Dynamical models for dissipative localized waves of the complex Ginzburg-Landau equation

Finite-dimensional dynamical models for solitons of the cubic-quintic complex Ginzburg-Landau equation CGLE are derived. The models describe the evolution of the pulse parameters, such as the maximum amplitude, pulse width, and chirp. A clear correspondence between attractors of the finite-dimensional dynamical systems and localized waves of the continuous dissipative system is demonstrated. It is shown that stationary solitons of the CGLE correspond to fixed points, while pulsating solitons are associated with stable limit cycles. The models show that a transformation from a stationary soliton to a pulsating soliton is the result of a Hopf bifurcation in the reduced dynamical system. The appearance of moving fronts kinks in the CGLE is related to the loss of stability of the limit cycles. Bifurcation boundaries and pulse behavior in the regions between the boundaries, for a wide range of system parameters, are found from analysis of the reduced dynamical models. We also provide a comparison between various models and their correspondence to the exact results

A multilevel system of algorithms for detecting and isolating signals in a background of noise

Signal information is processed with the help of algorithms, and then on the basis of such processing, a part of the information is subjected to further processing with the help of more precise algorithms. Such a system of algorithms is studied, a comparative evaluation of a series of lower level algorithms is given, and the corresponding algorithms of higher level are characterized

Steady (robust) conditionally effective estimation of parameters

The concept of conditionally-effective estimation which provides optimum estimates for a given criterion in cases of given limitations is examined. The concept has the best accuracy for given limitation on the suitability of the algorithm concerning the deviation of the law governing error distribution from the proposed law. It is concluded that there must be a greater difference between individual algorithms in terms of difficulty, and that for the linear regression problem algorithms based on excluding lost points should be studied

Effects of Positive Emotions on Enhanced IT Use

Recently emotions started to receive more attention from IT use researchers. However, similarly to psychology, much of the focus goes to investigation of negative emotion influence. Drawing on broaden-and-build theory and flow theory, this manuscript aims to explore how positive emotions can influence enhanced IT use. In order to test it, experiment study is proposed. Findings are expected to support influence of positive emotions on enhanced IT use via state of flow. This suggests that organizations seeking to improve individual IT use should aim to stimulate positive emotions in individual users

Stable localized modes in asymmetric waveguides with gain and loss

It is shown that asymmetric waveguides with gain and loss can support a stable propagation of optical beams. This means that the propagation constants of modes of the corresponding complex optical potential are real. A class of such waveguides is found from a relation between two spectral problems. A particular example of an asymmetric waveguide, described by the hyperbolic functions, is analyzed. The existence and stability of linear modes and of continuous families of nonlinear modes are demonstrated.Comment: 10 pages, 4 figures. Accepted in Optics Letters, 201

Auction Design with Advised Bidders

This paper studies efficient and optimal auction design where bidders do not know their values and solicit advice from informed but biased advisors via a cheap-talk game. When advisors are biased toward overbidding, we characterize efficient equilibria of static auctions and equilibria of the English auction under the NITS condition (Chen, Kartik and Sobel (2008)). In static auctions, advisors transmit a coarsening of their information and a version of the revenue equivalence holds. In contrast, in the English auction, information is transmitted perfectly from types in the bottom of the distribution, and pooling happens only at the top. Under NITS, any equilibrium of the English auction dominates any efficient equilibrium of any static auction in terms of both efficiency and the seller's revenue. The distinguishing feature of the English auction is that information can be transmitted over time and bidders cannot submit bids below the current price of the auction. This results in a higher efficiency due to better information transmission and allows the seller to extract additional profits from the overbidding bias of advisors. When advisors are biased toward underbidding, there is an equilibrium of the Dutch auction that is more efficient than any efficient equilibrium of any static auction, however, it can bring lower expected revenue. Keywords auction design, cheap-talk, full revelation, english auction, communicatio

Tourism SME sustainability social and economic challenges during pandemic: cases of Russian Federation, Georgia and Latvia

. Until 2020, the tourism industry was characterized by a growth rate, the statistics highlight that globally 2019 was the tenth year with a consecutive annual growth. However, the Covid-19 pandemic marked a major turning point in the development of tourism, instead of tourism overdevelopment, the underdevelopment issues appeared in front pages of the industry news. The effects of the pandemic are intensified by the fact that tourism is a labour-intensive industry and that most companies in the sector are SMEs (small and medium sized enterprises). At this time, it is crucially important to look at sustainability issues, therefore the aim of this study is to analyse the social and economic dimensions of sustainability for tourism SMEs. Descriptive statistics as well as qualitative research methods were used to study the challenges posed by the pandemic, indepth interviews were conducted with tourism SMEs from three different countries. The conclusions show the situation from an enterprise perspective in Russian Federation, Georgia and Latvi