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Shift Patterns (shift + pattern)

Distribution by Scientific Domains

Chemistry	50%

Selected Abstracts

Determination of lattice-transform density profiles for multilayered three-dimensional microcrystals in electron crystallography

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 4 2000
Eva Dimmeler
Electron crystallography on multilayered three-dimensional microcrystals has been limited in application by the need to define precisely the three-dimensional shape of the diffraction density profiles. A new method is presented here to obtain this profile from experimental spot positions which are shifted in a characteristic way from the expected Bragg positions. While the Bragg positions are defined by the diffraction geometry, the characteristic shift additionally depends on the density profile in Fourier space. In general, these two effects are intermingled. A new correlation approach is presented which uses characteristic shift patterns to separate these effects. This technique also allows the determination of all three crystallographic unit-cell dimensions from a single tilted electron diffraction pattern. It was tested on simulated diffraction patterns and applied to experimental data of frozen hydrated crystals of the protein catalase. Since multilayered catalase crystals with different numbers of crystallographic layers were studied, an inhomogeneous data set had to be evaluated. Processing of such data is now possible using the new correlation approach. [source]

Shifted factor analysis,Part III: N -way generalization and application

JOURNAL OF CHEMOMETRICS, Issue 7 2003
Sungjin Hong
Abstract The ,quasi-ALS' algorithm for shifted factor estimation is generalized to three-way and n -way models. We consider the case in which mode A is the only shifted sequential mode, mode B determines shifts, and modes above B simply reweight the factors. The algorithm is studied using error-free and fallible synthetic data. In addition, a four-way chromatographic data set previously analyzed by Bro et al. (J. Chemometrics 1999; 13: 295,309) is reanalyzed and (two or) three out of four factors are recovered. The reason for the incomplete success may be factor shape changes combined with the lack of distinct shift patterns for two of the factors. The shifted factor model is compared with Parafac2 from both theoretical and practical points of view. Copyright © 2003 John Wiley & Sons, Ltd. [source]

Twelve-hour shift on ITU: a nursing evaluation

NURSING IN CRITICAL CARE, Issue 3 2003
Annette Richardson
Summary ,This paper describes the introduction and subsequent evaluation of a 12-h shift system in a large ITU in the northeast of UK ,To date, only a small number of studies has evaluated nurses working the 12-h shifts in critical care areas ,To evaluate the level of staff satisfaction, data were collected by means of a questionnaire involving 41 nurses, at 3 months following the introduction of the 12-h shifts ,The responses from the evaluation advocated the continuation of 12-h shifts with alternative shift patterns for nurses who felt dissatisfied with the current system ,Twelve-hour shifts can be seen as a flexible system for nurses working in intensive care and may assist with staff satisfaction and improving nurse recruitment and retention [source]

Using Profile Monitoring Techniques for a Data-rich Environment with Huge Sample Size

QUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 7 2005
Kaibo Wang
Abstract In-process sensors with huge sample size are becoming popular in the modern manufacturing industry, due to the increasing complexity of processes and products and the availability of advanced sensing technology. Under such a data-rich environment, a sample with huge size usually violates the assumption of homogeneity and degrades the detection performance of a conventional control chart. Instead of charting summary statistics such as the mean and standard deviation of observations that assume homogeneity within a sample, this paper proposes charting schemes based on the quantile,quantile (Q,Q) plot and profile monitoring techniques to improve the performance. Different monitoring schemes are studied based on various shift patterns in a huge sample and compared via simulation. Guidelines are provided for applying the proposed schemes to similar industrial applications in a data-rich environment. Copyright © 2005 John Wiley & Sons, Ltd. [source]