Thesis (Ph. D.)--University of Chicago, Dept. of Sociology, March 2001. / Includes bibliographical references. Also available on the Internet.

Thesis (Ph.D.)--Mississippi State University. Department of Instructional Systems, Leadership and Workforce Development. / Title from title screen. Includes bibliographical references.

Avec la multiplication des terminaux mobiles et le foisonnement des objets dits « connectés », on assiste à la montée d'un besoin de moyens de communication à tout endroit et en toute situation, accompagné d'un encombrement spectral toujours plus important. Dans ce contexte, si la capacité d'adaptation au canal des modulations multiporteuses permet de bien s'accommoder du besoin de communication en tout endroit, les techniques actuelles, en particulier l'OFDM, souffrent d'une mauvaise localisation fréquentielle et d'un mauvais facteur de crête, ce qui limite leur utilisation dans un contexte embarqué et/ou en présence de fortes contraintes spectrales. Dans cette thèse, nous étudions les modulations multiporteuses au-delà de la cadence de Nyquist. En augmentant la densité de signalisation, ces dernières permettent d'augmenter l'efficacité spectrale. Cela est cependant contrebalancé par l'apparition d'auto-interférence, ce qui rend la réception plus délicate.Sur canal à bruit additif blanc gaussien, on montre comment choisir des impulsions de mise en forme maximisant le rapport signal à interférence plus bruit. On montre que ces dernières permettent d'obtenir une turbo-égalisation linéaire de l'auto-interférence minimisant l'erreur quadratique moyenne. Nos travaux mettent en évidence que ces mêmes impulsions permettent également de réduire le facteur de crête à mesure que la densité augmente. Enfin, sur canal sélectif en fréquence, on vérifie que l'approximation du canal par un coefficient par sous-porteuse est toujours possible. Ces résultats montrent que ce nouveau type de modulation permet d'augmenter l'efficacité spectrale tout en conservant la capacité d'adaptation au canal intrinsèque aux modulations multiporteuses. / With an increasing number of mobile terminals coupled with a large spreading of so-called "smart devices", we can see a growing demand for effective communication means in any place and in any situation.This goes with a more and more overcrowded spectrum.In this context, multicarrier modulations are good candidates to allow effective communication in any place.However current techniques, OFDM in particular, suffer from a bad time--frequency localization and peak-to-average power ratio, limiting their relevancy in an embedded context, or in scenarios with severe spectral constraints.In this thesis, we study faster-than-Nyquist multicarrier modulations.This kind of modulation allow for an increase in spectral efficiency by means of an increase in signaling density.This, in compensation, comes at the price of unavoidable self-interference, which makes demodulation harder.On an additive white Gaussian noise channel, we show how to carefully chose pulse-shapes that maximize signal-to-interference-plus-noise ratio.We show that these particular pulse-shapes yields a linear turbo-equalization of self-interference minimizing the mean squared error.Next, our work highlights the capability of these optimal pulse-shapes to reduce peak-to-average power ratio as density rises.Lastly, on frequency selective channels, we confirm that low complexity equalization using one tap by subcarrier is still possible.These results show how this new modulation technique helps increasing spectral efficiency while keeping what made multicarrier modulations popular: good adaptation to transmission channels.

The purpose of the present study was to explore the implementation of the inclusive education policy in sport in four secondary schools in Masvingo District, Zimbabwe. The case study research design was employed; interviews, focus groups, document analysis and observations were used to collect data. Four school Heads, 4 sports masters, 4 team trainers, 4 team captains, 2 learners with disabilities and a district education officer were purposively selected to take part in this study. Data were presented, analysed/discussed, starting with demographic data in the first section followed by emerging themes. It emerged from the study that all the participants were not knowledgeable about inclusive education and the aspect of including learners with disabilities in mainstream sport. The major barriers identified include inadequate policy dialogue, unavailability of sporting equipment and attitudes. Further findings revealed that there is dire need for knowledge and skills in inclusive sport among teachers in regular schools. Findings also confirmed unavailability of policy circulars in schools. Most teachers were not afforded opportunities to attend workshops and seminars. Findings also revealed that teachers faced major challenges such as funding to undertake courses in SNE and inclusive sport. Teachers were reeled in with a lot of pressure due to congested timetables and large classes. Participants believed that the challenges they faced could be resolved through some proposed intervention strategies. The researcher concluded that teachers in regular schools were not equipped to teach sport to learners with special education needs in the mainstream. The MoPSE was not doing much in preparing teachers to be effective in including learners with disabilities in regular school sport. The study recommended that the MoPSE should put in place provisions to meet the inclusive needs of both teachers and learners. It also recommended that school Heads should be taught about SNE and inclusive sport for them to be able to guide teachers properly. Besides the national policy, schools should design inclusive policies specifically for their respective schools in line with the national policy. The study also recommended that the MoPSE should come up with a comprehensive framework in sport to counter some of these challenges.

