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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.
51

Expansão da soja no cerrado maranhense: uma análise da influência antrópica no clima regional.

NOGUEIRA, Virgínia de Fátima Bezerra. 14 May 2018 (has links)
Submitted by Emanuel Varela Cardoso (emanuel.varela@ufcg.edu.br) on 2018-05-14T19:52:45Z No. of bitstreams: 1 VIRGÍNIA DE FÁTIMA BEZERRA NOGUEIRA – TESE (PPGMET) 2015.pdf: 2294664 bytes, checksum: 660de8adf5292855bb29d8690566ac6b (MD5) / Made available in DSpace on 2018-05-14T19:52:45Z (GMT). No. of bitstreams: 1 VIRGÍNIA DE FÁTIMA BEZERRA NOGUEIRA – TESE (PPGMET) 2015.pdf: 2294664 bytes, checksum: 660de8adf5292855bb29d8690566ac6b (MD5) Previous issue date: 2015-02-27 / A avaliação das conexões entre degradação ambiental no bioma Cerrado e mudanças climáticas constitui o foco central desta pesquisa. Nos últimos anos a intervenção humana em biomas ricos em biodiversidade, que é de grande importância para o país, aumentou consideravelmente provocando alterações significativas no ciclo hidrológico. O impacto dessas intervenções exige a realização de pesquisas com abordagens mais específicas, que permitam aprimorar o conhecimento sobre os impactos de influências antrópicas no clima regional e evidenciar a urgência de medidas mitigadoras. Os procedimentos de análise se basearam na caracterização ambiental da área através de informações de satélite (sensoriamento remoto), e detecção de mudanças no padrão de comportamento de variáveis atmosféricas resultantes da transformação da vegetação nativa em áreas agrícolas (monocultura da soja) na região de Chapadinha-MA. Técnicas estatísticas, incluindo análise multivariada (análise fatorial em análise de componentes principais) e testes paramétricos (teste – t, teste F / análise de variância) e não paramétricos (teste Sequencial de Mann-Kendall / teste de Pettitt), foram usadas como principais ferramentas de investigação. Os resultados indicam que o processo de degradação da vegetação nativa (Cerrado) na região de Chapadinha teve início antes da entrada da soja; no entanto, a sojicultora foi determinante para tornar significativa este impacto no clima. Evidências de impacto de mudanças antrópicas foram detectadas nas temperaturas máxima e mínima. O aumento significativo nos valores das temperaturas extremas é um indício importante de que a degradação no Cerrado pode contribuir no processo de desertificação na região analisada. / The evaluation of the connections between environmental degradation in the Cerrado biome and climate change is the central focus of this research. In recent years human intervention in biomes rich in biodiversity, which is of great importance for the country has risen sharply causing significant changes in the hydrological cycle. The impact of these interventions requires conducting research with more specific approaches, which allow improve knowledge about the impacts of anthropogenic influences on regional climate and highlight the urgent need for mitigation measures. Screening procedures were based on environmental characterization of the area through satellite information (remote sensing), and detection of changes in the pattern of behavior of atmospheric variables resulting from the processing of native vegetation in agricultural areas (Soy monoculture) in the Chapadinha region -MA. Statistical techniques, including multivariate analysis (factor analysis in principal component analysis) and parametric tests (t - test, test F / ANOVA) and nonparametric (Sequential Mann-Kendall / Pettitt test) were used as main research tools. The results indicate that the native vegetation degradation process (cerrado) in the region Chapadinha started before soybean input; however, the sojicultora was crucial to make this significant impact on the climate. Impact evidence of anthropogenic changes were detected in maximum and minimum temperatures. The significant increase in extremes of temperature values is an important indication that the degradation in the Cerrado can contribute to the process of desertification in the region analyzed.
52

Žemių sausinimo įtaka Mūšos upės hidrologimiam režimui / Impact of Land Drainage on Musa River Hydrological Regime

