Recognizing and forecasting the sign of financial local trends using hidden Markov models

The problem of forecasting financial time series has received great attention in the past, from both Econometrics and Pattern Recognition researchers. In this context, most of the efforts were spent to represent and model the volatility of the financial indicators in long time series. In this paper a different problem is faced, the prediction of increases and decreases in short (local) financial trends. This problem, poorly considered by the researchers, needs specific models, able to capture the movement in the short time and the asymmetries between increase and decrease periods. The methodology presented in this paper explicitly considers both aspects, encoding the financial returns in binary values (representing the signs of the returns), which are subsequently modelled using two separate Hidden Markov models, one for increases and one for decreases, respectively. The approach has been tested with different experiments with the Dow Jones index and other shares of the same market of different risk, with encouraging results

Feature Level Fusion of Face and Fingerprint Biometrics

The aim of this paper is to study the fusion at feature extraction level for face and fingerprint biometrics. The proposed approach is based on the fusion of the two traits by extracting independent feature pointsets from the two modalities, and making the two pointsets compatible for concatenation. Moreover, to handle the problem of curse of dimensionality, the feature pointsets are properly reduced in dimension. Different feature reduction techniques are implemented, prior and after the feature pointsets fusion, and the results are duly recorded. The fused feature pointset for the database and the query face and fingerprint images are matched using techniques based on either the point pattern matching, or the Delaunay triangulation. Comparative experiments are conducted on chimeric and real databases, to assess the actual advantage of the fusion performed at the feature extraction level, in comparison to the matching score level.Comment: 6 pages, 7 figures, conferenc

Audio-visual foreground extraction for event characterization

This paper presents a new method able to integrate audio and visual information for scene analysis in a typical surveillance scenario, using only one camera and one monaural microphone. Visual information is analyzed by a standard visual background/foreground (BG/FG) modelling module, enhanced with a novelty detection stage, and coupled with an audio BG/FG modelling scheme. The audiovisual association is performed on-line, by exploiting the concept of synchrony. Experimental tests carrying out classification and clustering of events show all the potentialities of the proposed approach, also in comparison with the results obtained by using the single modalities

Estimating adult mortality rates in the context of the AIDS epidemic in sub-Saharan Africa: analysis of DHS sibling histories

Recent efforts to model the demographic effect of the AIDS pandemic in sub-Saharan Africa have far outnumbered empirical studies of adult mortality levels and patterns in AIDS-affected countries of the region. There is still a paucity of population-based data on adult mortality for nearly all countries in the region. Using data from recent Demographic and Health Surveys (DHS) of six countries and one in-depth DHS, this paper examines the use of sibling histories to directly estimate rates of adult mortality. The countries studied include Uganda, Zambia, Central African Republic, Côte d’Ivoire, Zimbabwe, Malawi, and Tanzania. Rates of adult male and female mortality are presented at the national level in comparison to estimates obtained from other published sources, where available, and for subnational areas where cohort and other mortality studies have been recently conducted. The results indicate surprising consistency with external data and, on the whole, underscore the expected but hitherto only sparsely documented association between residence in high HIV-prevalence areas and sharply elevated mortality risk during the relevant adult ages. The cases of Zambia and Uganda in particular provide clear evidence of very high adult mortality levels among both men and women. In general, the findings of the study demonstrate that DHS-type sibling histories represent a promising, relatively untapped source of data that will add to our understanding of adult mortality dynamics in Africa. The paper discusses some of the advantages and potential limitations of the data and derived mortality estimates

On the use of SIFT features for face authentication

Several pattern recognition and classification techniques have been applied to the biometrics domain. Among them, an interesting technique is the Scale Invariant Feature Transform (SIFT), originally devised for object recognition. Even if SIFT features have emerged as a very powerful image descriptors, their employment in face analysis context has never been systematically investigated. This paper investigates the application of the SIFT approach in the context of face authentication. In order to determine the real potential and applicability of the method, different matching schemes are proposed and tested using the BANCA database and protocol, showing promising results

Integrated region- and pixel-based approach to background modelling

In this paper a new probabilistic method for background modelling is proposed, aimed at the application in video surveillance tasks using a monitoring static camera. Recently, methods employing Time-Adaptive, Per Pixel, Mixture of Gaussians (TAPPMOG) modelling have become popular due to their intrinsic appealing properties. Nevertheless, they are not able per se to monitor global changes in the scene, because they model the background as a set of independent pixel processes. In this paper, we propose to integrate this kind of pixel-based information with higher level region-based information, that permits to manage also sudden changes of the background. These pixel- and regionbased modules are naturally and effectively embedded in a probabilistic Bayesian framework called particle filtering, that allows a multi-object tracking. Experimental comparison with a classic pixel-based approach reveals that the proposed method is really effective in recovering from situations of sudden global illumination changes of the background, as well as limited non-uniform changes of the scene illumination.

Socioeconomic inequalities in childhood mortality: the 1970s to the 1980s

The last three decades have witnessed substantial reductions in childhood mortality in most developing nations. Despite this encouraging picture, analysis of WFS and DHS survey data shows that socioeconomic disparities in survival chances have not narrowed between the 1970s and 1980s, and in some cases, have widened. Changes in mother’s education and father’s occupation contributed only modestly to secular declines in mortality. In most countries studied, no more than 20 per cent of the national trend could be accounted for by compositional improvements. The median contributions of improvements in mother’s education and father’s occupation were ten and eight per cent, respectively

Subjective expectations in the context of HIV/AIDS in Malawi

In this paper we present a newly developed interactive elicitation methodology for collecting probalistic in expectations in a developing country context with low levels of literacy and numeracy, and we evaluate the feasibility and success of this method for a wide range of outcomes in rural Malawi. We find that respondents' answers about their subjective expectations take into account basic properties of probabilities, and vary meaningfully with observable characteristics and past experience. From a substantive point of view, the elicited expectation's indicate that individuals are generally aware of differential risks. For example, individuals with lower incomes and less land rightly feel at greater risk of financial distress than people with higher socioeconomic status (SES), and people who are divorced or widowed rightly feel at greater risk of being infected with HIV than currently married individuals. Meanwhile many expectations - including the probability of being currently infected with HIV - are well-calibrated compared to actual probabilities, but mortality expectations are substantially overestimated compared to life table estimates. This overestimation maylead individuals to underestimate the benefits of adopting HIV risk-reduction strategies. The skewed distribution, of expectations about condom use also suggests that a small group of innovators are the forerunners in the adoption of condoms within marriage for HIV prevention. © 2009 Adeline Delavande & Hans-Peter Kohler