Dissertations / Theses on the topic '2:1 model'
To see the other types of publications on this topic, follow the link: 2:1 model.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic '2:1 model.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Ru, Hua. "A 2 1/2 dimensional thermohaline circulation model with boundary mixing." Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/58265.
Full textAbstract:
Thesis (S.M.)--Joint Program in Physical Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences and the Woods Hole Oceanographic Institution), 2000.Includes bibliographical references (leaves 78-82).
A simple quasi-two dimensional dynamical model of Thermohaline circulation (THC) is developed, assuming that the mixing only occurs near western and eastern boundary layers. When the surface density is prescribed, the climatically important quantities, such as the strength of overturning and meridional heat transport, are related to the zonal integral over the vigorously mixing regions and scaled as (KvΔx)2/3. The numerical results suggest that the density difference between eastern and western boundaries play an important role in the meridional overturning. The eastern boundary is characterized by the upwelling on top of downwelling. The western boundary layer is featured by the universal upwelling. The inefficiency of diffusion heat transport accounts for the narrowness of sinking region and shallowness of overturning cell in one-hemisphere. The experiments with other surface boundary conditions are also explored. The circulation patterns obtained are similar under various surface temperature distributions, suggesting these are very robust features of THC. The role of boundary mixing is further explored in global ocean. The 2 1/2 dynamical model is extended to two-hemisphere ocean. Additional dynamics such as Rayleigh friction and abyssal water properties are taken into account. A set of complicated governing equations are derived and numerically solved to obtain steady state solution. The basic circulation features are revealed in our dynamical model. An equtorially asymmetric meridional circulation is observed due to small perturbation at the surface temperature in the high latitude. The density differences between eastern and western boundaries are distinct in both hemispheres. This is achieved during the spin-up process. Although the dynamical model results agree well with OGCM results in one-hemisphere, several important dynamics are lacking and exposed in two-hemisphere experiments. We need to consider horizontal advection terms which will effectively advect positive density anomalies across the equator and form the deep water for the entire system.
by Hua Ru.
S.M.
2
Koktava, Rachel-Louise Kvertus. "Aspects of the gauged, twisted, SL(2|1)/SL(2|1) Wess-Zumino-Novikov-Witten model." Thesis, Durham University, 1996. http://etheses.dur.ac.uk/5291/.
Full textAbstract:
In this thesis we examine some of the interesting aspects of the Wess-Zumino- Novikov-Witten model when this model has been gauged and its energy tensor twisted by the addition of the derivative of one of its Cartan subalgebra valued currents. Specifically we consider the group valued model with the group taken as 5^(211) which is the Lie super group used to describe N = 2 supersymmetry. This model is advocated as being a good and natural description of the N = 2 superstring (also known as the charged spinning string, or N = 2 fermionic string) when it tensors an additional topological system of ghosts. The evidence for this assertion is presented by gauging and twisting the model and then extracting the N = 2 super Liouville action by the method of Hamiltonian reduction. The connection between the 5L (2|1)/5L (2|1) Wess-Zumino-Novikov-Witten model and field theory is made through its current algebra. As is true of many super groups there exists more than one interpretation of the Dynkin diagram for the algebra of 5L(2|1) and this results in more that one set of currents for this model. The classical and quantum currents in free field form are found in both cases, as is the highly non-linear transformation by which the two sets of currents are related. An analysis of a section of the cohomology of physical states of the model is undertaken. It is shown that the additional topological ghost system that tensors the gauged, twisted SL (2\l) model when it describes the N = 2 string only contributes a vacuum state to the overall cohomology, so reducing the analysis. As the 5L(2|1)/5L(2|1) Wess-Zumino-Novikov-Witten model is a topological field theory its spectrum of physical states lie in the cohomology class defined with respect to the BRST charge. The spectrum formed from the free field currents composes the so called Wakimoto module and this is calculated via the BRST formalism.
3
Davids, Stefan. "A state sum model for (2+1) Lorentzian quantum gravity." Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391393.
Full text
4
Nie, Shuquan. "Phenomenology of the SU(2)(L) x SU(2)(I) x U(1)(Y) x U(1)(Y') model." W&M ScholarWorks, 2001. https://scholarworks.wm.edu/etd/1539623377.
Full textAbstract:
We consider the effective low-energy SU(2) L x SU(2)I x U(1)Y x U(1)Y' model, which is based on the E6 grand unification theory. SU(2)I is a subgroup of SU(3) R and commutes with the electric charge operator.;Higgs bosons in the Standard Model and two-Higgs doublet models are reviewed and studied first. The flavor-changing neutral currents and their effects on the anomalous magnetic moment of the muon are discussed. Bounds on masses of Higgs bosons are obtained by requiring that the vacuum is stable and perturbation theory is valid up to a large scale. We introduce Higgs multiplets including two neutral doublets to break down SU(2)L x SU(2)I x U(1)Y x U(1) Y' to U(1) em. An upper bound of about 150 GeV to the lightest neutral Higgs scalar mass is found.;The gauge bosons corresponding to SU(2) I are charge-neutral. Production and effects of W I bosons are reviewed first. Mixings among neutral gauge bosons appear naturally. Electroweak precision experiments, including Z-pole experiments, mW measurements and low-energy neutral current experiments are used to put indirect constraints on masses of the extra neutral gauge bosons and the mixings between them and the ordinary Z boson. We also consider the possible constraint from a proposed measurement at Jefferson Lab of the proton's weak charge. It is found that the mixing angles are very small, namely ;theta; ≤ 0.005. The lower bound for the mass of the lightest extra neutral gauge boson is found to be about 560--800 GeV, which is comparable with the current direct search limit. Low-energy neutral current experiments give the strongest bounds on the lightest extra neutral gauge boson.;Fermions reside in the 27 fundamental representation of E6. We study the pair production of heavy charged exotic leptons at e+e- colliders in this model. In addition to the standard gamma and Z boson contributions, a t-channel contribution due to WI-boson exchange, which is unsuppressed by mixing angles, is quite important. We calculate the cross section, the left-right and forward-backward asymmetries, and discuss how to differentiate different models.
5
Lozano, Dairon Andrés Jiménez. "Modelo de Heisenberg Antiferromagnético de spin-1/2 na rede triangular com interações competitivas." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-21092016-212043/.
Full textAbstract:
Nesta dissertação estudamos sistemas de spins em redes de baixa dimensionalidade e em temperatura nula, analisando suas transições de fases quânticas. Mais precisamente, estu- damos as propriedades do estado fundamental e as possíveis transições de fase do modelo de Heisenberg quântico antiferromagnético de spin-1/2, com interações entre os primeiros e segundos vizinhos, em diversas redes, e em particular na rede triangular, que é o foco de nosso estudo. Para a obtenção do estado fundamental aproximado, usamos um método variacional em que a rede é particionada num conjunto de plaquetas de sítios. O estado fundamental é escrito como um produto tensorial dos estados das plaquetas. Para a rede triangular, escolhemos um triângulo como uma plaqueta. Quatro fases foram encontra- das: a fase antiferromagnética de Néel, a colinear, a fase de Néel modificada e aquela que denominamos de ligação covalente ressonante. Obtivemos as energias e as magnetizações de subrede em função da razão entre as interações de primeiros e segundos vizinhos. En- tre as fases de Néel e a colinear, podemos observar a fase de ligação covalente ressonante caracterizada como um singleto quanto ao spin de cada plaqueta.In this thesis we study spin systems in low-dimensional lattices at zero temperature, analyzing their quantum phase transitions. More precisely, we study the properties of the ground state and the possible phase transitions in the antiferromagnetic spin-1/2 quan- tum Heisenberg model with interaction between the first and second neighbors, in several lattices, and in particular in the triangular lattice, which is the focus of our study. To obtain the approximate ground state, we use a variational method in which the lattice is partitioned into a set of plates of sites. The ground state is written as a tensor product of the states of plates. For the triangular lattice, we choose a triangle as a plate. Four phases were found: the antiferromagnetic Néel phase, the collinear, the modified Néel phase and that we call resonating valence bond. We obtained the energy and the magnetization as a function of the ratio of the interactions between the first and second neighbor sites. Between the Néel and collinear phases, we can observe the spin resonating valence bond phase, characterized as a singlet with respect to the spin of each plate.
6
CONTRERAS, ROXANA JIMENEZ. "TYPE-2 HIERARCHICAL NEURO-FUZZY BSP MODEL." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2007. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=10862@1.
