The radio frequency spectrum is not being efficiently utilized partly due to the current policy of allocating the frequency bands to specific services and users. In opportunistic spectrum access (OSA), the ``white spaces'' that are not occupied by primary users (a.k.a. incumbent users) can be opportunistically utilized by secondary users. To achieve this, we need to solve two problems: (i) primary-secondary incumbent protection, i.e., prevention of harmful interference from secondary users to primary users; (ii) secondary-secondary network coexistence, i.e., mitigation of mutual interference among secondary users. The first problem has been addressed by spectrum sensing techniques in cognitive radio (CR) networks and geolocation database services in database-driven spectrum sharing. The second problem is the main focus of this dissertation. To obtain a clear picture of coexistence issues, we propose a taxonomy of heterogeneous coexistence mechanisms for shared spectrum access. Based on the taxonomy, we choose to focus on four typical coexistence scenarios in this dissertation. Firstly, we study sensing-based OSA, when secondary users are capable of employing the channel aggregation technique. However, channel aggregation is not always beneficial due to dynamic spectrum availability and limited radio capability. We propose a channel usage model to analyze the impact of both primary and secondary user behaviors on the efficiency of channel aggregation. Our simulation results show that user demands in both the frequency and time domains should be carefully chosen to minimize expected cumulative delay. Secondly, we study the coexistence of homogeneous CR networks, termed as self-coexistence, when co-channel networks do not rely on inter-network coordination. We propose an uplink soft frequency reuse technique to enable globally power-efficient and locally fair spectrum sharing. We frame the self-coexistence problem as a non-cooperative game, and design a local heuristic algorithm that achieves the Nash equilibrium in a distributed manner. Our simulation results show that the proposed technique is mostly near-optimal and improves self-coexistence in spectrum utilization, power consumption, and intra-cell fairness. Thirdly, we study the coexistence of heterogeneous CR networks, when co-channel networks use different air interface standards. We propose a credit-token-based spectrum etiquette framework that enables spectrum sharing via inter-network coordination. Specifically, we propose a game-auction coexistence framework, and prove that the framework is stable. Our simulation results show that the proposed framework always converges to a near-optimal distributed solution and improves coexistence fairness and spectrum utilization. Fourthly, we study database-driven OSA, when secondary users are mobile. The use of geolocation databases is inadequate in supporting location-aided spectrum sharing if the users are mobile. We propose a probabilistic coexistence framework that supports mobile users by locally adapting their location uncertainty levels in order to find an appropriate trade-off between interference mitigation effectiveness and location update cost. Our simulation results show that the proposed framework can determine and adapt the database query intervals of mobile users to achieve near-optimal interference mitigation with minimal location updates. / Ph. D.

Despite the guidance provided by the Equal Employment Opportunity Commission's manual, which encourages workplaces to create policies that respect racial hair texture differences, hair-based discrimination still exists in workplace appearance policies. When Black women contest this discrimination in courts, presiding judges dismiss their racial claims by decoupling hair from the body as a racial signifier and reducing it to an aesthetic choice. While court decisions and workplace policies contend that Black women's hair's mutability separates it from immutable bodily racial markers, the words of Black women tell a different story. This study uses Black feminism qualitative inquiry to understand the meaning of natural hair and hairstyles from Black women themselves through semi-structured interviews of 16 Black women professionals who wear natural hair and hairstyles in the workplace. Results show that Black women's workplace experiences challenge the courts' assumption of Black women's hair as solely an aesthetic choice. By listening to Black women, we find that choosing to wear natural hair and hairstyles in the workplace is an embodied experience, one that makes their Black and female bodies hypervisible in white space and illuminates the systems of oppression at work within workplace appearance policies and practices that impact Black women's professional success. This study illustrates that white institutional spaces are not only racialized but gendered; that Black women have developed a strategy to combat conformity and embrace authenticity in the workplace, which I call presentability politics; and that using hair as a conduit, Black women practice Black feminist love ethic to reflect a love for self while welcoming others to also express themselves freely in the workplace.

p, li { white-space: pre-wrap; } Evoluce v přírodě slouží jako zdroj inspirace pro tuto práci . Základní myšlenkou je využití generativní síly gramatik v kombinaci s evolučním přístupem . Nabyté znalosti jsou aplikovány na hledání strategií chování v rozmanitých prostředích . Stromy chování jsou modelem , který bývá běžně použit na řízení rozhodování různých umělých inteligencí . Tato práce se zabývá hledáním stromů chování , které budou řídit jedince řešící nasledující dva problémy : upravenou verzi problému cesty koněm šachovnicí a hraní hry Pirátské kostky . Při hledání strategie hráče kostek , byla použita konkurenční koevoluce . Důvodem je obtížnost návrhu spravedlivé fitness funkce hodnotící výkony hráčů .

