On the constrained KP hierarchy

An explanation for the so-called constrained hierarhies is presented by linking them with the symmetries of the KP hierarchy. While the existence of ordinary symmetries (belonging to the hierarchy) allows one to reduce the KP hierarchy to the KdV hierarchies, the existence of additional symmetries allows to reduce KP to the constrained KP.Comment: 7pp, LaTe

Negative high-frequency differential conductivity in semiconductor superlattices

We examine the high-frequency differential conductivity response properties of semiconductor superlattices having various miniband dispersion laws. Our analysis shows that the anharmonicity of Bloch oscillations (beyond tight-binding approximation) leads to the occurrence of negative high-frequency differential conductivity at frequency multiples of the Bloch frequency. This effect can arise even in regions of positive static differential conductivity. The influence of strong electron scattering by optic phonons is analyzed. We propose an optimal superlattice miniband dispersion law to achieve high-frequency field amplification

Generation of Relativistic Electron Bunches with Arbitrary Current Distribution via Transverse-to-Longitudinal Phase Space Exchange

We propose a general method for tailoring the current distribution of relativistic electron bunches. The technique relies on a recently proposed method to exchange the longitudinal phase space emittance with one of the transverse emittances. The method consists of transversely shaping the bunch and then converting its transverse profile into a current profile via a transverse-to-longitudinal phase-space-exchange beamline. We show that it is possible to tailor the current profile to follow, in principle, any desired distributions. We demonstrate, via computer simulations, the application of the method to generate trains of microbunches with tunable spacing and linearly-ramped current profiles. We also briefly explore potential applications of the technique.Comment: 13 pages, 17 figure

Multicscilling technologies in the system of continuous education

The article considers the application of multiskilling technologies in the system of continuous education. Examples of the use of multiskilling technologies in the training center of the Pervouralsky Novotrubny Plant are givenВ статье рассматривается применение технологий мультискиллинга в системе непрерывного образования. Приведены примеры использования технологий мультискиллинга в учебном центре Первоуральского новотрубного завод

Training of specialists in the educational centerof the enterprise as a way of designing a professional future

The article discusses the features of the system of training specialists relevant to the development of enterprises in the logic of the initiative FutureSkills Union WorldSkills Russia, taking into account the experience of the Educational training center group Chelyabinsk pipe rolling plantsРассматриваются особенности системы подготовки специалистов, актуальных для развития предприятий в логике инициативы FutureSkills союза WorldSkills Russia c учетом опыта образовательного учебного центра группы челябинских трубопрокатных заводо

Fermionic approach to the evaluation of integrals of rational symmetric functions

We use the fermionic construction of two-matrix model partition functions to evaluate integrals over rational symmetric functions. This approach is complementary to the one used in the paper ``Integrals of Rational Symmetric Functions, Two-Matrix Models and Biorthogonal Polynomials'' \cite{paper2}, where these integrals were evaluated by a direct method.Comment: 34 page

Dispersionful analogues of Benney's equations and NN-wave systems

We recall Krichever's construction of additional flows to Benney's hierarchy, attached to poles at finite distance of the Lax operator. Then we construct a ``dispersionful'' analogue of this hierarchy, in which the role of poles at finite distance is played by Miura fields. We connect this hierarchy with $N$-wave systems, and prove several facts about the latter (Lax representation, Chern-Simons-type Lagrangian, connection with Liouville equation, $\tau$-functions).Comment: 12 pages, latex, no figure

The using of modular training technology for training workers in the conditions of a corporate training center

The possibilities of modular training technology for solving the problem of forming the necessary professional competencies in corporate training organized on the basis of the dual system of education are shown. The experience of the corporate training center of the Chelyabinsk Tube Rolling Plant group is exemplified by the example of training workers in the profession ««Welder»Показаны возможности модульной технологии обучения для решения задачи формирования необходимых профессиональных компетенций в корпоративном обучении, организованном на основе дуальной системы образования. Приведен опыт корпоративного учебного центра группы Челябинских трубопрокатных заводов на примере подготовки рабочих по профессии «Сварщик

Quantum symmetries and exceptional collections

We study the interplay between discrete quantum symmetries at certain points in the moduli space of Calabi-Yau compactifications, and the associated identities that the geometric realization of D-brane monodromies must satisfy. We show that in a wide class of examples, both local and compact, the monodromy identities in question always follow from a single mathematical statement. One of the simplest examples is the Z_5 symmetry at the Gepner point of the quintic, and the associated D-brane monodromy identity