Research funding is a term generally covering any funding for scientific research, in the areas of natural science, technology, and social science. Different methods can be used to disburse funding, but the term often connotes funding obtained through a competitive process, in which potential research projects are evaluated and only the most promising receive funding. It is often measured via Gross domestic expenditure on R&D (GERD). Most research funding comes from two major sources, corporations (through research and development departments) and government (primarily carried out through universities and specialized government agencies; often known as research councils). A smaller amount of scientific research is funded by charitable foundations, especially in relation to developing cures for diseases such as cancer, malaria, and AIDS. According to the Organisation for Economic Co-operation and Development (OECD), more than 60% of research and development in scientific and technical fields is carried out by industry, and 20% and 10% respectively by universities and government. Comparatively, in countries with less GDP such as Portugal and Mexico, the industry contribution is significantly lower. The government funding proportion in certain industries is higher, and it dominates research in social science and humanities. In commercial research and development, all but the most research-oriented corporations focus more heavily on near-term commercialization possibilities rather than "blue-sky" ideas or technologies (such as nuclear fusion). History Conducting research requires funds. Over the past years, funding for research has gone from a closed patronage system to which only few could contribute, to an open system with multiple funding possibilities. In the early Zhou dynasty (-c. 6th century to 221 BCE), government officials used their resources to fund schools of thought of which they were patron. The bulk of their philosophies are still relevant, including Confucianism, Legalism and Taoism. During the Mayan Empire (-c. 1200-1250), scientific research was funded for religious purposes. The Venus Table is developed, showing precise astronomical data about the position of Venus in the sky. In Cairo (-c. 1283), the Mamluk Sultan Qalawun funded a monumental hospital, patronizing the medical sciences over the religious sciences. Furthermore, Tycho Brahe was given an estate (-c. 1576 – 1580) by his royal patron King Frederik II, which was used to build Uraniborg, an early research institute. The age of the academies In 1700-1799, scientific academies became central creators of scientific knowledge. Funded by state sponsorship, societies are still free to manage scientific developments. Membership is exclusive