1,026 research outputs found
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
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
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
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
Development of a model-based approach to the characterization and diagnosis of type 1 von Willebrand disease
Von Willebrand disease (VWD) is the most common inherithed bleeding disorder and it is caused by a deficiencies of von Willebrand factor (VWF), which is a glycoprotein fundamental in the coagulation process. Type 1 is the most common VWD variant; through the clinical data and a pharmacokinetic model, an algorithmic approach supporting the diagnosis of type 1 VWD is proposed.ope
ReDreaming Dharawal: A transcultural and multi-disciplined approach to the Aboriginal art and landscapes of southern Sydney
This study addresses post-contact Aboriginal art practices of the southern Sydney region; traditional lands of the Dharawal-speaking peoples. Given that a conventional Western art history has found the pluralistic nature of such work problematic, this study seeks to understand how it might be valued and understood in a wider art-world context.
Through extensive field work which included the first survey and analysis of the large body of public art produced in association with Aboriginal people since the Bicentennial, this thesis finds that engagement with non-Aboriginal Australians is an important tactic of Aboriginal people in achieving agency in the modern world; and that, in contrast to assumptions still made about Aboriginal artists working in urban areas, re-establishing and reaffirming relationships with Country remains a core concern.
I argue that a multi-disciplined methodology that employs ideas from anthropology, archaeology and human geography offers the best means of comprehending the sensitive, transcultural nature of the art practices and art histories of Dharawal country
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