Norvydaitė, Laura 16 June 2010 (has links)
Šlapių žemių sausinimo įtaka nuotėkiui Lietuvoje vertinama nevienareikšmiškai. Darbe analizuojama Mūšos upės ties Ustukiais hidrologinės charakteristikos ir žemių sausinimo šioje baseino dalyje įtaka upės nuotėkiui. Darbui atlikti panaudoti 1960 – 2006 metų paros nuotėkio, metinio kritulių kiekio, vidutinės paros oro temperatūros duomenys ir nusausintų plotų apimtys. Sudarytas kritulių įtakos debitui grafikas, kuris parodo, kad šie rodikliai glaudžiai susiję. Nagrinėjami du laikotarpiai 1960-1981 metai iki patvenkiant Mūšos upę, ir 1983-2006 metai po Dvariukų tvenkinio įrengimo. Naudojant DHRAM programinę įrangą, išskirtos ir analizuotos 33 debito charakteristikos. Naudojant Mano–Kendalio testą nustatyti 33-jų hidrologinių charakteristikų kaitos trendai. Tyrimas parodė, kad žemių sausinimas didelės įtakos Mūšos upės nuotėkio pokyčiams nepadarė. Sausinimo poveikis pasireiškia maksimalių debitų sumažėjimu ir paros debitų pokyčiais. / Wet soil drainage on the runoff Lithuania controversial. The paper analyzes the beating of the river at Ustukiai hydrological characteristics and soil drainage in the basin of the river runoff influence. Used to carry out the 1960 - 2006 years of daily runoff, rainfall, average daily air temperature data and the volume of drained areas. Made in rainfall affect the flow graph, which shows that these indicators are closely related. Study of two periods of 1960-1981 years before damming Mūša river, and the 1983-2006 year Dvariukų pond construction. Using DHRAM software identified and analyzed the 33 characteristics of flow. Using Mann-Kendall test to determine their 33-hydrological characteristics of the change in trend. The study showed that the draining of lands affected by high river runoff beating did not change. The drainage effect of maximal decrease in discharges and daily discharges change.
53

Analys av flyttmönster i Norrköpings kommun / Analysis of migration patterns in the municipality of Norrköping

Järvstråt, Lotta January 2011 (has links)
The objective of this Bachelor thesis is to analyze moving patterns in Norrköping’s municipality. The main aim is to analyze the migration to, from, and within the municipality of Norrköping, not only for the population as a whole but also for groups of special interest. Another aim is to compare migration patterns in Norrköping with those of other municipalities in Sweden.Several data sets have been used, each of them extracted from population statistics carried out by Statistics Sweden (SCB).Data mining using association analysis is used for finding the migration pattern within Norrköping’s municipality and several questions are examined using descriptive statistics. Mann-Kendall tests are used to determine interesting trends in the population changes.The results show that pre-school children do not remain longer in the city centre than they did previously; people moving to Norrköping from within Sweden move mostly to the city centre, though immigrants from abroad mainly favour Hageby and Åby tätort. Furthermore, the results show that people generally move to areas that are geographically similar to where they were or have been before. There is a decrease in migration of people with a Humanities or Arts background, as there is for those with a pedagogy and teacher training background. Areas with a decrease in migration are the suburbs as well as built-up areas at the fringe of the municipality. Norrköping has both lower immigration and emigration than other comparable Swedish municipalities. / Syftet med denna kandidatuppsats är att analysera flyttmönster i Norrköpings kommun. Målet är att analysera både flyttningar till, från, och inom Norrköpings kommun för dels hela populationen och dels speciellt intressanta grupper. Ett annat mål är att jämföra flyttmönster i Norrköping med några andra kommuner i Sverige.För att kunna genomföra dessa analyser har flera datamaterial använts. Gemensamt för datamaterialen är att de allihop baseras på Statistiska Centralbyråns (SCB:s) befolkningsstatistik.För att hitta mönster för hur människor flyttar inom Norrköpings kommun används associationsanalys. Med hjälp av deskriptiv analys undersöks olika särskilt intressanta områden av omflyttningarna i kommunen. Vidare används Mann-Kendalltester för att se om det finns några särskilt intressanta trender i befolkningsutvecklingen.Resultatet visar att ingen förändring har skett när det gäller ifall barn i förskoleåldern bor kvar i stadskärnan i större utsträckning än tidigare. Inflyttare från Sverige flyttar i stor utsträckning till stadskärnan, medan Hageby och Åby tätort är vanliga att flytta till om man flyttar från utlandet. Vidare visar resultatet att människor oftast flyttar till geografiskt nära områden samt områden som har ungefär samma bostadsform som det man tidigare bott i. Flyttningsnettot är negativt för de med utbildning inom Humaniora och konst samt Pedagogik och lärarutbildning. De områden som har negativ befolkningsutveckling ligger i utkanten av centralorten eller är tätorter i utkanten av kommunen. Norrköpings kommun har lägre inflyttning och utflyttning än de flesta andra jämförbara kommuner.
54

