Extensive Comparisons of Optical Fast-OFDM and Conventional Optical OFDM for Local and Access Networks

A performance comparison between a recently proposed novel technique known as fast orthogonal frequency-division multiplexing (FOFDM) and conventional orthogonal frequency-division multiplexing (OFDM) is undertaken over unamplified, intensity-modulated, and direct-detected directly modulated laser-based optical signals. Key transceiver parameters, such as the maximum achievable transmission capacity and the digital-to-analog/analog-to-digital converter (DAC/ADC) effects are explored thoroughly. It is shown that, similarly to conventional OFDM, the least complex and bandwidth efficient FOFDM can support up to similar to 20 Gb/s over 500 m worst-case multimode fiber (MMF) links having 3 dB effective bandwidths of similar to 200 MHz X km. For compensation of the DAC/ADC roll-off, a power-loading (PL) algorithm is adopted, leading to an FOFDM system improvement of similar to 4 dB. FOFDM and conventional OFDM give similar optimum DAC/ADC parameters over 500 m worst-case MMF, while over 50 km single-mode fiber a maximum deviation of only similar to 1 dB in clipping ratio is observed due to the imperfect chromatic dispersion compensation caused by one-tap equalizers.

Methodological contributions towards the study of health care production: lessons from a research study on barriers and access in mental health

This article presents methodological contributions and a conceptual innovation for thinking about the production of health care, stemming from a study on access and barriers in mental health carried out in the municipality of Campinas (São Paulo, Brazil). The study used a cartographic approach and, after an initial identification of the most complex cases (on the part of the teams of workers), adopted the users as guides to explore the different levels of production of their lives and to evaluate the possibility of forming a network of existential connections that produce life as a fundamental analyzer of access or barriers to care.

Inequalities in access to education and healthcare

The burden of disease is borne by those who suffer as patients but also by society at large, including health service providers. That burden is felt most severely in parts of the world where there is no infrastructure, or foreseeable prospects of any, to change the status quo without external support. Poverty, disease and inequality pervade all the activities of daily living in low-income regions and are inextricably linked. External interventions may not be the most appropriate way to impact on this positively in all circumstances, but targeted programmes to build social capital, within and by countries, are more likely to be sustainable. By these means, basic oral healthcare, underpinned by the primary healthcare approach, can be delivered to more equitably address needs and demands. Education is fundamental to building knowledge-based economies but is often lacking in such regions even at primary and secondary level. Provision of private education at tertiary level may also introduce its own inequities. Access to distance learning and community-based practice opens opportunities and is more likely to encourage graduates to work in similar areas. Recruitment of faculty from minority groups provides role models for students from similar backgrounds but all faculty staff must be involved in supporting and mentoring students from marginalized groups to ensure their retention. The developed world has to act responsibly in two crucial areas: first, not to exacerbate the shortage of skilled educators and healthcare workers in emerging economies by recruiting their staff; second, they must offer educational opportunities at an economic rate. Governments need to lead on developing initiatives to attract, support and retain a competent workforce.

Properties of BaBi2Ta2O9 thin films prepared by chemical solution deposition technique for dynamic random-access memory applications

We report on the properties of BaBi2Ta2O9 (BBT) thin films for dynamic random-access memory (DRAM) and integrated capacitor applications. Crystalline BBT thin films were successfully fabricated by the chemical solution deposition technique on Pt-coated Si substrates at a low annealing temperature of 650°C. The films were characterized in terms of structural, dielectric, and insulating properties. The electrical measurements were conducted on Pt/BBT/Pt capacitors. The typical measured small signal dielectric constant and dissipation factor, at 100 kHz, were 282 and 0.023, respectively, for films annealed at 700°C for 60 min. The leakage current density of the films was lower than 10-9 A/cm2 at an applied electric field of 300 kV/cm. A large storage density of 38.4 fC/μm2 was obtained at an applied electric field of 200 kV/cm. The high dielectric constant, low dielectric loss and low leakage current density suggest the suitability of BBT thin films as dielectric layer for DRAM and integrated capacitor applications.

Minimal cross-subsidies approach for loss allocation in distribution networks with open access

Open access philosophy applied by regulatory agencies may lead to a scenario where captive consumers will solely face the responsibility on distribution network's losses even with Independent Energy Producers (also known as Distributed Generation) and Independent Energy Consumers connected to the system. This work proposes the utilization of a loss allocation method in distribution systems where open access is allowed, in which cross-subsidies, that appear due to the influence the generators have over the system losses, are minimized. Thus, guaranteeing to some extent the efficiency and transparency of the economic signals of the market. Results obtained through the Zbus loss allocation method adapted for distribution networks are processed in such a way that the corresponding allocation to the generation buses is divided among the consumer buses, while still considering consumers spatial characteristics. © 2007 IEEE.

Debt financing rollercoaster: Latin American and Caribbean access to international bond markets since the debt crisis, 1982-2012

Includes bibliography

Shaping the future of social protection: access, financing and solidarity

Includes bibliography

Shaping the future of social protection: access, financing and solidarity: summary

Includes bibliography

Women's contribution to equality in Latin America and the Caribbean

Includes bibliography

Organic food market in the United States: Market access opportunities for Latin American and Caribbean producers

Includes bibliography

Access to credit in Argentina

Includes bibliography

Efficiency and portability: Guidelines to develop websites

The use of the Internet as a means of ensuring greater visibility for products, services and information offered by companies is gaining strength in recent decades. However, it is known that to ensure satisfaction and subsequent virtual customer loyalty, it is necessary to guarantee the quality of the websites, allowing indiscriminate access regardless of the resources used, as well as rapid responses to possible requests. In order to assist this process, this paper presents a set of guidelines for the development of websites having quality characteristics, efficiency and portability as per ISO 9126 norms. An observational analysis of e-commerce websites was done which showed that they are inadequate as to the proposed guidelines, making them difficult to access available content. Therefore, the adoption of the proposed guidelines can greatly contribute to increasing the quality of websites and, consequently, enable quick and effective access regardless of the resources used.

Architecture for publication and universal access to smart transducers

This paper proposes a simple and powerful architecture for publication and universal access to smart transducers, through existing and established open standards. Smart transducers are put to work on standards and styles already included in the Web, exploring resources in Cloud Computing and simplifying access to data. © 2012 IEEE.

Remote laboratory experiment access via an RFID interface

In this paper, remote laboratory experiment access is considered through the use of radio frequency identification (RFID) technology. Contactless smart cards are used widely in many applications from travel cards through to building access control and inventory tracking. However, their use is considered here for access to electronic engineering experimentation in a remote laboratory setting by providing the ability to interface experiments through this contactless (wireless) connection means. A case study design is implemented to demonstrate such a means by incorporating experiment data onto a contactless smart card and accessing this via a card reader and web server arrangement. © 2012 IEEE.