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Dissertations / Theses on the topic 'DCCD'

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Published: 4 June 2021
Last updated: 17 February 2022

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1

AlShammeri, Mohammed. "Dynamic Committees for Handling Concept Drift in Databases (DCCD)." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/23498.

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Concept drift refers to a problem that is caused by a change in the data distribution in data mining. This leads to reduction in the accuracy of the current model that is used to examine the underlying data distribution of the concept to be discovered. A number of techniques have been introduced to address this issue, in a supervised learning (or classification) setting. In a classification setting, the target concept (or class) to be learned is known. One of these techniques is called “Ensemble learning”, which refers to using multiple trained classifiers in order to get better predictions by using some voting scheme. In a traditional ensemble, the underlying base classifiers are all of the same type. Recent research extends the idea of ensemble learning to the idea of using committees, where a committee consists of diverse classifiers. This is the main difference between the regular ensemble classifiers and the committee learning algorithms. Committees are able to use diverse learning methods simultaneously and dynamically take advantage of the most accurate classifiers as the data change. In addition, some committees are able to replace their members when they perform poorly. This thesis presents two new algorithms that address concept drifts. The first algorithm has been designed to systematically introduce gradual and sudden concept drift scenarios into datasets. In order to save time and avoid memory consumption, the Concept Drift Introducer (CDI) algorithm divides the number of drift scenarios into phases. The main advantage of using phases is that it allows us to produce a highly scalable concept drift detector that evaluates each phase, instead of evaluating each individual drift scenario. We further designed a novel algorithm to handle concept drift. Our Dynamic Committee for Concept Drift (DCCD) algorithm uses a voted committee of hypotheses that vote on the best base classifier, based on its predictive accuracy. The novelty of DCCD lies in the fact that we employ diverse heterogeneous classifiers in one committee in an attempt to maximize diversity. DCCD detects concept drifts by using the accuracy and by weighing the committee members by adding one point to the most accurate member. The total loss in accuracy for each member is calculated at the end of each point of measurement, or phase. The performance of the committee members are evaluated to decide whether a member needs to be replaced or not. Moreover, DCCD detects the worst member in the committee and then eliminates this member by using a weighting mechanism. Our experimental evaluation centers on evaluating the performance of DCCD on various datasets of different sizes, with different levels of gradual and sudden concept drift. We further compare our algorithm to another state-of-the-art algorithm, namely the MultiScheme approach. The experiments indicate the effectiveness of our DCCD method under a number of diverse circumstances. The DCCD algorithm generally generates high performance results, especially when the number of concept drifts is large in a dataset. For the size of the datasets used, our results showed that DCCD produced a steady improvement in performance when applied to small datasets. Further, in large and medium datasets, our DCCD method has a comparable, and often slightly higher, performance than the MultiScheme technique. The experimental results also show that the DCCD algorithm limits the loss in accuracy over time, regardless of the size of the dataset.
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2

Omolewu, Rachel. "Characterization of Three Mutations in Conserved Domain of Subunit III of Cytochrome c Oxidase from Rhodobacter sphaeroides." Wright State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=wright1292612174.

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3

Moffat, Jeffrey C. "Properties of Conductance and Inhibition of Proton Channels: M2 from Influenza A Virus and Fo from Escherichia coli ATP Synthase." BYU ScholarsArchive, 2006. https://scholarsarchive.byu.edu/etd/479.

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Proton channels are essential for many of the processes of life. The influenza A viral protein M2 is responsible for sensing the conditions necessary for viral RNA release. The proton-translocating FoF1 ATPase (ATP synthase) uses a proton gradient to drive adenosine triphosphate (ATP) synthesis. We have directly measured proton uptake in vesicles containing reconstituted M2 or FO by monitoring external pH after addition of valinomycin to vesicles with 100-fold diluted external [K+]. This proton flux assay was utilized to quantify proton flux through single M2 and Fo channels. Contrary to previous reports, proton uptake by M2 was not significantly altered by acidification of the extravesicular pH. We conclude that pH only weakly affects proton flux through M2 in the pH range of 5.4 - 7.0. Theoretical analysis utilized for such vesicle uptake assays illuminates the appropriate time scale of the initial slope and an important limitation that must be placed on inferences about channel ion selectivity. The rise in pH over 10 seconds after ionophore addition yielded time-averaged single channel conductances of 0.35±0.2 aS and 0.72±0.4 aS at pH 5.4 and 7.0 respectively. Such a low time-average conductance implies that M2 is only conductive 10^-6 to 10^-4 of the time. M2 selectivity for hydrogen over potassium is ~10^7. Fo translocates protons across membranes, converting electrochemical energy to rotational inertia. Previous experiments have been partially confounded by a contaminating channel, CL, which co-purifies with Fo and leaks cations. CL activity is shown to not decrease following deletion of the previously uncharacterized yraM open reading frame of E. coli. Fo purified from a deletion strain lacking yraM is just as active as Fo purified from the wild-type strain. Using Fo from the deletion strain, the single-hit hypothesis of DCCD inhibition of passive proton flux through Fo was examined. A DCCD-induced reduction in ATP synthase activity correlates with a reduction in the total initial slope, the number of functional Fo per µg protein, and the single channel proton flux. At least 2 DCCD per Fo are required to totally inactivate passive proton flux. M2 and Fo have similar single channel conductances but different open probabilities.
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4

Jonnalagadda, Sneha R. "Molecular Modulation of a-Subunit VISIT-DG Sequence Residue Asp-350 in the Catalytic sites of Escherichia coli ATP Synthase." Digital Commons @ East Tennessee State University, 2011. https://dc.etsu.edu/etd/1296.

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ATP Synthase is the fundamental means of cellular energy production in animals, plants, and almost all microorganisms. In order to understand the mechanism of ATP catalysis, critical amino acid residues involved in Pi binding have to be identified. The αVISIT-DG sequence at the interface of α/β subunits that contains residues from 345-351 is highly conserved and αAsp-350 has been chosen because of its negative charge side chain and its close proximity (~2.8 Å) to the known phosphate binding residue αArg-376. The mutant's αD350R, αD350Q, αD350A, αR376A/D, and αG351R/A/D were generated by site directed mutagenesis and several biochemical assays were performed on them to understand the role played by the amino acid residues in Pi binding. Biochemical results suggest that αD350 may be involved in catalysis of ATP synthase and play an important role in Pi binding, whereas αG351 may be involved only in the structural integrity.
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5

Barbagallo, Mariano. "HV Interleaved Multiphase DcDc Buck-Boost Converter." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017.

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in electric vehicle (ev) systems, bi-directional dc-dc converters are used to interface the rechargeable energy storage system (ress) such as the battery bank with the high voltage dc-link of the inverter. currently multi-cell batteries used in automotive systems, such as ev or hev, are subject to a higher failure rate than single cell batteries. the more cells are used in series, the greater the opportunities to fail and the worse the reliability. when a cell has failed the entire string or even worse the battery must be replaced, which is extremely costly [1]. so, to have less cells in series increases the reliability of the system, which also leads to a lower voltage of the dc link. for this reason and many others, in a hybrid or electric vehicle powertrain, a boost dc-dc converter enables optimization of the battery system. this work aims to investigate all the benefits that come with interleaving technique in dc-dc converters for automotive systems. indeed, these kind of converters for use in high-performance and high-power applications have received increasing interest in recent years. in particular this research work, done with sevcon ltd focuses on the theory behind bi-directional multiphase interleaved (imc) converter and how it could be used to interface a rechargeable energy storage system (ress) to the powertrain of a hybrid or electric vehicle. more specifically, it was investigated if it is possible to use (after appropriate hardware and software amendments) a standard three phase ac motor inverter as a multiphase interleaved converter. for this purpose two motor controller, produced by sevcon have been analysed. both the gen4 size 10 and the hvlp inverters were considered for use as a dc-dc converter. the voltage can step up or down based on the power flow direction. each phase is indeed a bi-directional buck or boost converter, which is composed of a bridge of power switches and inductor.
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6

Poliszuk, Shirley. "Kinetics of DCOD consumption by bacterial suspensions." ScholarWorks@UNO, 2004. http://louisdl.louislibraries.org/u?/NOD,169.

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Thesis (M.S.)--University of New Orleans, 2004.
Title from electronic submission form. "A thesis ... in partial fulfillment of the requirements for the degree of Master of Science in Environmental Engineering."--Thesis t.p. Vita. Includes bibliographical references.
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7

Rodríguez, González Hortencia Naizzara. "Apuestas literarias en el Caribe colombiano: Luis Carlos López, Oscar Delgado y Jorge Artel. Poesía y periodismo en contrapunteo con el provincianismo nacional (1990-1948)." Thesis, Universidad de las Américas Puebla, 2012. http://catarina.udlap.mx/u_dl_a/tales/documentos/dctd/rodriguez_g_hn/.

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8

Kurjenoja, Lounassaari Anne Kristiina. "Arquitectura con visión femenina: el cuerpo como nueva centralidad sensible." Thesis, Universidad de las Américas Puebla, 2010. http://catarina.udlap.mx/u_dl_a/tales/documentos/dctd/kurjenoja_l_ak/.

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9

Childs, Edward William. "The roles of the locust DCMD in collision detection." Thesis, University of Newcastle Upon Tyne, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.300191.

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10

Pereira, Villarroel Sergio Alejandro. "Portal de Proyectos Externos del DCC." Tesis, Universidad de Chile, 2010. http://www.repositorio.uchile.cl/handle/2250/103723.

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El objetivo general del presente trabajo de título es desarrollar un portal de Proyectos Externos que permita al Departamento de Ciencias de la Computación (DCC) mejorar: (1) el vínculo con las Empresas y (2) la gestión interna del área. Se espera que éste pueda dar a conocer a la industria los proyectos realizados dentro del Departamento, promover la realización de nuevos proyectos, y, también, permitir una mejor toma de decisiones en futuras gestiones dentro del área. El DCC realiza constantemente diversos proyectos de extensión relacionados con Empresas externas. En la actualidad, no existe ningún lugar donde quede registro de éstos proyectos, sino que simplemente son los profesores encargados quienes mantienen esta información. Frente a lo cual, se torna complejo el proceso de obtención de aquella información. Es por esta razón, que se propone el “Portal de Proyectos Externos del DCC”. Es decir, una aplicación web que permita el manejo de la información en un lugar centralizado, lo cual facilitará el acceso para quienes busquen conocer los proyectos que el Departamento realiza. En este portal, se da solución a los problemas planteados mediante una aplicación a la que se accede vía web, en la cual Alumnos, Empresas y Profesores son partícipes en el debido proceso de publicaciones y postulaciones a proyectos. Más aún, se dispone de información suficiente como para poder tener conocimiento de lo que el Departamento está realizando. De la misma forma, la aplicación se integra a módulos estadísticos que permiten obtener reportes inmediatos para un Administrador, a quién se le facilita la gestión y toma de decisiones para futuros proyectos. El resultado final ha sido satisfactorio e interesante al mismo tiempo, puesto que han surgido mayores interesados que los que se esperaban, permitiendo dar aún mayores soluciones que las propuestas y generando expectativas para posibles trabajos futuros a realizar, tomando como base lo hecho hasta ahora. Asimismo, los usuarios de este portal se hacen partícipes de éste, logrando en una primera instancia acercamientos que previo a la realización de este trabajo no se tenían. Se concluye que el portal permitirá un mayor acercamiento con la industria, comportándose como una vitrina frente al mundo exterior. Por otro lado, se podrá llevar a cabo una mayor gestión interna dentro del DCC, obteniéndose estadísticas de cantidad y desempeño de proyectos a lo largo del tiempo.
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11

Borghi, Alexandre Augusto. "Degradação de cloridrato de doxiciclina pelo processo Fenton." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/9/9135/tde-17042014-102740/.

