The uniformity of the WFC and HRC detector response has been assessed using multiple dithered pointings of 47 Tucanae. By placing the same stars over different portions of the detector and measuring relative changes in brightness, low frequency spatial variations in the response of each detector have been measured. The original WFC and HRC laboratory flat fields produce photometric errors of 6 ...

Ground calibration targets (GCTs) play a vital role in atmospheric correction of satellite sensor data in the optical region, but selecting suitable targets is a subjective and timeconsuming task. This paper describes a method to automatically select suitable GCTs, using a combination of remotely sensed multispectral and topographic data. Desirable characteristics for GCTs sites were identified...

MOTIVATION Data from one-channel cDNA microarray studies may exhibit poor reproducibility due to spatial heterogeneity, non-linear array-to-array variation and problems in correcting for background. Uncorrected, these phenomena can give rise to misleading conclusions. RESULTS Spatial heterogeneity may be corrected using two-dimensional loess smoothing (Colantuoni et al., 2002). Non-linear bet...

This paper proposes the use of tritium-activated light sources made up of CRT phosphors to act as transfer devices between reference spectroradiometers and CRT color measuring instruments. We describe the composition and characteristics of these sources and discuss their suitability as standards. We report on the laboratory measurement and testing of sources of similar nature obtained from a sa...

Pile scour may cause instability to the structures they support. Ensuring a safe and economically sound design is essential for the wider community. Although much laboratory research has been carried out on scour at pile groups, there are still significant gaps in prediction formulae. This study has been conducted to develop a formula for scour at pile arrangements of non-uniform spacing. The s...

The aim of this paper is to introduce and investigate α∗-uniformity on a nonempty set X using α∗-covers of X in L-fuzzy set theory. Equivalent conditions for α∗-uniformity and basis to α∗-uniformity, respectively, are obtained. The topology generated by α∗-uniformity, called α∗-topology, is also given. Various examples of α∗-uniformity on X are given and the α∗-topology induced by them are also...

I present arguments in favor of the Uniformity Hypothesis: the hypothesis that discourse can extend syntax dependencies without conflicting with them. I consider arguments that Uniformity is violated in certain cases involving quotation, and I argue that the cases presented in the literature are in fact completely consistent with Uniformity. I report on an analysis of all examples in the Copenh...

BACKGROUND AND PURPOSE VBM is increasingly used in the study of neurodegeneration, and recently there has been interest in its potential as a biomarker. However, although it is largely "automated," VBM is rarely implemented consistently across studies, and changing user-specified options can alter the results in a way similar to the very biologic differences under investigation. MATERIALS AND...

Magnetic resonance (MR) images can be acquired by multiple receiver coil systems to improve signal-to-noise ratio (SNR) and to decrease acquisition time. The optimal SNR images can be reconstructed from the coil data when the coil sensitivities are known. In typical MR imaging studies, the information about coil sensitivity profiles is not available. In such cases the sum-of-squares (SoS) recon...

Quality control (QC) is of primary importance for computed tomography systems to obtain reliable data for Non Destructive Testing (NDT). A QC protocol is pursued for the AIMEN dual detector CT by a software add-on update on the reconstruction and visualization software. Image quality parameters are considered following standards and other published papers: uniformity, noise, SNR, contrast, pixe...