Adaptive estimation of the density matrix in quantum homodyne tomography with noisy data

In the framework of noisy quantum homodyne tomography with efficiency parameter $1/2 < \eta \leq 1$, we propose a novel estimator of a quantum state whose density matrix elements $\rho_{m,n}$ decrease like $Ce^{-B(m+n)^{r/ 2}}$, for fixed $C\geq 1$, $B>0$ and $0<r\leq 2$. On the contrary to previous works, we focus on the case where $r$, $C$ and $B$ are unknown. The procedure estimates the matrix coefficients by a projection method on the pattern functions, and then by soft-thresholding the estimated coefficients. We prove that under the $\mathbb{L}_2$ -loss our procedure is adaptive rate-optimal, in the sense that it achieves the same rate of conversgence as the best possible procedure relying on the knowledge of $(r,B,C)$. Finite sample behaviour of our adaptive procedure are explored through numerical experiments

Derivatives with respect to metrics and applications: subgradient marching algorithm

This paper introduces a subgradient descent algorithm to compute a Riemannian metric that minimizes an energy involving geodesic distances. The heart of the method is the Subgradient Marching Algorithm to compute the derivative of the geodesic distance with respect to the metric. The geodesic distance being a concave function of the metric, this algorithm computes an element of the subgradient in O(N 2 log(N)) operations on a discrete grid of N points. It performs a front propagation that computes a subgradient of a discrete geodesic distance. We show applications to landscape modeling and to traffic congestion. Both applications require the maximization of geodesic distances under convex constraints, and are solved by subgradient descent computed with our Subgradient Marching. We also show application to the inversion of travel time tomography, where the recovered metric is the local minimum of a non-convex variational problem involving geodesic distance

Adaptive Measurement Network for CS Image Reconstruction

Conventional compressive sensing (CS) reconstruction is very slow for its characteristic of solving an optimization problem. Convolu- tional neural network can realize fast processing while achieving compa- rable results. While CS image recovery with high quality not only de- pends on good reconstruction algorithms, but also good measurements. In this paper, we propose an adaptive measurement network in which measurement is obtained by learning. The new network consists of a fully-connected layer and ReconNet. The fully-connected layer which has low-dimension output acts as measurement. We train the fully-connected layer and ReconNet simultaneously and obtain adaptive measurement. Because the adaptive measurement fits dataset better, in contrast with random Gaussian measurement matrix, under the same measuremen- t rate, it can extract the information of scene more efficiently and get better reconstruction results. Experiments show that the new network outperforms the original one.Comment: 11pages,8figure

Análise Espacial da Estrutura Social da Região Metropolitana de Porto Alegre (RMPA) em 1991 e 2000

This paper discusses the spatial distribution of social structures in the Metropolitan Area of Porto Alegre in 1991 and 2000 (census years), using spatial statistical techniques with a geographic information system (GIS). These structures represent a social hierarchy of the metropolitan space from across the combination of labour variables. For this goal, I use a measure of spatial dispersion: the standard deviational ellipse which does show compactness and orientation of the distribution. The paper concludes with comments regarding the patterns and trends of the distributions

Os principais parques científicos e tecnológicos gaúchos: estrutura e características

In recent years, the development of science and/or technology parks has been one of the most used tools, even if it is controversial, of innovation policy in the world. This kind of experience can promote some fundamental elements for the innovation processes: the dynamics of learning and interaction and the use of local resources. In this context, this article aims to study the three main science and technology parks in the State of Rio Grande do Sul (Brazil) — Tecnopuc, Tecnosinos e Valetec —, looking at the parks’ firms. So, we analyse firms’ aspects such as areas of expertise, activities of cooperation for innovation, and the use of external financial resources. The results indicate the relative success of these parks in fostering innovation in the territory of Rio Grande do Sul

Os principais parques científicos e tecnológicos gaúchos: estrutura e características

In recent years, the development of science and/or technology parks has been one of the most used tools, even if it is controversial, of innovation policy in the world. This kind of experience can promote some fundamental elements for the innovation processes: the dynamics of learning and interaction and the use of local resources. In this context, this article aims to study the three main science and technology parks in the State of Rio Grande do Sul (Brazil) — Tecnopuc, Tecnosinos e Valetec —, looking at the parks’ firms. So, we analyse firms’ aspects such as areas of expertise, activities of cooperation for innovation, and the use of external financial resources. The results indicate the relative success of these parks in fostering innovation in the territory of Rio Grande do Sul