Full textAbstract:
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOREste trabalho tem por objetivo criar um novo sistema de inferência fuzzy intervalar do tipo 2 para tratamento de incertezas com aprendizado automático e que proporcione um intervalo de confiança para as suas saídas defuzzificadas através do cálculo dos conjuntos tipo-reduzidos correspondentes. Para viabilizar este objetivo, este novo modelo combina os paradigmas de modelagem dos sistemas de inferência fuzzy do tipo 2 e redes neurais com técnicas de particionamento recursivo BSP. Este modelo possui principalmente a capacidade de modelar e manipular a maioria dos tipos de incertezas existentes em situações reais, minimizando os efeitos destas para produzir um melhor desempenho. Além disso, tem a capacidade autônoma de criar e expandir automaticamente a sua própria estrutura, de reduzir a limitação quanto ao número de entradas e de extrair regras de conhecimento a partir de um conjunto de dados. Este novo modelo fornece um intervalo de confiança, que se constitui em uma informação importante para aplicações reais. Neste contexto, este modelo supera as limitações dos sistemas de inferência fuzzy do tipo 2 - complexidade computacional, reduzido número de entradas permissíveis e forma limitada, ou inexistente, de criarem a sua própria estrutura e regras - e dos sistemas de inferência fuzzy do tipo 1 - adaptação incompleta a incertezas e não fornecimento de um intervalo de confiança para a saída. Os sistemas de inferência fuzzy do tipo1 também apresentam limitações quanto ao reduzido número de entradas permissíveis, mas o uso de particionamentos recursivos, já explorado com excelentes resultados [SOUZ99], reduz significativamente estas limitações. O trabalho constitui-se fundamentalmente em quatro partes: um estudo sobre os diferentes sistemas de inferência fuzzy do tipo 2 existentes, análise dos sistemas neuro-fuzzy hierárquicos que usam conjuntos fuzzy do tipo 1, modelagem e implementação do novo modelo neuro-fuzzy hierárquico BSP do tipo 2 e estudo de casos. O novo modelo, denominado modelo neuro-fuzzy hierárquico BSP do tipo 2 (NFHB-T2), foi definido a partir do estudo das características desejáveis e das limitações dos sistemas de inferência fuzzy do tipo 2 e do tipo 1 e dos sistemas neuro-fuzzy hierárquicos que usam conjuntos fuzzy do tipo 1 existentes. Desta forma, o NFHB-T2 é modelado e implementado com os atributos de interpretabilidade e autonomia, a partir da concepção de sistemas de inferência fuzzy do tipo 2, de redes neurais e do particionamento recursivo BSP. O modelo desenvolvido é avaliado em diversas bases de dados benchmark e aplicações reais de previsão e aproximação de funções. São feitas comparações com outros modelos. Os resultados encontrados mostram que o modelo NFHB-T2 fornece, em previsão e aproximação de funções, resultados próximos e em vários casos superiores aos melhores resultados proporcionados pelos modelos utilizados para comparação. Em termos de tempo computacional, o seu desempenho também é muito bom. Em previsão e aproximação de funções, os intervalos de confiança obtidos para as saídas defuzzificadas mostram-se sempre coerentes e oferecem maior credibilidade na maioria dos casos quando comparados a intervalos de confiança obtidos por métodos tradicionais usando as saídas previstas pelos outros modelos e pelo próprio NFHB-T2 .
The objective of this thesis is to create a new type-2 fuzzy inference system for the treatment of uncertainties with automatic learning and that provides an interval of confidence for its defuzzified output through the calculation of corresponding type-reduced sets. In order to attain this objective, this new model combines the paradigms of the modelling of the type-2 fuzzy inference systems and neural networks with techniques of recursive BSP partitioning. This model mainly has the capacity to model and to manipulate most of the types of existing uncertainties in real situations, diminishing the effects of these to produce a better performance. In addition, it has the independent capacity to create and to expand its own structure automatically, to reduce the limitation referred to the number of inputs and to extract rules of knowledge from a data set. This new model provides a confidence interval, that constitutes an important information for real applications. In this context, this model surpasses the limitations of the type-2 fuzzy inference systems - complexity computational, small number of inputs allowed and limited form, or nonexistent, to create its own structure and rules - and of the type-1 fuzzy inference systems - incomplete adaptation to uncertainties and not to give an interval of confidence for the output. The type-1 fuzzy inference systems also present limitations with regard to the small number of inputs allowed, but the use of recursive partitioning, already explored with excellent results [SOUZ99], reduce significantly these limitations. This work constitutes fundamentally of four parts: a study on the different existing type-2 fuzzy inference systems, analysis of the hierarchical neuro- fuzzy systems that use type-1 fuzzy sets, modelling and implementation of the new type-2 hierarchical neuro-fuzzy BSP model and study of cases. The new model, denominated type-2 hierarchical neuro-fuzzy BSP model (T2-HNFB) was defined from the study of the desirable characteristics and the limitations of the type-2 and type-1 fuzzy inference systems and the existing hierarchical neuro-fuzzy systems that use type- 1 fuzzy sets. Of this form, the T2-HNFB model is modelling and implemented with the attributes of interpretability and autonomy, from the conception of type-2 fuzzy inference systems, neural networks and recursive BSP partitioning. The developed model is evaluated in different benchmark databases and real applications of forecast and approximation of functions. Comparisons with other models are done. The results obtained show that T2-HNFB model provides, in forecast and approximation of functions, next results and in several cases superior to the best results provided by the models used for comparison. In terms of computational time, its performance also is very good. In forecast and approximation of functions, the intervals of confidence obtained for the defuzzified outputs are always coherent and offer greater credibility in most of cases when compared with intervals of confidence obtained through traditional methods using the forecast outputs by the other models and the own T2-HNFB model.
7
Altunel, Fatih. "Model Updating Of A Helicopter Structure Using A Newly Developed Correlation Improvement Technique." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/2/12611300/index.pdf.
Full textAbstract:
Numerical model usage has substantially increased in many industries. It is the aerospace industry that numerical models play possibly the most important role for development of optimum design. However, numerical models need experimental verification. This experimental verification is used not only for validation, but also updating numerical model parameters. Verified and updated models are used to analyze a vast amount of cases that structure is anticipated to face in real life.
In this thesis, structural finite element model updating of a utility helicopter fuselage was performed as a case study. Initially, experimental modal analyses were performed using modal shakers. Modal analysis of test results was carried out using LMS Test.lab software. At the same time, finite element analysis of the helicopter fuselage was performed by MSC.Patran &Nastran software. v Initial updating was processed first for the whole helicopter fuselage then, tail of the helicopter was tried to be updated. Furthermore, a new method was proposed for the optimum node removal location for getting better Modal Assurance Criterion (MAC) matrix. This routine was tried on the helicopter case study and it showed better performance than the Coordinate Modal Assurance Criterion (coMAC) that is often used in such analyses.
8
Peacock, Christopher. "Modelling cointegrated 1(2) systems with an application to money and exchange rates." Thesis, University of Southampton, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250050.
Full text
9
Almeida, Sabrina Ribeiro de. "REPRODUÇÃO EXPERIMENTAL E CARACTERIZAÇÃO CLÍNICOPATOLÓGICA DA MAMILITE PELO HERPESVÍRUS BOVINO TIPO 2 (BoHV-2) EM OVINOS." Universidade Federal de Santa Maria, 2006. http://repositorio.ufsm.br/handle/1/10166.
Full textAbstract:
Conselho Nacional de Desenvolvimento Científico e TecnológicoThe bovine mammillits caused by bovine herpesvirus type 2 (BoHV-2) is an important disease of dairy cattle yet very little is known about its pathogenesis. This study aimed at reproducting and characterizing the clinical-pathological aspects of bovine herpesvirus mammillits in experimentally infected sheep. In the first experiment, ten lambs were inoculated in the nasal mucosa and the virological, clinical and serological aspects of acute infection were monitorated. Virus sheeding was detected in nasal secretions of 7 lambs between days 2 and 8 post inoculation (pi) and lasted from one to three days. A serous nasal discharge, changing to mucous and mucopurulent, was observed in all animals between days 2 and 5 pi. Seven lambs developed vesicles, pustules and erosions in the nasal mucosa between days 4 and 8 pi. All inoculated animals seroconverted to BoHV-2. Dexamethasone administration at day 40 pi was not followed by virus shedding, clinical recrudescence or seroconversion. In the second experiment, eight milking ewes were inoculated in the skin of the teats and udder, and monitorated thereafter regarding to viral replication, clinical signs and histological changes. Infectious virus was isolated from lesion swabs of one ewe on days 7 and 8 pi. Five animals developed lesions in inoculation sites between days 4 and 6 pi. The clinical-pathological aspects of the lesions were similar to those of natural infections and were characterizated by erythema, edema, papules, vesicles, exsudation and scabs. By histological examination, the lesions displayed cellular edema and linfoplasmocitic multifocal infiltrate surrounding blood vessels in the dermis. Moreover, eosinophilic intranuclear inclusion bodies were observed in inflamatory cells and syncitia. Virus particles resembling herpesvirus were observed by eletronic transmission microscopy. These results indicate that sheep are susceptible to BoHV-2 infection, and can develop clinical signs similar to those observed in cattle in natural outbreaks of herpes mammillitis. Thus, this animal species may be used as a model to study pathogenesis, vaccine development and antiviral drugs.
A mamilite causada pelo herpesvírus bovino tipo 2 (BoHV-2) é uma importante enfermidade de gado leiteiro, porém pouco se sabe sobre a sua patogenia. O presente trabalho teve como objetivos reproduzir e caracterizar em ovinos as manifestações clínico-patológicas associadas com a infecção natural de bovinos pelo BoHV-2. Em um primeiro experimento, dez cordeiros foram inoculados na mucosa nasal e a infecção aguda foi monitorada nos aspectos clínicos, virológicos e sorológicos. Excreção viral em secreções nasais foi detectada em 7/10 animais entre os dias 2 e 8 pós-inoculação (pi), com duração que variou entre um e três dias. Todos animais apresentaram secreção nasal serosa, passando a mucosa e mucopurulenta, entre os dias 2 e 5 pi, e sete deles apresentaram também hiperemia e o desenvolvimento de vesículas, pústulas e erosões na mucosa nasal entre os dias 4 e 8 pi. Todos os animais soroconverteram ao BoHV-2. A administração de dexametasona aos 40 dias pi não foi seguida de excreção viral, soroconversão ou recrudescência clínica. Em um segundo experimento, oito ovelhas lactantes foram inoculadas na pele das tetas e do úbere, seguida da caracterização virológica, clínica e histopatológica da infecção aguda. O vírus foi isolado a partir de suabes coletados das lesões de uma ovelha nos dias 7 e 8 pi. Cinco (5/8) animais desenvolveram lesões nos locais de inoculação entre os dias 4 e 6 pi. As lesões apresentaram características clínicopatológicas semelhantes às observadas em infecções naturais, e se caracterizaram por hiperemia, edema, pápula, vesículas, exsudação e formação de crostas. Histologicamente, as lesões se caracterizaram por edema intracelular, presença de um infiltrado linfoplasmocitário multifocal e predominantemente perivascular na derme, além de corpúsculos de inclusão eosinofílicos intranucleares em células inflamatórias e células sinciciais. Partículas víricas com morfologia típica de herpesvírus foram observadas sob microscopia eletrônica de transmissão. Esses resultados indicam que ovinos são susceptíveis à infecção pelo BoHV-2 e desenvolvem lesões características de mamilite herpética quando inoculados experimentalmente, podendo ser utilizados para estudos de patogenia, desenvolvimento de vacinas e pesquisas de drogas antivirais.
