Frequency-domain receiver design for doubly-selective channels

This work is devoted to the broadband wireless transmission techniques, which are serious candidates to be implemented in future broadband wireless and cellular systems, aiming at providing high and reliable data transmission and concomitantly high mobility. In order to cope with doubly-selective channels, receiver structures based on OFDM and SC-FDE block transmission techniques, are proposed, which allow cost-effective implementations, using FFT-based signal processing. The first subject to be addressed is the impact of the number of multipath components, and the diversity order, on the asymptotic performance of OFDM and SC-FDE, in uncoded and for different channel coding schemes. The obtained results show that the number of relevant separable multipath components is a key element that influences the performance of OFDM and SC-FDE schemes. Then, the improved estimation and detection performance of OFDM-based broadcasting systems, is introduced employing SFN (Single Frequency Network) operation. An initial coarse channel is obtained with resort to low-power training sequences estimation, and an iterative receiver with joint detection and channel estimation is presented. The achieved results have shown very good performance, close to that with perfect channel estimation. The next topic is related to SFN systems, devoting special attention to time-distortion effects inherent to these networks. Typically, the SFN broadcast wireless systems employ OFDM schemes to cope with severely time-dispersive channels. However, frequency errors, due to CFO, compromises the orthogonality between subcarriers. As an alternative approach, the possibility of using SC-FDE schemes (characterized by reduced envelope fluctuations and higher robustness to carrier frequency errors) is evaluated, and a technique, employing joint CFO estimation and compensation over the severe time-distortion effects, is proposed. Finally, broadband mobile wireless systems, in which the relative motion between the transmitter and receiver induces Doppler shift which is different or each propagation path, is considered, depending on the angle of incidence of that path in relation to the direction of travel. This represents a severe impairment in wireless digital communications systems, since that multipath propagation combined with the Doppler effects, lead to drastic and unpredictable fluctuations of the envelope of the received signal, severely affecting the detection performance. The channel variations due this effect are very difficult to estimate and compensate. In this work we propose a set of SC-FDE iterative receivers implementing efficient estimation and tracking techniques. The performance results show that the proposed receivers have very good performance, even in the presence of significant Doppler spread between the different groups of multipath components.

A import��ncia da comunica����o estrat��gica na altera����o de comportamentos na sociedade : o caso Sociedade Ponto Verde

A comunica����o estrat��gica poder�� ser entendida como a comunica����o alinhada com a estrat��gia global de uma organiza����o para alcan��ar o seu posicionamento estrat��gico. Ou seja, para alcan��ar o sucesso, uma organiza����o precisa de ter uma comunica����o consistente com a sua identidade e, ao mesmo tempo, adequada ao seu p��blico-alvo e ao tipo de sector onde se insere. S�� desta forma consegue conquistar a confian��a e fidelidade dos consumidores, essenciais para o alcance dos objectivos. Em rela����o �� altera����o comportamentos, �� essencial que as empresas costruam uma estrat��gia de comunica����o coerente e consistente, adaptando as mensagens e os p��blicos-alvo escolhidos. Neste ��mbito da altera����o de comportamentos, estudou-se neste trabalho a Sociedade Ponto Verde (SPV), uma associa����o portuguesa sem fins lucrativos, que actua no ��mbito da gest��o e reciclagem de res��duos de embalagens. Procurou estudar-se a evolu����o da sua comunica����o ao longo dos anos e a forma como adaptou as suas mensagens, de forma a conseguir incutir na sociedade portuguesa a import��ncia do comportamento de reciclagem de res��duos. Neste estudo, procedeu-se a uma an��lise individualizada de cada uma das campanhas de comunica����o da SPV e, posteriormente, aplicou-se um inqu��rito por question��rio, para verificar a efic��cia das mesmas campanhas perante o p��blico-alvo. A metodologia utilizada neste trabalho consistiu na distribui����o de um inqu��rito por question��rio online, que permitiu recolher uma amostra probabil��stica por conveni��ncia. Em seguida, recolhidos e tratados os dados referentes ��s 482 respostas recebidas, utilizou-se o programa SPSS (Stastitical Package for the Social Sciences) para analisar, tratar e discutir os resultados obtidos. Estes resultados demonstraram que, de facto, n��o houve uma grande percentagem de inquiridos que se lembram das campanhas da SPV. Os resultados s��o positivos e n��o desmentem a qualidade e coer��ncia das mensagens, mas a verdade �� que a percentagem de indiv��duos que n��o se lembra de algumas campanhas chega a ser elevada (em especial nas campanhas iniciais da organiza����o, quando existia falta de uma estrat��gia coerente). Justifica-se este facto, em parte, pelo excesso de informa����o e est��mulos a que as pessoas est��o sujeitas, pelo que a informa����o que ret��m n��o fica para sempre, acabando por dar lugar a outras informa����es. Os indiv��duos s��o inconscientemente selectivos com a informa����o que processam e guardam, pois n��o seria poss��vel guardar toda a informa����o que lhes �� transmitida. No que diz respeito �� comunica����o estrat��gica que visa alterar uma atitude e, posteriormente, um comportamento, conclui-se que, no geral, o comportamento das pessoas inquiridas aparenta ter sido influenciado pela comunica����o da SPV, caso contr��rio, as respostas afirmativas quanto �� reciclagem e de concord��ncia com algumas das afirma����es teriam sido inferiores. Ou seja, mesmo reconhecendo o car��cter um pouco enviesado da amostra (n��o dever�� ser considerada representativa da popula����o portuguesa), �� poss��vel dizer que a estrat��gia de comunica����o da SPV (em especial a partir de 2005) foi eficiente. Palavras-

How can digital help biotherm growing in the Portuguese selective skincare channel?

