7 resultados para Strongly Regular Graph
em Doria (National Library of Finland DSpace Services) - National Library of Finland, Finland
Resumo:
Tiivistelmä
Resumo:
Magnetic field dependencies of Hall coefficient and magnetoresistivity are investigated in classical and quantizing magnetic fields in p-Bi2Te3 crystals heavily doped with Sn grown by Czochralsky method. Magnetic field was parallel to the trigonal axis C3. Shubnikov-de Haas effect and quantum oscillations of the Hall coefficient were measured at temperatures 4.2 K and 11 K. On the basis of the magnetic field dependence of the Hall coefficient a method of estimation of the Hall factor and Hall mobility using the Drabble- Wolf six ellipsoid model is proposed. Shubnikov-de Haas effect and quantum oscillations of the Hall coefficient were observed at 4.2 K and 11 K. New evidence for the existence of the narrow band of Sn impurity states was shown. This band is partly filled by electrons and it is overlapping with the valence states of the light holes. Parameters of the impurity states, their energy ESn - 15 meV, band broadening ¿<< k0T and localization radius of the impuritystate R - 30 Å were obtained.
Resumo:
The use of domain-specific languages (DSLs) has been proposed as an approach to cost-e ectively develop families of software systems in a restricted application domain. Domain-specific languages in combination with the accumulated knowledge and experience of previous implementations, can in turn be used to generate new applications with unique sets of requirements. For this reason, DSLs are considered to be an important approach for software reuse. However, the toolset supporting a particular domain-specific language is also domain-specific and is per definition not reusable. Therefore, creating and maintaining a DSL requires additional resources that could be even larger than the savings associated with using them. As a solution, di erent tool frameworks have been proposed to simplify and reduce the cost of developments of DSLs. Developers of tool support for DSLs need to instantiate, customize or configure the framework for a particular DSL. There are di erent approaches for this. An approach is to use an application programming interface (API) and to extend the basic framework using an imperative programming language. An example of a tools which is based on this approach is Eclipse GEF. Another approach is to configure the framework using declarative languages that are independent of the underlying framework implementation. We believe this second approach can bring important benefits as this brings focus to specifying what should the tool be like instead of writing a program specifying how the tool achieves this functionality. In this thesis we explore this second approach. We use graph transformation as the basic approach to customize a domain-specific modeling (DSM) tool framework. The contributions of this thesis includes a comparison of di erent approaches for defining, representing and interchanging software modeling languages and models and a tool architecture for an open domain-specific modeling framework that e ciently integrates several model transformation components and visual editors. We also present several specific algorithms and tool components for DSM framework. These include an approach for graph query based on region operators and the star operator and an approach for reconciling models and diagrams after executing model transformation programs. We exemplify our approach with two case studies MICAS and EFCO. In these studies we show how our experimental modeling tool framework has been used to define tool environments for domain-specific languages.
Resumo:
The amount of biological data has grown exponentially in recent decades. Modern biotechnologies, such as microarrays and next-generation sequencing, are capable to produce massive amounts of biomedical data in a single experiment. As the amount of the data is rapidly growing there is an urgent need for reliable computational methods for analyzing and visualizing it. This thesis addresses this need by studying how to efficiently and reliably analyze and visualize high-dimensional data, especially that obtained from gene expression microarray experiments. First, we will study the ways to improve the quality of microarray data by replacing (imputing) the missing data entries with the estimated values for these entries. Missing value imputation is a method which is commonly used to make the original incomplete data complete, thus making it easier to be analyzed with statistical and computational methods. Our novel approach was to use curated external biological information as a guide for the missing value imputation. Secondly, we studied the effect of missing value imputation on the downstream data analysis methods like clustering. We compared multiple recent imputation algorithms against 8 publicly available microarray data sets. It was observed that the missing value imputation indeed is a rational way to improve the quality of biological data. The research revealed differences between the clustering results obtained with different imputation methods. On most data sets, the simple and fast k-NN imputation was good enough, but there were also needs for more advanced imputation methods, such as Bayesian Principal Component Algorithm (BPCA). Finally, we studied the visualization of biological network data. Biological interaction networks are examples of the outcome of multiple biological experiments such as using the gene microarray techniques. Such networks are typically very large and highly connected, thus there is a need for fast algorithms for producing visually pleasant layouts. A computationally efficient way to produce layouts of large biological interaction networks was developed. The algorithm uses multilevel optimization within the regular force directed graph layout algorithm.