For almost a century, as industrial development and population growth, unrestrained use of fossil fuels, and large-scale deforestation by burning, which produce excessive greenhouse gases, causing global warming and climate change. The author of "The world is flat", Thomas Friedman calls this "the Energy-Climate Era". To confront the crisis of global warming, energy shortages and population explosion, the human need to start a new wave of green energy revolution. In the trend of globalization and regional economic integration, the cross-strait relation has come to a turning point. Taiwan is standing at a critical position, must properly cope with the new era. This case study is to explore the business strategies of a Taiwanese engineering service company in response to the Energy-Climate Era. First, focusing on the case company's top management team and its role in corporate group, to analyze the existing strategic position and business model developed since its establishment. Then, to study the case company¡¦s external environment (including globalization and regional economic integration, Energy-Climate Era, China's twelfth Five-Year-Plan and Taiwan's economic policy) and engineering services industrial environment (including market segmentation and market volume, Key Successful Factors, and Five Forces Analysis). Finally, in-depth analysis of case company's internal resources, capabilities and core competences, to summarize the case company¡¦s internal strengths and weaknesses, and external opportunities and threats, SWOT matrix analysis and strategies formulation. The study results are summarized as follows: First, the case company, with the support of corporate group and their own efforts, is now an integrated engineering company with four core businesses - environmental engineering, biotech engineering, electrical & mechanical integration, and operation & maintenance; and with more competitive advantage in the steel industry and water treatment engineering. Second, the case company¡¦s strategic positioning adjustments in response to the "Energy-Climate Era" are: (1) to consolidate existing core businesses; (2) to establish core competences in order to develop related markets of petrochemical and other industries or areas; (3) to establish core competences and business model innovation in order to seize the white space of multiple water resources development, green energy and energy saving engineering. Third, the case company¡¦s total of seventeen strategic programs can be summarized into four categories: (1) to secure the business of both inside and outside of the corporate group; (2) to integrate resources in order to enhance competitiveness; (3) to strengthen research and development of water technologies; (4) to develop air pollution and energy saving technologies. Each project department, according to their engineering professions, should work out and implement detailed action plans, which are adaptable to external situations, to integrate advantages of the three capabilities - "professional", "project management" and "financial management". Fourth, taking wastewater reclamation and energy saving projects as examples, to explore and elaborate innovative business model for case company¡¦s reference; and to provide four recommendations for organizational restructuring and three proposals for facilitating the implementation of business strategies.

The sharing of the terrestrial TV frequency spectrum with Secondary Users (SUs) is presently the focus point of numerous research efforts worldwide. In many regulatory domains, contiguous blocks of VHF and UHF spectrum are available for exclusive use by the terrestrial TV broadcasting incumbents. However, this notion is currently challenged by the spectrum management paradigm of Dynamic Spectrum Access (DSA), advocating that this spectrum may be shared on a dynamic basis with SUs. The migration of analogue terrestrial TV to Digital Terrestrial Television (DTT) has also catalysed the notion that the terrestrial TV frequency spectrum will no longer be exclusively used for terrestrial broadcasting. Some administrations have already embraced this technology, reforming spectrum policy to allow unlicensed secondary access to the Spectral Opportunities (SOs) present in the terrestrial TV frequency bands. The Independent Communications Authority of South Africa (ICASA) has expressed early interest in the possibilities of TV white space technology and its possible utility in exploiting the SOs that exist in the terrestrial TV frequency bands. Core to the issues mentioned above is the quantification of the Spectral Opportunity (SO) available. To this end, the work presented in this thesis gives a quantified estimate of the SO available in South Africa. This work is the first of its kind for the South African environment and uncovers new knowledge regarding SO in South Africa. SO is analysed and quantified on provincial and national level for three discrete points in time: before the start of dual-illumination, during dual illumination and after analogue switch-off. A system model that is able to produce the required geo-referenced field strength coverage and SO maps is conceptualised and implemented. A complete standards compliant model is implemented from scratch, verified and validated, with design decisions specific to the South African context. The analysis methodology is developed with rigour. The construction of the TV transmitter database, definition of incumbent protection criteria and development of the required analysis metrics to quantify SO are presented. SO in the VHF and UHF terrestrial TV frequency bands is quantified by expressing SO in terms of the number of available channels, weighted respectively by land area and population density. The analysis results indicate that significant SO is available for exploitation by TV white space devices in the terrestrial TV spectrum in South Africa. The effects of radio astronomy advantage areas on the SO available are also investigated. The probability of finding contiguous channels in the Very High Frequency (VHF) and Ultra High Frequency (UHF) bands is also quantified. A comparative study, comparing the SO for South Africa with related work in Europe and the United States of America (USA), is also performed. Finally, maps that visualise the SO available are constructed for the three discrete time periods evaluated. / Thesis (PhD (Computer Engineering))--North-West University, Potchefstroom Campus, 2013

