Reconstruction artifact

Helical pitch <1 ( high-speed helical techniques produce unacceptable reconstruction artifacts in the posterior fossa) Slow table speed (8-11 mm/s) Rapid gantry rotation (0.5-0.8 rotations/s) Smallest possible focal spot setting ... 

Losses in phylogenetic information may arise from mutation saturation, lateral gene transfer and a reconstruction artifact, long branch attraction phenomenon (Brown and Doolittle, 1997 Philippe and Laurent, 1998). 

Brinckmann, H. and Philippe, H. (1999) Archaea sister group of bacteria. Indications for tree reconstruction artifacts in ancient phylogenies , Molecular Biology and Evolution, 16, 817-25. 

Restrictions for a curve of source movement reffer to as a completeness condition. This condition determines whether the information that is contained within some geometry of cone vertices is enough to perform an artifact-free reconstruction. 

Are these off-centering real or due to an artifact of the reconstruction The fact that they occur the same way on two unequivalent molecules is already an indication. The best way to completely answer the question is to reconstruct the spin density with a MaxEnt method and a non-uniform prior, a prior in which the density is centered on the nuclei. We have done this reconstruction, taking as a prior for the two molecules the averaged parametrized spin density refined above. The result is shown in Figure 7. The off-centering of the Nl-Ol density and of the negative Cl density is still there, even at the price of a loss of entropy, as it departs from the model. 

The result of the PAM reconstruction is, in general, only an approximation of the exit wave function. Some non-linear terms may be present exactly on the paraboloid surfaces, and, thus result in artifacts for the PAM reconstruction. However, the PAM result is a good approximation to the exit wave function, which, in the present implementation, is used as a starting point for a maximum likelihood (MAL) reconstruction that takes the non-linear image contributions fully into account (Coene et al. 1996, Thust etal. 1996a). 

Marine shell beads are a regular component of the Holocene archaeological record in many areas of the world. Although they rarely outnumber more common artifacts, such as flaked stone and ceramics, they are sufficiently ubiquitous to have been the subject of considerable archaeological research. Such studies focused on both the symbolic aspects of beads (e.g., wealth display) and the reconstruction of prehistoric trade and/or exchange systems. 

Non-perfect reconstruction The passband ripple which is typical for QMF filter designs can lead to time domain artifacts which can be audible even if they are at very low amplitudes. 

Phase 2 - data preprocessing. There are many ways to process spectral data prior to multivariate image reconstruction and there is no ideal method that can be generally applied to all types of tissue. It is usual practice to correct the baseline to account for nonspecific matrix absorptions and scattering induced by the physical or bulk properties of the dehydrated tissue. One possible procedure is to fit a polynomial function to a preselected set of minima points and zero the baseline to these minima points. However, this type of fit can introduce artifacts because baseline variation can be so extreme that one set of baseline points may not account for all types of baseline variation. A more acceptable way to correct spectral baselines is to use the derivatives of the spectra. This can only be achieved if the S/N of the individual spectra is high and if an appropriate smoothing factor is introduced to reduce noise in the derivatized spectra. Derivatives serve two purposes they minimize broad... 

Tears are repaired with Japanese tissue, missing areas are filled in with paper similar to the artifact. Repair paper of specific caliper and tone is made in the leaf caster. Adhesives vary methyl cellulose, wheat paste, or a mixture of polyvinyl alcohol with rice paste. The mixture is most useful because it permits use of a warm tacking iron to hasten the drying process. Where missing areas have been patched, the restorer reconstructs only those lines and colors that are already discernable, lest the work be called an attempt at falsification. 

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