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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
981

Reduced Order Modeling with Variable Spatial Fidelity for the Linear and Nonlinear Dynamics of Multi-Bay Structures

January 2017 (has links)
abstract: This investigation develops small-size reduced order models (ROMs) that provide an accurate prediction of the response of only part of a structure, referred to as component-centric ROMs. Four strategies to construct such ROMs are presented, the first two of which are based on the Craig-Bampton Method and start with a set of modes for the component of interest (the β component). The response in the rest of the structure (the α component) induced by these modes is then determined and optimally represented by applying a Proper Orthogonal Decomposition strategy using Singular Value Decomposition. These first two methods are effectively basis reductions techniques of the CB basis. An approach based on the “Global - Local” Method generates the “global” modes by “averaging” the mass property over α and β comp., respectively (to extract a “coarse” model of α and β) and the “local” modes orthogonal to the “global” modes to add back necessary “information” for β. The last approach adopts as basis for the entire structure its linear modes which are dominant in the β component response. Then, the contributions of other modes in this part of the structure are approximated in terms of those of the dominant modes with close natural frequencies and similar mode shapes in the β component. In this manner, the non-dominant modal contributions are “lumped” onto the dominant ones, to reduce the number of modes for a prescribed accuracy. The four approaches are critically assessed on the structural finite element model of a 9-bay panel with the modal lumping-based method leading to the smallest sized ROMs. Therefore, it is extended to the nonlinear geometric situation and first recast as a rotation of the modal basis to achieve unobservable modes. In the linear case, these modes completely disappear from the formulation owing to orthogonality. In the nonlinear case, however, the generalized coordinates of these modes are still present in the nonlinear terms of the observable modes. A closure-type algorithm is then proposed to eliminate the unobserved generalized coordinates. This approach, its accuracy and computational savings, was demonstrated on a simple beam model and the 9-bay panel model. / Dissertation/Thesis / Doctoral Dissertation Mechanical Engineering 2017
982

Measuring Digital Advertising Effectiveness: Solving the Count/Quality Dilemma

January 2017 (has links)
abstract: Total digital media advertising spending of $72.5 billion surpassed total television Ad spending of $71.3 billion for the first time ever in 2016. Approximately $39 billion, or 54% of the digital media advertising spend, involved pre-programmed software that purchased Ads on behalf of a buyer in Real-Time Bidding (RTB) settings. A major concern for Ad buyers is sub-optimal spending in RTB settings owing to biases in the attribution of customer conversions to Ad impressions. The purpose of this research is twofold. First, identify and propose a novel experimental design and analysis plan for to handling a previously unidentified and unaddressed source of endogeneity: count/quality simultaneity bias (CQB). Second, conduct a field study using data for Ad response rates, cost, and observed consumer behavior to solve for the profit maximizing daily Ad frequency per customer. One large online retailer provided data for Ad impressions, bid costs, response rates, revenue per visit, and operating costs for 153,561 unique users over 23 days. Unique visitors were randomly assigned to one of seven treatment groups with one, two, three, four, five, and six impressions per day limits as well as a final condition with no daily impression cap. Ordinary least square models (OLS) were fit to the data and a non-linear relationship between Ad impressions and site visits demonstrating declining marginal effect of Ad impression on site visits after an optimal point. The results of the field study confirmed the existence of negative CQB and demonstrated how my novel experimental design and analysis can reduce the negative bias in the estimate of impression quantity on customer response. Second, managers interested in improving the efficiency of advertising spend should restrict display advertising to only the highest quality inventory through specific site targeting and by leveraging direct buys and private marketplace deals. This strategy ensures that subsequent impressions are not of lower quality by restricting the pool of possible impressions from a homogenous set of high quality inventory. / Dissertation/Thesis / Doctoral Dissertation Business Administration 2017
983

An Exploration of Statistical Modelling Methods on Simulation Data Case Study: Biomechanical Predator–Prey Simulations

