JS

i usually have the window and door closed... when i get out of my room i have to do some effort to close the door (e.g. pushing a bit). (and for close it when i come back)... if i open the window the door is easy to close. i think that it should be a "decompressing" of the room of some like that... i don't know if it has more pressure after i open the window or before... my guess is that there are more pressure when is all closed because i use t-shirt all time inside the room and i don't use any sort of heat-device (and here is winter)... i mean... using P=nkT/V (V is constant)... but i'm not sure...

:S how do you get that H(x,y)?

in 1) set your (0,0,0) in the proyection of the point in the plane. given a line over (0,0,0) using that point we have a parabola , "rotating" the line over the plane we have more parabolas by simetry we have there a paraboloid that satisfies the condition of equidistance... i think that for visualize the others may be useful think about planes that intersect the lines and planes in case 2) & 3)... trying to get a point and a line over the cut-plane having a parabola over it

the application is about circuit and the incidence matrix seems to have information about capacitances, resistances and inductances... the work i have to do is about stochastic equations in a mathematical model of a network , i have to study the math point of view (is in a math course and i study math)... but the problem is refered to circuits and networks and i don't know too much about that... but is important to understand the problem formulation, and what means the equations... the entire problem is in a .ps file... (in google) "Stochastic DAEs in Transient Noise Simulator"... but my problem is only related to the problem formulation...

anyone could tell me how it is and how it work (a transiente noise simulator)? (no too much specific) what is a incidence matrix in a network? (i only need to know the "technical" definitions)

that's true... my question is about the interpretation of have a "bigger" sigma-field it make sense word 'information' beacause the conditional expectation is write E(X|F) (F is the sigma field) (and that F in some problems is not "constant...")

probability & measure

Anyone could explain me in what sense the sigma field in a probability space are related with the information that we have (any example?) (i have listen about: sigma field with more sets could be interpretated like we have more information, but I don't understand the idea yet) P.S: obviously my english is very bad

that's not a problem... tell your best friend you slept with her wife... that's a problem

A possible solution maybe do y1(x)=y(x) , y2(x)=y'(x) and the problem is now Y'=T(Y), T: R^2-> R^2 (obviously nonlinear) then use the euler method Yn+1=Yn+T(Yn)·DX Other way... but I don't believe that it work in thisproblem is use Raleigh-Ritz but I have use that method in problems y''+f(x)y'+g(x)=0 that isn't the case... Other way is read about Galerkin method but that is more related to PDE.

maybe in the analysis we should consider the probability of a person to be a possible 'attacker'... the extreme case: a war

But that 'feeling of safety' (given by postattack-ultrasecurity) make the security function decrease rapidly. I think that terrorist attack make a place 'locally' more safety (in a epsilon-interval of time)

take [0,L] == the bus, and suposse that you are sit in x=x0. the expectation of injury in that place is int_0^L D(x,x0)P(x) dx... P(x) is the pdf of the bomber-location (uniform by hipotesis) then E(x0)=1/L int_0^L D(x,x0) dx. D_x0 > 0 if x0<x and D_x0 < 0 if x0 >x then by simmetry E'(x0) = 0 when x0 is in the middle but in that case E(x0) is maximized. in fact, D_x0x0 is always negative because its more dangerous if x0->x Then, the solution its seem to be x0 =0 & x0=L