The purpose of the present study was to explore the implementation of the inclusive education policy in sport in four secondary schools in Masvingo District, Zimbabwe. The case study research design was employed; interviews, focus groups, document analysis and observations were used to collect data. Four school Heads, 4 sports masters, 4 team trainers, 4 team captains, 2 learners with disabilities and a district education officer were purposively selected to take part in this study. Data were presented, analysed/discussed, starting with demographic data in the first section followed by emerging themes. It emerged from the study that all the participants were not knowledgeable about inclusive education and the aspect of including learners with disabilities in mainstream sport. The major barriers identified include inadequate policy dialogue, unavailability of sporting equipment and attitudes. Further findings revealed that there is dire need for knowledge and skills in inclusive sport among teachers in regular schools. Findings also confirmed unavailability of policy circulars in schools. Most teachers were not afforded opportunities to attend workshops and seminars. Findings also revealed that teachers faced major challenges such as funding to undertake courses in SNE and inclusive sport. Teachers were reeled in with a lot of pressure due to congested timetables and large classes. Participants believed that the challenges they faced could be resolved through some proposed intervention strategies. The researcher concluded that teachers in regular schools were not equipped to teach sport to learners with special education needs in the mainstream. The MoPSE was not doing much in preparing teachers to be effective in including learners with disabilities in regular school sport. The study recommended that the MoPSE should put in place provisions to meet the inclusive needs of both teachers and learners. It also recommended that school Heads should be taught about SNE and inclusive sport for them to be able to guide teachers properly. Besides the national policy, schools should design inclusive policies specifically for their respective schools in line with the national policy. The study also recommended that the MoPSE should come up with a comprehensive framework in sport to counter some of these challenges.

L'augmentation de l'efficacité spectrale des transmissions mono-porteuses sur un lien de diffusion par satellite est devenu un défi d'envergure afin de pallier la demande croissante en débits de transmission. Si des techniques émergentes de transmissions encouragent l'utilisation de modulations à ordre élevé telles que les modulations de phase et d'amplitude (APSK), certaines dégradations sont encourues lors du traitement à bord du satellite. En effet, en raison de l'utilisation d'amplificateurs de puissance ainsi que de filtres à mémoires, les modulations d'ordre élevé subissent des distorsions non-linéaires dues à la fluctuation de leur enveloppe, ce qui nécessite des traitements au sein de l'émetteur ou bien au sein du récepteur. Dans cette thèse, nous nous intéressons au traitement de l'interférence non-linéaire au sein du récepteur, avec une attention particulière aux égaliseurs itératifs qui améliorent les performances du système au prix d'une complexité élevée. A partir du modèle temporel des interférences non-linéaires induites par l'amplificateur de puissance, des algorithmes de réception optimaux et sous optimaux sont dérivés, et leurs performances comparées. Des égaliseurs à complexité réduite sont aussi étudiés dans le but d'atteindre un compromis performances-complexité satisfaisant. Ensuite, un modèle des non-linéarités est dérivé dans le domaine fréquentiel, et les égaliseurs correspondants sont présentés. Dans un second temps, nous analysons et dérivons des récepteurs itératifs pour l'interférence entre symboles non linéaire. L'objectif est d'optimiser les polynômes de distributions d'un code externe basé sur les codes de contrôle de parité à faible densité (LDPC) afin de coller au mieux à la sortie de l'égaliseur. Le récepteur ainsi optimisé atteint de meilleures performances comparé à un récepteur non optimisé pour le canal non-linéaire. Finalement, nous nous intéressons à une classe spécifique de techniques de transmissions mono-porteuse basée