A Taxonomy of Technical Animation

The age in which we are living nowadays is characterized by rapid innovation in the development of information and communication technologies (ICT). This innovation has a significant influence on the education process. This article deals with computer animation in technical education. Our aim is to show the taxonomy of education animation. The paper includes practical examples of animation

UML-oriented Risk Analysis in Manufacturing Systems

Whenever we want to avoid failures or hazardous events in today’s complex technological systems, it is advisable to carry out appropriate risk management. One of the most important aspects of risk management is the risk analysis process. The aim of this paper is to show a new risk analysis method based on the Unified Modelling Language (UML), which is successfully used in software engineering for describing the problem domain. The paper also includes a small practical example. It also shows a new risk analysis method based on an example of an unreeling process in cable manufacturing

Electronic Education

The age in which we are living nowadays is characterized by rapid innovation in the development of information and communication technologies (ICT). This innovation has a significant influence on the education process. This paper deals with e-learning

Stabilization of persistent organic pollutants (POP) in flue gases in a biological waste incinerating facility

ArticleThe article focuses on a technology of flue gases stabilization in biological and hospital waste incinerating facility. Hazardous particles and compounds formed in flue gas during the process of thermal waste degradation need to be stabilized according to an enacted legislation. The aim of the research is to examine technological process of polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDD/F) elimination in flue gas. PCDD/F is group of persistent organic pollutants which are resistant to environmental degradation and are highly toxic for the environment in very small amounts. Experiments were performed in semi operation hospital waste incinerating plant with heating power 1.5 MW and capacity 250 kg h - 1 of incinerating material. It was observed that formation of PCDD/F exponentially grows with increasing concentration of chlorides in the flue gas, but formation varies based on type of congener. The highest concentration was measured for HxDF, 17,522 pg Nm - 3 and HpDF, 16,334 pg Nm - 3 at chloride concentration of 867 mg Nm - 3 . However, concentration of PCDD congeners didn ́t exceeded 4,000 pg Nm - 3 for the same level of chlorides in flue gas. Two types of activated carbon Chezacarb and NORIT were tested for capability to stabilize PCDD/F in flue gas. Results show that refining effect for both sorbent are very similar. It was observed that 0.1 g of activated carbon should be applied per 1 Nm 3 of flue gas in regard to reduce 3 – 4 ng Nm - 3 PCDD/F under required emission limit

Practical Implementation of Animation for Students of Pedagogical Studies at MIAS CTU in Prague

This paper shows computer animation as a teaching and learning instrument in technical education. Our aim is to show good practice in creating computer animations. The paper includes an example, which can serve as a practical guide for teachers of technical subjects

Mechanical Splices for Seismic Retrofitting of Concrete Structures

As an alternative to lap splicing, mechanical splices can be used for retrofit purposes. They are generally most economical than traditional lap splices when available spacing or length makes laps difficult to utilize. Mechanical splices are frequently used in new construction. However, their use is limited and not practical for use in retrofitted structures. However, if the bars to be joined do not need to be threaded in order to be connected with a special mechanical splice, such mechanical splices can be useful. It is presented a proposal of using two types of mechanical splices for retrofit purposes. Cycle Tension and cycle tension-compression tests are presented and discussed. It was found that mechanical splices are suitable and have acceptable response under seismic loads

Phase-lags in large scale brain synchronization : Methodological considerations and in-silico analysis

Architecture of phase relationships among neural oscillations is central for their functional significance but has remained theoretically poorly understood. We use phenomenological model of delay-coupled oscillators with increasing degree of topological complexity to identify underlying principles by which the spatio-temporal structure of the brain governs the phase lags between oscillatory activity at distant regions. Phase relations and their regions of stability are derived and numerically confirmed for two oscillators and for networks with randomly distributed or clustered bimodal delays, as a first approximation for the brain structural connectivity. Besides in-phase, clustered delays can induce anti-phase synchronization for certain frequencies, while the sign of the lags is determined by the natural frequencies and by the inhomogeneous network interactions. For in-phase synchronization faster oscillators always phase lead, while stronger connected nodes lag behind the weaker during frequency depression, which consistently arises for in-silico results. If nodes are in antiphase regime, then a distance Pi is added to the in-phase trends. The statistics of the phases is calculated from the phase locking values (PLV), as in many empirical studies, and we scrutinize the method's impact. The choice of surrogates do not affects the mean of the observed phase lags, but higher significance levels that are generated by some surrogates, cause decreased variance and might fail to detect the generally weaker coherence of the interhemispheric links. These links are also affected by the non-stationary and intermittent synchronization, which causes multimodal phase lags that can be misleading if averaged. Taken together, the results describe quantitatively the impact of the spatio-temporal connectivity of the brain to the synchronization patterns between brain regions, and to uncover mechanisms through which the spatio-temporal structure of the brain renders phases to be distributed around 0 and Pi.Peer reviewe

Differences in MEG and EEG power-law scaling explained by a coupling between spatial coherence and frequency: a simulation study

International audienceElectrophysiological signals (electroencephalography, EEG, and magnetoencephalography , MEG), as many natural processes, exhibit scale-invariance properties resulting in a power-law (1/f) spectrum. Interestingly, EEG and MEG differ in their slopes, which could be explained by several mechanisms, including non-resistive properties of tissues. Our goal in the present study is to estimate the impact of space/frequency structure of source signals as a putative mechanism to explain spectral scaling properties of neuroimaging signals. We performed simulations based on the summed contribution of cortical patches with different sizes (ranging from 0.4 to 104.2 cm 2). Small patches were attributed signals of high frequencies, whereas large patches were associated with signals of low frequencies, on a logarithmic scale. The tested parameters included i) the space/frequency structure (range of patch sizes and frequencies) and ii) the amplitude factor c parametrizing the spatial scale ratios. We found that the space/frequency structure may cause differences between EEG and MEG scale-free spectra that are compatible with real data findings reported in previous studies. We also found that below a certain spatial scale, there were no more differences between EEG and MEG, suggesting a limit for the resolution of both methods. Our work provides an explanation of experimental findings. This does not rule out other mechanisms for differences between EEG and MEG, but suggests an important role of spatio-temporal structure of neural dynamics. This can help the analysis and interpretation of power-law measures in EEG and MEG, and we believe our results can also impact computational modeling of brain dynamics, where different local connectivity structures could be used at different frequencies

Spherical harmonic decomposition applied to spatial-temporal analysis of human high-density EEG

We demonstrate an application of spherical harmonic decomposition to analysis of the human electroencephalogram (EEG). We implement two methods and discuss issues specific to analysis of hemispherical, irregularly sampled data. Performance of the methods and spatial sampling requirements are quantified using simulated data. The analysis is applied to experimental EEG data, confirming earlier reports of an approximate frequency-wavenumber relationship in some bands.Comment: 12 pages, 8 figures, submitted to Phys. Rev. E, uses APS RevTeX style

On the sample size dependence of the critical current density in MgB2_2 superconductors

Sample size dependent critical current density has been observed in magnesium diboride superconductors. At high fields, larger samples provide higher critical current densities, while at low fields, larger samples give rise to lower critical current densities. The explanation for this surprising result is proposed in this study based on the electric field generated in the superconductors. The dependence of the current density on the sample size has been derived as a power law $j\propto R^{1/n}$ ($n$ is the $n$ factor characterizing $E-j$ curve $E=E_c(j/j_c)^n$). This dependence provides one with a new method to derive the $n$ factor and can also be used to determine the dependence of the activation energy on the current density.Comment: Revtex, 4 pages, 5 figure