Оценка противоречивости логической структуры учебного плана

Purpose of the study. The main purpose of creating a curriculum is to regulate academic disciplines in accordance with the logic of the learning process, defined by the relationship between the basic concepts of the disciplines. Violation of this logic becomes apparent only directly during the training sessions.A large variety of quantitative methods uses indicators that do not reveal structural deficiencies in the curriculum. This makes it difficult to improve the curriculum.The purpose of this work is to demonstrate the application of a general approach to the assessment of the structural inconsistency of systems in relation to the evaluation of the logical structure of the curriculum.Materials and methods. The paper applies a general approach to the assessment of structural integrity, developed on the basis of the provisions of the general theory of systems and graph theory. The approach involves the construction of three interrelated structural models of the system and using them to determine the initial data for calculating the index of inconsistency of the system structure.Results. The overall approach to the assessment of structural integrity is adapted to assess the logical structure of the curriculum. Three models of curriculum structure are developed:Elementary model of interdisciplinary communication;Curriculum network model;Hierarchical curriculum model.Based on the parameters of the hierarchical curriculum model, using three adapted algorithms, the value of the inconsistency index of the curriculum structure in the direction of preparation “Applied Informatics” is calculated. Recommendations on changing the structure of the studied curriculum to reduce the degree of its structural inconsistency are proposed. Conclusion. As a result of the research, the methods were proposed that allow identifying possible contradictions in the structure of the curriculum and evaluating its inconsistency. As the experiments have shown, it is extremely difficult to study the curricula in a manual manner, the number of disciplines in which exceeds 50. In this regard, the development of a complex of computer programs that will automate the assessment of the inconsistency of large curricula is being completed.Цель исследования. Основной целью создания учебного плана является упорядочение учебных дисциплин в соответствии с логикой процесса обучения, определенной взаимосвязями между основными понятиями дисциплин. Нарушение данной логики становится очевидным только непосредственно в ходе проведения учебных занятий.Большое разнообразие количественных методов используют показатели, которые не позволяют выявить структурные недоработки учебного плана. Это затрудняет процесс улучшения учебного плана.Целью данной работы является продемонстрировать применение общего подхода к оценке структурной противоречивости систем применительно к оценке логической структуры учебного плана.Материалы и методы. В работе применен общий подход к оценке структурной целостности, разработанный на основе положений общей теории систем и теория графов. Подход предусматривает построение трех взаимосвязанных структурных моделей системы и определения с их помощью исходных данных для расчета показателя противоречивости структуры системы.Результаты. Общий подход к оценке структурной целостности адаптирован для оценки логической структуры учебного плана. Разработаны три модели структуры учебного плана:– элементарная модель междисциплинарных связей;– сетевая модель учебного плана;– иерархическая модель учебного плана.На основе параметров иерархической модели учебного плана с использованием трех адаптированных алгоритмов рассчитано значение показателя противоречивости структуры учебного плана по направлению подготовки Прикладная информатика. Предложены рекомендации по изменению структуры исследуемого учебного плана для понижения степени его структурной противоречивости.Заключение. В результате проведенных исследований предложена методика, которая позволяет выявить возможные противоречия в структуре учебного плана и дать оценку его противоречивости.Как показали проведенные эксперименты, исследовать ручным способом учебные планы, количество дисциплин в которых превышает 50, крайне сложно. В связи с этим завершается разработка комплекса компьютерных программ, которые позволят автоматизировать оценку противоречивости больших учебных планов

NbS3_{3}: A unique quasi one-dimensional conductor with three charge density wave transitions

Through transport, compositional and structural studies, we review the features of the charge-density wave (CDW) conductor of NbS$_{3}$ (phase II). We highlight three central results: 1) In addition to the previously reported CDW transitions at $T_{P1}$ = 360\,K and $T_{P2}$ = 150\,K, another CDW transition occurs at a much higher temperature $T_{P0}$ = 620-650\,K; evidence for the non-linear conductivity of this CDW is presented. 2) We show that CDW associated with the $T_{P2}$ - transition arises from S vacancies acting as donors. Such a CDW transition has not been observed before. 3) We show exceptional coherence of the $T_{P1}$-CDW at room-temperature. Additionally, we report on the effects of uniaxial strain on the CDW transition temperatures and transport.Comment: 16 pages, 18 figure

