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American Open Journal of Statistics, 2011, 1, 115-127 doi:10.4236/ojs.2011.12014 Published Online July 2011 (http://www.SciRP.org/journal/ojs) Copyright © 2011 SciRes. OJS Runs and Patterns in a Sequence of Markov Dependent Bivariate Trials Kirtee Kiran Kamalja, Ramkrishna Lahu Shinde Department of Statistics, School of Mathematical Sciences, North Maharashtra University, Jalgaon, India E-mail: [email protected] Received May 13, 2011; revised June 2, 2011; accepted June 8, 2011 Abstract In this paper we consider a sequence of Markov dependent bivariate trials whose each component results in an outcome success (0) and failure (1) i.e. we have a sequence , 0 n n X n Y of - 0 0 1 1 , , , 0 1 0 1 S valued Markov dependent bivariate trials. By using the method of conditional probability generating func- tions (pgfs), we derive the pgf of joint distribution of 1 1 2 2 0 1 0 1 0 1 0 1 , , , , , ; , nk nk nk nk X X Y Y where for , de- 0,1 i 1 , i i nk X notes the number of occurrences of i-runs of length in the first component and 2 , i nk denotes the number of occurrences of i-runs of length k in the second component of Markov dependent bivariate trials. Further we consider two patterns 1 i k i Y 2 i 1 and 2 o lengths 1 k and 2 k respectively and obtain the pgf of joint dis- tribution of 1 2 , , X g method of conditional probability generating functions where f , n n Y usin 1 2 , , n n X Y number of occurrences of pattern denotes the 1 2 of length 1 2 k in the second) n components of bivariate trials. An algorithm is developed to evaluate the exact probability distributions of the vector random variables from their derived probability generating functions. Further some waiting time distribu- tions are studied using the joint distribution of runs. k first ( Keywords: Markov Dependent Bivariate Trials, Conditional Probability Generating Function, Joint Distribution 1. Introduction The distributions of several run statistics are used in various areas such as reliability theory, testing of statis- tical hypothesis, DNA sequencing, psychology [1], start up demonstration tests [2] etc. There are various count- ing schemes of runs. Some of the most popular counting schemes of runs are non-overlapping success runs of length [3], overlapping success runs of length [4], success runs of length at least , - overlapping suc- cess runs of length [5], success runs of exact length [6]. k k k k k The probability distribution of various run statistics associated with the above counting schemes have been studied extensively in the literature in different situations such as independent Bernoulli trials (BT), non-identical BT, Markov dependent BT (MBT), higher order MBT, binary sequence of order , multi-state trials etc. But very little work is found on the distribution theory of run statistics in case of bivariate trials which has applications in different areas such as start up demonstration tests with regard to simultaneous start ups of two equipment, reliability theory of two dimensional consecutive k , kr out of 1, k n : F -Lattice system etc as specified by [7]. [7] have studied the distribution of sooner and later waiting time problems for runs in Markov dependent bivariate trials by giving system of linear equations of the conditional pgfs of the waiting times. The distribution of number of occurrences of runs in the two components of bivariate sequence of trials and their joint distributions are still unknown to the literature. Consider a sequence , 0 n X n aa of -valued trials where is set of all possible outcomes of trials under study. The simple pattern is composed of specified sequence of states i.e. 1 2 k S S k a where 1 2 , , a a k a S . The number of occurrences of patterns can be counted according to the non-overlapping or overlapping counting scheme. The non-overlapping cou- nting scheme starts recounting of the pattern immediately after the occurrence of the pattern while the overlapping
Transcript
Page 1: Runs and Patterns in a Sequence of Markov Dependent ...file.scirp.org/pdf/OJS20110200006_34566710.pdfIn this paper we consider a sequence of Markov dependent bivariate trials whose

American Open Journal of Statistics, 2011, 1, 115-127 doi:10.4236/ojs.2011.12014 Published Online July 2011 (http://www.SciRP.org/journal/ojs)

Copyright © 2011 SciRes. OJS

Runs and Patterns in a Sequence of Markov Dependent Bivariate Trials

Kirtee Kiran Kamalja, Ramkrishna Lahu Shinde Department of Statistics, School of Mathematical Sciences, North Maharashtra University, Jalgaon, India

E-mail: [email protected] Received May 13, 2011; revised June 2, 2011; accepted June 8, 2011

Abstract In this paper we consider a sequence of Markov dependent bivariate trials whose each component results in

an outcome success (0) and failure (1) i.e. we have a sequence , 0n

n

Xn

Y

of - 0 0 1 1

, , ,0 1 0 1

S

valued Markov dependent bivariate trials. By using the method of conditional probability generating func-

tions (pgfs), we derive the pgf of joint distribution of 1 1 2 20 1 0 1

0 1 0 1

, , , ,, ; ,

n k n k n k n kX X Y Y where for , de- 0,1i 1, i

i

n kX

notes the number of occurrences of i-runs of length in the first component and 2, in k denotes the number

of occurrences of i-runs of length k in the second component of Markov dependent bivariate trials. Further we consider two patterns

1ik iY

2i

1 and 2 o lengths 1k and 2k respectively and obtain the pgf of joint dis-tribution of 1 2, ,X g method of conditional probability generating functions where

f ,n nY usin 1 2, ,n nX Y

number of occurrences of pattern denotes the 1 2 of length 1 2k in the second) n components of bivariate trials. An algorithm is developed to evaluate the exact probability distributions of the vector random variables from their derived probability generating functions. Further some waiting time distribu-tions are studied using the joint distribution of runs.

k first (

Keywords: Markov Dependent Bivariate Trials, Conditional Probability Generating Function,

Joint Distribution

1. Introduction The distributions of several run statistics are used in various areas such as reliability theory, testing of statis-tical hypothesis, DNA sequencing, psychology [1], start up demonstration tests [2] etc. There are various count-ing schemes of runs. Some of the most popular counting schemes of runs are non-overlapping success runs of length [3], overlapping success runs of length [4], success runs of length at least , - overlapping suc-cess runs of length [5], success runs of exact length

[6].

k kk

kk

The probability distribution of various run statistics associated with the above counting schemes have been studied extensively in the literature in different situations such as independent Bernoulli trials (BT), non-identical BT, Markov dependent BT (MBT), higher order MBT, binary sequence of order , multi-state trials etc. But very little work is found on the distribution theory of run statistics in case of bivariate trials which has applications

in different areas such as start up demonstration tests with regard to simultaneous start ups of two equipment, reliability theory of two dimensional consecutive

k

,k r out of 1,k n : F -Lattice system etc as specified by [7]. [7] have studied the distribution of sooner and later waiting time problems for runs in Markov dependent bivariate trials by giving system of linear equations of the conditional pgfs of the waiting times. The distribution of number of occurrences of runs in the two components of bivariate sequence of trials and their joint distributions are still unknown to the literature.

Consider a sequence , 0nX n

a a

of -valued trials where is set of all possible outcomes of trials under study. The simple pattern is composed of specified sequence of states i.e. 1 2 k

SS

k a where

1 2, ,a a ka S . The number of occurrences of patterns can be counted according to the non-overlapping or overlapping counting scheme. The non-overlapping cou- nting scheme starts recounting of the pattern immediately after the occurrence of the pattern while the overlapping

Page 2: Runs and Patterns in a Sequence of Markov Dependent ...file.scirp.org/pdf/OJS20110200006_34566710.pdfIn this paper we consider a sequence of Markov dependent bivariate trials whose

K. K. KAMALJA ET AL. 116

counting scheme of patterns allows an overlap of pre- specified fixed length in the successive occurrences of patterns.

Recently the study of distributions of different statis-tics based on patterns has become a focus area for many researchers due to its wide applicability area. Distribu-tion of , the waiting time for the occurrence of pattern of length in the sequence of multistate trials is studied by [1,8,9]. [10] considered the sequence

1 2 generated by Polya’s urn scheme and study the waiting time distribution of for .

