Orthogonal Transform Multiplexing with Memoryless Nonlinearity: a Possible Alternative to Traditional Coded-Modulation Schemes

In this paper, we propose a novel joint coding-modulation technique based on serial concatenation of orthogonal linear transform, such as discrete Fourier transform (DFT) or Walsh-Hadamard transform (WHT), with memoryless nonlinearity. We demonstrate that such a simple signal construction may exhibit properties of a random code ensemble, as a result approaching channel capacity. Our computer simulations confirm that if the decoder relies on a modified approximate message passing algorithm, the proposed modulation technique exhibits performance on par with state-of-the-art coded modulation schemes that use capacity-approaching component codes. The proposed modulation scheme could be used directly or as a pre-coder for a conventional orthogonal frequency division multiplexing (OFDM) transmitter, resulting in a system possessing all benefits of OFDM along with reduced peak-to-average power ratio (PAPR)

Computation of multiple functional integrals in quantum physics

AbstractThe new method of computation of multiple functional integrals of quantum physics is elaborated. The method is based on the numerical integration over complete separable metric spaces via approximations exact on a class of polynomial functionals of given degree. New approximation formulas for the functional integrals with respect to Gaussian measure are constructed. The convergence of approximations to an exact value of integral is proved, the estimate of the remainder is obtained. In the particular case of conditional Wiener measure the approximation formulas with the weight are derived. The method is applied to the study of the multidimensional Calogero model and to computation of the binding of nucleons in the nucleus of tritium

Relativistic spherical plasma waves

Tightly focused laser pulses as they diverge or converge in underdense plasma can generate wake waves, having local structures that are spherical waves. Here we report on theoretical study of relativistic spherical wake waves and their properties, including wave breaking. These waves may be suitable as particle injectors or as flying mirrors that both reflect and focus radiation, enabling unique X-ray sources and nonlinear QED phenomena.Comment: 6 pages; 4 figure

Теоретичні основи створення системи автоматизованого управління ризиком для об’єктів машинобудування підвищеної небезпеки

В монографії викладено основні поняття управління ризиками при екс- плуатації технічних систем та моделі для побудування автоматизованої системи управління ризиками, на основі реалізації комплексу узгоджених заходів щодо забезпечення прийнятного рівня ризику, а також оцінки стійкості деградаційних процесів в елементах об’єктів машинобудування підвищеної небезпеки. Монографія може бути корисною широкому колу науковців та фахівців, які працюють з ТС і діяльність яких пов’язана з визначенням їх предруйнівного стану та прийняттям рішення про продовження, або припинення експлуатації об’єктів машинобудування підвищеної небезпеки

Random data Cauchy theory for supercritical wave equations II : A global existence result

We prove that the subquartic wave equation on the three dimensional ball $\Theta$, with Dirichlet boundary conditions admits global strong solutions for a large set of random supercritical initial data in $\cap_{s<1/2} H^s(\Theta)$. We obtain this result as a consequence of a general random data Cauchy theory for supercritical wave equations developed in our previous work \cite{BT2} and invariant measure considerations which allow us to obtain also precise large time dynamical informations on our solutions

Stability of boron-doped graphene/copper interface: DFT, XPS and OSEE studies

Two different types of boron-doped graphene/copper interfaces synthesized using two different flow rates of Ar through the bubbler containing the boron source were studied. X-ray photoelectron spectra (XPS) and optically stimulated electron emission (OSEE) measurements have demonstrated that boron-doped graphene coating provides a high corrosion resistivity of Cu-substrate with the light traces of the oxidation of carbon cover. The density functional theory calculations suggest that for the case of substitutional (graphitic) boron-defect only the oxidation near boron impurity is energetically favorable and creation of the vacancies that can induce the oxidation of copper substrate is energetically unfavorable. In the case of non-graphitic boron defects oxidation of the area, a nearby impurity is metastable that not only prevent oxidation but makes boron-doped graphene. Modeling of oxygen reduction reaction demonstrates high catalytic performance of these materials.Comment: 15 pages, 8 figures, to appear in Appl. Surf. Sc