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KH.n;aHHe KBa.n;paTa OTKJIOHeHHH 3TOH CJIyqaHHOH BeJIHqHHbI OT ee cpe.n;Hero 3HaqeHHH:
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:t
D(X)
=M
[(X - X)2]
l
(x - X)2 p(x),
X
-ueJIOqHCJIeHHaH;
= x;,o
f(x -
X)2 f(x) dx, X -
HenpepbIBHaH.
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,LJ:HcnepcHH CJIyqaHHoH BeJIHqHHbI X xapaKTepH3yeT pacceHHHe 3TOH CJIyqaHHoH BeJIHqHHbI OTHOCHTeJIbHO ee cpe.n;Hero 3Haqe HHHX. ,LJ:HcnepcHH CYMMbI HeKOppeJIHpOBaHHhIX CJIyqaHHbIX BeJIHqHH paBHa CYMMe ,l{HcnepCHH CJIyqaHHbIX CJIaraeMhIX:
D(ixk) = iD(Xk ). k.1
k.1
12 13
CpeaHee ICeoapomu"teclwe (cmOHaOpmHoe) omICAOHe Hue CJIyqaHHOH BeJIH'IHHbI X - 3TO rrOJIO)I(HTeJIbHOe 3HaqeHHe
I(x)
KBa,n;paTHoro KOpHH H3 ;:{HCrrepCHH 3TOH CJIyqaHHoH BeJIHqHHbI:
cr(X) == cr x CpeaUHHoe CJIyqaHHOH
~eJIeHHe,
(eepORmHoe)
omICAOHeHue
HerrpepbIBHOH CHMMeTpHqHOe pacrrpe E, y~OBJIeTBOpHIOmee yCJIOBHIO =P(lx-xo.sl>E)=0.5 (pHC. 1.8).
x;
BeJIHqHHbI 3TO qHCJIO
P(IX-xo.sl<E)
=.jD(X).
HMeIOmeH
o F(x) 1.0
xp
x
1------------------ _;.;::-
I(x) p
o PHC.
x
1.8. Cpe~HHHoe
(BepoHTHoe) OTKJIOHeHHe
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x
= cr x X
HJIH
vx=~.100%.
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0 (x). IIpH 3TOM HCKOMble 3Ha qeHHH lPYHKUHH pacnpe.lleJIeHHH F(x;m,a) H ITJIOTHOCTH BepOHTHO CTH f(x; m, a) JIOrnOpMaJIbHOrO pacnpe.lleJIeHHH C napaMeTPaMH m, a onpe.lleJIHIOTCH no lPopMYJIaM H
f(x;m,a)
=ax1
0(h»), m4 ==a 4 (3+6h 2+h 4 )
Ha1faJThHble MOMeHTbI
J
a~m;
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(X _m)2 +
20 2
r, -
~
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o(h)
)l,HcrrepcIDI
cnY'lAAHOA BEnM'IMHbI
(OTPAJlCEHHOE HOPMAI1bHOE PACnPEAEnEHME)
f(x) == _ I
O'2
x == mr" a {
Mo.n:a
3.22. PACnPEAEnEHME MOAVnSl HOPMAI1bHOA
IInOTHOCTb BepOHTHOCTH
J
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o
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Me.n:HaHa X O.5 HBAAeTCH KopHeM ypaBHeHHjJ
Me.n:HaHa
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o (h) KBaHTHJIb x p
rroP(~:a_PmH)BJIjJeTC(::;;e)M <1>0 - - +<1>0
o
a
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orrHCbIBaeT pacrrpe.n:eJIeHHe cnyqaHHolf BeJIJRHHbI X == IYI, r.n:e Y X(t) == [ <1> { ; + iat <1> { ; - iat) e+ CJIyqalfHaH BeJIJRHHa, pacITpe.n:eJIeHHaH ITO HOpMaJIbHOMy 3aKOHY C
MaTeMaTH1feCKHM mKH,naHHeM m H CTaHJl:apTHbIM OTKJIOHeHHeM a.