sur le multiplexage par division de fréquence (SC-OFDM) pour les liens satellites. L'avantage de ces formes d'ondes réside dans l'efficacité de leur égaliseur dans le domaine fréquentiel. Des formules analytiques de la densité spectrale de puissance et du rapport signal sur bruit et interférence sont dérivées et utilisées afin de prédire les performances du système. / Increasing both the data rate and power efficiency of single carrier transmissions over broadcast satellite links has become a challenging issue to comply with the urging demand of higher transmission rates. If emerging transmission techniques encourage the use of high order modulations such as Amplitude and Phase Shift Keying (APSK) and Quadrature Amplitude Modulation (QAM), some channel impairments arise due to onboard satellite processing. Indeed, due to satellite transponder Power Amplifiers (PA) as well as transmission filters, high order modulations incur non linear distortions due to their high envelope fluctuations which require specific processing either at the transmitter or at the receiver. In this thesis, we investigate on non linear interference mitigation at the receiver with a special focus on iterative equalizers which dramatically enhance the performance at the cost of additional complexity. Based on the time domain model of the non linear interference induced by the PA, optimal and sub-optimal receiving algorithms are proposed and their performance compared. Low complexity implementations are also investigated for the sake of a better complexity-performance trade-off. Then, a non linear frequency domain model is derived and the corresponding frequency equalizers are investigated. In the second part, we analyse and design an iterative receiver for the non linear Inter Symbol Interference (ISI) channel. The objective is to optimize an outer Low Density Parity Check (LDPC) code distribution polynomials so as to best fit the inner equalizer Extrinsic information. The optimized receiver is shown to achieve better performance compared to a code only optimized for linear ISI channel. Finally, we investigate on a specific class of single carrier transmissions relying on Single Carrier Orthogonal Frequency Division Multiplexing (SCO-FDM) for satellite downlink. The advantage of such waveforms lies in their practical receiver implementation in the frequency domain. General analytical formulas of the power spectral density and signal to noise and interference ratio are derived and used to predict the bit error rate for frequency selective multiplexers.

Dans cette thèse, de nouvelles techniques d'égalisation et de précodage pour des systèmes multiporteuses ont été proposées et analysées. D'abord, la performance d'erreur des systèmes multiporteuses à base de bancs de filtres (FBMC) précodées a été analysée. Il a été découvert que cette performance est très sensible à l'égalisation complète des sous-canaux. Quand il y a de l'interference inter-symbole residuel qui vient de l'égalisation imparfaite du sous-canaux, il y a une perte de diversité; cette diversité peut être recuperée avec l'adoption d'un nombre de sous-canaux assez grand pour que chaque sous-canaux subisse de l'évanouissement plat ou avec l'utilisation d'un égaliseur de sous-canaux avec une longueur assez suffisante pour compenser cette réponse en fréquence. Après, une approximation pour la distribution du rapport signal/bruit-plus-interfèrence (SINR) des systèmes SC-FDE qui utilisent égalisation MMSE linéaire a été proposée. Cette approximation utilise la distribution lognormal avec la plus petit distance de Kullback-Leibler vers la vraie distribution, et il s'est révélé qu'elle est precise dans la performance d'erreur; elle sert aussi comme une abstraction de cette système. Avec cette abstraction, une méthode précise pour obtenir la performance d'erreur analytique codée de ces systèmes a été proposée. Finalement, des précodeurs Tomlinson-Harashima (THP) et égaliseurs (linéaires et à retour de décision) largement linéaires pour des systèmes SC-FDE ont été proposés. Ces précodeurs et égaliseurs ont une performance d'erreur mieux quand comparés avec ses versions strictement linéaires si des signaux de constellations impropres sont transmises. Aussi, la performance d'erreur quand des égaliseurs à retour de décision sont utilisés est