Empirical evaluation of accuracy of mathematical software used for availability assessment of fault-tolerant computer systems

Dependability assessment is typically based on complex probabilistic models. Markov and semi-Markov models are widely used to model dependability of complex hardware/software architectures. Solving such models, especially when they are stiff, is not trivial and is usually done using sophisticated mathematical software packages. We report a practical experience of comparing the accuracy of solutions stiff Markov models obtained using well known commercial and research software packages. The study is conducted on a contrived but realistic cases study of computer system with hardware redundancy and diverse software under the assumptions that the rate of failure of software may vary over time, a realistic assumption. We observe that the disagreement between the solutions obtained with the different packages may be very significant. We discuss these findings and directions for future research

Hygienic requirements of urban living environment in the Russian Federation and in Italy: a comparison

Introduzione/scopo. La pianificazione urbana tende a contenere e regolamentare la crescita urbana consentendo uno sviluppo sostenibile a livello ambientale, sociale e sanitario. Nel presente lavoro gli autori hanno confrontato i quadri normativi della Federazione Russ e dell’Italia ponendo particolare attenzione agli aspetti urbani degli spazi abitativi. Metodo. Considerando la ponderosa produzione normativa nei due paesi, il lavoro ha preso in esame le normative a livello nazionale per l’Italia e federale per la Russia, tenendo principalmente conto dei seguenti aspetti: strumenti di pianificazione urbana e protezione ambientale e sanitaria degli spazi abitativi. Risultati. I problemi relativi alla sicurezza igienico-sanitaria dell’ambiente di vita in Russia sono essenzialmente riconducibili a due sistemi normativi (SNiP e SanPiN), mentre in Italia rientrano nel D.M. 05/07/1975. I principi fondamentali della pianificazione urbana in Russia sono dettati da una norma federale, mentre in Italia sono recepiti nel Piano Regolatore Generale (PRG) comunale e nei diversi regolamenti locali, dove si riasriassume tutta la normativa sovraordinata. Gli aspetti legati alla qualità ambientale, infine, in entrambi i paesi sono disciplinati da varie leggi specifiche (federali e statali); un articolato sistema di norme che tengono conto dei potenziali impatti sulla salute e sull’ambiente Conclusioni. Gli autori ritengono che dovrebbero essere sviluppati, specialmente in Italia che si trova nettamente più indietro da questo punto di vista, strumenti normativi chiari e aggiornati aventi per oggetto l’igiene degli edifici e degli ambienti urbani, basati sulle più recenti acquisizioni di letteratura scientifica internazionale nell’intento di garantire i più alti standard in materia di tutela della Salute Pubblica.Aim. Urban planning tries to contain and regulate the uncontrolled growth of cities, encouraging their sustainable development at environmental, social and health levels. In the present work, the authors compare the regulatory frameworks of the Russian Federation and of Italy, with particular attention paid to the urban aspects of living spaces. Method. Considering the extant normative production in the two countries, the authors examine national legislation for Italy and federal legislation for Russia, mainly taking into account the following aspects: urban planning tools and environmental and sanitary protection of living spaces. Results. Hygienic-sanitary requirements regarding living environment in Russia are essentially expressed by two regulatory systems (SNiP and SanPiN), while in Italy they are regulated by the D.M. 07/05/1975. The main principles of urban planning in Russia are expressed by federal standards, while in Italy they are incorporated in the Municipal General Plan (PRG) and in the various local regulations, where all the superordinate regulations are summarized. Finally, aspects related to environmental quality in both countries are governed by various specific laws (federal and state); a complex system of rules that take into account potential impacts on health and the environment. Conclusions. The authors reckon that clear and updated regulatory tools should be developed, especially in Italy that lags behind, regarding the building and urban hygiene, relying on the most recent acquisitions of international scientific literature in order to guarantee the highest standards in Public Health safeguard

Influence of contacts on the microwave response of a two-dimensional electron stripe

Electromagnetic response of a finite-width two-dimensional electron stripe with attached metallic side contacts is theoretically studied. It is shown that contacts substantially influence the position, the linewidth, and the amplitude of plasmon-polariton resonances in the stripe. In finite magnetic fields, absorption of the wave with the inactive circular polarization (which is not absorbed in an infinite system without contacts) may become larger than that of the wave with the active polarization. The results are discussed in view of recent microwave experiments in two-dimensional electron systems.Comment: 13 pages, incl. 9 figures, the paper has been substantially modified and extended, new results have been added. Accepted for publication in Phys. Rev.

