The Compressible to Incompressible Limit of 1D Euler Equations: the Non Smooth Case

We prove a rigorous convergence result for the compressible to incompressible limit of weak entropy solutions to the isothermal 1D Euler equations.Comment: 16 page

On Classification with Bags, Groups and Sets

Many classification problems can be difficult to formulate directly in terms of the traditional supervised setting, where both training and test samples are individual feature vectors. There are cases in which samples are better described by sets of feature vectors, that labels are only available for sets rather than individual samples, or, if individual labels are available, that these are not independent. To better deal with such problems, several extensions of supervised learning have been proposed, where either training and/or test objects are sets of feature vectors. However, having been proposed rather independently of each other, their mutual similarities and differences have hitherto not been mapped out. In this work, we provide an overview of such learning scenarios, propose a taxonomy to illustrate the relationships between them, and discuss directions for further research in these areas

Dissimilarity-based Ensembles for Multiple Instance Learning

In multiple instance learning, objects are sets (bags) of feature vectors (instances) rather than individual feature vectors. In this paper we address the problem of how these bags can best be represented. Two standard approaches are to use (dis)similarities between bags and prototype bags, or between bags and prototype instances. The first approach results in a relatively low-dimensional representation determined by the number of training bags, while the second approach results in a relatively high-dimensional representation, determined by the total number of instances in the training set. In this paper a third, intermediate approach is proposed, which links the two approaches and combines their strengths. Our classifier is inspired by a random subspace ensemble, and considers subspaces of the dissimilarity space, defined by subsets of instances, as prototypes. We provide guidelines for using such an ensemble, and show state-of-the-art performances on a range of multiple instance learning problems.Comment: Submitted to IEEE Transactions on Neural Networks and Learning Systems, Special Issue on Learning in Non-(geo)metric Space

The seed of goal-related doubts : a longitudinal investigation of the roles of failure and expectation of success among police trainee applicants

Various theories on personal goal striving rely on the assumption that failure raises doubts about the goal. Yet, empirical evidence for an association between objective failure experiences and doubts about personal long-term goals is still missing. In a longitudinal field study, applicants for a job as a police trainee (n = 172, Mage = 25.15; 55 females and 117 males) were accompanied across three measurement times over a period of five months. We investigated the effects of failure and initial expectation of success (in the standardized selection process) on doubts regarding the superordinate goal of becoming a police officer. As hypothesized, both failure and low initial expectation of success as well as their interaction led to increased goal-related doubts over time. The findings provide first empirical evidence for the role of failure in the emergence of goal-related doubts in personal long-term goals and, therefore, the disengagement process as it is hypothesized in various theories on goal striving and life-span development

Nutritional Education and Promotion in Central America Through Dietary Guidelines Development

Malnutrition has been one of the major health problems which affects two of every ten children, under five years old, in Central American countries. During recent years, in addition to malnutrition problems, almost all Central American countries have reported an increase in the incidence of chronic illness such as diabetes, cardio-vascular diseases and some cancers. This tendency has been associated with the increase of overweight and obesity among the adult population, especially among women. Both poor nutrition and over nutrition constitute high priority health problems, which need to be addressed through comprehensive health promotion programs that includes a strong component of nutrition educaiton. The strategies and actions to promote appropriate diets and healthy lifestyles, that emanated from the last International Conference on Nutrition (FAO 1992), includes: - nutrition education and dietary guidance for the general public - training of professionals in health care, agriculture extension and related services - development of food-services guidelines - involvement of consumer groups and the food industry - ensuring food quality and safety - monitoring and evaluating national food and nutrition situations - encouraging the availability of the variety of foods needed to meet consumer demand To accomplish these recommendations many sectors need to take an active role in the promotion of healthy habits. The public sector, including health professionals can work to educate the general public about diet and health. The food industry plays an essential role by responding to consumer demand to produce and market the variety of foods needed for a healthy diet. Both the formal and non-formal education system must play a central role, incorporating nutrition into education in general, and within the context of local culture. In addition to school systems, the health and agriculture sector, public information channels, unions, youth groups and community leaders should take an active role in education and promotion of nutrition healthy lifestyles (FAO 1992). I believe that the first step, to carry out such a comprehensive nutrition promotion strategy should be the development of dietary guidelines, as the basis of information that every sector should use as they develop their own educational programs, directed to different populations, applying different educational strategies. The purpose of this document is to present a model of dietary guidelines and graphic design to promote health and nutrition in Central American Countries, as well as a proposal to implement these dietary guidelines. To develop the model of dietary guidelines, experiences from different countries, such as the United States, Mexico and Venezuela were reviewed and adapted. Graphic designs from fourteen countries were reviewed. The content of this document is presented in four sections: the first one presents a bibliographic review of dietary guidelines development in the United States and Latin American countries. The second demonstrates the adaptation and application of these concepts to the development of the Guatemalan dietary guidelines and graphic design. The third section introduces a bibliographic review of the recommendations to implement dietary guidelines in the United States, as well as my suggestion to develop and implement dietary guidelines in Central American countries. In the last section I present some ideas about the application of non-formal education strategies, to adapt the dietary guidelines at community level. This document will be translated into Spanish, and will be reviewed by a team of nutritionists, communicators and educators from the Institute of Nutrition of Central America and Panama. After that, this document will be disseminated to other Latin American countries and could be used as the basis to develop dietary guidelines in Latin American countries