Height gradient approach for occlusion detection in UAV imagery

The use of Unmanned Aerial Vehicle (UAV) significantly increased in the last years. It is used for several different applications, such as mapping, publicity, security, natural disasters assistance, environmental monitoring, 3D building model generation, cadastral survey, etc. The imagery obtained by this kind of system has a great potential. To use these images in true orthophoto generation projects related to urban scenes or areas where buildings are present, it is important to consider the occlusion caused by surface height variation, platform attitude, and perspective projection. Occlusions in UAV imagery are usually larger than in conventional airborne dataset due to the low-altitude and excessive change in orientation due to the low-weight and wind effects during the flight mission. Therefore, this paper presents a method for occlusion detection together with some obtained results for images acquired by a UAV platform. The proposed method shows potential in occlusion detection and true orthophoto generation401W4263268International Conference on Unmanned Aerial Vehicles in Geomatic

Monitoring and evaluation of human resources for health: an international perspective

BACKGROUND: Despite the undoubted importance of human resources to the functions of health systems, there is little consistency between countries in how human resource strategies are monitored and evaluated. This paper presents an integrated approach for developing an evidence base on human resources for health (HRH) to support decision-making, drawing on a framework for health systems performance assessment. METHODS: Conceptual and methodological issues for selecting indicators for HRH monitoring and evaluation are discussed, and a range of primary and secondary data sources that might be used to generate indicators are reviewed. Descriptive analyses are conducted drawing primarily on one type of source, namely routinely reported data on the numbers of health personnel and medical schools as covered by national reporting systems and compiled by the World Health Organization. Regression techniques are used to triangulate a given HRH indicator calculated from different data sources across multiple countries. RESULTS: Major variations in the supply of health personnel and training opportunities are found to occur by region. However, certain discrepancies are also observed in measuring the same indicator from different sources, possibly related to the occupational classification or to the sources' representation. CONCLUSION: Evidence-based information is needed to better understand trends in HRH. Although a range of sources exist that can potentially be used for HRH assessment, the information that can be derived from many of these individual sources precludes refined analysis. A variety of data sources and analytical approaches, each with its own strengths and limitations, is required to reflect the complexity of HRH issues. In order to enhance cross-national comparability, data collection efforts should be processed through the use of internationally standardized classifications (in particular, for occupation, industry and education) at the greatest level of detail possible

The role of wages in the migration of health care professionals from developing countries

Several countries are increasingly relying on immigration as a means of coping with domestic shortages of health care professionals. This trend has led to concerns that in many of the source countries – especially within Africa – the outflow of health care professionals is adversely affecting the health care system. This paper examines the role of wages in the migration decision and discusses the likely effect of wage increases in source countries in slowing migration flows. This paper uses data on wage differentials in the health care sector between source country and receiving country (adjusted for purchasing power parity) to test the hypothesis that larger wage differentials lead to a larger supply of health care migrants. Differences in other important factors affecting migration are discussed and, where available, data are presented. There is little correlation between the supply of health care migrants and the size of the wage differential between source and destination country. In cases where data are available on other factors affecting migration, controlling for these factors does not affect the result. At current levels, wage differentials between source and destination country are so large that small increases in health care wages in source countries are unlikely to affect significantly the supply of health care migrants. The results suggest that non-wage instruments might be more effective in altering migration flows

Developing evidence-based ethical policies on the migration of health workers: conceptual and practical challenges

It is estimated that in 2000 almost 175 million people, or 2.9% of the world's population, were living outside their country of birth, compared to 100 million, or 1.8% of the total population, in 1995. As the global labour market strengthens, it is increasingly highly skilled professionals who are migrating. Medical practitioners and nurses represent a small proportion of highly skilled workers who migrate, but the loss of health human resources for developing countries can mean that the capacity of the health system to deliver health care equitably is compromised. However, data to support claims on both the extent and the impact of migration in developing countries is patchy and often anecdotal, based on limited databases with highly inconsistent categories of education and skills. The aim of this paper is to examine some key issues related to the international migration of health workers in order to better understand its impact and to find entry points to developing policy options with which migration can be managed. The paper is divided into six sections. In the first, the different types of migration are reviewed. Some global trends are depicted in the second section. Scarcity of data on health worker migration is one major challenge and this is addressed in section three, which reviews and discusses different data sources. The consequences of health worker migration and the financial flows associated with it are presented in section four and five, respectively. To illustrate the main issues addressed in the previous sections, a case study based mainly on the United Kingdom is presented in section six. This section includes a discussion on policies and ends by addressing the policy options from a broader perspective

The interface between health sector reform and human resources in health

The relationship between health sector reform and the human resources issues raised in that process has been highlighted in several studies. These studies have focused on how the new processes have modified the ways in which health workers interact with their workplace, but few of them have paid enough attention to the ways in which the workers have influenced the reforms. The impact of health sector reform has modified critical aspects of the health workforce, including labor conditions, degree of decentralization of management, required skills and the entire system of wages and incentives. Human resources in health, crucial as they are in implementing changes in the delivery system, have had their voice heard in many subtle and open ways – reacting to transformations, supporting, blocking and distorting the proposed ways of action. This work intends to review the evidence on how the individual or collective actions of human resources are shaping the reforms, by spotlighting the reform process, the workforce reactions and the factors determining successful human resources participation. It attempts to provide a more powerful way of predicting the effects and interactions in which different "technical designs" operate when they interact with the human resources they affect. The article describes the dialectic nature of the relationship between the objectives and strategies of the reforms and the objectives and strategies of those who must implement them