Reducing Ultrasonic Signal Noise by Algorithms based on Wavelet Thresholding

Traditional techniques for reducing ultrasonic signal noise are based on the optimum frequency of an acoustic wave, ultrasonic probe construction and low-noise electronic circuits. This paper describes signal processing methods for noise suppression using a wavelet transform. Computer simulations of the proposed testing algorithms are presented

Using the Correlation Function in Ultrasonic Non-destructive Testing

This paper deals with ultrasonic signal de-noising by means of correlation. It is commonly known that the cross-correlation function shows the statistical dependence between two signals. In ultrasonic inspection, the measured signal is taken as the first signal. The most important aspect of this method is the choice of the second signal. Various types of the second signals can be tried

Chaos in drive systems

The purpose of this article is to provide an elementary introduction to the subject of chaos in the electromechanical drive systems. In this article, we explore chaotic solutions of maps and continuous time systems. These solutions are also bounded like equilibrium, periodic and quasiperiodic solutions

Efficiency in Carrying Cargo to Earth Orbits: Spaceports Repositioning

Space flights are in these days not any more question of technology, but more question of costs. One way how to decrease cost of launch is change of home spaceport. Change of home spaceport for different rockets is a way to achieve more efficient launches to space. The reason is different acceleration achieved from Earth rotation. We added several mathematical calculations of missions to Low Earth Orbit and Geostationary Earth Orbit to show bonuses from Earth rotation and effect of atmospheric drag on specific rockets used these days. We discussed only already used space vessels. Namely Arianne 5, Delta 4 heavy, Proton-M, Zenit and Falcon9. For reaching GEO we discuss possibility of using Hohmman transfer, because none of aforementioned vessels is available for direct GEO entry. As possible place for launch we discussed spaceports Baikonur, Kennedy Space center, Guyana Space center and Sea Launch platform. We present results in form of additional acceleration for each spaceport, and we also project this additional acceleration in means payload increase. In conclusion we find important differences between vessel effectivity based on spaceport used for launch. Change of launch location may bring significant cost decrease for operators

Electron scattering in HCl: An improved nonlocal resonance model

We present an improved nonlocal resonance model for electron-HCl collisions. The short-range part of the model is fitted to ab initio electron-scattering eigenphase sums calculated using the Schwinger multichannel method, while the long-range part is based on the ab initio potential-energy curve of the bound anion HCl-. This model significantly improves the agreement of nonlocal resonance calculations with recent absolute experimental data on dissociative electron attachment cross sections for HCl and DCl. It also partly resolves an inconsistency in the temperature effect in dissociative electron attachment to HCl present in the literature. Finally, the present model reproduces all qualitative structures observed previously in elastic scattering and vibrational-excitation cross sections

Identification of Candidate Genes for Psychological Resilience to Develop an Additive Genetic Resilience Index: An Integrative Review

Problem: Most individuals experience at least one potentially traumatic event (PTE), such as tornado, in their lifetime. When exposed to PTEs, some individuals are more vulnerable to psychopathology, such as Posttraumatic Stress Disorder (PTSD). In contrast, other individuals are better able to cope with PTEs and maintain their psychological health. Such individuals are often described as psychologically resilient. Resilience is heritable, influenced by multiple genes including the Serotonin-Transporter-Linked Polymorphic Region (5-HTTLPR), the most studied candidate gene. Because resilience is polygenic, it is important to consider the influence of multiple genes in addition to 5-HTTLPR when studying the heritable component of resilience. Identifying additional candidate genes is the first step in constructing an Additive Genetic Resilience Index. Purpose: The purpose is to determine the polygenetic contributions of selected genes to resilience after exposure to stress and PTEs. Search: PubMed, EMBASE, PsychINFO, and CINAHL databases were searched in October 2014. The keywords included “resilience”, “serotonin transporter gene”, and “5-HTTLPR”. Inclusion criteria were: (1) human subjects approved research, (2) published in English, (3) peer-reviewed research articles, (4) both genotypes and resilience measured, and (5) 5-HTTLPR and additional gene(s) investigated. Results: Studies that examined 5-HTTLPR, additional gene(s), and resilience were selected (n = 8). Level of evidence was IV (i.e., well-designed case-control and cohort studies). Synthesis: Candidate genes for resilience in addition to 5-HTTLPR included: Catechol-O-Methyl Transferase (COMT), Monoamine Oxidase A (MAOA), Brain-Derived Neurotrophic Factor (BDNF), Dopamine Receptor D2 (DRD2) and D4 (DRD4), Corticotropin Releasing Hormone Receptor 1 (CRHR1), and Oxytocin Receptor (OXTR) genes. The variants associated with resilience were: the L allele of 5-HTTLPR, Met allele of COMT, 3.5 or greater repeaters of MAOA, Val allele of BDNF, A1 allele of DRD2, S allele of DRD4, 1 or 2 copies of CRHR1, and G allele of OXTR. A notable gap is the lack of adult samples. Practice implications: An Additive Genetic Resilience Index can be developed to examine an association between psychological resilience and multiple candidate genes. A validated genetic resilience index will help identify individuals at greater heritable risk for psychological problems after exposure to PTEs

Virtual model of CNC woodworking machine for processing chipboard material

Práce se zabývá vytvořením virtuálního modelu dřevoobráběcího CNC stroje pro zpracování deskového materiálu. Úvod do problematiky je proveden pomocí obecných trendů vývoje techniky a popisem simulovaného stroje. Dále je uveden přehled fyzikálních zákonů a teorií, ze kterých bylo vycházeno při tvorbě simulačního algoritmu. V praktické části je popsána struktura vytvořeného programu a jednotlivých používaných dílčích funkcí a podprogramů. Pro každou virtuální osu stroje jsou uvedeny číselné hodnoty parametrů, grafické výstupy ze simulace a rovnice integrované uvnitř programu. Na závěr je vytvořený program zhodnocen a jsou porovnány varianty konstrukce dle zadání. Uvedeny jsou také možná budoucí rozšíření programu, aby lépe aproximoval realitu.The thesis look into the making of a virtual model of CNC woodworking machine for processing chipboard material. An introduction to the problem is made by describing general trends in technology development and by a description of the simulated machine. It gives an overview of the physical laws and theories, which were used in the making of the simulation algorithm. The practical part describes the structure of the created program and the used individual sub-functions and sub-programs. For each virtual machine axis state numeric input parameter values, graphical outputs from the simulation and the equations integrated in the program. Finally, the program is evaluated and the design variants of the machine are compared. There are describe also possible future extensions of the program to better approximate the reality

Analiza i modeliranje dinamičkih svojstava interaktivnog pogonskog sustava

The recent drive systems are considered as interactive systems containing a range of subsystems with different physical nature. This contribution deals with the modelling of mechatronic drive systems using numerical package DYNAST. The theoretical general observations are demonstrated on particular experiments on real system.Moderni pogonski sustavi smatraju se interaktivnim sustavima koji sadržavaju podsustave različitih fizikalnih svojstava. Ovaj dokument prikazuje modeliranje mehatroničkog pogonskog sustava korištenjem numeričkog paketa DYNAST. Načelna teorijska razmatranja demonstrirana su pomoću konkretnih eksperimenata na realnom sustavu