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O aumento no consumo de antibióticos por seres humanos e animais tem elevado a sua concentração na sua forma inalterada ou de seus metabólitos, que chegam às estações de tratamento de efluentes, onde os tratamentos convencionais são incapazes de degradar estas moléculas, sendo liberadas diretamente nos corpos d\'água receptores. A liberação destas moléculas no meio ambiente tem proporcionado a seleção de organismos patogênicos resistentes, capazes de transmitir geneticamente esta característica a seus descendentes. Este trabalho tem como objetivo o estudo da degradação da molécula de cloridrato de doxiciclina, por ser um antibiótico de largo espectro da família das tetraciclinas, através do processo Fenton. Foram determinados neste trabalho as influências da temperatura, concentração inicial de peróxido de hidrogênio, concentração inicial de íon ferroso e do pH sobre a concentração residual de cloridrato de doxiciclina, concentração residual de peróxido de hidrogênio, concentração de íon ferroso e de carbono orgânico total (COT) em função do tempo de reação. Os métodos analíticos empregados foram baseados em espectrofotometria, análise instrumental para a determinação do carbono orgânico total (COT), titulometria e cromatografia líquida (CLAE) com detectores de UV e de massa. Testes preliminares mostraram que as melhores condições operacionais de temperatura, concentrações de íon ferroso e de peróxido de hidrogênio estariam ao redor de CFe2+ = 62,5 mg/L, CH2O2 = 500 mg/L e T = 20ºC. Estas condições foram utilizadas como ponto central do planejamento fatorial do tipo Delineamento Composto Central Rotacional (DCCR). Os resultados do planejamento tratados com o software Statistica® mostraram que as condições operacionais para a menor concentração residual de fármaco (0 mg/L) e redução de 40,9% da carga orgânica em solução deveriam estar ao redor de concentração de íon ferroso, CFe2+ = 25 mg/L, concentração de peróxido de hidrogênio, CH2O2 = 611 mg/L e temperatura = 35ºC, das quais a variável CH2O2 apresentou a maior importância estatística. Ao redor destas condições foi feita uma análise paramétrica para se verificar as influências individuais da temperatura, CFe2+, CH2O2 e da relação CFe2+/ CH2O2. Também foi testada a citotoxicidade dos resíduos gerados. Este estudo mostrou que a variável de maior importância sobre o processo foi a concentração de peróxido de hidrogênio, que tem relação direta com a razão CFe2+/ CH2O2 apresentado melhores resultados quando esta é mantida igual a 0,16. Houve melhora acentuada na mineralização da matéria orgânica com a inserção de microbolhas de ar, obtendo assim redução de até 44% da matéria orgânica em relação à concentração inicial de carbono orgânico de 55 mg/L. Apesar da baixa mineralização obtida pelo estudo, o processo Fenton se mostrou promissor na degradação do cloridrato de doxiciclina, devido principalmente ao fato de os resíduos de degradação não possuírem ação inibitória sobre o organismo teste Escherichia coli e nem citotoxicidade sobre as células L-929, evidenciando que as propriedades antibióticas da molécula foram inativadas, inibindo a capacidade de promover a resistência bacteriana a este antibiótico.
The increasing consumption of antibiotics by humans and animals have increased their concentrations in the environment in their unchanged form or of their metabolites, that reach public wastewater treatment plants, which are unable to degrade these molecules, and are released into surface waters. The release of these molecules in the environment has caused the selection of resistant pathogenic organisms, genetically capable of transmitting this feature to their descendants. This work has as objective the study of the degradation of doxycycline hydrochloride, which is a common broad-spectrum antibiotic of the tetracycline family, by the Fenton process. In this work were determined the influences of temperature, initial hydrogen peroxide concentration, initial ferrous ion concentration and of pH on the final residual concentration of doxycycline, residual concentration of hydrogen peroxide, residual concentration of ferrous ion and total organic carbon (TOC) along the reaction time, using titrations and instrumental analytical techniques as spectrophotometry, TOC analyzer and high performance liquid chromatography (HPLC) with UV and mass detectors. Preliminary tests showed that the best operating conditions of temperature, concentrations of ferrous ion and hydrogen peroxide would be around CFe2+ = 62.5 mg/L, CH2O2 = 500 mg/L and T = 20°C. These conditions were use d as the central point of the Central Composite Rotational Design (DCCR). The results of the experimental planning were treated with the Statistica® software and it was showed that the operational conditions for the smallest residual drug concentration (0 mg/L) and 40.9% TOC reduction should be around ferrous ion concentration, CFe2+ = 25 mg/L, concentration of hydrogen peroxide, CH2O2 = 611 mg/L and temperature = 35°C. The hydrogen peroxide exhibited the highest statistical importance of the studied variables. It was accomplished a parametric study around the best operational conditions inferred from the statistical analysis to check the individual influences of temperature, CFe2+, CH2O2 and the ratio CFe2+/ CH2O2. It was also verified the cytotoxicity of the reaction mediums after the end of the experiments. This study showed that the process is highly dependent of the hydrogen peroxide concentration, directly related to the ratio CFe2+/ CH2O2 and presented the best results when this ratio was kept equal to 0.16. It was observed a marked improvement in the mineralization of the organic matter, up to 44% reduction of the initial TOC value of 55 mg/L, when air was pumped to the reaction medium. Despite the low mineralization obtained in this study, the Fenton process proved to be promising in the degradation of doxycycline hydrochloride, due mainly to the low cytotoxicity of the residues. It was observed neither inhibitory action on the test organism Escherichia coli nor cytotoxicity on L-929 cells, indicating that the antibiotic properties of the molecule had been inactivated and also its ability to stimulate bacterial resistance to this antibiotic.
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12

Froldi, Carlos Augusto 1979. "Uma variação do protocolo DCCP para redes de alta velocidade." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/275723.

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Orientador: Nelson Luis Saldanha da Fonseca
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação
Made available in DSpace on 2018-08-19T17:25:04Z (GMT). No. of bitstreams: 1 Froldi_CarlosAugusto_M.pdf: 543951 bytes, checksum: e4f64a2921c88fd1461445bd39a04278 (MD5) Previous issue date: 2011
Resumo: Os protocolos da camada de transporte na Internet, TCP e UDP, não oferecem serviços para transmissão eficiente de fluxos multimídia, porém, este último é adotado com maior freqüência por essas aplicações. Uma proposta de um novo protocolo da camada de transporte, chamado DCCP, foi elaborada para atender a demanda das aplicações multimídia e substituir o protocolo UDP. A presente dissertação propõe uma variante deste protocolo, chamada Fast DCCP, para operar de maneira eficiente em redes de alta velocidade. A nova variante foi avaliada através de experimentos de simulação, utilizando o NS-2 e experimentos de medição, utilizando o sistema operacional Linux
Abstract: The Internet transport layer protocols, TCP and UDP, do not provide efficient transport service for multimedia streams. UDP is usually used for these applications, due to its low overhead. A new transport layer protocol, called DCCP, was proposed to meet the demand of multimedia applications, aiming at replacing the UDP protocol. This dissertation will propose a variant for this protocol, called Fast DCCP, for operating efficiently on high-speed networks. It was evaluated by simulation using the NS-2 network simulator and measurements of the FAST DCCP protocol operation in the Linux operating system
Mestrado
Ciência da Computação
Mestre em Ciência da Computação
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13

Williams, Jacqueline Louise, and jacqueline williams@mcri edu au. "Motor imagery and developmental coordination disorder (DCD)." RMIT University. Health Sciences, 2007. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20080617.141139.

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Developmental Coordination Disorder (DCD) is characterised by impairments to motor control and learning, the cause of which remains unclear. Recently, researchers have used cognitive neuroscientific approaches to explore the basis of poor coordination in children, with one hypothesis suggesting that an internal modelling deficit (IMD) is one of the underlying causes of DCD. The aim of this thesis was to further test the IMD hypothesis using a motor imagery paradigm - the mental rotation of hands. Versions of this task were used in all studies to assess motor imagery ability, with an additional whole-body task used in Studies 2 and 3. Further, an alphanumeric rotation task was used in Studies 1 and 2 to assess visual imagery ability. Studies 1 and 2 provided varying levels of support for the IMD hypothesis. In Study 1, only a subgroup of DCD children performed differently from other children in the study on the hand tasks, but tighter task constraints in Study 2 led to overall group differences between DCD and controls in terms of accuracy. The DCD group were also significantly less accurate than controls in the whole-body task, but there were no group differences in either Study 1 or 2 on the visual imagery task. Interestingly, in Study 2, there was an indication that children with severe levels of motor impairment were less accurate than children with less severe motor impairment, suggesting that motor impairment level could play a role in the severity of motor imagery deficits. Study 3 was designed to explore the impact of motor impairment severity on motor imagery ability further. The results confirmed that children with severe DCD had greater motor imagery impairment than children with mild DCD - children with severe DCD performed less accurately than both controls and those with mild DCD in the hand task with instructions and the controls in the whole-body task. Further, those children with mild DCD were able to respond somewhat to motor imagery instructions, whereas those with severe DCD were not. This study provided support to the IMD hypothesis, though the deficit was shown to be dependent on a number of factors. Chapter 5 presents a reasoned account of these various findings and their implications are discussed. It is concluded that motor imagery deficits are evident in many children with DCD, but more so in children with severe motor impairment. A general imagery deficit was ruled out based on the findings of Studies 1 and 2 which showed that visual imagery processes appear intact in children with DCD. Taken together with previous imagery and IMD studies, and related research on feedforward control in DCD, it is concluded that the deficits in motor imagery observed in this thesis are consistent with the hypothesis that an IMD is one likely causal factor in the disorder, particularly in more severe DCD. The observation of differing response patterns between children with mild and severe forms of DCD has important implications for developing a theory of DCD and for remediation.
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Hanes, Ilana. "Investigating the function of DCC in oligodendrocytes." Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=119762.