10
Jaroš, Petr. "Konstrukce 1/4 modelu vozidla pro testy tlumičů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2021. http://www.nusl.cz/ntk/nusl-442802.
Full textAbstract:
This thesis deals by the design of 1/4 car model for testing vehicle dampers, which can be used to simulate the real suspension of a vehicle wheel (up to a maximum car weight of 1,970 kg) and the so-called linear wheel suspension. A linear mathematical 1/4 car model with 2 DOF (Degrees Of Freedom) and data from literature search are used to design and derive the basic parameters of the device. The thesis contains a description of the linear mathematical model and its outputs (acceleration of the sprung mass and forces acting on the sprung mass), description of designed device, descriptions of created simulations (static, modal and harmonic analysis in ANSYS Workbench 2020 R2) and conceptual design of the modifications this device for another possible use for testing of bicycles.
11
Yong, Mostyn R. "Characterisation of Polycaprolatone-Based Scaffold Plus Recombinant Human Morphogenetic Protein - 2 (RHBMP-2) in an Ovine Thoracic Spine Model." Thesis, Queensland University of Technology, 2013. https://eprints.qut.edu.au/64093/1/Mostyn_Yong_Thesis.pdf.
Full textAbstract:
This thesis represents a step forward in the development of a pre-clinical model investigating a suitable substitute for host bone for use in human spinal fusion.
By way of an animal model, it examines the biological performance of a novel bone graft substitute comprised of a combination of a custom-designed biodegradable material and biologics.
12
Adegoke, Adekunle M. "The one-dimensional spin-1/2 ANNNI model in non-commuting magnetic fields." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=980733596.
Full text
13
White, Rebecca Joy. "A priming / temperament model of system 1 and system 2 decision making processes." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1124291507.
Full textAbstract:
Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains x, 153 p.; also includes graphics (some col.). Includes bibliographical references (p. 118-127). Available online via OhioLINK's ETD Center
14
Yehia, Ali. "Wenckebach rhythms and [1:1<->2:1] bistability in single rabbit ventricular cells and in a ventricular ionic model." Thesis, McGill University, 1999. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=36738.
Full textAbstract:
Stimulating a rabbit ventricular cell with a train of current pulses at a long basic cycle length (BCL) and high pulse amplitude (PA) leads to a 1:1 rhythm, where each injected pulse generates an action potential. With a fixed BCL (BCL = 300 ms at 34--36°C and BCL = 1000 ms at 22--24°C), as PA is decreased, there is a transition from 1:1 rhythm to Wenckebach rhythms. These rhythms are characterized by a beat-to-beat increment in latency and action potential duration (APD) culminating in a skipped beat. Using voltage and action potential clamp, as well as a specific channel blocker, I show that the transient outward current (Ito) is implicated in the generation of these APD increments, and is responsible for the periodicity of these rhythms. When PA is raised, a direct transition from 1:1 to 2:1 rhythm can be observed by varying BCL. With the use of an ionic model, hysteresis between 1:1 and 2:1 rhythms is shown and compared to similar hysteresis observed previously in experiments with rabbit ventricular cells. When the BCL is within the hysteresis range, the addition of stimulus pulses flips 1:1 to 2:1 rhythm and vice versa, providing evidence for bistability. With the ionic model, the substraction of a single pulse also flipped 1:1 to 2:1 rhythm. Iteration of a finite-difference equation, derived using the steady-state APD restitution curve, predicts the direct {1:1 ↔ 2:1} transition, as well as bistability, in both the experimental and modeling work. Finally, I show in an ionic model that the transition from 1:1 to 2:1 rhythms: (1) is interrupted by Wenckebach rhythms at low PAs; (2) is direct without hysteresis at one specific higher PA value; (3) is direct with hystersis at still higher PAs. While iteration of the APD restitution curve predicted {1:1 ↔ 2:1} bistability at higher PA, iteration of the latency restitution curve predicted Wenckebach rhythms at lower PA, confirming the importance of latency for the existence of Wenckebach rhythms
15
Oguz, Hatice Dilek. "Pricing Us Corporate Bonds By Jarrow/turnbull (1995) Model." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/2/12611174/index.pdf.
Full textAbstract:
In this study Jarrow Turnbull (1995) Model, which is a reduced form approach for credit risk models, is employed to estimate the default intensity of US corporate bonds conditionally based on a fixed recovery rate. The estimations are performed with respect to the ratings of the bonds and the results were consistent with the ratings. US Treasury Bills are also used to since zero coupon default free prices, modeled by Svensson (1994) are necessary for pricing the default risky coupon bonds.
16
Santos, Marcelo Trindade dos. "Correções Quânticas 1/N ao Limite Clássico: Aplicação ao Modelo de Lipkin SU(2)." Universidade de São Paulo, 1997. http://www.teses.usp.br/teses/disponiveis/43/43131/tde-15052012-141043/.
Full textAbstract:
Neste trabalho mostramos de que maneira o princípio variacional dependente do tempo pode ser usado para se estudar correções quânticas ao limite clássico, particularmente, no contexto do modelo de Lipkin SU(2). Mostramos que tais correções podem ser colocadas na forma Hamiltoniana, acoplando-se a dinâmica clássica um conjunto de variáveis associadas às flutuações quânticas, nos levando à uma dinâmica efetiva com o número de graus de liberdade dobrado em relação ao sistema clássico. Como conseqüência o comportamento caótico emerge. Mostramos que este caos semiquântico é o mecanismo através do qual o tunelamento se manifesta no espaço de fase. Mostramos que tais correções melhoram sistematicamente o resultado c1ássico, propondo um critério para quantificar esta melhora.We show how the time dependent variational principle can be used to study quantum corrections to the classical limit, in particular of the SU(2) Lipkin Model. We show how much corrections can be cast in Hamiltonian form, coupling to the classical dynamics a set of variables associated to the quantum fluctuations. This leads to an effective dynamics which has the number of degrees of freedom doubled with respect to the classical system. As a consequence chaotic behavior emerges. We show that this semiquantal chaos is the mechanism through which tunneling is effected, and also, that these corrections systematically improve the classical results and propose some quantitative measure of this improvement.
17
Kaya, Orcun. "Static Hedging Strategies For Barrier Options And Their Robustness To Model Risk." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/2/12608763/index.pdf.
Full textAbstract:
With the rapid increase in the usage of barrier options on the OTC markets, pricing and especially hedging of these exotic instruments became an important field of research. This paper aims to explain, apply and compare current methods used for pricing and hedging barrier options with a simulation approach. An overview of most popular methods for pricing and hedging is presented in the first part, followed by application of these pricing methods and comparing the performances of different dynamic and static hedging techniques in Black-Scholes environment by simulation in the second part. In the third part different models such as ARCH type and Stochastic Volatility are used with different jump terms to relax the assumptions of the Black-Scholes and examine the effects of these incomplete models on both pricing and performance of different hedging techniques. In the fourth part diffusion models such as Constant Variance Elasticity, Heston Stochastic Volatility and Merton Jump Diffusion are used to complete the picture.
18
Gustavsson, Katarina. "Mathematical and Numerical Modeling of 1-D and 2-D Consolidation." Doctoral thesis, KTH, Numerical Analysis and Computer Science, NADA, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3497.
Full textAbstract:
A mathematical model for a consolidation process of a highlyconcentrated, flocculated suspension is developed.Thesuspension is treated as a mixture of a fluid and solidparticles by an Eulerian two-phase fluid model.W e characterizethe suspension by constitutive relations correlating thestresses, interaction forces, and inter-particle forces toconcentration and velocity gradients.This results in threeempirically determined material functions: a hystereticpermeability, a non-Newtonian viscosity and a non-reversibleparticle interaction pressure.P arameters in the models arefitted to experimental data.
A simulation program using finite difference methods both intime and space is applied to one and two dimensional testcases.Numer ical experiments are performed to study the effectof different viscosity and permeability models. The effect ofshear on consolidation rate is studied and it is significantwhen the permeability hysteresis model is employed.
19
Covington, David Allen. "The pattern of glory a model for apologetics from 2 Corinthians 4:1-6 /." Theological Research Exchange Network (TREN), 1997. http://www.tren.com.
Full text
20
Uner, Gorkem. "Development Of A Material Cutting Model For Haptic Rendering Applications." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/2/12609185/index.pdf.
Full textAbstract:
Haptic devices and haptic rendering is an important topic in the burgeoning field of
virtual reality applications. In this thesis, I describe the design and implementation of
a cutting force model integrating a haptic device, the PHANToM, with a high &ndashpowered computer. My goal was to build a six degree &ndash
of &ndash
freedom force model to allow user to interact with three &ndash
dimensional deformable objects. Methods for haptic rendering including graphical rendering, collision detection and force feedback are illustrated, implementation of haptic rendering system is introduced, and application is evaluated to explore the effectiveness of the system.
21
Atabay, Seda. "Social Market Economy: A Discursive Framework For European Social Model?" Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/2/12610222/index.pdf.
Full textAbstract:
The thesis mainly scrutinizes the evolution of European Social Dimension from the early period of the European integration to the Lisbon Summit of 2000 and the formation of the draft EU Constitution in 2003. While the focus is on the changing role of social policy at the European Union level during the period of welfare state transformation, the thesis tries to lay down the normative and discursive linkages constructed between the concepts of European Social Model and the Social Market
Economy. Subsequent to the inquiry made into the theoretical foundations of the Social Market Economy and its practice in Germany, the thesis discusses how diverse European actors employ the concept, which is ambiguous in nature, as a comprehensive framework within which a European political identity that may be constructed around European Social Model could be grounded.
