Analysis of the Au 4f ESCA spectra of thin gold films deposited over a graphite base shows that as the separation from the main photoelectron peak, ΔE, increases the background decreases. Conversely, the effect of a ...
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Analysis of the Au 4f ESCA spectra of thin gold films deposited over a graphite base shows that as the separation from the main photoelectron peak, ΔE, increases the background decreases. Conversely, the effect of a contaminant overlayer on solid gold gives rise to a background which increases as ΔE increases. There is, therefore, a considerable variety of background profiles which can be encountered in real samples, which depends markedly on the element, its concentration, and its distribution in the sample. Over the region of the photoelectron line signal itself, the simple integral description which assumes that the background is proportional to the number of electrons of higher kinetic energy is reasonably valid and is suggested for peak area measurement when a nonlinear profile is *** integration and curve fitting techniques constitute the two main methods of peak area measurement. Simulated Ni 2p spectra are used to compare the effectiveness of the simple integral and linear background profiles for producing the correct peak areas. Although the simple integral profile shows more consistency and is to be preferred in general, certain fortuitous cancellation effects, particularly with non-monochromatized spectra, make areas using the linear background fairly accurate in some instances. Curve fitting can overcome many of the problems of direct integration resulting from severe peak overlap. Two types of Gaussian/Lorentzian functions with a suitable exponential tailing function, which has a finite area over reasonable integration limits, are discussed with regard to their use in non-linear least-squares curve fitting methods. Also discussed is the usefulness of composite and difference spectra as simpler methods of determining the relative areas of overlapping peaks.
The increasing difficulties in testing large logic networks have generated the need for designing logic networks for testability. computer algorithms for designing diagnosable metal oxide semiconductor (MOS) networks ...
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The increasing difficulties in testing large logic networks have generated the need for designing logic networks for testability. computer algorithms for designing diagnosable metal oxide semiconductor (MOS) networks with and without fan-in, fan-out constraints were described in previous papers by the authors. In this two-part series, we discuss the testing of these designed networks.
Cell sorting and tritiated thymidine autoradiography were used to define the distribution of S phase cells in flow cytometric DNA histograms obtained from exponential mouse lymphoma cells (L5178Y). The numbers of labe...
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Cell sorting and tritiated thymidine autoradiography were used to define the distribution of S phase cells in flow cytometric DNA histograms obtained from exponential mouse lymphoma cells (L5178Y). The numbers of labeled S phase cells, autoradiorgraphically determined from cells sorted at 2-channel intervals in the G 1 /early S and late S/G 2 M regions of the histogram, were compared with the numbers of computed S phase cells in comparable 2-channel intervals as predicted by several computer algorithms used to extract cell cycle phase distributions from DNA histograms. Polynomial and multirectangle algorithms gave computed estimates of total %S in close agreement with the tritiated thymidine labeling index for the cell population, while multi-Gaussian algorithms underestimated %S. Interval autoradiographic and algorithm studies confirmed these results in that no significant differences were found between the autoradiographic S phase distribution and S phase distributions calculated by the polynomial and multirectangle models. However, S phase cells were significantly underestimated in G 1 /early S by a constrained multi-Gaussian model and in both G 1 /early S and late S/G 2 by an unconstrained multi-Gaussian model. For the particular cell line (L5178Y), staining protocol (mithramycin following ethanol fixation) and instrumentation (Coulter TPS-2 cell sorter) used in this study, close agreement between computed %S and tritiated thymidine labeling index was found to be a reliable indicator of an algorithm's success in resolving S phase cells in the G 1 /S and S/G 2 transition regions of the DNA histograms.
A jackknife-like procedure is developed for producing standard errors of estimate in maximum likelihood factor analysis. Unlike earlier methods based on information theory, the procedure developed is computationally f...
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A jackknife-like procedure is developed for producing standard errors of estimate in maximum likelihood factor analysis. Unlike earlier methods based on information theory, the procedure developed is computationally feasible on larger problems. Unlike earlier methods based on the jackknife, the present procedure is not plagued by the factor alignment problem, the Heywood case problem, or the necessity to jackknife by groups. Standard errors may be produced for rotated and unrotated loading estimates using either orthogonal or oblique rotation as well as for estimates of unique factor variances and common factor correlations. The total cost for larger problems is a small multiple of the square of the number of variables times the number of observations used in the analysis. Examples are given to demonstrate the feasibility of the method.
The production of a certain amount of a single product in the minimum time using n heterogeneous facilities is considered. The production quantities for particular facilities must lie within certain bounds at certain ...
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The production of a certain amount of a single product in the minimum time using n heterogeneous facilities is considered. The production quantities for particular facilities must lie within certain bounds at certain times. Thus, in general, the production at every facility is performed in periods, tho numbers of which are a priori unknown. During these periods the numbers have to be found together with the production quantities. An effective algorithm is presented for solving the above problem optimally for time/production quantity, convex or concave functions. In the algorithm, some special properties of optimal solutions are used, and because of this it may be useful in practice. [ABSTRACT FROM AUTHOR]
A simple computer algorithm along with its Fortran programme is presented for extracting all trees or directed trees of a linear graph directly from the incidence matrix. The method is based on the successive upper tr...
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A simple computer algorithm along with its Fortran programme is presented for extracting all trees or directed trees of a linear graph directly from the incidence matrix. The method is based on the successive upper triangularization of the reduced incidence matrix to search out non-singular majors and therefore identifying all (directed) trees. Properties of the incidence matrix are effectively incorporated to reduce computation time and storage requirements and to avoid duplications. [ABSTRACT FROM AUTHOR]
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