January 2018 (has links)
abstract: Modern, advanced statistical tools from data mining and machine learning have become commonplace in molecular biology in large part because of the “big data” demands of various kinds of “-omics” (e.g., genomics, transcriptomics, metabolomics, etc.). However, in other fields of biology where empirical data sets are conventionally smaller, more traditional statistical methods of inference are still very effective and widely used. Nevertheless, with the decrease in cost of high-performance computing, these fields are starting to employ simulation models to generate insights into questions that have been elusive in the laboratory and field. Although these computational models allow for exquisite control over large numbers of parameters, they also generate data at a qualitatively different scale than most experts in these fields are accustomed to. Thus, more sophisticated methods from big-data statistics have an opportunity to better facilitate the often-forgotten area of bioinformatics that might be called “in-silicomics”. As a case study, this thesis develops methods for the analysis of large amounts of data generated from a simulated ecosystem designed to understand how mammalian biomechanics interact with environmental complexity to modulate the outcomes of predator–prey interactions. These simulations investigate how other biomechanical parameters relating to the agility of animals in predator–prey pairs are better predictors of pursuit outcomes. Traditional modelling techniques such as forward, backward, and stepwise variable selection are initially used to study these data, but the number of parameters and potentially relevant interaction effects render these methods impractical. Consequently, new modelling techniques such as LASSO regularization are used and compared to the traditional techniques in terms of accuracy and computational complexity. Finally, the splitting rules and instances in the leaves of classification trees provide the basis for future simulation with an economical number of additional runs. In general, this thesis shows the increased utility of these sophisticated statistical techniques with simulated ecological data compared to the approaches traditionally used in these fields. These techniques combined with methods from industrial Design of Experiments will help ecologists extract novel insights from simulations that combine habitat complexity, population structure, and biomechanics. / Dissertation/Thesis / Masters Thesis Industrial Engineering 2018
984

The Design and Characterization of a Soft Haptic Interface for Rehabilitation of Impaired Hand Function

January 2018 (has links)
abstract: The human hand comprises complex sensorimotor functions that can be impaired by neurological diseases and traumatic injuries. Effective rehabilitation can bring the impaired hand back to a functional state because of the plasticity of the central nervous system to relearn and remodel the lost synapses in the brain. Current rehabilitation therapies focus on strengthening motor skills, such as grasping, employ multiple objects of varying stiffness and devices that are bulky, costly, and have limited range of stiffness due to the rigid mechanisms employed in their variable stiffness actuators. This research project presents a portable cost-effective soft robotic haptic device with a broad stiffness range that is adjustable and can be utilized in both clinical and home settings. The device eliminates the need for multiple objects by employing a pneumatic soft structure made with highly compliant materials that act as the actuator as well as the structure of the haptic interface. It is made with interchangeable soft elastomeric sleeves that can be customized to include materials of varying stiffness to increase or decrease the stiffness range. The device is fabricated using existing 3D printing technologies, and polymer molding and casting techniques, thus keeping the cost low and throughput high. The haptic interface is linked to either an open-loop system that allows for an increased pressure during usage or closed-loop system that provides pressure regulation in accordance with the stiffness the user specifies. A preliminary evaluation is performed to characterize the effective controllable region of variance in stiffness. Results indicate that the region of controllable stiffness was in the center of the device, where the stiffness appeared to plateau with each increase in pressure. The two control systems are tested to derive relationships between internal pressure, grasping force exertion on the surface, and displacement using multiple probing points on the haptic device. Additional quantitative evaluation is performed with study participants and juxtaposed to a qualitative analysis to ensure adequate perception in compliance variance. Finally, a qualitative evaluation showed that greater than 60% of the trials resulted in the correct perception of stiffness in the haptic device. / Dissertation/Thesis / Masters Thesis Biomedical Engineering 2018
985

