Monday, July 04, 2005
4.3.4 Nations-in-Places (NPs)
Note: This is an excerpt from a draft of my thesis, A Computer Model of National Behavior. The introduction and table of contents are also available
4.3.4 Nations-in-Places (NPs)
NPs are considered next. An NP is not a true entity type because it is really the relation between a nation and a place. However, it has its own attributes and because of the important role it plays in the model, it typically is viewed as if it is an entity. Like the other entities it has a UID, but because it is a relation it has foreign keys that correspond to its nation UID and place UID. Similar to the nation UID and the parents of nations is national history. This list tracks the nations of which this nation in place has been part. National history like parents does not affect the simulation, but it makes the model more useful by letting the system rapidly determine the history of a NP, and where it fits in the great march of nations.
The rest of the NP attributes are subjective. They are the familiar foursome of assertiveness, aggressiveness, health, and magnitude, plus density. Because NPs can be thought of as inheriting from both nations and places, care should be taken to ensure that the precise purpose of these attributes is not confused and that every attribute adds something valuable to the system.
Specifically both magnitude and density are needed, in spite of similar definitions. The common thread of both nation magnitude and place magnitude is that it indicates the importance, with a value of zero making that thing irrelevant. The differences are pretty clear after explanations, however. The problem is a result of the originality of this thesis, meaning there is little established jargon to fall back on.
Density is a measure of a NP's existence, or put another way a nation's existence in that particular place. It is analogous to the density of an electron in a region of space. A density of one shows that the nation completely and definitely exists in a place, while a density of zero shows that a nation in no way exists in that place. The NP will struggle for more density if it has any will to live. The density index affects calculations for the nation, because it serves as a weight in the weighted average.
Magnitude shows the importance of a place for a nation. This can be seen as the emotional bond between a nation and a particular place. An example of this is Split, Croatia, which early in this century was very important to Italian politicians while being little cared for by anyone else, including Croatia. Magnitude is set to an appropriate value at the beginning of a run, and factors such as the effort a nation has put into securing a place and its length of occupancy there may affect this variable.
The final three attributes, assertiveness, aggressiveness, and health, operate just as they did with nations. Assertiveness and aggressiveness directly affect competition, while health tells if the NP is in decline in the given place. The striving between NPs occur entirely within a place, so a NP in one place cannot affect a NP in another. So while a NP may be super aggressive, it is only super-aggressive to other NPs in its same place.
It has been mentioned, but the other purpose of these attributes is to affect the weighted averages of the nation to which the NPs belong. Assertiveness is the weighted average of assertiveness, magnitude is the weighted average of magnitude and density, etc. So another reason why so many attributes have to be analogs of those in nations is that they are need to keep the model coherent.
Visually, the NPs entity type can be visualized as follows
Entity 3 (Nations-in-Places)
- Place ID
- Nation ID
- National History
Figure 9. Nations-in-Places Relation
Computer Science Thesis Index
Perhaps instead of entity, you're looking for the word, interface?
Posted by: TM Lutas | Monday, July 04, 2005
Thanks for the comment (brough back memories of the thesis defense!), but in this case the word "entity" is appropriate. "Entities" are things being modeled, so Nations, States, and Places are entities. "Relations" are how those entities are tied to each other, so Nations-in-Places is a relation of the Nation and Place entities.
These definitions are from the so-called E-R ("Entity-Relation") model, which was pioneered for early databases and is still widely used in that context.
Another way of viewing the world is the OO (Object-Oriented) model, which calls things being modeled "objects," and says that all objects have properties (details, variables, like "hot" might be the property "temperature" of the Object "the Sun") and methods (things they do, functions, like "Nova" might be the method that the Sun reaches near the end of its life).
An "interface" is a basically an alternative way for getting to the "methods" of the "object." But in this section of the thesis I outlined the attributes, not the methods, of the things being modeled.
Posted by: Dan | Tuesday, July 05, 2005