Stable splittings, spaces of representations and almost commuting elements in Lie groups

In this paper the space of almost commuting elements in a Lie group is studied through a homotopical point of view. In particular a stable splitting after one suspension is derived for these spaces and their quotients under conjugation. A complete description for the stable factors appearing in this splitting is provided for compact connected Lie groups of rank one.By using symmetric products, the colimits \Rep(\Z^n, SU), \Rep(\Z^n,U) and \Rep(\Z^n, Sp) are explicitly described as finite products of Eilenberg-MacLane spaces.Comment: 37 Pages. To appear in Math. Proc. Camb. Phil. So

Role of Physicians in Addressing Food Insecurity in Vermont Seniors

Introduction: This study investigated Vermont physicians’ awareness of - and engagement in – addressing food insecurity experienced by their elderly patients. This information is needed to better understand the role physicians play in solving this problem and to know how education and access to services could ensure that the needs of elders are met in a culturally sensitive manner. Many elders must choose between paying bills, buying medication or buying food. Some elders are unaware that they qualify for food assistance, or would feel stigmatized using it. Nationally, 56% of physicians reported that they were not knowledgeable about food insecurity. Food insecurity can be screened for by using Hunger Free Vermont’s Two Question Screen. Screening, followed by a multidisciplinary team approach with contributions from dietitians, geriatricians, social workers and psychologists may be the most effective way of assessing at-risk patients.https://scholarworks.uvm.edu/comphp_gallery/1214/thumbnail.jp

Distributed Computations with Layered Resolution

Modern computationally-heavy applications are often time-sensitive, demanding distributed strategies to accelerate them. On the other hand, distributed computing suffers from the bottleneck of slow workers in practice. Distributed coded computing is an attractive solution that adds redundancy such that a subset of distributed computations suffices to obtain the final result. However, the final result is still either obtained within a desired time or not, and for the latter, the resources that are spent are wasted. In this paper, we introduce the novel concept of layered-resolution distributed coded computations such that lower resolutions of the final result are obtained from collective results of the workers -- at an earlier stage than the final result. This innovation makes it possible to have more effective deadline-based systems, since even if a computational job is terminated because of timing, an approximated version of the final result can be released. Based on our theoretical and empirical results, the average execution delay for the first resolution is notably smaller than the one for the final resolution. Moreover, the probability of meeting a deadline is one for the first resolution in a setting where the final resolution exceeds the deadline almost all the time, reducing the success rate of the systems with no layering

Stream Distributed Coded Computing

The emerging large-scale and data-hungry algorithms require the computations to be delegated from a central server to several worker nodes. One major challenge in the distributed computations is to tackle delays and failures caused by the stragglers. To address this challenge, introducing efficient amount of redundant computations via distributed coded computation has received significant attention. Recent approaches in this area have mainly focused on introducing minimum computational redundancies to tolerate certain number of stragglers. To the best of our knowledge, the current literature lacks a unified end-to-end design in a heterogeneous setting where the workers can vary in their computation and communication capabilities. The contribution of this paper is to devise a novel framework for joint scheduling-coding, in a setting where the workers and the arrival of stream computational jobs are based on stochastic models. In our initial joint scheme, we propose a systematic framework that illustrates how to select a set of workers and how to split the computational load among the selected workers based on their differences in order to minimize the average in-order job execution delay. Through simulations, we demonstrate that the performance of our framework is dramatically better than the performance of naive method that splits the computational load uniformly among the workers, and it is close to the ideal performance

Condensadores sociales

El documento es parte del libro Cien Cafés : 100 textos nuevos, 100 autores, 100 notas de café de las ciudades, 100 datos sobre la ciudad futura.En una época esencialmente pesimista acerca de las consecuencias que la huella ecológica del progreso dejará en la habitabilidad del mundo, es bueno preguntarse que hacer para seguir teniendo paisajes culturales donde vivir, para no resignarse a lo dado como definitivo. Nuestra esperanza proyectual está fundada precisamente en la posibilidad de transformar la realidad, aún desde los peores escenarios. Y a otro balance sociedad naturaleza.Fil: Cohen, Alejandro. Universidad Nacional de Córdoba. Facultad de Arquitectura, Urbanismo y Diseño. Cátedra Arquitectura V B; Argentina.Estudios Urbanos (Planeamiento y Desarrollo