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Submitted on 19 May 2006
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Perturbation Analysis of a Variable M/M/1 Queue: A Probabilistic Approach
Nelson Antunes, Christine Fricker, Fabrice Guillemin, Philippe Robert
To cite this version:
Nelson Antunes, Christine Fricker, Fabrice Guillemin, Philippe Robert. Perturbation Analysis of a Variable M/M/1 Queue: A Probabilistic Approach. [Research Report] RR-5419, INRIA. 2005, pp.26.
�inria-00070587�
ISRN INRIA/RR--5419--FR+ENG
a p p o r t
d e r e c h e r c h e
Thème COM
INSTITUT NATIONAL DE RECHERCHE EN INFORMATIQUE ET EN AUTOMATIQUE
Perturbation Analysis of a Variable M / M / 1 Queue:
A Probabilistic Approach
Nelson Antunes — Christine Fricker — Fabrice Guillemin — Philippe Robert
N° 5419
Deembre 2004
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x]Himp[ ki«tx]b[rinpiim]Hrqej]Hnkr o=q[°³ejou\]tuimrn]E]E\]Eq3kvi¨ou¢)kmY]
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® p[]Hp[]btuxm]xm]7nEtu ]HVr q Ã|~[~P]Eqjr £ï°&
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L(t)
j]Hq[ok]Hi¨kmY[]bqhp[\P]Exou¢npilkmo=\B]Hxi«tLk«kmr\]t
r qtqM/M/1
® p[]Hp[]§&r kmYtxxmrLt[xvtLk]
λ
tuq¤im]Ex3rsn]&xvtLk]µ
°³XY[]}Ltxrst[]B
j]Hq[ok]HiWkmY[]|[p[xtkmrouqou¢t#[pimg_~P]Exrohilktuxlkr q_§&r kmYouq]npilkmo=\B]HxK+ ru]Hq
L(0) = 1
ªB = inf{s ≥ 0 : L(s) = 0}.
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λ < µ
Y[ous[iH°.XY[]&rqhLtxrtuq=k³jrsizkxmr[pjkr o=qo¢(L(t))
rsi=]Eo=\B]EkmxrnHt gjrilkmxr[pjkm]7M§&r kmYM~tuxtu\B]Ekm]Hx
ρ = λ/µ
°&º[o=xx ≥ 1
ª[kY[]Ltuxmrst[]B x
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[p[xtkmrouqbo¢[t[pimg|~P]Exrohilktuxlkr q[&§&r kmY
x
nEpilkmou\]HxiH°;G«gj]E²q[r kmrouq)ªB 1
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° G«gnEouqhu]Hq3kmrouq)ª rq¤kY[]b¢Ýou oL§&rq[B§&Y[]EqVkmY[]Ltxrst[]HiB
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tq
B 0 1
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B
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p]Ep[]j]Hq[ok]Hïªh¢Ýo=x}ilYouxmkHªjhge3¦FEp[]Ep]u°
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ξ ≥ 0
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j]Hq[ok]Hitw.o=riimouq~[xojn]7imib§&r kmYGrq3km]Hqilr kzgξ
tuqG¢Ýoux0 ≤ a < b
ªN ξ ([a, b])
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[a, b]
°;-ùqB~txmkmrsnp[stx7ªN λ
§&r x]E~xm]7il]Hq=k$kY[]}txxmrLtj~[xojn]7imi³tuqN µ
kmY[]&~xmojn]7imi$ou¢kY[]|im]ExhrnE]Hi.o¢PkmY[]be3¦Ep]Ep[]=°.XY[]&w$o=riilo=q~xmojn]7imim]Hi
N λ
tqN µ
§&rPP]tuiilp[\]7BkmoP]br q[]E~P]Eqj]Hq3k«o=q[]|ou¢)]HtunvYoukmY[]Hx«tuqrqj]H~]Hqj]Eq3k ou¢&kmY[]\ojjp[stLkmrq[±atx¥uoL~[xmojnE]Hii(X (t))
°XY]V~[xojn]Hii(L(t))
nHtq¯P]xm]H~[xm]7il]Hq3km]H¬t=ikY[]imoupjkr o=qou¢kmY]izkohnvYtuilkmrsnb[r0/9]Ex]Eq3kmrstï]
®
ptLkr o=q
dL(t)
= L(t) − L(t−) = N λ ([t, t + dt]) − {L(t−)>0} N µ ([t, t + dt])
= d N λ (t) − {L(t−)>0} d N µ (t),
¶z7¸§&Y]Ex]
L(t−)
rsi}kY[]_]¢àk#r \r kbou¢s → L(s)
tkt
°#º[o=x|kY[]_x]E~xm]7il]Hq=kvtLkr o=qMo¢®
p[]Ep]Erq[atuxm¥=oL
~xmojn]7imim]Hit=i&ilo= pjkr o=qi«o¢³izkojnvYtuilkmrsnjr0/9]Ex]Eq3krtuï]
®
ptLkr o=qiHª[il]H]{}ouP]Exmk 274J°
½W½ 7 ¹$j ½  ½ ½ -ùqkmY]#¢Ýou oL§&rq[ª[§¨]nEouqimrsj]Ex|tuq
M/M/1
® p[]Ep]§&rµkYtil]Hxmhrsn]xvtLk]³Ltxg3rq[&rqkmr\]¨tuit¢Ýp[qnkmrouqou¢jimou\]³~[xojn]7imi
(X(t))
ktu¥hr q[&Ltu p[]7i)rqilo=\]Wil~tun]=ª7[]Eq[oukm]Hhg
