О надежности, безопасности и читабельности языков программирования на примере языка Ада

A few small suggestions of language design reflect the author's views are presented. These suggestions are mainly related to the reliability and safety of simple, typical structures and statements in programming: typification, compile-time elaborations of variables, status of variables, high-level statements, etc. The programmers often spend working time with similar constructions. From mathematical point of view these suggestions do not effect seriously on the complexity and efficiency of calculations; they are designed exclusively to help a programmer to write reliable, secure and clear programs. These suggestions are illustrated on Ada language, which is very suitable for this purpose, but they can be applied in other languages also.Представлены несколько небольших предложений, которые относятся к проектированию языков и отражают взгляды автора на данный предмет. Эти предложения затрагивают надежность, ясность и безопасность типичных, простых конструкций языков программирования, таких как, например, типизация, начальная элаборация, статус переменных, некоторые высокоуровневые операторы и пр. Часто программисты тратят много времени на работу с подобными конструкциями. Представленные предложения мало влияют на сложность и эффективность вычислений. Они предлагаются исключительно для помощи программисту в создании надежных и безопасных программ. Предложения иллюстрируются примерами на языке Ада, который очень удобен для этого, но они могут быть применены и в других языках

Connecting does not necessarily mean learning: Course handbooks as mediating tools in school-university partnerships

This is the author's accepted manuscript (titled "Course handbooks as mediating tools in learning to teach"). The final published article is available from the link below. Copyright @ 2011 American Association of Colleges for Teacher Education.Partnerships between schools and universities in England use course handbooks to guide student teacher learning during long field experiences. Using data from a yearlong ethnographic study of a postgraduate certificate of education programme in one English university, the function of course handbooks in mediating learning in two high school subject departments (history and modern foreign languages) is analyzed. Informed by Cultural Historical Activity Theory, the analysis focuses on the handbooks as mediating tools in the school-based teacher education activity systems. Qualitative differences in the mediating functions of the handbooks-in-use are examined and this leads to a consideration of the potential of such tools for teacher learning in school–university partnerships. Following Zeichner’s call for rethinking the relationships between schools and universities, the article argues that strong structural connections between different institutional sites do not necessarily enhance student teacher learning

РАВНОВЕСНОЕ РАСПРЕДЕЛЕНИЕ БОРА МЕЖДУ МЕТАЛЛОМ СИСТЕМЫ FE - C - SI - AL И БОРСОДЕРЖАЩИМ ШЛАКОМ

Using the HSC 6.1 Chemistry software package (Outokumpu) and simplex-lattice planning, the thermodynamic modeling of the boron equilibrium distribution between iron containing 0.2 % of C, 0.35 % of Si, 0.028 % of Al (in the terms and hereinafter indicated mass. %) and slag of the system СаО – SiO2 – Аl2O3 – 8 % МgO – 4 % В2O3 was carried out in a wide range of chemical composition and at temperatures of 1550 °С and 1600 °С. Adequate mathematical models in the form of III degree polynomial obtained for each temperature, describes the equilibrium distribution of boron between slag and metal depending on the slag composition. Mathematical modeling results are presented graphically in the form of diagrams of composition – boron equilibrium distribution. It is shown that slag basicity affects on the boron distribution coefficient. Thus, increasing the slag basicity from 5 to 8 at temperature of 1550 °С reduces the boron distribution coefficient from 160 to 120 and, as a consequence, increase the boron content in the metal from 0.021 % at LB = 159 to 0.026 % at LB = 121, that is, growth slag basicity is beneficial to the development of boron recovery process. The positive effect of the slag basicity on boron recovery process in the researched range of the chemical composition can be explained according to the slag phase composition and thermodynamics of boron reduction reactions. The temperature growth of the metal negatively affects the boron recovery. Equilibrium boron distribution coefficient increases by an average of 10 units with an increase in temperature to 1600 °C. The diagrams contain marked field of slag chemical composition with 53 – 58 % of CaO, 8.5 – 10.5 % of SiO2 and 20 – 27 % of Al2O3, providing boron distribution coefficients at level of 140 – 170 at temperature range of 1550 – 1600 °C and allowing to expect boron concentration in the metal at the level of 0.020 % at LB = 168 % and 0.023 % at LB = 139 at the 4 % of B2O3 in the slag initial. © 2017 National University of Science and Technology MISIS. All rights reserved