22
Jezo, Tomas. "Z' and W' gauge bosons in SU(2)xSU(2)xU(1) models : Collider phenomenology at LO and NLO QCD." Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENY071/document.
Full textAbstract:
Les modèles SU(2)xSU(2)xU(1) représentent une étape intermédiaire motivée par l'unification des groupes de jauge du Modèle Standard (MS). Un groupe de jauge étendu, par rapport a celui du MS, implique l'existence de nouveaux bosons de jauge, neutres et charges. Ces bosons dénotés Z' et W' sont recherches activement au Large Hadron Collider (LHC). Sur la base d'une analyse globale récente des contraintes sur ces modèles, provenant des expériences a basse énergie et du LEP, nous effectuons une analyse numérique au Leading Order (LO) des différentes signatures au LHC. Nous montrons que les sections efficaces totales pour les leptons et les paires de quarks de troisième génération, expérimentalement facilement accessibles, fournissent individuellement qu'uneinformation partielles sur le modèle réalise dans la nature. En revanche, les corrélations de ces mêmes sections efficaces pourraient bien conduire a une identification unique. Par la suite, nous étudions la production électrofaible d'une paire de quarks top au Next-to-Leading Order dans les extensions du MS prédisant un boson Z' supplémentaire et en supposant des couplages génériqueset diagonaux dans la base des saveurs. Nous calculons les corrections virtuelles et réelles a l'ordre de O(alS*alW^2) et les implémentons dans le générateur d'événements Monte Carlo POWHEG BOX qui permet de réaliser de manière cohérente la fusion du calcul QCD NLO avec les parton showers. Nousconstatons que les corrections QCD NLO peuvent être très importantes, mais que les K-facteurs restent modestes dans la région de masse invariante centrée autour de la masse de la résonanceGeneral SU(2)x SU(2)x U(1) models represent a well-motivated intermediate step towards the unication of the Standard Model (SM) gauge groups. Extended gauge group sector, as compared to that of the SM, leads to additional neutral and charged gauge bosons. These so-called Z' and W' bosons are actively searched for at the Large Hadron Collider (LHC). Based on a recent global analysis of low-energy and LEP constraints of these models, we perform numerical scans of their various signals at the LHC at Leading Order accuracy. We show that total cross sections for lepton and third-generation quark pairs, while experimentally easily accessible, provide individually only partial information about the model realized in Nature. In contrast, correlations of these cross sections in the neutral and charged current channels may well lead to a unique identification. Subsequently we study the electroweak top-pair production at Next-to-leading Order (NLO) accuracy in the SM extensions with an additional Z' boson assuming general flavour-diagonal couplings. We calculate the virtual and real corrections at order O(alS*alW^2) and implement them in the POWHEG BOX framework which allows for consistent matching of NLO QCD calculations with parton showers. We find that the NLO corrections can be very important but the K-factors in the invariant mass region around the resonance mass are modest
23
LeSage, James P., and Manfred M. Fischer. "Conventional versus network dependence panel data gravity model specifications." WU Vienna University of Economics and Business, 2019. http://epub.wu.ac.at/6828/1/2019%2D2%2D11_v12_panel_gravity_model.pdf.
Full textAbstract:
Past focus in the panel gravity literature has been on multidimensional fixed effects specifications
in an effort to accommodate heterogeneity. After introducing conventional multidimensional fixed effects, we find evidence of cross-sectional dependence in
flows.
We propose a simultaneous dependence gravity model that allows for network dependence
in flows, along with computationally efficient Markov Chain Monte Carlo estimation methods
that produce a Monte Carlo integration estimate of log-marginal likelihood useful for model
comparison. Application of the model to a panel of trade
flows points to network spillover
effects, suggesting the presence of network dependence and biased estimates from conventional
trade flow specifications. The most important sources of network dependence were found to
be membership in trade organizations, historical colonial ties, common currency and spatial
proximity of countries.Series: Working Papers in Regional Science
24
Rumler, Fabio. "Computable general equilibrium modeling. Numerical simulations in a 2-country monetary general equilibrium model." Inst. für Volkswirtschaftstheorie und -politik, WU Vienna University of Economics and Business, 1999. http://epub.wu.ac.at/70/1/document.pdf.
Full textAbstract:
This paper presents the concept of numerical CGE modeling with the help of a 2-country general equilibrium model. In the framework of this simple dynamic monetary model the effects of a (unilateral) monetary and fiscal expansion are simulated. The exchange rate of the home vis-à-vis the foreign currency depreciates in response to both types of shocks. The monetary expansion leads to an increase in home relative to foreign private consumption and to a sharp increase in relative home output in the short run, while in the long run output increases in the foreign country and decreases in the home country. The unilateral fiscal expansion, on the other hand, results in a fall of private consumption in the home relative to the foreign country, and in an increase in relative home output in the short as well as in the long run. The world real interest rate falls quite substantially in response to both shocks. (author's abstract)Series: Department of Economics Working Paper Series
25
Howe, Peter A., and n/a. "Designing and evaluating an inservice model for mathematics education in the primary school." University of Canberra. Education, 1987. http://erl.canberra.edu.au./public/adt-AUC20060726.164520.
Full textAbstract:
The study presents a review of in-service models and a search
for an effective in-service model for mathematics education in
the primary school.
The study considers the need to improve the teaching of
mathematics in the primary school; the major reports that have
made recommendations for the improvement of primary mathematics
teaching and the opinions and findings of mathematics
educators. The study examines the state of the art of
in-service models and examines those models previously used.
The study notes the failings of the in-service models past and
present and examines elements within these models which have
proven to be beneficial albeit in part. Throughout the study
particular attention is given to recent studies concerned with
implementing and sustaining change.
The model designed for the in-service of the primary mathematics
teacher, MINC (Mathematics In-service Network Course) is based
on an examination of models past and present. Components and
provisions that have met with success in these models were
included in the design.
The in-service model developed and described in this study
includes four major components input from course leaders and
teachers, reflection, feedback and the opportunity for teachers
to work with others from the same school and neighbouring
schools (networking).
A major section of the study examines the responses of
participants to an evaluation questionnaire given at the
completion of the first in-service course, MINC 1 and the
second, MINC 2.
Data collected from the responses of participants to the
questionnaire were analysed to see if there were differences in
responses from teachers based on such factors as sex, the MINC
network, the level to which participants had studied
mathematics, the year level they taught and expressed confidence
in teaching mathematics.
In conclusion, the study reflects on the evaluation of the
in-service course and addresses considerations for future
in-service courses concerned with mathematics education for
primary teachers.
26
Snook, Max Ray. "An examination of the Petrine model for the development of knowledge from 2 Peter 1:5." Theological Research Exchange Network (TREN), 1995. http://www.tren.com.
Full text
27
Quirici, Wagner José. "Modelo conceitual para o desenvolvimento de arranjos produtivos locais." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/12/12139/tde-18062007-153505/.
Full textAbstract:
A globalização da economia, com a queda das barreiras comerciais e a abertura dos mercados nacionais, tem produzido forte impacto nas estruturas de produção locais gerando ameaças e oportunidades para as pequenas e médias empresas, exigindo destas uma estratégia para inserção na nova economia. O fenômeno da localização, com o surgimento de aglomerações de empresas de um mesmo setor de especialização, os chamados arranjos produtivos locais, tem propiciado às pequenas e médias empresas uma importante estratégia de sobrevivência e de inserção no mercado globalizado. Existem na literatura diversos estudos sobre arranjos produtivos locais. Parte significativa dos estudos empíricos sobre o tema focam, com base em análise quantitativa (grau de especialização regional, índice de concentração em setores industriais, numero de empregados no setor etc.), no potencial de uma aglomeração empresarial de um setor, em uma região específica, de se tornar um arranjo produtivo. Em contraste, existem poucos estudos que busquem compreender a natureza do fenômeno, identificando seus principais fatores direcionadores, as inter-relações entre eles, seus padrões e sua dinâmica de desenvolvimento e de como os agentes locais podem planejar e realizar sua gestão. Existe, portanto, a necessidade de se aprofundar estudos que eliminem essas deficiências e que permitam a construção de um modelo conceitual que contribua para o desenvolvimento e a consolidação dos arranjos produtivos locais. Este é o objetivo do presente trabalho, realizar uma pesquisa exploratória qualitativa que com base em revisão teórica e entrevistas com gestores de arranjos produtivos, aprofunde os conhecimentos do fenômeno dos arranjos produtivos buscando identificar os fatores determinantes para o seu surgimento e para sua dinâmica de desenvolvimento. A partir desses conhecimentos construir um modelo conceitual que permita sistematizar os processos de planejamento, aprendizado, implementação e de gestão, enfim, contribua para o desenvolvimento e a consolidação de arranjos produtivos locais emergentes.The globalization of the economy, the progressive elimination of barriers to trade and the opening of national markets, have produced a strong impact on the local production structures, carrying out threats and opportunities to small and medium companies demanding of them an strategy that insert them in the new economy. The emerge of conglomeration of companies of the same sector of specialization, so called local productive arrangements, has propitiate to the small and medium companies an important insertion strategy in the global market. Indeed, this kind of industrial/regional organization has become an important piece in the implementation of industrial, regional and technological policies to respond to increasingly open markets. There are in the literature many studies on local productive arrangements. Accordingly, a significant part of empirical studies on this subject has been focused on the potential of a sector, in a specific region, to become a local productive arrangement based on quantitative analysis (regional specialization, index of concentration in industrial sectors, number of employees in sector etc.). In contrast, there are few studies that try to understand the nature of the phenomena, its startup?s main drivers factors, the pattern of development of these arrangements and how the local stakeholders could plan and manager them. Taking this into account, it is necessary to develop conceptual models that are able to overcome this deficiency. A combination of quantitative and qualitative analysis is therefore appropriate to identify the most competitive industries and their internal interrelationships. Qualitative analysis such as interviews with local leaders for instance are required to understand interactions and relationships identified through quantitative tools. Beyond the actual findings obtained, analysis can also help identify the most suitable policy targets as well as benchmarks for the evaluation of subsequent arrangement?s plan and management of its performance. This is the aim of this paper, an exploratory research based on theory review, case studies and interviews with local stakeholders propose a conceptual model to plan and to manager the phenomena of local productive arrangements. The greatest benefit of the conceptual model is thus its capacity to give regional economic development policy and sometimes fragmented organizations and plan areas a unifying focus.