Quantum-corrected ultraextremal horizons and validity of WKB in massless limit

We consider quantum backreaction of the quantized scalar field with an arbitrary mass and curvature coupling on ultraextremal horizons. The problem is distinguished in that (in contrast to non-extremal or extremal black holes) the WKB approximation remains valid near $r_{+}$ (which is the radius of the horizon) even in the massless limit. We examine the behavior of the stress-energy tensor of the quantized field near $r_{+}$ and show that quantum-corrected objects under discussion do exist. In the limit of the large mass our results agree with previous ones known in literature.Comment: revtex4, 9 page

Information processing using three-qubit and qubit-qutrit encodings of noncomposite quantum systems

We study quantum information properties of a seven-level system realized by a particle in an one-dimensional square-well trap. Features of encodings of seven-level systems in a form of three-qubit or qubit-qutrit systems are discussed. We use the three-qubit encoding of the system in order to investigate subadditivity and strong subadditivity conditions for the thermal state of the particle. The qubit-qutrit encoding is employed to suggest a single qudit algorithm for calculation of parity of a bit string. Obtained results indicate on the potential resource of multilevel systems for realization of quantum information processing.Comment: 6 pages, 3 figures; published versio

Технологические аспекты подготовки картографических материалов к публикации

Викладено основні технологічні особливості підготовки картографічних матеріалів до публікації. Розглянута технологія базується на існуючих в Україні досягненнях в галузі технічних і програмних засобів первинної обробки цифрових картографічних матеріалів та деяких закордонних засобах, які в нашій державі є досить популярними. Основними критеріями обраної технології є показники якості видання, витрати часу та фінансів на його підготовку.Sets out the main technological features of preparation of cartographic materials for publication. The technology considered is based on the existing achievements of Ukraine in the field of hardware and software for the primary processing of digital maps and some foreign media, which in our country is quite popular. The main criteria for the chosen technologies are indicators of the quality of publications, the cost of time and money on his training.Изложены основные технологические особенности подготовки картографических материалов к публикации. Рассмотренная технология базируется на существующих в Украине достижениях в области технических и программных средств первичной обработки цифровых картографических материалов и некоторых зарубежных средствах, которые в нашем государстве достаточно популярны. Основными критериями избранной технологии являются показатели качества издания, затраты времени и финансов на его подготовку

Чисельне розв’язання сингулярного інтегрального рівняння, пов’язаного з динамічною задачею контактної взаємодії

A singular integral equation with a fixed singularity to which the problem of contact interaction of two quarters of spaces in the conditions of harmonic oscillations of longitudinal shear is reduced is considered. A quarters of the space is situated so that the half-space composed of them has a stepped boundary. In the contact area, the conditions for ideal coupled are satisfied. The unknown function in this equation is the contact stresses. For the numerical solution of this equation, a method that takes into account the asymptotic behavior of contact stresses at the edge point is proposed. The basis of this method is the use of special quadrature formulas for singular integrals obtained in the article. When obtaining these formulas, the unknown function was approximated by an interpolation polynomial, in which the roots of the Laguerre polynomials are the points of interpolation. The values of the unknown function at the interpolation points are found by the collocation method, herewith the collocation points of collocationare the roots of the special function. An approximate formula for calculating contact stresses can have practical application. The effectiveness of the proposed method is demonstrated by the numerical example. Pages of the article in the issue: 93 - 96 Language of the article: UkrainianРозглядається сингулярне інтегральне рівняння з нерухомою особливістю, до якого зводиться задача контактної взаємодії двох чвертей простору в умовах гармонічних коливань повздовжнього зсуву. Чверті простору розміщуються так, що складений з них півпростір має ступінчасту межу. Для чисельного розв’язання цього рівняння запропоновано метод, який враховує справжню асимптотику розв’язку, використовує спеціальні квадратурні формули для сингулярних інтегралів і корені спеціальної функції у якості точок колокації

Can activation of TLR3 induce apoptosis in patients with miscarriages?

Objective - to estimate influence of TLR3 activation on apoptosis proteins in endometrium in patients with miscarriages and missed abortion