Employing culturally responsive pedagogy to foster literacy learning in schools

 In recent years it has become increasingly obvious that, to enable students in schools from an increasingly diverse range of cultural backgrounds to acquire literacy to a standard that will support them to achieve academically, it is important to adopt pedagogy that is responsive to, and respectful of, them as culturally situated. What largely has been omitted from the literature, however, is discussion of a relevant model of learning to underpin this approach. For this reason this paper adopts a socio-cultural lens (Vygotsky, 1978) through which to view such pedagogy and refers to a number of seminal texts to justify of its relevance. Use of this lens is seen as having a particular rationale. It forces a focus on the agency of the teacher as a mediator of learning who needs to acknowledge the learner’s cultural situatedness (Kozulin, 2003) if school literacy learning for all students is to be as successful as it might be. It also focuses attention on the predominant value systems and social practices that characterize the school settings in which students’ literacy learning is acquired. The paper discusses implications for policy and practice at whole-school, classroom and individual student levels of culturally-responsive pedagogy that is based on a socio-cultural model of learning. In doing so it draws on illustrations from the work of a number of researchers, including that of the author

Усечение падающего поля в задаче рассеяния электромагнитных волн на случайных поверхностях конечной длины

Introduction. An analysis of radio wave scattering over random surfaces frequently involves integral equations, which are solved by numerical methods. These methods are feasible only provided limited dimensions of the surface. The requirement of surface limitation leads to the appearance of edge currents, resulting in significant errors when calculating the radar cross section (RCS), particularly for grazing incident angles. The influence of edge currents is reduced by a function tapering the incident field amplitude. This function should satisfy the following requirements: to provide a low suppression of the field along the entire finite-size surface between its edges at the same time as decreasing the incident field amplitude to negligible values when approaching the edges. The incident field under the application of the tampering function should satisfy the wave equation with a minimum error. Although various tapering functions are applied for incident field amplitude (i.e. Gaussian, Thorsos, integral), none of them satisfies the aforementioned requirements.Aim. To suggest a novel function for tapering the amplitude of an electromagnetic wave incident on a perturbed finite-size surface when calculating RCS. In comparison with the known functions, the proposed function must satisfy the entire set of requirements.Materials and methods. A comparison of the proposed tapering function for incident field amplitude with the known tapering functions was performed, including the estimation of the error of satisfying the wave equation. To prove the applicability of the proposed tapering function, a mathematical modeling of the bistatic scatter diagram of a two-dimensional sea-like finite surface with a spatial Elfouhaily spectrum was carried out using Monte Carlo calculations in the Matlab environment.Results. Compared to the known tapering functions, the proposed tapering function satisfies the entire set of requirements. The results of mathematical modeling showed that the proposed function for tapering the incident field amplitude provides acceptable accuracy of estimating the RCS of finite-size random surfaces.Conclusion. A novel function for tapering the incident field amplitude was derived. This function reduces the influence of edge currents on the accuracy of RCS estimation of two-dimensional finite-size random surfaces, thus being instrumental for solving scattering problems.Введение. При анализе рассеяния радиоволн на случайных поверхностях часто используют интегральные уравнения, решаемые численными методами, работоспособными лишь при ограничении размеров поверхности. Указанное ограничение приводит к появлению краевых токов, которые, в свою очередь, вызывают существенные ошибки в расчетах эффективной площади рассеяния (ЭПР), особенно при скользящих углах облучения. Для снижения влияния краевых токов обычно используют функцию усечения падающего поля, которая должна удовлетворять совокупности требований – обеспечивать малое подавление поля по всей площади поверхности конечного размера между ее краями и одновременно снижение амплитуды поля до пренебрежимо малых значений при приближении к этим краям. Падающее поле с используемой функцией усечения должно удовлетворять волновому уравнению с минимальной погрешностью. Известны различные функции усечения падающей волны (гауссовская, Торсоса, интегральная), однако ни одна из них полностью не удовлетворяет предъявляемым требованиям.Цель работы. Предложить новую функцию усечения амплитуды электромагнитной волны, падающей на возмущенную поверхность ограниченного размера, для расчета ее ЭПР. По сравнению с известными функциями усечения новая функция должна удовлетворять всей совокупности предъявляемых требований.Материалы и методы. Выполнено сравнение предложенной функции усечения амплитуды падающего поля с известными функциями усечения, в том числе проведена оценка погрешности удовлетворения волновому уравнению. Для доказательства применимости предложенной функции усечения в среде MatLab выполнено математическое моделирование бистатической диаграммы рассеяния двумерной морской поверхности конечной длины с пространственным спектром Эльфохейли методом Монте-Карло.Результаты. Установлено, что предложенная функция усечения амплитуды падающего поля удовлетворяет предъявляемым требованиям лучше известных функций. Результаты математического моделирования показали, что новая функция обеспечивает приемлемую точность оценки ЭПР случайных поверхностей конечной длины.Заключение. Получена новая функция усечения амплитуды падающего поля для уменьшения влияния краевых токов на точность оценки ЭПР двумерных случайных поверхностей конечной длины, которая рекомендуется к использованию при решении задачи рассеяния