Hybrid orthogonal code sequences for high-density synchronous CDMA systems

Pramaita, Nyoman January 2014 (has links)
One of the primary tasks of the mobile system designers in order to support high density of devices in a CDMA system is to create a code sequence with a capacity for large number of spreading code sequences having low cross-correlation values between them, in order to ensure accommodation of large number of users and to minimise the effect of multiple access interference. In this research, the design for a novel hybrid orthogonal very large set (HOVLS) code sequence is proposed for high density mobile application scenarios. The design and development of both fixed and variable spreading factor code sequences are presented in this thesis. Both type of code sequences have been implemented via simulation using Matlab/Simulink. The performance of the code sequences has been evaluated and compared with that of existing code sequences. The proposed code sequences are more advantageous for high density mobile networks. The unique feature of the fixed length HOVLS code sequence is that its ACF, CCF, and BER performances are similar to that of orthogonal Gold code sequence and orthogonal m-sequence under Rayleigh flat and frequency selective fading channel conditions while having a significantly higher capacity than those orthogonal code sequences. The proposed HOVLS code sequence could support 134 different cells which is more than twice than that of orthogonal Gold code sequence and orthogonal m-sequence. To the knowledge of the author, this is the largest reported family size in the literature for an orthogonal code sequence for CDMA applications. In order to support variable data rate, fixed length HOVLS code sequence was developed into orthogonal variable spreading factor code sequence. It is shown that the proposed OVSF code sequence has slightly better CCF than those of OVSF Gold code sequence and m-sequence in terms of CM (correlation margin). The ACF of the proposed OVSF code sequence is similar to those of OVSF Gold code sequence and m-sequence. The proposed OVSF code sequence possesses comparable BER performance to those of orthogonal Gold code sequence and orthogonal m-sequence under flat fading channel condition. Whereas, the BER performance of the proposed OVSF code sequence is slightly better than that of Gold code sequence and OVSF m-sequence under frequency selective fading channel. Therefore, the proposed HOVLS code sequence is appropriate code sequence in CDMA systems than those of orthogonal Gold code sequence and orthogonal m-sequence for both fixed and variable rate high density network applications.
986

Tidsförskjutningar av flyttfåglars höstmigration och vistelse i häckningsområdet : betydelsen av att kunna variera kullantalet i ett varmare klimat / Time Shifts of Birds´ Autumn migration and Lenght of Stay in the Breeding Area : The significance of being able to vary the number of broods in a warming climate

Lotsander, Anna January 2018 (has links)
The timing of many biological events, including the onset of spring and bird migration, have changed in the recent years due to climate change. This may affect birds’ length of stay in the breeding area. By using Swedish ringing data from two periods, 1979-1989 and 2006-2016, changes in the length of stay between birds with different migration modes and seasonal number of broods were analysed. The results indicated that changes in the length of stay differed between species depending on their seasonal number of broods. Species with a fixed number of broods shifted their stay by arriving earlier in the spring and migrating earlier in the fall. In contrast, species with a variable number of broods extended their stay by arriving earlier in the spring without changing the timing of autumn migration. An extended stay might enable a higher reproduction output by giving the opportunity to invest more time in offspring. Thus, climate change might favour species with a variable number of broods. Birds with a fixed number of broods might however not experience the same benefits of a warmer climate because their annual reproductive success often relies on one single brood. Species with a fixed number of broods are generally long-distance migrants and therefore their migration is less flexible. If they do not arrive early enough to match their breeding with the advanced timing of peak food abundance a mismatch arises. As a result, they might be more sensitive to climate change
987

Métodos de custeio e o custeio alvo: uma contribuição ao estudo de custos em organizações hospitalares / Cost methods and target costing: A contribution to hospitals costs study

