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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
451

Análises fatorial e de componentes principais aplicadas ao estudo dos fatores influenciadores de processos erosivos /

Pascoto, Tamara Vieira. January 2020 (has links)
Orientador: Anna Silvia Palcheco Peixoto / Resumo: A erosão é um problema ambiental em que a perda de solo pode acarretar problemas econômicos e, quando próximos a urbanizações, problemas sociais. A cidade de São Manuel está situada no interior de São Paulo e apresenta, tanto solos argilosos com baixa suscetibilidade a erosão, como solos arenosos com alta suscetibilidade a erosão. Uma vez que existem áreas suscetíveis à erosão próximas à área urbana capazes de colocar a população em risco, surgiu a necessidade de analisá-las a fim de auxiliar políticas públicas para minimizar suas consequências. Com isso, a presente pesquisa propôs o desenvolvimento de uma metodologia para gerar índices de erosão, por Análise de Componente Principal (PCA) e por Análise Fatorial, fundamentado em alguns dos principais fatores influenciadores nos processos erosivos que ocorrem na área urbana do município. Nessa etapa foram considerados: textura do solo; declividade; permeabilidade; uso e ocupação; pluviosidade; e erodibilidade dos solos. Inicialmente, foram levantadas as feições erosivas existentes na área urbana, espacializadas e classificadas. Entre as 9 feições espacializadas, duas eram provenientes de processos fluviais, duas estavam recuperadas, restando cinco feições erosivas lineares para serem estudadas. Uma das cinco, apesar de estar estabilizada, apresentou um avanço significativo em um dos braços. Das feições estudadas, apenas uma foi classificada como ravina, sendo as demais classificadas como voçorocas. Após levantados os fatores in... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Erosion is an environmental problem where soil loss can lead either to economic problems or, whether close to urbanization, social problems. São Manuel town is located in the interior of São Paulo and has both clayey soils with low susceptibility to erosion and sandy soils with high susceptibility to erosion. Since there are areas susceptible to erosion close to the urban area capable of putting the population at risk, the need arose to analyze them in order to assist public policies to minimize their consequences. Therefore, this research proposed the development of a methodology to generate erosion indexes, by Principal Component Analysis (PCA) and Factorial Analysis, based on some of the main factors influencing erosion processes that occur in the urban area of the municipality. At this stage the following factors were considered: soil texture; slope; permeability; use and occupation; rainfall; and soil erodibility. Initially, the erosive features existing in the urban area were surveyed, spatialized and classified. Among the 9 spatialized features, two were from fluvial processes, two were recovered, leaving five linear erosive features to be studied. One of the five, despite being stabilized, presented a significant advance in one of the arms. Of the studied features, only one was classified as ravine, the others being classified as gullies. After surveyed the influencing factors, they were evaluated according to two methodologies: Method A - it was based on the analysis... (Complete abstract click electronic access below) / Mestre
452

Metabolomic comparison of selected Helichrysum species to predict their antiviral properties

Heyman, Heino Martin 23 July 2010 (has links)
From the Helichrysum genus 600 species occur in Africa of which 244 species are found in South Africa. The most commonly used Helichrysum species for medicinal purposes are H. cymosum, H. odoratissimum, H. petiolare and H. nudifolium. The medicinal uses include the treatment of coughs, colds, fever, infection, headaches, menstrual pain and are very popular for wound dressing. Previous published research has shown that H. aureonitens has antiviral properties against Herpes simplex virus type 1 (HSV-1). In this study, further investigation into the Helichrysum species was undertaken, to establish the active constituents responsible for anti-HSV activity using a metabolomics approach. The cytotoxicity of 12 Helichrysum species was investigated and ranged from <3.125 μg/ml to 277.8 μg/ml on the vero cell line. The 12 Helichrysum species also showed various levels of antiviral activity against HSV, with both the water-methanol and chloroform extracts of H. adenocarpum subsp. adenocarpum being the most active extract at 25 μg/ml. In this study the activity of Helichrysum species against HIV-1 RT was also investigated. Helichrysum populifolium was the most active extract, inhibiting the HIV-1 RT enzyme by 63.78 % at 200 μg/ml. The bioactivity data and the spectral nuclear magnetic resonance (NMR) data of al the Helichrysum species from this study was analysed using the SIMCA-P software to discriminate between the different species on the basis of their bioactivity and chemical composition. The samples did not group well on Principal Component Analysis (PCA) but did separate well using the Orthogonal Projection to Latent Structure – Discriminate Analysis (OPLS-DA) on the basis of their activity and NMR spectra data. From the OPLS scoring plots analysis, contribution plots were created which indicated regions responsible for the difference between the species, with these regions being investigated to identify the bioactive constituents. It was thus possible to use metabolomics to discriminate between samples on the basis of their activity and show that it could probably be used in future as a tool to identify active ingredients in medicinal plants and accelerate drug discovery. Copyright / Dissertation (MSc)--University of Pretoria, 2009. / Plant Science / unrestricted
453

Multi-Location Field Evaluation of Bambara Groundnut (Vigna Subterranean (L) Verdc) for Agronomic Performance and Seed Protein.