The sharing of the terrestrial TV frequency spectrum with Secondary Users (SUs) is presently the focus point of numerous research efforts worldwide. In many regulatory domains, contiguous blocks of VHF and UHF spectrum are available for exclusive use by the terrestrial TV broadcasting incumbents. However, this notion is currently challenged by the spectrum management paradigm of Dynamic Spectrum Access (DSA), advocating that this spectrum may be shared on a dynamic basis with SUs. The migration of analogue terrestrial TV to Digital Terrestrial Television (DTT) has also catalysed the notion that the terrestrial TV frequency spectrum will no longer be exclusively used for terrestrial broadcasting. Some administrations have already embraced this technology, reforming spectrum policy to allow unlicensed secondary access to the Spectral Opportunities (SOs) present in the terrestrial TV frequency bands. The Independent Communications Authority of South Africa (ICASA) has expressed early interest in the possibilities of TV white space technology and its possible utility in exploiting the SOs that exist in the terrestrial TV frequency bands. Core to the issues mentioned above is the quantification of the Spectral Opportunity (SO) available. To this end, the work presented in this thesis gives a quantified estimate of the SO available in South Africa. This work is the first of its kind for the South African environment and uncovers new knowledge regarding SO in South Africa. SO is analysed and quantified on provincial and national level for three discrete points in time: before the start of dual-illumination, during dual illumination and after analogue switch-off. A system model that is able to produce the required geo-referenced field strength coverage and SO maps is conceptualised and implemented. A complete standards compliant model is implemented from scratch, verified and validated, with design decisions specific to the South African context. The analysis methodology is developed with rigour. The construction of the TV transmitter database, definition of incumbent protection criteria and development of the required analysis metrics to quantify SO are presented. SO in the VHF and UHF terrestrial TV frequency bands is quantified by expressing SO in terms of the number of available channels, weighted respectively by land area and population density. The analysis results indicate that significant SO is available for exploitation by TV white space devices in the terrestrial TV spectrum in South Africa. The effects of radio astronomy advantage areas on the SO available are also investigated. The probability of finding contiguous channels in the Very High Frequency (VHF) and Ultra High Frequency (UHF) bands is also quantified. A comparative study, comparing the SO for South Africa with related work in Europe and the United States of America (USA), is also performed. Finally, maps that visualise the SO available are constructed for the three discrete time periods evaluated. / Thesis (PhD (Computer Engineering))--North-West University, Potchefstroom Campus, 2013

