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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.
71

Bird Migration Echoes Observed by Polarimetric Radar

NAKAMURA, Kenji, SATOH, Shinsuke, FURUZAWA, Fumie A., MINDA, Haruya 01 June 2008 (has links)
No description available.
72

Savaiminio žėlimo intensyvumas plynų kirtimų biržėse Šiaulių urėdijoje / The intensity of regeneration in the clear-cut areas Šiauliai forest enterprise

Vaitekūnas, Simonas 14 January 2009 (has links)
Šiame darbe buvo įvertinta žėlimui paliktų plyno kirtimo biržių jaunuolynų formavimosi priklausomybė nuo motininio medyno rūšinės sudėties. Tyrimo tikslas: Ištirti savaiminio žėlimo intensyvumą ir žėlinių rūšinę sudėtį, priklausomai nuo augavietės ir motininio medyno rūšinės sudėties. Tyrimo uždaviniai: Ištirti savaiminio žėlimo intensyvumą ir jo eigą 5 metų plyno kirtimo biržėse Šiaulių miškų urėdijoje priklausomai nuo augavietės. Ištirti žėlinių rūšinę sudėtį ir jos kitimą, priklausomai nuo motininio medyno rūšinės sudėties. Tyrimo objektas: VĮ „Šiaulių miškų urėdijos“ miškai Iš urėdijos plynų kirtimų registracijos knygų išrinktos 302 2000 -2004 m. plyno kirtimo kirtavietės ir sudarytas jų sąrašas. Detalesni tyrimai atlikti 14 biržių, jose išskirti tyrimo bareliai. Tyrimo metodai: Pagal 1995 m. ir 2006 m. miškotvarkos medžiagą pateikiama buvusio motininio medyno ir augančių jaunuolynų taksacinė charakteristika, bei analizuojama jaunuolyno rūšinės sudėties priklausomybė nuo augavietės tipo ir motininio medyno rūšinės sudėties. Detalesni tyrimai buvo atliekami remiantis lauko tyrimais atsienojant laikinas tyrimo aikšteles. Tyrimo rezultatai: Tyrimo eigoje nustatyta, kad motininio medyno rūšinė sudėtis turi didžiausią įtaką savaiminiam žėlimui ir atsikūrusio miško rūšinei sudėčiai. Beržynai formuojasi, kai motininio medyno rūšinėje sudėtyje, buvo 1 dalis beržo ir greta auga derantys beržynai. Juodalksnio jaunuolynas susiformuoja, kai motininio medyno sudėtyje 5 ir daugiau... [toliau žr. visą tekstą] / The aim of present study was to evaluate relationship of young self-generating stand from previous generation stand after clear cut. The object of this study is situated in Šiauliai forest enterprise forest stands. Also there were clear-cutting registration papers and forest inventory of year 1995-2006 analyzed in this study. It was found that bigger area is after clear-cutting for self generating and species composition of previous generation stand has the main influence to self generating and species composition of new self generating stand.
73

Acoustic and Articulatory Changes Accompanying Different Speaking Instructions and Listening Situations

Goy, HuiWen 12 February 2010 (has links)
The purpose of this study was to compare the effects on speech acoustics of a wide variety of speaking instructions that have been used across different studies on clear speech, and to investigate the acoustic and articulatory changes that occur in response to these instructions and in different talking environments. Five young adult females were recorded speaking under different instructions meant to elicit more intelligible speech, and measures of speaking rate, speaking F0 and intensity were found to distinguish instructions to speak "as if to someone with hearing loss" from instructions to speak "clearly" or "slowly", which produced different results from instructions to speak "loudly" or as if in noise. Preliminary acoustic and articulatory data are described for a sixth talker who spoke under a subset of these instructions, and in both a quiet and a noisy talking environment.
74

Acoustic and Articulatory Changes Accompanying Different Speaking Instructions and Listening Situations

Goy, HuiWen 12 February 2010 (has links)
The purpose of this study was to compare the effects on speech acoustics of a wide variety of speaking instructions that have been used across different studies on clear speech, and to investigate the acoustic and articulatory changes that occur in response to these instructions and in different talking environments. Five young adult females were recorded speaking under different instructions meant to elicit more intelligible speech, and measures of speaking rate, speaking F0 and intensity were found to distinguish instructions to speak "as if to someone with hearing loss" from instructions to speak "clearly" or "slowly", which produced different results from instructions to speak "loudly" or as if in noise. Preliminary acoustic and articulatory data are described for a sixth talker who spoke under a subset of these instructions, and in both a quiet and a noisy talking environment.
75

Definitions of Clear-sky Fluxes and Implications

Verma, Abhishek 2011 December 1900 (has links)
Clear-sky top-of-atmosphere (TOA) fluxes are important in estimating the impact of clouds on our climate. In this study, we quantitatively compare the clear-sky fluxes measurements of the Clouds and the Earths Radiant Energy System (CERES) instrument to clear-sky fluxes from two reanalysis, NASA's Modern Era Retrospective-analysis for Research and Application (MERRA), and the European Center for Medium Range Weather Forecast Interim reanalysis (ERA-Interim). In the first comparison, we compare observed fluxes from individual cloud-free field-of- views to the reanalyses. In the second comparison, we compare monthly averaged observed clear-sky fluxes to those from the reanalyses. Monthly clear-sky fluxes are calculated by averaging fluxes from cloud-free regions. In both comparisons, the fluxes generally agree within +/- 10 W/m^2. Finally, we show that, while the differences between the fluxes of observations and the reanalyses are several W/m2, the inter-annual anomalies agree much better, with zonal and global average inter-annual anomalies typically agreeing within 1 W/m^2. The longwave clear-sky anomalies show excellent agreement even when comparing individual grid points, whereas the shortwave clear-sky anomalies are generally smaller at individual grid points.
76

Defining the roles of autophagy in ovarian carcinoma

Spowart, Jaeline E. 17 July 2012 (has links)
Ovarian cancer is a significant concern for women’s health as it is the most lethal of all gynaecological malignancies. One of the reasons for the high mortality of this disease is that traditionally used chemotherapeutic treatments tend to have poor initial or sustained efficacy against ovarian tumours. Resistance to such treatments may in part be mediated by autophagy, a cell survival process in which unnecessary or damaged components of the cytoplasm are engulfed within a double-membraned vesicle known as an autophagosome and ultimately degraded upon fusion of the autophagosome with a lysosome. Autophagy has been shown to be employed by cells to aid in their survival under stresses such as nutrient deprivation, hypoxia, chemotherapy treatment, and growth factor withdrawal. As these stresses are commonly encountered by ovarian cancer cells, it is possible that autophagy promotes ovarian cancer cell survival. This thesis aims to investigate which stimuli induce autophagy in ovarian cancer cells and whether or not this induction can promote cell survival. In addition, there is a particular focus on the comparison of autophagy utilization between subtypes of ovarian cancer, as the subtypes are in fact considered different diseases and may vary in their usage of autophagy. The first chapter of this thesis provides relevant background information on autophagy as well as ovarian cancer and its subtypes. In the second chapter, I describe studies in which tumours from a large cohort of patients with ovarian cancer are assessed for LC3A, a marker of autophagy, in addition to markers of other cellular processes including hypoxia. Here I found that LC3A was significantly associated with poor patient survival in patients with the clear cell subtype of ovarian cancer, but not other subtypes. I also found that LC3A expression was associated with markers of hypoxia in the clear cell patient tumours and that clear cell carcinoma cell lines preferentially induced autophagy in response to hypoxia in vitro as compared to cell lines of the high-grade serous subtype. These results indicate that clear cell ovarian tumours are uniquely dependent upon autophagy in response to hypoxia. In the third chapter, I investigated the autophagic response to treatment with the standard ovarian cancer chemotherapy drugs carboplatin and paclitaxel in a syngeneic mouse model of ovarian cancer. I found that these drugs did indeed induce autophagy and that the cancer cells utilized autophagy to promote resistance to these chemotherapeutics. In addition, when the tumour cells were grown in syngeneic mice, treatment with the autophagy inhibitor hydroxychloroquine resulted in a significant suppression of tumour growth. Together, my findings indicate that further investigation into the use of autophagy inhibitors in ovarian cancer patients is warranted and that different specific rational drug combinations for each subtype will likely yield optimal results. / Graduate
77

Semantics, implementation and pragmatics of Clear, a program specification language

Sannella, Donald Theodore January 1982 (has links)
Specifications are necessary for communicating decisions and intentions and for documenting results at many stages of the program development process. Informal specifications are typically used today, but they are imprecise and often ambiguous. Formal specifications are precise and exact but are more difficult to write and understand. We present work aimed toward enabling the practical use of formal specifications in program development, concentrating on the Clear language for structured algebraic specification. Two different but equivalent denotational semantics for Clear are given. One is a version of a semantics due to Burstall and Goguen with a few corrections, in which the category-theoretic notion of a colimit is used to define Clear's structuring operations independently of the underlying 'institution' (logical formalism). The other semantics defines the same operations by means of straightforward set-theoretic constructions; it is not institutionindependent but it can be modified to handle all institutions of apparent interest. Both versions of the semantics have been implemented. The settheoretic implementation is by far the more useful of the two, and includes a parser and typechecker. An implementation is useful for detecting syntax and type errors in specifications, and can be used as a front end for systems which manipulate specifications. Several large specifications which have been processed by the set-theoretic implementation are presented. A semi-automatic theorem prover for Clear built on top of the Edinburgh LCF system is described. It takes advantage of the structure of Clear specifications to restrict the available information to that which seems relevant to proving the theorem at hand. If the system is unable to prove a theorem automatically the user can attempt the proof interactively using the high-level primitives and inference rules provided. We lay a theoretical foundation for the use of Clear in systematic program development by investigating a new notion of the implementation of a specification by a lower-level specification. This notion extends to handle parameterised specifications. We show that this implementation relation is transitive and commutes with Clear's structuring operations under certain conditions. This means that a large specification can be refined to a program in a gradual and modular fashion, where the correctness of the individual refinements guarantees the correctness of the resulting program.
78

Aspects of heterogeneity : effects of clear-cutting and post-harvest extraction of bioenergy on plants in boreal forests /

Åström, Marcus, January 2006 (has links)
Diss. (sammanfattning) Umeå : Umeå universitet, 2006. / Härtill 4 uppsatser.
79

Um estudo de limpeza em base de dados desbalanceada e com sobreposição de classes

