5,180 research outputs found
O. Smirnova
No full textIntroduction Hadron production in the electron-positron annihilation at high energies always provided physicists with clean data samples, particularly convenient for various precision analyses. Studies of the multiparticle dynamics in hadronic decays of the fl =Z 0 brought up many interesting results 1 , being of a great importance for understanding of the hadronization process. At higher energies, when W + W \Gamma pairs can be produced, an issue of a "cross-talk" between two hadron sources became the very important point in correlation studies. All the four experiments at LEP, -- ALEPH, DELPHI, L3 and OPAL, conducted various studies of the fluctuations and correlations in phase space. Recently, a certain interest in studies of the Bose-Einstein correlations in particular in e + e \Gamma annihilation arose, following the appearance of the
Puškin et les carnets d'Aleksandra O. Smirnova
No full textDe Ponfilly Raymond. Puškin et les carnets d'Aleksandra O. Smirnova. In: Revue des études slaves, tome 59, fascicule 1-2, 1987. Alexandre Puškin, 1799-1837, sous la direction de Efim Etkind. pp. 101-108
Re-employment Probabilities and Wage Offer Function for Russian Labor Market
No full textThis research addresses labor market transformation in Russia. It elaborates on the theory of job search and focuses on the following issues: (1) evaluation of the re-employment probabilities (hazard rates) for different socio-economic groups; and (2) estimation of wage offer distribution for the transforming labor market. We use data from Phase II of the Russia Longitudinal Monitoring Survey (RLMS) to estimate the employment and wage offer functions for Russian workers who found a job after having been unemployed. We take into account the effectiveness of search strategies used and correct for truncation in wage offers. The binomial logit-OLS estimation method with sample selection bias correction on pooled data from Rounds 5-9 of RLMS is used. The factors considered are sex, education, experience, sector of employment and search methods’ success rate, which are hypothesized to capture the main determinants of job search behavior. The results show that individual characteristics, as well as the search method used, play a decisive role in the re-employment prospects of the unemployed. The private sector employment level is estimated to have the most powerful positive effect on the wage offer function. Russian women are less likely than men to find a job after being unemployed, and wage offers for women are estimated to be lower than for men.Russia, Transition, Job Search, Wage Offer Function, Hazard Rates
Development of Aerogel Additives for the Foundry Industry
No full textThe foundry industry produces castings by solidification of molten metal in sand or permanent moulds. Special sand cores are used to get specific cavities within the casting material. These cores have the negative shape of the required hole. Many cast defects are known to appear on account of the thermal, mechanical and/or chemical transformation of the sand cores. The thermal decomposition of the most often used organic binder system, leads to a strong gas evolution and the occurrence of special cast defects. To avoid this expensive and time consuming ceramic coatings are used. Alternatively the cast quality can be improved by refining the cores themselves using aerogels. Aerogels as nanostructured additives restrain many typical cast defects. Their large inner surface, high gas absorption capacity and lower thermal conductivity are able to minimize common defects in castings. Resulting exhaust gases can be bound physically or chemically on the inner surface. Within the last years granulated aerogels as additives lead to benefits in aluminum and brass alloy castings. Recently they enabled positive results even in grey cast iron. Due to the high casting temperatures, the different solidification behavior of bronze and the mechanical treatment at the bronze foundry industry aerogels as additives are exposed to different thermal and mechanical circumstances. They need to withstand temperatures above 1200-1300°C for a period of time and be stable under oxidizing conditions. Si-O-C aerogels could be synthesized by pyrolysis of the appropriate organic-inorganic hybrid system. They are stable under high temperatures and may be used as additives in bronze casting. The poster describes the synthesis of the Si-O-C aerogels, their thermal and mechanical properties as well as their ability of gas adsorption by measuring the inner surface
Comparative Analysis of Cryptocurrency Trading Platforms Using the Analytic Hierarchy Process
No full textIn the rapidly evolving world of cryptocurrency trading, selecting an optimal trading platform is paramount for both novice and seasoned investors. This study aims to provide a comprehensive evaluation of leading cryptocurrency trading platforms using the Analytic Hierarchy Process (AHP). The AHP, a structured technique for organizing and analyzing complex decisions, was employed to rank platforms based on multiple criteria, including UI/UX, security protocols, asset diversity, and more. Initial findings, considering equal importance for all criteria, highlighted Binance as the most favorable platform. However, when varying the importance of criteria based on empirical data, the distinctions between platforms became less pronounced, yet Binance retained its top position. This research not only offers valuable insights for potential investors but also emphasizes the significance of considering multiple criteria in decision-making processes. Furthermore, the study underscores the versatility of the AHP in evaluating multifaceted scenarios, making it a valuable tool for future research in diverse domains