Coding Techniques for Error Correction and Rewriting in Flash Memories

Mohammed, Shoeb Ahmed 2010 August 1900 (has links)
Flash memories have become the main type of non-volatile memories. They are widely used in mobile, embedded and mass-storage devices. Flash memories store data in floating-gate cells, where the amount of charge stored in cells – called cell levels – is used to represent data. To reduce the level of any cell, a whole cell block (about 106 cells) must be erased together and then reprogrammed. This operation, called block erasure, is very costly and brings significant challenges to cell programming and rewriting of data. To address these challenges, rank modulation and rewriting codes have been proposed for reliably storing and modifying data. However, for these new schemes, many problems still remain open. In this work, we study error-correcting rank-modulation codes and rewriting codes for flash memories. For the rank modulation scheme, we study a family of one- error-correcting codes, and present efficient encoding and decoding algorithms. For rewriting, we study a family of linear write-once memory (WOM) codes, and present an effective algorithm for rewriting using the codes. We analyze the performance of our solutions for both schemes.
55

From membership to fellowship

Bland, James C. January 1986 (has links)
Thesis (D. Min.)--Westminster Theological Seminary, Philadelphia, 1986. / Includes bibliographical references (leaves 167-187).
56

Analýza koncentrací živin ve vodách a jejich odnosů z vybraného povodí / Analysis of nutrients concentrations in waters and their transport from selected catchment

JIRKOVSKÁ, Veronika January 2014 (has links)
The aim of this study was to analyze the presence of the trend of long-term time series of concentrations and losses of nutrients and their descriptions. The concentrations of nitrogen and phosphorus compounds were evaluated. The analysis was performed on selected catchment of large, medium and small areas. All observed catchment are located in the basin of dam Švihov. Trends were tested using non parametric methods - Mann-Kendall test, Seasonal Mann-Kendall test and Kendall's correlation coefficient . In this study there are generally described monitored cycles of nutrients, nitrogen and phosphorous. There are also characterized the factors, which effect leaching of these nutrients to water (from the catchment). The paper also outlines the progression of water quality in the Czech Republic, which was influenced by political and economic changes in Europe in the second half of the 20th century.
57

An?lise da variabilidade clim?tica sobre a produtividade da soja no munic?pio de Bom Jesus (PI) / Analysis of climatic variability on the soybean productivity in Bom Jesus (PI)

