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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.
41

The effects of part–of–speech tagging on text–to–speech synthesis for resource–scarce languages / G.I. Schlünz

Schlünz, Georg Isaac January 2010 (has links)
In the world of human language technology, resource–scarce languages (RSLs) suffer from the problem of little available electronic data and linguistic expertise. The Lwazi project in South Africa is a large–scale endeavour to collect and apply such resources for all eleven of the official South African languages. One of the deliverables of the project is more natural text–to–speech (TTS) voices. Naturalness is primarily determined by prosody and it is shown that many aspects of prosodic modelling is, in turn, dependent on part–of–speech (POS) information. Solving the POS problem is, therefore, a prudent first step towards meeting the goal of natural TTS voices. In a resource–scarce environment, obtaining and applying the POS information are not trivial. Firstly, an automatic tagger is required to tag the text to be synthesised with POS categories, but state–of–the–art POS taggers are data–driven and thus require large amounts of labelled training data. Secondly, the subsequent processes in TTS that are used to apply the POS information towards prosodic modelling are resource–intensive themselves: some require non–trivial linguistic knowledge; others require labelled data as well. The first problem asks the question of which available POS tagging algorithm will be the most accurate on little training data. This research sets out to answer the question by reviewing the most popular supervised data–driven algorithms. Since literature to date consists mostly of isolated papers discussing one algorithm, the aim of the review is to consolidate the research into a single point of reference. A subsequent experimental investigation compares the tagging algorithms on small training data sets of English and Afrikaans, and it is shown that the hidden Markov model (HMM) tagger outperforms the rest when using both a comprehensive and a reduced POS tagset. Regarding the second problem, the question arises whether it is perhaps possible to circumvent the traditional approaches to prosodic modelling by learning the latter directly from the speech data using POS information. In other words, does the addition of POS features to the HTS context labels improve the naturalness of a TTS voice? Towards answering this question, HTS voices are trained from English and Afrikaans prosodically rich speech. The voices are compared with and without POS features incorporated into the HTS context labels, analytically and perceptually. For the analytical experiments, measures of prosody to quantify the comparisons are explored. It is then also noted whether the results of the perceptual experiments correlate with their analytical counterparts. It is found that, when a minimal feature set is used for the HTS context labels, the addition of POS tags does improve the naturalness of the voice. However, the same effect can be accomplished by including segmental counting and positional information instead of the POS tags. / Thesis (M.Sc. Engineering Sciences (Electrical and Electronic Engineering))--North-West University, Potchefstroom Campus, 2011.
42

The effects of part–of–speech tagging on text–to–speech synthesis for resource–scarce languages / G.I. Schlünz

Schlünz, Georg Isaac January 2010 (has links)
In the world of human language technology, resource–scarce languages (RSLs) suffer from the problem of little available electronic data and linguistic expertise. The Lwazi project in South Africa is a large–scale endeavour to collect and apply such resources for all eleven of the official South African languages. One of the deliverables of the project is more natural text–to–speech (TTS) voices. Naturalness is primarily determined by prosody and it is shown that many aspects of prosodic modelling is, in turn, dependent on part–of–speech (POS) information. Solving the POS problem is, therefore, a prudent first step towards meeting the goal of natural TTS voices. In a resource–scarce environment, obtaining and applying the POS information are not trivial. Firstly, an automatic tagger is required to tag the text to be synthesised with POS categories, but state–of–the–art POS taggers are data–driven and thus require large amounts of labelled training data. Secondly, the subsequent processes in TTS that are used to apply the POS information towards prosodic modelling are resource–intensive themselves: some require non–trivial linguistic knowledge; others require labelled data as well. The first problem asks the question of which available POS tagging algorithm will be the most accurate on little training data. This research sets out to answer the question by reviewing the most popular supervised data–driven algorithms. Since literature to date consists mostly of isolated papers discussing one algorithm, the aim of the review is to consolidate the research into a single point of reference. A subsequent experimental investigation compares the tagging algorithms on small training data sets of English and Afrikaans, and it is shown that the hidden Markov model (HMM) tagger outperforms the rest when using both a comprehensive and a reduced POS tagset. Regarding the second problem, the question arises whether it is perhaps possible to circumvent the traditional approaches to prosodic modelling by learning the latter directly from the speech data using POS information. In other words, does the addition of POS features to the HTS context labels improve the naturalness of a TTS voice? Towards answering this question, HTS voices are trained from English and Afrikaans prosodically rich speech. The voices are compared with and without POS features incorporated into the HTS context labels, analytically and perceptually. For the analytical experiments, measures of prosody to quantify the comparisons are explored. It is then also noted whether the results of the perceptual experiments correlate with their analytical counterparts. It is found that, when a minimal feature set is used for the HTS context labels, the addition of POS tags does improve the naturalness of the voice. However, the same effect can be accomplished by including segmental counting and positional information instead of the POS tags. / Thesis (M.Sc. Engineering Sciences (Electrical and Electronic Engineering))--North-West University, Potchefstroom Campus, 2011.
43

Will the conflict concerning the Human Terrain System continue?