Singular perturbations of Volterra equations with periodic nonlinearities: Stability and oscillatory properties
No full textSingularly perturbed integro-differential Volterra equations with MIMO periodic nonlinearities are considered, which describe synchronization circuits (such as phase- and frequency-locked loops) and many other “pendulum-like” systems. Similar to the usual pendulum equation, such systems are typically featured by infinite sequences of equilibria points, and none of which can be globally asymptotically stable. A natural extension of the global asymptotic stability is the gradient-like behavior, that is, convergence of any solution to one of the equilibria. In this paper, we offer an efficient frequency-domain criterion for gradientlike behavior. This criterion is not only applicable to a broad class of infinite-dimensional systems with periodic nonlinearities, but in fact ensures the equilibria set stability under singular perturbation. In particular, the proposed criterion guarantees the absence of periodic solutions that are considered to be undesirable in synchronization systems. In this paper we also discuss a relaxed version of this criterion, which guarantees the absence of “high-frequency” periodic solutions, whose frequencies lie beyond a certain bounded interval.Accepted Author ManuscriptTeam Tamas Keviczk
Volterra Equations with Periodic Nonlinearities: Multistability, Oscillations and Cycle Slipping
No full textIn this paper, systems of nonlinear integro-differential Volterra equations are examined that can be represented as feedback interconnections of linear time-invariant block and periodic nonlinearities. The interest in such systems is motivated by their numerous applications in mechanical, electrical and communication engineering; examples include, but are not limited to, models of phase-locked loops, pendulum-like mechanical systems, coupled vibrational units and electric machines. Systems with periodic nonlinearities are usually featured by multistability and have infinite sequences of (locally) stable and unstable equilibria; their trajectories may exhibit nontrivial (e.g. chaotic) behavior. We offer frequency-domain criteria, ensuring convergence of any solution to one of the equilibria points, and this property is referred to as the gradient-like behavior and corresponds to phase locking in synchronization systems. Although it is hard to find explicitly the equilibrium, attracting a given trajectory, we give a constructive estimate for the distance between this limit equilibrium and the initial condition. The relevant estimates are closely related to the analysis of cycle slipping in synchronization systems. In the case where the criterion of gradient-type behavior fails, a natural question arises-which nonconverging solutions may exist in the system and, in particular, how many periodic solutions it has. We show that a relaxation of the frequency-domain convergence criterion ensures the absence of high-frequency periodic orbits. The results obtained in the paper are based on the method of integral quadratic constraints that has arisen in absolute stability theory and stems from Popov's techniques of "a priori integral indices". We illustrate the analytic results by numerical simulations.</p
Software as storytelling: A systematic literature review
No full textStorytelling has always been a crucial, perhaps constitutive part of our lives. All communities have told stories. In recent years, software development is becoming increasingly recognized as a creative process that has a lot in common with the process of writing or telling a story. Aim: The objectives of this paper are: (a) to review and aptly classify current principles and approaches that describe software development as a form of storytelling; (b) to describe and understand the heuristic function of storytelling in software development; and (c) to discuss and single out the principles of storytelling that may play a role, hence constitute significant improvements to the practices of software developers. Method: To achieve these goals and objectives we conducted a systematic literature review of relevant scientific papers and subsequently analyzed them by means of a textual narrative synthesis. Results: More specifically, we retrieved, screened and examined 51 relevant publications. The synthesis we conducted allowed us to understand and better visualize the many interesting correspondences and analogies between those two seemingly different processes, namely storytelling and software development. In particular, in our work, we focused on describing and analyzing how certain principles underlying storytelling can be adapted and applied in current practices of software engineering. Conclusion: This paper presents and re-elaborates in a critical fashion and from a different angle a substantial body of knowledge and research recently carried out in the software development literature
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