Derivation of Universal Curves for Nonlinear Soil Consolidation with Potential Constitutive Dependences

Nonlinear consolidation scenarios, based on potential type constitutive dependences—like those proposed by Juárez-Badillo—and eliminating the more restrictive hypothesis of 1+e and dz constant, were characterized by the nondimensionalization process of the governing equations, providing the independent dimensionless groups that rule the main unknowns of interest. From these, universal curves have been depicted for both the characteristic time and the average degree of consolidation. The solutions were verified by numerical simulations and successfully compared in a case study, showing the simplicity of use of the curves and the high reliability of the solutions they provide.

ON OPTIMAL STRATEGIES FOR UTILITY MAXIMIZERS IN THE ARBITRAGE PRICING MODEL

We consider a popular model of microeconomics with countably many assets: the Arbitrage Pricing Model. We study the problem of optimal investment under an expected utility criterion and look for conditions ensuring the existence of optimal strategies. Previous results required a certain restrictive hypothesis on the tails of asset return distributions. Using a different method, we manage to remove this hypothesis, at the price of stronger assumptions on the moments of asset returns.

On Some Assumptions of the Null Hypothesis Statistical Testing

Bayesian and classical statistical approaches are based on different types of logical principles. In order to avoid mistaken inferences and misguided interpretations, the practitioner must respect the inference rules embedded into each statistical method. Ignoring these principles leads to the paradoxical conclusions that the hypothesis [Formula: see text] could be less supported by the data than a more restrictive hypothesis such as [Formula: see text], where [Formula: see text] and [Formula: see text] are two population means. This article intends to discuss and explicit some important assumptions inherent to classical statistical models and null statistical hypotheses. Furthermore, the definition of the p-value and its limitations are analyzed. An alternative measure of evidence, the s-value, is discussed. This article presents the steps to compute s-values and, in order to illustrate the methods, some standard examples are analyzed and compared with p-values. The examples denunciate that p-values, as opposed to s-values, fail to hold some logical relations.

Especificaciones y consideraciones muestrales en la estimación de la demanda de un espacio natural singular: Las Illas Cíes en Galicia.

In this paper, we present estimates of several specifications of demand for a singular natural area using data from surveys on visitors and non-visitors. The estimates take into account the problems of functional form, measurement of the cost and of the demand, choosing sampling scheme, and handling the sample. Considering these alternatives allows us to select a specification of demand under improved conditions and frees us from initial restrictive hypothesis. The results in terms of prediction of demand and consumer surplus estimates are quite dissimilar, stressing the importance of comparing various specifications that encompass a range of possible options.

DESIGN, TESTING AND VALIDATION OF A COMPOSITE BOX UNDER COMBINED LOADING UP TO COLLAPSE

This paper presents part of the activities performed by Politecnico di Milano within the European research project COCOMAT, consisting of the design, testing and validation of a closed box structure made up of CFRP stringer-stiffened curved panels. The design phase is carried out using ABAQUS/Explicit with the purpose of obtaining a structure with a ratio between the collapse and the buckling load that is greater than 3 under axial compression and greater than 2 under torque. The box is manufactured by Agusta/Westland and tested at Politecnico di Milano. The first test results are used to validate the FE model, removing some restrictive hypothesis formulated during the design process. Finally, a comparison between the results under combined axial compression and torque loads obtained in the collapse test and in the FE analysis reproducing the collapse is shown. A good correlation is obtained, both in the buckling and postbuckling behavior and in the collapse modality, demonstrating the capability of the dynamic explicit analyses to capture the highly nonlinear response of the aeronautical panels. The results also show the possibility of CFRP structures working deeply in the postbuckling region if properly designed and, consequently, the possibility of a weight reduction of aerospace structures thanks to the possibility of moving up the ultimate load toward the collapse load without any loss in the structural safety.

A non-coprime Hall-Higman reduction theorem

In a well-known paper, Hall and Higman proved the reduction theorem on a coprime order operator group acting on a finite group. This theorem plays an important role in local analysis of finite group theory. In this paper, we generalize the Hall-Higman reduction theorem by dropping the restrictive hypothesis (|G|, |H|) = 1 and determine the detailed structure of G completely.

Real inequalities with applications to function theory

Suppose that f(x) is non-negative for x ≥ 0 and letIn a recent paper (4) inequalities were proved relating fn(x) with the nth derivative f(n)(x) of f(x). However, the two main results, Theorems 3 and 4, were proved only for n = 1 and 2. In the first part of this paper we shall prove the corresponding results for all positive integral n under a slightly less restrictive hypothesis (Theorem 3). We shall then give an application showing that from the hypothesis f(x) ≤ μ(x) for all x it is sometimes possible to deduce f(n)(x) = O{μ(n)(x)} for a set of values x depending only on μ(x).