Lilliestråle, Märtha January 2011 (has links)
Human Terrain System has been describes as: “Not since World War II has a military consulting been endorsed so publicly; not since Vietnam had it been condemned so fiercely.” The purpose of this essay is to describe what the controversy and the critique presented against HTS consists off and to see if there is a beginning to a solution in some way. HTS is embedding socials scientists within military deployed units and it is argued to violate the ethic codes of research. Pauline Kusiak has presented a solution to the conflict. By analysing the arguments in the public debate between the anthropologists against and HTS’s advocates the purpose is to answer if the U.S. Military recognise the tensions between anthropology methods and their embedding in HTS? To measure ‘recognition’ the model of ‘The Feedback Stair’ is used. The answer is that the tension is not recognised and it supports the hypothesis that the U.S. Military are not at the first step one the solution presented by Kusiak to diminish ‘the civilian-military gap.
44

Výtěžnost oleje vybraných odrůd slunečnice roční [Helianthus annuus L.] pěstované v rozdílných systémech pěstování

Bartoš, Radek January 2016 (has links)
The main objective of presented thesis was comparing cultivation of sunflower (Helianthus annuus L.) in convetional way of farming and organic farming. Experient was founded in Lanžhot (Břeclav district) in 2015. We evaluated the phenological phases BBCH and weather. These parameters were determined in harvested achenes: yield, HTS, moisture, oiliness, oil yield. Further, we calculated the direct costs, cost efficiency and return of sales. Results showed differences between conventional farming and organic farming. It could be explained by atypical course of weather in 2015
45

Antenas de microfita com patch supercondutor a 212 K

Maia, Hugo Michel C?mara de Azevedo 09 July 2010 (has links)
Made available in DSpace on 2014-12-17T14:55:45Z (GMT). No. of bitstreams: 1 HugoMCAM_DISSERT_partes autorizadas.pdf: 586809 bytes, checksum: e96d1467d4ab6c5fa6da39927cde0bca (MD5) Previous issue date: 2010-07-09 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This work has as main objective to study the application of microstrip antennas with patch and use of superconducting arrays of planar and linear phase. Was presented a study of the main theories that explain clearly the superconductivity. The BCS theory, Equations of London and the Two Fluid Model are theories that supported the implementation of the superconducting microstrip antennas. Arrangements phase was analyzed in linear and planar configuration of its antennas are reported factors such arrays to settings and criteria of phase and the spacing between the elements that make the arrayst was reviewed in order to minimize losses due to secondary lobes. The antenna used has a rectangular patch Sn5InCa2Ba4Cu10Oy the superconducting material was analyzed by the method of Transverse Transmission Line (TTL) applied in the field of Fourier transform (FTD). The TTL is a full-wave method, which has committed to obtaining the electromagnetic fields in terms of cross-cutting components of the structure. The inclusion of superconducting patch is made using the boundary condition, complex resistive. Are obtained when the resonant frequency depending on the parameters of the antenna, radiation pattern of E-Plan and H-Plan for the M-phase arrangements of antennas in the linear and planar configurations for different values of phase and spacing between the elements. / Este trabalho tem como objetivo principal o estudo da aplica??o de antenas de microfita com patch supercondutor e uso dos arranjos de fase linear e planar. Foi apresentado um estudo das principais teorias que explicam com clareza a supercondutividade. As teorias BCS, Equa??es de London e modelo dos Dois Fluidos s?o as teorias que d?o suporte a aplica??o dos supercondutores nas antenas de microfita. Os arranjos de fase foram analisados em configura??es lineares e planares de suas antenas. Foram obtidos os fatores de arranjos para tais configura??es e os crit?rios da fase e do espa?amento entre os elementos que comp?e o arranjo, ao qual foram examinados com o objetivo de obter um l?bulo principal com alta diretividade e alto ganho. A antena utilizada tem como patch retangular o material supercondutor Sn5InCa2Ba4Cu10Oy foi analisada atrav?s do m?todo da Linha de Transmiss?o Transversa (LTT), aplicado no dom?nio da transformada de Fourier (FTD). O LTT ? um m?todo de onda completa, que tem como regra a obten??o dos campos eletromagn?ticos em termos das componentes transversais ? estrutura. A inclus?o do patch supercondutor ? feita utilizando-se a condi??o de contorno complexa resistiva. S?o obtidos resultados da freq??ncia de resson?ncia em fun??o dos par?metros da antena; diagramas de radia??o do Plano-E e Plano-H para os arranjos de fase de antenas nas configura??es lineares e planares para diferentes valores da fase e espa?amento entre os elementos.
46

