Paris Dauphine University

About: Paris Dauphine University is a education organization based out in Paris, France. It is known for research contribution in the topics: Population & Approximation algorithm. The organization has 1766 authors who have published 6909 publications receiving 162747 citations. The organization is also known as: Paris Dauphine & Dauphine.

Structured Sparsity Models for Reverberant Speech Separation

Abstract: We tackle the speech separation problem through modeling the acoustics of the reverberant chambers. Our approach exploits structured sparsity models to perform speech recovery and room acoustic modeling from recordings of concurrent unknown sources. The speakers are assumed to lie on a two-dimensional plane and the multipath channel is characterized using the image model. We propose an algorithm for room geometry estimation relying on localization of the early images of the speakers by sparse approximation of the spatial spectrum of the virtual sources in a free-space model. The images are then clustered exploiting the low-rank structure of the spectro-temporal components belonging to each source. This enables us to identify the early support of the room impulse response function and its unique map to the room geometry. To further tackle the ambiguity of the reflection ratios, we propose a novel formulation of the reverberation model and estimate the absorption coefficients through a convex optimization exploiting joint sparsity model formulated upon spatio-spectral sparsity of concurrent speech representation. The acoustic parameters are then incorporated for separating individual speech signals through either structured sparse recovery or inverse filtering the acoustic channels. The experiments conducted on real data recordings of spatially stationary sources demonstrate the effectiveness of the proposed approach for speech separation and recognition.

Solar photovoltaic energy policy and globalization: a multiperspective approach with case studies of Germany, Japan, and China

Abstract: Solar photovoltaic (PV) systems have experienced strong market growth over the last decade. Since the mid-2000s, the increase in demand in line with policy supports in Europe has attracted the Chinese players into the PV manufacturing market. Chinese production soared in a short time and managed to quickly reduce the cost thanks to large-scale supply with mass-produced products. Faced with the global economic crisis, the European countries began reducing their policy supports that caused a decrease in the demand for PV installations. Despite such a market situation, Chinese PV manufacturers have continued to produce large quantities of solar PV products and thereby aggravated the global PV industry situation with a global supply–demand imbalance. China's rapid market expansion without domestic market development has brought unexpected results with an oversupply of PV materials and equipment in a global market and destabilized the PV market. It influenced the PV policy mechanisms of other countries. Many PV firms in the world have since gone into bankruptcy. China and Europe lately went through a trade dispute over the Chinese solar panel imports (dumping suspicion). In this context, this study aims to identify the PV policy mechanisms based on a multiperspective approach in Germany, Japan, and China. A systematic logical framework is proposed and then used to explain each country's PV policy strategy and results. Moreover, PV globalization impacts and interactions among them are studied using the international trade theory. At the end, this research also attempts to seek optimal strategies to improve the global PV mechanisms. Copyright © 2014 John Wiley & Sons, Ltd.

Health expenditure, longevity and growth

Abstract: This paper offers an integrated view of the relationships between health spending, medical innovation, health status, growth and welfare. Health spending triggers technological progress, which is a potential source of better outcomes in terms of longevity and quality of life, a direct source of growth for the bio-tech industries and an indirect source of growth through improved of human capital. The latter contributes to GDP per capita through two main channels: higher participation of the population in the labour force and higher labour productivity levels. In turn, income growth induces an increase in health expenditure, as richer countries tend to spend a higher share of their income on health. To analyse these interactions, the paper first focuses on demographic facts, disentangling the role of longevity and carrying out some 'thought experiments' on the indexation of active life on longevity. It then analyses the links between health care expenditures, technology and health status from a micro-level perspective. We investigate empirically the relation between GDP growth and health expenditures and develop a projection method to assess the size of total aggregate expenditures that could be channeled to the health sector up to 2050 for the US, Europe and Japan. We finally assess the potential impact of these health expenditures and better health status on potential growth and productivity.

A multi-national study of attitudes about mobile phone use in social settings

Abstract: Mobile phones have taken on the role of providing truly portable and individual communications and computing. Unlike many devices, however, mobile phones can be used anywhere and anytime. Consequently, they are used in social situations such as restaurants and theatres where co-located people can be bothered by their use. How people perceive the impact of mobile phones in these situations may vary by user factors such as age, gender and work status, and by the country in which the user is located. This paper presents the results of a multi-national study of attitudes about mobile phone use in social situations.