Reis, Layara Campelo dos 13 November 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-23T22:05:00Z No. of bitstreams: 1 LayaraCampeloDosReis_DISSERT.pdf: 2271838 bytes, checksum: c4d28430acbd6f35763abf08b3d4b899 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-29T18:30:11Z (GMT) No. of bitstreams: 1 LayaraCampeloDosReis_DISSERT.pdf: 2271838 bytes, checksum: c4d28430acbd6f35763abf08b3d4b899 (MD5) / Made available in DSpace on 2016-06-29T18:30:11Z (GMT). No. of bitstreams: 1 LayaraCampeloDosReis_DISSERT.pdf: 2271838 bytes, checksum: c4d28430acbd6f35763abf08b3d4b899 (MD5) Previous issue date: 2015-11-13 / Nos ?ltimos anos o munic?pio de Bom Jesus (PI) passou a figurar como uma regi?o de grande potencial para produ??o de soja (Glycine max (L.) Merrill) em larga escala. Esta cultura agr?cola ganha espa?o nos cerrados bonjesuenses apresentando, no decorrer dos anos, crescimento exponencial de ?reas cultivadas. Entretanto, a produtividade n?o acompanha esse mesmo ritmo de crescimento, passando por per?odos de oscila??es, ainda que exista dispon?vel um grande suporte de tecnologias, materiais gen?ticos de maior potencial produtivo, uso de t?cnicas de manejo e corre??o do solo e da crescente qualifica??o dos produtores rurais. Portanto, no presente estudo, considerou-se que as condi??es clim?ticas exercem uma a??o limitante ?s m?ximas produtividades de soja neste munic?pio. Diante desse contexto, a pesquisa visa analisar poss?veis tend?ncias em vari?veis meteorol?gicas que possam influenciar na produtividade da soja no munic?pio de Bom Jesus. Para tanto utilizaram-se diferentes conjuntos de dados meteorol?gicos: i) dados di?rios de dois per?odos (1984-2014) e (1974-2014), ambos obtidos a partir do banco de dados do Instituto Nacional de Meteorologia (INMET); ii) Normais Climatol?gicas do Brasil de 1961-1990 do INMET; iii) dados de produ??o agr?cola municipal da cultura da soja dos anos/safras de 1997/1998 a 2012/2013 obtidos no banco de dados de Produ??o Agr?cola Municipal (PAM) do Instituto Brasileiro de Geografia e Estat?stica (IBGE). Nas an?lises foram realizados c?lculos para o c?mputo das Normais Climatol?gicas (1984-2014) e aplica??es estat?sticas. Dentre os m?todos estat?sticos foram realizados: i) o teste de Wilcoxon - pareado para avaliar as diferen?as entre as climatologias dos per?odos de 1961-90 e 1984-14; ii) o teste de tend?ncia (Mann-Kendall), no intuito de analisar a tend?ncia de varia??o dos dados agrometeorol?gicos (precipita??o, temperatura m?xima, temperatura m?nima e amplitude diurna da temperatura - DTR); iii) an?lise multivariada (an?lise de Cluster) pelo m?todo de Ward e o teste de correla??o de Spearman (rs), para identificar a rela??o entre os dados agrometeorol?gicos e dados de variabilidade anual da produtividade da soja. Para a aplica??o dos testes o estudo adotou n?vel de signific?ncia estat?stica de 5%. Os resultados apresentados indicam que a sazonalidade da climatologia de 1984-2014 apresentou mudan?as com rela??o ? climatologia passada em todas as vari?veis analisadas, exceto na insola??o e na precipita??o. Quanto ? variabilidade dos elementos agrometeorol?gicos, observaram-se tend?ncia negativa significativa para a precipita??o no m?s de outubro e positiva significativa no m?s de dezembro, as quais constatam altera??es nos padr?es do clima local, demonstrado pelo atraso da retomada do per?odo chuvoso, que poder? ser considerado na condu??o de medidas de planejamento para a defini??o da ?poca de semeadura do cultivo da soja. Foi poss?vel identificar tamb?m tend?ncias positivas com signific?ncias estat?sticas, na temperatura m?xima, para todos os meses que fazem parte do ciclo da soja (novembro - abril), que por sua vez tender? a provocar efeitos adversos sobre a fisiologia da cultura, e consequentemente impactos no rendimento final. Notou-se uma correla??o positiva significativa entre a