A Shannon's theory of knowledge

Our so-called "Information Society", is gradually changing into a "Knowledge Society". The Shannons Theory provided a formal and mathematical framework for information. It was very fruitful for avoiding ambiguity on the concept of information. This paper proposes a transposition of this theory for knowledge. From the three axes of a formal model designed for knowledge engineering (information, sense and context), three quantitative measures are proposed to get a measure of the quantity of knowledge of a system. This notion permits to consider applications as the cognitive measure of a web site, a knowledge community (community of practice…).Knowledge, Knowledge management, Shannon's theory

Flow-of-funds analysis at the ECB – framework and applications

The financial crisis has enhanced the need for close monitoring of financial flows in the economy of the euro area and at the global level focusing, in particular, on the development of financial imbalances and financial intermediation. In this context flow-of-funds analysis appears particularly useful, as flow-of-funds data provide the most comprehensive and consistent set of macro-financial information for all sectors in the economy. This occasional paper presents different uses of flow-of-funds statistics for economic and monetary analysis in the euro area. Flow-of-funds data for the euro area have developed progressively over the past decade. The first data were published in 2001, and fully-fledged quarterly integrated economic and financial accounts by institutional sector have been published since 2007. The paper illustrates how flow-of-funds data enable portfolio shifts between money and other financial assets to be assessed and trends in bank intermediation to be monitored, in particular. Based on data (and first published estimates) on financial wealth over the period 1980-2007, the paper analyses developments in the balance sheet of households and non-financial corporations in euro area countries over the last few decades and looks at financial soundness indicators using flow-of-funds data, namely debt and debt service ratios, and measures of financial wealth. Interactions with housing investment and saving are also analysed. In addition, the paper shows how flow-of-funds data can be used for assessing financial stability. Finally, the paper presents the framework for and use of flow-of-funds projections produced in the context of the Eurosystem staff macroeconomic projection exercises, and reports the outcome of a sensitivity analysis that considers the impact of interest rate changes on the interest payments and receipts of households and non-financial corporations. JEL Classification: E44, E47, E51.Flow of funds, financial account, saving, sector balance sheet, financial projections.

Photon echoes in strongly scattering media: a diagrammatic approach

We study photon echo generation in disordered media with the help of multiple scattering theory based on diagrammatic approach and numerical simulations. We show that a strong correlation exists between the driving fields at the origin of the echo and the echo beam. Opening the way to a better understanding of non-linear wave propagation in complex materials, this work supports recent experimental results with applications to the measurement of the optical dipole lifetime $T_2$ in powders

Not Invisible: Asian Pacific Islander Juvenile Arrests in San Francisco County

This report is based on data that was originally collected by the San Francisco Juvenile Probation Department. The data reflect all juvenile arrests in the city and county of San Francisco that were referred to the Probation Department and are presented in two ways: 1) total number of arrests per year, and 2) total number of individual youths who were arrested during a given year. Many of the youths who were categorized in the race/ethnic field as "Other Asian" and "Other" can be classified into a specific race/ethnic group by examining the youth's last name. A database of common Asian Pacific Islander surnames and the race/ethnic group that coincides with that surname was developed for the purpose of this project