Development of Educational Ontology for C-Programming

Development of educational ontologies is a step towards creation of sharable and reusable adaptive educational systems. Ontology as a conceptual courseware structure may work as a mind tool for effective teaching and as a visual navigation interface to the learning objects. The paper discusses an approach to the practical ontology development and presents the designed ontology for teaching/learning C programming

Diagrammatic expansions of Hubbard models

Optical lattice are periodic structures made of light, they are formed by the interference of laser beams producing standing waves. The depth and the periodicity of the optical lattice can be highly controlled, therefore, optical lattices provide an ideal framework to study quantum effects. In this project we used diagrammatic techniques to obtain a quasi particle description of an interacting system of electrons in an optical lattice in the basis of Hubbard model

Effects of fish manipulation on the plankton community in small hypertrophic lakes from the Pampa Plain (Argentina)

AbstractTrophic cascade hypotheses predict that fish will affect the structure and biomass of pelagic plankton communities. In order to investigate trophic cascade effects from fish down to phytoplankton, whole-lake studies were performed in five hypertrophic (mean total phosphorus (TP) concentrations higher than 1000mgm−3) shallow lakes located in the Pampa Plain. The main climatic characteristic of this region is the alternation between periods of drought and flood, with corresponding changes of lake depth and conductivity of lake water. All lakes were studied from April to December 2000. Samples were taken of their physical and chemical characteristics and biotic communities, focusing on the zooplankton community. Fish were manipulated in four lakes (Capurro, Longinotti, Vedia 1, Vedia 2), while the fifth (Lake Vedia 3) was left undisturbed as a reference system. High abundance of planktivorous minnows (Jenynsia multidentata and Cheirodon interruptus) dominated the fish community in the reference lake. In the manipulated lakes, fish stocks were largely reduced in late autumn (May). During winter, Capurro, Longinotti and Vedia 1 were stocked with a visual planktivore, the pampean silverside (Odontesthes bonariensis, Atherinidae). Fish stocking was 24, 33 and 19kgha−1, respectively. In contrast, no fish were stocked in Lake Vedia 2. Following fish removal, large Daphnia appeared in these lakes and grazed intensively on the phytoplankton. In contrast, no Daphnia were found in the reference lake (Vedia 3). The stocking of O. bonariensis in lakes Capurro, Longinotti and Vedia 1 led to a decrease in the percentage of large cladocerans and a rise in the phytoplankton biomass:TP ratio. Moreover, the lakes mentioned were stocked with different quantities of silversides over different periods of time. These differences were reflected temporarily in the plankton dynamics, affecting mainly larger sized zooplankton. Nevertheless, the presence of Daphnia was short lived in the lake where fish had been removed and no O. bonariensis were stocked. Competition for resources and recruitment of remaining fish probably caused a collapse in the zooplankton biomass. Our results support the idea that fish predation on zooplankton and its effect on phytoplankton is very intense in small pampean lakes. Fish removal was short lived, however. This could be because in small pampean lakes fish recolonization is favored, and minnows are highly prolific. Moreover, if manipulation of the trophic structure of lakes is undertaken in the pampean region, high nutrient loading from the watershed, climate and hydrology should also be taken into account

Evaluation of topic-based adaptation and student modeling in QuizGuide

This paper presents an in-depth analysis of a nonconventional topic-based personalization approach for adaptive educational systems (AES) that we have explored for a number of years in the context of university programming courses. With this approach both student modeling and adaptation are based on coarse-grained knowledge units that we called topics. Our motivation for the topic-based personalization was to enhance AES transparency for both teachers and students by utilizing typical topic-based course structures as the foundation for designing all aspects of an AES from the domain model to the end-user interface. We illustrate the details of the topic-based personalization technology, with the help of the Web-based educational service QuizGuide—the first system to implement it. QuizGuide applies the topic-based personalization to guide students to the right learning material in the context of an undergraduate C programming course. While having a number of architectural and practical advantages, the suggested coarse-grained personalization approach deviates from the common practices toward knowledge modeling in AES. Therefore, we believe that several aspects of QuizGuide required a detailed evaluation—from modeling accuracy to the effectiveness of adaptation. The paper discusses how this new student modeling approach can be evaluated, and presents our attempts to evaluate it from multiple different prospects. The evaluation of QuizGuide across several consecutive semesters demonstrates that, although topics do not always support precise user modeling, they can provide a basis for successful personalization in AESs

Omnidirectional Horizontally Polarized UHF Antenna Design

For calibration of circular phased arrays, a highly omnidirectional horizontally polarized UHF antenna was required. Commercially available antennas are not omnidirectional enough for this application. In this project we compared several potential designs including an electrically small loop, curved crossed dipoles and n-petal wheel. 5-petal wheels had the best simulated performance so we then optimized it and built a prototype. The prototype was measured to be omnidirectional within +/- 0.4 dB. Detailed suggestions were made for further improving the design

Slide Lock Design Process Development

A process for the design of slide lock mechanisms for Central Industrial Supply was developed. The process incorporated tools from several theoretical design processes. The developed design process was tested using a case study, in which a self-closing mechanism was designed using the developed process. The case study proved the process to be effective, with the designed mechanism satisfying all requirements by 100% or more. Highlighted weaknesses of the process were afterwards corrected

Research and simulation of images classification algorithm for distributed objects obtained by remote sensing of the Earth's surface

Application of ultra-wideband signals and large apertures makes it possible to obtain a sufficiently detailed radar image of a spatially distributed object at the processing unit output. But the problem of optimal classification of synthetic aperture radar (SAR) data remains relevant due to specific features of radar images. The paper describes solution of the synthesis problem for optimal SAR image classification algorithm. The optimal set of very informative and small dimension features is found and features based on the moments of SAR images are proposed. A comparative analysis of classification algorithms using various features is made, and the ratio is proposed, which can be used as the classification sign that is invariant to object shift and to specific distortions caused by the object rotation. © 2016 Academic Publications, Ltd

Simulating intracellular calcium dynamics

Calcium concentration in the myocytes is crucial in cardiac excitation-contraction coupling (the conversion of an electrical stimulus to a mechanical contraction of the heart cells). This part of the intricate process can be studied by simulating the calcium dynamics. In this project we consider a model that combines stochastic transitions among different states of channels and deterministic calcium dynamics and perform some computer simulations employing MATLAB. Then, we examine whether the model makes correspondence with empirical results taken from the Cellular Physiology Laboratory of the Cardiovascular Research Center (CSIC-ICCC)2014/201