S
°V´±]¤tuiilp\B]kYtLk#kY[]¤~[xojn]7imi(X (t))
rsituq±]Hxm=ojjrnatuxm¥=oLM~[xohnE]HiiouqS
°XWgh~[rsnEtu guª kY[]izkvtLkm]im~tunE]_ou¢@kmY[]]Hq3hrxmo=q[\]Eq3kS
rsibt¤²q[r km]oux#nEoup[q3ktu[]_im]k§&Y[]Eq(X (t))
ritatx¥uoLaoh[p[tkm]7w$o=riilo=qwWxmojn]7imiV¶·aaMwWw¨¸#o=x
S = R
rqkmY[]¤nHtuim]o¢&tMjr=/Ppimrouq)ª¢Ýoux#rqilktqn]¤tq`xqilkm]Hr qj¦5}Y ]Hq3P]Hnv¥M~xmojn]7imiB¶·im]E]ºxmrsnv¥u]HxIO 24ݸ°XY[]rq3Ltuxmrstq3k\B]7tuimp[x]_ou¢WkmY]B~xmojn]7imi
(X(t))
ri¨j]Eqokm]7hgν
°³XY[]|atuxm¥=oLhrtuqq[ouktLkr o=qE x (·)
§&r x]¢Ý]Hx@ouq gkmo#kY[]}rq[rµkrtuilktkm]x
ou¢kY[]atx¥uoLB~[xohnE]Hii
(X (t))
ªhkmY[]Hxm]E¢Ýoux]E ν (·)
§&r9[]Eq[oukm]kmY[]b]£j~P]Hnk]HV¹tu p]§&Y[]Hq¤kY[]~xmojn]7imi(X(t))
ri&tk}]®
p[r r[xr p[\°
XY[]Ltxrtu[ ]
L e ε (t)
[]Eq[oukm]Hi@kmY[]qhp[\P]Ex¨o¢npizkou\]Exvi@tLk¨kmr\]t
r q¤kmY[]M/M/1
® p[]Ep]}§&rµkY kr \]E¦JLtxghr qil]Hxmhrsn]xtkm]u°$XY[]~[xmojnE]Hii( L e ε (t), X(t))
rsitatuxm¥=oL~[xojn]7imiH°.XY]|kxtuqilr kmrouqi@o¢kY[]#~[xojn]Hii
( L e ε (t))
tuxm]buru]Hqhg+ -Õ¢L e ε (t) = l
tqX (t) = x
tLk&kr \]t
ªl →
( l + 1
tLk&xvtLkm]λ
l − 1 00 (µ + εp(x)) {l>0}
¢Ýo=ximou\]¢Ýp[qnkmrouq
p(x)
ouqkY[]ilktkm]_im~t=n]#o¢³kY[]]Hq3hrxmo=q[\]Eq3kS
tuqMimou\]im\tu ~txvt\]Ekm]Exε ≥ 0
°M´áY[]Hqp(x) > 0
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ªhkmY[]im]Exu]Hxri§&r kmYMtiloL§«]Exxtkm]kYtq r q¬kY[]eh¦Ep[]Hp[]u°±XY[]
®
ptuq3kmr kzg
p + (a)
¶·xm]7il~P]Hnkmru]Egp − (a)
¸rsiBj]²q]H¯t=imax(p(a), 0)
¶·xm]7il~P]Hnkmru]H g
max(0, −p(a))
¸°¨Ã«k}kr \]t ≥ 0
ªjkY[]tu[[rµkr o=qtnHt~t=nr kzg¤rsikmY[]Hxm]E¢Ýoux]εp + (X(t))
tuq
−εp − (X(t))
rsikmY[]nHt~t=nr kzg o3izk7°
XY[]bLtxrtu[]
B e ε
rsi¨kmY[]bjp[xvtLkr o=q¤o¢t[pimg~]Hxmroj¤izkvtxmkmrq[§&r kmYtnpizkou\]Ex7ªukYtLkrsiEªhuru]HqL e ε (0) = 1
ªB e ε = inf{s ≥ 0 : L e ε (s) = 0}.
ºoux
x ≥ 1
ªhkmY[]Ltxrst[]B e x ε
j]Eqokm]7i¨kmY[]#jp[xvtLkr o=qVou¢.t_[pimg¤~]Hxmrojilktuxlkr q_§&r kmYx
npilkmo=\B]Hxi¶
e B ε 1
= B e ε
¸° -ùqkmY[]#x]Hilk&o¢kY[rsi&~t~P]Ex7ª[§«]\tu¥u]kmY[]kz§«oB¢Ýou oL§&rq[tuiimp[\~jkmrouqiK+kY[]¢Ýp[qnkmrouq
|p(x)|
rsi&o=p[qj]73gtBnEouqilktuq3kM > 0
¶H 1
¸
ε sup(|p(x)| : x ∈ S) < µ.
¶H 2
¸
e3kvtqtxv¬txup[\]Eq3kviEª.il]H]VaM]Eghq¯tuq¬X§«]E]7jr]L2 4Jª³imY[oL§ kmYtk
( L e ε (t), X(t))
ri_tq¬]Hxm=oh[rn aGtx¥uoLw@xohnE]Hii§&Y[]Eqλ < µ
tuqε
ri|ilpj©¤nEr ]Hq=k gil\t)imo_kYtLk&kY[]#x]EstLkmrouqλ < µ
1 + ε Z
S
p − (x) ν(dx)
rsiitLkmrsil²]Hï° 5}q[]ExkmY]nouqjrµkr o=q
ρ = λ/µ < 1
ª@kmYrinEouqjr kmrouq §&r &P]imtkmrsiz²]H¯~xmoLhrsj]HkYtLk
ε
riilpj©¤nEr ]Hq=k gMim\t5°bXY[]®
p[]Hp[]§&r kmYMkr \]E¦JLtxghr qVil]Hxmhrsn]xvtLk]tuij]²q[]HtuoL=]§&r
P]xm]E¢Ý]Exxm]7MkotuikmY[]~P]Exmkmpxmtkm]7
®
p[]Hp[]uª[]Eq[oukm]H)ª)¢Ýoux#imY[ouxmkHª3gGw³¦Ep]Ep[]=°XY]nHtuim]
ε = 0
o=h3roupilg¤no=xmx]Him~o=q[iWkmokY[]e3¦FEp[]Ep[]=°
- +,+ %(5"!(,+ &%( 4,"# &2 /
XY]Wt=ilrsn³rsj]Ht&ou¢jkmY[]«~P]Exmkmp[xtLkr o=qtqtu gjimrinEtxxr ]7oupjk.r q#kY[rsi~tu~]Hxrsi)konEouqilkmxpnk.t|no=p[~[r q
ou¢WkY[][pimgG~P]Exr oj[iou¢¨kY[]~[xojn]Hiim]Hi
(L(t))
tuq( L e ε (t))
°VXY[rsiri[ouq[]tuib¢Ýo= oL§}iHª)~[xoL3rsj]7kYtLk&¢Ýo=x&oukmY
®
p[]Ep]Hi«kmY]txxmrLt9~[xohnE]Hii«ri
N λ
°Â. ·Á ³Â ½ j¹ ½ ´±]j]Hq[ok]|hg
N +
kmY[]q[ouqj¦ÕY[o=\Bo=u]Hq[]Eo=pi$w$oursimimouq~[xojn]Hii@§&Yo=im]rq3km]Hqilr kzgVrsi}=r =]Eqhg
t → εp + (X (t))
°|^¨ouqjr kmrouqt gouq(X(t))
ªkY[]qhp[\P]Exo¢³~Pourq=kvi}ou¢N +
rqkmY[]#rq3km]HxmLt
[a, b]
ª0 ≤ a ≤ b
rsiw$oursimimouq§&r kmY~txvt\]Ekm]Exε Z b
a
p + (X(s)) ds.