28
Saglam, Ferhat. "Identification Of Low Order Vehicle Handling Models From Multibody Vehicle Dynamics Models." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/2/12611505/index.pdf.
Full textAbstract:
Vehicle handling models are commonly used in the design and analysis of vehicle dynamics. Especially, with the advances in vehicle control systems need for accurate and simple vehicle handling models have increased. These models have parameters, some of which are known or easily obtainable, yet some of which are unknown or difficult to obtain. These parameters are obtained by system identification, which is the study of building model from experimental data.
In this thesis, identification of vehicle handling models is based on data obtained from the simulation of complex vehicle dynamics model from ADAMS representing the real vehicle and a general methodology has been developed. Identified vehicle handling models are the linear bicycle model and vehicle roll models with different tire models. Changes of sensitivity of the model outputs to model parameters with steering input frequency have been examined by sensitivity analysis to design the test input. To show that unknown parameters of the model can be identified uniquely, structural identifiability analysis has been performed. Minimizing the difference between the data obtained from the simulation of ADAMS vehicle model and the data obtained from the simulation of simple handling models by mathematical optimization methods, unknown parameters have been estimated and handling models have been identified. Estimation task has been performed using MATLAB Simulink Parameter Estimation Toolbox. By model validation it has been shown that identified handling models represent the vehicle system successfully.
29
Hasselfield, Matthew. "Localization of a particle due to dissipation in 1 and 2 dimensional lattices." Thesis, Vancouver : University of British Columbia, 2006. http://hdl.handle.net/2429/74.
Full textAbstract:
We study two aspects of the problem of a particle moving on a lattice while subject to dissipation, often called the "Schmid model." First, a correspondence between the Schmid model and boundary sine-Gordon field theory is explored, and a new method is applied to the calculation of the partition function for the theory. Second, a traditional condensed matter formulation of the problem in one spatial dimension is extended to the case of an arbitrary two-dimensional Bravais lattice.
A well-known mathematical analogy between one-dimensional dissipative quantum mechanics and string theory provides an equivalence between the Schmid model at the critical point and boundary sine-Gordon theory, which describes a free bosonic field subject to periodic interaction on the boundaries. Using the tools of conformal field theory, the partition function is calculated as a function of the temperature and the renormalized coupling constants of the boundary interaction. The method pursues an established technique of introducing an auxiliary free boson, fermionizing the system, and constructing the boundary state in fermion variables. However, a different way of obtaining the fermionic boundary conditions from the bosonic theory leads to an alternative renormalization for the coupling constants that occurs at a more natural level than in the established approach.
Recent renormalization group analyses of the extension of the Schmid model to a two-dimensional periodic potential have yielded interesting new structure in the phase diagram for the mobility. We extend a classic one-dimensional, finite temperature calculation to the case of an arbitrary two-dimensional Bravais lattice. The duality between weak-potential and tightbinding lattice limits is reproduced in the two-dimensional case, and a perturbation expansion in the potential strength used to verify the change in the critical dependence of the mobility on the strength of the dissipation. With a triangular lattice the possibility of third order contributions arises, and we obtain some preliminary expressions for their contributions to the mobility.
30
Reichl, Johannes, and Sylvia Frühwirth-Schnatter. "A Censored Random Coefficients Model for the Detection of Zero Willingness to Pay." Springer, 2011. http://epub.wu.ac.at/3707/1/WU_epub_(2).pdf.
Full textAbstract:
In this paper we address the problem of negative estimates of willingness to pay. We find that there exist a number of goods and services, especially in the fields of marketing and environmental valuation, for which only zero or positive WTP is meaningful. For the valuation of these goods an econometric model for the analysis of repeated dichotomous choice data is proposed. Our model restricts the domain of the estimates of WTP to strictly positive values, while also allowing for the detection of zero WTP. The model is tested on a simulated and a real data set.
31
Lambers, Rebeca. "Development of a model to risk manage construction defects in the residential sector." Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/134079/2/Rebeca_Lambers_Thesis%5B1%5D.pdf.
Full textAbstract:
This research unfolds the frequently occurring defects in the residential construction sector and examines those key defects in depth. In particular, the research extends existing knowledge about defects causation and management and assesses the practical barriers and nature of trade work in Queensland residential construction. Findings of this research suggest that key risk management strategies and causes for defects are specific to each construction trade and only a few risk-management strategies can be administered through all the residential trades. This study provides building professional stakeholders with a comprehensive mapping of defects causation and management synthetised in a risk–management model that can be used as a guide to prioritise the management of significant construction defects, so that efforts can be directed at strengthening key pitfall areas.
32
Flottat, Thibaut. "Bosons couplés à des spins 1/2 sur réseau." Thesis, Université Côte d'Azur (ComUE), 2016. http://www.theses.fr/2016AZUR4080/document.
Full textAbstract:
Les systèmes fortement corrélés, pouvant adopter des phases surprenantes de la matière, émergent dans le domaine des atomes ultra-froids ou dans celui de l’électrodynamique quantique en cavité (CQED). Ceux-ci sont au centre d’intenses travaux expérimentaux et théoriques. Dans cette thèse, nous présentons une étude de deux modèles de bosons avec deux ou zéro états internes. Ceux-ci peuvent se déplacer sur un réseau, et sont localement couplés avec des spins 1/2. Notre intérêt réside dans la détermination du diagramme de phase de l’état fondamental de ces systèmes ainsi que de l’étude des propriétés de phase et des transitions entre ces dernières. Nous avons utilisé deux outils : une approximation de champ moyen et des simulations de Monte-Carlo quantique, qui fournit des résultats numériquement exacts. Le premier modèle, appelé modèle de Kondo bosonique sur réseau, s’inscrit dans le contexte des atomes ultra-froids sur réseau. Nous trouvons que sa physique est proche de celle du modèle de Bose-Hubbard, présentant des phases de Mott et superfluide. Le couplage local renforce le caractère isolant et on observe l’émergence de phases magnétiques au travers de couplage direct ou indirect entre bosons et/ou spins. Les effets thermiques, inhérents à tout dispositif expériemental, sont aussi étudiés. Le second modèle s’inscrit dans le domaine de la CQED sur réseau, décrit un régime de couplage ultra-fort entre des photons et des atomes, et est appelé modèle de Rabi sur réseau. Le diagramme de phase présente juste deux phases : une phase cohérente dans laquelle les spins locaux s’ordonnent ferromagnétiquement ainsi qu’une phase incohérente compressible paramagnétiqueStrongly correlated systems, where new surprising phases of matter may appear both in the context of ultra-cold atoms and cavity quantum electrodynamics, are the focus of intense experimental and theoritical activity. In this thesis we present a study of two models of bosons with two or zero internal states, that is to say spin-1/2 or spin-0 bosons. These particles can move around a lattice, and they are locally coupled to immobile spins 1/2. Our interest was to determine the ground state phase diagram, study phase properties and quantum phase transitions. We used two methods: an approximate one using a mean field approach and the other using quantum Monte-Carlo simulations, which provides numerically exact results. The first model, namely the bosonic Kondo lattice model, is in the context of ultra-cold atoms in optical lattices. We found that its physics is close to that of the Bose-Hubbard model, exhibiting Mott and superfluid phases. The local coupling strengthens the insulating behaviour of the system and magnetism emerges through indirect or direct coupling between bosons. Thermal effects, inherent in experiments, are also studied. The second model, which is in the context of light-matter interaction, describes a situation of an ultra-strong coupling between spin-0 bosons (photons) and local spins 1/2 (two levels atoms) and is known as the Rabi lattice model. The phase diagram generally consists of only two phases: a coherent phase and a compressible incoherent one. The locals
33
Ferreiro, Rangel Carlos Augusto. "Molecular simulation studies in periodic mesoporous silicas SBA-2 and STAC-1 : model development and adsorption applications." Thesis, University of Edinburgh, 2011. http://hdl.handle.net/1842/5272.
Full textAbstract:
Adsorption is a low-energy separation process especially advantageous when the components to be separated are similar in nature or have a low molar concentration. The choice of the adsorbent is the key factor for a successful separation, and among them periodic mesoporous silicas (PMS) are of importance because of their pore sizes, shapes and connectivity. Furthermore, they can be modified by post-synthesis functionalisation, which provides a tool for tailoring them to specific applications. SBA-2 and STAC-1 are two types of PMS characterised by a three-dimensional pore system of spherical cages interconnected by a network of channels whose formation process was until now obscure. In this work the kinetic Monte Carlo (kMC) technique has been extended to simulate the synthesis of these complex materials, presenting evidence that the interconnecting network originates from spherical micelles touching during their close-packing aggregation in the synthesis. Moreover, for the first time atomistic models for these materials were obtained with realistic pore-surface roughness and details of the possible location of its interaction sites. Grand Canonical Monte Carlo (GCMC) simulations of nitrogen, methane and ethane adsorption in the materials pore models show excellent agreement with experimental results. In addition, their potential as design tools is explored by introducing surface groups for enhancing CO2 capture; and finally, application examples are presented for carbon dioxide capture from flue gases and for natural gas purification, as well as in the separation of n-butane / iso-butane isomers.
34
Palmer-Anghel, Cristina Ana-Maria. "On quantum Invariants : homological model for the coloured jones polynomials and applications of quantum sl(2/1)." Thesis, Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCC035/document.
