The Octopus switch

This chapter1 discusses the interconnection architecture of the Mobile Digital Companion. The approach to build a low-power handheld multimedia computer presented here is to have autonomous, reconfigurable modules such as network, video and audio devices, interconnected by a switch rather than by a bus, and to offload as much as work as possible from the CPU to programmable modules placed in the data streams. Thus, communication between components is not broadcast over a bus but delivered exactly where it is needed, work is carried out where the data passes through, bypassing the memory. The amount of buffering is minimised, and if it is required at all, it is placed right on the data path, where it is needed. A reconfigurable internal communication network switch called Octopus exploits locality of reference and eliminates wasteful data copies. The switch is implemented as a simplified ATM switch and provides Quality of Service guarantees and enough bandwidth for multimedia applications. We have built a testbed of the architecture, of which we will present performance and energy consumption characteristics

Laser diagnostics and minor species detection in combustion using resonant four-wave mixing

Peer reviewedPostprin

Energy-efficient wireless communication

In this chapter we present an energy-efficient highly adaptive network interface architecture and a novel data link layer protocol for wireless networks that provides Quality of Service (QoS) support for diverse traffic types. Due to the dynamic nature of wireless networks, adaptations in bandwidth scheduling and error control are necessary to achieve energy efficiency and an acceptable quality of service. In our approach we apply adaptability through all layers of the protocol stack, and provide feedback to the applications. In this way the applications can adapt the data streams, and the network protocols can adapt the communication parameters

The Design of a System Architecture for Mobile Multimedia Computers

This chapter discusses the system architecture of a portable computer, called Mobile Digital Companion, which provides support for handling multimedia applications energy efficiently. Because battery life is limited and battery weight is an important factor for the size and the weight of the Mobile Digital Companion, energy management plays a crucial role in the architecture. As the Companion must remain usable in a variety of environments, it has to be flexible and adaptable to various operating conditions. The Mobile Digital Companion has an unconventional architecture that saves energy by using system decomposition at different levels of the architecture and exploits locality of reference with dedicated, optimised modules. The approach is based on dedicated functionality and the extensive use of energy reduction techniques at all levels of system design. The system has an architecture with a general-purpose processor accompanied by a set of heterogeneous autonomous programmable modules, each providing an energy efficient implementation of dedicated tasks. A reconfigurable internal communication network switch exploits locality of reference and eliminates wasteful data copies

THE IMPACT OF HEALTH INSURANCE ON THE ACCESS TO HEALTH CARE AND FINANCIAL PROTECTION IN RURAL AREAS OF DEVELOPING COUNTRIES: CASE STUDY SENEGAL

Access to public and private health insurance in rural areas of low income countries is severely constrained by high unit cost of transaction per contract due to information asymmetries between insurance sellers and buyers. This leads to a situation in which the majority of the poor have to rely on out-of-pocket expenditures when they are ill, resulting in a high vulnerability for health shocks which negatively affect the overall risk management of the household, investment and resource allocation decisions. Recently, however, in various parts of the world community based health insurance schemes have emerged and are becoming increasingly recognized as an instrument to finance health care in poor developing countries. These mutual insurance schemes often develop out of micro-finance institutions such as the Grameen Bank in Bangladesh and are based on similar principles, i.e. relying on collective shared norms, solidarity and enforcement by peers. Taking the example of "les mutuelles de santés" (mutual health organization) in rural Senegal this paper analyzes weather or not members in a mutual health insurance scheme have actually a better access to health care than non-members. A binary probit model is estimated for the determinants of participation in a mutual and a logit/log linear model is used to measure the impact on health care utilization and financial protection. Impact is measured in terms of (a) access to health care facilities, i.e. if members frequent health facilities more often than non-members controlling for age, sex, education and the frequency of illness, which capture the need for health care and the health status and (b) the amount of out-of-pocket payments in case of health care use. The results show that while the health insurance schemes reach otherwise excluded people, the poorest of the poor in the communities are not covered. As important determinants for being a member beside income, we find that religion, belonging to a certain ethnic group, access to social capital and community characteristics are important. Regarding the impact on the access to health care, members of a mutual have better access to health care services than non-members after controlling for common individual, household and community characteristics. The probability of making use of hospitalization increases by 2 %-age points with membership and expenditure in case of need is reduced by about 50% compared with non-members. Given the results from this study, community financing schemes have the potential to improve existing the risk management capacity of rural households. To reduce identified limitations of the schemes, an enlargement of the risk pool and a scaling up/linking of the schemes is, however, a prerequisite. Appropriate instruments to be further tested should include re-insurance policies, subsidies for the poorest and developing linkages to the private sector via the promotion of group insurance policies. All these instruments call for a stronger role of public health policy in rural areas of low income countries.rural development, health insurance, impact analysis, social protection, Senegal, Health Economics and Policy, O17, I19, O55,

Social Protection in Rural Areas of Developing Countries: Investigating the Impact of Community Based Health Insurance in Rural Senegal

Community based health insurance schemes are becoming increasingly recognized as an instrument which help farmers in rural areas of low income countries to better manage health. Health risks present a permanent threat to the income earning capacity of poor people. Beside direct economic cost for treatment and lost working time, indirect cost such as a reduction in labor supply materialize which increases the vulnerability of the household. It is often hypothezised that community based health insurance improve social protection, but quantitative analysis is largely missing. Against this background, this paper analyzes if members in a mutual health insurance scheme have a better access to health care than non-members taking "les mutuelles de santes" (mutual health organization) in rural Senegal as an example. Limited dependent and log linear regressions are used to capture the impact of health insurance on the probability of visiting a health care provider and the out-of-pocket expenditure at the point of use . The results of the analysis show that while community based health insurance schemes reach otherwise excluded people, the poorest of the poor in the communities are not covered. Regarding the impact on the access to health care, members have a higher probability of using hospitalization services compared to non-members and pay substantially less when they need care. Given the results from this study, community financing schemes have the potential to improve the risk management capacity of rural households.community based health insurance, impact analysis, social protection, Senegal, Health Economics and Policy,

TECHNOLOGIES AND LOCALIZED TECHNICAL CHANGE

Heterogenous Technologies, Transformation Function, Localized Technical Change, Production Economics, Research Methods/ Statistical Methods, Q12, O33, C35,

What Do Forbidden Light-ray Fields Look Like?

Ray-optically, optical components change a light-ray field on a surface immediately in front of the component into a different light-ray field on a surface behind the component. In the ray-optics limit of wave optics, the incident and outgoing light-ray directions are given by the gradient of the phase of the incident and outgoing light field, respectively. But as the curl of any gradient is zero, the curl of the light-ray field also has to be zero. The above statement about zero curl is true in the absence of discontinuities in the wave field. But exactly such discontinuities are easily introduced into light, for example by passing it through a glass plate with discontinuous thickness. This is our justification for giving up on the global continuity of the wave front, thereby compromising the quality of the field (which now suffers from diffraction effects due to the discontinuities) but also allowing light-ray fields that appear to be (but are not actually) possessing non-zero curl and there by significantly extending the possibilities of optical design. Here we discuss how the value of the curl can be seen in a light-ray field. As curl is related to spatial derivatives, the curl of a light-ray field can be determined from the way in which light-ray direction changes when the observer moves. We demonstrate experimental results obtained with light-ray fields with zero and apparently non-zero curl