Graphical diagnostics to check model misspecification for the proportional odds regression model

The cumulative logit or the proportional odds regression model is commonly used to study covariate effects on ordinal responses. This paper provides some graphical and numerical methods for checking the adequacy of the proportional odds regression model. The methods focus on evaluating functional misspecification for specific covariate effects, but misspecification of the link function can also be dealt with under the same framework. For the logistic regression model with binary responses, Arbogast and Lin ( Statist. Med. 2005; 24 :229–247) developed similar graphical and numerical methods for assessing the adequacy of the model using the cumulative sums of residuals. The paper generalizes their methods to ordinal responses and illustrates them using an example from the VA Normative Aging Study. Simulation studies comparing the performance of the different diagnostic methods indicate that some of the graphical methods are more powerful in detecting model misspecification than the Hosmer–Lemeshow-type goodness-of-fit statistics for the class of models studied. Copyright © 2008 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/61528/1/3386_ftp.pd

Estímulo no crescimento e na hidrólise de atp em raízes de alface tratadas com humatos de vermicomposto: ii - efeito da fonte de vermicomposto.

Um dos fatores mais limitantes para a produção de vermicomposto é a disponibilidade de esterco. Neste trabalho, foi avaliado o efeito da substituição parcial do esterco por bagaço de cana e por resíduos de leguminosa (Gliricidia sepium) na vermicompostagem sobre a qualidade do vermicomposto e sobre a bioatividade dos humatos, avaliadas por meio da análise do crescimento radicular e da atividade das bombas de H+ isoladas de raízes de alface. A substituição do esterco por bagaço de cana e por resíduos de leguminosas não acarretou prejuízo às características químicas dos vermicompostos. No entanto, os humatos isolados dos diferentes vermicompostos apresentaram características químicas distintas,tais como: acidez e propriedades óticas distintas. Os humatos produzidos a partir de esterco de bovino e da mistura esterco bovino + bagaço proporcionaram maiores estímulos no crescimento radicular das plantas de alface, sendo os mais indicados para uso na forma solúvel. A inclusão de resíduos de leguminosas no processo de vermicompostagem produziu humatos sem efeito sobre o desenvolvimento das raízes de alface

On the mechanism of superelasticity in Gum metal

The deformation mechanisms of the beta-Ti alloy, Gum metal, were investigated with the aid of in situ synchrotron X-ray diffraction (SXRD) and transmission electron microscopy (TEM). SXRD showed that Gum metal undergoes it reversible stress-induced martensitic (alpha '') phase transformation. Oxygen increases the resistance to shear by increasing C' and limits the extent of alpha '' growth. Prior deformation aids alpha '' formation of by providing nuclei, such as {112} twins and stress-induced omega plates. The formation of twins and omega plates, both observed in TEM, are believed to be a result of a low G(111) in this alloy. Features similar to the "giant faults" seen previously were observed in TEM their formation is believed to be a result of {112} shear. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved

THE SXDF-ALMA 2 arcmin² DEEP SURVEY:STACKING REST-FRAME NEAR-INFRARED SELECTED OBJECTS

We present stacking analyses on our ALMA deep 1.1 mm imaging in the SXDF using 1.6 {\mu}m and 3.6 {\mu}m selected galaxies in the CANDELS WFC3 catalog. We detect a stacked flux of ~0.03-0.05 mJy, corresponding to LIR < 10^11 Lsun and a star formation rate (SFR) of ~ 15 Msun/yr at z = 2. We find that galaxies brighter in the rest-frame near-infrared tend to be also brighter at 1.1 mm, and galaxies fainter than m[3.6um] = 23 do not produce detectable 1.1 mm emission. This suggests a correlation between stellar mass and SFR, but outliers to this correlation are also observed, suggesting strongly boosted star formation or extremely large extinction. We also find tendencies that redder galaxies and galaxies at higher redshifts are brighter at 1.1 mm. Our field contains z ~ 2.5 H-alpha emitters and a bright single-dish source. However, we do not find evidence of bias in our results caused by the bright source. By combining the fluxes of sources detected by ALMA and fluxes of faint sources detected with stacking, we recover a 1.1 mm surface brightness of up to 20.3 +/- 1.2 Jy/deg, comparable to the extragalactic background light measured by COBE. Based on the fractions of optically faint sources in our and previous ALMA studies and the COBE measurements, we find that approximately half of the cosmic star formation may be obscured by dust and missed by deep optical surveys, Much deeper and wider ALMA imaging is therefore needed to better constrain the obscured cosmic star formation history.Comment: accepted for publication in Ap

Analysis of the Performances of Biogas-Fuelled Micro Gas Turbine Cogeneration Systems (MGT-CGSs) in Middle- and Small-Scale Sewage Treatment Plants: Comparison of Performances and Optimization of Mgts with Various Electrical Power Outputs

The suitable size (electricity output capacity) of micro gas turbine cogeneration systems (MGT-CGSs) depending on scale of the sewage treatment plant was investigated. Since heat demand of the plant is affected by ambient temperature, performance under three typical ambient temperature conditions was investigated. Considering operation of the MGT-CGS under various loads and efficiency of the MGT-CGS under a partial load condition, the optimal combination of MGT-CGSs (MGT-Combination) with different sizes, 30 kW, 65 kW and 200 kW, was also proposed. An actual middle-scale plant was adopted as the analysis model, and it was scaled down to 0.50 and 0.25 in cases of smaller scale. Excluding MGT Combination, it was found that the MGT that has approximately the same fuel energy input under full load as the biogas energy produced in the plant has the highest efficiency. However, in the case of heat demand of the plant varying throughout the year such as the operation in a cold region, partial load operation will be frequent and efficiency will decrease. Furthermore, MGT-Combination has the highest efficiency but its efficiency will be the same as that of the other MGT-CGSs when only comparatively constant operation is required throughout the year such as operation in a tropical region