A perda ou falha de um órgão ou tecido é um dos problemas mais severos da saúde humana. A engenharia de tecidos, definida como o cultivo e adesão de células humanas in vitro em um scaffold ou arcabouço, surge como uma alternativa viável para reposição de órgãos e tecidos. Estas células proliferam, migram e se diferenciam num tecido específico enquanto produzem os componentes de matriz extracelular (ECM) necessários para criar este tecido. A obtenção de scaffolds fibrosos a partir da blenda polimérica de Poli (Ácido Láctico-co-Glicólico) (PLGA) e Poliisopreno (PI) é proposta como uma alternativa à engenharia de tecidos moles. Este material foi processado como estrutura fibrosa por meio de métodos de gotejamento (FD) e electrospinning (FS). Caracterização físico-química foi aplicada à blenda e às fibras geradas. Também foi averiguada a viabilidade das fibras em culturas de mioblastos murinos, fibroblastos dérmicos humanos, condrócitos bovinos e hepatocarcinomas. Nota-se que o processo de obtenção da blenda não apresentou alterações na estrutura química dos polímeros, sendo apontada também a imiscibilidade entre eles. A ductilidade do material foi apontada como efeito da presença de PI na blenda, embora esta composição apresente similar molhabilidade entre a mistura e os polímeros puros. As fibras geradas por electrospinning geraram um scaffold com menor porosidade do que as fibras obtidas por gotejamento, mesmo apresentando um diâmetro menor e uma orientação paralela entre fibras. As fibras obtidas por gotejamento apresentaram fibras emaranhadas de maior diâmetro, mas maior tammanho de poros, gerando scaffolds de maior porosidade. As propriedades mecânicas de ambos scaffolds indicam sua aplicação enquanto substitutos de tecidos moles. Ensaios de viabilidade celular condenaram o uso das fibras FS, uma vez que estas apresentaram solvente residual no interior da fibra, causando indesejada lise celular. As fibras FD apresentaram resultados de adesão e proliferação adequados para mioblastos, fibroblastos e condrócitos, porém os resultados foram considerados impróprios para hepatócitos. / The lost or failure of an organ or tissue is one of the most severe problems in human health. Tissue engineering, defined as the seeding and adhesion of human cells in vitro over a scaffold, arises as an viable alternative for reproduction of organs and tissues. These cells proliferate, migrate and differentiate into a specific tissue while producing extracellular matrix components. The obtaining of fibrous scaffolds from a polymeric blend of Poly (Lactic-co-Glycolic Acid) (PLGA) and Polyisoprene (PI) is proposed as an alternative to soft tissue engineering. This material was processed as a fibrous structure through dripping (FD) and electrospinning (FS) methods. Physical-chemical characterization was applied to the blend and to the generated fibres. Fibres viability was also observed for murine myoblasts, human dermal fibroblasts, bovine chondrocytes and hepatocellular carcinoma cultures. It was noticed that the blending process didn't have any influence over polymer's chemical structure, being observed the immiscibility between the raw materials. Blend's ductile behaviour was pointed out as an effect of PI presence, although this mixture presents similar wettability to the one presented by these raw polymers. Fibres obtained by electrospinnig generated a scaffold with smaller porosity, even presenting fibres with smaller diameter and a parallel organized topography. The fibres obtained by dripping presented a tangled structure of thicker fibres, but assembling a scaffold with higher porosity and inner space. Mechanical properties of both scaffolds indicate their applicability as soft tissue substitutes. Cell viability assays condemn the use of FS fibres, seen that they present residual solvent trapped into the fibre, causing undesirable cell lysis. On the other hand, FD fibres presented positive adhesion and proliferation results for myoblasts, fibroblasts and chondrocytes cell lines, however the results were consider inappropriate for hepatocytes.

