtain computational results on code theoretic properties of the p-modular irreducible representation [λ]_p corresponding to a p-regular partition λ via embedding it into representation spaces obtained from ordinary irreducible representations. The first embedding is into the permutation representation induced from the column group of a standard Young tableau of shape λ. The second embedding is the embedding of [λ]_p into the space of , the p-modular representation obtained from the ordinary irreducible representation [λ] by reducing the coefficients modulo p.We include a few tables with dimensions and minimum distances of these codes; others can be found via our home page.     

The shape of the hazard function for cancer incidence

A population-based cohort consisting of 126,141 men and 122,208 women born between 1874 and 1931 and at risk for breast or colorectal cancer after 1965 was identified by linking the Utah Population Data Base and the Utah Cancer Registry. The hazard function for cancer incidence is estimated from left truncated and right censored data based on the conditional likelihood. Four estimation procedures based on the conditional likelihood are used to estimate the age-specific hazard function from the data; these were the life-table method, a kernel method based on the Nelson Aalen estimator, a spline estimate, and a proportional hazards estimate based on splines with birth year as sole covariate.The results are consistent with an increasing hazard for both breast and colorectal cancer through age 85 or 90. After age 85 or 90, the hazard function for female breast and colorectal cancer may reach a plateua or decrease, although the hazard function for male colorectal cancer appears to continue to rise through age 105. The hazard function for both breast and colorectal cancer appears to be higher for more recent birth cohorts, with a more pronounced birth-cohort effect for breast cancer than for colorectal cancer. The age specific for colorectal cancer appears to be higher for men than for women. The shape of the hazard function for both breast and colorectal cancer appear to be consistent with a two-stage model for spontaneous carcinogenesis in which the initiation rate is constant or increasing. Inheritance of initiated cells appears to play a minor role.