produtividade de soja e a precipita??o no m?s de mar?o, apontando que per?odos de estiagens neste m?s s?o prejudiciais para o desenvolvimento da cultura da soja. Quanto ? correla??o entre as vari?veis (temperatura m?xima, m?nima e DTR) e a variabilidade anual da produtividade da soja, o resultado do teste n?o mostrou correla??o com signific?ncia estat?stica para o per?odo analisado, visto que considerando a faixa recomendada para o desenvolvimento do cultivo, estas vari?veis clim?ticas n?o s?o fatores limitantes na produtividade final da soja no munic?pio de Bom Jesus (PI). Assim, espera-se que este estudo possa contribuir para a proposi??o de medidas estrat?gias de planejamento, que levam em conta o papel da variabilidade clim?tica sobre a produtividade final da cultura da soja. / The climate is still main responsible for the variations soybean productivity (Glycine max (L.) Merrill), exerting a limiting action on these agricultural systems. The bomjesuense cerrado, this culture has proved, over the years, an increase of cultivated areas, however, productivity does not keep the same pace, going through periods of oscillations. Thus, although the crop is added to high technology, culture has great vulnerability to climatic adversities. Thus, the present study aims to analyze possible trends in meteorological variables, which can influence the soybean yield in Bom Jesus. For this purpose, different datasets were used, as follows: i) two periods of daily data (1984-2014 and 1974-2014), both obtained from the National Meteorological Institute (INMET); ii) climate normals from 1961-1990 as defined by INMET; iii) local agricultural production data of soybean-year (1997/1998 to 2012/2013) obtained from the Municipal Agricultural Production (PAM) dataset, which is management by Brazilian Institute of Geography and Statistics (IBGE). The analysis procedures included calculations of climate normals for 1984 to 2014 period and some statistical applications, as follows: i) the Wilcoxon test, used to evaluate differences between climate normals (1961 to 1990 and 1984 to 2014); ii) the Mann-Kendall nonparametric test, in order to analyze the linear trend of agrometeorological variables (rainfall, maximum temperature, minimum temperature and diurnal range of temperature; iii) cluster analysis by Ward method and the Spearman correlation test (rs) to identify the relationship between agrometeorological variable and soybean annual productivity. We adopted a statistical significance level of 5%. The results indicate changes in seasonality of the 1984-2014 climatology with respect to past climatology for all variables analyzed, except for insolation and precipitation. However, the monthly analysis of precipitation indicate negative trend during October and positive trend in December, causing a delay in start of rainy season. If this trend is persistent this result must be considered in futures definitions of the soybean crop sowing date over the region studied. With Mann-Kendall test was possible to identify positive trends with statistical significance in maximum temperature for all month forming part of soybean cycle (from November to April), which in turn tends to cause adverse effects on crop physiology, and consequently impacts on the final yield. Was identified a significant positive correlation between soybean yield and precipitation observed in March, thus precipitation deficit in this month is harmful to the soybean crop development. No statistically significant correlation was identified among maximum temperature, minimum temperature, and DTR with annual soybean productivity due these range of meteorological variables are not limiting factors in the final soybean yield in Bom Jesus (PI). It is expected that this study will contribute to propose planning strategies considering the role of climate variability on soybean crop final yield.
58