XY]V~Pourq=kviou¢
N +
tx]Vj]Eqokm]7¬hg0 < t + 1 ≤ t + 2 ≤ · · · ≤ t + n · · ·
tq¯tuxm]¤nHt ]7¯tujrµkr o=qt[]E~tuxlkp[xm]7iE°>-ùq~txmkmrsnptuxWkY[]jrsizkxmr[pjkr o=qou¢kmY]# ojnEtkmrouq
t + 1
ou¢kmY]²xilk&~o=r q3k}o¢N +
t¢àkm]Hx0
rsiuru]Hqhg=ªh¢Ýoux
≥ 0
ªP(t + 1 ≥ x) = P(N + ([0, x]) = 0) = E
exp
−ε Z x
0
p + (X(s)) ds
.
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ilkmojnvYt=izkrnw$oursimimouq~[xojn]Hiim]HiH°
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M/M/1
& ''½ Á ½ j¹ ½ ´]V[]Eq[oukm]¤hg
N −
kmY[]¤~Pourq3k_~[xojn]7imio=jktur q[]7hg '# ¤kmY[]~Pourq3k«~xmojn]7imi
N µ
¶5eh]H]b{}ouP]Exmk 27 4ݸ° -Õkrsi«[]²q[]7t=i@¢Ýo= oL§}iK+.Ã"~Pourq=k&tLks > 0
ou¢kmY]w$oursiilo=q~xmojn]7imi
N µ
ri«t~Pourq3k«ou¢N −
§&r kmY~[xmo=tr rµkzgεp − (X(s))/µ
° -ùq¤kY[ri«§t¹guªN −
ri«t_ilktkmrouqtuxmg~Pourq3k|~[xojn]Hii&§&r kmYrq3km]Hqilr kzg
εp − (X(s))
°}Ã~o=r q3k|ou¢N −
rsi|nEtu ]HMt¤\tuxm¥=]Hj]H~txmkmp[x]u°&XY[]~Pourq3kiou¢
N −
tx]j]Eq[oukm]7hg0 < t − 1 ≤ t − 2 ≤ · · · ≤ t − n ≤ · · ·
°@ºouxx > 0
ªjhgVj]E²q[r kmrouq)ªP(t − 1 ≥ x) = E
N µ ([0,x])
Y
i=1
1 − εp − (X (s i )) µ
,
¶(=¸§&Y]Ex]
(s i )
tuxm]kmY[]#~Pourq3ki&ou¢kY[]#~o=r q3k}~[xojn]7imiN µ
°
´ár kmYkmY]tPoLu]bq[okvtLkmrouqªjrµk}rsiq[ok}jr ©¤np[ k&kmoimY[oL§kYtLkkY[]atx¥uoL~[xojn]7imi
(e L ε (t))
YtuikY[]it\]#jrilkmxr[pjkmrouqtui«kY[]imoupjkmrouqo¢.kmY[]ilkmojnvYt=izkrnbjr=/P]Hxm]Hq3kmrst)]
®
ptLkmrouq
de L ε (t) = d N λ (t) − {e L ε (t−)>0} d N µ + N + − N −
(t),
¶·3¸§&YrnvYri&kmY[]tuqtou=p[]ou¢Ä
®
ptkmrouq¬¶z7¸¨¢ÝouxkmY]#w³¦Ep]Ep[]=°
)f,±. «' .) #¡.
]kpi#tuiimp[\]kYtLk#t[pimgM~]Hxmroj§&r kmY±ouq[]npizkou\]ExizkvtxmkitLkbkmr\]
0
rqGkY[]¤e3¦FEp[]Ep[]tqw@¦Ep[]Hp[]u°1-ùqkY[riil]7nkr o=q)ª§«]j]Ekm]Ex\r q]#kmY[]²xilk}k]Ex\ou¢.kY[]~PoL§¨]Hx|im]Exr ]7i&]£j~tuqilrouqrq
ε
ou¢kY[]]E£h~P]Hnkm]7¹tu p]#o¢
B e ε
ªkmY[][p[xtkmrouqo¢$kY[][pimgV~P]ExrohrqkmY[]w³¦Ep]Ep[]=°«XY[rsi|[]Exr LtLkr o=q tu oL§}i$piWr qVt=[jr kmrouqBkmot¹gBjoL§&q~txmk@o¢9kY[]|\tLk]Exrtu[q[]H]Hj]7r qkY[]}q[]E£3k«il]7nkmrouqkono=\~[pjkm]kY[]#\oux]rq3kmxrnHtLk]im]HnEouqVkm]Hxm\o¢kmY[]#~PoL§¨]Hx}il]Hxmr]Hi«]E£h~tqimr o=qrq
ε
°ºouxkmY]²xilk«o=x[]Ex«km]Hxm\ªj§«]o=q[ gVYt¹u]|kmono=qilrsj]Hx¨kY[]#nEt=il]7i¨§&Y]EqkmY[]Hxm]rsi¨]HrµkY[]Ex}timr qu]
t=[jr kmrouqtu@j]E~txmkmp[x]oux#]Esim]¤tMilrq[u]\tx¥u]H±j]H~txmkmp[x]u°¤XY]~[xmo=tr rµkzgkmYtkoukmY¬]E=]Eq3ki
ojnHnp[x«r q¤kmY[]imtu\]|[pimg~]Hxmroj¤rsi¨nE ]7tx gou¢ïkmY[]bouxvj]Ex¨o¢)\t=q[r kmpj]bo¢
ε 2
ilrqnE]}kmY]rq3km]Eqilr kmr]Hi ou¢kY[]tuiilojnErtkm]HVw$oursimimouq~[xohnE]Hiil]7itx]~[xou~PouxmkmrouqtPkmoε
°ºoux
x ≥ 1
ª)kmY[]ilktr rµkzgt=imimp[\~jkr o=qib]Eqimp[x]kYtLkkmY]B]E£j~]7nkm]7GLtu p[]7ibo¢WkY[][pimgM~]Hxmr ¦ oj[i#ilktuxlkr q§&r kmYx
nEpilkmou\]HxiHª)qtu\B]H gE(B x )
tuqE( B e x ε )
ª$tx]BoukmY²q[r km]=°¤´áY[]HqkY[]²xvizk t=[jr kmrouqtu)tq\tx¥u]7Vj]H~txmkmp[x]Hi&tuxm]impnvYkmYtkt + 1 > B e ε
tqt − 1 > B e ε
kY[]EqB = B e ε
°-ùqMt_²xvizk|ilkm]H~)ªj§¨]~[xoLu]kmY]¢Ýou oL§&rq[Bkm]7nvY[q[rsnEtï]E\\t[°
¨½ ¯ C '#
K
Oε 0 > 0
N'#ε < ε 0
n ≥ 1
sup
x∈S E
B e n ε | X (0) = x
≤ Kn.