Resumo:
Tämän pro gradu -tutkimuksen tavoitteena oli tutkia osaamisen johtamisen käytäntöjä ja kehittämistarpeita kohdeorganisaatiossa henkilöstön näkökulmasta. Tutkimuksen tarkoituksena oli selvittää, miten tehtyjä henkilöstötutkimuksia on hyödynnetty kohdeorganisaatiossa ja näkyykö tämä hyödyntäminen käytännön johtamisessa henkilöstön mielestä. Tutkimus suoritettiin laadullisena tapaustutkimuksena ja empiirinen aineisto kerättiin kuudella teemahaastattelulla, jotka analysoitiin sisällönanalyysimenetelmällä. Tutkimuksessa kartoitettiin, millaisia osaamisen johtamisen käytäntöjä kohdeorganisaatiossa on. Tutkimuksen tuloksien perusteella osaamisen johtamisen peruselementit ovat olemassa: säännölliset palaverit koettiin tärkeiksi, mutta koulutuksien ja kehityskeskusteluiden järjestämisessä sekä jälkiseurannassa henkilöstö näki parannettavaa. Myös hiljaisen tiedon siirtäminen ja hyödyntäminen koettiin merkittäväksi tekijäksi organisaation onnistuneen toiminnan ja jatkuvuuden kannalta. Tutkimuksessa todettiin osaamisen johtamisen kehittämisen ja osaamisen kehittämisen menetelmien linkittyvän vahvasti toisiinsa ja tutkimuksen tuloksena esitettiin konkreettisia toimenpide-ehdotuksia osaamisen johtamisen kehittämisestä kohdeorganisaation johdolle. Tutkimuksen mukaan osaamisen johtaminen ja henkilöstöjohtaminen sulautuvat toisiinsa, eikä niitä voida tarkastella erikseen. Johdon ja henkilöstön välisellä vuorovaikutuksella on suuri merkitys onnistuneelle osaamisen johtamiselle. Keskeistä on kytkeä osaamisen johtaminen organisaation käytäntöihin ja varata sen implementointiin riittävästi resursseja.
Resumo:
The number of persons with visual impairment in Tanzania is estimated to over 1.6 million. About half a million of these persons are children aged 7-13. Only about 1% of these children are enrolled in schools. The special schools and units are too few and in most cases they are far away from the children’s homes. More and more regular schools are enrolling children with visual impairment, but the schools lack financial resources, tactile teaching materials and trained special education teachers. Children with visual impairment enrolled in regular schools seldom get enough support and often fail in examinations. The general aim of this study was to contribute to increased knowledge and understanding about how teachers can change their teaching practices and thus facilitate the learning of children with visual impairment included in regular classrooms as they participate in an action research project. The project was conducted in a primary school in a poor rural region with a high frequency of blindness and visual impairment. The school was poorly resourced and the average number of pupils per class was 90. The teachers who participated in the collaborative action research project were the 14 teachers who taught blind or visually impaired pupils in grades 4 and 6, in total 6 pupils. The action research project was conducted during a period of 6 months and was carried out in five cycles. The teachers were actively involved in all the project activities; identifying challenges, planning solutions, producing teaching materials, reflecting on outcomes, collaborating and evaluating. Empirical data was collected with questionnaires, interviews, observations and focus group discussions. The findings of the study show that the teachers managed to change their teaching practices through systematic reflection, analysis and collaboration. The teachers produced a variety of tactile teaching materials, which facilitated the learning of the pupils with visual impairment. The pupils learned better and felt more included in the regular classes. The teachers gained new knowledge and skills. They grew professionally and started to collaborate with each other. The study contributes to new knowledge of how collaborative action research can be conducted in the area of special education in a Tanzanian school context. The study has also relevance to the planning of school-based professional development programs and teacher education programs in Tanzania and in other low-income countries. The results also point at strategies which can promote inclusion of children with disabilities in regular schools.