, ,r kW

,

thr

r

k

,X X

, ,r k

Joint distribution of number of occurrences of pattern

1 of length 1k and pattern 2 of length 2 in n Markov dependent multi-state trials is studied by [11]. [12] considered a sequence

W 1

k

, 1, 2,iX i of - dimensional i.i.d. Random column vectors whose entries are -valued i.i.d. random variables and obtain the waiting time distribution of two dimensional patterns with general shape. The general method, which is an extension of method of conditional pgfs, is used to study these distributions by [12].

m

0,1

Even though the distribution of waiting time of the pattern of general shape in the sequence of multi-variate trials with i.i.d. components has been done, the joint distribution of number of occurrences of patterns

in the sequence of component of the -variate trials

, 1, 2, ,i i m

m thi

1 2, , , nX X X is still unknown. Here we derive the pgf of joint distribution of number of occurrences of runs in both the components of the bivariate trials and generalize this study to the distribu-tion of number of occurrences of patterns in both com-ponents of the bivariate trials.

In this paper we consider the sequence

of -valued Markov dependent bivariate trials. In Sec-

trials. In Section

. The Joint Distribution of Number of

Let

, 0n

nY

nX

Stion 2, we obtain the pgf of joint distribution of number of occurrences of i -runs of length 1

ik in first compo-nents and i -runs of length 2

ik in t second compo-nents of the bivariate trials 0,1i . We study this joint distribution of runs under th verlapping counting scheme of runs by using the method of conditional pgfs. Further in section 3, we study the joint distribution of number of occurrences of pattern 1 of length 1k in the first component and number of o rrences of pattern

2 of length 2k in the second component of bivariate 4, we develop an algorithm to evaluate

the exact probability distributions of the random vari-ables under study. As an application of the derived joint distributions, in Section 5, we obtain distributions of several waiting times associated with the runs and pat-terns in bivariate trials. In Section 6 we present some numerical work based on distribution of runs and pat-terns. Finally in Section 7, we discuss an application and

generalization of the studied distributions.

he

cu

e non-o

c

2Occurrences of Runs

0 0 1 1, , ,

0 1 0 1S

.

, 0n

n

n

Consider the sequence

X

Y

of S -valued Markov dependent bivari-

ate trials with the transition probabilities,

1i iX Xx u u ,

1

,

1, 2, ,

uv xyi i

xP p S

Y Yy v v y

i n

and the initial probabilities

0

0

πxyPY y

X x xS

y

.

for

Let

1 2, ,i i

i i

n k n kX Y

1

be the number of -runs ( = 0,1) of

le

i i

ngth ik ik mpon

2 i te n n trials associa d with the first (second ent bivariate trials (i.e. number of i -runs in

) co of 0 1 0 1, , , , , ,n nX X X Y Y Y . In this section

e derive thew joint distribution of

1 1 2 20 1 0 1, ; ,X X Y Y .

0 1 0 1, , , ,n k n k n k n k

0 1 0 1, ; ,n t t s s be the pgf of distribution of Let

1 1 2 20 1 0 1

1

, , , ,, ; ,

n k n k n k n kX X Y Y0 . Assume that for a non-nega1 0 tive

integer c n , we hav

have obs c ). We

fine

e observed until thn c trial

(i.e. we erved iX de- , 0,1, ,

i

i nY

i j 0 1 0 1, ; ,i j

c c t t s s l distribution of number of i -run

1 2 1 2, ; , , ; ,i m j m i m j m as pgf of condi-

tiona s of length 1ik in

1, ,n c nX X and number of j runs of length - 2jk in

ven that we have bserved

n cX ently h

1, , nY Y gi oXn c

0 1

0 1

, , ,n c

X

Y Y

1

Y

and curr ave i -run of

length in first component and -runs of length im j2jm in second component of bivariate trials is ob-

ed, 1 11, 2, ,i im k , 2 21, 2, ,the

serv j jm k , , 0,1.i j We define 1ca a for 0,1a . Now by ass 00 1uming π , we have,

(2.1)

Also we have,

0,0;0,00 1 0, ; ,t t s t t 1 0 1 0 1, ; ,n ns s s

1 2, ; ,i ji m j m

t t 1 10 0 1 0 1

2 2

, ; , 1 for 1, 2,..., ,

1, 2,..., and , 0,1

i i

j j

s s m k

m k i j

(2.2)

Conditioning on the first trial we have the following system of recurrent relation of conditional pgfs for

Copyright © 2011 SciRes. OJS

Page 3: Runs and Patterns in a Sequence of Markov Dependent ...file.scirp.org/pdf/OJS20110200006_34566710.pdfIn this paper we consider a sequence of Markov dependent bivariate trials whose

K. K. KAMALJA ET AL. 117

Conditioning on the next trial from each stage, we ha

if 2j

if j

1,2, ,c n .

(0,0;0,0)0 1 0 1

(0,1;0,1) (0,1;1,1)00,00 1 00,01 1

(1,1;0,1) (1,1;1,1)00,10 1 00,11 1

, ; ,n

n n

n n

t t s s

p p

p p

ve the following system of recurrent relations of con-ditional pgfs for 1,2, ,c n and , 0,1i j .

1, ; ,ii m j

2

1 2 2

1

, 1; , 1 ,1; , 1

, 1 1,

, 1; ,1 ,1; ,1

1 1, ,

j

ci j j

c

c c ci

c c c

m

c

i m j m i j m

ij ij c cij i j

i m j i j

c cij ij ij i j

p p

p p

1 11, 2, , 2i im k , 2

2 1, 2, , 2jm k ,

1 2 2

1

, ; ,

, 1; , 1 ,1; , 1

, 1 1,

, 1; ,1 ,1; ,1

1 1, ,

i j

ci j j

c

c c ci

c c c

i m m

c

i m j m i j m

ij ij c i cij i j

i m j i j

c i cij ij ij i j

p t p

p t p

1 j

1 1 1i im k ,

2

2 21, 2, , 2jm k ,

2c

1 2, ; , ,1; , 1 ,1; , 1

, 1 1,

,1; ,1 ,1; ,1

1 1, ,

i j j j

c

c c c

c c c

i m j m i j m i j m

c ij ij c cij i j

i j i j

c cij ij ij i j

p p

p p

if 1 1i im k , 2 21, 2, , 2j jm k

1 2 1 2 2

1

, ; , , 1; , 1 ,1; , 1

, 1 1,

, 1; ,1 ,1; ,1

1 1, ,

ci j i j j

c

c c ci

c c c

i m j m i m j m i j m

c ij ij c j cij i j

i m j i j

c cij ij ij i j

jp s p s

p p

if 1 11, 2, , 2i im k , 2 2 1j jm k ,

1 2 2 2

1

, ; , , 1; , 1 ,1; , 1

, 1 1,

, 1; ,1 ,1; ,1

1 1, ,

i j i j j

c

c c ci

c c c

i m j m i m j m i j m

c ij ij c i j cij i j

i m j i j

c i cij ij ij i j

1 c

jp t s p s

p t p

if 1 1 1i im k , 2 2 1j jm k ,

1 2 2 2, ; , ,1; , 1 ,1; , 1

, 1 1,

,1; ,1 ,1; ,1

1 1, ,

ci j j j

c

c c c

c c c

i m j m i j m i j m

c ij ij c j cij i j

i j i j

c cij ij ij i j

p s p

p p

js

if 1 1i im k , 2 2 1j jm k ,

1 2 1

1

, ; , , 1; ; ,1

, 1 1,

, 1; ,1 ,1; ,1

1 1, ,

i j i

c

c c ci

c c c

i m j m i m j j

c ij ij c cij i j

i m j i j

c cij ij ij i j

p p

p p

,1 ,1ci

if 1 11, 2, , 2i im k , 2 2j jm k ,

1 2 1

1

, ; , , 1; ,1 ,1

, 1 1,

, 1; ,1 ,1; ,1

1 1, ,

ci j i

c

c c ci

c c c

i m j m j i

c ij ij c i cij i j

i m j i j

c i cij ij ij i j

p t p

p t p

; ,1i m j

1 1 1i im k , 2 2j jm k if

2, ; , ,1; ,1,1; ,1, 1 1,

,1; ,1 ,1; ,1

1 1, ,

cj

c

c c c

c c c

i m j m i ji jc ij ij c cij i j

i j i j

c cij ij ij i j

p p

p p

1i

1 1i im k , 2 2

j jm k if

Thus we have t 1 1 2 20 1 0 1k k k k

for 1,2, ,c

recurren relations

of n conditional pgfs 1 and these can be written as,

0 1

1 1 1 11 2 12

0 1 0 110 0 0 0

,

, ; ,i i j j ij i j ci j i j

s0 1, ;c

t t s

A B t B s B t s t t s s

(2.3) where

20

2 2 1 21 1 1 1

(0,1;0, )(0,0;0,0) (0,1;0,1) (0,1;1,1)

(0,1;1, ) (1,1;1, ) (1, ;1, )

kc c c cc

k k k kc c c

and 1 1 1 1

1 2 12

0 0 0 0i i j j ij i j

i j i j

A B t B s B t s

is a square

x of size matri 0 1 0 1k k k k . to corresp

1 1 2 2 Each a- row of this mtrix corresponds onding element of

0 1 0 1, ; ,c

t t s s and its elements are the coefficients of elements of 0 1 0 11

, ; ,c

t t s s

. For 0c

, we have,

0 10, 1t 1 0; ,t s s

where 1 is the column vector with all the elements equal to 1.

Using (2.3) recurrently for 1, 2, ,c n , we have,

0 1 0 1, ; ,n

t t s s

1 1 1 1

1 2 120 1 0 10

0 0 0 0

, ; ,

n

i i j j ij i ji j i j

A B t B s B t s t t s s

(2.4) Hence from (2.1) and (2.4) we get the pgf of dis

tiotribu-

n of 1 1 2 20 1 0 1, , , ,, ; ,

n k n k n k n kX X Y Y as, 0 1 0 1

0 1 0 1

1 1 1 11 2 12

0 0 0 0

, ; ,t t s s

1

n

i i j j ij i ji j i j

p A B t B s B t s

(2.5)

n

Copyright © 2011 SciRes. OJS

Page 4: Runs and Patterns in a Sequence of Markov Dependent ...file.scirp.org/pdf/OJS20110200006_34566710.pdfIn this paper we consider a sequence of Markov dependent bivariate trials whose

K. K. KAMALJA ET AL. 118

where p

is the first column of identity matrix of order

3. The Joint Distribution of Number of

Let and be two pat-

nsider of patterns in

of pattern

1 1 2 20 1 0 1k k k k .

Occurrences of Patterns

11 1 2 ka a a

ch to count the num

22 1 2 kb b b

hemeer of occurrences

terns of lengths 1k and 2k respectively where , 0,1i ja b , 1 21, 2, , ; 1, 2, ,i k j k . We co

non-overlapping counting scthehiw b

urs. in a e of has to restart counting from scratch each time the pattern

1,n no verlapping oc-currences of patterns 1 in the first component of n bivariate trials (i.e. in 1 2, , , n

given sequenc

X de tes th

n trials, one

mber of non-oocc

Let e nu

X X X ) and 2,nY d

notes the number of non-ov lapping occurrences of pat-terns 2 in the second component of n bi riate tri-als ( 1 2, , , nY Y Y ). Consider the random vector 1 2, ,,n nX Y . In this section we obtain the pgf of joi distribution of 1 2, ,,n nX Y ethod of ndi-tional pgfs.

Let of joint distribution of 1 2, ,,n nX Y be

e-

nt

er

using m

vai.e. in

co

pgf 1 2,n t t t .n Assum

, we have observed until

. For c n , we define, the fol-

lowing conditionLet

e that for a non-negative integer th

c trial i.e.

1 2, ,X X

Y Y

c n n

1 2 n cY al pgfs.

, n cX

( , )i jc t be pgf of condition ribution of

r terns , ,al dist

number of occu rences of pat in 1 1n c nX X and number of occurrences of pattern 2 in

1n c n

at thn c trial) we ha

, ,Y Y of bivariate trials give obser no

ven that currently (i.e. ne of the sub- ved

patterns of 1 and 2 and n c

n c

X i

Y j

, where

iS

. jSimilarly let,

1

,,i j

c be pg nal distrition of num er of

t f of conditio bu-b occurrences of patterns 1 in

1, ,n c nX X bivariate trials giveserved the suco

and patterns in of n that at

b-pattern of first one of

2 n c

h i

1n c trial we in

, , nY Yhave ob-the

th

lengt of 1

mponent and n the sub pattern of 2 is ob-served in the second component of bivariate trials and

n c i

n cY j

X a

where 1, 2i k and 0,1j .

Let

1, ,

2

,,i j

c t be pgf of conditional distri tion of number of occurrences of patterns 1 in 1, ,n c n

buX X

and patterns in Y Y of bivariate trials 2

thn c e obse

1, ,n c trial we h

in the fi

n

avrst com

given that at the sub-pattern of pon

pattern of the

e ob d

rved none of ent and a sub 1

length j of 2 in the second compo-

nent of bivariat trials and n cis servejn c bY

where 0,1i

iX

and 21,2, ,k j .

Also let 1 2

,, ,i j

c t as pgf of onditional distribution of cpattern number of occurren in ces of 1 1, ,n c nX X

and pattern 2 in 1, ,n c nY Y of bivari

of leng f 1

ate trials givenhe sub-pattern that at obse ved t th

n c o

th i

trial we have r coi hen t

and

first mponent and a sub pa

iat s

ttern of the length j of 2 in the second compo-

nent of bivar e trial in c

jn c

aX

bY

where

11, 2, ,i k and 21,2, ,j k . Let,

1ca ai i , i k11, 2, , and 1c

j jb b , 1, 2,j 2,k .

For c n , we as esum

i

1ci

that at

1

If

thn c

observed i

ondition

trial, the

su of s n the first

compone riate trials. we c on the next

trial as

b-pattern of

nt of biva

n c

n c

X

Y

length i

1 a

1 1n cy

i.e. of leng-

th i of 1

the sub-pattern

observ d at thn c trial breaks at

1

e st

n c trial then to check whether any sub-pattern

of 1 of length r r i 1

has occurred, we define the

indicator fu ion irnct as,

1 2 2 3 1 1, ,..., , ci r i r r i r ia a a a a a a

1, 1;i k r i

1ir I a

1,2, .

Similarly we hav ndicato

e i ction r fun 2jr as,

21 2 2 3 1, ..., , c

jr j r r j r jI b b b b b b b

1, ,j k r j

,j r

2 1;

b

2,

1

.

Let

1 1 1irr1 21max , m , 1,2, ,

1,2, 1

i iir

r iu u r i

,

1

ax

,i k

2 22

2

ax and ax 1, 1, 2, ,

1,2 , 1

jjr jr

r jv r r

j k

11mjv

m

,

j

Assuming 00π 1 , we

1 2t t

have,

(3.1)

We also have,

0,01 2, ,n n t t

,0 1 for ;i j i

t Sj

Copyright © 2011 SciRes. OJS

Page 5: Runs and Patterns in a Sequence of Markov Dependent ...file.scirp.org/pdf/OJS20110200006_34566710.pdfIn this paper we consider a sequence of Markov dependent bivariate trials whose

K. K. KAMALJA ET AL. 119

2

,0, 1i j t

1

,10,

2

1 for 1, 2, , a

for 0,1 and 1, 2, , ;

i j t i k

i j k

nd 0,1;j

1 2

,1 20, , 1 for 1, 2, , and 1, ,i j t i k j k . (3.2)

Now for each denotes the number of trials remaining to observe) we condition on the nex to obtain the recurrent relations of conditional pgfs as follows.

2,

1 c n ( c t trial

1 2 211

11 1

11 1 1 1

, 1,,

,1,

11,, ,

c

c cc

c c c

c ij ij a b

a bb

ccij a b ij a b

t p t p t

p t p t

1

1 1

,11,1,, 1,

cai ja b c c

if 1, 0,i j ,

1 11 1 2

2 1

1 2 211

2 1 1 1

111

1

11 1

, 1,1,, 1, ,

,1 ,1

1 11, , 1,,

, ,

1 1 11,,

1,

1,,

1

i i

i ci

ci i

i c c ci

c ci i

c

ci i

i j ia j a bc c

u ai ic ca j a b

u b a bi icca j a b

i b

ca j a b

t p t

p t u t u

p t u t u

p t

if

1

11,2, , 2; ,1i k j 0

1 11 1 2

2 1

2 211

1 12 1

211

1

11 1

, 1,1, 1, 1, ,

,1 ,1

1 11, 1,,

,( , )1 1 11,,

1,

11,,

1

1

i i

i ci

ci i

c ci c i

c ci i

c

ci i

i j ia j a bc c

u aic ca j a b

a bu b i icca j a b

i b

ca j a b

t p t t

p t u t

p t u t

p t t

iu

u

if

1 1; 0,i k j 1

1

1 11 1 2 11

11 1

11 1 1 1

,1, 1,1,, 1, , ,

,1,

11,, ,

c

ci i

c cc

c c ci i

ai ja j a bc c ca j a b

a bb

cca j a b a j a b

t p t p t

p t p

21,

t

if 1

Similarly we have recurrent relations of the condi-tional pgfs

1, 0,i k j .

