Determination of the Joint Confidence Region of Optimal Operating Conditions in Robust Design by Bootstrap Technique

Robust design has been widely recognized as a leading method in reducing variability and improving quality. Most of the engineering statistics literature mainly focuses on finding "point estimates" of the optimum operating conditions for robust design. Various procedures for calculating point estimates of the optimum operating conditions are considered. Although this point estimation procedure is important for continuous quality improvement, the immediate question is "how accurate are these optimum operating conditions?" The answer for this is to consider interval estimation for a single variable or joint confidence regions for multiple variables. In this paper, with the help of the bootstrap technique, we develop procedures for obtaining joint "confidence regions" for the optimum operating conditions. Two different procedures using Bonferroni and multivariate normal approximation are introduced. The proposed methods are illustrated and substantiated using a numerical example.Comment: Two tables, Three figure

Unusual Ground State Properties of the Kondo-Lattice Compound Yb2Ir3Ge5

We report sample preparation, structure, electrical resistivity, magnetic susceptibility and heat capacity studies of a new compound Yb$_2$Ir$_3$Ge$_5$. We find that this compound crystallizes in an orthorhombic structure with a space group PMMN unlike the compound Ce$_2$Ir$_3$Ge$_5$ which crystallizes in the tetragonal IBAM (U$_2$Co$_3$Si$_5$ type) structure. Our resistivity measurements indicate that the compound Yb$_2$Ir$_3$Ge$_5$ behaves like a typical Kondo lattice system with no ordering down to 0.4 K. However, a Curie-Weiss fit of the inverse magnetic susceptibility above 100 K gives an effective moment of only 3.66 $\mu$$_B$ which is considerably less than the theoretical value of 4.54 $\mu$$_B$ for magnetic Yb$^3+$ ions. The value of $\theta_{P}$ = -15.19 K is also considerably higher indicating the presence of strong hybridization. An upturn in the low temperature heat capacity gives an indication that the system may order magnetically just below the lowest temperature of our heat capacity measurements (0.4 K). The structure contains two sites for Yb ions and the present investigation suggests that Yb may be trivalent in one site while it may be significantly lower (close to divalent) in the other.Comment: 9 pages, 4 figures. submitted to Phys. Rev.

Antiferromagnetic ordering in the Kondo lattice system Yb2_2Fe3_3Si5_5

Compounds belonging to the R$_2$Fe$_3$Si$_5$ series exhibit unusual superconducting and magnetic properties. Although a number of studies have been made on the first reentrant antiferromagnet superconductor Tm$_2$Fe$_3$Si$_5$, the physical properties of Yb$_2$Fe$_3$Si$_5$ are largely unexplored. In this work, we attempt to provide a comprehensive study of bulk properties such as, resistivity, susceptibility and heat-capacity of a well characterized polycrystalline Yb$_2$Fe$_3$Si$_5$. Our measurements indicate that Yb$^{3+}$ moments order antiferromagnetically below 1.7 K. Moreover, the system behaves as a Kondo lattice with large Sommerfeld coefficient ($\gamma$) of 0.5~J/Yb mol K$^{2}$ at 0.3 K, which is well below T$_N$. The absence of superconductivity in Yb$_2$Fe$_3$Si$_5$ down to 0.3 K at ambient pressure is attributed to the presence of the Kondo effect.Comment: 10 pages, 3 figures, tex document. A fuller version has appeared in PRB. Here we have omitted the figures showing the crystal structure and the fitting of the X-ray pattern. Also the table with the lattice parameters obtained from fitting has been remove

Field-induced water electrolysis switches an oxide semiconductor from an insulator to a metal

Here we demonstrate that water-infiltrated nanoporous glass electrically switches an oxide semiconductor from an insulator to metal. We fabricated the field effect transistor structure on an oxide semiconductor, SrTiO3, using 100%-water-infiltrated nanoporous glass - amorphous 12CaO*7Al2O3 - as the gate insulator. For positive gate voltage, electron accumulation, water electrolysis and electrochemical reduction occur successively on the SrTiO3 surface at room temperature, leading to the formation of a thin (~3 nm) metal layer with an extremely high electron concentration of 10^15-10^16 cm^-2, which exhibits exotic thermoelectric behaviour.Comment: 21 pages, 12 figure

The Impact of Community Use of Novel Oral Anticoagulants on an Academic Medical Center

Warfarin has been a mainstay of therapy for treatment and prevention of venous thromboembolic disease (VTED) and prevention of stroke and systemic embolism for over 50 years. Recent FDA approval of several novel oral anticoagulants has offered more extensive treatment options for management of these disease states. The availability of the novel anticoagulants offers an attractive alternative to warfarin therapy for patients due to their convenience of use. In comparison to warfarin, dabigatran, rivaroxaban and apixaban offer: - a fixed dosage regimen - a relatively small potential drug interaction profile - minimal laboratory monitoring - little to no dietary restrictions. Although these agents offer a relatively fixed dose regimen, dosage adjustment is required in moderate renal dysfunction, and use is contraindicated in severe renal dysfunction. Currently there are no specific reversal agents in the event of a nov- el anticoagulant associated bleed. These concerns led to the development of an anticoagulation stewardship program at our institution to monitor and guide the usage of these agents