Bayesian sequential estimation of the reliability of a parallel-series system

We give a risk-averse solution to the problem of estimating the reliability of a parallel-series system. We adopt a beta-binomial model for components reliabilities, and assume that the total sample size for the experience is fixed. The allocation at subsystems or components level may be random. Based on the sampling schemes for parallel and series systems separately, we propose a hybrid sequential scheme for the parallel-series system. Asymptotic optimality of the Bayes risk associated with quadratic loss is proved with the help of martingale convergence properties.Comment: 12 page

Literatura marroquí sobre el protectorado: relación entre la colonia y los autóctonos

Resumen: El artículo  abarca la geografía y la idiosincrasia marroquíes durante una de las etapas críticas de Marruecos; y de la relación y condiciones humanas entre los colonos y los autóctonos: La ocupación colonial por dos países europeos desde 1912 hasta 1956: España, en el norte y extremo sur y Francia en el  centro  y  sur.   Durante  el  Protectorado  la  literatura  en  lengua  árabe  ocupa  un  lugar  de  vital importancia  en  el  desarrollo  de  la  cultura  del  país. La cultura  árabe  fue  considerada  como  un instrumento educativo de primer orden para la edificación del nacionalismo, el mantenimiento de la religión islámica y la toma de conciencia del pueblo de su realidad. La literatura en lengua árabe en Marruecos ha conocido un progreso importante en el siglo XX. Anteriormente se encasillaba en canciones, poesía y en artículos sobre historia, geografía o partes de guerra. La escritura de expresión francesa y española domina también importantes áreas del saber de Marruecos. Este trabajo muestra las varias instituciones y profesiones que van a entrar en la dinámica de la demanda de Independencia durante este periodo; como lo son la prensa, el teatro y el impacto social de novelas y cuentos. Palabras clave: Cultura marroquí, Islam, cultura árabe, protectorado francés y español, colonialismo, interculturalidad, historia siglo xx, literatura, prensa, teatro Abstract: The article covers the geography and Moroccan idiosyncrasies during one of the critical stages in Morocco, and the human condition and relationship between settlers and indigenous: the colonial occupation by two European countries from 1912 to 1956: Spain, in the north and extreme south and France in the center and south. During the Protectorate literature in Arabic occupies a place of vital importance in the development of the country's culture. Arab culture was regarded as one of the educational tools of first order for the construction of nationalism, maintaining the Islamic religion and awareness of the people of their reality. The literature in Arabic in Morocco has seen a significant progress in the twentieth century. Previously it was pigeonholed in songs, poetry and articles on the history, geography or war reports. Writing in French and Spanish also dominates -but in a much lesser extent- important knowledge areas of Morocco. This work shows the various institutions and professions who will get into the dynamics of the demand for independence during this period, such as the press, the theater and the social impact of novels and short stories. Keywords: Moroccan culture, Islam, Arab culture, French and Spanish protectorate, colonialism, multiculturalism, twentieth-century history, literature, news, thea

Asymptotic Optimality of Experimental Designs in Estimating a Product of Means

In nonlinear estimation problems with linear models, one difficulty in obtaining optimal designs is their dependence on the true value of the unknown parameters. A Bayesian approach is adopted with the assumption the means are independent apriori and have conjuguate prior distributions. The problem of designing an exper- iment to estimate the product of the means of two normal populations is considered. The main results determine an asymptotic lower bound for the Bayes risk, and a necessary and sufficient condition for any sequential procedure to achieve the bound

Structural properties and new phase transitions of silver iodide using the FP-LMTO method

We report first principles calculations of structural and electronic, properties of AgI compound in zinc blende(B3), CsCl(B2), rocksalt(B3), wirtzait(B4), NiAs(B8_1), PbO(B10), HCP(A3) and βSn(A5) structures employing the density functional theory (DFT) within the local density approximation (LDA) and the generalized gradient approximation (GGA). We employ the full potential linear muffin-tin orbitals (FP-LMTO) as implemented in the Lmtart code. Results are given for lattice parameters, bulk modulus and its first derivatives in the differents structures. The most important result in this work, the prediction of the possibility of two phase transitions; the firste ; from cubic rocksalt (NaCl)→ hexagonal HCP(A3) (55.58 GPa) and the second ; from rocksalt (NaCl)→ CsCl (B2) (68.78GPa) for AgBr. The silver halides in particular the silver Iodide AgI, they have different applications in photographic processes [1,2], holography [3], photo and electro chemistry [4], catalysis [5-6], as liquid semiconductors [7], etc. In photochemical applications. AgI crystallize in the rock salt structure at room temperature. However their electronic structure is more complicated than the alkali halides. As Kunz [8]. Many investigations different of physical properties of the binary compounds under hydrostatic pressure have been an active topic of research in condensed matter over the past few years. At high pressures semiconductors study is an exceptionally good tool in understanding their optoelectronic properties but these studies have been scarcely used in the investigation of AgI, as compared to other I-VII semiconductors. At the end of last decade Hull and Keen [15] performed X-ray diffraction (XRD) studies of AgBr, AgCl and AgI correspond to the rocksalt structure and they exhibit transitions to cesium chloride and/or other phases upon the influence of external pressure. Theorical, calculations has been realized [24] in three main structures (B2, B1 and B3) for AgCl, four structures (B1, B2, B3 and B8_1) for AgBr, and five geometries (B1, B2, B3, B8_1 and B4

Single-Visit Pulp Revascularization of a Nonvital Immature Permanent Tooth Using Biodentine

An 11-year-old female patient was referred with a chief complaint of pain in the right mandibular second premolar. Clinical and radiographic examinations showed secondary caries under an old composite restoration, a negative response to a pulp test and an immature root with an open apex. After root canal cleaning and shaping, bleeding was invoked in the canal up to 2 mm short of the cemento-enamel junction (CEJ). After 10 min to allow clotting at this level, a plug of Biodentine was placed over the blood clot and the tooth was temporized with glass ionomer cement. At the next visit, the tooth was free of symptoms and a permanent filling was placed. Clinical and radiographic examinations during a two-year follow-up showed complete root maturation and intact supporting soft tissues without sinus tract, pain or swelling. Conclusion: The use of Biodentine in a single-visit apexification protocol to treat an immature permanent tooth with necrotic pulp can create a suitable environment for revascularization, resulting in the completion of root maturation.Key Words:Biodentine; Immature Apex; Pulp Revascularization