212 research outputs found
Stability of relative equilibria with singular momentum values in simple mechanical systems
A method for testing -stability of relative equilibria in Hamiltonian
systems of the form "kinetic + potential energy" is presented. This method
extends the Reduced Energy-Momentum Method of Simo et al. to the case of
non-free group actions and singular momentum values. A normal form for the
symplectic matrix at a relative equilibrium is also obtained.Comment: Partially rewritten. Some mistakes fixed. Exposition improve
Local search heuristics for the multidimensional assignment problem
The Multidimensional Assignment Problem (MAP) (abbreviated s-AP in the case of s dimensions) is an extension of the well-known assignment problem. The most studied case of MAP is 3-AP, though the problems with larger values of s also have a large number of applications. We consider several known neighborhoods, generalize them and propose some new ones. The heuristics are evaluated both theoretically and experimentally and dominating algorithms are selected. We also demonstrate that a combination of two neighborhoods may yield a heuristics which is superior to both of its components
Electromagnetic field and radiation for a charge moving along a helical trajectory inside a waveguide with dielectric filling
We investigate the electromagnetic field generated by a point charge moving
along a helical trajectory inside a circular waveguide with conducting walls
filled by homogeneous dielectric. The parts corresponding to the radiation
field are separated and the formulae for the radiation intensity are derived
for both TE and TM waves. It is shown that the main part of the radiated quanta
is emitted in the form of the TE waves. Various limiting cases are considered.
The results of the numerical calculations show that the insertion of the
waveguide provides an additional mechanism for tuning the characteristics of
the emitted radiation by choosing the parameters of the waveguide and filling
medium.Comment: 17 pages, 9 figures, discussion, graphs, and references adde
Optical nanofibers and spectroscopy
We review our recent progress in the production and characterization of
tapered optical fibers with a sub-wavelength diameter waist. Such fibers
exhibit a pronounced evanescent field and are therefore a useful tool for
highly sensitive evanescent wave spectroscopy of adsorbates on the fiber waist
or of the medium surrounding. We use a carefully designed flame pulling process
that allows us to realize preset fiber diameter profiles. In order to determine
the waist diameter and to verify the fiber profile, we employ scanning electron
microscope measurements and a novel accurate in situ optical method based on
harmonic generation. We use our fibers for linear and non-linear absorption and
fluorescence spectroscopy of surface-adsorbed organic molecules and investigate
their agglomeration dynamics. Furthermore, we apply our spectroscopic method to
quantum dots on the surface of the fiber waist and to caesium vapor surrounding
the fiber. Finally, towards dispersive measurements, we present our first
results on building and testing a single-fiber bi-modal interferometer.Comment: 13 pages, 18 figures. Accepted for publication in Applied Physics B.
Changes according to referee suggestions: changed title, clarification of
some points in the text, added references, replacement of Figure 13
Изучение образовательных потребностей специалистов сферы обращения лекарственных средств
Early determination of educational needs of specialists is one of the most important tools of improving teaching and learning activities within the system of continuing professional education. For this purpose the Center of Educational Programmes of the FSBI «SCEEMP» has surveyed about 350 specialists engaged in the sphere of medicines circulation. The survey respondents participated in seminars and professional development programmes, which were provided by the Center of Educational Programmes in 2014. This article presents the results of this opinion poll.Своевременное выявление образовательных потребностей профильных специалистов является одним из важнейших инструментов совершенствования учебного процесса в системе дополнительного профессионального образования. С этой целью в Центре образовательных программ ФГБУ «НЦЭСМП» Минздрава России был выполнен социологический опрос более 350 специалистов, занятых в сфере обращения лекарственных средств и обучавшихся на тематических семинарах и программах повышения квалификации Центра образовательных программ в 2014 году. В данной статье представлены полученные результаты проведенного социологического опроса
СОВРЕМЕННЫЙ ВЗГЛЯД НА ЛЕЧЕНИЕ ТРОФИЧЕСКИХ ЯЗВ
Article is devoted to one of ancient sections of medicine treatment of wounds. However treatment is long not healing wounds and now remains to one of important problems of medicine. Terms of healing of ulcers at the majority of patients make 2–3 months, at a number of patients they don’t begin to live for years, and the frequency of recurrence at conservative treatment reaches 60–70%. Big prevalence of trophic ulcers and insufficient efficiency of existing conservative methods of treatment lead to the huge economic damage caused by disability.Статья посвящена одному из древних разделов медицины лечению ран. Однако лечение длительно незаживающих ран и в настоящее время остаётся одной из важных проблем медицины. Сроки заживления язв у большинства пациентов составляют 2–3 месяца, у ряда больных они не заживают годами, а частота рецидивов при консервативном лечении достигает 60–70%. Большая распространенность трофических язв и недостаточная эффективность существующих консервативных методов лечения приводят к огромному экономическому ущербу, вызванному потерей трудоспособности
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