1KF -Õ¢$ouq]nvYo3o3il]7i
ε 0
imoBkmYtk
µ 0
= µ − ε 0 inf{p − (x) : x ∈ S} > λ,
kY[]EqnE ]7tx gVkmY[]q3p\P]Ex|ou¢@npilkmo=\B]Hxi}o¢$kmY[]w³¦Ep]Ep[]rsi|nE]Exmktur q[gim\t ]Hx&kmYtqkmY]qhp[\P]Ex
ou¢}npilkmo=\B]Hxio¢|tq
M/M/1
® p[]Ep[]§&rµkY¯txxmrLt@xvtLk]λ
tq¬im]ExhrnE]xtkm]µ 0
°±^¨o=qil]
®
p[]Eq3kmguª
kY[]nouxx]Him~o=qjrq[[pimgM~]Hxmroj[ibnou\~tuxm]r qGkmY[]imtu\]§t¹guªPY[]EqnE]r kbrsib]Eq[o=p[uYkmo¤kvt¥=]
K = 1/(µ 0 − λ)
°ru]HqkY[]tPoLu]km]7nvY[q[rsnEtuï ]H\B\tªj§¨]#q[oL§"no=qilrsj]Hx¨kY[]jr=/P]Hxm]Hq3k}~o3imimr r rµkr ]7iE°
+ ½ [ÂÂ Ý Á ¨Â ½ j¹ ½
-Õ¢WkmY[]Hxm]Bribo=q[ go=q[]Bt=[jr kmrouqtu.[]E~tuxlkp[xm]BtqGq[o\tuxm¥=]HMj]H~txmkmpxm]_r q
(0, B e ε )
kmY]EqtLk|kr \]B e ε
ªjkmY]#w³¦®
p[]Hp[]#rsi]E\~jkzgtuq
®
p]Ep[]
L
rsi§&rµkYo=q[]npizkou\]Ex#¶·im]E]º.rup[x]H¸°6
- 6
e B B ε t + 1
0 1
w³¦FEp[]Ep[]
e3¦FEp[]Ep[]
º.rup[x] +³Ã([pimgVw$]HxmrojV§&r kmYMtqÃ&[jr kmrouqt]E~tuxlkp[x]
´±]il~P]HnErµ²PnEtg¤~[xoLu]kmY[]¢Ýo= oL§&r qB]E\\t[°
¨½ ¯ L' < = CO
C
E
(B − B e ε ) {t +
1 <B}
= ε E ν [p(X (0)) + ]
(µ − λ) 2 + o(ε),
¶Ju¸
'
ν
3C< # 83C K O I#(X (t))
1KF }´áY]EqkmY]Ex]#ri&o=q[gVouq]tu[jr kmrouqt)j]H~txmkmp[x]uª[kmY[]Ltuxmrst[]
B e ε
rsi&]Ekz§¨]H]Eqt + 1
tqt + 2
°´±]nEtuq§&xr km]
E
(B − B e ε ) {t +
1 <B}
= E
(B − B e ε ) {t +
1 < B e ε <t + 2 ,t − 1 > B e ε }
+ ∆,
¶5=¸§&Y]Ex]kY[]#oO/ïim]kkm]Hxm\
∆
nEtuqP]#Poup[q[]Htui«¢Ýo= oL§}i∆ ≤ E
|B − B e ε |
{t + 2 < B e ε ,t − 1 > B e ε } + {t −
1 ≤ B e ε ,t + 1 ≤ B e ε }
.
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& '' ]kpi¤]Hilkmr\tLk]MkmY[]G²xvizk¤k]Ex\ o¢kmY[]xmruY3km¦JYtuqilrsj]ou¢ ¶·=¸° Ä ®
ptLkr o=q¶5=¸tqkmY[]
Poupqj]H[q[]Hiio¢
p
uru]bkmYtkP(t + 1 ≤ B) = 1 − E exp −ε Z B
0
p + (X (s)) ds
!!
= εE Z B
0
p + (X (s)) ds
! + o(ε)
= εE(B) E ν
p + (X (0))
+ o(ε) = ε µ − λ E ν
p + (X (0)) + o(ε)
hgBr qj]E~P]Eq[]EqnE]ou¢
B
tqBkmY[]izkvtLkr o=qtxrµkzg_o¢(X(t))
° G«gBkmY]ilkmxouq[aGtx¥uoL~[xou~P]ExmkzgtLkWkY[]ilkmo=~[~[rq[Bkmr\]
B e ε
ªnouqjrµkr o=qtg¤ouqkmY]]E=]Eq3k{t + 1 < B e ε < t + 2 , B e ε < t − 1 }
ªjkmY[]eh¦Ep[]Hp[]ilktxmki tkB e ε
tqr qj]E~P]Eq[]Eq3k}[pimgV~P]Exr oj§&rµkYouq[]#npizkou\]Ex7ªhkmY[]Hxm]E¢Ýoux]E
(B − B e ε ) {t +
1 < B e ε <t + 2 ,t − 1 > B e ε }
= P(t + 1 < B e ε < t + 2 , t − 1 > B e ε )
× E
(B − B e ε ) | t + 1 < B e ε < t + 2 , t − 1 > B e ε
= P(t + 1 < B e ε < t + 2 , t − 1 > B e ε )E(B 1 ).
?|oL§#ª[ilrqnE]
{t + 1 < B e ε } = {t + 1 < B}
o=qVkY[]#]E=]Eq3k{t + 1 < B e ε < t + 2 , B e ε < t − 1 }
ªjkmY]EqP(t + 1 < B e ε < t + 2 , t − 1 > B e ε ) = P(t + 1 < B) − P(t + 1 < B e ε , t + 2 < B e ε )−
P(t + 1 < B e ε , t − 1 < B e ε ) + P(t + 1 < B e ε , t + 2 < B e ε , t + 1 < B e ε )
= P(t + 1 < B) + o(ε),
imrqn]&kz§«o#oux¨\oux]&]£hkmxvtyzp[\~i¨r qkY[]it\]}pilgB~P]Exr ojrsi
o(ε)
°³ejr \rtuxmguª=3gpimrq[t3trqkmY[]ilkmxouqBatuxm¥=oL~[xmo=~]Hxlkzg=ªjouq[]=]ki«kY[]¢ÝouoL§&r q[]7izkr \tLkr o=q
E
|B − B e ε | {t +
2 < B e ε ,t − 1 > B e ε }
≤ X
n≥2
E(B n )P(t + n ≤ B e ε ≤ t + n+1 , t − 1 ≥ B e ε )
≤ 1 (µ − λ)
X
n≥2
nP(N + ([0, B]) = n).
-ùqj]E]7ïªH=r =]EqbkmY]We3¦Ep]Ep[]=ª
N + ([0, B])
Yt=i)tw$oursimimouqjrsizkxmr[pjkr o=q#§&rµkY#~txvt\]k]ExR B
0 εp + (X (s)) ds
ª§&YrnvYr \~[r]HikYtLk
X
n≥2
nP(N + ([0, B]) = n) =
E Z B
0
εp + (X (s)) ds
!
− E Z B
0
εp + (X(u)) du e −ε R 0 B p + (X(s)) ds
!