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Oligodendrocytes are specialized glial cells in the central nervous system (CNS) that arise in the subventricular zone in the embryonic neural tube, and develop into mature, myelinating cells. During myelination, myelin is divided into distinct axonal domains, and maintenance of these domains is required for the proper transmission of nerve impulses by saltatory conduction. Previously our lab has shown that netrin-1 and its receptor Deleted in Colorectal Cancer (DCC) have several functions in oligodendrocytes: netrin-1 and DCC are required for the migration of oligodendrocyte precursor cells and for the maintenance of the paranodal domain in CNS myelin. Also, our lab has identified fragments of netrin-1 in demyelinated lesions in the CNS. Here, I examine the effects of netrin fragments on DCC signaling, as well as investigate the function of DCC at the paranodes by examining a potential interaction between DCC and glial membrane protein, neurofascin-155 (NF155). With these studies, I have demonstrated that netrin-1 fragments composed of the netrin-1 amino terminal VI and V domains affect the multimerization of DCC, the basis for netrin-1's chemoattractive properties in oligodendrocyte precursor cells. I have also provided evidence that DCC binds NF155 when expressed in HEK293T cells; however analysis of immunoreactive distributions of DCC and NF155 did not demonstrate co-localization. Together, these findings provide novel insights into DCC function during oligodendrocyte development and myelin maintenance.
Les oligodendrocytes sont des cellules spécialisées du système nerveux central (SNC) qui trouvent leur origine dans la zone sous-ventriculaire du tube neural embryonnaire et qui se développent en cellules matures aux capacitées myélinisantes. Au cours de la myélinisation, la myéline est divisée en domaines axonaux distincts, et l'entretien de ces domaines est nécessaire à la bonne transmission de l'influx nerveux par conduction saltatoire. Notre laboratoire a démontré précédemment que la nétrine-1 et le récepteur Deleted in Colorectal Cancer (DCC) ont plusieurs fonctions chez les oligodendrocytes: ils sont requis pour la migration des cellules précurseurs d'oligodendrocytes et pour l'entretien du domaine paranodale dans la myéline. De plus, notre laboratoire a identifié des fragments de la nétrine-1 dans les lésions démyélinisées du SNC. Je vous présente ici mes recherches sur les effets des fragments de nétrine-1 sur la signalisation de DCC, ainsi qu'une étude sur la fonction de DCC au paranodes en examinant une intéraction potentielle entre DCC et la protéine membranaire des cellules gliales, neurofascin-155 (NF155). Mes études démontrent que les fragments de la nétrine-1 contenant uniquement les domaines VI et V affectent la multimérisation de DCC, une caractéristique qui est à la base des propriétés chimiques attirantes de la nétrine-1 dans les cellules précurseurs d'oligodendrocytes. De plus, je démontre que DCC intéragit avec NF155 lorsqu'exprimés dans les cellules HEK293T même si une analyse de la distribution de l'immunoréactivité de DCC et NF155 n'a pas montré de co-localisation. Ensembles, ces résultats fournissent un nouvel aperçu sur la function de DCC durant le développement des oligodendrocytes et l'entretien de la myéline.
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Liu, Jie. "DCD algorithm : architectures, FPGA implementations and applications." Thesis, University of York, 2008. http://etheses.whiterose.ac.uk/1629/.

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In areas of signal processing and communications such as antenna array beamforming, adaptive filtering, multi-user and multiple-input multiple-output (MIMO) detection, channel estimation and equalization, echo and interference cancellation and others, solving linear systems of equations often provides an optimal performance. However, this is also a very complicated operation that designers try to avoid by proposing different sub-optimal solutions. The dichotomous coordinate descent (DCD) algorithm allows linear systems of equations to be solved with high computational efficiency. It is a multiplication-free and division-free technique and, therefore, it is well suited for hardware implementation. In this thesis, we present architectures and field-programmable gate array (FPGA) implementations of two variants of the DCD algorithm, known as the cyclic and leading DCD algorithms, for real-valued and complex-valued systems. For each of these techniques, we present architectures and implementations with different degree of parallelism. The proposed architectures allow a trade-off between FPGA resources and the computation time. The fixed-point implementations provide an accuracy performance which is very close to the performance of floating-point counterparts. We also show applications of the designs to complex division, antenna array beamforming and adaptive filtering. The DCD-based complex divider is based on the idea that the complex division can be viewed as a problem of finding the solution of a 2x2 real-valued system of linear equations, which is solved using the DCD algorithm. Therefore, the new divider uses no multiplication and division. Comparing with the classical complex divider, the DCD-based complex divider requires significantly smaller chip area. A DCD-based minimum variance distortionless response (MVDR) beamformer employs the DCD algorithm for multiplication-free finding the antenna array weights. An FPGA implementation of the proposed DCD-MVDR beamformer requires a chip area much smaller and throughput much higher than that achieved with other implementations. The performance of the fixed-point implementation is very close to that of floating-point implementation of the MVDR beamformer using direct matrix inversion. When incorporating the DCD algorithm in recursive least squares (RLS) adaptive filter, a new efficient technique, named as the RLS-DCD algorithm, is derived. The RLS-DCD algorithm expresses the RLS adaptive filtering problem in terms of auxiliary normal equations with respect to increments of the filter weights. The normal equations are approximately solved by using the DCD iterations. The RLS-DCD algorithm is well-suited to hardware implementation and its complexity is as low as O(N2) operations per sample in a general case and O(N) operations per sample for transversal RLS adaptive filters. The performance of the RLS-DCD algorithm, including both fixed-point and floating-point implementations, can be made arbitrarily close to that of the floating-point classical RLS algorithm. Furthermore, a new dynamically regularized RLS-DCD algorithm is also proposed to reduce the complexity of the regularized RLS problem from O(N^3) to O(N^2) in a general case and to O(N) for transversal adaptive filters. This dynamically regularized RLS-DCD algorithm is simple for finite precision implementation and requires small chip resources.
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16

Basheer, Shamnad. "The invention of an investment incentive for pharmaceutical innovation." Thesis, University of Oxford, 2011. https://ora.ox.ac.uk/objects/uuid:b53d2ab0-dcdd-4adc-8728-cdf32e948df6.

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Pharmaceutical drugs are often hailed as the poster child for the proposition that patents foster accelerated rates of innovation. This sentiment stems, in large part, from the significantly high research and development (R&D) costs endemic to the pharmaceutical sector. I argue that if the role of the patent regime is one of fostering higher amounts of investment in the R&D process, it is better served by a direct investment protection regime, where the protection does not depend upon whether or not the underlying idea behind the drug is 'new' and 'inventive', the two central tenets of patent law. Rather, any drug that successfully makes it past the regulatory filter ought to be entitled to protection, since its discovery and development entail significant investment and risk. Owing to the inadequacy of the current patent regime in appropriately protecting intensive pharmaceutical R&D investments from free-riders, I propose a comprehensive investment protection regime that protects all the investment costs incurred during the drug discovery and development process. Though similar to existing data protection regimes in some respects, it differs in others. Firstly, it enables a recovery of all R&D costs, and not only costs associated with clinical trials. Secondly, unlike patents and data exclusivity which offer uniform periods of protection, it rewards investments in a proportionate manner, wherein drug originators are entitled to protection against free-riders only until such time as they recoup their specific investments and earn a rate of return on investment that is dependent on the health value of the drug. Given that a pure market exclusivity based investment protection regime is likely to foster excessive pricing and subject the market to the dictates of a single firm, I advocate a compensatory liability model based on a novel cost sharing methodology, where follow-on entrants are free to manufacture the drug, but must pay a reasonable amount of compensation to the originator.
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17

SILVA, G. B. "Elaboração e análise de extrato hidrossolúvel de gergelim (Sesamum indicum)." Universidade Federal do Espírito Santo, 2015. http://repositorio.ufes.br/handle/10/4927.

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Made available in DSpace on 2016-08-29T15:36:45Z (GMT). No. of bitstreams: 1 tese_7402_Resumo Dissertação Final - Gisela Benatti Silva - PDF.pdf: 71513 bytes, checksum: 2b900ddb7b27ebe9e1c6bac118df486c (MD5) Previous issue date: 2015-04-10
O objetivo do presente estudo foi elaborar e caracterizar um extrato hidrossolúvel à base de gergelim para ser usado como possível substituto do leite de vaca e extrato de soja. Foi proposto um modelo de cinética de absorção de água durante a etapa de maceração no qual estimou o tempo ideal de batimento do gergelim macerado e se essa etapa influencia no rendimento do produto. Posteriormente com o objetivo de saber a influência do tempo de batimento (0,45 min a 14,55 min) e a concentração do extrato (1,925% a 23,07%) foram avaliadas através de um delineamento composto central rotacional (DCCR), ou seja, um delineamento 22 incluindo 4 ensaios nas condições axiais e 5 repetições no ponto central, totalizando 13 experimentos. Para todos os ensaios do delineamento realizou-se análises de viscosidade, cor, sólidos solúveis totais e rendimento. As mesmas análises foram realizadas em amostras comerciais de leite de vaca e extrato hidrossolúvel de soja com o intuito de comparação. Após a realização dessa etapa foi possível à seleção de algumas amostras para elaboração do extrato hidrossolúvel de gergelim e então realizou-se análises físico-químicas (proteína, cinzas, lipídios, carboidratos) e determinou-se a capacidade antioxidante por ABTS e teor de compostos fenólicos de tais amostras. Quanto à análise de rendimento não houve diferença significativa da quantidade de extrato obtido em diferentes temperaturas de maceração pelo teste de Tukey (p> 0,05). O DCCR foi realizado no programa Statistica e selecionaram-se os ensaios 1, 2, 6, 7, PC (ponto central) que foram as amostras que mais se assemelharam com as amostras comerciais estudadas. Nessas amostras realizou-se as análises físico-químicas além de capacidade antioxidante e compostos fenólicos. O conteúdo de sólidos totais na amostra 6 foi superior as demais amostras, diferindo estatisticamente das demais amostras (p> 0,05). Já para o teor de lipídios, cinzas e proteínas encontrados nas amostras 6 e PC foram maiores que as demais amostras, enquanto a amostra 7 exibiu o menor teor de lipídios e proteínas, considerando que o teor de cinzas das amostras 1, 2 e 7 foram estatisticamente iguais. O teor de carboidratos calculado por diferença foi superior nas amostras 1, 2 e 7 e com o menor valor na amostra 6. Os valores de capacidade antioxidante e compostos fenólicos não se diferenciaram estatisticamente entre si ao nível de 5% de probabilidade. Concluiu-se portanto que a etapa de maceração não influenciou no rendimento do produto final. A partir das análises físico-químicas pode-se concluir que o extrato hidrossolúvel de gergelim em determinadas amostras apresentou um melhor desempenho quanto ao valor nutricional comparado ao extrato de soja.
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18

Naim, Ghassan. "Performance evaluation of the IS-136 DCCH reverse access channel mechanism." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0007/MQ36728.pdf.

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19

Hedlund, Magnus. "Design and construction of a bidirectional DCDC converter for an EV application." Thesis, Uppsala University, Electricity, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-119916.

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A Sliding Mode Control System for a Bidirectional DCDC Converter was designed and a low voltage prototype was constructed. The control system based its decisions solely on the latest available measurements, which improves performance when changing operative quadrant, since no memory needs reinitializing (such as for PI and state prediction methods). A boost control philosophy was presented, based on a current source approximation. The control was found to be stable without steady-state errors when the variance of the input/output dynamics was high.

The target application for the DCDC Converter is an EV (Electric Vehicle) with a flywheel driveline, which puts additional requirements of the converter. Among these are current and voltage control, bidirectionality, and a broad input voltage range.

Simulations were performed in Simulink prior to physical implementation, proving functionality of the proposed control system. The physical implementation of the control was done on a digital signal processor with code compiled from C. A median filter was designed to increase measurement efficiency for the current sensors which had shot-like noise distortions.

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20

Richardson, Emily Sue. "Use of polyhalite mineral as an acidogenic product in the diets of close-up non-lactating dairy cows." Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/98846.

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Polyhalite is a natural mineral that could be fed as an acidogenic product to induce a metabolic acidosis and prevent clinical hypocalcemia in dairy cows after calving. The overall objective of this study was to determine if the use of polyhalite mineral in the diets of pre-partum non-lactating dairy cows was effective as an acidogenic product. We measured the urine pH, dry matter intake, milk yield, and calcium and magnesium concentration of urine and serum in pre-partum and non-lactating dairy cows consuming diets containing a low dose of polyhalite (200 g/cow/day), a high dose of polyhalite (400 g/cow/day), calcium chloride (250 g/cow/day), or no acidogenic product. We hypothesized that including polyhalite mineral as an acidogenic product in the diets of pre-partum and non-lactating dairy cows will reduce urine pH and stimulate calcium metabolism mechanisms. We found that polyhalite effectively reduced urine pH and did not affect dry matter intake, and the stimulation of calcium metabolism was observed through an increase of calcium output in urine. In conclusion, feeding polyhalite mineral is an effective means for inducing metabolic acidosis without reducing dry matter intake. Based on these results, polyhalite should be fed at a dose of 400 g or more per cow per day to reduce urine pH.
Master of Science in Life Sciences
Low blood calcium concentration, also known as hypocalcemia, is one of the common metabolic disorders that affect dairy cows transitioning from the pre-partum to post-partum period. Reducing the dietary cation anion difference (DCAD) in cows during the close-up period is known to effectively reduce the probability of cows developing hypocalcemia after calving. Polyhalite is a natural mineral that could be fed as an acidogenic product to induce a metabolic acidosis and prevent hypocalcemia in dairy cows after calving. The overall objective of this study was to determine if the use of polyhalite mineral in the diets of pre-partum and non-lactating dairy cows was effective as an acidogenic product. We evaluated the urine pH, dry matter intake, milk yield, and calcium and magnesium concentration of urine and serum in pre-partum and non-lactating dairy cows consuming diets containing a low dose of polyhalite (200 g/cow/day) , a high dose of polyhalite (400 g/cow/day), calcium chloride (250 g/cow/day), or no acidogenic product. We hypothesized that including polyhalite mineral as an acidogenic product in the diets of pre-partum and non-lactating dairy cows will reduce urine pH and stimulate calcium metabolism mechanisms. We found that polyhalite effectively reduced urine pH and did not affect dry matter intake, and the stimulation of calcium metabolism was observed through an increase of calcium output in urine. In conclusion, feeding polyhalite mineral is an effective means for inducing metabolic acidosis without reducing dry matter intake. Based on these results, polyhalite should be fed at a dose of 400 g or more per cow per day to reduce urine pH.
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21

Wells, Anna. "Student mobility and competence development in higher education : a study of Latvian students at English universities." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:6c13c889-dccb-418b-a811-2c341842873e.

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This research examines experiences of Latvian students pursuing undergraduate degrees at universities in England. Working with this population positions this research in the subject area of International Student Mobility (ISM). As a relatively new subject ISM is still developing suitable concepts, methodological practices and scientific terminology. This presents a challenge but also calls for more in-depth work in the area. As an exploratory study this research answers this call and proposes new directions in the development of ISM as a research field. ISM is particularly interesting in the context of contemporary Europe where student mobility is considered as a vehicle of human capital across national borders. As such student mobility contributes to further internationalization of the European labour force and facilitates development of the knowledge-based economy. Finding out what students gain from university education abroad remains a topic of scientific debate. This research focuses on the practical but complicated part of Higher Education: competence development. The review of the literature reveals that the topic of competence development in Higher Education has been in and out of researchers’ favour, but it has not been examined in the international context. This consideration is timely as more and more students seek education abroad and competences developed at foreign universities are transferred across borders. This research is based on in-depth interviews with Latvian students in England, their family members and friends both in Latvia and in England. Interviewing family and friends enriched the self-reporting accounts of the students, thus capturing a more holistic representation of the students’ experiences. In addition, accounts of the students’ network representatives from England and from Latvia positioned this research in the international social networks of the students. This research finds that international social networks are the natural and necessary environments in which mobility of students takes place and argues that it needs to be studied with consideration to these under-researched environments. This study also proposes a longitudinal focus. The main participants of this research, the students, were interviewed three times over three years, which goes beyond most research studies on student mobility. The analysis of the interview responses relies on multiple iterations between the literature and the data. The findings demonstrate that degree-seeking students develop competences that can be grouped in three main areas: gaining access to university education in England, socio-cultural acculturation and academic acculturation. In each of these areas students develop specific skills and abilities that support the three areas of competences. The development of the skills, abilities and competences is explained through a model created by Noel Burch for Gordon Training International (GTI). The model outlines four stages of development that progress from the level of unconscious incompetence, to conscious incompetence, to conscious competence and to unconscious competence.
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22

Bigdeli, Sam, and Filip Bengtsson. "Portfolio Optimization : A DCC-GARCH forecast with implied volatility." Thesis, Linnéuniversitetet, Institutionen för ekonomistyrning och logistik (ELO), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-85992.

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This thesis performs portfolio optimization using three allocation methods, Certainty Equivalence Tangency (CET), Global Minimum Variance (GMV) and Minimum Conditional Value-at-Risk (MinCVaR). We estimate expected returns and covariance matrices based on 7 stock market indices with a DCC-GARCH model including an ARMA (1.1) process and an external regressor of an implied volatility index (VIX). We then simulate returns using a rolling window of 500 daily observations and construct portfolios based on the allocation methods. The results suggest that the model can sufficiently estimate expected returns and covariance matrices and we can outperform benchmarks in form of equally weighted and historical portfolios in terms of higher returns and lower risk. Over the whole out-of-sample period the CET portfolio yields the highest mean returns and GMV and MinCVaR can significantly lower the variance. The inclusion of VIX has marginal effects on the forecasting accuracy and it seems to impair the estimation of risk.
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Madrid, Cabezas Francisco Javier. "Integración y evolución de sistemas de información del DCC." Tesis, Universidad de Chile, 2017. http://repositorio.uchile.cl/handle/2250/148981.

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Ingeniero Civil en Computación
Desde hace varios años, el Departamento de Ciencias de la Computación (DCC) de la Universidad de Chile ha venido desarrollando sus sistemas de información como si fueran islas. Estos sistemas apoyan principalmente la gestión de actividades académicas, docentes y económico-financieras del DCC. Aunque esta infraestructura de software ha funcionado relativamente bien, la estrategia de desarrollo de sistemas desacoplados limita el crecimiento de dicha infraestructura de cara al futuro. Por esa razón el DCC ha decidido integrar estas islas, tanto a nivel de datos como de servicios, para permitir un desarrollo más armónico y controlado de sus sistemas de información. Se espera que esta integración facilite especialmente el reuso de información, manteniendo una única fuente de verdad para las distintas áreas de negocio (pregrado, postgrado, educación continua, investigación, etc.). Este trabajo de memoria realizó una prueba de concepto que abordó no sólo la integración de dos sistemas de información del DCC, sino también la reingeniería de uno de ellos y el desarrollo completo del otro. Las aplicaciones en cuestión son el Sistema Administrador de Recursos (SAR) y el Sistema Administrador de Noticias y Eventos (SANE). Para llevar a cabo la integración de estos sistemas se diseñó e implementó una arquitectura de microservicios que es capaz de contener a las aplicaciones críticas del Departamento. Apoyándose en dicha arquitectura se modificó y extendió el sistema SAR, agregándole por ejemplo funcionalidad para permitir la administración de puestos de trabajos de alumnos de postgrado y profesores visitantes. Por otra parte, el proceso de reservas de recursos (por ejemplo, salas de reuniones) se independizó de las secretarias, permitiendo que académicos y funcionarios puedan hacer reservas según su rol. La nueva versión del sistema SAR está actualmente en producción. Por otra parte, se diseñó e implementó un nuevo sistema de software, el cual permite mantener y gestionar las noticias y eventos del Departamento (por ejemplo, charlas, defensas de tesis, etc.). Éste permite además alimentar automáticamente otros recursos de entrega de información del Departamento; por ejemplo, su página Web oficial. El sistema SANE también adhiere a la arquitectura de microservicios definida, y permite la interacción con el SAR a través de una API (Application Programming Interface). El proyecto piloto que buscaba la integración de ambos sistemas a través de una arquitectura de microservicios resultó exitoso, pues no sólo se alcanzaron los objetivos iniciales, sino que además los usuarios finales se mostraron muy satisfechos con las soluciones obtenidas. Este piloto muestra un camino para que en adelante se integren otros sistemas a la nueva infraestructura de software del DCC, independientemente de que estas aplicaciones sean nuevas o legadas. Las nuevas aplicaciones deberán contemplar la intercomunicación con la infraestructura creada, utilizando mecanismos de autenticación adecuados para garantizar la seguridad de sus operaciones. En resumen, más allá de las ventajas propias de contar con más y mejores servicios de software para apoyar las operaciones del Departamento, este trabajo de memoria buscó determinar la factibilidad y el esfuerzo requerido para integrar los sistemas del DCC a través de una arquitectura de microservicios; y el resultado obtenido fue altamente positivo.
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Gagliardi, Anna. "A new, environmentally friendly approach towards the synthesis of epoxy functionalized poly-DCPD." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/19196/.

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Epoxy resins are thermosetting resins with excellent mechanical properties, high adhesiveness to many substrates, good thermal stability and chemical resistances, high tensile strength and modulus, and ease of handling and processability. Currently epoxy resins are very popular as fiber-reinforced materials, general-purpose adhesives, high-performance coatings, paints and encapsulating materials. During the last decades, demand for material systems with precise control over multiple properties has increased, as well as the necessity to find new sustainable processes for their manufactory. Thanks to a collaboration between the German company Rutgers and professor Raveendran of the University of Amsterdam, the work presented here was focused on a novel, environmentally friendly path for the achievement of epoxy functionalized poly-DCPD. Reaction of epoxidation of DCPD with hydrogen peroxide, catalyzed by various metal oxides, was studied and optimized in view of a future polymerization of the functionalized monomers. Direct epoxidation of poly-DCPD was also attempted.
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Doria, Priscila Lôbo Gonçalves. "Avaliação de desempenho de variantes dos Protocolos DCCP e TCP em cenários representativos." Universidade Federal de Sergipe, 2012. https://ri.ufs.br/handle/riufs/3332.

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The Datagram Congestion Control Protocol (DCCP) is a prominent transport protocol that has attracted the attention of the scientific community for its rapid progress and good results. The main novelty of DCCP is the performance priority design, as in UDP, however with congestion control capabilities, as in TCP. Literature about DCCP is still scarce and needs to be complemented to gather enouth scientific elements to support new research properly. In this context, this work joins the efforts of the scientific community to analise, mensure, compare and characterize DCCP in relevant scenarios that cover many real world situations. Three open questions were preliminarly identified in the literature: How DCCP behaves (i) when fighting for the same link bandwidth with other transport protocols; (ii) with highly relevant ones (e.g., Compound TCP, CUBIC) and (iii) fighting for the same link bandwidth with Compound TCP and CUBIC, adopting multimedia applications (e.g., VoIP). In this work, computational simulations are used to compare the performance of two DCCP variants (DCCP CCID2 and DCCP CCID3) with three highly representative TCP variants (Compound TCP, CUBIC and TCP SACK), in real world scenarios, including concurrent use of the same link by protocols, link errors and assorted bandwidths, latencies and traffic patterns. The simulation results show that, under contention, in most scenarios DCCP CCID2 has achieved higher throughput than Compound TCP or TCP SACK. Throughout the simulations there was a tendency of DCCP CCID3 to have lower throughput than the other chosen protocol. However, the results also showed that DCCP CCID3 has achieved significanly better throughput in the presence of link errors and higher values of latency and bandwidth, eventualy outperforming Compound TCP and TCP SACK. Finally, there was a tendency of predominance of CUBIC´ throughtput, which can be explained by its aggressive algorithm (i.e., non-linear) of return of the transmission window to the previous value before the discard event. However, CUBIC has presented the highest packet drop and the lowest delivery rate.
O Datagram Congestion Control Protocol (DCCP) é um proeminente protocolo de transporte que vem atraindo a atenção da comunidade científica pelos seus rápidos avanços e bons resultados. A principal inovação do DCCP é a priorização de desempenho, como ocorre com o UDP, mas com capacidade de realizar controle de congestionamento, como ocorre com o TCP. Entretanto, a literatura sobre o DCCP ainda é escassa e necessita ser complementada para trazer elementos científicos suficientes para novas pesquisas. Neste contexto, este trabalho vem se somar aos esforços da comunidade científica para analisar, mensurar, comparar e caracterizar o DCCP em cenários representativos que incorporem diversas situações de uso. Identificaram-se então três questões alvo, ainda em aberto na literatura: qual é o comportamento do DCCP (i) quando disputa o mesmo enlace com outros protocolos de transporte; (ii) com protocolos de transporte relevantes (e.g., Compound TCP, CUBIC) e (iii) em disputa no mesmo enlace com o Compound TCP e o CUBIC, utilizando aplicações multimídia (e.g., VoIP). Neste trabalho, simulações computacionais são utilizadas para comparar duas variantes do DCCP (CCID2 e CCID3) a três variantes do TCP (Compound TCP, CUBIC e TCP SACK), em cenários onde ocorrem situações de mundo real, incluindo utilização concorrente do enlace pelos protocolos, presença de erros de transmissão no enlace, variação de largura de banda, variação de latência, e variação de padrão e distribuição de tráfego. Os resultados das simulações apontam que, sob contenção, na maioria dos cenários o DCCP CCID2 obteve vazão superior à do Compound TCP, do DCCP CCID3 e do TCP SACK. Ao longo das simulações observou-se uma tendência do DCCP CCID3 a ter vazão inferior à dos demais protocolos escolhidos. Entretanto, os resultados apontaram que o DCCP CCID3 obteve desempenho significativamente melhor na presença de erros de transmissão e com valores maiores de latência e de largura de banda, chegando a ultrapassar a vazão do DCCP CCID2 e do TCP SACK. Por fim, observou-se uma tendência de predominância do protocolo CUBIC no tocante à vazão, que pode ser determinada pelo seu algoritmo agressivo (i.e., não-linear) de retorno da janela de transmissão ao valor anterior aos eventos de descarte. Entretanto, o CUBIC apresentou o maior descarte de pacotes e a menor taxa de entrega.
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SILVA, Iasmim Lucas da. "Otimização, purificação e caracterização de l-asparaginase da rizosfera de caesalpinia pyramidalis produzida por pseudomonas sp. e identificação morfológica e molecular da bactéria." Universidade Federal de Pernambuco, 2016. https://repositorio.ufpe.br/handle/123456789/18528.

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Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2017-04-10T17:01:48Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Iasmim Lucas da Silva.pdf: 2916095 bytes, checksum: c23cab722c74173251220dd40ba0f0cc (MD5)
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A L-asparaginase (E.C. 3.5.1.1) é essencial para um curso normal do ciclo celular, estando presente em bactérias, fungos, animais e plantas e não é encontrada em seres humanos. Importante para o tratamento da leucemia linfoblástica aguda dentre outras doenças leucêmicas e a doença de Hodgkin. As Pseudomonas são ocorrentes no solo e água, apresentam a capacidade de produzir enzimas, como é o caso da L-asparaginase do Tipo I e II. Com isso, o objetivo deste trabalho foi obter melhores parâmetros para otimização, purificação parcialmente da L-asparaginase excretada por Pseudomonas sp. isolada da rizosfera da Caesalpinia. pyramidalis. No presente estudo visando otimizar a produção do complexo de L-asparaginase foi realizado um planejamento experimental central composto (23) com 4 pontos centrais, sendo as variáveis pH (4, 7 e 10), temperatura (30°C, 40°C e 50°C) e concentração da L-asparagina (0,2%, 0,5% e 0,8%) estudadas. Posteriormente realizou-se a análise estatística das variáveis e a análise da variância (ANOVA) dos resultados obtidos que foram avaliados através do programa Statistica, versão 7.0 (StatSoft Co., USA). Em seguida, realizou-se a purificação da enzima L-asparaginase excretada por Pseudomonas sp. através da técnica de cromatografia de troca iônica e uma eletroforese SDS-PAGE. Posteriormente, foi realizada a caracterização da enzima purificada, avaliando os efeito e estabilidades em diferentes valores de pH e temperaturas, por fim a enzima em diferentes substratos e íons. Finalizando foram efetuadas as identificações morfológica e molecular da bactéria, utilizando o Microscópio Eletrônico de Varredura (MEV) e a nível de espécie usou-se o primer 16 S respectivamente. Os resultados obtidos no procedimento de otimização da atividade de L-asparaginase foram obtidos nos ensaios com concentração de L-asparagina a 0,8%, pH 4 e temperatura de 30°C, com valores de atividades 0,5604 U/mL e 0,0632 mg de proteína/mL, respectivamente. Os melhores dados da cromatografia de troca iônica mostraram que das 57 frações coletadas, as de melhor atividade para L-asparaginase, foram as frações de valores 1,1412 U/mL e 1,1417 U/mL, com um rendimento de 0,64% e 18,6 U/mg de atividade específica. Realizou-se uma eletroforese PAGE-SDS para obter o peso molecular da proteína, apresentando como peso molecular de 32 kDa. Na caracterização enzimática, a enzima se mantem estável em pH 7, em relação a temperatura, tivemos a melhor estabilidade 30 °C, a L-asparaginase apresentou melhor efeito nos substratos L-asparagina seguido da L-glutamina e por fim o nitrato de sódio (NaNO3), cloreto de Mercúrio (HgCl2), cloreto de magnésio (MgCl2) e ureia apresentaram os melhores efeitos de íons. Em relação à identificação bacteriana encontrou-se colônias em forma de bastonetes curtos, com longos flagelos e a nível de espécie foi denominada com sendo Pseudomonas aeruginosa. Portanto, os resultados obtidos da L-asparaginase caracterizada, isolada da P. aeruginosa, mostraram resultados significativos e extremamente importantes para a indústria biotecnológica, apresentando assim a viabilidade e confiabilidade do estudo realizado.
L-asparaginase (E.C. 3.5.1.1) is essential for the normal course of cell cycle being present in bacteria, fungi, animals and plants and is not found in humans. Important for the treatment of acute lymphoblastic leukemia among other leukemic disease and Hodgkin's disease. The Pseudomonas are occurring in soil and water, have the capacity to produce enzymes, such as L-asparaginase Type I and II. Thus, the aim of this study was to obtain the best parameters for optimization, purification part of L-asparaginase secreted by Pseudomonas sp. isolated from the rhizosphere of Caesalpinia pyramidalis. In the present study to optimize the production of L-asparaginase complex was performed a central experimental design compound (23) with four central points and the variables pH (4, 7 and 10), temperature (30°C, 40°C and 50°C) and concentration of L-asparagine (0,2%, 0,5% and 0,8%) studied. Later there was the statistical analysis of the variables and analysis of variance (ANOVA) of the results that were evaluated through Statistica, version 7.0 (StatSoft Co., USA). Then there was the purification of L-asparaginase enzyme secreted by Pseudomonas sp. by ion exchange chromatography technique and SDS-PAGE electrophoresis. Afterwards, the characterization of the purified enzyme was carried out to evaluate the effect and stability at different pH values and temperatures, and finally the enzyme on different substrates and ions. Finalizing were made the morphological and molecular identification of bacteria using the Scanning Electron Microscope (SEM) and the kind of level we used the primer 16S respectively. The results of the optimization procedure for L-asparaginase activity in the assays were obtained with a concentration of L-asparagine to 0,8%, pH 4 and 30°C, with activity values 0,5604 U/mL and 0,0632 mg of protein/mL, respectively. The best data ionic exchange chromatography showed that the 57 collected fractions, the best activity to L-asparaginase were fractions values 1,1412 U/mL and 1,1417 U/mL, with a yield of 0,64 % and 18,6 U/mg specific activity. We performed a SDS-PAGE electrophoresis for the molecular weight of the protein, presenting as molecular weight of 32 kDa. In the enzyme characterization, the enzyme is stable at pH 7 with respect to temperature had better 30 °C stability, L-asparaginase had a better effect on the L-asparagine substrate followed by L-glutamine and finally sodium nitrate (NaNO3), mercury chloride (HgCl2), magnesium chloride (MgCl2) and urea showed the best effects ions. Regarding the bacterial identification met colonies in the form of short rods with flagella long and species level was named as being Pseudomonas aeruginosa. Therefore, the results of characterized L-asparaginase, isolated from P. aeruginosa, showed significant results and extremely important for the biotechnology industry, thus presenting the viability and reliability of the study performed.
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Tritsch, Nicolas X. "Netrin-1 signaling through DCC enhances synapse number and function." Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=81446.

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Actin-based changes in filopodia dynamics and spine morphology play an important role in initiating synapse formation and mediating synaptic plasticity. During embryonic development, the guidance cue netrin-1 signals through Deleted in Colorectal Cancer (DCC) receptors to modulate actin cytoskeleton dynamics, enhancing the formation and motility of filopodia. We recently reported that netrin-1 and DCC continue to be expressed in the adult spinal cord, but their function remains elusive. Here, we report that netrin-1 and DCC are expressed in adult cortical and hippocampal neurons, where they distribute to synaptic sites. In primary cortical neuron cultures, while netrin-1 is restricted to dendrites, DCC localizes to both axonal and dendritic compartments. We find that netrin-1 increases the density of axonal and dendritic filopodia and branches in a DCC-dependent manner. We demonstrate that, although dispensable for synapse formation and maintenance, netrin-1-DCC signaling enhances the number and efficacy of synaptic sites in vitro. These observations suggest a novel role for netrin-1 and DCC in synaptogenesis and synaptic plasticity.
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Tcherkezian, Joseph. "Phosphoregulation of CdGAP and DCC, proteins involved in actin dynamics." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=102215.

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The Rho GTPases are members of the Ras superfamily of small monomeric GTP binding proteins that regulate multiple cellular processes affecting both cell proliferation and cytoskeletal dynamics. They are positively and negatively regulated by the guanine nucleotide exchange factors (GEFs) and the GTPase-activating proteins (GAPS), respectively. In principle, extracellular signals such as growth factors and other agents bind to plasma membrane receptors and modulate Rho GTPase function through intracellular mechanisms that affect GEF or GAP activities. There is now compelling evidence that both receptors and cytoplasmic proteins implicated in Rho GTPase signaling are modulated by post-translational modifications such as phosphorylation.
CdGAP (Cdc42 GTPase- activating protein) is a negative regulator of Rac1 and Cdc42 and the netrin-1 receptor DCC (deleted in colorectal cancer) is an upstream activator of these GTPases during axon guidance. To date, very little is known about the biochemical regulation of these two proteins. Given that CdGAP protein migrates higher than its expected molecular weight and contains a number of consensus phosphorylation sites for different kinases, and that the DCC ortholog in C. elegans UNC-40 is tyrosine phosphorylated, it is likely that both proteins are regulated through mechanisms involving phosphorylation.
In the first part of this thesis, we have demonstrated that CdGAP phosphorylation in vivo is stimulated by external cues that activate the Ras-MEK-ERK pathway. We also found that CdGAP is phosphorylated in vivo on serine, threonine but not tyrosine residues. Phosphorylation of Thr776 by ERK and that this phosphorylation is important in regulating CdGAP's activity towards Rac1.
In the second part, we found that the human ortholog of CdGAP is also active both in vitro and in vivo on Cdc42 and Rac1 but not RhoA. Furthermore, we found that the human protein is also highly phosphorylated in vivo on serine and threonine residues but not tyrosine.
In the last part, we have combined classical biochemical approaches and the dissection of rat primary commissural neurons and found that DCC is phosphorylated in vivo upon netrin-1 stimulation on serine, threonine and tyrosine residues. We have also found that the phosphorylation and function of DCC in axon outgrowth and guidance is mainly regulated by the Src family tyrosine kinases.
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29

Liang, Zijie. "Evaluation and Optimization of ETSI DCC Reactive Approaches for Platooning." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-247924.

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IEEE802.11p is considered as de facto standard for road communication. However, channel congestion is still the main challenge of IEEE802.11p based vehicular networks. Target to solve this issue, European Telecommunication Standards Institute (ETSI) has standardized a set of Decentralized Congestion Control (DCC) mechanisms in which mainly provide reactive and adaptive methods to mitigate communication channel congestion issue. Many efforts have been carried out over these years in order to solve this problem. Most of the results show that the DCC framework is capable of Channel Load (CL) control to some extend. Platooning system is one of these topics which needs to achieve reliable CL control, especially when there are large amount of vehicles communicating on the road. It is a pity that there are few papers of investigating on DCC framework for Platooning channel congestion control. For this purpose, we focus on investigating DCC reactive control approaches, aiming to provide comprehensive insights of how DCC framework transmission parameters, i.e. message generation rate, transmission power and datarate, will impact on the stability of Platooning system. Besides, for each instance of transmission parameter, we target to optimize the parameter, and propose more stable control algorithms by running repetitive simulations. According to our results, the method of adjusting transmission power has the best benefits.
IEEE802.11p anses vara de facto-standard för vägkommunikation. Kanalstockning är dock fortfarande den största utmaningen för IEEE802.11pbaserade fordonstrafik. Målet för att lösa detta problem har standardiserat ett antal decentraliserade Congestion Control-mekanismer (DCC), där det europeiska telekommunikationsstandardinstitutet (ETSI) grundat sig på reaktiva och adaptiva metoder för att mildra problem med överbelastning av kommunikationskanaler. Många ansträngningar har gjorts under dessa år för att lösa detta problem. De flesta resultaten visar att DCC-ramverket i viss utsträckning kan hantera kanalbelastning (CL). Platonering är ett av dessa ämnen som behöver uppnå tillförlitlig CL-kontroll, särskilt när det finns stora mängder fordon som kommunicerar på vägen. Det är synd att det finns få dokument att undersöka om DCC-ramverket för Platooning kanalöverbelastningskontroll. För detta ändamål undersöker vi särskilt DCC-reaktiva kontrollmetoder, som syftar till att ge omfattande insikter om hur DCCramöverföringsparametrar, dvs meddelandegenskapshastighet, överföringseffekt och datarat, kommer att påverka stabiliteten hos Platooningsystemet. För varje instans av överföringsparametern riktar vi dessutom till att optimera parametern och föreslå mer stabila kontrollalgoritmer genom att köra repetitiva simuleringar. Enligt våra resultat har metoden för justering av överföringseffekt de bästa fördelarna.
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Sepúlveda, Guzmán Paulina Andrea. "Reingeniería del Sistema de Registro de Publicaciones Científicas del DCC." Tesis, Universidad de Chile, 2008. http://repositorio.uchile.cl/handle/2250/104922.

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La estructura y el funcionamiento de las organizaciones educacionales se han visto afectadas por la constante búsqueda de la excelencia académica. Una reestructuración del personal, cambios en el organigrama, nuevas mallas curriculares, incorporación de herramientas de apoyo son medidas adoptadas con el fin de lograr el objetivo de la excelencia académica. Últimamente se ha venido desarrollando un nuevo y cada vez más importante factor competitivo: generar, difundir y poner a disposición de todo el conocimiento en una organización. El conocimiento ya no es un recurso más de la organización, sino que, con motivo de la evolución de la sociedad industrial a la sociedad de la información o sociedad del conocimiento, se ha convertido en uno de los principales factores de producción. Es por esto la creciente necesidad de generar herramientas tecnológicas que permitan administrar y gestionar de la mejor manera este conocimiento, el Departamento de la Ciencias de la Computación de la Facultad de Ciencias Físicas y Matemáticas de la Universidad de Chile, no esta ajeno a esta necesidad de administrar la información y conocimiento. En particular la información y conocimiento que requiere administrar el Departamento, es la de la producción investigativa de los académicos y el uso de fondos de incentivos a esta producción. Para lograr este objetivo esta memoria tiene como objetivo principal la de generar una herramienta Web que permita automatizar la gestión de las publicaciones del Departamento y la administración de los fondos de incentivo asociados, esta actividad involucra tanto a los académicos como a personal administrativo del Departamento, como área de investigación, contabilidad y dirección. Esta herramienta tiene como finalidad entregar una visión completa del estado de las publicaciones, para cada uno de los involucrados: Académicos, publicación aceptadas y acreditadas en el Departamento, estado de fondos de incentivos y puntaje Coordinador de Investigación, vista completa de la producción investigativa de los académicos, y administración de los fondos de incentivo. Contabilidad, gestión del uso de los fondos de incentivos Dirección, visión completa y global de la producción investigativa de los académicos y gestión de los fondos de incentivo.
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31

Creveaux, Marion. "Implication de deux partenaires de DCC dans le développement et la tumorigenèse." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1171.

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DCC est un récepteur transmembranaire ayant pour ligand la nétrine-1. DCC appartient à la famille des récepteurs à dépendance, qui ont la particularité de ne pas rester inactifs en absence de ligand mais, au contraire, d'induire activement l'apoptose lorsqu'ils sont dans un état non lié, ce qui explique leur fonction suppresseur de tumeur. Mon travail de thèse s'est articulé autour de deux axes de recherche: Axe 1 : Implication du couple DCC/nétrine-1 dans la lymphomagenèse. Nous avons montrer que l'expression du couple DCC/nétrine-1 est dérégulée dans les lymphomes du manteau (LM) ainsi que dans les lymphomes diffus à grandes cellules B (LDGC-B) : l'expression de la nétrine-1 est augmentée dans les LM et les LDGC-B de type ABC, alors que l'expression de DCC est diminuée dans les LDGC-B de type GC. Sur le plan thérapeutique, rétablir l'apoptose induite par DCC en bloquant l'interaction avec son ligand nétrine-1 induit une diminution du volume tumoral dans un modèle de xénogreffe. Le couple DCC/nétrine-1 pourrait également jouer un rôle dans le développement des lymphomes extranodaux. Axe 2 : Caractérisation fonctionnelle de la protéine ADAMTSL-1.L'orthologue de DCC chez C. elegans, UNC-40 interagit fonctionnellement avec la protéine MADD-4 lors de la mise en place des jonctions neuromusculaires. Nous n'avons pas établi l'existence d'une telle connexion entre DCC et l'orthologue de MADD-4 chez les Mammifères, ADAMTSL1. La fonction d'ADAMTSL1 étant inconnue, nous avons utilisé différents systèmes in vitro et in vivo, dont un modèle murin invalidé constitutivement pour ce gène, pour déterminer la fonction de cette protéine matricielle, notamment dans les tissus musculaires et cartilagineux
DCC is a tramsmembrane protein, receptor of netrin-1. DCC belongs to the dependence receptor family, which have a dual functionality. Indeed, they are not inactive when not bound by their ligand but instead they actively induce apoptosis thus explaining that they are tumor suppressors. My PhD project contains 2 axes :Axe 1 : Involvement of DCC/netrin-1 during lymphomagenesis. We demonstrated that the gene expression of DCC and netrin-1 is deregulated in mantle cell lymphoma (MCL) and in diffuse large b cell lymphoma (DLBCL) : netrin-1 expression is upregulated in MCL and Activated B-Cell DLBCL. On the opposit, DCC expression is downregulated in Germinal Centre DLBCL. From a therapeutical point of view, reinducing DCC's apoptotis by blocking its interaction with netrin-1 triggers tumor volum in a xenograft model. DCC-netrin-1 might also be involved in extra-nodal lymphoma development. Axe 2 : Functional caracterization of ADAMTSL1.DCC's ortholog in C. elegans, UNC-40, functionnaly interacts with the protein MADD-4 during the setting up of neuromuscular junctions. We did not find any such connexion between DCC and MADD-4's ortholog in mammals, ADAMTSL1. The function of ADAMTSL1 is unknown and we used different in vitro and in vivo models including a mouse model invalidated for this gene to unravel the function of this matricial protein, notably in muscular and cartilaginous tissus
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32

Wallberg, Alexander. "Design and construction of a bidirectional DC/DC converter." Thesis, Uppsala universitet, Elektricitetslära, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-385240.

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A four quadrant general single-phase bi-directional DC/DC converter was designed and constructed for high effect systems. The target application for the DC/DC converter was to be used to transfer energy between different energy storages, a miniature DC power grid and the high voltage AC power city grid. The converter is capable of step-up and step-down operations in both directions i.e. it is bi-directional at varying voltage levels. Different DC/DC topologies were investigated, and thereafter simulations were performed in LTspice and Simulink to ensure its capabilities and functionalities. The result of the simulations was a two layered PI-regulator, controlling both the external DC-grid voltage and inductor current through the converter. Once a suitable topology and control strategy was found, a suitable power transistor investigated and a PCB driver card were developed with KiCad. The final converter is capable to seamlessly change between its four modes and controlling voltages up to 1200 V and currents up to 200 A.
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33

Chisholm, A. M. "Oxford City PCG and PCT : a case study of collaboration." Thesis, Oxford Brookes University, 2007. http://radar.brookes.ac.uk/radar/items/c8b866a0-5bf4-b06a-dcfd-3d59e8093840/1.

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In 1997 the New Labour government instigated a period of radical reform for the National Health Service, a key element of which was the establishment across England of Primary Care Groups (PCGs), which subsequently became Primary Care Trusts (PCTs). These were local statutory governance bodies with responsibility to deliver and develop primary care and to improve the health of their local population: complex functions requiring collaboration with a range of organisations and agencies. The central aim of this study was to investigate whether and how PCG/Ts developed and facilitated collaboration within primary care, and between it and other NHS and non-NHS bodies, and to identify factors which enabled and inhibited collaboration. Using a theoretical framework which draws on a critical realist tradition, an approach was adopted to the analysis of organisational change which was attentive not only to rational, incremental processes of change but which took into account the political, cultural and economic context in which PCG/Ts operated. A key element of this context was the strong resemblance between New Labour's prominent `third way' discourse of collaboration and the defining characteristics of a network mode of governance: trust, loyalty, reciprocity and voluntariness. Inductive and deductive approaches were combined to test and develop theory about the interactions between context and organisational form, using multiple qualitative methods within a longitudinal nested case study. The study demonstrated that the locality-wide base of PCG/Ts, their explicit health improvement remit, budgetary arrangements and the presence of clinicians on their governing bodies were aspects of their organisational forms which equipped them to facilitate collaboration. However, over time, certain contradictions became apparent in New Labour's approach to organising the NHS which undermined many of the PCG/T's collaborative processes. This thesis argues that the alignment of the third way discourse with a network mode of governance exemplified 'symbolic politics. ' What was presented as a rational response to complex social problems and fragmentation of public services, was in fact largely a pragmatic political manoeuvre designed to distance itself from the perceived failure of previous administrations' hierarchy and market modes of governance.
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34

Schweitzer, C. "Strategies of intervention in protracted violent conflicts by civil society actors : the example of interventions in the violent conflicts in the area of former Yugoslavia." Thesis, Coventry University, 2009. http://curve.coventry.ac.uk/open/items/f10df296-dcc0-062b-8ba7-85d3f28687e7/1.

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This thesis seeks to contribute to the understanding of conflict intervention in protracted violent conflicts by studying the activities of civil society actors in regard to the conflicts in what was Yugoslavia until 1991. A very broad understanding of ‘intervention’ is used for this purpose that includes all kinds of activities that relate to the conflicts. Based on a survey of activities in the period between 1990 and 2002, a framework for categorising and describing these interventions is applied according to basic functions in four ‘grand strategies’ of ‘peace-making’, ‘peace-keeping’, ‘peacebuilding’, and ‘information, support, protest and advocacy’, with a total list of about 230 instruments of conflict intervention identified. The study concludes that civil society actors played three different basic roles: They complemented the work of state actors, they were the avant-garde for approaches, strategies and methods that later became ‘mainstream’ in conflict intervention, and in some cases, they were able to control or correct actions by governments through advocacy or direct action. The development of instruments of civil conflict transformation received a massive boost through this engagement in the 1990s. The study supports the position taken recently by some researchers making comparative studies of cases of conflict intervention regarding the limited role played by dialogue and reconciliation work in regard to dealing with the overall conflicts: In spite of ‘reconciliation’ and inter-ethnic cooperation being at the core of the vast majority of all projects and programmes undertaken in the area, indicators of real impact regarding an overall positive change in society and prevention of future violence seem to be rather weak. The study further observes that there was a social movement developed relating to former Yugoslavia in many Western countries that in a hitherto unknown way combined traditional methods of protest and advocacy with concrete work in the field.
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35

Tabiš, Peter. "Dynamické modely oceňovania aktiv." Master's thesis, Vysoká škola ekonomická v Praze, 2013. http://www.nusl.cz/ntk/nusl-199290.

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Field of examination is theoretical and empirical review of dynamic CAPM models that assume non constant volatility and correlation. In other words time evolution is considered in estimation process. As theoretical basement is recommended to be R. Engle's (Dynamic Conditional Beta) research and other sources.
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36

Jerauld, Joy Meredith. "Predicting Early Academic Achievement: An Investigation of the Contribution of Executive Function." Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/338873.

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This study investigated the important question of whether pupils' executive functions (EF) predict early academic achievement. Current conceptualizations suggest that developmental trends in EF can be measured in young children and that EF may play an important role in predicting academic achievement and school readiness. To date, however, there is little empirical support for this assertion. This study explored EF skills of 3- to 5 year-olds using the Dimensional Change Card Sort Task (DCCS). The first objective was to determine if EF indeed predicts math, reading, and writing achievement in 3- to 5-year-olds. The second objective was to determine if EF's prediction of academics occurs independent of the contribution made by general ability (e.g., Battelle motor and language subdomains). The third objective was to determine if the contribution of EF remains uniform across the age span. Consequently, existing data from 969 participants between 54 to 71 months was used. This consisted of scores on the DCCS as well as the Phonological Awareness Literacy Screening (PALS) to measure early reading and writing skills, the Test of Early Math Ability -Third Edition (TEMA-3) to measure early math skills, and sections of the Battelle Developmental Inventory 2nd Edition (BDI- 2) to measure general development. A positive relationship between EF and early math, reading, and writing skills was found. Also EF, as measured by the DCCS, contributed a significant portion of variance in early math, reading, and writing skills after accounting for general development, age, and socioeconomic status. Finally, the contribution of EF to early reading and writing skills remained stable between 3 and 5 years old. In contrast, EF was a stronger predictor of early math skills among 3-year-olds when compared to 5- year-olds.
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37

Malmqvist, Philip. "Monitoring of crack growth and crack mouth opening displacement in compact tension specimens at high temperatures : Development and implementation of the Direct Current Potential Drop (DCPD) method." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-44493.

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The mechanical engineering department at the University of Idaho is conducting a project with the purpose of developing a complete system for investigating creep-, creep-fatigue- and fatigue properties of metallic materials at elevated temperatures up to 650 ˚C with Compact Tension (CT) specimens. Considerable efforts have been made to study and understand these phenomena, although numerous problems still exist. It is important to explore more extensively the complicated phenomena of creep, fatigue and of creep-fatigue interactions. The Direct Current Potential Drop (DCPD) method is a common method used to investigate, for example, the initiation of cracks, crack growth rates and to monitor crack growth. The technique utilizes the fact that the electrical resistance of a CT specimen changes with crack growth. By applying a constant current over the specimen and measuring the resulting voltage over the crack, the crack length can be related to the voltage, and the difference in crack length with difference in voltage. Standards from the American Society for Testing of Materials (ASTM) were used as guidance when designing the DCPD system and CT specimen. The development and implementation processes were divided into an analytical and an experimental stage. The final product consisted of a high temperature extensometer, to measure crack mouth opening displacement (CMOD), and a DCPD system, to measure crack growth, controlled by separate control units. The DCPD system consisted of a DC supply and a nano voltmeter along with Constantan wire and NiCr60 wire respectively, that were mechanically fastened. The DCPD system delivered overall satisfying results and was able to generate sufficient data to produce a crack growth curve, da/dN vs. ΔK. Although, by taking advantage of resistance welding equipment to attach the DCPD wires, along with implementing one shared control unit for the DCPD system and the extensometer, more accurate and accessible measurements and correlations could be extracted.
Mechanical engineering avdelningen på University of Idaho genomför just nu ett utvecklingsprojekt med syftet att utveckla ett komplett system för undersökning av krypnings, krypnings-utmattnings- samt utmattnings- egenskaper av metalliska material vid höga temperaturer upp till 650 ˚C med hjälp av kompakta spänningsprovstavar (CT specimens). Betydande ansträngningar har gjorts för att undersöka och förstå dessa fenomen, men flera problem kvarstår. Det är viktigt att djupare undersöka kopplingen mellan krypnings- och utmattningsegenskaper. Direct Current Potential Drop (DCPD) metoden är en vanlig metod vilken används för att undersöka, exempelvis, sprickinitiering, spricktillväxthastigheter och spricktillväxt. Tekniken utnyttjar faktumet att den elektriska resistansen i en provstav ändras med spricktillväxt. Genom att föra en konstant ström genom provstaven och sedan mäta den resulterande spänningen över sprickan, kan spricklängden relateras till uppmätt spänning. På samma sätt kan spricktillväxt relateras till spänningsförändringar. Standarder från American Society for Testing of Materials (ASTM) användes för att designa ett DCPD system samt en CT provstav. Utvecklings- och implementeringsprocessen var uppdelad i en analytisk och en experimentell del. Den slutgiltiga produkten bestod av en extensometer, för mätning av spricköppning vid höga temperaturer, och ett DCPD system, för mätning av spricktillväxt vid höga temperaturer, vilka kontrollerades av separata kontrollenheter. DCPD systemet bestod av en strömkälla och en nanovoltmeter tillsammans med Constantan kablar respektive NiCr60 kablar, vilka fastsättes mekaniskt. DCPD systemet levererade generellt sett tillfredställande resultat och hade kapacitet att generera tillräckligt precisa data för att producera en spricktillväxtkurva, da/dN vs. ΔK. Däremot, genom att utnyttja en resistanssvets, för att fastsätta DCPD-kablarna, tillsammans med en gemensam kontrollenhet för extensometern och DCPD systemet, kan det tänkas att bättre och mer tillgängliga resultat kunde åstadkommas.
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38

Sarwar, Golam Babil Electrical Engineering &amp Telecommunications Faculty of Engineering UNSW. "Congestion control in DCCP for real-time applications over satellites and long delay wireless links." Awarded by:University of New South Wales. Electrical Engineering & Telecommunications, 2008. http://handle.unsw.edu.au/1959.4/43511.

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Today's de facto standard transport protocol for real time applications is UDP, which does not have congestion control. As TC;P is a reliable protocol it is not suited for real time applications. One of the basic objectives of formulating the Datagaram Congestion Control protocol (DCCP) was to help fight the ever existing problem of network overload for real-time applications by performing intelligent congestion control at the transport protocol level, which would be fair to co-existing TCP data streams. This problem becomes more serious and relevant ,when it comes to satellite links, where we have limited bandwidth, long delay and comparatively larger amount of transmission errors. This thesis focuses on three main things as a part of the research: first, it identifies the characteristics of DCCP over live satellite and 1011g range wireless links and evaluates their performance [l]. Secondly, it proposes modifications to DCCP's existing congestion control mechanisms so that it can perform better over satellite links [2]. And finally, the thesis extends its scope to VoIP applications and proposes further modifications to improve voice quality using DCCP over satellite links [3]. All the proposals presented in this thesis were first evaluated by simulation and then by performing experiments with a DCCP network stack of a real operating system and on a live satellite link.
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39

Santer, Roger D. "The role of the DCMD neuron in triggering emergency avoidance reactions in locusts and robots." Thesis, University of Newcastle Upon Tyne, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289095.

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40

Jero, Samuel C. "Performance Analysis of the Datagram Congestion Control Protocol DCCP for Real-Time Streaming Media Applications." Ohio University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1374854584.

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41

Petrie, Ryan John. "Cellular organization of the netrin receptor DCC and its associated signaling pathways." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=18667.

