Tuesday, March 25, 2008

Split proxy server

A split proxy is a proxy implemented as two programs installed on two different computers. Since they are effectively two parts of the same program, they can communicate with each other in a more efficient way than they can communicate with a more standard resource or tool such as a website or browser. This is ideal for compressing data over a slow link, such as a wireless or mobile data service, as well as for reducing the issues regarding high latency links (such as satellite internet) where establishing a TCP connection is time consuming.

Taking the example of web browsing, the user's browser is pointed to a local proxy which then communicates with its other half at some remote location. This remote server fetches the requisite data, repackages it, and sends it back to the user's local proxy, which then unpacks the data and presents it to the browser in the standard fashion.

Tuesday, March 18, 2008

Hierarchical data model

Hierarchical data model, data is organized into a tree-like structure. The structure allows repeating information using parent/child relationships: each parent can have many children but each child only has one parent. All attributes of a specific record are listed under an entity type. In a database, an entity type is the equivalent of a table; each individual record is represented as a row and an attribute as a column. Entity types are related to each other using 1: N mapping, also known as one-to-many relationships.

Monday, March 10, 2008

Loss of Biodiversity

Farnsworth for example, has found that 25% of all prescriptions dispensed from community pharmacies in the United States from l959 to l980 contained active ingredients extracted from higher plants. A much higher percentage is found in the developing world. As many as 80% of all people living in developing countries, or roughly two thirds of the world's population, rely almost exclusively on traditional
medicines using natural substances, mostly derived from plants.

Wednesday, March 05, 2008

New Mobility Agenda

The New Mobility Agenda is an international institution which while virtual and an open collaborative was originally set up by an international working group meeting at the Abbey de Royaumont near Paris with the support of the OECD in Paris in 1974 to challenge old ideas and practices in the field of urban transport through a long term collaborative program of information exchange, education and peer support.

The Agenda today draws together the experience, expertise and support of more than four thousand individuals and groups world wide in an open collaborative peer network. One of the original proponents of this approach, Professor Mikoto Usui then director of the OECD Development Centre, referred to it in the founding meeting at the “AbbĂ© de Royaumont as an “invisible college”.