Full textAbstract:
Le domaine de cette thèse est dans la topologie quantique et son sujet est axé sur l'interaction en- tre la topologie de basse dimension et la théorie des représentations. Ma recherche concerne as- pects différents des invariants quantiques pour les entrelacs et les $3$-variétés, visant a créer des ponts entre les façons algébriques et topologiques de les définir. D'une part, une description al- gébrique et combinatoire pour un concept mathématique, crée l'opportunité de développer des outils de calcul. D'un autre côté, les descriptions topologiques et géométriques ouvrent des per- spectives vers des constructions qui mènent a une compréhension plus profonde et a des théories plus subtiles.Les polynômes de Jones coloriés sont des invariants quantiques d'entrelacs contruits en partant de la théorie des représentations de $U_q(sl(2))$. Le premier invariant de cette séquence est le polynôme de Jones original, qui peut-être caractérisé aussi par la théorie de l'écheveau. Bigelow et Lawrence ont décrit un modèle homologique pour le polynôme de Jones. Ils ont utilisé la représentation de Lawrence, qui est une représentation de groupe de tresses sur l'homologie des revêtements d'espaces de configurations dans le disque pointé, et la nature de l'écheveau de l'in- variant pour la preuve. Contrairement a ce cas, les autres polynômes de Jones coloriés ne peu- vent pas être définis facilement par la théorie de l'écheveau.Dans la premiere partie de cette thèse, nous donnons un modèle topologique pour les polynômes de Jones coloriés. Nous utilisons leur définition comme invariants quantiques et construisons des correspondants topologiques pas à pas. Nous observons d'abord que l'invariant peut être codé par des espaces dits de plus haut poids, puis utiliser un résultat de Kohno, qui identifie ces espaces avec des représentations de Lawrence. Nous prouvons que les polynômes de Jones coloriés peu- vent être obtenus comme une forme d'intersection géométrique gradués entre des classes d'ho- mologie dans certaines couvertures des espaces de configuration de points dans le disque pointé.Les deuxième et troisième parties sont orientées vers les applications de la théorie de la représen- tation des super groupes quantiques aux invariants quantiques. La deuxième partie est une col- laboration avec N. Geer, ou nous construisons des invariants quantiques pour $3$-variétés a par- tir des représentations de $U_q(sl(2|1))$. Turaev-Viro ont défini une méthode de type somme d'état qui donne des invariants de $3$-variétés a partir de $ U_q(sl (2)) $. Pour les super groupes quantiques, cela entraîne l'annulation des invariants. Plus tard, Geer-Pa- tureau-Turaev ont défini une méthode modifiée qui commence par une catégorie avec de bonnes propriétés et conduit à des invariants non-nulls. Notre stratégie consiste a construire une caté- gorie qui peut-être utilisée dans cette méthode modifiée. La troisième partie concerne l'étude des algèbre centralisatrices pour les représentations de $ U_q (sl (2 | 1)) $. Wagner et Marin conjec- turaient les dimensions d'une suite d'algèbres centralisatrices correspondant à la représentation simple standard de $U_q(sl(2|1))$. Nous prouvons cette conjecture en utilisant des techniques combinatoiresThe domain of this thesis is within quantum topology and its subject is focused towards the interaction between low dimensional topology and representation theory. My research con- cerns different aspects of quantum invariants for links and $3$-manifolds, aiming to create bridges between algebraic and topological ways of defining them. On one hand, an algebraic and combinatorial description for a mathematical concept, creates the opportunity to develop computational tools. On the other hand, topological and geometrical descriptions open per- spectives towards constructions that lead to a deeper understanding and more subtle theories.The coloured Jones polynomials are quantum link invariants constructed from the representa- tion theory of $U_q(sl(2))$. The first invariant of this sequence is the original Jones polyno- mial, which can be characterised also by skein theory. Bigelow and Lawrence described a homological model for the Jones polynomial. They used the Lawrence representation, which is a braid group representation on the homology of coverings of configuration spaces in the punctured disk, and the skein nature of the invariant for the proof. In contrast to this case, the other coloured Jones polynomials cannot be defined in an easy manner by skein theory.In the first part of this thesis, we give a topological model for the coloured Jones polynomi- als. We use their definition as quantum invariants and construct step by step topological cor- respondents. We first observe that the invariant can be encoded through so-called highest weight spaces and then use a result by Kohno, which identifies these spaces with Lawrence representations. We prove that the coloured Jones polynomials can be obtained as graded geometric intersection pairings between homology classes in certain coverings of the config- uration spaces of points in the punctured disk.The second and third parts are oriented towards applications of representation theory of super quantum groups to quantum invariants.The second part is a collaboration with N. Geer, where we construct quantum invariants for$3$-manifolds from representations of $U_q(sl(2|1))$. Turaev-Viro defined a state-sum type method that gives $3$-manifold invariants from $U_q(sl(2))$. For super quantum groups, this leads to vanishing invariants. Later on, Geer-Patureau-Turaev defined a modified method which starts with a category with good properties and leads to non-vanishing invariants. Our strategy is to construct a category that fits into the input of this modified method.The third part concerns the study of centralizer algebras for representations of $U_q(sl(2|1))$. Wagner and Marin conjectured the dimensions of a sequence of centralizer algebras corre- sponding to the simple standard $U_q(sl(2|1))$-representation. We prove this conjecture us- ing combinatorial techniques
35
Bagci, Mediha Ozlem. "An Analysis Of The Thermal Performance Of Metu Staff Housing Units And Calibration Of Their Simulated Model." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/2/12609616/index.pdf.
Full textAbstract:
The aim of this study was to investigate the thermal performance of residential units in the Middle East Technical University (METU) Campus, Ankara. The study was conducted on the unoccupied residential units to eliminate the occupant interventions. There were only three unoccupied residential units in the study period, hence sample was considered as randomly selected. Case study units were triplex row houses and all physical characteristics were identical apart from their orientations. The thermal performance of these three residential units was assessed by compiling data on temperature and relative humidity from a number of their rooms on certain days in January and February. The study was conducted in winter months, because heating loads are more significant than cooling loads for energy consumption in Ankarathe measurement period was determined according to the coldest days of the year. In this context, the temperature and humidity charts were evaluated and one of the units was simulated using the software tool Ecotect v.5.20. The simulation temperature charts demonstrate similar behavior and trends as the measured temperature
although, it was approximately 4 0C lower than the measured temperature. The possible reason for such a difference may be the precision of the material properties. Six different calibrations were tested by changing the thermal properties of the envelope materials to obtain comparable results with the measured temperature readings. Based on the calibrated model, it was found that an increase in the U-value of the envelope materials did not have a significant effect on the simulated temperature charts.
36
Lugo-González, Isaías Vicente, Yuma Yoaly Pérez-Bautista, Ana Leticia Becerra-Gálvez, Margarita Fernández-Vega, and Leonardo Reynoso-Erazo. "Percepción emocional del COVID-19 en México: Estudio comparación entre la fase 1, fase 2 y medios de información." Instituto Peruano de Orientación Psicológica, 2021. http://hdl.handle.net/10757/656798.
Full textAbstract:
Introducción: Desde el registro de los primeros casos de COVID-19 en México, se han derivado una serie de respuestas emocionales caracterizadas por miedo y estrés. Dicho impacto emocional se debe en gran medida a la inundación de información paralela a las fases de la pandemia y la transición entre ellas y la percepción que los individuos tienen de la enfermedad. El objetivo del presente trabajo fue comparar la percepción del COVID-19 entre la fase 1 y 2 de la pandemia y entre los medios de información usados para informarse en población mexicana. Métodos: Considerando un muestreo en cadena, se realizó un estudio comparativo en el que se diseminó por medio de correo electrónico y redes sociales una batería de evaluación que respondieron 1560 participantes. Resultados: La preocupación por las consecuencias del COVID-19 y su impacto emocional incrementaron al pasar de la fase 1 a la fase 2 de la pandemia. Además, se identificó que el impacto emocional fue mayor en quienes se informaron a través de Facebook® y televisión. Conclusiones: La pandemia tendrá un impacto emocional progresivo en medida en que avancen sus fases y en la importancia de informarse en medios adecuados para prevenir consecuencias emocionales.
37
Inan, Cem. "Development Of A Ventilation Model For The G Field Of Cayirhan Coal Mine." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/2/12605865/index.pdf.
Full textAbstract:
Ventilation problems raised with the beginning of underground mining. In underground mining, to provide safe and healthy working conditions, ventilation should be designed properly. Especially in the planning stage of the project, to design ventilation properly is very important.
The latest upgrade of the popular ventilation simulation program, known as VnetPC 2000, has been applied for the ventilation design.
In this study simulation is conducted to both auxiliary and main ventilation at Çayirhan G Field. Information describing the geometry of a ventilation network, airway characteristics and locations, characteristics of different fans were prepared as an input. The output includes predicted airflows, frictional pressure drops, air power, losses in airway and fan operating points for different trials. After different trials it has been found that for auxiliary ventilation, where minimum required amount of air is 6 m3/s, ENGART, 30A 40SCV/60HR model fan which is the most economical one was selected. For main ventilation system, 5 fans which provide airflow more than minimum requirement were chosen. Among them the most economical one, that is ALPHAIR-5400VAX2100 HB, was selected for the mine.
38
Chaboussant, Grégory. "Étude expérimentale d'une échelle de spin-1/2 antiferromagnétique : Cu2(C5H12N2)2Cl4." Université Joseph Fourier (Grenoble ; 1971-2015), 1997. http://www.theses.fr/1997GRE10007.