Targeting Autopalmitoylation to Modulate Protein S-Palmitoylation

Hamel, Laura Dawn 18 November 2015 (has links)
Palmitoylation refers to the covalent attachment of fatty acids, such as palmitate, onto the cysteine residues of proteins. This process may subsequently alter their localization and function. Nearly all of the enzymes that catalyze palmitoylation, zDHHC protein acyl transferases (PATs), are implicated in neurological disorders, infectious diseases, and cancer in humans. Of particular interest to those who study palmitoylation are Ras family GTPas and zDHHC9-GCP16, the zDHHC PAT that palmitoylates Ras proteins. Erf2-Erf4 is the zDHHC PAT that palmitoylates Ras proteins in Saccharomyces cerevisiae. Currently, there are no methods to therapeutically target palmitoylation for the treatment of disease. One of the barriers to identifying a modulator of palmitoylation is the lack of a reliable high-throughput screening system. To date, few assay systems have been developed to examine the kinetics and mechanism of that palmitoylation reaction. This lab has developed a fluorescence-based coupled assay to gain insight into the enzymology, biochemical mechanism, and kinetics of the palmitoylation reaction. This assay may be used to identify specific inhibitors of autopalmitoylation. In the first step of this reaction, the palmitoyl-moiety from palmitoyl-CoA is transferred to the zDHHC9 PAT cysteine side chain to form a palmitoyl:enzyme intermediate. The second step of palmitoylation is the subsequent transfer of the palmitoyl-moiety from the palmitoyl:enzyme intermediate to the cysteine residue of the substrate protein. This fluorescence-based coupled assay was utilized to screen a natural products library and a unique synthetic compound library for inhibitors of Erf2 autopalmitoylation. These screens led to the identification of fungal metabolite extracts and ten bis-cyclic piperazine compounds that inhibit Erf2 autopalmitoylation in the low micromolar range. This effect is similar to known inhibitors of palmitoylation that lack specificity for the palmitoylation reaction itself.
47

AC losses in superconductors : a multi-scale approach for the design of high current cables / Pertes AC dans les supraconducteurs : une approche multi-échelle pour le dimensionnement de câbles fort courant

Escamez, Guillaume 21 October 2016 (has links)
Le travail de cette thèse porte sur l'étude des pertes AC dans les supraconducteurs pour des applications tels que les câbles ou les aimants. Les modélisations numériques rapportées sont de type éléments-finis et méthode intégrale. Toutes ces méthodes visent à résoudre à calculer les distributions de densité de courant et de champ magnétique en prenant en compte différents loi de comportement pour le supraconducteur. Deux conducteurs sont introduits dans ce mémoire. Tout d'abord, les supraconducteurs à haute température critiques sont étudiées avec l'introduction d'une nouvelle forme de conducteur (fils cylindriques) et sont envisagés pour des câbles fort courant de 3~kA. Dans un second temps, des simulations numériques 3-D sont réalisés sur un conducteur MgB2. Le chapitre suivant traite des contraintes de calculs des pertes dans le but de dimensionner l'ensemble des pertes d'un câble complet. Enfin, les modèles numériques développés précédemment sont utilisé sur un exemple concret : le démonstrateur 10~kA fait à l'aide du conducteur MgB2 dans le projet BEST-PATHS / The work reported in this PhD deals with AC losses in superconducting material for large scale applications such as cables or magnets. Numerical models involving FEM and integral methods have been developed to solve the time transient electromagnetic distributions of field and current density with the peculiarity of the superconducting constitutive E-J equation. Two main conductors have been investigated for two ranges of superconducting cables. First, REBCO superconductors working at 77 K are studied and a new architecture of conductor (round wires) for 3~kA cables. Secondly, for very high current cables, 3-D simulations on MgB2 wires are approach and solved using FEM modeling. The following chapter introduced new development used for the calculation of AC losses in DC cables. The thesis ends with the use of the developed numerical model on a practical example in the BEST-PATHS project: a 10 kA MgB2 demonstrator.
48