With the recent advancements in High Performance Computing (HPC), it is possible to rapidly process high volumes of data, allowing accomplishments in several areas of knowledge. Although the HPC area has been observed as an area of complex infrastructure, in the last years, its been observed that the processing power of processors used in embedded systems, using the ARM architecture, has been increasing significantly. Furthermore, the acquisition costs and energy consumption are lower, when compared to processors of other platforms, thus allowing for the possibility of having HPC with smaller and more economical platforms, with lower maintenance cost and more accessible. In this merit, this masters thesis proposes the performance analysis of a low cost embedded cluster composed of processors using ARM architecture and the Raspberry Pi platform. This work analysis the impact of using MPICH-2 and OpenMPI libraries, running benchmark programs HPCC and HPL. The present work show results of performance and energy consumption of this cluster with these programs, proving that it is possible to use clusters of low cost embedded platforms with satisfactory speedups and energy consumption. / Com o desenvolvimento da computação de alto desempenho (HPC), grandes volumes de dados passaram a ser processados de forma rápida, permitindo assim, que avanços significativos fossem alcançados em varias áreas do conhecimento. Para isso, sempre se observou a área de HPC tendo uma infraestrutura complexa. Por outro lado, nos últimos anos, se observa que a capacidade de processamento dos processadores usados em sistemas embarcados, seguindo arquitetura ARM, vem aumentando de forma significativa. Além disso, os custos de aquisição e o consumo de energia dos processadores ARM são menores, quando comparados a processadores de outras plataformas. Neste âmbito, cria-se a possibilidade de ter HPC usando plataformas menores e mais econômicas e com um custo de manutenção mais acessível. Nesse intuito, esta dissertação de mestrado, propõe a análise de desempenho de um cluster embarcado de baixo custo composto por processadores da arquitetura ARM e plataforma Raspberry Pi. O trabalho analisa o impacto de usar as bibliotecas MPICH-2 e OpenMPI, executando os programas dos benchmarks HPCC e HPL. O trabalho apresenta resultados de desempenho e consumo de energia do cluster com esses programas, mostrando que é possível usar clusters de plataformas embarcadas de baixo custo e tendo speedups e consumo de energia satisfatórios.

The use of Intrusion Detection Systems is a normal thing today in bigger companies, butthe solutions that are to be found in market is often too expensive for the smallercompany. Therefore, we saw the need in investigating if there is a more affordablesolution. In this report, we will show that it is possible to use low cost single boardcomputers as part of a bigger centralized Intrusion Detection System. To investigate this,we set up a test system including 2 Raspberry Pi 3 Model B, a cloud server and the use oftwo home networks, one with port mirroring implemented in firmware and the other withdedicated span port. The report will show how we set up the environment and the testingwe have done to prove that this is a working solution.

Context. Name-bounded analysis is a type of static analysis that allows us to take a concurrent program, abstract away from it, and check for some interesting properties, such as deadlock-freedom, or watching the propagation of variables across different components or layers of the system. Objectives. In this study we investigate the difficulties of giving a representation of computer programs in a name-bounded variation of π-calculus. Methods. A preliminary literature review is conducted to assess the presence (or lack thereof) of other successful translations from real-world programming languages to π-calculus, as well for the presence of relevant prior art in the modelling of concurrent systems. Results. This thesis gives a novel translation going from a relevant subset of the Java programming language, to its corresponding name-bounded π-calculus equivalent. In particular, the strengths of our translation are being able to dispose of names representing inactive objects when there are no circular references, and a transparent handling of polymorphism and dynamic method resolution. The resulting processes can then be further transformed into their Petri-Net representation, enabling us to check for important properties, such as reachability and coverability of program states. Conclusions. We conclude that some important properties that are not, in general, easy to check for concurrent programs, can be in fact be feasibly determined by giving a more constrained model in π-calculus first, and as Petri Nets afterwards. / +49 151 52966429