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The netrin-1 receptor Deleted in Colorectal Cancer (DCC) acts as a tyrosine kinase-associated receptor to mediate the attractive response of the growth cone towards the source of netrin-1. Fyn phosphorylates DCC on tyrosine 1418 to trigger neurite formation. DCC function requires lipid rafts, but it is not known how lipid rafts regulate DCC signaling. The activity of the Rho family GTPases Rac1 and Cdc42 are required to mediate DCC-dependent neurite formation. Determining how lipid rafts regulate DCC signaling and where Rac1 and Cdc42 activity is in a cell relative to DCC would aid in understanding the complex mechanism by which DCC connects netrin-1 binding to polarized cytoskeletal remodeling and axon growth to guide the growth cone towards the netrin-1 source. In the first part of this thesis, we have demonstrated that while netrin-1 binds to DCC in lipid rafts at the cell surface, DCC targeting to lipid rafts is insensitive to netrin-1 addition. DCC is phosphorylated both in rafts and non-lipid rafts and its association with Fyn and activation of FAK are all detected outside of lipid rafts. Thus, we show that while netrin-1 binds to DCC in lipid rafts, subsequent signals are propagated outside of this compartment independently of DCC translocation out of lipid rafts. In the second part, we developed a methodology and analysis regimen to image active Rac1 and Cdc42 by using sensitized emission fluorescence resonance energy transfer (FRET) in living cells and compared the utility of using intermolecular versus intramolecular FRET-based biosensors in visualizing Rho GTPase activity. In the last part we combined the FRET-biosensors with DCC in optimal imaging environment of Hela cells and determined that DCC localized to an F-actin enriched compartment on the cell surface, along with Rac1 and Cdc42, that did not correspond to early, late, or recycling endosomes. ICY-Cdc42 revealed that DCC colocalized with active Cdc42 and induced a gradient of Cdc42 activity, wh
Le récepteur transmembranaire Deleted in Colorectal Cancer (DCC) agit comme un récepteur à activité tyrosine kinase pour arbitrer l'attraction du cône de croissance vers une source de protéines chémotropiques, les nétrines. Fyn phosphoryle DCC sur le résidu tyrosine en position 1418 et cette action est nécessaire pour déclencher la formation de neurites. Les domaines membranaires appelés « lipid rafts » sont requis pour la fonction de DCC mais la façon dont ces « rafts » régulent la signalisation de DCC est jusqu'à ce jour inconnue. L'activité des GTPases Rho, en particulier celles de Rac1 et Cdc42, est cruciale pour la croissance de neurites induite par DCC. Démontrer la manière dont les rafts régulent la signalisation de DCC ainsi que positionner les activités de Rac1 et Cdc42 dans la cellule par rapport à DCC pourrait aider à comprendre le mécanisme complexe par lequel la nétrine-1 agit via DCC afin de provoquer la réorganisation du cytoskelette et la croissance axonale qui permet de guider le cône de croissance vers une source de nétrine-1. Dans la première partie de cette thèse, nous avons démontré que la nétrine-1 se lie à DCC à la surface cellulaire dans les rafts mais que la relocalisation de DCC dans ces domaines membranaires était insensible à l'ajout additionnel de nétrine-1. La phosphorylation de DCC survient aussi bien à l'intérieur ou à l'extérieur des rafts mais son association avec Fyn et l'activation de Fak sont des événements qui ont été seulement observés à l'extérieur des rafts. Par conséquent, nous montrons que lorsque la nétrine-1 se lie à DCC dans les rafts, des signaux subséquents se propagent à l'extérieur de ces domaines, indépendamment de la translocation de DCC à l'extérieur de ces derniers. Dans la deuxième partie, nous avons développé une méthodologie et une façon analytique servant à imager les activités de Rac1 et Cdc42 dans les cellules vivantes en utilisant la te
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42

Froggatt, Nicola Jane. "Alterations to the tumour suppressor genes p53 and dcc in colorectal neplasia." Thesis, University of York, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385322.

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43

Chen, Mu En, and 陳沐恩. "DCCP Based SVC Dynamic Streaming." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/54119037866692741628.

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碩士
國立中正大學
通訊工程研究所
99
Service of multimedia streaming is one of popular technology, which has been one of our daily life. It is a connectionless, unreliable, and best effort by using UDP transport layer protocol in Traditional multimedia. Generally speaking, UDP is more suitable than TCP. When network is congested, UDP takes a lot of bandwidth,which makes other service poor. Because UDP doesn’t know the condition of receivers, it can’t adjust its transmission rate. If the transmission rate is overloading, the event of packet loss may occur and reciever decode failed for video stream. Then the receivers’s video would be discontinuous, which is not welcome for user. It is hoped that DCCP(Datagram Congestion Control Protocol) replace UDP become transport layer protocol of multimedia service. DCCP, there is no retransmission property and congestion control. Therefore, it can mitigate congestion for network that DCCP adjust transmission rate with feedback when network is congested. In addition, the vedio would not appear the delay with DCCP because there is no retransmission mechanism in DCCP that is different with TCP. This paper use SVC(scalable video coding) to be our video format,which is a hierarchical structure and adapt different quality from one video .We use DCCP to be our transport layer protocol, and implement our Quality decision mechanism by feedback from receiver and characteristic of SVC. It is hoped that our mechanism can adjust level of SVC bitstream with variable condition of network to ensure basic quality of view when network is congested.
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44

Huang, Wei-Chih, and 黃薇之. "Reevaluate the DCC-GARCH and DCC-CARR model hedging performance." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/08907709827319368644.

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碩士
淡江大學
財務金融學系碩士在職專班
98
This article takes stock index and index future in United States, Germany and Japan as the research object . The sample period of S&P 500、DAX and Nikkei 225 index covers from 1/1/1991 to 31/12/2009, and the sample period of Dow Jones index covers from 1/1/1998 to 12/31/2009. The purpose of this study is to compare the out of sample performances among OLS、CCC-GARCH、DCC-GARCH、DCC-CARR models by using Variance、Utility function、Semi-variance、LPM and CVaR measurements. The empirical result shows: 1. OLS hedging model has the best out of sample performance. 2. In the dynamic model, if it only compares DCC-GARCH and DCC-CARR as the volatility forecasting estimator, DCC-CARR model has more accurate result. 3. If it takes transaction costs into the consideration, Utility function shows OLS and DCC-CARR models both have better hedging performances. Consideration the transaction cost, DCC-CARR model is also better than DCC-GARCH model.
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45

Chi, Hsin-Wei, and 紀信維. "Implementation of High Efficiency DCDC Converter." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/17075473241544416654.

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碩士
元智大學
電機工程學系
92
ABSTRACT The aim of this research is to develop a high efficiency DCDC converter. In the process of designing a DCDC converter,the output efficiency will be enhanced if a suitable circuit structure can be chosen first. In this thesis,the basic operation principle of Half Bridge Centro Tap and Current Double structure is discussed. Next, the consideration of component and circuit design is explained. Finally, a practical Half Bridge Current Double Converter based on the theory of DCDC converter is implemented to prove its accessibility. The study is conducted with four different structures.
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46

AbuHannoud, Ali. "A Framework for Better Understanding and Enhancing Direct Contact Membrane Distillation (DCMD) in Terms of Module Design, Cost Analysis and Energy Required." Thesis, 2011. http://hdl.handle.net/10754/209399.

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Water is becoming scarcer and several authors have highlighted the upcoming problem of higher water salinity and the difficulty of treating and discharging water. Moreover, current discoveries of problems with chemicals that have been used for pretreating or post-treating water alerted scientists to research better solutions to treat water. Membrane distillation (MD) is a promising technology that might replace current processes as it has lower pretreatment requirements combined with a tremendous ability to treat a wide range of feed sources while producing very high product quality. If it enters the market, it will have a big influence on all products, from food industry to spaceflight. However, there are several problems which make MD a hot topic for research. One of them is the question about the real cost of MD in terms of heating feed and cooling distillate over time with respect to product quantity and quality. In this work, extensive heating and cooling analyses are covered to answer this question in order to enhance the MD process. Results show energy cost to produce water and the main source of energy loss for direct contact membrane distillation (DCMD), and several suggestions are made in order to better understand and hence enhance the process.
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47

Chang-Chien, Chen-Yuan, and 張簡鎮遠. "Estimation and Comparison of five metal commodities futures with DCC-GARCH and DCC-CARR." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/07730881850407129290.

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碩士
國立高雄第一科技大學
財務管理研究所
100
This paper examines various hedging models, including OLS, NAIVE, DCC-GARCH and DCC-CARR to survey hedge performance in connection with metal commodities futures: gold, silver, platinum, copper and palladium by using proportional reduction in variance of portfolio and certainty equivalent. The result shows that the modeling technique of the DCC-CARR offers better risk reduction than other hedging models. It can boost hedge performance definitely by using dynamic changes of spot and futures price, also estimating conditional range to arrange hedge strategy. After hedging, most futures contracts can improve hedging effectiveness except for gold that can’t superior to the other model by using DCC-CARR. On the other hand, the study uses certainty equivalent method to Robustness test. The result shows that we can reach the maximum expect utility based on DCC-CARR model aside from gold and palladium.
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Chen, Nash, and 陳昱宏. "Optimal Hedge Ratio of Commodity Futures Using Bivariate DCC-CARR and DCC-GARCH Models." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/83027752092707981578.

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碩士
國立中央大學
財務金融研究所
93
When traders participate in both cash and futures markets they must choose a hedging strategy that reflects their individual goals and attitudes towards risk. At the same time, optimal portfolio management depends not only on the fundamental and technological analysis in maximizing returns, but it also encompasses diversification techniques in (un)systematic risk. Nevertheless, systematic risk can be effectively eliminated by futures contracts. In this thesis, we focus on diversification to minimize the portfolio variance and will consider the minimum-variance hedge strategy because the benefits of sophisticated estimation techniques of the hedge ratio are small (Lence, 1995b). At first, we take the commodity prices, and then compute the Optimal Hedge Ratios (OHRs) between spot and futures using different methods. Here, the hedge ratios are used to hedge the spot price risk in simulations of investment. In analysis, we use the Dynamic Conditional Correlation - Conditional Autoregressive Range (DCC-CARR) model proposed by Chou et. al. (2005) to compute the OHRs. Other alternative methods used for comparison include the ordinary least squares (OLS) estimator which provides an estimate for the minimum-variance hedge ratio, Constant Conditional Correlation –Generalized Autoregressive Conditional Heteroskedasticity and CARR (CCC-GARCH and CCC-CARR) models, and DCC-GARCH model. Different methods used to compute hedge ratios are compared with each other in their performance of variance-reduction. While the spot price risk is hedged by their corresponding futures, within-sample hedge, the results show that the DCC-CARR model performs better than the other hedge models for the selected commodities with the exception of gold. For an out-sample hedge in one-period it supports that the DCC-CARR model is the best model for any commodity. But, in other period, the results are mixed because of the trading noises. In conclusion, we suggest that the DCC-CARR model is the better model for investors to find the minimum-variance of a portfolio.
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49

Oliveira, Joana Sofia Almeida Donas de. "Estudo e otimização do processo RIM para DCPD." Dissertação, 2014. https://repositorio-aberto.up.pt/handle/10216/88379.

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50

Cheng, Ming-Tsung, and 鄭明宗. "DCCP Partial Reliability Extension with Sequence Number Compensation." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/49208452275372563460.

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碩士
國立臺灣科技大學
資訊管理系
96
Datagram Congestion Control Protocol (DCCP), possessing congestion control and unreliable transmission, specially suits real-time multimedia applications. Nevertheless, losses of key packets will cause a substantial decline on quality of services (QoS) in some applications. This paper proposes a DCCP partial reliability extension (PR-DCCP) that can retransmit lost packets as needed. Since DCCP uses an incremental sequence number, the retransmitted packets cannot utilize their original sequence number. To solve this problem, PR-DCCP adopts sequence number compensation, which appends an offset to the retransmitted packet; thus the receiver can use the sequence number of this retransmitted packet and the attached offset so as to re-obtain the original sequence number. The simulation uses two performance metrics: Decodable Frame Ratio (DFR) representing QoS, and Useless Data Received Ratio (UDRR) representing the bandwidth waste. These are used to evaluate different transport protocols, namely, PR-DCCP, DCCP, SCTP, TCP, and UDP. Simulation results show that PR-DCCP has the better DFR and UDRR than other transport protocols in almost all cases. For various movies, a DFR of PR-DCCP is 1.2% - 12.4% higher than that of DCCP; while UDRR is lower by 73.2% - 85.1%. Furthermore, two reliability policies to determine which packets require reliability are investigated. Finally, the comparisons between PR-DCCP and PR-SCTP are examined.
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