Vliv lanthanoidů na fázové transformace vysokoteplotní supravodivé keramiky řady Bi / Influence of noble earth's elements on Bi based high temperature superconductors phase transition

Snopek, Jan January 2009 (has links)
The Bi2Sr2CaCu2O7+d, i.e. Bi2212 phase of bismuth derived high temperature superconductors (HTS), powder precursor were synthesized via sol – gel technique using ethylendiamintetraacetic acid (Chelaton II) as a chelating agent. Metal nitrate’s solutions were mixed with EDTA suspension. The pH value was adjusted to 9 by NH4OH by reason forming of stable metal’s complexes. The mixture was heated to 80 °C for gelation. Solution taken before solid gel was form is used for preparation of Bi2212 layer on to a-Al2O3 surface via spin coating deposition’s technique. Reactive powder used for bulk sample preparation was made by calcination (800 °C) of pyrolyzed xerogel (500 °C). Sintering in oxygen atmosphere was proceeding at temperature from 850 to 880 °C. Bulk sample properties were compared with sample prepared by common ceramic method. Simultaneous TG-DTA, IR spectroscopy and heating microscopy were used for sample characterization. Furthermore, construction of furnace for sintering in O2 atmosphere was described.
49

Uplatnění vybraných forem zinku při mimokořenové výživě kukuřice

Pajl, Jaroslav January 2019 (has links)
This thesis deals with the influence of foliar application of selected forms of zinc on the yield and quality of corn grain (Zea mays L.). The issue was dealt with in the form of a small-plot vegetation experiment on the landfill site in Žabčice. Zinc was applied in the 6-8 leaf phase in three forms of ZnO, ZnSO4 and Zn-EDTA at doses of 100, 250 and 500 g.ha-1 in each of them. A zinc-free variant was used as a control. In the course of vegetation (14 days after fertilizer application (20 June 2018)) and after harvesting, an inorganic analysis of the plants (Zn content) was carried out, NDVI and NDRE index were determined during vegetation. After harvest, the yield, starch content and weight of a thousand seeds were determined. Zinc fertilization proved to be (p≤0.05) affected by the zinc content during vegetation, but had no effect on NDVI and NDRE index. Grain yield was positively influenced, although no proven zinc effect was demonstrated. WTS and starch content in the grain were neither demonstrably affected nor significantly different from control. Zinc content in the grain was not significantly affected, but zinc fertilization was positive.
50

The Relationship Between Inhibition, Conformation, and Catalysis of the Aminopeptidase ERAP1

Maben, Zachary 15 November 2018 (has links)
ERAP1 is an aminopeptidase that is a component of antigen processing. To distinguish the role of ERAP1 from homologs ERAP2 and IRAP, I identified three specific ERAP1 inhibitors via a high-throughput screen. These compounds inhibit hydrolysis of a decamer peptide, and some inhibit ERAP1 in a cellular assay. These inhibitors enable dissection of ERAP1 mechanism. ERAP1 has been crystallized in two conformations: open and closed. I collected SAXS data on ERAP1 in the presence of various inhibitors. ERAP1 adopts an open conformation in solution, but some inhibitors stabilize the closed form. Compound 3 docks to a distal pocket 28Å from the active site zinc, while DG013 and DG014 bind to the active site. This distal pocket is an allosteric activation site, and allostery is mediated by stabilizing the closed state. I also identified an intermediate step in substrate binding where helix 4a becomes ordered while ERAP1 maintains an open conformation. Helix 4a then rotates and engages substrate when ERAP1 closes. The nonsynonymous SNP rs30187 at position 528 (Lys/Arg) subtly alters ERAP1 activity in vitro and correlates with disease incidence. Position 528 forms a conformation-dependent electrostatic interaction with Glu913 in the closed structure. The energetic contribution of this interaction is stronger for Lys528 than Arg528. Inhibitors that induce closing are more potent for Lys528 than Arg528. I propose a model where either helix 4a stabilization or allosteric site occupancy shift the conformational equilibrium towards a closed state, while substitution at position 528 alters the opening rate.

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