Machado, Emerson Lopes 04 1900 (has links)
Dissertação (mestrado)—Universidade de Brasília, Instituto de Ciências Exatas, Departamento de Ciência da Computação, 2007. / Submitted by Luis Felipe Souza (luis_felas@globo.com) on 2008-12-10T18:56:04Z No. of bitstreams: 1 Dissertacao_2007_EmersonMachado.pdf: 480909 bytes, checksum: 33454d8cde13ccd0274df91f48a4125d (MD5) / Approved for entry into archive by Georgia Fernandes(georgia@bce.unb.br) on 2009-03-04T12:18:48Z (GMT) No. of bitstreams: 1 Dissertacao_2007_EmersonMachado.pdf: 480909 bytes, checksum: 33454d8cde13ccd0274df91f48a4125d (MD5) / Made available in DSpace on 2009-03-04T12:18:48Z (GMT). No. of bitstreams: 1 Dissertacao_2007_EmersonMachado.pdf: 480909 bytes, checksum: 33454d8cde13ccd0274df91f48a4125d (MD5) / O objetivo geral desta pesquisa é analisar técnicas para aumentar a acurácia de classificadores construídos a partir de bases de dados desbalanceadas. Uma base de dados é desbalanceada quando possui muito mais casos de uma classe do que das outras, portanto possui classes raras. O desbalanceamento também pode ser em uma mesma classe se a distribuição dos valores dos atributos for muito assimétrica, levando à ocorrência de casos raros. Algoritmos classificadores são muito sensíveis a estes tipos de desbalanceamentos e tendem a valorizar as classes (ou casos) predominantes e a ignorar as classes (ou casos) de menor freqüência. Modelos gerados para bases de dados com classes raras apresentam baixa acurácia para estas classes, o que é problemático quando elas são classes de interesse (ou quando uma delas é a classe de interesse). Já os casos raros podem ser ignorados pelos algoritmos classificadores, o que é problemático quando tais casos pertencem à classe (ou às classes) de interesse. Uma nova proposição de algoritmo é o Cluster-based Smote, que se baseia na combinação dos métodos de Cluster-based Oversampling (oversampling por replicação de casos guiada por clusters) e no SMOTE (oversampling por geração de casos sintéticos). O método Cluster-based Oversampling visa melhorar a aprendizagem de pequenos disjuntos, geralmente relacionados a casos raros, mas causa overfitting do modelo ao conjunto de treinamento. O método SMOTE gera novos casos sintéticos ao invés de replicar casos existentes, mas não enfatiza casos raros. A combinação desses algoritmos, chamada de Clusterbased Smote, apresentou resultados melhores do que a aplicação deles em separado em oito das nove bases de dados utilizadas proposta nesta pesquisa. A outra abordagem proposta nesta pesquisa visa a diminuir a sobreposição de classes possivelmente provocada pela aplicação do método SMOTE. Intuitivamente, esta abordagem consiste em guiar a aplicação do SMOTE com a aprendizagem não supervisionada proporcionada pela clusterização. O método implementado sob esta abordagem, denominado de C-clear, resultou em melhora significativa em relação ao SMOTE em três das nove bases testadas e empatou nas demais. Foi também proposta uma nova abordagem para limpeza de dados baseada na aprendizagem não supervisionada, a qual foi incorporada ao C-clear. Esta limpeza somente surtiu melhora em uma base de dados, sendo este baixo desempenho oriundo possivelmente da escolha não adequada de seus parâmetros de limpeza. A aprendizagem destes parâmetros a partir dos dados ficou como trabalho futuro. ___________________________________________________________________________________________ ABSTRACT / It is intended in this work to research methods that improve the accuracy of classifiers applied to data set with class imbalance (high skew in class distribution causing rare classes) and within-class imbalance (high skew in data within-class distribution causing care cases). Standard classifier algorithms are strongly affected by these characteristics and their generated model are biased to the majority classes (or cases), in detriment of classes (or cases) underrepresented. Generally, models generated with imbalanced data set suffer from low accuracy for the minority classes, which is a problem when the target class is one of them. Eventually, rare cases are likely of being ignored by inductors, which is a problem when they belong to the interesting class (or classes). A new method is proposed in this work, Cluster-based Smote, which combines the methods Cluster-based Oversampling (oversampling by replication of positive cases guided by clusters) and SMOTE (Synthetic Minority Oversampling Technique). Cluster-based Oversampling addresses small disjuncts, but overfits the model to the training set. The method SMOTE addresses the overfit problem of random oversampling, but does not treat rare cases. The combination of them proposed in this research, named Cluster-based Smote, presented better results in eight out of nine datasets, compared to the applying of them all alone. Another approach proposed in this research aims at reducing the class overlap problem possibly caused by applying SMOTE. The main idea is to guide the SMOTE process by non-supervised learning (with clustering techniques). The method implemented under this approach, named Cclear, resulted in significant improvement over SMOTE in three out of nine datasets. A cleaning method based in the non-supervised learning was also proposed and has been incorporated in the C-clear method. The cleaning method improved the results in only one dataset, probably because of the not so well values chosen as cleaning parameters. The learning of these parameters from the data is left as a future work.
80

Vývoj, souvislosti a perspektivy pěstování geneticky upravených a "clear field" plodin v kontextu světového zemědělství. / Development, causalities and perspectives of cultivation of genetically modified and "clear field" crops in the context of world agriculture.

Němečková, Lucie January 2016 (has links)
The introduction of genetically modified crops raised controversial reactions that divide not only the professional community into two camps. Considering that rapeseed, soya beans and corn belong to the most important crops of the world, significant attention is given to the development of their GM varieties. Based on available information, a comparative study was compiled involving the effects of genetically modified varieties of these crops on the environment, human and animal health and socio-economic area. The cultivation of genetically modified crops is profitable especially for companies developing these varieties and for the growers. However it was found that the reduction of the amount of applied herbicides was not achieved as expected. Additionally a negative affect of the active herbicide substances on the environment and human and animal health has been shown. There is a positive impact of the reduction in carbon dioxide emissions due to less frequent entries into the stands. Feeding with GM products also manifested in negative way. There is a very risky possibility of crossing and emergence of resistant weeds, in particular rape and related species as well. The reduction of biodiversity, which is often discussed, was not confirmed in all cases. The changes in the microbial community in the soil have been demonstrated. The coexistence of GM crops with conventional agriculture, and even more ecological agriculture has been shown as problematic. In accordance with the findings, it is recommended to follow the precautionary principles, to follow the varied crop rotation and to target the production to sustainable agriculture, verified by time and experience.

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