Mogale, Tlou Elizabeth 18 May 2018 (has links)
MSCAGR (Plant Production) / Department of Plant Production / Bambara groundnut (Vigna subterranea) is one of the most important legumes cultivated primarily for food by smallholder farmers in Africa. It is an affordable source of protein and contributes to income generation as well as soil fertility. Despite its importance, it is cultivated largely for subsistence purposes in South Africa. Growers use landraces. The agronomic performance of the traditional varieties depends on environmental factors prevailing in a particular area. In Limpopo and Mpumalanga Provinces, there is no adequate information regarding the performance of bambara groundnut germplasm. The objectives of the study were to (i) determine the agronomic performance of Bambara groundnut across three contrasting locations in Limpopo and Mpumalanga provinces over two cropping seasons (ii) determine the genotypic variation in the seed protein level among 42 bambara groundnut genotypes. Forty-two bambara groundnut genotypes were evaluated under three different environmental conditions (Syferkuil, Thohoyandou and Nelspruit) over two (2013/2014, 2014/2015) seasons in a 7 × 6 rectangular lattice design replicated three times. Eight agronomic traits including dry shoot weight (DSW), number of pods per plant (NPP), pod length (PL), number of seed per pod (NSP), pod weight per plant (PWT), seed weight per plant (SWT), 100 seed weight (100-SWT) and seed yield (SYLD) were measured. The results showed that there were significant genotype x location interactions which demonstrated that the prevailing agro-ecological conditions at the test locations were distinct from each other. Five genotypes (‘BGN-19‘, ‘BGN-11‘, ‘BGN-12‘, ‘BGN-4‘and ‘BGN-34‘) attained >25.0% seed yield advantage over the local check ‘BGN-39‘. The results also showed that light brown coloured genotypes attained relatively higher seed yield compared to the other seed colours types. The cultivar superiority index (CSI) showed that three genotypes (‘BGN-12‘, ‘BGN-19’ and ‘BGN-34’) were the most stable across the test locations and attained >900.0 kg/ha on average. There were significantly high positive correlations between PWT and each of the three other attributes (SWT, 100 SWT and SYLD). In terms of seed protein, the results showed a poor relationship between seed yield and protein levels. ‘BGN-12’ which produced the highest seed yield, attained the lowest percent seed protein while genotype. On average, the genotypes contained 21.72% protein. The highest and lowest seed protein quantities were attained by the genotypes ‘BGN-42’ (25.17%) and ‘BGN-12’ (19.89%) respectively. / NRF
454

Pohlavní dimorfismus tvaru incisura ischiadica major pánevní kosti člověka. / Shape sexual dimorphism of the greater sciatic notch on human hip bone.

Nehasilová, Lenka January 2011 (has links)
The aim of this work is sexual dimorphism quantification of greater sciatic notch profile using 2D geometric morphometrics methods. The curvature was digitized by two different methods - manually with contact digitizer MicroScribe G2 and automatically with software Morphome3cs. Results from each method were comparised and advatages and disadvantages of boths methods were discussed. Target sample of 114 adult specimens of known sex was analyzed. This collection comes from Maxwell Museum of Anthropology, The University of New Mexico, Albuquerque and contains 57 male and 57 female hip bones. For the method verification the test smaple contains 112 adult specimens of known sex was used. This collection comes from Universidad Nacional Autonóma de México (UNAM). This collection contains 56 male and 56 female hip bones. The procrustes analysis, principal components analysis, thin plate spine and discriminant function analysis were used for analysis. We could make a detail description of morphologic differences in greater sciatic notch shape of men and women because of shape visualisation and difference of both group was confirmed by discriminant function analysis. Sex assesment achieves accuracy 92,11% - 98,25% in dependence on used methods and number of semilandmarks.
455

Analýza školních vzdělávacích programů přírodopisu na druhém stupni základních škol / Analysis of school education programmes of natural science for lower secondary education

