Ergodicity of certain cocycles over certain interval exchanges

We show that for odd-valued piecewise-constant skew products over a certain two parameter family of interval exchanges, the skew product is ergodic for a full-measure choice of parameters

Организация и ведение поисково и аварийно-спасательных работ на водоемах

Проведение поисковых и аварийно-спасательных работ на воде с применением спасательных судов при возникновении чрезвычайных ситуаций является одной из основных задач Единой государственной системы предупреждения и ликвидации чрезвычайных ситуаций (РСЧС), позволяющих уменьшить жертвы и сохранить здоровье людей. Спасение терпящих бедствие на воде должно быть организовано своевременно, оперативно и комплексно, то есть в полном объеме по всём необходимым в конкретной обстановке видам работ по спасению пострадавших.Conducting search and rescue operations on the water with the use of rescue vessels in the event of emergencies is one of the main tasks of the Unified State System for the Prevention and Elimination of Emergencies (RSES), which makes it possible to reduce casualties and preserve people's health. Salvation of those in distress on the water must be organized in a timely manner, promptly and in a comprehensive manner, that is, in full volume for all kinds of rescue work for the victims

Обеспечение безопасности радиоактивных источников на гипотетическом объекте

Объектом исследования является вопросы организации и функционирования систем физической защиты, учета и контроля ядерных материалов. Целью работы является создание методического подхода для описания и построения гипотетического объекта и его систем безопасности, с дальнейшем его применением в учебных целях по специальности Безопасность и нераспространение ядерных материалов.The object of research is the organization and functioning of systems of physical protection, accounting and control of nuclear materials. The aim of the work is to create a methodological approach to the description and construction of a hypothetical object and its security systems, with its further application for educational purposes in the specialty safety and non-proliferation of nuclear materials

Geometry, topology and dynamics of geodesic flows on noncompact polygonal surfaces

We establish the background for the study of geodesics on noncompact polygonal surfaces. For illustration, we study the recurrence of geodesics on $Z$-periodic polygonal surfaces. We prove, in particular, that almost all geodesics on a topologically typical $Z$-periodic surface with boundary are recurrent.Comment: 34 pages, 13 figures. To be published in V. V. Kozlov's Festschrif

The development of post-processing algorithm for the ultrasonic evaluation by the application of automated robotic testing systems

The implementation of automated testing systems based on six degrees of freedom (DOF) robotic manipulators is the actual trend in ultrasonic testing equipment development. Such systems are able to provide a fast ultrasonic evaluation with the respect of the surface of the testing object. In this work, the post-processing algorithm based on Synthetic Aperture Focusing Technique (SAFT) is suggested. Such algorithm allows presenting the results in the form of high-resolution imagery of the internal structure of testing objects. The suggested algorithm is applicable in the case of the utilization of automated testing systems based on six DOF robotic manipulators and takes into account all the features conditioned by such equipment application. Performance of the suggested algorithm was tested experimentally

Ergodic infinite group extensions of geodesic flows on translation surfaces

We show that generic infinite group extensions of geodesic flows on square tiled translation surfaces are ergodic in almost every direction, subject to certain natural constraints. Recently K. Fr\c{a}czek and C. Ulcigrai have shown that certain concrete staircases, covers of square-tiled surfaces, are not ergodic in almost every direction. In contrast we show the almost sure ergodicity of other concrete staircases. An appendix provides a combinatorial approach for the study of square-tiled surfaces

Non-stationary compositions of Anosov diffeomorphisms

Motivated by non-equilibrium phenomena in nature, we study dynamical systems whose time-evolution is determined by non-stationary compositions of chaotic maps. The constituent maps are topologically transitive Anosov diffeomorphisms on a 2-dimensional compact Riemannian manifold, which are allowed to change with time - slowly, but in a rather arbitrary fashion. In particular, such systems admit no invariant measure. By constructing a coupling, we prove that any two sufficiently regular distributions of the initial state converge exponentially with time. Thus, a system of the kind loses memory of its statistical history rapidly

Разработка модуля сбора и преобразования вибрации для питания беспроводных устройств на техногенных объектах

Конструирование модуля сбора и преобразования энергии вибрации для питания беспроводных датчиков технического диагностирования на техногенных объектахConstruction of a module for the collection and conversion of vibration energy for the supply of wireless sensors for technical diagnostics on industrial object

New technical approach for the repair of an abdominal wall defect after a transverse rectus abdominis myocutaneous flap: a case report

<p>Abstract</p> <p>Introduction</p> <p>Breast reconstruction with autologous tissue transfer is now a standard operation, but abnormalities of the abdominal wall contour represent a complication which has led surgeons to invent techniques to minimize the morbidity of the donor site.</p> <p>Case presentation</p> <p>We report the case of a woman who had bilateral transverse rectus abdominis myocutaneous flap (TRAM-flap) breast reconstruction. The surgery led to the patient developing an enormous abdominal bulge that caused her disability in terms of abdominal wall and bowel function, pain and contour. In the absence of rectus muscle, the large defect was repaired using a combination of the abdominal wall component separation technique of Ramirez et al and additional mesh augmentation with a lightweight, large-pore polypropylene mesh (Ultrapro^®).</p> <p>Conclusion</p> <p>The procedure of Ramirez et al is helpful in achieving a tension-free closure of large defects in the anterior abdominal wall. The additional mesh augmentation allows reinforcement of the thinned lateral abdominal wall.</p