Análise espacial da centralidade e da dispersão da riqueza gaúcha de 1970 a 2000: notas preliminares

Developments in spatial methodsconcerned with location, spatial interaction, spatial structure and spatial processesare creating new possibilities for studies of the properties of socioeconomic systems. In this paper, we use spatial statistical techniques with a geographic information system (GIS) for describing the spatial distribution of economic data, such as the mean center, standard distance and standard deviational ellipse. Analyzing the reality of the State of Rio Grande do Sul (Brasil), we compare the distribution of GDP, monthly income and "per capita" income observed in the period 1970-2000 (census years). The paper concludeswith some brief reflections on the patterns and trends of these distributions

O papel das Instituições de Ensino Superior para o desenvolvimento territorial: Análise da comunidade de Pós-Graduação do Rio Grande do Sul e o caso das cidades de Pelotas e Rio Grande

Nowadays, the process of innovation has become an important agent to social and economic development of regions and countries. Thus, within the context of the “heterodox paradigm of economic geography”, the region-specific capacities are fundamental for such activities of development, which one has been more and more appraised: the knowledge from the higher education institutions (HEIs). This article analyses the role of HEIs in general and the situation in the State of Rio Grande do Sul (Brazil) in particular, in the period of 2000 through 2010, by means of the postgraduate structure. The paper ends with some considerations about a regional agenda of research to the municipalities of Pelotas and Rio Grande in the sense of their territorial development within the heterodox perspective. The results highlight the strength of postgraduate structure of the region and, consequently, higher education in general, also stressing the State potentialities for scientific, technological and of innovative progress

Os principais parques científicos e tecnológicos gaúchos: estrutura e características

Nos últimos anos, o desenvolvimento de parques científicos e/ou tecnológicos tem-se constituído em um dos instrumentos mais utilizados, ainda que controversos, de política de inovação no mundo. Nesse sentido, esse tipo de experiência pode fomentar alguns elementos fundamentais para os processos de inovação: as dinâmicas de aprendizagem e de interação e o aproveitamento dos recursos localizados em cada território. Nesse contexto, o artigo tem por objetivo estudar os três principais parques científicos e tecnológicos do Rio Grande do Sul — Tecnopuc, Tecnosinos e Valetec — a partir das empresas localizadas nesses locais. Assim, são analisados aspectos dessas firmas, como áreas de atuação, atividades de cooperação para inovar e uso de recursos financeiros externos. Os resultados apontam um relativo sucesso desses parques no âmbito da promoção da inovação, no território gaúcho.Palavras-chave: parques científicos e/ou tecnológicos; inovação; Rio Grande do Sul  Título em inglêsThe main science and technology parks in the State of Rio Grande do Sul: structure and characteristicsAbstractIn recent years, the development of science and/or technology parks has been one of the most used tools, even if it is controversial, of innovation policy in the world. This kind of experience can promote some fundamental elements for the innovation processes: the dynamics of learning and interaction and the use of local resources. In this context, this article aims to study the three main science and technology parks in the State of Rio Grande do Sul (Brazil) — Tecnopuc, Tecnosinos e Valetec —, looking at the parks’ firms. So, we analyse firms’ aspects such as areas of expertise, activities of cooperation for innovation, and the use of external financial resources. The results indicate the relative success of these parks in fostering innovation in the territory of Rio Grande do Sul.Keywords: science and/or technology parks; innovation; Rio Grande do SulClassificação JEL: O31Artigo recebido em 31 mar. 201

As inovações nos territórios e o papel das universidades: notas preliminares para o desenvolvimento territorial no Estado do Rio Grande do Sul

Through the prism of the economic geography this paper examines some of the theoretical bases of studies about science, technology and technological innovations for the economic and social development of regions and countries. It highlights the roles of higher education institutions – teaching, research and community service – for the territorial and technological development. Focusing the State of Rio Grande do Sul (Brazil), we use a piece of information of the Technological Innovation Survey – Pintec (IBGE/Finep/MCT) referring to the relations between higher education institutions and firms in innovation activities observed in the period 1998-2005, more specifically, sources of information and co-operation. Finally, the paper concludes by relating these findings about universities, firms, territories and its relationships, to ongoing debates around development and innovation