llm
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a t + cos (mt) ] exp ( --2 MaTeMaTH1feCKOe O~aHHe
x = 20[ ~ exp(-
)
;::)+: ~.(:)]
O~eHHBSHMe
CHalfaJIa rryreM pellIeHHjJ ypaBHeHHjJ
=
= 2a[
o(h)], me
o(h'W (X')2
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(1)
orrpe.n:eAAeTcH oueHKa h' OTHOmeHHjJ h == m/a. 3aTeM rro l}>opMYJIaM
I
.
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H
m'==o'h'
m H a. 195
[(x)
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0.6
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,[{mI rrpH6JIIDKeHHOrO perneHIDI ypaBHeHIDI rrOJIb30BaHa Ta6JI. 3.4.
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5 x
(1)
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4
5
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1.0
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o 3.36.
h
'V(h)
h
'V(h)
h
'V(h)
h
'V(h)
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2
1/(27t) 0.159158 0.159195 0.1593 0.1597 0.1604 0.1615 0.1630 0.1650 0.1674 0.1701 0.1732 0.1764
1.3 1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 2.5
0.1798 0.1833 0.1869 0.1904 0.1938 0.1971 0.2004 0.2034 0.2063 0.2090 0.2116 0.2140 0.2162
2.6 2.7 2.8 2.9 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8
0.2183 0.2202 0.2220 0.2236 0.2251 0.2265 0.2278 0.2290 0.2301 0.2311 0.2321 0.2330 0.2338
3.9 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5
0.2346 0.2353 0.2382 0.2404 0.2420 0.2432 0.2442 0.2450 0.2456 0.2462 0.2476 1/4
co
B Ta6JIHue \jf(h) = [
o (h)]2 / (l + h2).
0.5
PRC.
3.4
...
...... --- ...... [(x)
...
I
... ...
... ...
reHepMpoa8HMe cny'l8MHblX '1MCen
.........
--
234
5
X
IInOTHOCTh BepOllTHOCTH R
cJIY'laJblOtI: BeJIH'IRHLl.
x
= 1m +
au
I HJlH
X
= 1m +
a(t,r, -6) I,
r,n;e U - CJIY'laHHOe qHCJIO cTaH,n;apTHoH HOpMaJIbHOH TeJIbHOCTH.
rrOCJIe,n;OBa
196 197
Ta6nMlIbi IIpH BbItiHCJIeHIDIX MOryr 6bITb HCrrOJIb30BaHbI Ta6JIHU;bI CTaH )J,apTHOrO HOpMaJIbHOro pacrrpe)J,eJIeHHH H Ta6JIHU;bI
,I
TeXHMKa BbI~McneHMM IlJIOTHOCTb BepOHTHOCTH f(x) OTpaJICeHHOrO HOpMaJIbHOrO pac rrpe)J,eJIeHHH CBj13aHa C IIJIOTHOCTbIO BepOHTHOCTH cp(x) CTaH,ZJ;apTHo ", ro HOpMaJIbHOrO pacrrpe)J,eJIeHHH COOTHOIIIeHHeM
1[
f(x) =~ cp (x-m) -a- +cp (x+m)] -a- . II p H M e 'I a H H e. B rrpHJIOXeHHHX )J,OBOJIbHO IIIHpOKO HCrrOJIb 3yeTcH OTpaJICeHHOe HOpMaJIbHOe pacrrpe)J,eJIeHHe C rrapaMeTpOM rrOJIOXeHHH m = O. HHJKe rrpHBO,WITCH OCHOBHbIe xapaKTepHCTHKH 3Toro BapHaHTa paccMaTpHBaeMoro pacrrpe)J,eJIeHHH.
(x2a
2
) 2 f(x) = --exp -2
IlJIOTHOCTb. BepoHTHoCTH
aili
2 = -cp
a
v"
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