Improvement of speech recognition by nonlinear noise reduction

The success of nonlinear noise reduction applied to a single channel recording of human voice is measured in terms of the recognition rate of a commercial speech recognition program in comparison to the optimal linear filter. The overall performance of the nonlinear method is shown to be superior. We hence demonstrate that an algorithm which has its roots in the theory of nonlinear deterministic dynamics possesses a large potential in a realistic application.Comment: see urbanowicz.org.p

Investment strategy due to the minimization of portfolio noise level by observations of coarse-grained entropy

Using a recently developed method of noise level estimation that makes use of properties of the coarse grained-entropy we have analyzed the noise level for the Dow Jones index and a few stocks from the New York Stock Exchange. We have found that the noise level ranges from 40 to 80 percent of the signal variance. The condition of a minimal noise level has been applied to construct optimal portfolios from selected shares. We show that implementation of a corresponding threshold investment strategy leads to positive returns for historical data.Comment: 6 pages, 1 figure, 1 table, Proceedings of the conference APFA4. See http://www.chaosandnoise.or

Anti-deterministic behavior of discrete systems that are less predictable than noise

We present a new type of deterministic dynamical behaviour that is less predictable than white noise. We call it anti-deterministic (AD) because time series corresponding to the dynamics of such systems do not generate deterministic lines in Recurrence Plots for small thresholds. We show that although the dynamics is chaotic in the sense of exponential divergence of nearby initial conditions and although some properties of AD data are similar to white noise, the AD dynamics is in fact less predictable than noise and hence is different from pseudo-random number generators.Comment: 6 pages, 5 figures. See http://www.chaosandnoise.or

Combustion Process in a Spark Ignition Engine: Dynamics and Noise Level Estimation

We analyse the experimental time series of internal pressure in a four cylinder spark ignition engine. In our experiment, performed for different spark advance angles, apart from usual cyclic changes of engine pressure we observed oscillations. These oscillations are with longer time scales ranging from one to several hundred engine cycles depending on engine working conditions. Basing on the pressure time dependence we have calculated the heat released per cycle. Using the time series of heat release to calculate the correlation coarse-grained entropy we estimated the noise level for internal combustion process. Our results show that for a smaller spark advance angle the system is more deterministic.Comment: 15 pages, 7 figures, submitted to CHAO

Communication: How do females with Rett syndrome perform this activity and what factors influence performance?

Background Rett syndrome is a neurodevelopmental disorder primarily caused by mutations in the X-linked methyl-Cp2G-binding protein 2 (MECP2) gene. The disorder affects approximately 1 in 9000 females and is usually associated with language, physical and intellectual impairments, each of which contributes to difficulties with communication. In Rett syndrome, eye gaze is considered a common form of communication and conventional methods, such as talking and gestures, less common. Females appear to use these forms of communication to serve a number of functions including choice making, requesting, social convention, bringing attention to themselves, and to reject, comment and answer. However, the literature is limited due to poorly described case inclusion criteria, the inclusion of cases without a diagnosis of Rett syndrome and small sample sizes. Furthermore, there is a paucity of research on the numerous barriers and facilitators to successful communication. Therefore the aim of this research was to describe the performance of communication tasks in girls and women with Rett syndrome and to investigate factors that are positively and negatively associated with performance. Methods Qualitative and quantitative methods were used to understand the communication performance of girls and women with Rett syndrome and the impairments of body function and structure, activity limitations and contextual factors that influence these. The International Classification of Functioning Disability and Health - Child and Youth Version (ICF-CY) and The Communication Matrix were used as the theoretical framework throughout the research. This thesis includes four studies of which the first employed interviews with caregivers, the second and third used caregiver questionnaire data and the final utilised video data of girls and women engaged in a communicative interaction. Data were used to describe the use of specific communication modalities such as eye gaze, gestures and speech, and communicative functions including the ability to make requests and choices. Relationships between the performance of these communication tasks and factors including MECP2 mutation type, age and level of motor abilities were investigated. Results During interviews all parents reported their daughters were able to express discomfort and pleasure, and make requests and choices using a variety of modalities including body movements and eye gaze. They also reported level of functional abilities and environmental factors influenced communication performance. Questionnaire data on speech-language abilities showed 89% (685/766) acquired speech-language abilities in the form of babble or words at some point in time. Of those who acquired babble or words, 85% (581/685) experienced a regression in these abilities. Those with a p.Arg133Cys mutation were the most likely to use one or more words, prior to (RRR=3.45; 95% CI 1.15-10.41) and after (RRR=5.99; 95% CI 2.00-17.92) speech-language regression. Australian questionnaire data (n=151) found women aged 19 years or older had the lowest scores for eye gaze. Females with better gross motor abilities had higher scores for the use of eye gaze and gestures. The use of eye gaze did not vary across mutation groups, but those with a C-terminal deletion had the highest scores for use of gestures. The video study found 82.8% (53/64) of the sample made a choice, most using eye gaze. Of those who made a choice, 50% did so within 8 seconds. Conclusions In using qualitative and quantitative methods, and the ICF-CY and The Communication Matrix as the theoretical framework, this thesis was able to provide new insight into the way in which females with Rett syndrome communicate while considering the influence of impairments of body function and structure, activity limitations and contextual factors. We found that females with Rett syndrome share communicative strengths including the use of eye gaze and the ability to make choices. Multidisciplinary assessment of communication abilities, considering the range of factors identified to impact communication, and using multiple sources of information, will likely result in a more accurate assessment of the communication abilities of girls and women with Rett syndrome. Interventions should target communicative strengths, such as the use of eye gaze, and factors shown to impact communication, including the skills of communication partners. Reporting and accounting for genetic information in future research would help improve our understanding of the relationship between MECP2 and communication abilities, which may in turn improve our knowledge of the role MECP2 plays in neurodevelopment