Roreitnerová, Daniela January 2020 (has links)
8 Abstract About fifteen years ago, the Czech education system underwent a curricular reform. Thanks to that, schools have gained more freedom, but also responsibility how education will look in their case. The implementation of the reform was accompanied by various expectations but also by misunderstandings and problems. A revision of Framework Education Programme (FEP) is now planned. At the moment, however, it is not yet clear what will be the subject or the goals of this revision. This work aims to examine the current situation in the field of natural science and to subject selected school educational programs (SEP) to quantitative analysis. SEPs are understood here as one of the possible indicators of how some ideas from the Framework Educational Programs for Lower Education were conceived and developed by teachers. The thesis focuses mainly on areas that have been newly accentuated by the curricular reform. These are topics of key competences, interconnection of subjects (either within cross-curricular topics or interdisciplinary links through selected curriculum) and last but not least the topic of methods and forms of teaching and work with the content itself. All online SEPs of Prague lower secondary schools (plus ten unpublished on the school websites) were analyzed, taking into account only the...
456

Genetic and biological architecture of pork quality, carcass, primal-cut and growth traits in Duroc pigs

Hannah E Willson (9187739) 01 August 2020 (has links)
<p>Within the last few decades, swine breeding programs have been refined to include pork quality and novel carcass traits alongside growth, feed efficiency, and carcass leanness in the selection programs for terminal sire lines with a goal to produce high quality and efficient pork product for consumers. In order to accurately select for multiple traits at once, it becomes imperative to explore their genetic and biological architecture. The genetic architecture of traits can be explored through the estimation of genetic parameters, genome-wide association studies (GWAS), gene networks and metabolic pathways. An alternative approach to explore the genetic and biological connection between traits is based on principal component analysis (PCA), which generates novel “pseudo-phenotypes” and biological types (biotypes). In this context, the main objective of this thesis was to understand the genetic and biological relationship between three growth, eight conventional carcass, 10 pork quality, and 18 novel carcass traits included in two studies. The phenotypic data set included 2,583 records from female Duroc pigs from a terminal sire line. The pedigree file contained 193,764 animals and the genotype file included 21,344 animals with 35,651 single nucleotide polymorphisms (SNPs). The results of the first study indicate that genetic progress can be achieved for all 39 traits. In general, the heritability estimates were moderate, while most genetic correlations were generally moderate to high and favorable. Some antagonisms were observed but those genetic correlations were low to moderate in nature. Thus, these relationships can be considered when developing selection indexes. The second study showed that there are strong links between traits through their principal components (PCs). The main PCs identified are linked to biotypes related to growth, muscle and fat deposition, pork color, and body composition. The PCs were also used as pseudo-phenotypes in the GWAS analysis, which identified important candidate genes and metabolic pathways linked to each biotype. All of this evidence links valuable variables such as belly, color, marbling, and leanness traits. Our findings greatly contribute to the optimization of genetic and genomic selection for the inclusion of valuable and novel traits to improve productive efficiency, novel carcass, and meat quality traits in terminal sire lines.<br></p><p></p>
457

Optimering av lagernivåer vid distributionscentralen Bygg Ole / Optimization of inventory levels at the distribution central of Bygg Ole

Göransson, Gustav, Johnson, Mathias January 2016 (has links)
Detta examensarbetes syfte var att undersöka möjligheter till förbättring av hantering av lagernivåer för Bygg Ole Saltsjö-Boo. En kombination av aspekter från både systemteknik och industriell ekonomi har använts. I rapporten applicerades Guaranteed Service-Level modellen baserad på historisk försäljning i kombination relevanta teorier om lagerkostnad. Rapporten var begränsad till att behandla utvalda produkter med hög omsättning från två utvalda leverantörer till Bygg Ole. Efterfrågan för alla produkter i rapporten utom en är icke säsongsberoende. Särskild hänsyn har dessutom tagits till servicenivå, kapitalkostnader och variation i efterfråga. Resultatet gav att en implementering av modellen skulle ge lägre lagernivåer och därmed lägre lagerkostnader. Slutsatsen från rapporten var att modellen skulle kunna implementeras, eventuellt med höga administrativa kostnader i början. Bygg Ole har också en möjlighet att använda ett ordersystem baserat på den matematiska GSL-modellen (Guaranteed Service-Level) i kombination med prognoser över efterfrågan producerade av försäljningsavdelningen på Bygg Ole. Detta skulle potentiellt kunna öka precisionen i lagerhanteringen. Den nuvarande lagerräntan är relativt lågt bestämd och därför minskas de beräknade besparingarna från implementering av modellen. Om lagerräntan skulle vara högre skulle den ekonomiska fördelen med implementeringen vara tydligare. Rekommendationen till Bygg Ole är att tillämpa den rekommenderade GSL-modellen i kombination med ett system för prognos över efterfrågan på några utvalda produkter och sedan utvärdera resultatet. / The aim of this thesis was to examine possible improvements in the inventory management and procedure of ordering at Bygg Ole Saltsjö-Boo. A combination of aspects from both Systems Engineering and Industrial Engineering and Management has been used. In the report, a Guaranteed Service-Level model based on historical data of sales in combination with relevant theories about inventory carrying cost has been applied. The study was limited to specific chosen products with high sales from two selected suppliers of Bygg Ole. All these products in the study except one experienced low seasonal variety in demand. Furthermore special consideration was taken to service level, cost of capital and variability of demand. The result was that an implementation of the model would yield lower inventory levels and therefore lower carrying costs of inventory. The conclusion from the report was that the model could be implemented, although with possibly high administrative costs in the beginning. Bygg Ole also has a possibility of using an ordering system based on the mathematical GSL-model (Guaranteed Service-Level) in combination with forecasts of demand conducted by the sales department of Bygg Ole. This could potentially increase precision in the inventory management. The current inventory carrying charge is compounded relatively low and therefore decreases the calculated savings from implementing the model. If the carrying charge would be higher, the benefits of implementation would be more evident. The recommendation for Bygg Ole is to apply the recommended GSL-model in combination with a demand forecast planning system on a few selected products and then evaluate the result.
458

