I think it is a core country.
RVN=Republic of South Vietnam, a democracy.
Their is no boundary because North and South Vietnam today because they are one country, hence no border.
The core-periphery concept by John Friedman refers to the division of global economic structures into core countries with advanced economies and peripheral countries with less developed economies. Core countries have strong industries and infrastructure, while peripheral countries may rely more on agriculture or raw materials extraction. This concept helps explain power dynamics and inequalities in the global economy.
what is another type of radiator core
A 'core type' transformer core is one in which the primary windings and secondary windings are placed around each of the limbs, as opposed to a 'shell type' core, in which the two windings are placed across the centre core. A core-type core is a magnetic circuit equivalent to an electric series circuit, whereas a shell-type core is equivalent to an electric parallel circuit.
Vietnam currently uses the "đồng".
Go to google.com and click images and type vietnam,you will get the pictures of vietnam.
With a core type core, the windings surround the limbs. With a shell type core, empty limbs surround the limbs bearing the windings. From the magnetic circuit point of view, a core-type is equivalent to a series electric circuit, whereas a shell type is equivalent to a parallel electric circuit.
communist
Transformers can have a shell type or core type core. If the core surrounds the windings, it is probably a shell type. If it does not, it is a core type. If you update this answer with an email address, or leave a message on my message board I can send you some drawings that explain this better than words can.
A 'core type' transformer core is one in which the primary windings and secondary windings are placed around each of the limbs, as opposed to a 'shell type' core, in which the two windings are placed across the centre core. A core-type core is a magnetic circuit equivalent to an electric series circuit, whereas a shell-type core is equivalent to an electric parallel circuit. This is better answered with a diagram, so I suggest that you do a search on the internet.
Transformers can have a shell type or core type core. If the core surrounds the windings, it is probably a shell type. If it does not, it is a core type. If you update this answer with an email address, or leave a message on my message board I can send you some drawings that explain this better than words can.