38 research outputs found

    Optimal Multi-Modes Switching Problem in Infinite Horizon

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    This paper studies the problem of the deterministic version of the Verification Theorem for the optimal m-states switching in infinite horizon under Markovian framework with arbitrary switching cost functions. The problem is formulated as an extended impulse control problem and solved by means of probabilistic tools such as the Snell envelop of processes and reflected backward stochastic differential equations. A viscosity solutions approach is employed to carry out a finne analysis on the associated system of m variational inequalities with inter-connected obstacles. We show that the vector of value functions of the optimal problem is the unique viscosity solution to the system. This problem is in relation with the valuation of firms in a financial market

    Calculated Electronic Energy Loss of Heavy Ions at Low Energies in LR-115, Kapton, SiO2, and Al2O3 Amorphous Materials

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    The electronic stopping powers of LR-115 and Kapton polymeric foilshave been estimated, using Monte Carlo simulations, for 9Be, 11B, 12C, 14N, 16O, and 35Cl ions covering the energy range ~0.1-1.0 MeV/n. Comparison of stopping power based on Lindhard, Scharff, and Schiott (LSS) theory with the corresponding values obtained by SRIM and MSTAR codes in LR-115 and Kapton polymeric foils illustrate a significantly large deviations. However, a semiempirical equation has been proposed here and tested for better stopping power calculations at low-energy regime in the domain of LSS theory for Z = 4-8 ions across materials. Furthermore, the electronic energy losses for 9Be and 16O ions in SiO2 and Al2O3, respectively, have been calculated in the energy range of ~0.1-1.0 MeV/n. The calculated stopping powers exhibit up to 10 % deviation from the experimental values and MSTAR data

    Viscosity solutions of systems of PDEs with interconnected obstacles and Multi modes switching problems

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    This paper deals with existence and uniqueness, in viscosity sense, of a solution for a system of m variational partial differential inequalities with inter-connected obstacles. A particular case of this system is the deterministic version of the Verification Theorem of the Markovian optimal m-states switching problem. The switching cost functions are arbitrary. This problem is connected with the valuation of a power plant in the energy market. The main tool is the notion of systems of reflected BSDEs with oblique reflection.Comment: 36 page

    Maternal Characteristics and Clinical Diagnoses Influence Obstetrical Outcomes in Indonesia

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    This Indonesian study evaluates associations between near-miss status/death with maternal demographic, health care characteristics, and obstetrical complications, comparing results using retrospective and prospective data. The main outcome measures were obstetric conditions and socio-economic factors to predict near-miss/death. We abstracted all obstetric admissions (1,358 retrospective and 1,240 prospective) from two district hospitals in East Java, Indonesia between 4/1/2009 and 5/15/2010. Prospective data added socio-economic status, access to care and referral patterns. Reduced logistic models were constructed, and multivariate analyses used to assess association of risk variables to outcome. Using multivariate analysis, variables associated with risk of near-miss/death include postpartum hemorrhage (retrospective AOR 5.41, 95 % CI 2.64–11.08; prospective AOR 10.45, 95 % CI 5.59–19.52) and severe preeclampsia/ eclampsia (retrospective AOR 1.94, 95 % CI 1.05–3.57; prospective AOR 3.26, 95 % CI 1.79–5.94). Associations with near-miss/death were seen for antepartum hemorrhage in retrospective data (AOR 9.34, 95 % CI 4.34–20.13), and prospectively for poverty (AOR 2.17, 95 % CI 1.33–3.54) and delivering outside the hospital (AOR 2.04, 95 % CI 1.08–3.82). Postpartum hemorrhage and severe preeclampsia/ eclampsia are leading causes of near-miss/death in Indonesia. Poverty and delivery outside the hospital are significant risk factors. Prompt recognition of complications, timely referrals, standardized care protocols, prompt hospital triage, and structured provider education may reduce obstetric mortality and morbidity. Retrospective data were reliable, but prospective data provided valuable information about barriers to care and referral patterns

    Prospective Observational Study on acute Appendicitis Worldwide (POSAW)

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    Acute appendicitis (AA) is the most common surgical disease, and appendectomy is the treatment of choice in the majority of cases. A correct diagnosis is key for decreasing the negative appendectomy rate. The management can become difficult in case of complicated appendicitis. The aim of this study is to describe the worldwide clinical and diagnostic work-up and management of AA in surgical departments.info:eu-repo/semantics/publishedVersio

    Faux anévrisme artériel traumatique intracrânien

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    Nous rapportons un cas d'anévrysme post-traumatique de l'artère carotide interne chez un enfant de 11 ans, ayant présenté une ophtalmoplégie droite. Un faux anévrisme de la carotide interne droite a été diagnostiqué par angiographie cérébrale. Le malade a bénéficié d'un traitement endovasculaire et l'évolution fut favorable. Malgré leur rareté, le diagnostic des anévrysmes post traumatiques devrait être évoqué chez tout traumatisé crânien en cas d'aggravation clinique secondaire, afin de réaliser une exploration  angiographique avant d'envisager un traitement radical soit chirurgical soit par voie endovasculaire

    Inter-Diffusion of cobalt and silicon through an ultrathin aluminum oxide layer

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    International audienceOptical emission spectroscopy of sputtered species during ion bombardment, Auger electron spectroscopy and high-resolution transmission electron microscopy were used to study the cobalt and silicon diffusion through the interfaces of Co/AlO/Si(0 0 1) hetero-structure. The results are discussed as a function of the annealing temperature of sample and show that the diffusion process at the interfaces starts for annealing temperatures above 200 °C without detectable modification of the oxide layer
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