81 resultados para Gaussian scale mixture

em Doria (National Library of Finland DSpace Services) - National Library of Finland, Finland


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In the present work, liquid-solid flow in industrial scale is modeled using the commercial software of Computational Fluid Dynamics (CFD) ANSYS Fluent 14.5. In literature, there are few studies on liquid-solid flow in industrial scale, but any information about the particular case with modified geometry cannot be found. The aim of this thesis is to describe the strengths and weaknesses of the multiphase models, when a large-scale application is studied within liquid-solid flow, including the boundary-layer characteristics. The results indicate that the selection of the most appropriate multiphase model depends on the flow regime. Thus, careful estimations of the flow regime are recommended to be done before modeling. The computational tool is developed for this purpose during this thesis. The homogeneous multiphase model is valid only for homogeneous suspension, the discrete phase model (DPM) is recommended for homogeneous and heterogeneous suspension where pipe Froude number is greater than 1.0, while the mixture and Eulerian models are able to predict also flow regimes, where pipe Froude number is smaller than 1.0 and particles tend to settle. With increasing material density ratio and decreasing pipe Froude number, the Eulerian model gives the most accurate results, because it does not include simplifications in Navier-Stokes equations like the other models. In addition, the results indicate that the potential location of erosion in the pipe depends on material density ratio. Possible sedimentation of particles can cause erosion and increase pressure drop as well. In the pipe bend, especially secondary flows, perpendicular to the main flow, affect the location of erosion.

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Object detection is a fundamental task of computer vision that is utilized as a core part in a number of industrial and scientific applications, for example, in robotics, where objects need to be correctly detected and localized prior to being grasped and manipulated. Existing object detectors vary in (i) the amount of supervision they need for training, (ii) the type of a learning method adopted (generative or discriminative) and (iii) the amount of spatial information used in the object model (model-free, using no spatial information in the object model, or model-based, with the explicit spatial model of an object). Although some existing methods report good performance in the detection of certain objects, the results tend to be application specific and no universal method has been found that clearly outperforms all others in all areas. This work proposes a novel generative part-based object detector. The generative learning procedure of the developed method allows learning from positive examples only. The detector is based on finding semantically meaningful parts of the object (i.e. a part detector) that can provide additional information to object location, for example, pose. The object class model, i.e. the appearance of the object parts and their spatial variance, constellation, is explicitly modelled in a fully probabilistic manner. The appearance is based on bio-inspired complex-valued Gabor features that are transformed to part probabilities by an unsupervised Gaussian Mixture Model (GMM). The proposed novel randomized GMM enables learning from only a few training examples. The probabilistic spatial model of the part configurations is constructed with a mixture of 2D Gaussians. The appearance of the parts of the object is learned in an object canonical space that removes geometric variations from the part appearance model. Robustness to pose variations is achieved by object pose quantization, which is more efficient than previously used scale and orientation shifts in the Gabor feature space. Performance of the resulting generative object detector is characterized by high recall with low precision, i.e. the generative detector produces large number of false positive detections. Thus a discriminative classifier is used to prune false positive candidate detections produced by the generative detector improving its precision while keeping high recall. Using only a small number of positive examples, the developed object detector performs comparably to state-of-the-art discriminative methods.

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The purpose of the study is: (1) to describe how nursing students' experienced their clinical learning environment and the supervision given by staff nurses working in hospital settings; and (2) to develop and test an evaluation scale of Clinical Learning Environment and Supervision (CLES). The study has been carried out in different phases. The pilot study (n=163) explored the association between the characteristics of a ward and its evaluation as a learning environment by students. The second version of research instrument (which was developed by the results of this pilot study) were tested by an expert panel (n=9 nurse teachers) and test-retest group formed by student nurses (n=38). After this evaluative phase, the CLES was formed as the basic research instrument for this study and it was tested with the Finnish main sample (n=416). In this phase, a concurrent validity instrument (Dunn & Burnett 1995) was used to confirm the validation process of CLES. The international comparative study was made by comparing the Finnish main sample with a British sample (n=142). The international comparative study was necessary for two reasons. In the instrument developing process, there is a need to test the new instrument in some other nursing culture. Other reason for comparative international study is the reflecting the impact of open employment markets in the European Union (EU) on the need to evaluate and to integrate EU health care educational systems. The results showed that the individualised supervision system is the most used supervision model and the supervisory relationship with personal mentor is the most meaningful single element of supervision evaluated by nursing students. The ward atmosphere and the management style of ward manager are the most important environmental factors of the clinical ward. The study integrates two theoretical elements - learning environment and supervision - in developing a preliminary theoretical model. The comparative international study showed that, Finnish students were more satisfied and evaluated their clinical placements and supervision with higher scores than students in the United Kingdom (UK). The difference between groups was statistical highly significant (p= 0.000). In the UK, clinical placements were longer but students met their nurse teachers less frequently than students in Finland. Arrangements for supervision were similar. This research process has produced the evaluation scale (CLES), which can be used in research and quality assessments of clinical learning environment and supervision in Finland and in the UK. CLES consists of 27 items and it is sub-divided into five sub-dimensions. Cronbach's alpha coefficient varied from high 0.94 to marginal 0.73. CLES is a compact evaluation scale and user-friendliness makes it suitable for continuing evaluation.

