Electron Transport in Double Quantum Dot governed by Nuclear Magnetic Field

We investigate theoretically electron transfer in a doble dot in a situation where it is governed by nuclear magnetic field: This has been recently achieved in experiment. We show how to partially compensate the nuclear magnetic field to restore Spin Blockade

Mitigating Denial-of-Service Attacks on VoIP Environment

IP telephony refers to the use of Internet protocols to provide voice, video, and data in one integrated service over LANs, BNs, MANs, not WANs. VoIP provides three key benefits compared to traditional voice telephone services. First, it minimizes the need fro extra wiring in new buildings. Second, it provides easy movement of telephones and the ability of phone numbers to move with the individual. Finally, VoIP is generally cheaper to operate because it requires less network capacity to transmit the same voice telephone call over an increasingly digital telephone network (FitzGerald & Dennis, 2007 p. 519). Unfortunately, benefits of new electronic communications come with proportionate risks. Companies experience losses resulting from attacks on data networks. There are direct losses like economic theft, theft of trade secrets and digital data, as well as indirect losses that include loss of sales, loss of competitive advantage etc. The companies need to develop their security policies to protect their businesses. But the practice of information security has become more complex than ever. The research paper will be about the major DoS threats the company’s VoIP environment can experience as well as best countermeasures that can be used to prevent them and make the VoIP environment and, therefore, company’s networking environment more secure

A Bayesian Model of Stress Assignment in Reading

The goal of the present thesis was to introduce a Bayesian model of stress assignment in reading. According to this model, readers compute probabilities of stress patterns by assessing prior beliefs about the likelihoods of stress patterns in a language and combining that information with non-lexical evidence for stress patterns provided by the word. The choice of a response is thought of as a random walk-type process which takes the system from a starting point to a response boundary. The calculated Bayesian probabilities determine the drift rate towards each boundary such that the probability of an error and the response latency are related to the posterior probabilities of the stress patterns. The Bayesian model of stress assignment was implemented for Russian disyllabic words. In Study 1, the distribution of stress patterns in a corpus of Russian disyllabic words (reflecting prior beliefs about the likelihoods of stress patterns) was analyzed. Further, non-lexical sources of evidence for stress in Russian were investigated. In Study 2, the effect of spelling-to-stress consistency of word endings on naming performance was examined. Study 3 was a binary logistic regression analysis of a set of predictors of stress patterns (length, log frequency, grammatical category, word onset complexity, word coda complexity, and spelling-to-stress consistency of six orthographic components) in a corpus of disyllabic words. In Study 4, a generalized linear mixed effects model with the same variables as predictors of stress assignment performance was applied to word naming data. Based on the combination of the results, it was concluded that there are three sources of evidence for stress in Russian: the first syllable, the second syllable, and the ending of the second syllable. The model was tested in two simulations. In Study 5, the predictions of the model were compared with stress assignment performance of speakers of Russian naming words. In Study 6, the model was tested on its ability to simulate stress assignment performance of readers naming nonwords. The model managed to predict not only the most frequent stress pattern that readers assigned, but also the relative ratio of trochaic versus iambic responses given by the participants

Efficient Magnetization Reversal with Noisy Currents

We propose to accelerate reversal of the ferromagnetic order parameter in spin valves by electronic noise. By solving the stochastic equations of motion we show that the current-induced magnetization switching time is drastically reduced by a modest level of externally generated current (voltage) noise. This also leads to a significantly lower power consumption for the switching process.Comment: 4 pages, 3 figure

Cross-script orthographic and phonological preview benefits

The present experiment examined the use of parafoveally presented first-language (LI) orthographic and phonological codes during reading of second-language (L2) sentences in proficient Russian-English bilinguals. Participants read English sentences containing a Russian preview word that was replaced by the English target word when the participant’s eyes crossed an invisible boundary located before the preview word. The use of English and Russian allowed us to manipulate orthographic and phonological preview effects independently of one another. The Russian preview words overlapped with English target words in (a) orthography (ВЕЛЮР [vʲɪˈlʲʉr]–BERRY), (b) phonology (БЛАНК [blank]–BLOOD), or (c) had no orthographic or phonological overlap (КАЛАЧ [kɐˈlat͡ɕ]–BERRY; ГЖЕЛЬ [ɡʐɛlʲ]–BLOOD). The results of this study showed a clear and strong benefit of the parafoveal preview of Russian words that shared either orthography or phonology with English target words. This study is the first demonstration of cross-script orthographic and phonological parafoveal preview benefit effects. Bilinguals integrate orthographic and phonological information across eye fixations in reading, even when this information comes from different languages

Loss Distribution Generation in Credit Portfolio Modeling

In the current paper we analyze several methods for generation of loss distribution for credit portfolios. Loss distributions play an important role in pricing of credit derivatives and in credit portfolio optimization. A loss distribution is a function of the number of entities in the portfolio, their credit ratings, the notional amount and recovery of each entity, default probabilities, loss given defaults, and the correlation/dependence structure between entities incorporated in the portfolio. Direct generation of loss distribution may require Monte Carlo simulation which is time consuming and is not effective when applied for credit portfolio optimization. To overcome computational complexity a number of approaches were undertaken based on assumptions imposed on the input parameters, goals of loss distributions generation, and the accepted level of tolerance and computational errors