= o(ε)
tuqkY[]}²xvilkWkm]Hxm\ rq¤kY[]|xr =Y3k¨Ytuq¤imrj]o¢ -ùq[]
®
ptrµkzg¶
¸@riWkmYhpi¨q[]E= rur[]tkWkmY]}²xvizk«ouxvj]Ex
rq
ε
°Xo]Hilkmr\tLk]&kmY[]bil]7no=q_km]Ex\ r qkY[]}xr =Y3kWYtqilrsj]}ou¢-ùq]
®
ptr kzg¶
¸ª=§«]}q[]H]HBkmo_nouqilrsj]Ex
kY[]¤jr=/P]Hxm]Hq3k~o3imimr r rµkr ]7i¢ÝouxkmY[]ojnEtLkr o=qou¢
t + 1
tqt − 1
° -ùq±kmY[]¤nHtuim]BkmYtkt + 1
tuqt − 1
ohnHnp[x[p[xmrq[
[0, B]
tuqB e ε ≥ B
ª$tLkkr \]B
kmY[]¤w@¦Ep[]Hp[]Yt=itLk_\Bo3izkp ≥ 0
npilkmo=\]Exvi#rµ¢kY[]Ex]Yt¹u]&P]E]Eq
p + 1
\tx¥u]7B[]E~tuxlkp[xm]7iE°>-Õ¢D([0, B])
rsi@kY[]|qhp[\_]HxWo¢)nEpizkou\]ExviW[p[xmrq[#kY[]|pilg~P]Exroho¢.kmY]e3¦Ep]Ep[]=ªhkmY[]HqnE]Exmktur q[g
E
( B e ε − B) { B e ε ≥B,t − 1 ≤B,t + 1 ≤B}
≤ E E X(B) B D([0,B])
P(t − 1 < B, t + 1 ≤ B ≤ t + 2 )
≤ KE (D([0, B])) P(t − 1 < B, t + 1 ≤ B ≤ t + 2 ) = o(ε),
hg ]E\\tu°¨`qkmY[]#oukmY[]Hx&Ytq)ª
E e B ε − B { B e ε <B,t − 1 ≤B,t + 1 ≤B}
≤ E B {t −
1 ≤B,t + 1 ≤B}
= o(ε).
º.rqtguª
E e B ε − B
{t − 1 ≤ B e ε ,t + 1 ≤ B e ε }
≤ E e B ε − B
{t − 1 ≤B,t + 1 ≤B}
+ E
B {t −
1 ≤B,B≤t + 1 ≤ B e ε }
,
§&Y]Ex]#rµknHtqP]ilYoL§&qrqtimr \rtux}§«t¹gtui&P]¢Ýo=xm]kYtLk|kmY[]stuilk&km]Hxm\-rsi
o(ε)
°|`q[]nEouqnE pj]Hi kYtLkVkmY[]Gkm]Ex\∆
rsio(ε)
tuiε
=o3]7ikmo0
° G«gpilrq[¯Ä®
ptLkmrouq ¶53¸ª}§«]ou[ktrqkmY]j]7ilrxm]7
x]Himp[ kH°
XY[]]7izkr \tkmrouqo¢«kmY[]VxmruY3k#Ytq±imrsj]o¢Ä
®
ptLkr o=qá¶·=¸b\t¹gGtu~[~P]Htx
®
prµk]¤np[\_]Hximou\]u°
-Õk}rsiY[oL§«]E=]Ex«§¨o=xlkYq[oukmrq[BkmYtk&kmY[]#]Hqh3rxouq[\]Eq3k
(X (t))
o¢kmY[]#w@¦Ep[]Hp[]r q3kxmojjpnE]Hi&j]H rsnEtkm][]E~P]Eqj]Hqn]7iEªh§&Y[rsnvYVYt¹u]}koP]Ytqj]HV§&rµkYnHtx]u°$XY[rsi¨rsi¨§&Y3g=ªh§¨]bYt¹u]nvY[o=im]Eqko_]E£j~[ rsnr kmg
§&xr km]kmY]~[x]Hnrsim]il]Eklkmrq[¤rq§&Y[rsnvYkmY[]ilkmxouqaGtx¥uoL¤~[xou~P]Exmkzg¤rsi}pim]Hko¤u]Ek&kmY[]#²xilk}ouxvj]Ex
k]Ex\° -ùqVkY[]¢Ýou oL§&rq[ª[ilr\r stx}tuxm=p[\]Eq3ki«§&r ïq[ouk}]#]E£j~[ rsnr kmg¤¢Ýo=xm\_p[stLkm]7ï°
+ ½ ¯j ½ ÂÂ ½ j¹ ½
ejp[~[~Po=im]BqoL§ kmYtLk#kmY]Ex]Brsi#o=q[ gGouq[]\tx¥u]7Gj]H~txmkmp[x]uªr5°]u°¤tj]H~txmkmp[x]o¢¨kmY[]Ve3¦FEp[]Hp[]ri
nHtqnE]E]HV¢ÝouxkY[]w³¦Ep]Ep[]=ªtqq[otujrµkr o=qthyzp\B~i}jp[xr q_kY[]#[pimg¤~P]Exr ojo¢.kmY[]e3¦FEp[]Hp[]u°
-ùq kmY[rsinEt=il]=ª@tLkkmY]]Hq ou¢}kmY]pilg¬~P]Exroh o¢}kY[]e3¦FEp[]Ep[]=ªWtLkBkmr\]
B
ª@kY[]w³¦® p[]Hp[]Ytui o=q[]nEpizkou\]ExbtqkYhpi|ilktuxlkvi|t[pilg~]Hxmrojï°}w@xoLhr[]HkmYtLk}kY[]Ex]_tuxm]#q[oV\Bo=xm]\tuxm¥=]Htqt=[jr kmrouqtuj]H~txmkmpxm]7iWjp[xrq[
(B, B e ε )
rq¤kY[]|w@¦Ep[]Hp[]}kY[]EqVkmY[]bjr=/P]Hxm]Hqn]]Ekz§¨]H]EqVPokY¤[pimg~P]ExrohiWYt=i@kY[]it\]bjrilkmxr[pjkmrouqtui@kmY[]b ]Hq[kY
B 1
ou¢tilktuq[txv[pimg~]Hxmrojï°@eh]E]º.r =p[x]JM[°
"!#$%
M/M/1
& '' u6
- 6
0 1
w³¦FEp[]Ep[]
t − 1 B
e3¦FEp[]Ep[]
B e ε
º.rup[x] +@Ã G«pimgVw$]Exr oj§&rµkYMtB]E]k]H]E~tuxlkp[xm]
¨½ ¯ L' < = O CO C
E
( B e ε − B) {t −
1 ≤B}
= ε E ν [p − (X (0))]
(µ − λ) 2 + o(ε).
