Path-integral approach to mutual information calculation for nonlinear communication channel with small second dispersion at large signal-to-noise power ratio

We consider the information fiber optical channel modeled by the nonlinear Schrodinger equation with additive Gaussian noise. Using path-integral approach and perturbation theory for the small dimensionless parameter of the second dispersion, we calculate the conditional probability density functional in the leading and next-to-leading order in the dimensionless second dispersion parameter associated with the input signal bandwidth. Taking into account specific filtering of the output signal by the output signal receiver, we calculate the mutual information in the leading and next-to-leading order in the dispersion parameter and in the leading order in the parameter signal-to-noise ratio (SNR). Further, we find the explicit expression for the mutual information in case of the modified Gaussian input signal distribution taking into account the limited frequency bandwidth of the input signal.Comment: 42 pages, 5 figure

Deductive verification of requirements for event-driven architecture

The current paper presents the technology of processing of requirements for systems with event-driven architecture. The technology consists of the stages of formalization, formal verification and conversion to design specifications. The formalization is the formal description of events as formal specifications called basic protocols. The consistency and completeness of basic protocols, safety properties and user-defined properties are verified. The deductive tools for dynamic and static checking are used for detection of properties violation. The method of enlargement allows reducing the complexity of proving and solving. Formal presentation of requirements allows converting them to SDL\UML specifications and generating the test suite. The technology is realized in IMS system and applied in more than 50 projects of telecommunication, networking, microprocessing and automotive systems

MULTIFUNCTIONAL ANALOG DEVICE BASED ON AMPLIFIERS WITH REGULATED GAIN

In this article analog device capable to make portion of different functions in wide frequency band is discussed. Some recommendations for possible application examples are offered

Elementary amenable subgroups of R. Thompson's group F

The subgroup structure of Thompson's group F is not yet fully understood. The group F is a subgroup of the group PL(I) of orientation preserving, piecewise linear self homeomorphisms of the unit interval and this larger group thus also has a poorly understood subgroup structure. It is reasonable to guess that F is the "only" subgroup of PL(I) that is not elementary amenable. In this paper, we explore the complexity of the elementary amenable subgroups of F in an attempt to understand the boundary between the elementary amenable subgroups and the non-elementary amenable. We construct an example of an elementary amenable subgroup up to class (height) omega squared, where omega is the first infinite ordinal.Comment: 20 page

Interfering Doorway States and Giant Resonances. I: Resonance Spectrum and Multipole Strengths

A phenomenological schematic model of multipole giant resonances (GR) is considered which treats the external interaction via common decay channels on the same footing as the coherent part of the internal residual interaction. The damping due to the coupling to the sea of complicated states is neglected. As a result, the formation of GR is governed by the interplay and competition of two kinds of collectivity, the internal and the external one. The mixing of the doorway components of a GR due to the external interaction influences significantly their multipole strengths, widths and positions in energy. In particular, a narrow resonance state with an appreciable multipole strength is formed when the doorway components strongly overlap.Comment: 20 pages, LaTeX, 3 ps-figures, to appear in PRC (July 1997

Polymerization of Lactic Acid Using Microwave and Conventional Heating

The polymerization of lactic acid (LA) has been investigated by two methods: conventional heating and under microwave irradiation. The reactions of polymerization have been carried out in two stages: at the beginning water is removed and oligomer is obtained; then, the catalysts/co-catalysts are added and reactions are carried out. Tin octoate, toluene sulfonic acid, 2-aminopropanoic acid (alanine) have been investigated as polymerization catalysts and the derivatives of 2,4,6,8- tetramethilol -2,4,6,8- tetraazabicyclo[3.3.0]octane -3,7-dion (Tetraol), comprising atoms of Mg, Zn, Al have been synthesized for the first time. The structure of the synthesized catalyst has been investigated using the method of IR, {1}H NMR. It has been shown that the process of obtaining polylactic acid (PLA) by microwave irradiation proceeds hundreds of times faster. PLA samples synthesized by this method have the same optical characteristics as the PLA obtained by conventional heating

On micro-structural effects in dielectric mixtures

The paper presents numerical simulations performed on dielectric properties of two-dimensional binary composites on eleven regular space filling tessellations. First, significant contributions of different parameters, which play an important role in the electrical properties of the composite, are introduced both for designing and analyzing material mixtures. Later, influence of structural differences and intrinsic electrical properties of constituents on the composite's over all electrical properties are investigated. The structural differences are resolved by the spectral density representation approach. The numerical technique, without any {\em a-priori} assumptions, for extracting the spectral density function is also presented.Comment: 24 pages, 8 figure and 7 tables. It is submitted to IEEE Transactions on Dielectrics and Electrical Insulatio

The type numbers of closed geodesics

A short survey on the type numbers of closed geodesics, on applications of the Morse theory to proving the existence of closed geodesics and on the recent progress in applying variational methods to the periodic problem for Finsler and magnetic geodesicsComment: 29 pages, an appendix to the Russian translation of "The calculus of variations in the large" by M. Mors

Wanting to become PE teachers in Spain: connections between previous experiences and particular beliefs about school Physical Education and the development of professional teacher identities

Physical Education (PE) teachers have previous experiences that both shape their particular beliefs about the role and purpose of this school subject as well as their pedagogical practice. The present study aims to examine and deepen our knowledge of future Spanish PE teachers’ previous experiences of and beliefs about PE that condition their pedagogical practice and intentionality within this school subject. The data reported on in this paper were generated through questionnaires, life-history stories and semi-structured interviews with 24 initial teacher education students in the second year of a degree specialising in PE at a Spanish university. The data was analysed using content and narrative (thematic) analysis. The students, far from being tabula rasa, in their responses show how their previous socialisation period, their subjectivities and identities constitute particular beliefs about PE teaching. More specifically, the results reveal four key themes in the student teachers’ experiences and beliefs that represent four different factors influencing future PE teacher identities: (1) ‘Sport’; (2) ‘PE for health’; (3) ‘A focus on pedagogy’; and (4) ‘A critical orientation’. In conclusion, the study reaffirms the need for further reflection on how previous experiences and beliefs influence the development of professional teacher identities as part of initial teacher education in PE