moins sensible au longueur du filtre de retour. Quand des précodeurs largement linéaires sont utilisés, cette performance devient moins sensible à des erreurs d'estimation du canaux. / In this thesis, new precoding and equalization techniques for multicarrier systems were proposed and analyzed.First, the error performance of precoded filterbank multicarrier (FBMC) systems was analyzed. It was found out that this performance is highly sensitive to complete subchannel equalization. When there is residual intersymbol interference (ISI) stemming from imperfect subchannel equalization there is a loss of diversity; this loss can be prevented with the adoption of a number of subchannels large enough so that each subchannel suffers flat fading or with the utilization of a subchannel equalizer with sufficient length to compensate the subchannel frequency response.After that, an approximation for the signal to interference-plus-noise ratio (SINR) distribution of SC-FDE systems using linear MMSE equalization was proposed. This approximation uses the lognormal distribution with the smallest Kullback-Leibler distance to the true distribution, and was shown to be precise in the error performance sense; it serves as a system abstraction. With this abstraction, a precise method to obtain the analytical coded error performance of these systems was proposed.Finally, widely linear Tomlinson-Harashima precoders and equalizers (linear and decision-feedback) for SC-FDE systems were proposed. These precoders and equalizers have better error performance when compared to their strictly linear versions if signals coming from an improper constellation are transmitted. Their error performance when decision-feedback equalizers are used is less sensitive to the length of the feedback filter. When widely linear precoders are used, this error performance becomes less sensitive to channel estimation errors.

Esta é uma pesquisa qualitativa, de análise documental, cujo objeto de estudo é a legislação vigente sobre acessibilidade em três países da América Latina: Brasil, Bolívia e México, no período entre 1990 e 2005. Os objetivos deste estudo são analisar a legislação de acessibilidade nos países citados e comparar seus conteúdos, verificando quais as relações entre as mesmas e as recomendações internacionais relacionadas ao tema neste período. Os documentos foram abordados a partir de três categorias, desenvolvidas para este estudo: acessibilidade física / arquitetônica; ajudas técnicas para a educação escolar e Cultura de acessibilidade. As indagações que nortearam este estudo buscaram identificar: as especificidades dos direitos da pessoa com deficiência na educação escolar (MAZZOTA, 2006; ROMITA, 2007; GARCIA, 2004; ODEH, 2000; STAINBACK & STAINBACK 1999; AINSCOW, 2001; SASSAKI, 2004; FÁVERO, 2004; SOUSA & PRIETO, 1999; PRIETO, 2003), o papel das recomendações internacionais referentes à pessoa com deficiência no processo de elaboração de garantias legais (IDRM, 2004; CEPAL, 2003) e os desdobramentos do termo acessibilidade como fator de equiparação de oportunidades na educação escolar da pessoa com deficiência (NUNES & SOBRINHO, 2007; OLIVER, 1990; CONVINGTON & HANNAH, 1997; SCIS,2006; LENT, 2005; HOGETOP & SANTAROSA, 2001; NASAA, 2005; TESSARO, 2004; MOYSÉS, 2001; MANZINI, 2006; GRANDJEAN, 1998; AMARAL & NOGUEIRA, 2006; MARTINS NETO & ROLLENBERGER, 2006). Os resultados apontam que as recomendações internacionais promulgadas pela ONU e a UNESCO entre 1990 e 2005 constituíram importantes fatores de difusão de parâmetros mínimos de direitos a serem assegurados às pessoas com deficiência. A participação do Brasil nesses encontros promoveu um detalhamento maior de questões previamente abordadas, além da aproximação conceitual com as recomendações internacionais. Enquanto isso, na Bolívia passou-se a detalhar a educação escolar da pessoa com deficiência a partir da idéia de equiparação de oportunidades, com diversos tópicos versando sobre aspectos da acessibilidade. O México cita as pessoas com deficiência em sua legislação específica para educação e desenvolveu outras garantias legais voltadas às suas necessidades de acessibilidade física, de comunicação e de convívio social. Esses dados nos levam a concluir que a relação entre a publicação das recomendações internacionais e a criação de legislação