Méthodes d'apprentissage statistique pour le ranking théorie, algorithmes et applications

Robbiano, Sylvain 19 June 2013 (has links) (PDF)
Le ranking multipartite est un problème d'apprentissage statistique qui consiste à ordonner les observations qui appartiennent à un espace de grande dimension dans le même ordre que les labels, de sorte que les observations avec le label le plus élevé apparaissent en haut de la liste. Cette thèse vise à comprendre la nature probabiliste du problème de ranking multipartite afin d'obtenir des garanties théoriques pour les algorithmes de ranking. Dans ce cadre, la sortie d'un algorithme de ranking prend la forme d'une fonction de scoring, une fonction qui envoie l'espace des observations sur la droite réelle et l'ordre final est construit en utilisant l'ordre induit par la droite réelle. Les contributions de ce manuscrit sont les suivantes : d'abord, nous nous concentrons sur la caractérisation des solutions optimales de ranking multipartite. Une nouvelle condition sur les rapports de vraisemblance est introduite et jugée nécessaire et suffisante pour rendre le problème de ranking multipartite bien posé. Ensuite, nous examinons les critères pour évaluer la fonction de scoring et on propose d'utiliser une généralisation de la courbe ROC nommée la surface ROC pour cela ainsi que le volume induit par cette surface. Pour être utilisée dans les applications, la contrepartie empirique de la surface ROC est étudiée et les résultats sur sa consistance sont établis. Le deuxième thème de recherche est la conception d'algorithmes pour produire des fonctions de scoring. La première procédure est basée sur l'agrégation des fonctions de scoring apprises sur des sous-problèmes de ranking binaire. Dans le but d'agréger les ordres induits par les fonctions de scoring, nous utilisons une approche métrique basée sur le de Kendall pour trouver une fonction de scoring médiane. La deuxième procédure est une méthode récursive, inspirée par l'algorithme TreeRank qui peut être considéré comme une version pondérée de CART. Une simple modification est proposée pour obtenir une approximation de la surface ROC optimale en utilisant une fonction de scoring constante par morceaux. Ces procédures sont comparées aux algorithmes de l'état de l'art pour le ranking multipartite en utilisant des jeux de données réelles et simulées. Les performances mettent en évidence les cas où nos procédures sont bien adaptées, en particulier lorsque la dimension de l'espace des caractéristiques est beaucoup plus grand que le nombre d'étiquettes. Enfin, nous revenons au problème de ranking binaire afin d'établir des vitesses minimax adaptatives de convergence. Ces vitesses sont montrées pour des classes de distributions contrôlées par la complexité de la distribution a posteriori et une condition de faible bruit. La procédure qui permet d'atteindre ces taux est basée sur des estimateurs de type plug-in de la distribution a posteriori et une méthode d'agrégation utilisant des poids exponentiels.
59

Změny srážko-odtokového režimu v oblasti Šumavy / Changes of rainfall-runoff regime in the Šumava /Bohemian Forest region

Fiala, Ondřej January 2015 (has links)
CHANGES OF RAINFALL-RUNOFF REGIME IN THE ŠUMAVA / BOHEMIAN FOREST REGION Abstract: The goal of this thesis is the evaluation of changes in rainfall-runoff regime in the Šumava region from time and spacial point of view. The thesis includes research and applied part. The research part is dedicated to the methods of evaluation of runoff changes and their possible causes in the Šumava region. In the applied part there is an analysis of precipitaion - runoff regime for long-term time series of average annual and monthly discharges and also annual and monthly precipitations for selected gauging stations in Czech, German and Austrian part of Šumava using absolute and relative homogenity tests and Mann - Kendall test for long-term trend. One of the main aims of this thesis is the identification of possible orographical effect or the difference between windward and leeward part of Šumava. In conclusion the achieved results are evaluated, discussed and compared with subject publications. Key words: absolute homogenity, Mann - Kendall test, runoff, discharge, relative homogenity, precipitation, trend, Šumava, changes
60

Změny podílu pevných a kapalných srážek v chladném půlroce a jejich vliv na jarní odtok z vybraných horských povodí / Changes in snowfall fraction in cold season and their impact on spring runoff in selected mountain catchments

Blšťák, Adam January 2018 (has links)
The precipitation falling as rain or snow has different impact on regional water resources and their annual distribution. Shift from solid to liquid form of precipitation following the increase of the surface air temperatures could be important because such change could influence the timing of spring runoff and cause water scarcity in summer. In this study, the spatial and temporal variations of ratio of snowfall to total precipitation (Sf), mean air temperature, day of year of melt-out and winter and spring runoff is analysed. Data were examined for 11 meteorological and 6 hydrological stations in the mountains catchment in Czechia for November-April 1965-2014. Data were analyzed using the Mann-Kendall trend test. Major results show that Sf has been decreasing strongly throughout the whole examined area, with the strongest decrease in the foothill area of the northern mountains of Czechia. Stronger decrease is observed in lower elevations, at the stations with meant air temperature close to melt temperature. Strongest decrease was observed in March and the weakest decrease was observed in December and April, The significant decreases in Sf are associated with large increase in mean winter air temperatures. Due to the increasing mean air temperature in the cold season, the total rainfall is...

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