Edison de Lima Júnior 20 April 2006 (has links)
Nas últimas décadas, a humanidade presenciou um grande avanço tecnológico, disponibilizando um aumento expressivo de informações aos gestores empresariais. Por isso, as organizações são impelidas a revisar suas práticas gerenciais que possibilitem sua participação no mercado a cada dia mais competitivo. Esse quadro não é diferente nas organizações hospitalares. O aproveitamento eficiente de seus recursos assume uma importância maior pelo interesse social que os hospitais desempenham em nossa sociedade. Nesse sentido, os custos dos serviços hospitalares merecem destaque, pois eles estão entre os elementos de maior importância para a análise gerencial dessas instituições. Nesse contexto, o Custeio Alvo aparece como uma importante ferramenta de auxílio aos administradores hospitalares no gerenciamento dos custos. Essa ferramenta é aplicável a qualquer organização, mas apresenta resultados mais satisfatórios, quando aplicada em ambientes em que há pressão de preços e de custos. Entretanto, poucos estudos dedicam-se a sua aplicação no setor de serviços. Nesse sentido, este trabalho dedica-se a investigação dos métodos de custeio utilizados no gerenciamento de custos em hospitais na ótica da filosofia do Custeio Alvo. O objetivo é identificar o método de custeio que proporciona mais benefícios ao gerenciamento de seus custos. No entanto, o estudo resume-se a dois métodos: o Custeio Variável e o Custeio Baseado em Atividades. A pesquisa utiliza a metodologia do estudo de caso apoiado em uma unidade hospitalar de pequeno porte, mas de alta complexidade. Utiliza também, em entrevistas semi-estruturadas com os principais administradores para identificar as características do modelo de gestão do hospital, verificar a aderência dessas características a filosofia do Custeio Alvo e identificar as variáveis dos métodos de custeio adotadas pelo hospital. Ao final, a pesquisa conclui que o modelo de gestão do hospital atende aos princípios do Custeio Alvo e que o método que mais benefícios proporciona ao gerenciamento de seus custos, considerando os princípios do Custeio Alvo, é o método do Custeio Variável. / Lately, the humankind has experienced a huge technological advance, which resulted in an expressive rising of information for managers. Consequently, it is not possible for the organizations to revise their management practices responsible for their participation in the competitive market. Such a fact does not change in hospitals. The efficient profit of their resources receives major importance by the social interest those hospitals perform in our society. This way, it is vital to highlight the cost of hospital services, as they are among the most crucial elements for their management analysis. So, the Target Costing comes as an important tool to help hospital managers administrate costs. Such a tool can be applied to any organization. Nevertheless, if applied when there is price and costs pressure, its results can be more satisfying. Therefore, there are not many researches concerning its application in the service sector. Because of that, this piece of work aims at investigating the cost methods that can be used to manage costs in hospitals, based on the Target Costing. In addition, to identify the cost method that generates more benefits to cost management. However, only two methods will be focused: the Variable Costing and the Cost Based on Activities. For this, it was used the methodology of the study of case, regarding a small but complex hospital structure. It is also used in semi-structured interviews with the main managers to identify the characteristics of the hospital management model, to verify if those characteristics adhere to the Target Costing and to identify the variables of the cost methods adopted by the hospital. In the end, it was concluded that the hospital management model attends the Target Costing principles. Furthermore, the Variable Costing is the method that generates more benefits of its costs, when considering the Target Costing.
988

Desenvolvimento e análise de um protótipo automatizado para dosagem pontual de fertilizantes sólidos em taxas variáveis