2

,,i j

c t for k as follows.

20,1 and 1, 2, ,i j

1 12 1 2

2 11 1

1 1 12

21 1

1

21 1

, 1, 1,, 1, ,

,

, ,

1 1 11,,

, 1

1,,

1

j j

cj j

jc c cj

c cj j

c

cj j

i j jib a bc c

a b

a v a bj jccib a b

a j

cib a b

t p t

p t v t v

p t

if

12

1

1, 1,

1 11, , 1, 1j c

jv bj jc cib

p t v t v

21, 2, , 2;j k

1 12 1 2

12

1 2 11 1

1 1 12

21 1

1

21 1

, 1, 1, 2, 1, ,

1, 1,

1 11, , 1,,

, ,

1 1 11,,

, 1

21,,

1

1

j j

j cj

cj j

jc c cj

c cj j

c

cj j

i j jib a bc c

v bj jc cib a b

a v a bj jccib a b

a j

cib a b

t p t t

p t v t

p t v t

p t t

v

v

if 2 1;j k

1

1 12 1 2 11

1 1 1

11 1 1 1

,1, 1,1,, 1, , ,

1, ,

11,, ,

c

cj j

c c c

c c cj j

ai jib a bc c cib a b

b a b

ccib a b ib a b

t p t p t

p t p

21,

t

if 2j k

The recurrent relations of the conditional pgfs

1 2

,, ,i j

c t for 11, 2, ,i k and are as follows.

21,2, ,j k

1 11 2 1 2

12

1 2 11 1

2 1

1 2 11 1

1 11,c c

i j jca b b

p

, 1, 1,, , 1, ,

1, 1,

1 11, , 1,,

, 1 , 1

1 11, , 1,,

,

1

1

i j i j

j cj

ci j i j

i ci

ci j i j

i

i j i ja b a bc c

i v i bj jc ca b a b

u j a ji ic ca b a b

a

t p t

p t v t v

p t u t u

1 2

2 1

1

1 2

2

1 1

,

1 11,

,

1 11,

,

1 1 1

1

1

1 1

i cj

jci

c ci j

u b i jc

a v i jc

a b i jc

t u v

t u v

t u v

if

2 2,

1 1,

jiu v i jt u v

1 21, 2, , 2; 1,2, , 2i k j k

1 11 2 1 2

12

1 2 11 1

2 1

1 2 11 1

1 1

, 1, 1, 1, , 1, ,

1, 1,

1 11, , 1,,

, 1 , 1

1 11, , 1,,

,

1

1

i j i j

j cj

ci j i j

i ci

ci j i j

c ci j i j

i j i ja b a bc c

i v i bj jc ca b a b

u j a ji ic ca b a b

ca b a b

t p t t

p t v t

p t u t

p

1v t

u

2 2

1 2

2 1

1

1 2

2

1 1

,

1 11, ,

,

1 11,

,

1 11,

,

1 1 1

1

1

1 1

ji

i cj

jci

c ci j

u v i j

u b i jc

a v i jc

a b i jc

t u v

t u v

t u v

t u v

if 1 21; 1,2, , 2i k j k

Copyright © 2011 SciRes. OJS

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K. K. KAMALJA ET AL. 120

1 11 2 1 2

12

1 2 11 1

1

21 1

1 1 12

21 1

, 1, 1,, , 1, ,

1, 1,

1 11, , 1,,

, 1

1,,

, ,

1 1 11,,

1

1

i j j

j cj

ci j j

c

ci j j

jc c cj

c ci j j

i j ja b a bc c

v bj jc ca b a b

a j

ca b a b

a v a bj jcca b a b

t p t

p t v t

p t

p t v t

v

v

1 2if ; 1,2, , 2i k j k

1 11 2 1 2

12

1 2 11 1

2 1

1 2 11 1

1 1

, 1, 1, 2, , 1, ,

1, 1,

1 11, , 1,,

, 1 , 1

1iu 1 21, , 1,,

,

1

1

i j i j

j cj

ci j i j

i ci

ci j i j

c ci j i j

i j i ja b a bc c

i v i bj jc ca b a b

u j a j ic ca b a b

ca b a b

t p t t

p t v t v

p t t u t

p

2 2

1 2

1 22 1

1 2

1 1

,

1 11, ,

,( , )1 1 1 11, 1,

( , )1 1 1

1 1

1 1

ji

jci c ij

c ci j

u v i j

a vu b i j i jc c

a b i jc

t u v

t u v t u v

t u v

1 2if 1,2, , 2; 1i k j k

1 11 2 1 2

12

1 2 11 1

2 1

1 2 11 1

1

, 1, 1, 1 2, , 1, ,

1, 1,

1 1 1t1, , 1,,

, 1 , 1

1 11, , 1,,

,

1

1

i j i j

j cj

ci j i j

i ci

ci j i j

ci j i j

i j i ja b a bc c

i v i bj jc ca b a b

u j a ji ic ca b a b

a b a b

t p t t t

p t v t v

p t u t u

p

2t

2 2

1 21

12 1 2

1 2

1 1

,

1 11, ,

,,

1 1 1 11, 1,

,

1 1 1

1 1

1 1

ji

c

jci cij

c ci j

u v i jc

a vu b i j i jc c

a b i jc

t u v

t u v t u v

t u v

1 2if 1; 1i k j k

11 2 1 2

12

1 2 11 1

1

21 1

1 1 12

21 1

, 1, 1, 2, , 1, ,

1, 1,

1 11, , 1,,

, 1

21,,

, ,

1 1 11,,

1

1

i j i j

j cj

ci j j

c

ci j j

jc c cj

c ci j j

i j ja b a bc c

v bj jc ca b a b

a j

ca b a b

a v a bj jcca b a b

t p t t

p t v t

p t t

p t v t

v

v

1 2if ; 1i k j k

11 2 1 2

2 1

1 2 21 1

11 1

2 1 1 1

11 1

, 1,1,, , 1, ,

,1 ,1

1 11, , 1,,

1,

1,,

, ,

1 1 11,,

1

1

i j i i

i ci

ci j i

ci

ci j i

i c c ci

c ci j i

i j ia b a bc c

u ai ic ca b a b

i b

ca b a b

u b a bi icca b a b

t p t

p t u t

p t

p t u t

u

u

1 2if 1, 2, , 2;i k j k

11 2 1 2

2 1

1 2 21 1

11 1

2 1 1 1

11 1

, 1,1, 1, , 1, ,

,1 ,1

1 11, , 1,,

1,

11,,

, ,

1 1 11,,

1

1

i j i i

i ci

ci j i

ci

ci j i

i c c ci

c ci j i

i j ia b a bc c

u ai ic ca b a b

i b

ca b a b

u b a bi icca b a b

t p t t

p t u t

p t t

p t u t

u

u

1 2if 1;i k j k

1

1 11 2 1 2 21 1

1 1 1

11 1 1 1

,1, 1,1,, , 1, , 1,,

1, ,

11,, ,

c

ci j i j

c c c

c c ci j i j

ai ja b a bc c a b a b

b a b

cca b a b a b a b

t p t p t

p t p t

c

1 2if ;i k j k

The above system of 1 22 2k k fs

recurrent re-lations of conditional pg ,i j

c t , , 0,1i j ;

1

,,i j

c t , 0,1j ; 10,1, , ;i k ,i j t , 2,c

20,1; 1, 2, ,i j k and 1 2

,, ,i j

c t

1 21, 2, , ; 1, 2, ,i k j k can be written as follows.

1 1 2 2 12 1 2 1

1 1 2 2 12 1 2

if 2,3, ,

1 if 1c

c

A B t B t B t t t c nt

A B t B t B t t c

(3.3) where 1 is column vector with all its elements 1 and

n

t is column vector with its elements as follows.

1

1 1 2

2 1 2

2 1 2 1 2 1 2

1,0 ,1 0,10,0 0,1 1,0 1,1, , ,

1, 1,1 1,2 ,, , , , , , ,

... kc c c c c c c

k k kc c c c

From (3.1) we get,

1 2 1 2, ' ,n nt t p t t

p is first column of identity matrix of order where 1 22 2k k .

The recurrent us 1 2, ,,n nX Y e of (3.3) gives the pgf of as follows.

1 1 2 2 12 1 2' 1n

n t p A B t B t B t t (3.4)

Copyright © 2011 SciRes. OJS

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K. K. KAMALJA ET AL. 121

4. Exact distribution of 1 1 2 20

0 1 0 1

, , , ,, ; ,

n k n k n k n kX X Y Y

1 0 1

We note that the pgf of art

, ,,n nX Y

0 1;Y Y1 2

pg ,

is a p icular

case of f of . Hence we de-

velop an algorithm to the exact probability distri-

bution of

beapp ility distribution of

rve that t

involves matrix polynomial in

1 1 2 20 0 1

0 1

, , , ,,

n k n k n kX X

1n k

obtain

1 1 2 20 1 0 1

0 1 0

, , , ,, ;

n k n k n k n kX X Y

lied to obtain the exact probab

1 2 from its pgf.

1,Y which can further

, ,,n nX Y

Obse he pgf of joint distribution of

1 2 21 0 1

0 1 0 1

, , ,, ; ,

n k n k n kX X Y Y as obtained in (2.5) in general 1

0,n k

0 1 0 1, ; ,nP t t s s 0t , 1t , 0s and 1s of order n where

0 1 0 1

1 1 12 12

0 0 0 0

, ; ,n

n

i i j j ij i ji j i j

P t t s s

11A B t B s B t s

.

Hen e joint probability distribution can be ob-din

ce thtained by expan g the polynom respect to ial with

0t , 1t , 0s and 1s . That is,

2 20 1

1

0 1 0 10, ,

0 1 0 1 0 1 0 1

, ; ,

coefficient of in , ; ,

n k n k

yn

P X x X x Y y Y y

t t s s t t s s

1 10 1

0 01

0 1, ,n k n k

x yx

1

i.e.

0 1 0 1, , , ,

co cient of in , ; ,

n k n k n k n k

x yt s t t s s (4.1)

10 , ;P X y1 2 2

1 0 1,

effi n

X x Y Y

edious since tive operation ting recurrent relations are fo

0 1 0 1

Exact formula to obtain the coefficient matrix is quiet t multiplication of matrices is not commuta-

. But the interesund between these coefficient matrices. Let

; y be the coefficient matrix of 0 1 0 1, ; ,n nC x x y y C xx yt s in the expansion of ma l 1 0 1; ,nP t s s and for n

trix polynomia, let 0 , t 1

; , 0,1, , for 0,1n i iD x y x y n i . The following

Lemma gives the recurrent relations of the coefficient matrices of ;nC x y with 1 ;nC x y .

Lemma 4.1 Let ;nC x y be the coefficient matrix

of x yt s in the expansion of the matrix polynomial

0 0 1, ; ,nP t t s s Then 1 ;nC x y satisfies the following

re lation. current re

1

11

1 1 10

1

i

21 1 1

0

1 112

1 1 1 1 10 0

; ;

; 0

; 0

; 0;

n n

n ii i

n jj jj

n iji j i ji j

C x y C x y A

C x e y B I x e

C x y e B I y e

C x e y e B I x e y

0e

(4.2) with 1 0;0C A , 1

1 1;0 iiC e B , 11 10; jjC e B

and 121 1 1; iji jC e e B for , 0,1i j . Here ie is the

thi row of the identity matrix of order 2. Proof Obviously for 1n , we have,

1

1if ; 0, 0,1iB x e y i

21 1

if

; if 0; ,

se

i

j j

A x

C x y B x y e

O

w atrix of

21 1if ; , 0,1; 0,1

otherwi

ij i iB x e y e i j

0; 0y

0,1j

here O is the null m same order as that of A. For 2n , observe that 2 ,C x y satisfies (4.2). Assu at E (4 ) is trume th quation e for some .2 2r r n .

ve, Hence we ha

1 11 2

1 112

0 0 0 0 ,

,r

r

x yi i j j ij i j r

i j i j x y D

A B t B s B t s C x y t s

Then

11 1 1 1

1 2 12

0 0 0 0

1 1 1 11 2 12

0 0 0 0

1 1 1 11 2 12

0 0 0

11 2

0

r

i i j j ij i ji j i j

r

i i j j ij i ji j i j

i i j j ij i ji j

i i j ji j

A B t B s B t s

A B t B s B t s

B t s B t s

A B t B s

0

,

i j

x y

A B

C x y t s

( , ) r

rx y D

1

1 1 112

0 0 0

11

1 1 1 1( , ) 0

12

1 1 1

1 1

; ; 0

; 0

0; 0

r

ij i ji j

r r ii ix y D i

r jj j

x yi j

B t s

C x y A C x e y B I x e

C x y e B I y e

C e

e y e t s

0

1

j

1

;x e y1 1 10 0

r i ji j

12ijB I x

Copyright © 2011 SciRes. OJS

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K. K. KAMALJA ET AL. 122

Hence we get the required proof of the lemma. Theorem 4.1 The exact probability distribution o

is given by,

f

1 2 21 0 1

0 1 0 1

, , ,, ; ,

n k n k n kX X Y Y 1

0,n k

1 1 2 20 1 0 1

0 1 0 1

, , , ,( , ) ; ( , )

' , 1

n k n k n k n k

n

P X X x Y Y y

p C x y

, (4.3)

where ,nC x y is the coefficient matrix of x yt s in expansion of matrix polynomial and it satisfies (4.2)

Proof The proof follows by applying the Lemma 4.1 to matrix polynomial involved in the

pgf of distribution of in (2.5).

Remark 4.1 The expected number of failure-runs of length in first components of Markov dependent bivari ials is given by,

0 1 0 1, ; ,nP t t s s

0 1 0 1, ; ,nP t t s s0 1 0 1 1 2 2

0 1 0 1

1

, , , ,, ; ,

n k n k n k n kX X Y Y

10k

ate trn

1 00

00 1,

d,1;1,1

d tn kE X t

t .

On simplifying this expression, we have,

10

10 1 2 2 12 12 121 0 1 01 10 11,

1

1 120 01

'

1

n j

n kj

E X p A B B B B B B

B B

(4.4) 5. Waiting Time Distributions Related to

The exact probability di

from its pgf given in (2.5) can

be expressed as,

Runs and Patterns

stribution of

1 1 2 20 1 0 1

0 1 0 1

, , , ,, ; ,

n k n k n k n kX X Y Y

1 1 2 20 1 0 1

0 1 0 1

, , , ,

11 1

( , ) ; ( , )

;

0

n k n k n k n k

i

1

1 10

' ; 0n n

12

1 1 10

; 0n jj jj

C x y e B I y e

1 1

1 1 1;n i jC x e y 0 0

121 10; 1

i j

ij i jI x e y e

i i

P X X x Y Y y

y B I x e

e

B

(5.1) The components of the above expressio an be inter-

preted as follows.

i

p C x y A C x e

n c

1 1 2 20 1 0 1

1 1 2 20 1 0 1

1

0 1 0 1

, , , ,

0 1 0 1

1, 1, 1, 1,

( , ) , ( , ) ;

( , ) , ( , )

n

n k n k n k n k

n k n k n k n k

P X X x Y Y y

' ; 1p C x y A

0,1i ,

X X x Y Y y

For

1 1

0 1

0 1 0 1

0 1

1, 1,

;

( , )n k n k

y

1 1 2 20 1 0 1

2 20 1

, , , ,

0 11 1, 1,

( , ) , ( , )

, ( , )

n k n k n k n k

i n k n k

P X X x Y Y

11 1' ; 1n iip C x e y B

X X

,

x e Y Y y

and

1 1 2 20 1 0 1

1 1 2 20 1 0 1

21 1

0 1 0 1

, , , ,

0 1 0 111, 1, 1, 1,

' ; 1

( , ) , ( , ) ;

( , ) , ( , )

n ii

n k n k n k n k

in k n k n k n k

p C x y e B

P X X x Y Y y

X X x Y Y y e

.

