A general theory on spectral properties of state-homogeneous finite-state quasi-birth-death process

Cataloged from PDF version of article.In this paper a spectral theory pertaining to Quasi-Birth±Death Processes (QBDs) is presented. The QBD, which is a generalization of the birth±death process, is a powerful tool that can be utilized in modeling many stochastic phenomena. Our theory is based on the application of a matrix polynomial method to obtain the steady-state probabilities in state-homogeneous ®nite-state QBDs. The method is based on ®nding the eigenvalue±eigenvector pairs that solve a matrix polynomial equation. Since the computational e ort in the solution procedure is independent of the cardinality of the counting set, it has an immediate advantage over other solution procedures. We present and prove di erent properties relating the quantities that arise in the solution procedure. By also compiling and formalizing the previously known properties, we present a formal uni®ed theory on the spectral properties of QBDs, which furnishes a formal framework to embody much of the previous work. This framework carries the prospect of furthering our understanding of the behavior the modeled systems manifest. Ó 2001 Elsevier Science B.V. All rights reserved

Supplier diversification under binomial yield

Cataloged from PDF version of article.We consider supplier diversification in an EOQ type inventory setting with multiple suppliers and binomial yields. We characterize the optimal policy for the model and show that, in this case, it does not pay to diversify, in contrast to previous results in the random yield literature. © 2008 Elsevier B.V. All rights reserved

A dynamic rationing policy for continuous-review inventory systems

Cataloged from PDF version of article.Stock rationing is an inventory policy that allows differential treatment of customer classes without using separate inventories. In this paper, we propose a dynamic rationing policy for continuous-review inventory systems, which utilizes the information on the status of the outstanding replenishment orders. For both backordering and lost sales environments, we conduct simulation studies to compare the performance of the dynamic policy with the static critical level and the common stock policies and quantify the gain obtained. We propose two new bounds on the optimum dynamic rationing policy that enables us to tell how much of the potential gain the proposed dynamic policy realizes. We discuss the conditions under which stock rationing – both dynamic and static – is beneficial and assess the value of the dynamic policy. 2009 Elsevier B.V. All rights reserved

Relationship between serum fatty acids and malondialdehyde (MDA) levels in coronary artery disease diagnosed (CAD) patients

Ed and Winnie Ola Berronghttps://dc.swosu.edu/barkpic07/1397/thumbnail.jp

Complementary therapies in palliative cancer care [Palyatif kanser bakiminda tamamlayici tedaviler]

PubMed ID: 16783665The use of complementary and alternative medicine (CAM) has grown in popularity both among the general population and among the cancer patients. Cancer patients often use CAM, which is a treatment that is not commonly used in the conventional setting. However, the prevalence of CAM use appears to vary substantially, with reported frequency of use of at least one CAM therapy ranging from 20% to 83-3%. Complementary medicine has become an important aspect of palliative cancer care. Acupuncture, aromatherapy, homeopaty, hypnotherapy, massage, reflexology, relaxation techniques, and spiritual healing are frequently used forms of treatment. The purpose of this article is to provide information about some complementary therapies that are commonly used by cancer patients in the palliative care

Erythropoietin exerts neuroprotection in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated C57/BL mice via increasing nitric oxide production

Erythropoietin (EPO), produced by the kidney and fetal liver, is a cytokine-hormone that stimulates erythropoiesis under hypoxic conditions. It has been shown that EPO is produced in the central nervous system and its receptor is expressed on neurons. Since EPO has neuroprotective effects in vitro and in vivo against brain injury, we investigated the effect of EPO treatment on locomotor activities of animals, survival of nigral dopaminergic neurons and nitrate levels in substantia nigra and striatum in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced animal model of Parkinsonism in C57/BL mice. Our findings suggest that EPO has protective and treating effect in MPTP-induced neurotoxicity in this mouse model of Parkinson's Disease via increasing nitric oxide production. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved