A novel method for quantitatively measuring social interactions on small temporal and spatial scales on the basis of interaction geometry (reduced to the parameters interpersonal distance and relative body orientation) with the help of infrared (IR) tracking is introduced. The method is intended to be used to establish a probabilistic classifier to identify existing social situations on the basis of measuring the two parameters for pairs of persons through a series of experiments. The classifier can then be used for characterizing the social context (as an evidence for or against established social situations) of users using sensors in mobile devices in view of useful future Mobile Social Networking services. A first experiment is conducted with the method, a number of standard classifiers including a Gaussian Mixture Model are trained and evaluated and the results are discussed.

This is a Working Paper and the author(s) would welcome any comments on the present text. Citations should refer to a Working Paper of the International Monetary Fund. The views expressed are those of the author(s) and do not necessarily represent those of the Fund.

This Working Paper should not be reported as representing the views of the IMF. The views expressed in this Working Paper are those of the author(s) and do not necessarily represent those of the IMF or IMF policy. Working Papers describe research in progress by the author(s) and are published to elicit comments and to further debate. We use data on the sources of debt finance of U.S. majority-owned foreign affiliates in 53 countries over the period 1983 to 2001 to examine the role of financial market development, and exposure to host country-specific risk on the financing choices of these affiliates. We find that total balance sheets are about four times as large as the cross-border component of foreign direct investment (FDI). The extent of financial leverage through local debt is positively related to host-country corporate tax rates, exchange rate variability, local currency-denominated sales, and financial development. Factors that further the role of local debt reduce that of parent company debt, and through this substitution overall leverage increases.

We discuss a variant of density of states (DoS) techniques for lattice field theories, the so-called "functional fit approach" (FFA). The DoS FFA is based on a density of states ρ(x) which is parameterized on small intervals of the argument x of ρ(x). On these intervals restricted Monte Carlo simulations with an additional Boltzmann factor exp(λ x) allow to determine ρ(x) very precisely by obtaining its parameters from fitting the Monte Carlo data to a known function of λ .We describe the method in detail and show its applicability in four different systems, three of which have a complex action problem: The SU(3) spin model with a chemical potential, U(1) lattice gauge theory, the Z 3 spin model with chemical potential, and 2-dimensional U(1) lattice gauge theory with a topological term. In all cases we compare to reference calculations, which partly were done in a dual formulation where the complex action problem is absent. In all four cases we find a very encouraging performance of the DoS FFA.

As low-income countries obtain sovereign credit ratings in increasing numbers, this paper examines the potential effects on the composition and volume of private capital flows. Sovereign credit ratings are unlikely to overcome the informational asymmetries that impede private capital flows, and due to new international capital adequacy rules may actually raise the costs of capital for private borrowers. Nevertheless, they could help develop local and regional securities markets and assist mature private borrowers in hitherto unrated countries. Also, there may be beneficial disciplining effects on policy makers, and a growing differentiation between countries subject to an Africa-wide risk premium.Re´sume´: Dans la mesure ou`un nombre croissant de pays a`faible revenu obtiennent des cotes de cre´dit souverain, l'article analyse les effets potentiels de la composition et du volume des flux de capitaux prive´s. Les cotes de cre´dit souverain ne vont probablement pas surmonter les asyme´tries informationnelles qui entravent les flux de capitaux prive´s et, en raison des nouvelles re`gles internationales en matie`re d'ade´quation du capital, pourraient en re´alite´augmenter les couˆts du capital pour les emprunteurs prive´s. Cependant, les cotes de cre´dit souverain pourraient contribuer a`de´velopper les marche´s re´gionaux des valeurs mobilie`res et aider les emprunteurs prive´s bien solides de pays n'ayant pas, a`ce jour, une cote de cre´dit. De meˆme, sur le plan de la discipline, elles peuvent avoir des effets be´ne´fiques sur les de´cideurs et favoriser une diffe´renciation croissante entre des pays soumis a`une prime de risque applique´e a`l'Afrique dans son ensemble.

This Working Paper should not be reported as representing views of the IMF. The views expressed in this Working Paper are those of the author(s) and do not necessarily represent those of the IMF or IMF policy. Working Papers describe research in progress by the author(s) and are published to elicit comments and to further debate. Income earned by the branches and subsidiaries of multinational firms can be either reinvested in the host country or repatriated as dividends to the firms' headquarters. Despite the rapid growth of foreign direct investment in the 1990s, there has been relatively limited analysis of the dividend behavior of multinationals. We find that investors in multinationals from the two largest foreign-investing countries-the United Kingdom and the United States-require a steady flow of dividends, consistent with a view that such regular dividend payments are a mechanism through which to discipline host-country managers. In contrast, German investors, who tend to invest in riskier countries, do not appear to demand persistent dividend payments. Changes in income also influence dividends. This payout ratio from income appears, for example, to be lower for less risky countries. Finally, the evidence suggests that dividend payments do not necessarily aggravate the balance of payments position during crises.

The views expressed in this are those of the author(s) and do not necessarily represent those of the IMF or IMP policy. Working Papers describe research in progress by the author(s) and are published to elicit comments and to further debate. WP/02/47Based on U.S. data, the returns on foreign direct investment in emerging markets are shown to be substantially higher than would be suggested by official balance of payments statistics. This paper identifies the determinants of FDI profitability in 43 industrialized and developing countries. After financial leverage and the effect of tax minimizing income transfers are controlled for, host country risk and market openness are fonnd to raise affiliate retnrns on equity and returns on sales. In the context of a number of financial crises during the 1990s, income repatriations are shown to be pro-cyclical, though the effect of host country recessions is mitigated through continued spending on fixed capital and a re-direction of affiliate sales towards export markets.

We describe and evaluate our toolkit openBliSSART (open-source Blind Source Separation for Audio Recognition Tasks), which is the C++ framework and toolbox that we have successfully used in a multiplicity of research on blind audio source separation and feature extraction. To our knowledge, it provides the first open-source implementation of a widely applicable algorithmic framework based on non-negative matrix factorization (NMF), including several preprocessing, factorization, and signal reconstruction algorithms for monaural signals. Apart from blind source separation using supervised and unsupervised NMF, we show how the framework is useful for the increasingly popular audio feature extraction methods by NMF. Furthermore, we point out a numerical optimization for NMF, and show that NMF source separation in real-time on a desktop PC is feasible with our implementation. We conclude with an evaluation of our toolkit on supervised speaker separation, demonstrating how our algorithmic framework allows to tune the real-time factors to the desired perceptual quality.