Application of adaptive tools in relaparotomy wound surgery

Aim. To evaluate the clinical effectiveness of the developed adaptive tools for mechanical treatment of wound surface and suturing of relaparotomy wounds. Methods. 55 patients aged 43 to 79 years after relaparotomy operated on for various acute surgical diseases of the abdominal cavity were treated. In the main group (n=22. average age 63.5±4.75 years) in uncomplicated and complicated course of the wound process after relaparotomy for treatment of the wound surface and wound closure, adaptive tools were used as proposed by the authors. In the comparison group (n=33, average age 62±6 years; p=0.98) traditional mechanical methods of wound defect sanation and wound suturing (simple nodal, 8-shaped and U-shaped sutures) were used. Monitoring of relaparotomy wound healing was performed using an ultrasound method. The analysis of postoperative local complications in the discussed groups of patients was carried out according to Clavien-Dindo classification. Results. In patients of the main group, the multiplicity of wound surface treatment decreased by 1.8 times compared to the comparison group. There were no cases of damage to the underlying tissues of the wound edges. Wound postoperative complications corresponded to severity grade I, II, and IIIa according to Clavien-Dindo classification: in the main group - 27.3% and in the comparison group - 54.5%. Suppuration occurred respectively in 9.1 and 33.3% of patients (p=0.049). Conclusion. The developed adaptive tools are safe and effective mechanical means of prevention of wound postoperative complications after relaparotomy

Новая возможность применения бактериофагов для профилактики инфекционных осложнений при свободной кожной пластике (бактериофаги при кожной пластике)

 Aim. To prevent infectious processes in the area of a recipient wound in free skin grafting with a split-graft.Materials and methods. A method was developed for immobilizing bacteriophages in the area of split thickness skin grafts through transferring a solution containing bacteriophages into a gel form. Microbiological and clinical studies of the effectiveness of the proposed method were performed.Results. The viability of bacteriophages in a gel dressing for up to 4 days was confirmed, as well as the reduced likelihood of local infectious complications in skin grafting.Conclusion. The gel composition containing bacteriophages allows quick response to changes in current hospital microflora and effectively counteract the dangers of nosocomial infection.  Цель. Профилактика инфекционного процесса в области реципиентной раны при свободной кожной пластике расщепленным трансплантатом.Материалы и методы. Разработан способ иммобилизации бактериофагов в области аутодермотрансплантата путем перевода раствора, содержащего бактериофаги, в гелевую форму. Выполнены микробиологические и клинические исследования эффективности предложенного способа.Результаты. Подтверждена жизнеспособность бактериофагов в гелевой повязке в сроки до 4 сут и снижение вероятности развития местных инфекционных осложнений при кожной пластике.Заключение. Гелевая композиция, содержащая бактериофаги, позволяет оперативно реагировать на изменения актуальной  госпитальной микрофлоры и эффективно противодействовать  опасности нозокомиального инфицирования.