according to the Treknology Encyclopedia L-Z
# (http://www.ex-astris-scientia.org/treknology2.htm#s)
Starship is the designation for a large type of space vessel with warp drive. A starship typically consists of more than one deck and has separate departments such as the bridge, engineering or sickbay.
In our model, we use this word to designate any space vessel
A zone can be either a deep space, a planetary system, or the boundary of a Black Hole.
We assumed that a OwnStarship, when in operation (i.e. using its decision system), has 80% chance of being traveling in a Deep Space Zone, 15% in a Planetary System and 5% in the Boundaries of a Black Hole.
In our model, Black Hole Boundaries are prefered places for ambushes from attacking starships with cloaking devices, since the high magnetic turbulance generated in those zones makes it very hard to even the most advanced sensors to distinguish it from the magnetic disturbance created by a cloaking device.
This ordinary variable substitutes entities that have type !TimeStep, and was intended to comply with the context node IsA(TimeStep, t)
!T1
Original MEBN notation:
tprev=Prev(t)
PR-OWL decomposition:
equalto(tprev, Prev(t))
Inner term:
Prev(t)
In a recursive MFrag it is necessary to have a way to ground out the recursion. This is similar to a recursive algorithm such as computing x!. The definition of x! is:
0! = 1
x! = x(x-1)! for x > 0
Similarly, in a recursive node it is necessary to define the initial distribution for the dynamic BN node and then define the next distribution as a function of the previous distribution. Here is one way to do it:
1. Prev(0) = 0 and Prev(t) = t-1 for t>0
2. This creates a problem in this MFrag because now DistFromOwn(st,0) has itself as a parent! But really this isn't a problem because t=0 is also a parent and we define the distribution so that it depends on the previous value only when t>0.
In this case, we assigned to T0 the very same distribution we used in the other TimeSteps. Regarding the distribution itself, our intention was to make background disturbance a somewhat steady phenomena, thus the probabilities do not change with time. However, if cloack mode is true for any starship nearby Enterprise.
Then, the next step will be more likely to change the intensity of the disturbance, mimicking an unstable phenomena.
false
Quiddity_SPI
slot zoneMD
facet domain = [zMD_Low, zMD_Medium, zMD_High]
facet parents = [zoneNature, anyStInCloakMode, zoneMD.PREV]
facet initialState = [.70, .20, .10]
facet distribution = function zn, ascm, znp {
switch zn {
zN_BlackHoleBoundary:
switch ascm{
true:
switch znp{
zMD_Low: [.02, .05, .93];
zMD_Medium: [.08, .04, .88];
zMD_High: [.12, .18, .70];
};
false: [.07, .11, .82];
};
zN_DeepSpace:
switch ascm{
true:
switch znp{
zMD_Low: [.70, .18, .12];
zMD_Medium: [.80, .05, .15];
zMD_High: [.83, .15, .02];
};
false: [.85, .10, .05];
};
zN_PlanetarySystem:
switch ascm{
true:
switch znp{
zMD_Low: [.15, .37, .48];
zMD_Medium: [.30, .20, .50];
zMD_High: [.26, .39, .35];
};
false: [.25, .30, .45];
};
}
}
1
2
!ZMD_Medium
!ZMD_High
!ZMD_Low
1
Original MEBN notation:
t=!T0
Decomposed to:
EqualTo(t, !T0)
!T0
2
1
In MEBN models, this context node its satisfied when the variable "z" is substituted by a unique identifier of an entity that has Type equal to "Zone".
In a Quiddity model, this node is translated to a slot named "starshipZone" which has the Frame "Zone" as its domain and works as a "pointer" to slots from Frame "Zone" that are parents from slots in the current frame ("Starship").
1
!Starship_Label
That is the Enterprise
!ST0
!ST1
!ST4
!ST3
!ST2
!SR7
!SR3
!SensorReport_Label
!SR2
!SR1
!SR0
!SR6
!SR5
!SR4
!Zone_Label
!Z0
!Z1
1
In MEBN models, this context node its satisfied when the variable "z" is substituted by a unique identifier of an entity that has Type equal to "Zone".
In a Quiddity model, this node is translated to a slot named "starshipZone" which has the Frame "Zone" as its domain and works as a "pointer" to slots from Frame "Zone" that are parents from slots in the current frame ("Starship").
