Working Paper 10. Young Lives: A Case Study of Sample Design for Longitudinal Research
2
Measuring child poverty and health: a new international study.
A major new prospective cohort study was launched in 2001 which will follow up children born into poverty in Ethiopia Vietnam Peru and the state of Andhra Pradesh in India. 2000 poor children in each country will be revisited every 3 years until they are 15 years old. The `Young Lives: an international study of childhood poverty project will strengthen research capacity in the selected developing countries and aims to be replicable in other countries interested in implementing a child cohort study. It has a conceptual framework that uses all of the outcome measures of a multidimensionally measured childhood poverty and examines risk factors at the household and community level. As the type of outcome indicators necessarily changes over time and many are age-specific this study cannot monitor trends unless an additional cohort is recruited in the second round of surveying. In addition to the outcome measures explanatory variables will be measured to explain variation. Moreover the longitudinal nature of this study will reveal causal pathways in childrens health and well-being. It is intended that such findings on causality will have a policy impact that in turn can change and improve young peoples lives.
Ceramic microwave antennas for mobile applications
Due to their medium to high permittivity values, ceramic microwave materials are attractive as building blocks for miniaturised antenna solutions. Further advantages are low dielectric losses and an excellent temperature stability of standard ceramic materials. Yet, the permittivity of the ceramic material also has a strong influence on the radiation efficiency and bandwidth of the antenna. This implies that in the design process a suitable compromise has to be found between the degree of miniaturisation on the one hand and the antenna efficiency and bandwidth on the other. We describe two approaches towards efficient miniaturised ceramic microwave antennas: the dielectric resonator antenna (DRA) with partial metallisation and the shorting post patch antenna. We focus on design steps taken to ensure both a high degree of miniaturisation and high values of the radiation efficiency, the choice of the ceramic material and the experimental performance of the antennas.