NASCIMENTO, M. F. S. TV white space for digital inclusion in Brazil. 2017. 72 f. Dissertação (Mestrado em Engenharia de Teleinformática)–Centro de Tecnologia, Universidade Federal do Ceará, Fortaleza, 2017. / Submitted by Renato Vasconcelos (ppgeti@ufc.br) on 2017-09-08T18:02:47Z No. of bitstreams: 1 2017_dis_mfnascimento.pdf: 5688076 bytes, checksum: 1cc24af829d0f32975a0885021225eb2 (MD5) / Rejected by Marlene Sousa (mmarlene@ufc.br), reason: Prezado Matheus: Existe uma orientação para que normalizemos as dissertações e teses da UFC, em suas paginas pré-textuais e lista de referencias, pelas regras da ABNT. Por esse motivo, sugerimos consultar o modelo de template, para ajudá-lo nesta tarefa, disponível em: http://www.biblioteca.ufc.br/educacao-de-usuarios/templates/ Vamos agora as correções sempre de acordo com o template: 1. Na capa as informações relativas a hierarquia institucional deve ser em língua portuguesa, Nome da INSTITUIÇÃO; do CENTRO; do DEPARTAMENTO e do PROGRAMA DE PÓS-GRADUAÇÃO. Nesta ordem. 2. Na folha de rosto (que segue a capa) Apenas o titulo deve ficar em inglês as demais informações são em português. A partir da folha de rosto, todas as outras devem ficar em inglês. 3. A dedicatória está fora da distancia necessária até o final da folha. 4. A palavra Acknowledgments é em caixa alta, negrito e centralizada na folha. 5. A epígrafe está fora da distancia necessária até o final da folha. 6. O resumo deve vir antes do Abstract, mesmo quando o trabalho for em língua inglesa. A palavra resumo é em caixa alta, negrito e centralizada na folha. E a expressão Palavras-chave deve ser em negrito. 7. O sumário deve ser todo em negrito e nas seções com 3 dígitos (2.2.1) além de negrito deve ser em itálico. 8. Na lista de referências, veja o espaço entre as linhas que a ABNT determina. Coloque os nomes dos autores entrando pelo sobrenome, seguido do pré nome. Ex. Coelho Junior, Hélio. Se vc optar por abreviar os nomes em toda a lista eles devem ser abreviados. Se vc optar em colocar por extenso em toda e lista deve ficar por extenso para haver uma padronização. Os títulos das publicações devem ser destacadas com o uso do negrito (não use aspas). Com exceção dos artigos de periódicos que devem ser destacados o nome das revistas e não o titulo do artigo. Ao citar os artigos coloque as abreviações v. n. p. e não vol. no e pp. Após essas correções, enviaremos o nada consta por e-mail. Att. Marlene Rocha mmarlene@ufc.br on 2017-09-11T11:58:36Z (GMT) / Submitted by Renato Vasconcelos (ppgeti@ufc.br) on 2017-10-03T13:58:21Z No. of bitstreams: 1 2017_dis_mfnascimento.pdf: 5700235 bytes, checksum: b2c4f7caca78f61b98f57321ad854e92 (MD5) / Rejected by Marlene Sousa (mmarlene@ufc.br), reason: Prezado Renato: CORRIGIR O NOME DO ARQUIVO PARA: 2017_dis_mfsnascimento Prezado Matheus: Falta ainda vc corrigir de acordo com template 1. No sumário quando colocar em itálico as seções terciárias ( 3 dígitos) os algarismos também ficam em itálico. Vc só colocou em itálico o título da seção. 2. Na lista de referencias, Vc colocou os sobrenomes na ordem correta como falei, mas esqueceu que são TODOS em caixa alta. Corrigir em toda a lista. Ex. MUECK, M. Att. Marlene on 2017-10-03T18:55:29Z (GMT) / Submitted by Renato Vasconcelos (ppgeti@ufc.br) on 2017-10-06T12:47:58Z No. of bitstreams: 1 2017_dis_mfsnascimento.pdf: 5699792 bytes, checksum: fe9750751514aac9e39d3926f7adb7ed (MD5) / Approved for entry into archive by Marlene Sousa (mmarlene@ufc.br) on 2017-10-06T17:35:53Z (GMT) No. of bitstreams: 1 2017_dis_mfsnascimento.pdf: 5699792 bytes, checksum: fe9750751514aac9e39d3926f7adb7ed (MD5) / Made available in DSpace on 2017-10-06T17:35:53Z (GMT). No. of bitstreams: 1 2017_dis_mfsnascimento.pdf: 5699792 bytes, checksum: fe9750751514aac9e39d3926f7adb7ed (MD5) Previous issue date: 2017-07-21 / This work presents a technological opportunity to make efficient use of the spectrum and at the same time shows its importance to provide digital inclusion in Brazil. The method- ology is applied in a case study investigating the area of Cear ́a, a Brazilian state, where a significant amount of spectrum that can be unleashed via TV White Space exploitation is relevant to be considered, due to its geographic and economical conditions. These white spaces can fill up some holes in the state that do not present any mobile coverage and improve the telecommunication services in other areas. The technology concept, world regulation situation and possible applications using the resource are described throughout this work. The main purpose is to use TV White Spaces together with the LTE band, as a way to soften part of the poor coverage services of 3G, 4G. / Este trabalho apresenta uma oportunidade tecnológica para fazer o uso eficiente do espectro e, ao mesmo tempo, mostra sua importância para a inclusão digital no Brasil. A metodologia é aplicada em um estudo de caso que investiga a área do Ceará, estado brasileiro, onde uma quantidade significativa de espectro que pode ser desencadeada através da exploração dos Espaços em Brancos de TV é relevante a ser considerada, devido as suas condições geográficas e econômicas. Estes espaços em branco podem preencher alguns buracos no estado que não apresentam qualquer cobertura móvel e melhorar os serviços de telecomunicações em outras áreas. O conceito de tecnologia, situação de regulação mundial e possíveis aplicações usando o recurso são descritos ao longo deste trabalho. A principal finalidade é usar os Espaços em Brancos de TV juntamente com a banda do LTE, para tentar suavizar parte do péssimo serviço de cobertura das redes 3G e 4G.