La synthèse de chromophores organiques comme composants de matériaux pour l'optique non-linéaire a été le point central d'un grand nombre de recherches, en raison de leur utilisation potentielle dans les domaines des communications optiques, du traitement de l'information, de l'imagerie… Le plus souvent, les molécules possédant de fortes valeurs d'hyperpolarisabilité [bêta] sont constituées d'un couple de groupements donneur-accepteur connecté par le biais d'un système [pi]-conjugué. Celles comportant des hétérocycles comme motifs centraux ont reçu une attention considérable dans le domaine de l'optique non-linéaire en raison de leur relative facilité de préparation et de la variation de leur degré de polarité. A ce titre, nous nous sommes intéressés à la conception de nouvelles molécules ayant la structure précédemment décrite. Les variations structurales ont porté sur le groupement donneur (alkoxy, dialkylamino porté par un cycle aromatique), le groupement accepteur (dicyanovinyle, acide cyanoacrylique et acide thiobarbiturique) et le système [pi]-conjugué (thiophène, thiéno[3,2-b]thiophène et bithiophène). Les propriétés optiques de ces composés ont été étudiées et ont permis d'établir quelques liens entre certaines modifications structurales et les propriétés optiques. Les fortes valeurs de [bêta] obtenues montrent clairement le potentiel des composés préparés et permettent d’envisager d’autres modifications structurales afin d'encore améliorer ces valeurs / The synthesis of organic compound as components of materials for nonlinear optics has been the focus of many researches because of their potential uses in the fields of optical communications, information process, imagery ... Most often, the molecules with strong hyperpolarizabilitie [bêta] values incorporate a pair of donor-acceptor groups connected via a [pi] -conjugated system. Those containing heterocycles motifs received considerable attention in the field of nonlinear optics due to their relative facility of preparation. We are interested in designing of new molecules with the structure previously described. The structural changes have focused on the donor group (alkoxy, dialkylamino carried by an aromatic ring), the acceptor group (dicyanovynil, cyanoacrylic acid and thiobarbituric acid) and [pi]-conjugated system (thiophene, thieno[3,2-b]thiophene and bithiophene). The optical properties of these compounds have been studied and we have established some links between some structural changes and optical properties. The high values of [bêta] obtained clearly show the potential of compounds prepared and used to explore other structural modifications to improve these values

Orientadores: Osvaldir Pereira Taranto, Flavio Vasconcelos da Silva / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-07T20:04:54Z (GMT). No. of bitstreams: 1 Pavanelli_PaulaEdilene_M.pdf: 1842381 bytes, checksum: ae8746d54834e8c938141f3e78903477 (MD5) Previous issue date: 2006 / Resumo: Este trabalho apresenta o controle e monitoramento em tempo real do regime de jorro estável através do método de identificação dos regimes de contato gás-sólido por medidas de pressão no leito de jorro. O trabalho foi realizado em duas etapas: 1) identificação em tempo real dos regimes fluidodinâmicos no processo em leito de jorro baseada na análise espectral das flutuações de queda de pressão do leito e 2) controle do processo em regime estável por malha PI. O sistema constitui-se de um leito construído em acrílico com dimensões de 0,70m de altura de coluna e 0,143m de diâmetro interno, operando com três diferentes partículas, esferas de vidro (dp = 2,59mm e Pp = 2,487 g/cm3), poliestireno (dp = 2,19mm e Pp = 1,196 g/cm3) e ABS (dp = 3,08mm e Pp = 1,029 g/cm3). Determinou-se a faixa da freqüência dominante 7,2-7,9 Hz, característico do regime de jorro estável, através do algoritmo da Transformada Rápida de Fourier (FFT) para cada partícula. Todas as medidas de pressão do leito durante o processo foram coletadas pelo sistema de aquisição através da placa PCI 6024E (National Instruments) utilizando o software LabView 7.1TM. Com o intuito de controlar o regime de jorro