¶M=¸1KF JG«g¤pilrq[BkmY[]it\]#txup\B]Hq3kituiP]¢Ýo=xm]=ª[ouq[]o=jktur qi«kY[]#x]EstLkmrouq
E
( B e ε − B) {t −
1 ≤B}
= E
B 1 {t − 1 ≤B, B+B 1 <min(t + 1 ,t − 2 )}
+ o(ε)
= E(B 1 )P(t − 1 ≤ B) + o(ε).
Xo]Hilkmr\tLkm]
P(t − 1 ≤ B)
ªx]HnEtu )kmYtk(D i )
j]Eqokm]kY[]im]®
p[]Hqn]#ou¢$j]H~txmkmpxm]7i«kmr\B]7i}rqkmY[]
S
¦Ep[]Hp[]tqN
kmY[]_qhp[\P]Exo¢Wnpizkou\]Exvi}im]Exu]Hjpxmrq[kY[][pilg~P]Exr ojo¢@]EqkmYB
ªkY[]EqÄ ®
ptLkmrouq¶(3¸«uru]7iWkY[]#rsj]Eq3kmr kzg
P(t − 1 ≤ B) = E
X N i=1
εp − (X (D i )) µ
i−1 Y
j=1
1 − εp − (X (D j )) µ
= ε µ E
X N i=1
p − (X (D i ))
! + o(ε)
= ε
µ E(N)E p − (X (D 1 )) + o(ε)
hgizkvtLkr o=qtxrµkzgo¢
(X(t))
tq´tsiº[o=xm\_p[st[°ehrqn]E(N ) = µ/(µ − λ)
¶·im]E]VÃ|~[~P]Eqjr £¸ª Ä ®ptLkmrouq¶M3¸¨¢Ýou oL§}iH°
-ùqkmY[]B]£j~tuqimr o=qo¢@kY[]B[pimgM~]Hxmrojo¢WkmY[]Bw³¦FEp[]Ep[]=ª9kmY[]_km]Hxm\»rq
ε
riuru]HqGhgkmY[]Bkz§«o ]Hu]Hq=kvinEouqimrsizkr q[r q_ouq[gouq[]«\tx¥u]7oux.ouq[gouq[]tu[[rµkr o=qthj]E~txmkmp[x]¨jpxmrq[}kY[]«[pimg#~]Hxmrojou¢
L
°@XY[]q[]£hk}~[xou~Po=imrµkr o=qV¢Ýo= oL§}i¨¢Ýxmo=\¡Ä®
ptkmrouqi¶J¸tq±¶Mu¸E°
Á WÁ · Á ÝLHLÂ ½ Á
E( B e ε ) = 1
µ − λ − ε E ν [p(X(0))]
(µ − λ) 2 + o(ε).
¶5=¸Ä ®
ptkmrouq±¶·=¸Wrsi«nEouqimrsizk]Eq3k¨§&r kmYkmY[]imo¦ùnEt]H{&]7jpn]7eh]Hxmhrsn]b{}tLk]btu~[~[xo¹£hr\tLkr o=q)°Ãi«t
\tklkm]Hx}o¢.¢·tunkHª]Eu]Hxmg3kY[r qBYt~[~P]Eqi|tui&r ¢³§¨]#Yt=tnstuiilrsnEtu
M/M/1
® p[]Ep[]§&rµkYim]ExhrnE]#xtkm]µ + εE ν [p(X (0))]
tqGtxxmrLt)xvtLk]λ
°-ùqMkYtLk®
p[]Ep[]=ªPkmY[]B\]HtqM]EqkmYo¢³kY[][pilg~P]Exr ojMrsi
=r =]Eq3g
1
µ + εE ν [p(X (0))] − λ = 1
µ − λ − ε E ν [p(X (0))]
(µ − λ) 2 + o(ε),
§&YrnvYVnEourqnrsj]7iW§&r kmY¤Ä
®
ptLkmrouq±¶·u¸E° -ùqkmY]|¢Ýo= oL§&r qil]7nkr o=q)ª=§«]|rqhu]7izkr 3tLkm]}kmY[]il]7no=qouxvj]Ex
k]Ex\ tqimY[oL§ákYtLk&kY[]{|ej{(tu~[~[xo¹£hr\tLkr o=qVrsiq[o\Bo=xm]Ltrsï°
) $ '&*« # ¡
-ùq_kmYri@im]Hnkmrouq)ªkmY[]&noh]E©nEr ]Hq3k$ou¢
ε 2
o¢kmY[]&\]7tqB[pimg~]HxmrojE( B e ε )
rsi³nEtunEp[stLkm]7ï°;-ùqBkY[]}imtu\]§t¹gtui«¢Ýo=x¨kY[]b²xvizk&ouxvj]HxHª=kmY[rsi&noh]E©nEr ]Hq3krsix]EstLkm]7ko_kY[]]E=]Eq3k¨kYtLkkz§«o_]E£hkmxvt}yzp[\~i}ohnHnp[x
[p[xmrq[Mt[pimg~P]Exr oj±o¢«kmY]~]Hxlkp[xmtLkm]7
M/M/1
® p]Ep[]=°ehrqn]]E£3kxt_yzp[\~inEtqP]]Er kmY[]Hx t=[jr kmrouqtuj]H~txmkmp[x]Hi}ouxnHtqnE]E]HMj]H~txmkmpxm]7i¶Ý\tx¥u]7j]E~tuxlkp[x]Hiv¸ª[kY[]Ex]tuxm]kY[xm]H]nEt=il]7ikmorqhu]7izkr 3tLkm]=°Ãi@r k¨§&r ]|im]E]Hq)ª=kmY[rsiWnEo3]E©¤nr]Eq3k¨ilkmx]Hiil]7i$kmY[]|r \~Pouxmktqn]}ou¢PkY[]}]Huoupjkr o=qo¢9kmY[]
Ltuxmghrq[nHt~t=nr kzguª9kY[xmo=p[uY±r ki#no=xmx]EstLkr o=qM¢Ýp[qnkmrouqrq~tuxlkrnEp[stx7°BXY[rsi§tuibq[ok#kY[]nEt=il]_¢Ýoux
kY[]²xvizk&o=xj]Hx«km]Ex\ªimr qnE]ouq[gkmY]t¹u]Exvt=]|Ltp[]o¢.kmY]nEt~tunr kzg¤imY[oL§}ip[~kmY[]Hxm]=°
-ùqákY[]¢Ýo= oL§&rq[ªrqouxvj]Ex¤kmo¯=]k¤kY[]
ε 2
nEo3]E©¤nr]Eq3kHª}o=q[]Yt=iko no=qilrsj]HxkmY[]±jr=/P]Hxm]Hq=k~Po=iimr [rrµkr ]7i«¢Ýoux&kY[]# ojnHtLkmrouqo¢.kmY]#¹tuxmrst ]7i
t + 1
ªt + 2
tuqt − 1
ªt − 2
° G«g¤pilrq[ilr\r stx}tuxm=p[\]Eq3ki t=i«r qeh]7nkmrouq([ªjr k}rsiq[ok}jr ©¤np[ k&kmoimY[oL§ákmYtLk|tqhg]Hu]Eq3k&rq3=ouhr q[t + 3
o=xt − 3
ghr]Es[i&t_km]Hxm\¡ou¢kY[]#ouxvj]Hx
ε 3
rqVkY[]#]£j~tuqimr o=qou¢E( B e ε − B)
°]²q]
A + = {t + 1 ≤ B, t − 1 ≥ t + 1 + B L(t +
1 )−1 }.
