True Size (true + size)

Distribution by Scientific Domains


Selected Abstracts


New dimensions in endodontic imaging: Part 2.

INTERNATIONAL ENDODONTIC JOURNAL, Issue 6 2009
Cone beam computed tomography
Abstract Cone beam computed tomography (CBCT) has been specifically designed to produce undistorted three-dimensional information of the maxillofacial skeleton, including the teeth and their surrounding tissues with a significantly lower effective radiation dose compared with conventional computed tomography (CT). Periapical disease may be detected sooner using CBCT compared with periapical views and the true size, extent, nature and position of periapical and resorptive lesions can be assessed. Root fractures, root canal anatomy and the nature of the alveolar bone topography around teeth may be assessed. The aim of this paper is to review current literature on the applications and limitations of CBCT in the management of endodontic problems. [source]


Optimal Monetary Policy with an Uncertain Cost Channel

JOURNAL OF MONEY, CREDIT AND BANKING, Issue 5 2009
PETER TILLMANN
parameter uncertainty; min,max; cost channel; optimal monetary policy; Taylor rule The cost channel of monetary transmission describes a supply-side effect of interest rates on firms' costs. Previous research has found this effect to vary, both over time and across countries. Moreover, the cyclical nature of financial frictions is likely to amplify the cost channel. This paper derives optimal monetary policy in the presence of uncertainty about the true size of the cost channel. In a min,max approach, the central bank derives an optimal policy plan to be implemented by a Taylor rule. It is shown that uncertainty about the cost channel leads to an attenuated interest rate setting behavior. In this respect, the Brainard (1967) principle of cautious policy in the face of uncertainty continues to hold in both a Bayesian and a min,max framework. [source]


Novel Sample Preparation Method of Polymer Emulsion for SEM Observation

MICROSCOPY RESEARCH AND TECHNIQUE, Issue 10 2007
Jing Xu
Abstract The aim of this study was to design a simple and reliable method for obtaining the detailed information about the average size, size distribution, and the surface morphology of particles with variation of the sample preparation of a polymer emulsion. In this work, the characteristic features of the particles of rosin size with high viscosity were first described by scanning electron microscopy (SEM). The morphologies of polymer emulsion of solid lipid nanoparticles and of the microspheres were observed. The advantage of the method is that not only the true size and shape of emulsion particles can be shown, but the problem of high-viscosity emulsion that prevents there study with SEM is solved. Using this new method, the micromorphology and size distribution of the emulsion particles with different viscosities have been clearly observed. Microsc. Res. Tech., 2007. © 2007 Wiley-Liss, Inc. [source]


Testing for stationarity in heterogeneous panel data

THE ECONOMETRICS JOURNAL, Issue 2 2000
Kaddour Hadri
This paper proposes a residual-based Lagrange multiplier (LM) test for a null that the individual observed series are stationary around a deterministic level or around a deterministic trend against the alternative of a unit root in panel data. The tests which are asymptotically similar under the null, belong to the locally best invariant (LBI) test statistics. The asymptotic distributions of the statistics are derived under the null and are shown to be normally distributed. Finite sample sizes and powers are considered in a Monte Carlo experiment. The empirical sizes of the tests are close to the true size even in small samples. The testing procedure is easy to apply, including, to panel data models with fixed effects, individual deterministic trends and heterogeneous errors across cross-sections. It is also shown how to apply the tests to the more general case of serially correlated disturbance terms. [source]


Sample Size Determination for Establishing Equivalence/Noninferiority via Ratio of Two Proportions in Matched,Pair Design

BIOMETRICS, Issue 4 2002
Man-Lai Tang
Summary. In this article, we propose approximate sample size formulas for establishing equivalence or noninferiority of two treatments in match-pairs design. Using the ratio of two proportions as the equivalence measure, we derive sample size formulas based on a score statistic for two types of analyses: hypothesis testing and confidence interval estimation. Depending on the purpose of a study, these formulas can be used to provide a sample size estimate that guarantees a prespecified power of a hypothesis test at a certain significance level or controls the width of a confidence interval with a certain confidence level. Our empirical results confirm that these score methods are reliable in terms of true size, coverage probability, and skewness. A liver scan detection study is used to illustrate the proposed methods. [source]