Full textAbstract:
Ce memoire presente une etude experimentale d'un compose organique isolant ayant des proprietes magnetiques unidimensionnelles (1d): cu#2(c#5h#1#2n#2)#2cl#4. C'est un systeme antiferromagnetique de heisenberg s=1/2 en echelle de spins. Les interactions d'echanges entre les electrons non apparies des ions cu#2#+ forment une structure magnetique en echelle que l'on peut decrire par deux parametres d'echanges, j entre les barreaux et j le long des deux chaines. Comme toutes les echelles de spin-1/2 ayant un nombre pair de chaines couplees, ce systeme a un gap d'energie dans le spectre des excitations. Les proprietes de l'etat fondamental et, dans une certaine limite des etats excites, sont alors similaires a celles des chaines de haldane (s=1). A contrario les echelles comportant un nombre impair de chaines sont critiques (sans gap) et appartiennent a la meme classe d'universalite que les chaines de spin-1/2 dont la solution est donnee par l'ansatz de bethe. Cette these presente une etude assez complete des proprietes thermodynamiques et dynamiques de ce compose. Les mesures thermodynamiques ou statiques reposent sur l'utilisation de magnetometres squid ou, pour les champs magnetiques intenses, d'oscillateurs torsionnels a haute resolution. Les techniques de resonance electronique de spin (rpe) dans la gamme micro-ondes et de resonance magnetique nucleaire sur le proton ont ete utilisees pour etudier les proprietes dynamiques liees aux fonctions de correlations telle que la largeur de raie rpe ou le temps de relaxation nucleaire spin-reseau t#1. Nous avons determine l'ensemble des parametres essentiels lies au magnetisme de ce compose: cu#2(c#5h#1#2n#2)#2cl#4 est decrit par un hamiltonien de heisenberg dont les interactions d'echanges forment une echelle de spins dans la limite de couplage fort: j 13. 2k et j 2. 5k. Le gap d'energie entre l'etat fondamental non-magnetique s=0 et les etats excites triplets (s=1) est 10. 5k
39
Baser, Erkan. "Visual Tracking With Motion Estimation And Adaptive Target Appearance Model Embedded In Particle Filtering." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/2/12610092/index.pdf.
Full textAbstract:
In this thesis we study Particle Filter for visual tracking applications. The sequential Monte Carlo methods or Particle Filter provides approximate solutions when the tracking problem involves non-linear and/or non-Gaussian state space models. Also in this study, in order to make the visual tracker robust against change in target appearance and unexpected target motion, an adaptive target appearance model and
a first order motion estimator are embedded in particle filtering. Additionally, since pixels that don&rsquot belong to target makes the motion estimation biased, the algorithm includes robust estimators to make the tracker reliable. Within the scope of this thesis the visual tracker proposed in [5] is implemented and the same problem is solved by proposing a Rao-Blackwellized Particle Filter. To deal with problems encountered during the implementation phase of the algorithm some improvements are made such as utilizing learning rate for the computation of adaptive velocity estimation. Moreover, some precautions are taken such as checking the velocity estimations to validate them. Finally, we have done several experiments both in indoor and outdoor environments to demonstrate the effectiveness and robustness of the implemented algorithm. Experimental results show that most of the time the visual tracker performs well. On the other hand the drawbacks of the implemented tracker are indicated and we explain how to eliminate them.
40
Hurley, Margaret M. "Analysis of the dipolar lattice gas as a model for self-assembly in 1 and 2-dimensional systems /." The Ohio State University, 1992. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487780393265179.
Full text
41
Buntine, James D. Saffman P. G. "Part 1. Inviscid, swirling flows and vortex breakdown. : Part 2. A numerical investigation of the Lundgren turbulence model /." Diss., Pasadena, Calif. : California Institute of Technology, 1994. http://resolver.caltech.edu/CaltechETD:etd-10182005-082716.
Full text
42
Nixdorf, Timothy Allen. "A Mathematical Model for Carbon Nanoscrolls." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1406060123.
Full text
43
Müller, Uwe. "Umfassende klassische Analyse des geeichten SL(2,R)-U(1)-Wess-Zumino-Novikov-Witten-Modells." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 1998. http://dx.doi.org/10.18452/14525.
Full textAbstract:
Zusammenfassung In den letzten Jahren haben Schwarze Löcher viel Aufmerksamkeit auf sich gezogen, insbesondere wegen ihrer ungewöhlichen quantentheoretischen Eigenschaften. Ein in diesem Zusammenhang interessantes Modell ist das geeichte SL(2,R)/U(1)-Wess-Zumino-Novikov-Witten-Modell, das im Rahmen der Stringtheorie als Euklidisches zweidimensionales Schwarzes Loch interpretiert werden kann. Die vorliegende Arbeit analysiert die klassischen Eigenschaften dieses Modells, um so die Grundlage für quantentheoretische Untersuchungen zu schaffen. Ausgangspunkt ist eine allgemeine Betrachtung über geeichte Wess-Zumino-Novikov-Witten-Modelle (WZNW-Modelle). Herkömmlicherweise werden sie mit Hilfe von Eichfeldern formuliert, deren Bewegungsgleichungen rein algebraisch sind. In der vorliegenden Arbeit werden die Eichfelder aus den Modellen eliminiert. Dabei entsteht eine Klasse von nichtlinearen integrablen konformen Feldtheorien, für deren Bewegungsgleichung eine explizite Lax-Paar-Darstellung abgeleitet wird. Diese Ergebnisse werden auf das geeichte SL(2,R)/U(1)-WZNW-Modell spezialisiert. Zum Vergleich wird auch die Eliminierung des Eichfeldes durch explizite Pfadintegration untersucht, die jedoch aufgrund mathematischer Ambiguitäten nicht zu einem abschließenden Ergebnis geführt wird. Das klassische geeichte SL(2,R)/U(1)-WZNW-Modell wird sowohl in einem unendlich ausgedehnten Minkowski-Raum als auch mit räumlich periodischen Randbedingungen untersucht. Letzteres ist für die stringtheoretische Interpretation des Modells wichtig. Es werden die nichtlinearen Bewegungsgleichungen und ihre allgemeine Lösung angegeben. Diese enthält Parameterfunktionen. Es wird ein Verfahren abgeleitet, um die Parameterfunktionen aus vorgegebenen Anfangsbedingungen zu bestimmen. Mit Hilfe dieses Verfahrens werden die Poissonklammern der Parameterfunktionen aus den kanonischen Poissonklammern der physikalischen Felder berechnet. Es wird gezeigt, daß es eine nichtlokale kanonische Transformation der nichtlinearen physikalischen Felder auf freie Felder gibt. Die entsprechende Bäcklund-Transformation wird angegeben.Abstract In recent years, Black Holes have attracted much attention, in particular, because of their unusual quantum-theoretical properties. An interesting model, in this context, is the SL(2,R)/U(1) gauged Wess-Zumino-Novikov-Witten model, which can be interpreted stringtheoretically as Euclidean two-dimensional Black Hole. The present dissertation analyzes the classical properties of this model, in order to prepare the basis for quantum-theoretical investigations. First, gauged Wess-Zumino-Novikov-Witten (WZNW) models are intoduced in general. Usually, they are formulated including gauge fields, whose equations of motion are purely algebraic. In the present dissertation, the gauge fields are eliminated from the models. A class of non-linear integrable field theories arises, whose equations of motion can be represented by Lax pairs explicitly. These results are specialized to the SL(2,R)/U(1) gauged WZNW model. For comparison, the elimination of the gauge field by explicit path integration is also investigated. But due to mathematical ambiguities, this investigation does not lead to a final result. The classical SL(2,R)/U(1) gauged WZNW model is investigated in an infinitely extended Minkowski space-time as well as with spatially periodic boundary conditions. The latter is important for the stringtheoretical interpretation of the model. The non-linear equations of motion and their general solution are given. A procedure is derived to determine the parameter functions of the general solution from given initial conditions of the equations of motion. By means of this procedure the Poisson brackets of the parameter functions are calculated from the canonical Poisson brackets of the physical fields. It is shown that there is a non-local canonical transformation of the non-linear physical fields onto free fields. The corresponding Backlund transformation is presented.
44
Šindelářová, Šárka. "Procesní model organizace." Master's thesis, Vysoká škola ekonomická v Praze, 2012. http://www.nusl.cz/ntk/nusl-165131.
Full textAbstract:
This thesis covers with the topic of process management and organization modeling. The goal is to design a future state of process architecture in selected department of a multi-national company, which is based on ISO / IEC TR 29110-5-1-2:2011 for very small entities, complemented by techniques of agile methodologies. The final form of the future proposal includes the conceptual and detail design according to the aforementioned standard, supported by the selected agile techniques, adjusted for the results of the differential analysis of conceptual and detail design and current status. The theoretical part presents the issue of process management and modeling standards and a methodology for modeling and control of IT processes. The practical part is devoted to the application of the selected standard for IT management processes and agile techniques that support this standard. The proposed process architecture is modeled using the selected methodology MMABP and prescribed standards. The work can serve as an inspiration for the company that would be suited a combination of traditional and agile approaches to IT.
45
Musta, Mustafa Nail. "Implementation Of Turbulence Models Into A Navier-stokes Solver." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/2/12605357/index.pdf.
Full textAbstract:
In order to handle turbulent flow problems, one equation turbulence models are implemented in to a previously developed explicit, Reynolds averaged Navier-Stokes solver. Discretization of Navier-Stokes solver is based on cell-vertex finite volume formulation combined with single step Lax-Wendroff numerical method which is second order accurate in space. Turbulent viscosity is calculated by using one equation Spalart-Allmaras and Baldwin-Barth turbulence transport equations. For the discretization of Spalart-Allmaras and Baldwin-Barth equations, both finite volume scheme which is used for Navier-Stokes equation in this work and explicit finite difference discretization method are used.
In order to increase the convergence rate of the solver, local time stepping technique is applied. Stabilization of non-physical oscillations resulting from the numerical scheme is maintained by adding second and fourth order artificial smoothing terms.
Three test cases are considered. In order to validate the accuracy of the Navier-Stokes solver, solver is tested over a laminar flat plate. The results are compared with analytical solutions. Later, in order to check the performance of the turbulence models, turbulent flow over flat plate and turbulent transonic flow over NACA-0012 airfoil are handled. For turbulent flow over flat plate obtained results are compared with analytical and empirical solutions, whereas for transonic turbulent flow obtained results are compared with numerical and experimental solutions.
