255 research outputs found

    Vertex algebras and the Landau-Ginzburg/Calabi-Yau correspondence

    Full text link
    We construct a spectral sequence that converges to the cohomology of the chiral de Rham complex over a Calabi-Yau hypersurface and whose first term is a vertex algebra closely related to the Landau-Ginburg orbifold. As an application, we prove an explicit orbifold formula for the elliptic genus of Calabi-Yau hypersurfaces.Comment: Latex, 50p. Some typos corrected, the page size may have been fixed. One new result, a theorem on the vertx algebra structure of the Landau-Ginzburg orbifold appears in sect. 5.2.18. This is the final version to appear in the Moscow Mathematical Journa

    Deformations of chiral algebras and quantum cohomology of toric varieties

    Full text link
    We reproduce the quantum cohomology of toric varieties (and of some hypersurfaces in projective spaces) as the cohomology of certain vertex algebras with differential. The deformation technique allows us to compute the cohomology of the chiral de Rham complex over the projective space.Comment: we use the deformation technique from the earlier version of this note to compute the cohomology of the chiral de Rham complex over the projective space; the two new results, Theorems 2.5A and B, are explained in sect. 2.

    Promoting local cultural initiatives with information and communication technologies

    Get PDF

    The Comparison of Two Calculation Methods of Billets Heating in Furnaces with the Help of Zone and FVM Methods

    Get PDF
    The comparison of two modelling methods for radiation heat exchange – finite volume and zonal methods – has been provided. The mathematical model of heating concast bars ring furnace has been created. Modelling of different heat modes of this furnace has been completed. In the result of modelling, it is shown that these methods demonstrate similar accuracy of obtained temperature values (not exceeding 50∘C). The calculation time of FVM method is greater than zonal method to 13%, because recalculations of absorption coefficients by EWBM method is needed. Keywords: radiation transfer, mathematical modeling, zonal method, discrete transfer zonal metho

    Simulation of the solidification of the melt in the Vanyukov furnace in the case of emergency stoppage

    Full text link
    A mathematical model of the Vanyukov furnace, which makes it possible to predict the behavior of an object in the emergency operational mode (upon the disconnection of the oxygen supply) and develop an effective system of additional heating which damps the consequences of the emergency mode and lowers the costs for the renovation of the furnace operation, is created. It is shown how solidification upon cooling the furnace with time is simulated using the enthalpy and porosity method. The mathematical model is adopted for existing production conditions, which are weakly defined. The energy characteristics of the mode for the solidifying furnace bath, which ensures its holding for a long time in the ready state to rapid firing, are found. Thus, the problem of excessively expensive furnace firing after prolonged production stoppage is solved in the conjugated statement with a calculation of the heating system of the overbath space. © 2013 Allerton Press, Inc

    PROBLEMS OF TEACHING HUMAN ANATOMY AT THE MODERN STAGE AND THE WAYS OF THEIR SOLUTIONS

    Get PDF
    For quality teaching human anatomy to students, it is necessary to emphasize the efficient use and combination of traditional methods with various forms of integration of test control. Through the details of the study of the organs structure on natural preparations, with their wider use, it is necessary to distinguish clinical aspects: introduction to the educational process of acquaintance with the data of various clinical situations using the example of the use of situational tasks «Krok-1». This is precisely the way which is methodically substantiated for the optimization and scientific organization of the modern educational process at the human anatomy departments. Aim and tasksof this work was to reveal the essence and characteristics of teaching human anatomy in modern conditions, identifying the shortcomings and advantages of the updated approaches to teaching, introduced in the educational process, and rethinking the traditional teaching methods with various forms of integration of modern techniques. Methods and results of the study. Efficient use and combination of traditional methods with various forms of integration of test control (but not prevailing) is the methodically substantiated way of optimization and scientific organization of the educational process in the applied study of anatomy as the foundation of medicine. This method of conducting classes and monitoring students knowledge gives them an opportunity to learn as much material as possible and encourages them to process data of all sections of the subject by themselves which is necessary for obtaining the profession of a doctor in the futur

    ИССЛЕДОВАНИЕ УРОВНЯ ИНФОРМАЦИОННОЙ БЕЗОПАСНОСТИ СЕТЕВЫХ СИСТЕМ ВИДЕОНАБЛЮДЕНИЯ

    Get PDF
    The main elements of the structure of the network videosurveillance systems has been described. The statistical study on the criterion of proximity has been performed: the predominant use on the objects of different categories in the Republic of Belarus. The testing of network videosurveillance systems for ability to conduct remote attacks on information and telecommunications networks has been provided.Рассмотрены основные элементы структуры сетевых систем видеонаблюдения. Проведено статистическое исследование по критерию близости: преимущественное использование на объектах различных категорий в Республике Беларусь. Выполнено тестирование сетевых систем видеонаблюдения на предмет возможности проведения удаленных атак по информационно-телекоммуникационным сетям

    Concept and nature of subjects of prevention and counteraction of third party activities in Ukraine: administrative and legal aspects

    Get PDF
    Маліков, В. В. Поняття та види суб`єктів запобігання та протидії терористичній діяльності в Україні: адміністративно-правовий аспект / В. В. Маліков // Науковий вісник Ужгородського національного університету. Серія: Право . - 2017. - Вип. 43, т. 4. - С. 241-244.В статті на підставі дослідження теоретичних здобутків надано визначення суб’єкта запобігання та протидії терористичній діяльності, та виокремлено основні ознаки. Аналіз норм чинного законодавства дозволив сформулювати систему суб’єктів запобігання та протидії терористичній діяльності: 1) загальні суб’єкти; 2) спеціально створенні суб’єкти для протидії терористичній діяльності; 3) додаткові суб’єкти, які мають повноваження щодо запобігання терористичній діяльності; 4) суб’єкти, які не мають відповідних повноважень, але в зв’язку з необхідністю залучаються до такої діяльності.In the article, on the basis of the study of theoretical achievements, the definition of the subject of prevention and counteraction to terrorist activity was given, and the main features were singled out. Analysis of the norms of the current legislation allowed formulating the system of subjects of prevention and counteraction to terrorist activity: 1) general subjects; 2) specially created entities for counteracting terrorist activity; 3) additional entities that have the authority to prevent terrorist activity; 4) entities that do not have the appropriate authority, but are required to be involved in such activities.В статье на основании исследования теоретических достижений дано определение субъекта предотвращения и противодействия террористической деятельности, и выделены основные признаки. Анализ норм действующего законодательства позволил сформулировать систему субъектов предупреждения и противодействия террористической деятельности: 1) общие субъекты; 2) специально созданные субъекты для противодействия террористической деятельности; 3) дополнительные субъекты, имеющие полномочия по предотвращению террористической деятельности; 4) субъекты, которые не имеют соответствующих полномочий, но в связи с необходимостью привлекаются к такой деятельности
    corecore