Branding Lab

Connect to success- consulting program of the U.S. embassy Lisbon creation of a business plan for ���Quinta dos I���s���

The purpose of this project is to analyse and evaluate if the rural tourism cottage Quinta dos I���s will be profitable within the first five years of operation. It starts with a brief description of the business, followed by an industry analysis of the rural tourism market in Portugal and an intensive competitor analysis to evaluate Quinta dos I���s��� competitive advantages. The project then defines a marketing plan to generate awareness and establish the cottage in the market. Finally, a financial analysis is performed to examine the outcome of Quinta dos I���s��� recommended strategic activities. The results of this project show that the cottage is profitable after the first year of operation and expects to grow annually.

A multi-criteria decision support system for a routing problem in waste collection

Autor proof

Programa de atividade f��sica e sa��de - Projeto M&M: an��lise da interven����o relativamente ao per��metro de cintura e aptid��o cardiorrespirat��ria

Relat��rio de est��gio de mestrado em Ensino de Educa����o F��sica nos Ensinos B��sico e Secund��rio

O l��dico como estrat��gia de consolida����o e revis��o de conhecimentos na aula de L��ngua Estrangeira

Relat��rio de est��gio de mestrado em Ensino do Portugu��s no 3�� Ciclo do Ensino B��sico e no Ensino Secund��rio e de Espanhol nos Ensinos B��sico e Secund��rio

Industrial engineering and management curriculum profile: Developing a framework of competences

This paper presents a framework of competences developed for Industrial Engineering and Management that can be used as a tool for curriculum analysis and design, including the teaching and learning processes as well as the alignment of the curriculum with the professional profile. The framework was applied to the Industrial Engineering and Management program at University of Minho (UMinho), Portugal, and it provides an overview of the connection between IEM knowledge areas and the competences defined in its curriculum. The framework of competences was developed through a process of analysis using a combination of methods and sources for data collection. The framework was developed according to four main steps: 1) characterization of IEM knowledge areas; 2) definition of IEM competences; 3) survey; 4) application of the framework at the IEM curriculum. The findings showed that the framework is useful to build an integrated vision of the curriculum. The most visible aspect in the learning outcomes of IEM program is the lack of balance between technical and transversal competences. There was not almost any reference to the transversal competences and it is fundamentally concentrated on Project-Based Learning courses. The framework presented in this paper provides a contribution to the definition of IEM professional profile through a set of competences which need to be explored further. In addition, it may be a relevant tool for IEM curriculum analysis and a contribution for bridging the gap between universities and companies.

Impact of an occupational gym program on flexibility in office workers

The problem of work-related musculoskeletal disorders is a rising concern in the companies. Thus, occupational gym has emerged as a possible solution to this problem because it leads to changes in the lifestyle by promoting health and physical activity. In this regard, this study purposes to evaluate the impact of an occupational gym program in the neck and shoulder flexibility in office workers. In order to evaluate the levels of flexibility, a universal goniometer was used for pre and post occupational gym program implementation. The program had an extension of three months, with 15 minutes sessions twice a week. The sample consisted in an intervention group comprised of 30 elements and a control group composed of 8 elements. The results suggest that there were improvements in flexibility at the cervical spine and shoulder segments levels. The increase on flexibility between the two time points in the intervention group was significant, unlike the control group that presented only slight improvements.

Temporal analysis of CHAVE collection

Lecture Notes in Computer Science, 9309

List of type-specimens of Isoptera (Insecta) in the collection of the Museu Paraense Em��lio Goeldi, State of Par��, Brazil

The collection of the Museu Paraense Em��lio Goeldi (MPEG), in the city of Bel��m, State of Par��, Brazil, has 65 samples of type-specimens of Isoptera, representing 26 species (21 holotypes and 5 paratypes) of 18 genera. This paper lists the number of specimens of each caste in each type series, type localities with geographical coordinates, collectors, and dates of collection.

Intervention program on adolescent���s creativity representations and academic motivation

Creativity and its promotion are widespread concerns in education. However, few efforts have been made to implement intervention programs designed to promote creativity and other related aspects (e.g., academic motivation). The Future Problem Solving Program International (FPSPI), aimed for training creativity representations and creative problem solving skills in young people, has been one of the most implemented programs. This intervention���s materials and activities were adapted for Portuguese students, and a longitudinal study was conducted. The program was implemented during four months, in weekly sessions, by thirteen teachers. Teachers received previous training for the program and during the program���s implementation. Intervention participants included 77 Basic and Secondary Education students, and control participants included 78 equivalent students. Pretest-posttest measures of academic motivation and creativity representations were collected. Results suggest a significant increase, in the intervention group, in motivation and the appropriate representations of creativity. Practical implications and future research perspectives are presented.