Flexible Scheduling in Multimedia Kernels: an Overview

Current Hard Real-Time (HRT) kernels have their timely behaviour guaranteed on the cost of a rather restrictive use of the available resources. This makes current HRT scheduling techniques inadequate for use in a multimedia environment where we can make a considerable profit by a better and more flexible use of the resources. We will show that we can improve the flexibility and efficiency of multimedia kernels. Therefore we introduce Real Time Transactions (RTT) with Deadline Inheritance policies for a small class of scheduling algorithms and we will evaluate these algorithms for use in a multimedia environmen

Transversal interface dynamics of a front connecting a stripe pattern to a uniform state

Interfaces in two-dimensional systems exhibit unexpected complex dynamical behaviors, the dynamics of a border connecting a stripe pattern and a uniform state is studied. Numerical simulations of a prototype isotropic model, the subcritical Swift-Hohenberg equation, show that this interface has transversal spatial periodic structures, zigzag dynamics and complex coarsening process. Close to a spatial bifurcation, an amended amplitude equation and a one-dimensional interface model allow us to characterize the dynamics exhibited by this interface.Comment: 4 pages. To be published in Europhysics Letter

Are Financial Assets Priced Locally or Globally?

We review the international finance literature to assess the extent to which international factors affect financial asset demands and prices. International asset pricing models with mean-variance investors predict that an asset's risk premium depends on its covariance with the world market portfolio and, possibly, with exchange rate changes. The existing empirical evidence shows that a country's risk premium depends on its covariance with the world market portfolio and that there is some evidence that exchange rate risk affects expected returns. However, the theoretical asset pricing literature relying on mean-variance optimizing investors fails in explaining the portfolio holdings of investors, equity flows, and the time-varying properties of correlations across countries. The home bias has the effect of increasing local influences on asset prices, while equity flows and cross-country correlations increase global influences on asset prices.

Polarimetric optical-fibre sensor for biochemical measurements

The use of an optical-fibre polarimeter as a chemical sensor is demonstrated. The compound to be detected is allowed to adsorb onto a decladded 5 cm length of the fibre. The fibre is polarization maintaining with an elliptical fibre core and a D-shaped geometry. The overall retardation stability of this fibre polarimeter is ≈ 0.5 × 2π rad m−1 K−1. With this sensor adsorption processes of proteins can be followed on-line. The resulting relative phase retardations caused by the growth of a monolayer of antibodies (αhCG, αhSA) are 0.25 × 2π. For the much smaller protein hSA, this value is 0.1 × 2

Has New York Become Less Competitive in Global Markets? Evaluating Foreign Listing Choices Over Time

We study the determinants and consequences of cross-listings on the New York and London stock exchanges from 1990 to 2005. This investigation enables us to evaluate the relative benefits of New York and London exchange listings and to assess whether these relative benefits have changed over time, perhaps as a result of the passage of the Sarbanes-Oxley Act of Congress (SOX) in 2002. We find that cross-listings have been falling on U.S. exchanges as well as on the Main Market in London. This decline in cross-listings is explained by changes in firm characteristics rather than by changes in the benefits of cross-listings. We show that, after controlling for firm characteristics, there is no deficit in cross-listing counts on U.S. exchanges related to SOX. Investigating the cross-listing premium from 1990 to 2005, we find that there is a significant premium for U.S. exchange listings every year, that the premium has not fallen significantly in recent years, that it persists even when allowing for unobservable firm characteristics, and that there is a permanent premium in event time. In contrast, there is no premium for London listings for any year. Cross-listing in the U.S. leads firms to increase their capital-raising activity at home and abroad while a London listing has no such impact. Our evidence is consistent with the theory that an exchange listing in New York has unique governance benefits for foreign firms. These benefits have not been seriously eroded by SOX and cannot be replicated through a London listing.

Why are Foreign Firms Listed in the U.S. Worth More?

At the end of 1997, the foreign companies listed in the U.S. have a Tobin's q ratio that exceeds by 16.5% the q ratio of firms from the same country that are not listed in the U.S. The valuation difference is statistically significant and largest for exchange-listed firms, where it reaches 37%. The difference persists even after controlling for a number of firm and country characteristics. We propose a theory that explains this valuation difference. We hypothesize that controlling shareholders of firms listed in the U.S. cannot extract as many private benefits from control compared to controlling shareholders of firms not listed in the U.S., but that their firms are better able to take advantage of growth opportunities. Consequently, the cross-listed firms should be those firms where the interests of the controlling shareholder are better aligned with the interests of other shareholders. The growth opportunities of cross-listed firms will be more highly valued than those of firms not listed in the U.S. both because cross-listed firms are better able to take advantage of these opportunities and because a smaller fraction of the cash flow of these firms is expropriated by controlling shareholders. We find that our theory explains the greater valuation of cross-listed firms. In particular, we find expected sales growth is valued more highly for firms listed in the U.S. and that this effect is greater for firms from countries with poorer investor rights.

Professionalization of the U.S. Defense Acquisition Workforce: Progress, Problems and Future Directions

This paper provides a discussion on the professionalization of the U.S. defense acquisition workforce. Recent legislation and its impact on education, training, and experience requirements are first discussed. Problems in professionalizing the workforce are identified, such as accurately defining the workforce, developing and accessing workforce data, and effectively recruiting and retaining the workforce. The current challenges to managing the acquisition workforce include the loss of retirement-eligible personnel, understanding the differences in workforce generations, and the depleting U.S. workforce pool with increasing competition for talent. Finally, a discussion on the future of the acquisition workforce is provided by looking at the human capital strategy and identifying generational differences in new entrants to the workforce. The paper concludes by proposing that the defense acquisition system will continue to be reformed, and the acquisition workforce will need to continue to reflect the changing knowledge, skills, and abilities needed to manage defense acquisition programs

Comparison of the bidirectional reflectance distribution function of various surfaces

Described is the development and use of a system to measure the Bidirectional Reflectance Distribution Function (BRDF) of various surfaces. The BRDF measurements are used in the analysis and design of optical measurement systems, such as laser anemometers. An argon ion laser (514 nm) is the light source. Preliminary results are presented for eight samples: two glossy black paints, two flat black paints, black glass, sand blasted aluminum, unworked aluminum, and a white paint. A BaSO4 white reflectance standard was used as the reference sample throughout the tests. The reflectance characteristics of these surfaces are compared