estável no processo em leito de jorro foram definidas como variáveis controlada e manipulada a freqüência dominante do espectro de potência (Hz) e o sinal de comando para o inversor de freqüência (V), respectivamente. A freqüência dominante foi determinada pela análise espectral das flutuações de queda de pressão no leito. O sinal de comando para inversor de freqüência atuava na variável de processo vazão de ar. Aplicaram-se perturbações degrau em malha aberta na variável manipulada para determinar os parâmetros do controlador e implementou-se a malha de controle no processo. Nos experimentos em malha fechada foram aplicadas perturbações na carga como adição de partículas e alteração na posição de abertura da válvula de ar de entrada no leito afim de testar o desempenho do controlador. Os resultados obtidos mostraram que o controlador PI manteve o sistema operando em regime estável mesmo quando aplicadas perturbações na carga, atingindo assim o objetivo do trabalho proposto / Abstract: This work describes the control and on line monitoring of the spouted bed steady regime using the gas-solid contact regimes identification method by pressure measurements. The work presents two main features: 1) the on line identification of fluid dynamic regimes in the spouted bed process based in the spectral analysis of the pressure fluctuations and 2) the process control using PI controllers. Experiments were performed in an acrylic cylindrical column 0.70m high and with 0.143m of internal diameter. The bed was made of three different particles: glass spheres (dp = 2.59mm and Pp = 2.4873 g/cm3), polystyrene (dp = 2.19mm and Pp = 1.1962 g/cm3) and ABS (dp = 3.08mm and p = 1.0286 g/cm3). The dominant frequency band was determined: 7.2-7.9 Hz for steady regime, through the algorithm of the Fast Fourier Transform (FFT), for each particle. All the measurements of pressure during the process were collected by a data acquisition system and using software LabView 7.0TM. The procedure to control the steady regime in the spouted bed process was: define the dominant frequency as the controlled variable and the signal of command for frequency inverter as the manipulated variable. The dominant frequency was determined by the spectral analysis of pressure fluctuations in the spouted bed. The command signal for frequency inverter affected the air flow variable. Step disturbances were applied in open loop in the manipulated variable to determine the parameters of the controller and control system was implemented in the process. Step disturbances like addition of particles in the spouted bed and change the position of opening of the air valve were applied in closed-loop to test the performance of the controller. The results show that PI controller was able to maintain the system operating in steady regime when disturbances were applied in the feed stream, which was the goal of this research / Mestrado / Engenharia de Processos / Mestre em Engenharia Química

Ingeniero Civil Eléctrico / Una de las principales variables a controlar en un sistema eléctrico es la frecuencia. Para asegurar su estabilidad en las 2 etapas de control (control primario (CPF) y secundario de frecuencia (CSF)) se hace imprescindible un correcto ajuste de las ganancias de los reguladores involucrados. A través de esta memoria se busca proponer una metodología para el ajuste óptimo de reguladores PI encargados del CPF, los cuales pueden ser de frecuencia o potencia-frecuencia. Existe una infinidad de técnicas para definir los parámetros de los reguladores PI, no obstante no todas se ajustan al contexto de regulación de frecuencia utilizando centrales hidráulicas. En esta memoria se estudiaron 2 metodologías: ajuste según Bode y según Ziegler-Nichols. A través de un modelo lineal se aplicaron dichas metodologías al caso particular de la central Colbún. Luego, llevando los mismos ajustes a un modelo no lineal del sistema, se evaluó el desempeño de los reguladores para distintos escenarios y configuraciones: operación en isla y red; distintos niveles de potencia; diferentes niveles de cota de embalse. Para los casos en que la central opera con una cota alta y ésta se encuentra en la sección ancha de la chimenea de equilibrio que posee el sistema, los resultados muestran una respuesta que cumple con las exigencias presentadas en la Norma Técnica. Sin embargo, para cotas inferiores, cuando la cota pasa a la sección angosta de la chimenea, se observan respuestas no acorde a lo