Similarly for 1, 0,i j ,

1 1 2 20 1 0 1

121 1 1

0 1 0 1

, , , ,

0 1 0 1

' , 1

( , ) , ( , ) ;

( , ) , ( , )

n iji j

n k n k n k n k

p C x e y e B

P X X x Y Y y

X X x e Y Y y e

(5.2) so that

1 1 2 20 1 0 1

1 11, 1, 1, 1,i jn k n k n k n k

1 1 2 20 1 0 1

1 1 2 20 1 0 1

1 1 2 20 1 0 1

1 1 2 20 1 0 1

1 10 1

0 1 0 1

, , , ,

0 1 0 1

, , , ,

0 1 0 1

1, 1, 1, 1,

10 1 0 1

, , , ,0

0 1

1, 1,

( , ) ; ( , )

( , ) , ( , ) ;

( , ) , ( , )

( , ) , ( , ) ;

( , )

n k n k n k n k

n k n k n k n k

n k n k n k n k

n k n k n k n ki

n k n k

P X X x Y Y y

P X X x Y Y y

X X x Y Y y

P X X x Y Y y

X X x

2 20 1

1 1 2 20 1 0 1

1 1 2 20 1 0 1

1 1 2 20 1 0 1

1 101, 1,n k n 1

0 11 1, 1,

10 1 0 1

, , , ,

0 1 0 111, 1, 1, 1,

1 10 1 0 1

, , , ,0 0

0 1

, ( , )

( , ) , ( , ) ;

( , ) , ( , )

( , ) , ( , ) ;

( , )

i n k n k

n k n k n k n k

jn k n k n k n k

n k n k n k n ki j

k

e Y Y y

P X X x Y Y y

X X x Y Y y e

P X X x Y Y y

X X

0j

2 20 1

0 11 11, 1,, ( , )

n k n kx e Y Y y e

(5.3) The above interpretation is useful for deriving differ-

ent waiting time distributions. Let

i j

0iF

ccur for thov de

be the event that failure-run of lengtho e first time in the component of thMark pendent bivariate trial

0ike

this and 1

iF be the that success-run of length r fo e first timth mponent of th ark ent biva

event

1ik

e Moccu

ov r th

depende in riate e thi co

trials 1,i 2 . Let be the waiting time for sooner occurring

n SW

event betwee 10F , 2

0F 11F , 2

1F . To obtain the distri-

Copyright © 2011 SciRes. OJS

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K. K. KAMALJA ET AL. 123 bution of sooner waiting time we define the following random variables.

: The waiting time for sooner occurring event bet

,i

S jWween 1

0F , 20F 1

1F , 21F given that i

jF is the sooner i. thevent ( e. j -run of leng i

jkent)

of component of bi and

th

1, 2i

variate trials is the sooner ev i 0,1j . ijW

-r: The waiting time for the first occurrence of

un of lengthj ijk

X in the component of the

bivariate trials 1,2i and

thi

, 0n

n

nY

, 0,1j .

12ijW

events : The waiting time until the occurrence of both

1iF and 2

jF simultaneously, 1 (i.e. - ru h the first compone rle

, 0,i j nt and

iun of n of l

ngth engt

2

1i ink j -

jk ccur si

in nd compone vari usly).

Then we have,

j

. (5.4)

f

tmu

he secoltaneo

nt of the bi atetrials o

1 11 2, ,

0 0

1 112

S S i Si j

P W m P W m P W m

P W m

0 0

iji j

Let t , i t , i tS ,S j j and be the pg of SW , ,

iS jW , i

ij tjW and 12

kjW , 1, 2i and , 0,1k j respectively. In the next sub-section we obtain the sooner waiting time distribution. 5.1. Sooner Waiting Time Distribution

The probability that 0-run of length 10k (i.e. event 1

0F )

occurs for the first time at thm trial given that none of

the events 20F 1

1F , 21F ccu ntil

w

has o rred u thm trial

1. .i e P W m written as follo s.

,0S can be

1 1 2 20 1 0 1

0 1 0 1

, , , ,, ; , 1,0,0,0 ;

m k m m k n kP X X Y Y

1 1 20 1 1

1 0 1

1, 1, 1,

'0

, ; ,0

k

m k m k m kX Y

e p

20

0

1,, 0,0,0

m kX Y

1,0SP W m

' 11 0

1 1 10

0,0,0,0 1

1

m

m

p C B

p A B m k

Henc gf of 1,0SW can be given as,

1 1At B1

,0 'S t t p I 01.

Similarly the probability that 1-run of length (i.e.

event

11k

11F ) occurs for the first time at tri

that none of the events

thm al given 1

0F 20F , 2

1F has oc

written

curred

1 1 2 20 1 0 1

,1

0 1 0 1

, , , ,, ; , 0,1,0,0 ;

S

m k m k m k m k

P W

P X X Y Y

1 1 2 20 1 0 11, 1, 1, 1,

1

, ; , 0,0,0m k m k m k m k

X X Y Y

1

0 1 0 1

1

,0

' 0,1,0,0 1m

m

p C B

1 1 11 1' 1mp A B m k

Hence pgf of 1,1SW is,

until

as follows. thm trial m1,1. . Si e P W can be

1

,1S p I t

Similarly

1 111t t A B .

2,0SP W m and 2

,1SP W m is given by,

2 1' 1m 2,0 0SP W m p A B

2 1,1 1' 1m

SP W m p A B 2

and pgf of is, 2,S jW

12 2, ' 1,S j jt t p I At B j .

1

0,1

Now the probability that both events and 2jF iF

occurs simultaneously for the first time at trial thm

12,. . i ji e P W m can be written as follows.

1 1 2 20 1 0 1

00 , , , ,

1

( ) 1,0,1,0 ;

,0

m k m m k m kP X

1 1 2 20 1 0 1

0 1 0 1

1, 1, 1, 1,

12 1200 00

, ; , 0,0 ,0

' 0,0,0,0 1 ' 1

m k m k m k m k

mm

X X Y Y

p C B p A B

12 0 1 0 1, ; ,W m P X Y Y k

1 10

1 1 2 20 1 0 1

0

,

0 1 0 1

1, 1, 1, 1,

12 1 1201 01

, ; ,

, ; , 0,0,0,0

' 0,0,0,0 1 ' 1

m k

m k m k m k m k

mm

X

X X Y Y

p C B p A B

2 21 0 1

12 0 1 101 , , ,

1,0,0,1 ;m k m k m k

P W m P X Y Y

1 1 2 20 1 0 1

1 1 2 20 1 0 1

12 0 1 0 110 , , , ,

0 1 0 1

1, 1, 1, 1,

12 1 1210 10

, ; , 0,1,1,0 ;

, ; , 0,0,0,0

' 0,0,0,0 1 ' 1

m k m k m k m k

m k m k m k m k

mm

P W m P X X Y Y

X X Y Y

p C B p A B

10

12 011 ,

,m k

W m X

1 2 2

1 1 2 20 1 0 1

1 0 1

, , ,

0 1 0 1

1, 1, 1,

12 1 1211 11

( ; , ) 0,1,0,1 ;

, , 0

' 0,0,0,0 1 ' 1

m k m k m k

m k m m k

mm

P P X Y Y

X X Y

p C B p A B

In general,

1 0 1

1,; ,0,0,0

k m kY

12 1 2, ' 1, ,m

i 0,1ijW p A B i j

Also pgf of is,

jP m

12ijW

1 12' 1ijijt t p I At B

Hence from (5.4), the exact probability distrib tion of u

Copyright © 2011 SciRes. OJS

Page 10: Runs and Patterns in a Sequence of Markov Dependent ...file.scirp.org/pdf/OJS20110200006_34566710.pdfIn this paper we consider a sequence of Markov dependent bivariate trials whose

K. K. KAMALJA ET AL. 124

random variable SW is given by,

2 1 1 1

1

1 0 0 0

' m iS j

i j i j

P W m p A B B

,

1 1 2 20 1 0 1min , , ,m k k k k .