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Opinnäytetyön tarkoituksena oli kuvata alle 1 500 gramman painoisena syntyneiden keskoslasten motorista kehitystä kolmen, kuuden ja kahdentoista kuukauden korjatussa iässä, sekä tuoda esille mahdollisia motorisen kehityksen yhteisiä piirteitä Alberta Infant Motor Scale (AIMS) -testistöllä arvioituna. Työ toteutettiin yhteistyössä Lasten ja nuorten sairauksien toimialan fysioterapian yksikön kanssa, jossa keskoslasten motorisen kehityksen arviointi AIMS-testistöllä oli toteutettu vuosina 2005 - 2006. Idea opinnäytetyöhön syntyi yhteisten keskusteluiden pohjalta fysioterapeuttien kanssa. Opinnäytetyön tavoitteena oli analysoida ja koota yhteenveto Lasten ja nuorten sairauksien toimialalle heidän tutkimastaan aineistosta. Työ oli luonteeltaan kuvaileva kvantitatiivinen tutkimus valmiiksi saadun aineiston pohjalta. Aineisto koostui yhteensä 109 keskoslapsen AIMS-testistön arviointilomakkeista. Keskoslapsista 54 oli kolmen kuukauden, 42 kuuden kuukauden ja 13 kahdentoista kuukauden korjatussa iässä. Tulokset analysoitiin käyttämällä SPSS 13.0 Windows Release-tilasto-ohjelmaa ja tulokset esitettiin taulukoiden ja kuvioiden avulla. Tiedonkeruumenetelminä käytimme kirjallisuuden lisäksi uusimpia tutkimusartikkeleita sekä asiantuntijahaastattelua. Kolmen kuukauden ikäisistä keskoslapsista 51 sijoittui AIMS-testistön motorista kehitystä kuvaaville käyrille. Kolme lasta jäi käyrien alapuolelle. Kuuden kuukauden ikäisten keskoslasten kokonaispistemäärissä oli enemmän hajontaa. 15 lasta jäi AIMS-testistön motorista kehitystä kuvaavien käyrien alapuolelle. Kahdentoista kuukauden ikäisistä lapsista yhdeksän sijoittui motorista kehitystä kuvaaville käyrille ja neljä lasta jäi käyrien alapuolelle. Yhteisenä piirteenä kaikilta kolmen kuukauden ikäisiltä ja 14 kuuden kuukauden ikäiseltä lapselta puuttui taito tukeutua yläraajoihin istuma-asennossa (Sitting With Propped Arms). Tutkimustulosten perusteella kolmen kuukauden ikäisten keskoslasten motorinen kehitys oli valtaosalla (51/54) ikätasoista. Kuuden ja kahdentoista kuukauden ikäisten keskoslasten motorisessa kehityksessä yksilölliset erot olivat suurempia. Tutkimusjoukkomme keskoslapsista motorinen kehitys oli ikätasoa heikompaa 22 keskoslapsella. Lasten ja nuorten sairauksien toimiala saa käyttöönsä työmme tulokset, joita voidaan hyödyntää keskoslasten motorisen kehityksen seurannassa sekä fysioterapian kehittämisessä. Työmme lisää AIMS-testistön tunnettavuutta ja siitä on myös laajemmin hyötyä lasten parissa työskenteleville fysioterapeuteille.

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Selostus: Kationi-anionitasapaino ummessaolevien lypsylehmien säilörehuruokinnassa kalsiumin saannin ollessa runsas

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Selostus: Kationi-anionitasapaino ja kalsiumin saanti ummessaolevien lypsylehmien säilörehuruokinnassa

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Selostus: Kationi-anionitasapaino ja magnesiumin saanti ummessaolevien lypsylehmien säilörehuruokinnassa