exigido. Para ello fue necesario proponer ajustes adicionales. De los resultados se observó que con el reajuste propuesto se cumplen con las exigencias de la Norma Técnica. Luego de establecer una comparación entre las respuestas del modelo no lineal y lineal, se obtuvo que para las condiciones de cota alta es posible utilizar el modelo lineal como una buena aproximación del no lineal. Luego, el análisis realizado para el CSF se realizó utilizando el modelo lineal. Se empleó un modelo de 2 centrales, con 2 generadores en cada una, donde una central se encarga exclusivamente del CPF mientras que la otra se encarga del CSF. Se ajustaron los principales parámetros del regulador encargado del CSF: la constante de tiempo del bloque integral y la tasa de toma de carga de las unidades. A través de las simulaciones se observó que el ajuste cumple con las exigencias fijadas por la Norma Técnica. El Artículo 3-17 de la Norma Técnica propone 2 alternativas para el control secundario de frecuencia: un control centralizado en el CDEC y uno localizado en una central (en este caso Colbún). Utilizando el sistema mencionado en el párrafo anterior, se estudiaron y compararon ambas alternativas. Se observó que la opción de un control localizado en una central es una solución simple, eficiente y viable, mientras que la alternativa de un control centralizado conlleva dificultades como lo son la presencia de oscilaciones sostenidas en el tiempo (ciclos límite), las cuales se deben a la presencia de retardos en el envío y recepción de las señales y a la difcultad de coordinación entre las tomas de carga de las unidades y la fijada por el CDEC.

Esta dissertação, "O Educador e a Assessoria EP/PI de Porto Alegre em cena na prevenção do Autismo", tem como objetivo refletir sobre os laços e as possibilidades constitutivas dos atos educativos de três educadores da escola infantil João Alhures com duas crianças pequenas que apresentavam sinais de Autismo em 2014, a partir do assessoramento denominado Educação Estruturante. A Educação Estruturante é uma concepção de trabalho da Assessoria EP/PI baseada nas leituras dos aspectos do desenvolvimento e da singularidade dos alunos da Educação Infantil, englobando isso aos seus planejamentos educativos. A posteriori, penso que a primeira etapa da pesquisa foi em 1991, quando foram criados os atendimentos de Educação Precoce, Psicopedagogia Inicial e a Assessoria de Inclusão dessas modalidades à Educação Infantil. A segunda etapa foi em 2014, quando foram detectados os sinais de Autismo em duas crianças que frequentavam o berçário da escola infantil João Alhures. Após, a terceira etapa consistiu na realização de uma avaliação psicanalítica das crianças aos seus três anos de idade, a fim de observar se ainda apresentavam sinais de Autismo. Já a quarta etapa consistiu na realização de entrevistas aos educadores, a fim de compreender como e quais laços discursivos estabelecidos entre ambos podem ter contribuído para a não fixação dessa estrutura psíquica. Para tal, a direção desta pesquisa trouxe surpresas ao ler que a Assessoria denominada Educação Estruturante se mostrou como movimentadora dos giros discursivos e do desejo dos educadores ao intervirem e participarem do processo de subjetivação das crianças pequenas com sinais de Autismo. Dessa forma, apostou-se que, na cena lúdica entre educador e crianças da pesquisa – as quais nos pareceram como sendo as prediletas entre as outras –, os educadores se autorizaram a exercer posições discursivas que lembravam as funções de pai, mãe, professores e terapeutas em estimulação precoce. Para tal leitura, a noção de semblante ganhou importância, no sentido de ser a agente nos quatro discursos de Lacan (1969-1970/1992) e a sustentadora do discurso analítico. Nessa direção, associamos que o educador também pode ter suas posições discursivas de semblante, ao realizar ¼ de giro nestas e produzir atos estruturantes que lembrem um pai, uma mãe, uma mestra e as vezes, um terapeuta em EP. As posições discursivas de semblante tomaram um caminho de ato estruturante, ao ser usual, atualmente, o educador passar quase 12 horas com as crianças e passar a ocupar papéis que ampliem o seu campo pedagógico. A partir dessas urgências, o educador foi lançado ao campo da invenção e do brincar denominado estruturante (Jerusalinsky, 1999). Esse brincar, a posteriori, se mostrou como possibilitador na promoção e articulação necessária para a constituição das crianças enquanto sujeitos. Nesse