12 1ij

(5.5

The pgf of is given by,

)

SW

2 1 1 1

1 12

1 0 0 0

' 1iS j

i j i j

t t p I At B B

ij

(5.6)

Here we note that it is quiet difficult to study the later waiting time distribution between 1

0F , 20F 1

1F , 21F ,

particularly when one is interested ining time distribution for the later otween more than two events. For thbution of later occurring event betw the components of the bivariate trialterns in the two components of bivacan be developed in general. For thderive the waiting time distributi event between the two events

stuccu

e waitineens or

is we reon of l

dyingrring

g tim any twfor th

riate trials thfer [1

ate

the even

e do run

e twoe th3]

r occu

wait-t be-istri-s in

pateory

who rring

-

0F and 1F where iF

0,1i for the dependentof occurreanof

is the event that -rfirst time in the sequence er

BT. [13] use the nnces of 1-runs (i.e

f occurren s of ( )

5.2. Waiting Time Distribution for Runs Let

i

joi.

ce

unof

t di succes

0-

of lehighstributs-runsruns

ngth orde

ion o) i.e.

ik ocr Markf nu

of length failure

cursov

mber

1krunsd the number o

length k . 0

,i

jr iW

un of lbe the waiting time for the ccurrence of

-r ength

thir o

i jik for the com t of bivariate

thj ponentrials, 0,1i ; 1, 2j . We obtain the distribution of

,i

jr iW using distr tion of

,ibu j

i

j

n kX number of occur-

rences of run of length i - jik

1 ; stribu

for the com nt of bi ate trials . T pgf

of jo

(2.5) is as

follows.

thjhe

pone

0 1 0 1, ; ,n t t s s f n vari 0,i

int di1

1, 2j tion o

1 1 2 20 1 0 1

0 1

, , , ,, ; ,

n k n k n k n kX X X as obtained in 0X

0 1 0 1

1 1 1 11 2 12

0 0 0 0

'

n

i i j j ij ji j i j

p A B t B s B

In particular pgf of marginal distribution of 10

1

,n kX is

obtained by setting 1 0 1

, ; ,

1

n

i

t t s s

t s

1t s s in the pgf

0 1 0 1, ; ,n t t s s o f 1 1 2 20 1 0 1

0 1 0 1

, ,0 , ,1 , ,0 , ,1, ; ,

n k n k n k n kX X Y Y a n d

is as follows.

0

11 1 2 12 12 12 120 0 1 00 0 01 0 10 11

0

,1;1,1

'

n

n

jj

t

p A B t B B B t B t B

Let pgf of ,

1

ji

j

n kX be ,

j jn i it for 0,1i ; 1, 2j .

Then pgf of 10

1

,n kX in (5.7) can be expressed in a simp

fied form as follows.

li-

1 1 1 1 1 1,0 0 0 0 0 0 0,1;1,1 'n nt t t p A D t

1 1 2 2 12 12

1n

here w 0 1 0 1 10 11A A B B B B B 1

a rib

and

d from emma 4

1 12 120 0 00 01D B B B . The exact prob bility dist ution of 1

0

1

,n kX can be

obtaine L .1 as follows.

11 1P X r p r (5.8)

0, nn k

where

'C

nC r is the c ix of 10

rt

mial 1 1 10 0 0

noefficient matr in the

matrix

B

(5.7)

polyno A D t and in for general2 m n mC r satisfies the recurrent relation

1m D 1 1C r1 0 1m mA 0

with

s ma

C r C r

10

11 0

if 0

if 1

otherwise

A i

C i D i

O

where O is the null matrix of order same a trix 10A and 1

0D . The pro 5.8) can be wri as follows.

bability in ( tten

10,n k

P X 1 1 11 0 1 0' 1 1n nr p C r A C r D

The above components of can be in-terpreted as follows.

10

1

,n kP X r

1 10 0

1 1 11 0 , 1,

' 1 ;n n k n kp C r A P X r X r

1 10 0

1 1

, 1,1 1

n k kD X r1

1 0' ;n np C r P r X

(5.9

ve,

)

Now we ha

1 10 0

10 0, 1,

; 1k m k

r X r0

1 1,0r m

P W m P X

Using the pgf of and interpretations in .9) ,

10

1

,n kX (5

we have

0

1 1,0 1 0 0' 1 1m D r mP W p C r

Particularly when 0 1r , we have,

1 1m 11,0 ' 1P W m p A D

The pgf of is given by,

0

11,0W

1

011 10's s p I A s

and formula for

D

exact probability is

11 1 11,0 0 0 1

mP W m p A D

,

Similarly waiting time distributions of

10m k .

,i

jr iW , 0,1i

and 1, 2j can be obtained.

Copyright © 2011 SciRes. OJS

Page 11: Runs and Patterns in a Sequence of Markov Dependent ...file.scirp.org/pdf/OJS20110200006_34566710.pdfIn this paper we consider a sequence of Markov dependent bivariate trials whose

K. K. KAMALJA ET AL. 125 6. Numerical Study

s section we present the numerical study based on the joint distribution of patterns in the sequence of bi

dependent bivariate trials with with transition probabilities as follows.

Let and . The joint distribute numerically for

In thi

variate trials. We consider the sequence

, 0n

n

Xn

Y

of 0 0 1 1

, , , -valued Markov

0 1 0 1

00π 1

00,00 0.2p , 00,01 0.3p , 00,1p 0.1 ,

01,00 0.3p , 01,01p 0 0.4 , 00,11p

0.1, 01,10 0.5p , 01,11 0.1p ,

10,00 0.1p , 10,01 0.4p , 10,10 0.3p , 10,11 0.2p ,

11,00 0.2p , 11,01 0.2p , 11,10 0.2p , 11,11 0.4p

1 01

2 110 valuated

ion of

1 2, ,,n nX Y is 10n us-heorem 4.1. Th d described in ng

cation and Extension

[14] introduced the two-dimensional engineering system co of nents arranged in

-rows and -colum system and its compo- can be n wo g or failed state. The system

components fails. Particularly, for ulate the states of the comp as a sequence of

me that the failed state

state 0

ingjoinTa

the algorithm given in T 1 2, ,,n nX Y is

e evaluatethe followit pmf of

ble 1.

7. Appli

nsisting of a grid n compo mns. Therkin

1, we cahis sy

mnentsfai

indcomand in

n either i

ls if and only if a grid of size r sn form

stem

1, 2,

m r onents in t

otherwise. For

n thi ependent bivariate trials. We assu

ponent in a column is in state 1 if it is in ,i n we define,

1 if first r components in column are ile

wise

th

i

iX

in fa d state

0 otherand

1 if last r component s in column arein failed stateth

i

iY

0 otherwiseThe reliability of consecutive- ,r s -out-of- 1,r n :

F-Lattice system can now be obtained simply by using the joint distribution of as, P(consecutive -o Fworks) =

1 2, ,,n nX Y

ut-of- 1,r n :- ,r s -Lattice system 0 ,

1 2, ,n n

where 1 is 1-run of length 0,P X Y

s first component and 2 is 1-run of leng

in theth s in the second component

of the bivariate trials. Extending the concept of bivariate trials to mu vari-

ate trials, the joint distributions of num er of occuof patterns of length

ltib rrences

i ik 1,2, ,i m ials can be used

m.

in the compone -variate t to

out-o

Tab

thi get the nt of

f-

m

,m n

r

: F-Lattice systereliability of general two-dimensional consecutive-

le 1. Distribution of

r s -

1 210, 10,, X Y

210,

.

