87,201 research outputs found
Impulse Response Confidence Intervals for Persistent Data: What Have We Learned?
No full textThis paper is a comprehensive comparison of existing methods for constructing confidence bands for univariate impulse response functions in the presence of high persistence. Monte Carlo results show that Kilian (1998a), Wright (2000), Gospodinov (2004) and Pesavento and Rossi (2005) have favorable coverage properties, although they differ in terms of robustness at various horizons, median unbiasedness, and reliability in the possible presence of a unit or mildly explosive root. On the other hand, methods like Runkle’s (1987) bootstrap, Andrews and Chen (1994), and regressions in levels or first differences (even when based on pre-tests) may not have accurate coverage properties. The paper makes recommendations as to the appropriateness of each method in empirical work.Local to unity asymptotics, persistence, impulse response functions
Impulse Response Confidence Intervals for Persistent Data: What Have We Learned?
No full textThis paper is a comprehensive comparison of existing methods for constructing confidence bands for univariate impulse response functions in the presence of high persistence. Monte Carlo results show that Kilian (1998a), Wright (2000), Gospodinov (2004) and Pesavento and Rossi (2005) have favorable coverage properties, although they differ in terms of robustness at various horizons, median unbiasedness, and reliability in the possible presence of a unit or mildly explosive root. On the other hand, methods like Runkleís (1987) bootstrap, Andrews and Chen (1994), and regressions in levels or first differences (even when based on pre-tests) may not have accurate coverage properties. The paper makes recommendations as to the appropriateness of each method in empirical work.Local to unity asymptotics, persistence, impulse response functions
Thermo-hygro-chemo-mechanical modeling of the behavior of a massive beam with restrained shrinkage
No full text
Supplemental Material, DS1_VET_10.1177_0300985818758470 - Amdoparvovirus Infection in Red Pandas (<i>Ailurus fulgens</i>)
No full textSupplemental Material, DS1_VET_10.1177_0300985818758470 for Amdoparvovirus Infection in Red Pandas (Ailurus fulgens) by Charles E. Alex, Steven V. Kubiski, Linlin Li, Mohammadreza Sadeghi, Raymund F. Wack, Megan A. McCarthy, Joseph B. Pesavento, Eric Delwart, and Patricia A. Pesavento in Veterinary Pathology</p
Modelling of non-isothermal decalcification of cement based composites
No full textW pracy przedstawiono model matematyczny i numeryczny zjawisk cieplno-wilgotnościowych i degradacji chemicznej kompozytów cementowych. Omówiono model kinetyki nieizotermicznego procesu dekalcyfikacji oraz przedstawiono wyniki symulacji procesu degradacji chemicznej płyty betonowej, na grubości której występuje gradient temperatury. Stwierdzono, że temperatura ma bardzo istotny wpływ na przebieg procesu dekalcyfikacji tej płyty.Mathematical and numerical model of hygro-thermal and chemical degradation phenomena of cement based composites, is briefly presented. A new model of non-isothermal decalcification kinetics is described. The results of computer simulation of chemical degradation of a concrete plate with a temperature gradient along its thickness, are presented and discussed. It is concluded that both temperature and the value and direction of temperature gradients have an important influence on the concrete chemical degradation due to decalcification process. The proposed method for modelling decalcification kinetics allows simulation of the process at variable temperature and avoiding numerical problems reported on the literature
A Multiphase Model for Concrete: Numerical Solutions and Industrial Applications
No full textA mathematical and numerical model to predict the non-linear behaviour of concrete as multiphase porous material is proposed. The model can be usefully applied to several practical cases: evaluation of concrete performance in the high temperature range, e.g. during fire, to early stages of maturing of massive concrete structures, to shotcrete in tunnelling, and to durability. All the important phase changes of water and chemical reactions, i.e. adsorption-desorption, condensation-evaporation, and hydration-dehydration, as well as the related heat and mass sources or sinks are considered. Changes of the material properties caused by temperature and pressure changes, concrete damage or carbonation, fresh concrete hardening, as well as coupling between thermal, hygral and mechanical phenomena are taken into account. This model further allows to incorporate sorption hysteresis. Some relevant applications of the model will be shown in this work
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