`q kmY[rsi]E=]Eq3kHª¨tj]H~txmkmpxm]rit=[j]H tq¬kmY]pilg ~]Hxmroj¯o¢kmY[]w³¦FEp[]Ep]²q[rimY[]7i_P]¢Ýo=xm]
tj]E~txmkmp[x]¤rsi_imp[~[~[x]Hiim]H¶·q[ok]¤kmYtLk
B L(t +
1 )−1
ri_kY[]V]Eq[ukmY o¢|tpilg~P]Exr oj¬ou¢be3¦FEp[]Ep]
ilktuxlkr qBtk&kmr\B]
t 1
§&r kmY
L(t + 1 ) − 1
nEpilkmou\]Hxiv¸°W`qkmY[]#]Hu]Eq3kA ± = {t − 1 ≤ B, B ≤ t + 1 ≤ B + B 1 },
tG\tx¥u]H j]E~tuxlkp[x]VojnEnEp[xiBtq tqokmY]Exj]E~tuxlkp[x]Vrsi_t=[j]H ]E¢Ýoux]VkY[]nou\~[]kr o=q ou¢}kmY[]
pilgG~]HxmrojGou¢WkmY]w³¦
®
p[]Hp[]uª§&Y[]Ex]
B 1
j]Hq[ok]HibkmY][p[xtkmrouq±o¢¨kmY[]tujrµkr o=qt³pilgG~]Hxmroj
[p[]kmoBkmY]ilp[~~[xm]7imim]Hj]H~txmkmp[x]u°$º.r qt g=ª[ouqkmY[]#]Hu]Hq=k
A − = {t − 1 ≤ B, B + B 1 ≤ t + 1 },
tkb]Ht=izkt\tx¥u]HGj]E~tuxlkp[x]_ojnEnEp[xvibtuqqo[]E~tuxlkp[xm]7ituxm]tuj]HG]E¢Ýoux]_kY[]no=\B~ ]EkmrouqGou¢
kY[]#[pimg¤~P]Exr oj
B
°"!#$%
M/M/1
& '' K(G«g_nvY]Hnv¥hr qtu [kmY[]}jr=/9]Ex]Eq3kWnEt=il]7iEªr k@rsi³q[okW[rµ©¤npµk@koil]H]kmYtk@rµ¢
A = A + ∪ A ± ∪ A −
ª=kmY[]]E£j~[xm]7imimrouq
E(( B e ε − B) A c )
rio(ε 2 )
¶5tqG]Eu]Hq]®
ptukoVr q±ilo=\B]BnEt=il]7iEª¢Ýouxbr qizkvtqnE]§&Y[]Hq
kY[]Ex]|tuxm]}t\tx¥u]7j]E~tuxlkp[x]}tqtuqt=[jr kmrouqtuj]H~txmkmpxm]&rq¤ilpnvY¤t§«t¹gkmYtk
B e ε = B
¸°³XY[]¢Ýo= oL§&rq[Bim]Hnkmrouqi&tuxm]#j]Huoukm]HVkmoBkY[]#]Hilkmr\tLkmrouqo¢
E(( B e ε − B) A )
¢Ýo=xA ∈ {A + , A ± , A − }
ª-ùqt²xilkilkm]H~)ªW§«]tqtu g DE]VkmY[]MnHtuim]§&Y[]Hq kY[]Ex]tx]Vouq g¯t=[jr kmrouqtu[]E~tuxlkp[xm]7iP]¢Ýo=xm]
B
ªWkYtLkriHª¨§«]Mno=qilrsj]HxkmY[]k]Ex\E(( B e ε − B) A + )
°´áY[]Hq qo±\tuxm¥=]H j]E~tuxlkp[x]ojnHnp[xviEª tkb\o3izkbkz§¨otu[[rµkr o=qt³j]H~txmkmp[x]Hi|r qkmY]kr \]r q3k]Ex¹tu[0, B]
ªïohnHnp[xxr q[tLkbkmr\]t + 1
tqt + 2
x]Him~P]Hnkr =]Eguªï\t¹gM~[st¹gtVxou]Br qkmY[]¤nEou\~[pjkvtLkr o=qGo¢¨kmY[]nEo3]E©¤nr]Eq3k#o¢
ε 2
o¢E(B − B e ε )
°<-ùqkY[rsibnHtuim]uªPkmY][r0/9]Ex]EqnE]_P]kz§«]E]Hq
B − B e ε
rib] ® ptu.kmokmY[]B[pimgM~]HxmrojGou¢¨tq±e3¦Ep]Ep[]B§&Y[rsnvY ilktuxlkvi@§&r kmY¤]HrµkY[]Ex¨ouq[]ouxWkz§¨onEpilkmou\]HxiHª=j]H~]Hqjrq[o=qkmY[]¢·tunk@kmYtLkHªho=qkmY[]]E=]Eq3k{t + 1 ≤ B}
ªkY[]#[pimg¤~P]Exr ojo¢kmY[]#w@¦Ep[]Hp[]ri|txm]7tujg¤nEou\~[]km]7tLkkmr\]
t + 2
o=x«qokH°Wej]E]º.r =p[x] ([°Ãi|P]¢Ýo=xm]=ª
B 2
[]Eq[oukm]Hibtxvtq[ou\-¹tuxmrst ]§&r kmYGkmY[]Bimtu\]_jrsizkxmr[pjkr o=qGtui}kmY[]imp[\o¢³kz§«o
rqj]H~]Hqj]Hq=k}Ltuxmrst[]Hijrsilkmxr [p[km]Ht=i
B 1
tuqVrqj]H~]Hqj]Hq=ko¢
B
ªt + 1
tqt + 2
°¨`q[]#u]EkiE
(B − B e ε ) A +
= E
(B − B e ε ) {t +
1 ≤B,t − 1 ≥t + 1 +B L(t + 1 )−1 }
= E (B 2 ) P
t + 1 < B, t + 2 < t + 1 + B L(t +
1 )−1 , t − 1 ≥ t + 1 + B L(t +
1 )−1
+ E (B 1 ) P
t + 1 < B, t + 2 ≥ t + 1 + B L(t +
1 )−1 , t − 1 ≥ t + 1 + B L(t +
1 )−1
+ o(ε 2 ).