voltada à pessoa com deficiência não é um processo linear, mas sim dinâmico, num movimento de estímulo, absorção e troca de conceitos, num relacionamento orgânico - e não hierárquico, que envolve ainda as próprias leis locais e discussões de movimentos e lideranças da área. As recomendações internacionais, portanto, servem de motivação, inspiração, orientação e marco para a elaboração de garantias legais, ou seja, um referencial a ser incorporado pela legislação, que chega a ter peso de lei internacional, particularmente quando os países são signatários desses documentos. Como possíveis desdobramentos deste estudo, destacam-se a pesquisa em torno da relação entre os avanços na legislação e os aspectos da cultura de acessibilidade incorporados à realidade cotidiana dos países analisados, bem como um aprofundamento acerca das contribuições do Desenho Universal e da Ergonomia na promoção da educação escolar da pessoa com deficiência. / This is a qualitative research of documental analysis. Its object is the current accessibility legislation between 1990 and 2005 in three Latin American countries: Brazil, Bolivia and Mexico. The goals on this work are: to analyse the accessibility legislation of those countries and to compare their contents and meanings, checking the relations between then and the international recommendations related to the theme during the period. The legal documents were approached from three categories, developed for this research: physical / architectural accessibility, assistive technology for school education and accessibility culture. The inquiries during the development of this study aimed to identify: the specificities on the right to education for people with disabilities (MAZZOTA, 2006; ROMITA, 2007; GARCIA, 2004; ODEH, 2000; STAINBACK & STAINBACK 1999; AINSCOW, 2001; SASSAKI, 2004; FÁVERO, 2004; SOUSA & PRIETO, 1999; PRIETO, 2003), the role of international recommendations on the elaboration process of legal warranties of accessibility for the education of this (IDRM, 2004; CEPAL, 2003) and the elements that constitutes the notion of accessibility as an equiparation of opportunities factor at the school education for them (NUNES & SOBRINHO, 2007; OLIVER, 1990; CONVINGTON & HANNAH, 1997; SCIS, 2006; LENT, 2005; HOGETOP & SANTAROSA, 2001; NASAA, 2005; TESSARO, 2004; MOYSÉS, 2001; MANZINI, 2006; GRANDJEAN, 1998; AMARAL & NOGUEIRA, 2006; MARTINS NETO & ROLLENBERGER, 2006). The results show that the international recommendations promoted by United Nations and Unesco, between 1990 and 2005, has been working as important tools on the diffusion of parameters for the warranty of the rights of people with disabilities. The participation of Brazil on the international meetings has promoted a quite good specification of questions previously mentioned and the conceptual approximation with the international recommendations as well. At the Bolivian legislation, the school education has become more detailed, approaching the idea of equalization of opportunities, with some topics touching on accessibility aspects. In the school specific legislation of Mexico we have found some quotes on the rights of people with disabilities and concise but well detailed warranties of physical, social and communication access. These data take us to the conclusion that the relationship between the international recommendations and the elaboration process of legal warranties at those countries is not linear, but dynamical, in movement of conceptual stimulation, absorption and exchange, resulting in an organic - and not hierarchical - relation, that involves the local laws and the organized movements and leaderships discussions. So, the international recommendations works as motivational, inspirational, orientation and mark for the mentioned process, as well a reference to be incorporated by the legislation, with status of international law, particularly when the country signs their compromise with the international documents. We can point as possible researches from this, the relationship between the legislation and the accessibility culture aspects incorporated on daily life in the analyzed countries, or a deepen in the knowledge on the specific contributions of Universal Design and Ergonomics in the process of promotion the school education for people with disability.

