Using Bad Learners to find Good Configurations

Finding the optimally performing configuration of a software system for a given setting is often challenging. Recent approaches address this challenge by learning performance models based on a sample set of configurations. However, building an accurate performance model can be very expensive (and is often infeasible in practice). The central insight of this paper is that exact performance values (e.g. the response time of a software system) are not required to rank configurations and to identify the optimal one. As shown by our experiments, models that are cheap to learn but inaccurate (with respect to the difference between actual and predicted performance) can still be used rank configurations and hence find the optimal configuration. This novel \emph{rank-based approach} allows us to significantly reduce the cost (in terms of number of measurements of sample configuration) as well as the time required to build models. We evaluate our approach with 21 scenarios based on 9 software systems and demonstrate that our approach is beneficial in 16 scenarios; for the remaining 5 scenarios, an accurate model can be built by using very few samples anyway, without the need for a rank-based approach.Comment: 11 pages, 11 figure

CITY VIEWS

[EN] The city as the architectural setting where life takes place has frequently been a subject for painters and draughtsmen. While it has also been addressed by other media - such as film, video and photography - which, with technology, have significantly increased their communicative possibilities, drawing and painting remain the ones best capable of supporting the artists¿ requirements: It is chiefly with drawing and painting that artists are able to revive the moving and initiating experience of the discovering of a great city. Through analyzing the work of a few graphic artists we will understand how drawing and painting overcome the limitations of photography and film, while technical aid opens up a new range of options and enables higher results. In the study of the following cases we shall observe the artists aim is no other than to reduce the gap between art and life.[ES] La ciudad como escenografía arquitectónica donde transcurre la vida ha sido siempre un tema recurrente en el dibujo y la pintura, y también en otros medios gráficos como el video, el cine o la fotografía. A pesar de los innegables progresos técnicos experimentados por estos últimos con el consiguiente incremento de su capacidad de comunicación, siguen siendo el dibujo y la pintura los soportes que procuran una mejor respuesta a los planteamientos de los artistas gráficos, y especialmente cuando se trata de crear un objeto cuya contemplación permita revivir la experiencia emocionante y a menudo iniciática del descubrimiento de una gran ciudad. El análisis de unos cuantos ejemplos representativos nos permitirá comprender en qué medida el dibujo y la pintura intentan superar con sus propios recursos estas limitaciones, aprovechando al mismo tiempo -en algunos casos- las ventajas que ofrecen las tecnologías. El momento cultural en que los trabajos se producen será también determinante en la concreción de cada opción. En todos los casos, una posible lectura de la evolución histórica de este tipo de obras y estrategias de aproximación, las mostraría como intentos diversos de reducir al mínimo la distancia que separa el arte de la vida.Bigas, M.; Bravo, L.; Contepomi, G. (2012). VISTAS DE LA CIUDAD. EGA. Revista de Expresión Gráfica Arquitectónica. 17(19):148-157. doi:10.4995/ega.2012.1366SWORD148157171

Views on Prophylactic Oophorectomy

Five opinions on the removal of pre-cancerous ovaries are presented in this article by Father Quinn. His own opinion astutely bridges the traditional/ liberal arguments

Christianity Views Fetal Research

The development of defense forces is always confronted with the problem of resource constraints, including national funding sources that are faced with other priority national policy options. This paper presents the Indonesian defense doctrine and views of the threats experienced in every era of regim in Indonesia. We also, will be described the history of Indonesian defense, and a description of the threats and ambitions of the new order (Orde Baru) to the order of reform (Orde Reformasi). The research method is the literature review of various library materials. In every era of leadership Indonesia always has a desire to be the best in the international region. The priority on the economy is the direction in developing the national power. Because a country that has great economic power is certainly able to develop the welfare of its people. However, the power of this economy needs to be accompanied by a defense force to protect all the economic activities of society.Keywords: Defense Budget Policy, Strategic Environmental Threat, State Ambition, Old Order, New Order, Order of Refor

Place effects on environmental views

How people respond to questions involving the environment depends partly on individual characteristics. Characteristics such as age, gender, education, and ideology constitute the well-studied social bases of environmental concern, which have been explained in terms of cohort effects or of cognitive and cultural factors related to social position. It seems likely that people\u27s environmental views depend not only on personal characteristics but also on their social and physical environments. This hypothesis has been more difficult to test, however. Using data from surveys in 19 rural U.S. counties, we apply mixed-effects modeling to investigate simple place effects with respect to locally focused environmental views. We find evidence for two kinds of place effects. Net of individual characteristics, specific place characteristics have the expected effect on related environmental views. Local changes are related to attitudes about regulation and growth. For example, respondents more often perceive rapid development as a problem, and favor environmental rules that restrict development, in rural counties with growing populations. Moreover, they favor conserving resources for the future rather than using them now to create jobs in counties that have low unemployment. After we controlled for county growth, unemployment and jobs in resource based industries, and individual social-position and ideological factors, there remains significant place-to-place variation in mean levels of environmental concern. Even with both kinds of place effects in the models, the individual level predictors of environmental concern follow patterns expected from previous research. Concern increases with education among Democrats, whereas among Republicans, the relationship is attenuated or reversed. The interaction marks reframing of environmental questions as political wedge issues, through nominally scientific counterarguments aimed at educated, ideologically receptive audiences. © 2010, by the Rural Sociological Society