Nb S3: A unique quasi-one-dimensional conductor with three charge density wave transitions

© 2017 American Physical Society.We review the features of the charge density wave (CDW) conductor NbS3 (phase II) and include several additional results from transport, compositional, and structural studies. Particularly, we highlight three central results: (1) In addition to the previously reported CDW transitions at TP1=360K and TP2=150K, a third CDW transition occurs at a much higher temperature TP0≈620-650K; evidence for the nonlinear conductivity of this CDW is presented. (2) We show that the CDW associated with the TP2 transition arises from S vacancies acting as donors. Such a CDW transition has not been observed before. (3) We demonstrate the exceptional coherence of the TP1 CDW at room temperature. The effects of uniaxial strain on the CDW transition temperature and transport are reported

Кристалл Er3+,Yb3+:YGdSiO5 для лазеров спектрального диапазона 1,5–1,6 мкм

Solid-state erbium lasers, emitting in the spectral range of 1.5–1.6 µm, are of great interest for several industrial applications. Nowadays the Er:glass is the most widespread laser material for obtaining laser radiation at the wavelength near 1.5 µm. However, the maximal output powers of such lasers are restricted by hundreds of milliwatts because low thermal characteristics of the glass host. By this reason the search for new crystalline hosts doped with erbium ions is the actual task.In this article the investigation results of spectroscopic properties of Er3+,Yb3+:YGdSiO5 (YGSO) crystals are reported. Polarized absorption and luminescence spectra were measured. The lifetimes of energy levels were determined. The excited state absorption spectra were measured. It was shown that excited state absorption band does not overlap with gain band in the range 1.5–1.6 µm. The energy transfer efficiency from ytterbium to erbium ions was estimated. The stimulated emission and gain cross-section spectra for Er3+ ions in YGSO were calculated.Твердотельные эрбиевые лазеры, излучающие в спектральной области 1,5–1,6 мкм, представляют большой интерес для различных практических применений. Из доступных на сегодня лазерных материалов для получения стимулированного излучения в области 1,5 мкм наибольшее распространение получили фосфатные стёкла, легированные ионами Er3+. Однако максимальные выходные мощности таких лазеров ограничены несколькими сотнями милливатт из-за низких термических характеристик стекла, поэтому поиск подходящей кристаллической матрицы для ионов эрбия является актуальным и в настоящее время.В работе представлены результаты исследований спектроскопических свойств кристалла иттрий-гадолиниевого силиката, легированного ионами эрбия и иттербия – Er3+,Yb3+:YGdSiO5 (YGSO). Измерены спектры поглощения и люминесценции в поляризованном свете, определены времена жизни возбуждённых состояний активных ионов. Измерения спектров поглощения из возбуждённого состояния показали, что полоса поглощения из возбуждённого состояния не перекрывается с полосой усиления в спектральной области 1,5–1,6 мкм. Проведена оценка эффективности переноса энергии от ионов иттербия к ионам эрбия. Выполнен расчёт спектров поперечных сечений вынужденного излучения и усиления

Synthesis of the Orthorhombic Dy1-xHoxMnO3 Single Crystals and Study of Their Magnetic Properties

In this report we prepared for the first time the orthorhombic Dy1-xHoxMnO3 single crystals with x = 0, 0.1, 0.2, 0.3, and 0.4 using the flux technique. The post-growth processing and chemical and structural characterization of the synthesized samples were performed. Also we examined the samples obtained by their magnetic properties and the magnetic anisotropy in wide ranges of temperatures and magnetic fields