Submitted by Alexandre Lima Baião (alexandrelimabaiao@gmail.com) on 2013-07-06T01:46:30Z No. of bitstreams: 1 Dissertação.pdf: 1352756 bytes, checksum: bd77fab94b1c905a8ed0aadf9d09fe08 (MD5) / Rejected by ÁUREA CORRÊA DA FONSECA CORRÊA DA FONSECA (aurea.fonseca@fgv.br), reason: Prezado Alexandre, Substituir no PDF a folha de ata pela folha de assinatura dos membros da Banca Examinadora (enviada por e-mail) e submeter novamente. Att. ÁUREA SRA on 2013-07-10T19:15:24Z (GMT) / Submitted by Alexandre Lima Baião (alexandrelimabaiao@gmail.com) on 2013-07-10T20:02:54Z No. of bitstreams: 1 Dissertação.pdf: 1364852 bytes, checksum: 8a8d0cb3da03120099b94df341f00c39 (MD5) / Approved for entry into archive by ÁUREA CORRÊA DA FONSECA CORRÊA DA FONSECA (aurea.fonseca@fgv.br) on 2013-07-12T15:47:02Z (GMT) No. of bitstreams: 1 Dissertação.pdf: 1364852 bytes, checksum: 8a8d0cb3da03120099b94df341f00c39 (MD5) / Approved for entry into archive by Marcia Bacha (marcia.bacha@fgv.br) on 2013-07-15T14:25:54Z (GMT) No. of bitstreams: 1 Dissertação.pdf: 1364852 bytes, checksum: 8a8d0cb3da03120099b94df341f00c39 (MD5) / Made available in DSpace on 2013-07-15T14:26:12Z (GMT). No. of bitstreams: 1 Dissertação.pdf: 1364852 bytes, checksum: 8a8d0cb3da03120099b94df341f00c39 (MD5) Previous issue date: 2013-04-10 / With decentralization w h ich has chara cterized the brazilian federation in the last fe w decades, the municipalities received more assignments and responsibilities, implementing public policies and providing basic services for population. However, since the own municipal revenues are capable of fund ing only partially these activities, it bec omes necessary a high volume of grants that flow s from central levels to sub national levels of government. Furthermore , Brazil is a country with a vast and heterogeneous territory, where municipalities with different self financing capability, as well as d ifferent demands from population, coexist in the same federalist system. In light of this, it becomes fundamental studying the grants distribution, verifying if the municipalities that need more financial support have been the effectively benefited. This p rocess of reducing the horizontal disparities that emerge from different tax bases and local demands is called fiscal equalization. The fiscal equalization allows residents in different municipalities receiving the same public service level given the tax c harge assumed by them (net fiscal benefit), it means, the equalization promotes the equity in the public services provision, as well as avoids the allocational inefficiency derived from migrations encouraged by fiscal benefits. To create the fiscal equaliz ation , grants must benefit those municipalities with less er self financing capability and greater fiscal needs associated with costs and demands for public services. In this sense, this study aims to assess the effect of intergovernmental transfers in the municipalities’ fiscal equalization, considering the main proxies of fisca l capacity – potential of creating own revenue – and fiscal need – volume of resources demanded in the municipality due region’s and population’s characteristics. The analysis is rea lized to each transfer’s group, ranging from those with an essentially redistributive finality, to those predominantly devolutive , as the 'cota - parte de ICMS'. The results show that some transfers, as FPM, contribute little to fiscal equalization, in spite of the redistributive nature implicit in this grant, as well as some conditional transfers, as FUNDEB, although they don’t aim correct the horizontal disparities in the capability of local government realizing their function s , can imply a positive effect to fiscal equalization in the federation’s local level. Another important result emerge d from analysis is the Bolsa - família transfer’s effect in the equali zation, because this transfer minimize the distortions realized by all other grants distributed to mu nicipalities. The Bolsa - família, although it’s not a intergovernmental transfer, was included in the analysis since it’s represents an expressive amount of resources, competes for resources with others grants and has a potential effect similar to the other intergovernmental transfers in the scope of fiscal equalization, given that releases resources in the local budget that, otherwise, could be committed with the local social policy. Another relevant result is the observation that voluntary transfers affect less the equalization, it means, they don’t contribute to this aim nor prejudice the horizontal disparities reduction, being relatively neutral or less intervenient in relation demands and fiscal capacity of local governments, probably because they don’t follow criteria , neither economics, as the ICMS, nor redistributive, as FPM. Instead, these transfers follow political criteria, as indicated by recent political science literature. / Com a descentralização que caracterizou a federação brasileira nas últimas décadas, os municípios