Di Raimo, Conrado [UNESP] 24 March 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-03-24Bitstream added on 2014-06-13T20:37:36Z : No. of bitstreams: 1 diraimo_c_me_bauru.pdf: 1842866 bytes, checksum: 36d05c62d9c28fd1f941cb059f62bf3d (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A crescente demanda por alimentos no mundo, com a mesma área agrícola e com os recursos financeiros para a aquisição de fertilizantes, cada vez mais escassos é inevitável à utilização de novas tecnologias para fazer frente a essa nova realidade, pois com o uso dessas pode-se produzir mais alimentos com menos fertilizantes. Na busca por novas tecnologias que fazem o processo produtivo mais eficiente é que surge a chamada Agricultura de Precisão utilizada como uma alternativa para aperfeiçoar o processo de produção agrícola. As ações que conduzem à chamada agricultura de precisão exigem diversas etapas para sua implementação. Contudo, uma das mais importantes está relacionada com o tratamento localizado das culturas, para isto, tem-se a necessidade de desenvolver equipamentos capazes de executar tais tarefas. Com esse intuito estudou-se o comportamento de um protótipo que tem como objetivo dosar e aplicar no momento do plantio, três fertilizantes sólidos simultâneos, que são: Nitrogênio, Fósforo e Potássio (N, P e K) em taxas variáveis de acordo com as quantidades desejáveis da cultura em questão. Para a avaliação do protótipo foi construída uma bancada de testes onde foram acoplados os dosadores helicoidais e seus respectivos motores elétricos de corrente contínua e três tanques para armazenamento de fertilizantes. Também foram utilizados equipamentos complementares tais como: uma fonte (12vdc); três drivers de potência (MOSFET); um Desktop; uma placa de aquisição e controle e um software de Instrumentação Virtual. Os ensaios foram realizados com o software de instrumentação e controle virtual (LabVIEW®), que teve como função, controlar a rotação dos eixos dos três motores de maneira independente, baseando-se em dados de um mapa de fertilidade do solo com localização fundamentada em informações geográficas, obtendo a vazão... / The increasing demand for food in the world with the same agricultural area and the financial resources to purchase fertilizes, more and more scarse it is inevitable to use new technologies to confront this new reality, because with the use of these can produce more food with less fertilizer. In the search for new tecnologies that make the production process more efficient arises the called precision agriculture used as an alternative to improve the agricultural production process. The action that lead to the called precision agriculture require several steps for its implementation. However, one of the most important is related to the localized treatment of cultures, for this, there is the need to develop equipment capable of performing such tasks. With this aim we studied the behavior of a prototype which aims to meter and apply at the planning moment three simultaneous solid fertilizers, which are: nitrogen, phosphorus and potassium (N, P and K) with variable rates according with the desired quantities of the culture in question. For the evaluation of the prototype was built a test bench where engaged the helical dosers and their respective direct current electric motors and three tanks for storage of fertilizers. Were also used additional equipment such as: a source (12vdc), threee power drivers (MOSFET), a desktop, an acquisition board and control software and virtual instrumentation. The test were performed with the software virtual instrumentation and control (LabVIEW®), with had as its objective to control the rotation of the axes of the three engines independently, based on data from a map of soil fertility based on location information geographical, obtaining the mass flow of the desired product in the exact location and quatity needed for the plant, according to the size of grid soil sampling. The values of the mass flow rate determined by the time were compared with... (Complete abstract click electronic access below)
989

Reconfiguração de sistemas de distribuição de energia elétrica utilizando a metaheurística busca em vizinhança variável

Zvietcovich, Wilingthon Guerra [UNESP] 25 August 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:22:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-08-25Bitstream added on 2014-06-13T20:27:15Z : No. of bitstreams: 1 zviecovich_wg_me_ilha.pdf: 671253 bytes, checksum: fa917bf3d6aa15db73057717470be218 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Ensino Pesquisa e Extensão de Ilha Solteira (FEPISA) / A reconfiguração de sistemas de distribuição de energia elétrica consiste em alterar a topologia das redes através da abertura/fechamento das chaves de interconexão. Normalmente este procedimento é feito para fins de isolamento de faltas, minimização de perdas ativas, balanceamento de cargas entre alimentadores ou para melhoria dos níveis de tensão. Atingir estes objetivos é difícil, devido ao grande número de variáveis envolvidas e das restrições impostas, sendo a radialidade uma restrição de difícil representação matemática. Este problema pode ser classificado dentro dos problemas de programação não linear inteiro misto (PNLIM) e apresenta o fenômeno da explosão combinatória. Neste trabalho tem-se como principal objetivo o desenvolvimento de uma metaheurística chamada Busca em Vizinhança Variável para a reconfiguração de sistemas de distribuição de energia elétrica com respostas no planejamento da operação em função da razonalidade da carga. Verificamos que este método mostrou ser eficiente, pois através de uma metodologia simples, obteve-se resultados melhores em relação aos apresentados na literatura. / The network reconfiguration of electric power distribution consists of changing the topology of networks through the opening/closing of interconnection switches. This pro- cedure is usually done to isolate faught, reduction real power losses, balance the load among feeders or for improvement of tension levels. To reach these objectives is diffi- cult, due to the great number of involved variables and the imposed constraints, being the constraint of radial structure of difficult mathematical representation. This problem can be classified as nonlinar mixed integer programming problems and it presents the phenomenon of combinatorial explosion. The main objective og this work is to develop a metaheuristic called Variable Neighbourhood Search for network reconfiguration of elec- tric power distribution for operation planning based on rationality of load. This method showed to be efficient using a simple methodology, getting better results in relation to the presented in Literature.
990

Propriedades eletrônicas da matéria topológica: heteroestruturas e efeitos da rotação