Original MEBN notation:
z=StarshipZone(st)
PR-OWL decomposition:
equalto(z, StarshipZone(st))
Inner terms:
StarshipZone(st)
2
1
1
This RV establishes the relationship between a given zone and the likelihood of having friendly starships within OwnStarship's sensor range. Following the very same rationale of node ZoneEShips, we assume that there is a prior probability in the number of friendly or neutral starships to appea into OwnStarship's sensor range given the nature of the zone it is navigating into.
!ZFS_1
!ZFS_0
!ZFS_MoreThan3
!ZFS_2
!ZFS_3
PR-OWL_MEBN
true
absurd
.05
.01
.007
.98
.002
.001
!ZN_DeepSpace
!ZN_BlackHoleBoundary
.0035
.99
.005
.0005
.001
.10
.15
.50
We assume that unlike enemies, friendly starships do not care about being in places suitable for an ambush. Therefore, its probability distribution will reflect this fact. As an example, in a Black Hole Boundary, the chances of finding at least one friendly starship are five times smaller than to find an ambushing enemy vessel.
false
false
Quiddity_SPI
We assume that unlike enemies, friendly starships do not care about being in places suitable for an ambush. Therefore, its probability distribution will reflect this fact. As an example, in a Black Hole Boundary, the chances of finding at least one friendly starship are five times smaller than to find an ambushing enemy vessel.
slot zoneFShips
facet domain = [zFS_0, zFS_1, zFS_2, zFS_3, zFS_MoreThan3]
facet parents = [zoneNature]
facet distribution = function zn {
zN_BlackHoleBoundary: [.99, .005, .0035, .001, .0005];
zN_DeepSpace: [.98, .01, .007, .002, .001];
zN_PlanetarySystem: [.50, .20, .15, .10, .05];
}
!ZES_1
!ZES_2
!ZES_3
!ZES_0
!ZES_MoreThan3
This RV establishes the relationship between a given zone and the likelihood of having enemy starships within OwnStarship's sensor range.
In other words, it is the probable number of enemy ships into sensor range we assume to find in a given zone.
This means we consider that exists a prior probability of finding an enemy starship given the nature of the zone in which OwnStarship is navigating through.
In this model, we restrained the infinitely possible number of starships to only five states. That is, we assume that it is unlikely to find four or more hostile ships in that area, so most of the probability distribution mass for this RV will be restricted to the states None, One, Two, and Three, while the remaining probability will be restricted to the aggregating state MoreThan3.
node Z_ZoneEShips {
kind = NATURE;
discrete = TRUE;
states = (absurd);
parents = (PHarm1, OpSpecies);
title = "ZoneEShips(z)";
whenchanged = 1107474628;
belief = (1);
visual V2 {
center = (156, 258);
dispform = LABELBOX;
height = 3;
};
true
Netica_DNE
false
Quiddity_SPI
slot zoneEShips
facet domain = [zES_0, zES_1, zES_2, zES_3, zES_MoreThan3]
facet parents = [zoneNature]
facet distribution = function zn {
zN_BlackHoleBoundary: [.95, .03, .01, .007, .003];
zN_DeepSpace: [.98, .01, .007, .002, .001];
zN_PlanetarySystem: [.60, .15, .12, .08, .05];
1
1
ZoneMD(z, t) assesses the value of the magnetic disturbance in Zone "z" at the current TimeStep "t".
This value is influenced by the MD in the previous TimeStep (tprev), the fact of whether there is or there is not a starship in cloak mode nearby, and the nature of the space zone in which the starship is located.
The input node t=!T0 is used to "anchor" the time recursion.
2
2
1
This ordinary variable substitutes entities that have type !TimeStep, and was intended to comply with the context node IsA(TimeStep, tprev)
!T2
!TimeStep_Label
!T3
!T4
1
Inner term of context node tprev=Prev(t).
A zone can be either a deep space, a planetary system, or the boundary of a Black Hole.
We assumed that a OwnStarship, when in operation (i.e. using its decision system), has 80% chance of being traveling in a Deep Space Zone, 15% in a Planetary System and 5% in the Boundaries of a Black Hole.
In our model, Black Hole Boundaries are prefered places for ambushes from attacking starships with cloaking devices, since the high magnetic turbulance generated in those zones makes it very hard to even the most advanced sensors to distinguish it from the magnetic disturbance created by a cloaking device.
!ZN_PlanetarySystem
.20