XYri&j]7no=\B~Po=imr kmrouq]Eq3ktur si«kmYtk
E
(B − B e ε ) A +
= (E (B 2 ) − E (B 1 )) P
t + 1 < B, t + 2 < t + 1 + B L(t +
1 )−1
+ E (B 1 )
P t + 1 < B
− P
t + 1 < B, t − 1 ≤ t + 1 + B L(t +
1 )−1
+ o(ε 2 ).
¶lH=¸6
- 6
t + 1 B
e3¦FEp[]Ep[]
t + 2 B e ε
w³¦FEp[]Ep[]
ºrupxm]3(C+³X§¨oÃ&[[rµkr o=qt]E~txmkmp[x]Hi
ºxmo=\ Ä ®
ptkmrouqG¶lHu¸ª=o=q[]}Yt=i³ko]£j~tuqBkmYxm]H]}]£j~[x]Hiilrouqi³§&rµkYxm]7il~P]HnkWko
ε
°$XYriWri¨jouq[]hg¤~xmoLhrq[kY[]kmYxm]H]¢Ýo= oL§&rq[ ]H\B\t=iE°
¨½ ¯ C '#
P
t + 1 < B, t + 2 < t + 1 + B L(t +
1 )−1
8 < 'P
t + 1 < B, t + 2 < t + 1 + B L(t +
1 )−1
= ρε 2 E Z B
0
(B − v)E ν p + (X (0))p + (X(v)) !
dv + o(ε 2 ),
¶lu7¸1KF ]k@pi@xm]7nEtjkY[]&xm]Hu]Hq[]ExvtLkr =]«j]7imnExmr~jkr o=qBou¢9tpilg_~]Hxmrojizkvtxmkmrq[#tLk³kmr\]
0
§&r kmYouq[]nEpilkmou\]HxK+ëk#kmr\]
E 1
¶Ý]E£h~Pouq]Eq3kmrst gjrilkmxr[pjkm]7G§&r kmY~tuxtu\]km]Hx
λ + µ
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kmY[]&[pilg~P]Exroh_rsi$²q[rsilY]Hï°@`|kmY[]Hxm§&rsim]uª§&r kmYB~[xoutu[r r kzgλ/(λ+µ)
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B = E 0 + X H i=1
E i + B i 1
,
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ri=]Eo=\B]EkmxrnHt g jrilkmxr[pjkm]7§&rµkY~tuxtu\B]Ekm]Hxλ/(λ + µ)
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tx]Mr5°rJ°]E£h~Pouq]Eqj¦krtu gjrsizkxmr[pjk]HG§&rµkYG~tuxtu\B]Ekm]Hx
λ + µ
tq(B 1 i )
tuxm]_r5°rJ°ï°Ã| .kY[]Him]_xvtqjou\Ltxrtu[]Hibtx]rqj]H~]Hqj]Hq=k7°@º[o=x
0 ≤ i ≤ H
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s i
j]Eqokm]7i.kmY[]&]HqBo¢PkmY[]
i
kYimp[j¦Õ[pimgnEghnE ]$+s 0 = 0
tuqïªL¢Ýo=xi ≥ 1
ªs i = s i−1 +E i +B 1 i
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c
N i
j]Hq[ok]HikY[]qhp[\P]Ex}ou¢.tuxmxr Ltuijp[xrq[BkmY[]
i
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tx]kY[]#rqizkvtq3kiou¢.j]H~txmkmpxm]7io¢.nEpilkmou\]Hxi&jpxmrq[BkmY[]i
kYilpj¦Jpilgngjn]u°
ºoux«kmY]yzourq=k|[rilkmxr pjkmrouqo¢kmY[]#=]Hnkoux
(N i , D i 1 , . . . , D N i i )
ª[il]H]kY[]Ã}~~]Hqjr £9°¨ºrupxm]buru]Hi tuqr pilkmxvtLkr o=qou¢kY[]#tPoLu]#j]E²q[r kmrouqiH°-Õk#rsi]7tuimgkmoil]H]kYtLk¢Ýo=xkY[]]E=]Eq3k
{t + 1 ≤ B , t + 2 < t + 1 + B L(t +
1 )−1 }
kmoojnEnEp[xHªt + 1
tqt + 2
Yt¹u]}ko_P]r qkmY]bit\]ilp[[¦J[pilg~P]Exr ojïª
[s i−1 + E i , s i ]
ªh¢Ýoux&ilo=\]i ∈ {1, . . . , H }
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ªhkY[]#~[xoutu[r r kzgkmYtkkmY[]²xvilk&kz§¨otu[[rµkr o=qthyzp[\~i|tx]brqkmY[]i
¦JkmYilpj¦JpilgV~]Hxmrojïª[rsiE Z s i
s i −1 +E i
εp + (X (u))e −ε R 0 u p + (X(s)) ds
1 − e −ε R u si p + (X(s)) ds du
!
= ε 2 E Z s i
s i−1 +E i
p + (X(u)) Z s i
u
p + (X(s)) ds du
!
+ o(ε 2 ).
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M/M/1
& '' 7-
6
- - 1
B 1 1
s 0 =0 E 1 s H −1 s H B
E 0
s 1
º.rup[x]'+³]Hno=\~o3ilr kmrouqo¢³t G¨pilg¤w$]Hxmroj
ehrqnE]uª
B 1 i = s i − s i−1 − E i−1
YtuikY[]it\]jrsizkxmr[pjkr o=qtui
B
tqhgkmY[]BizkvtLkmrouqtxrµkzg¤ou¢((X (t))
ª[kmY[]nEo3]E©¤nr]Eq3k&o¢ε 2
nEtqP]#]£j~[x]Hiil]7Vtui«¢Ýo= oL§}iHªE Z
0≤u≤v≤B
p + (X(u))p + (X(v)) du dv
= E Z
0≤u≤v≤B
E ν p + (X (0))p + (X(v − u) ) du dv
.
º.rqt g=ªimr qn]
H
ri=]Eo=\B]EkmxrnHt g[rilkmxr pjkm]7§&r kmY¬~txvt\]k]Exλ/(λ + µ)
ªÄ ® ptkmrouq¶lu7¸¢Ýo= oL§}iH°
´±]&kmpxmqq[oL§ kmokmY]}]£j~tuqilrouqBo¢PkmY]
®
ptq3kmr kzg
P(t + 1 ≤ B)
ª=§&Y[rsnvYri@o¢ïnoupxim]«tx]²q[]E\]Eq3k ou¢§&Ytk}YtuiP]E]HqMjouq[]rqeh]Hnkmrouq([°¨½ ¯ C '#
P(t + 1 ≤ B)
8 < 'P(t + 1 ≤ B) = ε E ν (p + (X (0)))
µ − λ
− ε 2 E Z B
0
(B − v) E ν p + (X (0))p + (X(v)) dv
!
+ o(ε 2 ).
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