Y

110,X

0 1 2 3 Sum

0 0.00257 0.00666 0.00179 3.5E–05 0.01106

1 0.04765 0.08133 0.02006 0.00044 0.14949

2 0.16288 0.21551 4793 0.00113 0.42744

3 0.14927 0.15937 0.03184 0.00075 0.34122

4 0.03465 0.0294 0.0049 9.9E–05 0.06912

5 0.00101 7.3E–05 1.2E–06 0.00167

Sum 0.39803 0.49285 0.10666 0.00245 1.00000

0.0

7

0.00058

The pgf 1 2, , ,n mt t t int distributio

in t of jo n

of , , 1, 2, ,inX i m

patterns i

, the number of occurrences of of length

-variate trials obtained in ik in the component of general by ng the method

nditional pgfs is of form,

thi usim

of co

12...1 , 1

n i ii i j

1 2' ... ... 1

n

n m

ij i j k kt p A B t B t t B t t t

e Le for thebility dist ibuti of

i j (7.1)

Extending th mma 4.1 pgf in (7.1) exact joint proba r on , , 1, 2, ,

i

inX i m can

i

be obta d. Th bove study of runs a d patterns can be extended

in another direction by ge ralizing the sequence of M

nee a n

ne

ri o deriving th is

arkov dependent bivariate trials to the sequence of Markov dependent multivariate trials. In the following, we discuss b efly the meth d of e joint d -

tribution of 2 2 21 2 21

, , , , , ,, , ,

r rn k n k n kY Y Y

where 2, , iin k

Y

,

1i two dim

2i

, 2, , r otes the number o den f occurrences of f rectangu shape ensional patterns o lar

i r 1, 2, , multivariate trials.

in the sequence of Markov dependent

Let , m'2

1 2 , , 0,1 1, 2,m m iS X x x x

so that

, x ; i

2mS# m2 . Consid q e

a d er the se uence of m -variat

2mS -v lue ovd Mark depen ent trials 0

dependent trials ,iX i . Let the

of these Markov transition probabilities 0 be, ,iX i

1rr x yP X y X x P , 2m,x y S

and initial probabilities be

, 1r .

20 x mS . P X x x

nsid w n at rec r sha

Co er the t o dime sional p tern of tangulape, 2

1i i 2 iikia a a 1, 2, ,i r where 2

1i i2 ,i mika a S e

number of occurrence trials , , a . Let 2, , ii

n kY

s of patterns , 1,2, ,i r

2

i in n

be th

Copyright © 2011 SciRes. OJS

Page 12: Runs and Patterns in a Sequence of Markov Dependent ...file.scirp.org/pdf/OJS20110200006_34566710.pdfIn this paper we consider a sequence of Markov dependent bivariate trials whose

K. K. KAMALJA ET AL. 126

X 1 2, , , nX distribution of

2 2 21 2 21

, , , , ,, , ,

r rn k k n kY Y Y

using the method for de-

riving joint distribution of number of occurrences of pat-terns i 1, 2, ,i r in the

X . We obtain the joint

sequence of multi-state trials . For this consider the following transf ence of -variate sequence o

ndent t

,n

as dorm

-val

one by [11]ation of sequ

ued Markov depe m

rials f

2mS , 0iX i to the

f Ma dependent trials univariate se , 0

quence o.

rkov

i

Define the function 2 10: m m

Z ig S S such that

12m

i

1iig x x where

10S g nce 2

m mx x S . He

10 0,1,2, , 2 1mmS . Each x in 2

mS can be treated as a m -digit binary number. The function g x con-verts this m -digit binary number into a unique equiva-lent decimal number in 10

mS . Now corresponding to the m -variate sequence of

2mS -valued Markov dependent trials , 0iX i e , w

the univariate sequence -valued Markov ndent tri

havedepe

of 10Sm

als , 0iZ i where iiZ g X . The transition probabilities for the sequence of trials , 0iX i and

follows. for the converted sequence of trials

, 0iZ i are related as

1r r x yP X y X x P

P Z

where

1

2, , 1

r r ij

m

g y Z g x p

x y S r

g x i and g y j . Convert the pattern 2

1 2 ii i i ika a a 1,2, ,i r into atte a p rn 10

1 2 ii i i ikb b b where ijb g ija for

in t ce of

1, 2, ij . , kNow the original problem of studying the joint distribu-

tion of 2 2, rk

he sequen

2mS -valued Markov dependent trials

2 2 211

, , , , ,, , ,

rn k n n kY Y Y

1 2, , , nX X X problem of studying distribution of reduces to the

10 10 101 2 21

, , , , , ,, , ,

r rn k n k n kY Y Y

for the sequence of

10mS -valued Markov dependent trials 1 2, , , nZ Z Z . [15]

obtain e tion of number of occurrences of i -runs 0,1, 2, ,i m of length ik , while [11] ob-tain the joint distribution of num er of occurrences of p erns in the sequence of

th joint distribu

batt -valued M0,1, , m arkov

dependent trials using the method of conditional pgfs. d wa e distributions can also be studied The relate iting tim

fo cess as in Se e caMarkov dependent m ltivariate trials. 7. References

. quen

. 78

llowing the same pro ction 5 in thu

se of

[1] S J. Schwager, “Run Probabilities in Se ces of

Markov-Dependent Trials,” Journal of American Statis-tical Association, Vol , No. 381, 1983, pp. 168-175. doi:10.2307/2287125

N. Balakrishnan and P. S. Chan, “Start- tration Tests with Rejection of Units upon Observing d Fail-ures,” Annals of Institute of Statistic Mathematics, Vol. 52, No. 1, 2000, pp. 184-196.

[2] up Demons

al

doi:10.1023/A:1004101402897

ller, “An Introduction to Probability Theory and Its cations,” 3rd Edition, John

[3] W. FeAppli Wiley & Sons, Hoboken, 1968.

[4] K. D. Ling, “On Binomial Distributions of Order k,” Sta-tistics & Probability Letters, Vol. 6, No. 1988, pp. 247-250. doi:10.1016/0167-7152(88)90069-7

4,

[5] S. Aki and K. Hirano, “Number of Success-Runs of ecified Le til Certain

Generalized B nomial Distribu Annals of Institute o l Mathema l. 52, No. 4,

Sp ngth un Stopping Time Rules and i tions of Order k,”

f Statistica tics, Vo 2000, pp. 767-777. doi:10.1023/A:1017585512412

[6] A. M. Mood, “The Distribution Theory of Runs,” Annals Mathematical Statistics, Vol .

367-392. doi:10.1214/aoms/1177731825of . 11, No. 4, 1940, pp

g Timete Tri-

als,” Annals of Institute of s, Vol. 51, No. 1, 1999, pp. 17-29

[7] S. Aki and K. Hirano, “Sooner and Later Waitin Problems for Runs in Markov Dependent Bivaria

Statistical Mathematic.

doi:10.1023/A:1003874900507

[8] M. Uchida, “On Generating Functions of Waiting Time Problems for Sequence Patterns of Discrete Random Variables,” Annals of Institute of Statistical Mathematics, Vol. 50, No. 4, 1998, pp. 655-671. doi:10.1023/A:1003756712643

[9] D. L. Antzoulakos, “Waiting Times for Patterns in a Se-quence of Multistate Trials,” Journal of Applied Prob-ability, Vol. 38, No. 2, 2001, pp. 508-518. doi:10.1239/jap/996986759

[10] K. Inoue and S. Aki, “Genlems Associat

eralized Waiting Time Prob-ed with Pattern in Polya’s Urn Scheme,”

Annals of Institute of Statistical Mathematics, Vol. 54, No. 3, 2002, pp. 681-688. doi:10.1023/A:1022431631697

[11] K. S. Kotwal and R. L. Shinde, “Joint Distributions ofPatterns in the Seque

nce of Markov Dependent Multi-

, 2004, 169-182.

State Trials,” 2011 Submitted.

[12] S. Aki and K. Hirano, “Waiting Time Problems for a Two-Dimensional Pattern,” Annals of Institute of Statis-tical Mathematics, Vol. 56, No. 1doi:10.1007/BF02530530

[13] K. S. Kotwal and R. L. Shinde, “Joint Distributions of Runs in a Sequence of Higher-Order Two-State Markov trials,” Annals of Institute of Statistical Mathematics, Vol. 58, No. 1, 2006, pp. 537-554. doi:10.1007/s10463-005-0024-6

[14] A. A. Salvia and W. C. Lasher, “2-Dimensional Consecu-tive k-out-of-n: F Models,” IEEE Transactions on Reli-ability, Vol. R-39, No. 3, 1990, pp. 382-385. doi:10.1109/24.103023

Copyright © 2011 SciRes. OJS

Page 13: Runs and Patterns in a Sequence of Markov Dependent ...file.scirp.org/pdf/OJS20110200006_34566710.pdfIn this paper we consider a sequence of Markov dependent bivariate trials whose

K. K. KAMALJA ET AL.

Copyright © 2011 SciRes. OJS

127

ulti-[15] R. L. Shinde and K. S. Kotwal, “On the Joint Distribution

of Runs in the Sequence of Markov Dependent M 10, 2

State Trials,” Statistics & Probability Letters, Vol. 76, No.

006, pp. 1065-1074. doi:10.1016/j.spl.2005.12.005


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