46
Navarro, Serer Judith 1990. "Understanding functional interplay between PARP-1 and PARP-2 in T cell development and function." Doctoral thesis, Universitat Pompeu Fabra, 2016. http://hdl.handle.net/10803/481994.
Full textAbstract:
T-cell homeostasis must be tightly regulated and maintained in order to guarantee appropriate immune responses and prevent immunopathology. This maintenance depends on MHC-TCR interaction and cytokine-mediated signals among others. However, cell intrinsic factors that modulate essential functions in T-cells must be also integrated to support genomic stability and contribute to the control of T-cell homeostasis.
The present work establishes a coordinated role of poly (ADP-ribose) polymerase-1 (PARP-1) and PARP-2 in maintaining T-lymphocyte number and function, demonstrated by the defective thymocyte maturation and diminished numbers of peripheral CD4+ and CD8+ T cells in mice bearing a T-cell specific deletion of PARP-2 in a PARP-1-deficient background. Moreover, this T-cell lymphopenia is associated with an increased DNA-damage and concomitant cell death, leading to highly aggressive spontaneous T-cell lymphomas in PARP-1/PARP-2 double-deficient mice.
Our findings highlight the importance of understanding the specific involvement of both proteins in key biological processes that could have an impact on the development and exploitation of PARP-inhibitors.L’homeòstasi de la cèl·lula T ha d’estar estrictament regulada per tal de garantir una correcta resposta immunitària i prevenir alhora qualsevol problema immunopatològic. Aquest correcte manteniment depèn, entre d’altres, de la interacció amb el complex MHC-TCR i de les senyals de diferents interleuquines. No obstant, hi ha altres factors intrínsecs que intervenen en la modulació de les funcions vitals de la cèl·lula T i que han d’estar també correctament integrats en tot el sistema per tal de garantir una correcta estabilitat genòmica i contribuir en el control de l’homeòstasi de la cèl·lula T. El present treball estableix el paper coordinat entre els enzims poli (ADP-ribosa) polimerasa-1 (PARP-1) i PARP-2 en el manteniment del nombre i la funció dels limfòcits T, tal i com es demostra amb el defecte en maduració i el descens en el número de cèl·lules CD4+ i CD8+ perifèriques que tenen els ratolins amb deleció de PARP-2 en un background PARP-1 deficient. A més a més, aquesta limfopènia està associada amb un increment del dany en el ADN i una concomitant mort cel·lular, que condueix al desenvolupament espontani de limfomes T molt agressius en els ratolins dobles deficients per PARP-1 i PARP-2. Els nostres resultats posen de manifest la importància de conèixer correctament el paper específic de les dues proteïnes en processos biològics rellevants, ja que podria tenir especial impacte en el desenvolupament i l’explotació dels inhibidors PARP.
47
Ody, Michael S. "The (2+1)-dimensional non-linear O(3) sigma model and the classical differential geometry of curves and surfaces." Thesis, University of Kent, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358169.
Full text
48
Sakinc, Mustafa Erdem. "Finance Of The Software Industry In Turkey." Master's thesis, METU, 2009. http://etd.lib.metu.edu.tr/upload/2/12610818/index.pdf.
Full textAbstract:
This thesis aims to explore the challenges of ICT industries to have access to financial sources in Turkey. The specific subject of analysis is the Turkish software industry. First, it is identified that the global course of the science and technology policies and economic developments are intertwined and they are the major determinants of the current situation of high-tech sectors and their finance all over the world. The importance of finance is based on its association with the innovativeness of high-tech firms. The financial commitment is crucial for firms to sustain innovative activities before revenue generation. Today there is a widely used mainstream model of financial growth cycle defining the sources of finance and the specific needs of high-tech firms along their growth paths. Second, the historical course of finance in Turkey are analyzed and milestones of science and technology policies as well as the development of ICT industries are briefly discussed in order to exhibit the underlying structure of the present issues of high-tech sectors&rsquofinance in Turkey. Later, the growth cycle model is implemented for Turkey to analyze the potential of financial sources for Turkish software firms with relevant quantitative data. It is seen that the interest of available financial sources towards high-tech sectors is limited and unconcerned. In addition, an inquiry for the finance of the software industry is also done through the analysis of interviews performed with managers of software firms and several funding organizations. Instabilities and uncertainties of the Turkish economy, underdevelopment of a national strategy on software and the lack of interest of available financial sources towards software industry are the major handicaps for the growth of software firms and the industry as a whole. A selective national industrial strategy on software is crucial for the true allocation of financial resources towards software firms.
49
Philips, Julia Rachel. "B-1 and B-2 B cell responses to lipopolysaccharide putative roles in the pathogenesis of periodontitis /." University of Sydney, 2006. http://hdl.handle.net/2123/1852.
Full textAbstract:
Master of SciencePeriodontal disease is one of the most widespread diseases in humans and is characterised by chronic gingival inflammation and B cell accumulation and resorption of the crest of alveolar bone with subsequent loss of teeth. Porphyromonas gingivalis has been identified as a putative aetiological agent for periodontitis. The aim of the research presented in this thesis was to investigate, using in vitro systems, the responses of autoreactive B-1 and B-2 cells to enterobacterial and nonenterobacterial lipopolysaccharide (LPS) to shed light on the pathogenesis of chronic periodontitis and other diseases involving B cell accumulation and autoantibody production. The hypotheses tested were: (1) B cells respond differently to enterobacterial and non-enterobacterial LPS. (2) B-1 cells are activated by a lower concentration of LPS than B-2 cells. (3) LPS stimulation results in preferential accumulation of B-1 cells. Findings consistent with these hypotheses would provide new evidence for different roles for B-1 and B-2 cells in immune responses and that LPS stimulation could lead to B-1 cell accumulation in diseases thus characterised. Initial experiments investigated the responses of representative B-1 (CH12) and B-2 (WEHI-279) cell lines to preparations of P. gingivalis and Salmonella enteritidis LPS utilising flow cytometric and quantitative molecular methods. The cell lines responded differently to the two LPS preparations. There were significant but limited effects on viability and proliferation in the WEHI-279 cell line, but no significant changes in mRNA expression levels for genes including Toll-like receptors (TLR2, TLR4, RP105), immunoglobulin (IgM), cytokines (IL-6, IL-10), co-stimulatory molecules (CD80, CD86), and regulators of apoptosis (Bcl-2, Bax). In the CH12 cell line however, LPS stimulation had greater effect. Addition of S. enteritidis LPS from a threshold level of 100ng/mL was found to rescue the cells from death, reflected by the percentage viability and proliferation. Stimulation of CH12 cells with S. enteritidis LPS also led to a decrease in expression of RP105 mRNA, which may be part of a negative feedback loop. Interestingly, stimulation with low concentrations P. gingivalis LPS appeared to inhibit proliferation but high LPS concentrations stimulated proliferation of CH12 cells, although no further significant effects were noted in other analyses. Evidence was found that CH12 cells have a high basal level of activation. This suggests that this line is constitutively activated. Stimulation with P. gingivalis or S. enteritidis LPS did not affect the level of CD80 mRNA expression. It is possible that the CH12 line constitutively expresses a maximal level of CD80 (and possibly CD86) and further stimulation will not cause any increase. Since S. enteritidis LPS appeared to have more pronounced effects on both B cell populations, this LPS was used to further investigate B cell subset responses in a mixed splenocyte culture system. Experiments examining percentage viability and number of viable cells indicated that B-1 and B-2 B cells responded differently to LPS stimulation. A threshold level for B-2 cell response (significant increase in cell number) was found to be 100ng/mL LPS, in contrast to the B-1 B cell subset which were only significantly different to the unstimulated cells when stimulated with 50μg/mL LPS. By examining the expression of CD80, the majority of murine splenic B-1 cells were found to activated prior to any LPS stimulation in vitro. In contrast, the B-2 subset showed significant increase in CD80 expression only at high (≥10μg/mL) LPS concentrations. Studies of the division index of B-1 and B-2 cells showed a significant response in both subsets following stimulation with 1μg/mL and 10μg/mL LPS. However, overall, the results are inconsistent with LPS driving the preferential accumulation of B-1 cells in disease states. These experiments provided useful evidence that supported the idea that B-1 and B-2 cells respond differently to LPS. However, these studies were unable to directly address the role of P. gingivalis LPS in periodontitis. It may be that P. gingivalis LPS could have different effects to S. enteritidis LPS on primary B cells. It is still possible that B-1 cells may be more sensitive to P. gingivalis, as opposed to S. enteritidis LPS. Studies by other groups have suggested that the TH1/TH2 profile is skewed towards TH2 in chronic periodontitis and that P. gingivalis may drive this shift via its ability to signal through TLR2 (and modulate TLR4 signalling). Further, recent studies in our laboratories have found that P. gingivalis gingipains are able to polyclonally activate B cells and to break down both IFNγ and IL-12. Future studies should further examine the effects of B-1 and B-2 interactions in the mixed lymphocyte system together with subsequent studies utilising human periodontitis biopsies. The results presented in this thesis, together with work undertaken by other investigators, suggests that LPS could perturb the normal homeostatic mechanisms of the B-1 B cell-subset and increase polyclonal activation therefore contributing to the genesis of pathologies such as chronic periodontitis.
50
Wijesiri, Narayana Don Nimal Wijesiri. "Representation of identity in Sinhala theater: The impact of the religious/charity model." Thesis, Queensland University of Technology, 2022. https://eprints.qut.edu.au/235387/1/Nimal%2BWijesiri%2BThesis%2B%282%29.pdf.
Full textAbstract:
This study used a critical disability studies analysis of historical and contemporary theatre work, informed by interviews with theatre practitioners and spectators to understand how disability, ethnic, racial, gender, and sexual identity is being representing in Sinhala theatre in Sri Lanka. The thesis explored how theatre practitioners and audiences want to see identity representations evolve in future, to create change in Sri Lankan society.