Inconsistency evaluation of the curriculum logical structure

Purpose of the study. The main purpose of creating a curriculum is to regulate academic disciplines in accordance with the logic of the learning process, defined by the relationship between the basic concepts of the disciplines. Violation of this logic becomes apparent only directly during the training sessions.A large variety of quantitative methods uses indicators that do not reveal structural deficiencies in the curriculum. This makes it difficult to improve the curriculum.The purpose of this work is to demonstrate the application of a general approach to the assessment of the structural inconsistency of systems in relation to the evaluation of the logical structure of the curriculum.Materials and methods. The paper applies a general approach to the assessment of structural integrity, developed on the basis of the provisions of the general theory of systems and graph theory. The approach involves the construction of three interrelated structural models of the system and using them to determine the initial data for calculating the index of inconsistency of the system structure.Results. The overall approach to the assessment of structural integrity is adapted to assess the logical structure of the curriculum. Three models of curriculum structure are developed:Elementary model of interdisciplinary communication;Curriculum network model;Hierarchical curriculum model.Based on the parameters of the hierarchical curriculum model, using three adapted algorithms, the value of the inconsistency index of the curriculum structure in the direction of preparation “Applied Informatics” is calculated. Recommendations on changing the structure of the studied curriculum to reduce the degree of its structural inconsistency are proposed. Conclusion. As a result of the research, the methods were proposed that allow identifying possible contradictions in the structure of the curriculum and evaluating its inconsistency. As the experiments have shown, it is extremely difficult to study the curricula in a manual manner, the number of disciplines in which exceeds 50. In this regard, the development of a complex of computer programs that will automate the assessment of the inconsistency of large curricula is being completed

Peculiarities of Formation and Physico-Mechanical Properties of the Fluvioglacial Deposits of Belarus as Ground Strata

The article presents the information of particular conditions of formation and physicomechanical properties of fluvioglacial deposits of Belarus. Deposits mineral and petrographic composition found to be similar to those in moraine formations, because they were formed as result of erosion of the moraine material by thawing glacial streams. They comprises of the large variety of granulometric types from gravel-pebble to sandy loam with the predominance of sands. They are characterized by significant lateral and depth variability. In general, fluvioglacial soils have the acceptable geotechnical properties and may serve as a good base for different engineering constructions of any class of responsibility

Complex interplay between 3d and 4f magnetic systems and magnetic chirality in multiferroic Dy1−x_{1-x}Hox_xMnO3_3 (x=0,0.2x = 0, 0.2)

Structural, magnetic and multiferroic properties of single crystals of Dy$_{1-x}$Ho$_x$MnO$_3$ ($x = 0, 0.2$) were investigated by the different methods of polarized and classical neutron diffraction and macroscopic methods in order to determine the effect of Ho doping on the magneto-electric behavior of the title compounds. It is shown that substitution by Ho of 20% on the position of Dy do not change overall crystal symmetry of compound. It remains of Pnma type for both compositions down to the very low temperatures. Magnetic ordering do not change the crystal structure. Precise magnetic order and it detailed temperature and field evolution both in the pristine and substituted compounds we determined using single crystal neutron diffraction and magnetization measurements. The results show a complex interplay between transition metal and rear earth magnetic sub lattices leading to so-called "Mn-controlled" and "Dy-controlled" magnetic states. Using polarized neutron diffraction 3D character of rear earth magnetic order in Dy$_{0.8}$Ho$_{0.2}$MnO$_3$ in contract to DyMnO$_3$ and occurrence of the chiral type magnetic structure on Mn subsystem could be revealed. The influence of the external electric field on the magnetic chirality could be directly evidenced, proving strong magneto-electric coupling in multiferroic phase. The study of the electric polarization under similar temperatures and fields on the same samples provides the direct correlation between the results of the microscopic and macroscopic investigations.Comment: 26 pages, 12 figures, 3 table

Complex interplay between 3d and 4f magnetic systems in multiferroic DyMnO3_3

Structural and magnetic properties of single crystals of DyMnO$_3$ were investigated by neutron diffraction in order to study the peculiarities of $3d$-$4f$ interactions in this compound. Precise magnetic order and its detailed temperature evolution were determined using single crystal neutron diffraction. Elliptical cycloid on manganese subsystem below $T_{Ch}$ = 19 K was confirmed, with temperature decrease the elipticity of the Mn magnetic structure reduces significantly, creating almost circular cycloid. Temperature evolution of the magnetic structure demonstrate specific hysteretic behavior. The results show a complex interplay between transition metal and rare earth magnetic sublattices leading to so-called “Mn- controlled” and “Dy- controlled” magnetic states. The strong and complicate $3d$-$4f$ interaction leads to the unusual very slow magnetic structure relaxation