Classify part of day and snow on the load of timber stacks : A comparative study between partitional clustering and competitive learning

Nordqvist, My January 2021 (has links)
In today's society, companies are trying to find ways to utilize all the data they have, which considers valuable information and insights to make better decisions. This includes data used to keeping track of timber that flows between forest and industry. The growth of Artificial Intelligence (AI) and Machine Learning (ML) has enabled the development of ML modes to automate the measurements of timber on timber trucks, based on images. However, to improve the results there is a need to be able to get information from unlabeled images in order to decide weather and lighting conditions. The objective of this study is to perform an extensive for classifying unlabeled images in the categories, daylight, darkness, and snow on the load. A comparative study between partitional clustering and competitive learning is conducted to investigate which method gives the best results in terms of different clustering performance metrics. It also examines how dimensionality reduction affects the outcome. The algorithms K-means and Kohonen Self-Organizing Map (SOM) are selected for the clustering. Each model is investigated according to the number of clusters, size of dataset, clustering time, clustering performance, and manual samples from each cluster. The results indicate a noticeable clustering performance discrepancy between the algorithms concerning the number of clusters, dataset size, and manual samples. The use of dimensionality reduction led to shorter clustering time but slightly worse clustering performance. The evaluation results further show that the clustering time of Kohonen SOM is significantly higher than that of K-means.
459

Regional assessment of trends in vegetation change dynamics using principal component analysis

Osunmadewa, Babatunde A., Csaplovics, E., R. A., Majdaldin, Aralova, D., Adeofun, C. O. 30 August 2019 (has links)
Vegetation forms the basis for the existence of animal and human. Due to changes in climate and human perturbation, most of the natural vegetation of the world has undergone some form of transformation both in composition and structure. Increased anthropogenic activities over the last decades had pose serious threat on the natural vegetation in Nigeria, many vegetated areas are either transformed to other land use such as deforestation for agricultural purpose or completely lost due to indiscriminate removal of trees for charcoal, fuelwood and timber production. This study therefore aims at examining the rate of change in vegetation cover, the degree of change and the application of Principal Component Analysis (PCA) in the dry sub-humid region of Nigeria using Normalized Difference Vegetation Index (NDVI) data spanning from 1983-2011. The method used for the analysis is the T-mode orientation approach also known as standardized PCA, while trends are examined using ordinary least square, median trend (Theil-Sen) and monotonic trend. The result of the trend analysis shows both positive and negative trend in vegetation change dynamics over the 29 years period examined. Five components were used for the Principal Component Analysis. The results of the first component explains about 98 % of the total variance of the vegetation (NDVI) while components 2-5 have lower variance percentage (< 1%). Two ancillary land use land cover data of 2000 and 2009 from European Space Agency (ESA) were used to further explain changes observed in the Normalized Difference Vegetation Index. The result of the land use data shows changes in land use pattern which can be attributed to anthropogenic activities such as cutting of trees for charcoal production, fuelwood and agricultural practices. The result of this study shows the ability of remote sensing data for monitoring vegetation change in the dry-sub humid region of Nigeria.
460

Assessment of Water Quality of Four Mahoning River Sub-Watersheds, Northeast Ohio

Alam, Sohaib 18 March 2022 (has links)
No description available.

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