rumo, considerou-se que os educadores, conforme seu desejo pelas crianças e a Assessoria EP/PI recebida, parecem ter realizado o semblante necessário para que o brincar estruturante aparecesse, possibilitando atos de inscrições nelas. Também, demos destaque ao desejo do educador e à sua boa transferência com a Assessoria EP/PI. Enfim, ao final da pesquisa, apresentou-se como relevante os caminhos do semblante e do Entre (Bhabha, 1998), enquanto possibilidade da construção de um lugar transdisciplinar entre o campo da estrutura psíquica indecidida (Bernardino, 2004) e o campo do discurso (Lacan, 1969-1970/1992) para não fixação do Autismo. Afinal, que posições discursivas são essas que os educadores transitam, que não é mãe, não é pai, não é analista e nem terapeuta em EP? / This dissertation, "The Educator and Counseling EP/PI from Porto Alegre in scene on autism’s prevention", aims to consider the bond sand the constitutive possibilities of the pedagogical action sof three teachers from João Alhures school with two small children who have shown signs of autism in 2014, based on the counseling called Structuring Education. Structuring Education is a work concept of the EP/PI Counseling based on the readings of the development aspects and singularity of the students of early education, encompassing this with their educational planning. A posteriori, I believe that the first stage of the research was in 1991, when the services of Early Education, Initial Psychopedagogy and the counceling of Inclusion of these modalities to early childhood education were created. The second stage was in 2014, when signs of autism were detected in two children who attended the nursery school of Juan Alhures. Later on, the third step consisted in performing a psychoanalytic evaluation of children at the age of three, in order to see if they still showed signs of autism. The fourth stage consisted on interviewing the educators in order to understand how and what discursive bonds established between both may have contributed to the non-fixation of this psychic structure. Hence, the focus of this research was a surprise when reading that the counseling denominated Structure Education was shown as a mover of the discursive turns and of the longing of the educators when intervening and participating in the process of subjectivation of small childrenwith signs of autism. Thus, it was bet that in the playful setting between educator and the children of the research, which appeared to us as their favorite among the others, these educators allowed themselves to apply discursive positions that resembled the roles of father, mother, teachers and therapists in EP. For such reading, the notion of countenance has become important in the sense of being the agent in Lacan's four speeches, (1969-1970/1992) and supporter of the analytic discourse. Within this approach, we can relate that the educator can also have his or her own discursive positions of likeness, by performing ¼ of these in turn and producing structuring performances that resemble a father, a mother, a teacher and sometimes a therapist in early stimulation. The discursive positions of likeness took a path of structuring performances, as it is usual nowadays, the educator spends almost 12 hours with the children and ends up performing roles that broad en their pedagogical field. From these demandings, the educator was launched in to the field of invention and play called structuring (Jerusalinsky, 1999). This play, a posteriori, has shown itself as an enabler in the promotion and articulation necessary for the establishment of children as subjects. As follows, it was considered that the educators, according to their motive towards the children and the given counseling, seem to have accomplished the likeness necessary so that the structuring play could appeared, making possible the acts of inscriptions in these. We have highlight ted the educator's motive and its good convey with the EP/PI Counseling. Finally, at the end of the research, the paths of likeness and the "Entre"(Bhabha, 1998) were presented as relevant, as a possible way of constructing a transdisciplinary place between the field of undecided psychic structure (Bernardino, 2004) and the field of discourse (Lacan, 1969-1970/1992) for the non-fixation of Autism. After all, what discursive positions are these ones that the educators are going through, who is not mother, not a mother, not a father, not an analyst, or a therapist in EP?

