A useful generalization of renewal theory: counting processes governed by non-negative Markovian increments

M Kijima, U Sumita - Journal of Applied probability, 1986 - cambridge.org
Let N(t) be a counting process associated with a sequence of non-negative random variables
(Xj)1∞ where the distribution of Xn+1 depends only on the value of the partial sum Sn = Σj=…

General shock models associated with correlated renewal sequences

JG Shanthikumar, U Sumita - Journal of Applied Probability, 1983 - cambridge.org
… where W~O)(t) = U(t) is the ordinary unit step function at the origin. Let gz (t, u) be the …
Let U, (t) be the number of upcrossings caused by the correlated renewal process over level …

Uniform stochastic ordering and related inequalities

J Keilson, U Sumita - Canadian Journal of Statistics, 1982 - Wiley Online Library
… The ordering is local when it holds for any finite interval (u, b), however small. Local order
in multivariate settings has been described by Whitt (1980, 1981), by Karlin and Rinott (1980), …

Importance of policy for energy system transformation: Diffusion of PV technology in Japan and Germany

S Chowdhury, U Sumita, A Islam, I Bedja - Energy policy, 2014 - Elsevier
Photovoltaic (PV) has the highest cost reduction potential among all renewable energy
sources (RES). To overcome institutional barriers, developing the technology, and creating an …

A class of correlated cumulative shock models

U Sumita, JG Shanthikumar - Advances in Applied probability, 1985 - cambridge.org
… Shanthikumar and Sumita [12] have established sufficient … sufficient conditions of Shanthikumar
and Sumita [12] are satisfied … AND SUMITA, U. (1984) A central limit theorem for random …

Enhancement of e-commerce via mobile accesses to the Internet

U Sumita, J Yoshii - Electronic commerce research and applications, 2010 - Elsevier
… ̲ 6 T 0 ̲ T + ζ ˆ ̲ ̲ ( 0 + , s ) γ ̲ ̲ ( s ) , where u ̲ i is the ith unit vector in R 8 and(3.34) γ
̲ ̲ ( s ) = 0 0 ̲ T 0 ξ ̲ ˆ ( s ) B ̲ ̲ ( s ) θ ̲ ˆ ( s ) 0 0 ̲ T 0 , with(3.35) B ̲ ̲ ( s ) = 0 α W ( s …

Distribution properties of the system failure time in a general shock model

JG Shanthikumar, U Sumita - Advances in Applied Probability, 1984 - cambridge.org
… It has been shown by Shanthikumar and Sumita [16] that the system failure time T; has the …
For this model Shanthikumar and Sumita [16] have shown the following results corresponding …

Approximations for the time spent in a dynamic job shop with applications to due-date assignment

JG Shanthikumar, U Sumita - The International Journal of …, 1988 - Taylor & Francis
In this paper we develop approximations for the distribution of the total time spent in a dynamic
job shop. In particular, using an exponential limit theorem and an heuristic decomposition …

A central limit theorem for random sums of random variables

JG Shanthikumar, U Sumita - Operations research letters, 1984 - Elsevier
Anscombe (1952) (also see Chung (1974)) has developed a central limit theoremof random
sums of independent and identically distributed random variables. Applicability of this …

Lumpability and time reversibility in the aggregation-disaggregation method for large Markov chains

U Sumita, M Rieders - Stochastic Models, 1989 - Taylor & Francis
… Let N(t) be a continuous time finite Markov chain on U governed by v. - Then there exists u
> 0 such that N(t) is ergodic if and only if the discrete time Markov chain J(k) on U governed by …