Lima, Jonas Romero Fonseca de 19 February 2014 (has links)
Made available in DSpace on 2015-05-14T12:14:10Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1315751 bytes, checksum: ac1c804a66de6eb3a5e3c4a1cb7d3e04 (MD5) Previous issue date: 2014-02-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this thesis we study the electronic properties of several systems of condensed matter physics using two different continuum models, the effective mass theory and the effective Dirac Hamiltonian. In several systems, there is an effective mass depending on position. Some models for the kinetic energy operator were proposed to describe these systems, but there is no definition of which one is the most appropriate. It is one of the oldest open questions in solid state physics. We propose a new model, where we consider all permutations among the operators and show that it satisfies the fundamental requirements of quantum mechanics. We use this model to obtain the minibands structure of a heterostructure composed by two different materials and compare our model with other models previously proposed. We also get the Schrödinger equation for a particle constrained to a curved surface with position dependent mass. We follow the da Costa approach, where there is a geometric potential. We show that the position dependent mass does not affect the geometric potential, contributing only to the kinetic part. We use this equation to study the electronic transport in a junction of two cylinders with different radii, with the effective mass varying with the cylinder radius. Using the effective Dirac Hamiltonian, we consider a graphene sheet on a periodic substrate heterostructure composed by two different materials. Each material induces a specific energy gap and Fermi velocity in the graphene, so the Dirac Hamiltonian has a gap (mass) term and a Fermi velocity depending on position. We write this operator taking into account that it has to be Hermitian and we obtain the minigaps induced by the substrate in the electronic structure of graphene. Motivated by experimental results, we study the effects of rotation on the electronic structure of carbon nanotubes, fullerene C60 and topological insulators, using an effective Dirac operator. In the carbon nanotube and C60 cases, the rotation adds a shift in the energy levels and a break in spin degeneracy. In the topological insulator case, the rotation adds only a shift in the energy. / Nesta tese estudamos as propriedades eletrônicas de diversos sistemas físicos da matéria condensada utilizando dois modelos contínuos distintos, o modelo de massa efetiva e o hamiltoniano de Dirac efetivo. Em vários sistemas existe o aparecimento de uma massa efetiva dependente da posição. Diversos modelos para o hamiltoniano cinético com massa efetiva variável foram propostos, mas não existe uma definição de qual seja o mais adequado. Essa é uma das questões mais antigas em aberto na física do estado sólido. Nós propomos um novo modelo, levando em conta todas as permutações possíveis entre os operadores e mostramos que ele satisfaz os requisitos fundamentais da mecânica quântica. Nós usamos esse modelo para obter a estrutura de minibandas de uma heteroestrutura formada por dois materiais diferentes e comparamos o nosso modelo com outros modelos propostos anteriormente. Também obtemos a equação de Schrödinger para uma partícula confinada a uma superfície curva com massa efetiva dependendo da posição. Seguimos a abordagem de da Costa, onde surge um potencial geométrico. Mostramos que a massa variável não altera a potencial geométrico, contribuindo apenas para a parte cinética. Nós usamos a equação obtida para estudar as propriedades de transporte eletrônico em uma junção de dois cilindros de raios diferentes, com a massa efetiva variando com o raio do cilindro. Utilizando um hamiltoniano de Dirac efetivo nós consideramos o grafeno sobre um substrato formado por uma heteroestrutura com dois materiais diferentes. Cada material induz um gap de energia e uma velocidade de Fermi específica no grafeno, fazendo com que tenhamos um hamiltoniano de Dirac com termo de gap (massa) e velocidade de Fermi dependendo da posição. Nós escrevemos esse operador levando em conta que ele tem que ser hermitiano e obtemos a estrutura de minibandas induzidas na estrutura eletrônica do grafeno pelo substrato. Motivados por resultados experimentais, nós também estudamos os efeitos da rotação na estrutura eletrônica do nanotubo de carbono, fulereno C60 e isolante topológico, utilizando um hamiltoniano de Dirac efetivo. Para o nanotubo de carbono e o C60 a rotação adiciona um deslocamento nos níveis de energia e há uma quebra na degenerescência de spin. No isolante topológico a rotação induz apenas um deslocamento na energia.

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