receberam maiores atribuições e responsabilidades, implementando políticas públicas e provendo serviços básicos à população. Contudo, uma vez que as receitas próprias municipais são capazes de custear apenas parcialmente estas atividades, torna-se necessário um volume elevado de transferências que fluem dos níveis centrais aos municípios. Além do mais, o Brasil é um país de território vasto e heterogêneo, em que municípios com distintas capacidades de autofinanciamento, bem como diferentes demandas por serviços públicos, convivem no mesmo regime federativo. Diante deste quadro, torna-se fundamental estudar a distribuição dos recursos das transferências, verificando se os municípios que mais necessitam de suporte financeiro têm sido os efetivamente beneficiados. À este processo de reduzir as disparidades horizontais provenientes de diferenças nas bases tributárias e demandas locais dá-se o nome de equalização fiscal. A equalização fiscal permite que municípes de diferentes jurisdições recebam o mesmo nível de serviços públicos para dada carga tributária assumida por eles (net fiscal benefit), ou seja, a equalização promove a equidade na provisão dos serviços públicos, além de evitar a criação de ineficiência alocativa derivada de migrações motivadas por benefícios fiscais. Para criar a equalização fiscal as transferências devem beneficiar aqueles municípios com menor capacidade de autofinanciamento e maiores necessidades fiscais atreladas à custos e demandas pelos serviços públicos. Neste sentido, este trabalho busca avaliar o efeito das transferências intergovernamentais na equalização fiscal dos municípios, considerando as principais proxies de capacidade fiscal – potencial de geração de receita própria – e necessidade fiscal – volume de recursos demandados em virtude das características da região e da população do município. A análise é realizada para cada grupo de transferências, desde aquelas com finalidade essencialmente redistributiva como o FPM até aquelas predominantemente devolutivas, como a cota-parte de ICMS. Os resultados mostram que algumas transferências como o FPM contribuem pouco para a equalização fiscal, apesar do objetivo de natureza redistributiva implícito neste repasse, assim como algumas transferências condicionais, como o FUNDEB, apesar de não almejarem especificamente corrigir as disparidades horizontais na capacidade dos municípios realizarem suas funções, podem significar um efeito positivo para a equalização fiscal no nível municipal da federação. Outro resultado importante que desponta na análise é o efeito da transferência do Bolsa-família na equalização, pois esta transferência consegue atenuar as distorções realizadas pelas demais transferências distribuídas aos municípios. O Bolsa-família, apesar de não ser uma transferência intergovernamental, foi incorporada na análise por representar um expressivo volume de recursos, por concorrer com recursos de outras transferências e ainda ter efeito potencial semelhante ao das demais transferências intergovernamentais no âmbito da equalização fiscal, uma vez que libera recursos no orçamento do governo local que, do contrário, poderiam estar comprometidos com a política local de assistência social. Outro resultado é a observação de que as transferências voluntárias afetam menos a equalização, ou seja, não contribuem para a consecução deste objetivo nem prejudicam a redução das disparidades horizontais, sendo relativamente neutras ou menos intervenientes em relação às demandas e capacidade de arrecadação dos municípios, provavelmente por não seguirem critérios, nem econômicos, como o ICMS, nem redistributivos, como o FPM, e sim critérios políticos, como apontado pela literatura de ciência política.

[pt] Este trabalho está relacionado ao problema da utilização eficiente da órbita de satélite geoestacionários. Neste problema, os satélites devem ser alocados adequadamente na órbita, obedecendo a limites de interferência máxima, de modo a satisfazer os requisitos de desempenho dos sistemas. Algumas técnicas para a determinação das posições orbitais de satélites existentes e planejados são mencionadas. Um novo modelo matemático para a otimização das posições orbitais dos satélites, baseado na minimização de uma função objetivo associada à interferência total que afeta cada um dos sistemas, é proposto. Finalmente, alguns resultados obtidos através da aplicação deste modelo são analisados e comparados a outros resultados disponíveis. / [en] This work is related to the problem of efficiently using the geoestationary satellite orbit in an interference limited environment. Some techniques to determine the orbital positions of existing and planned satellites are mentioned. A new mathematical model for optimizing satellite orbital positions based on the minimization of an objective function associated to the total interference affecting each system is proposed. Finally, results obtained through the application of this model are analysed and compared to other available results.