We consider a chaotic system with a double-scroll attractor proposed by Elwakil, composing with a second-order system, which has low-dimensional multiple invariant subspaces and multi-level on-off intermittency. This type of composite system always includes a skew-product structure and some invariant subspaces, which are associated with different levels of laminar phase. In order for the level of laminar phase be adjustable, we adopt a nonlinear function with saturation characteristic to tune the range of a certain state variable so that the number and position of the laminar phase level can be arbitrarily controlled. We find that there exist many interesting statistical characteristics in this complex system, such as the probability distribution of the laminar lengths with -3/2 exponent in the power law and random jumping of the system trajectories.
Car manufacturers define proprietary protocols to be used inside their vehicular networks, which are kept an industrial secret, therefore impeding independent researchers from extracting information from these networks. This article describes a statistical and a neural network approach that allows reverse engineering proprietary controller area network (CAN)-protocols assuming they were designed using the data base CAN (DBC) file format. The proposed algorithms are tested with CAN traces taken from a real car. We show that our approaches can correctly reverse engineer CAN messages in an automated manner.
Alzheimer's Disease (AD) is the most frequent form of degenerative dementia and its early diagnosis is essential for effective treatment. Functional imaging modalities including Single Photon Emission Computed Tomography (SPECT) are often used with such an aim. However, conventional evaluation of SPECT images relies on manual reorientation and visual evaluation of tomographic slices which is time consuming, subjective and therefore prone to error. Our aim is to show an automatic Computer-Aided Diagnosis (CAD) system for improving the early detection of the AD. For this purpose, affine invariant descriptors of 3D SPECT image can be useful. The method consists of four steps: evaluation of invariant descriptors obtained using spherical harmonic analysis, statistical testing of their significance, application of regularized binary index models, and model verification via leave-one-out cross-validation scheme. The second approach is based on Support Vector Machine (SVM) classifier and visualization with use of self-organizing maps. Our approaches were tested on SPECT data from 11 adult patients with definite Alzheimer's disease and 10 adult patients with Amyotrophic Lateral Sclerosis (ALS) who were used as controls. A significant difference between SPECT spherical cuts of AD group and ALS group was both visually and numerically evaluated.
Data on divorces are gathered by the Czech Statistical Office and thus widely accessible and well known, but much less information is available about the stability of unmarried cohabitations. This paper focuses on the differences between marriage and unmarried cohabitations in terms of their stability. The authors study the impact of various factors on the stability of marriages and unmarried cohabitations taking into account the different socio -demographic indicators. To explain this phenomenon they use various theoretical approaches emphasizing different factors of partnership instability (from socializing factors to premarital cohabitation, values, education and gender, to factors based on the theory of rational choice). The analysis identified factors that operate in the same manner within both marriages and unmarried cohabitations (e.g. children in the partnership, experience with the previous partnership break-ups) as well as factors that play a different role in the stability of marriages and unmarried cohabitations (e.g. education, duration of partnership, generation). The paper is based on quantitative data from the survey ‘Life-course 2010’, which included 4010 respondents. The authors used the event history approach in their analysis which enabled them to track the dependences of the variables in time., Marta Vohlídalová, Hana Maříková., 1 graf, 1 tabulka, Poznámky na str. 14-15 (14), Biografické poznámky o autorkách článku na str. 15, Obsahuje bibliografii, and Resumé o klíčová slova anglicky na str. 3
The catologues of visual and eclipsing binaries have been analyzed by means of a mulivariate statistical method, with the purpose of putting into evidence mutual relations among the observed quantities as well as clustering properties in the mulri-dimensional space. Preliminary results of the analysis show several interesting feataures, and a physical interpretation can be attempted. Nevertheless, observational selection effects play an important role. The way back to the understanding of formation and evolutionary properties is extremely difficult, and unbiased conclusions about fundamental parameters as the initial period and mass ratio distributions cannot be obtained.