The purpose of this study is to investigate the status quo of the integration of Information and Communication Technology (ICT) in Swaziland Mathematics and Science form four classrooms. The rationale is to understand the status in order to propose an appropriate strategy for policy and practice in education. The research design is a survey conducted in the Manzini region, the most central, largest region with the largest number of schools. The study focused on all schools that had computers for the purpose of education. There were 149 participants from 43 schools. All Mathematics, Science, and ICT teachers were included in the study, including head teachers. The study instruments were adapted from the Second Information Technology in Education Study (SITES) undertaken under the auspices of the International Association for the Evaluation of Educational Achievement. Permission to adapt South African instruments was granted through the Centre for Evaluation and Assessment at the University of Pretoria. Four types of questionnaires were adapted and used. The data was analysed using descriptive statistics. The study revealed that very little had been done by Swaziland to integrate ICT in Mathematics and Science classrooms. The status quo indicated that the Student Computer Ratio was very high (14:1). In terms of ICT literacy 67% of the ICT teachers were diploma holders, 72% of the Mathematics, 78% of the Science teachers had no ICT qualification and most of vi the learners were not competent. The computers were found old and out of date and lacking maintenance. The lack of School ICT policy as a possible factor that could explain the pedagogical use of ICT was found to be a major obstacle in the integration of ICT in the classrooms, and this was a major thematic area that has to be addressed. This is viewed as an obstacle by Mathematics, Science and ICT teachers together with their principals. The elimination of this obstacle could possibly ensure sufficient funding, appropriate knowledge and skills, efficient leadership, proficient teachers and competent students, and thereby give impetus to ICT integration in Mathematics and Science classrooms. It was then concluded that Mathematics and Science teachers do not integrate ICT in their practice, despite being core subjects. The channelling of more resources by government to ICT education was strongly recommended. / Dissertation (MEd)--University of Pretoria, 2013. / gm2014 / Science, Mathematics and Technology Education / unrestricted

An industrial control valve has been designed by Eaton (AxisPro® valve). The servo performance valve has onboard electronics that features external and internal sensor interfaces, advanced control modes and network capability. Advanced control modes are implement in the valves firmware. With the help of the white space it is possilbe to execute custom code directly on the valve that interact with these controls. Small OEM applications, like rubber moulding machines, benefit from the comination of build in controls and custom code, to provide adaptations for their special machines.

The objective of this dissertation is to propose the cross-layer spectrum management architecture for white space applications that improves the performance the main functions of the spectrum management. In the proposed cross-layer architecture, white space network devices such as white space devices and the spectrum map server cooperate to support the extended spectrum map, the inter-cell transmit power adaptation (ITPA), and the frequency-domain coexistence beacon (FCB). Upon the cross-layer architecture, firstly, white space devices (WSDs) achieve a faster search and higher accuracy in spectrum sensing with the extended spectrum map, the extended DHCP (Dynamic Host Configuration Protocol), and the FCB. Secondly, WSDs achieve the precise selection of their operating channel in spectrum decision with the extended spectrum map and the ITPA. In spectrum sharing, thirdly, the collaboration- based spectrum sharing with the ITPA achieve more accommodation of WSDs by increasing the number of channels shared between WSDs. Finally, WSDs with the FCB and the extended spectrum achieve effective spectrum mobility by obtaining the occupancy-status of channels precisely.