A stabilising role of the monetary policy in the common currency union

Celem artykułu jest określenie możliwości wykorzystania jednolitej polityki pieniężnej w kształtowaniu stabilności makroekonomicznej na obszarze wspólnej waluty. Podstawą rozważań dotyczących oddziaływania polityki pieniężnej na proces stabilizacji makroekonomicznej na obszarze wspólnej waluty są prace teoretyczne na temat polityki stabilizacji. Procesy integracji walutowej powodują jednak, że wnioski wynikające z tych prac nie mogą być w prosty sposób zastosowane do analizy sytuacji gospodarczej całego ugrupowania oraz jego poszczególnych krajów członkowskich. W unii walutowej prowadzona jest jednolita polityka pieniężna dla wszystkich krajów członkowskich, które pomimo wielu cech wspólnych, stanowią dość heterogeniczną grupę zarówno pod względem istniejących w nich uwarunkowań mikro-, jak i makroekonomicznych. Te szczególne uwarunkowania powodują, że w analizie dotyczącej stabilizacyjnego oddziaływania polityki pieniężnej w unii walutowej należy uwzględnić przede wszystkim ryzyko nieadekwatności jednolitej polityki pieniężnej, jakość krajowej polityki fiskalnej, a także zagrożenie nieadekwatności polityki nadzorczej.The aim of this article is to determine the influence of the single monetary policy on the process of macroeconomic stabilisation in the monetary union. The basis for the considerations concerning the impact of the monetary policy on the macroeconomic stabilisation process in the common currency area is theoretical works on the stabilisation policy existing in the related literature. However, the monetary integration processes are responsible for the fact that the conclusions of these works cannot be easily applied to the analysis of the economic situation in the entire currency union and in its individual member states. In the monetary union, the main central bank conducts the single monetary policy for all member states which, despite many common features, are quite a heterogeneous group at the micro- as well as the macro level. These special characteristics are the reason for which the analysis of the stabilising influence of the single monetary policy in the monetary union should include a risk of inadequacy of the single monetary policy, the quality of national fiscal policy, as well as the risk of inadequacy of supervisory policy

Noise reduction in chaotic time series by a local projection with nonlinear constraints

On the basis of a local-projective (LP) approach we develop a method of noise reduction in time series that makes use of nonlinear constraints appearing due to the deterministic character of the underlying dynamical system. The Delaunay triangulation approach is used to find the optimal nearest neighboring points in time series. The efficiency of our method is comparable to standard LP methods but our method is more robust to the input parameter estimation. The approach has been successfully applied for separating a signal from noise in the chaotic Henon and Lorenz models as well as for noisy experimental data obtained from an electronic Chua circuit. The method works properly for a mixture of additive and dynamical noise and can be used for the noise-level detection.Comment: 11 pages, 12 figures. See http://www.chaosandnoise.or