Buffer tanks are widely used within the process industry to prevent flow variations from being directly propagated throughout a plant. The capacity of the tank is used to smoothly transfer inlet flow upsets to the outlet. Ideally, the tank thus works as a low pass filter where the available tank capacity limits the achievable flow smoothing. For infrequently occurring upsets, where the system has time to reach steady state between flow changes, the averaging level control problem has been extensively studied. After an inlet flow change, flow filtering has traditionally been obtained by letting the tank level deviate from its nominal value while slowly adapting the outlet to cancel out the flow imbalance and eventually bringing back the level to its set-point. The system is then again in steady state and ready to surge the next upset. By ensuring that the single largest upset can be handled without violating the level constraints, satisfactory flow smoothing is obtained. In this thesis, the smoothing of frequently changing inlet flows is addressed. In this case, standard level controllers struggle to obtain acceptable flow smoothing since the system rarely is in steady state and flow upsets can thus not be treated as separate events. To obtain a control law that achieves optimal filtering while directly accounting for future upsets, the averaging level control problem was approached using robust model predictive control (MPC). The robust MPC differs in the way it obtains flow smoothing by not returning the tank level to a fixed set-point. Instead, it lets the steady state tank level depend on the current value of the inlet flow. This insight was then used to propose a linear control structure, designed to filter frequent upsets optimally. Analyses and simulation results indicate that the proposed linear and robust MPC controller obtain flow smoothing comparable to the standard optimal averaging level controllers for infrequent upsets while handling frequent upsets considerably better.

Nous proposons des méthodes simples et efficaces pour manipuler des expressions trigonométriques de la forme $F=\sum_{k} f_k\cos\tfrac{k\pi}{n}, f_k\in Z$ où $d<n$ fixé. Nous utilisons les polynômes unitaires de Chebyshev qui forment une base de $Z[x]$ avec laquelle toutes les opérations arithmétiques peuvent être exécutées aussi rapidement qu'avec la base de monômes, mais également déterminer le signe et une approximation de $F$, calculer le polynôme minimal de $F$. Dans ce cadre nous calculons efficacement le polynôme minimal de $2\cos\frac{\pi}{n}$ et aussi le polynôme cyclotomique $\Phi_n$. Nous appliquons ces méthodes au calcul des diagrammes de nœuds de Chebyshev $C(a,b,c,\varphi) : x=T_a(t), y=T_b(t), z=T_c(t+\varphi)$, ce qui permet de tester si une courbe donnée est un nœud, et aussi lister tous les nœuds de Chebyshev possibles quand un triple $(a,b,c)$ fixé en bonne complexité. / We propose a set of simple and fast algorithms for evaluating and using trigonometric expressions in the form $F=\sum_{k}f_k\cos\frac{k\pi}{n}$, $f_k\in Z$ where $d<n$ fixed. We make use of the monic Chebyshev polynomials as a basis of $Z[x]$. We can perform arithmetic operations (multiplication, division, gcd) on polynomials expressed in a Chebyshev basis (with the same bit-complexity as in the monomial basis), compute the sign of $F$, evaluate it numerically and compute its minimal polynomial in $Q[x]$. We propose simple and efficient algorithms for computing the minimal polynomial of $2\cos\frac{\pi}{n}$ and also the cyclotomic polynomial $\Phi_n$. As an application, we give a method to determine the Chebyshev knot's diagrams $C(a,b,c,\varphi) : x=T_a(t),y=T_b(t), z=T_c(t+\varphi)$ which allows to test if a given curve is a Chebyshev knot, and point out all the possible Chebyshev knots coressponding a fixed triple $(a,b,c)$, all of these computings can be done with a good bit complexity.