Distribution of irreducible polynomials of small degrees over finite fields

D. Wan very recently proved an asymptotic version of a conjecture of Hansen and Mullen concerning the distribution of irreducible polynomials over finite fields. In this note we prove that the conjecture is true in general by using machine calculation to verify the open cases remaining after Wan's work.

     

Some higher-order modifications of Newton’s method for solving nonlinear equations

In this paper we consider constructing some higher-order modifications of Newton’s method for solving nonlinear equations which increase the order of convergence of existing iterative methods by one or two or three units. This construction can be applied to any iteration formula, and per iteration the resulting methods add only one additional function evaluation to increase the order. Some illustrative examples are provided and several numerical results are given to show the performance of the presented methods.     

Magnetic and magnetotransport properties in the n-type (Ga,Mn)N thin films

We present the magnetic and magnetotransport properties of epitaxial (Ga,Mn)N films with nominal Mn concentration (x=0.1–0.73%) grown by plasma-enhanced molecular beam epitaxy (PEMBE). X-ray diffraction (XRD) reveals that (Ga,Mn)N has the single-phase wurtzite structure without secondary phases. The epitaxial (Ga,Mn)N films were found to exhibit n-type conductivity, ferromagnetic ordering with Curie temperature in the range 550–700 K, and in-plane magnetic anisotropy. The negative magnetoresistance (MR) was observed at temperatures below 50 K and was found to gradually increase with decreasing temperature.     

Quantum control and manipulation of multi-color light fields

Quantum control of stationary multi-color (MC) light fields in resonant medium with multi-Λ scheme of atomic transition is proposed. We have found the general analytical solution in the adiabatic limit of quantum evolution resulting from the interaction of the slow probe light with the new fields generated in the nondegenerate multi-wave mixing scheme. We have found a critical condition for the stopping and quantum manipulation of the MC-light fields where the united light group velocity can be reduced down to zero with optimal spectral parameters while preserving the delicate quantum correlations of the initial probe light pulse. The manipulations, which provide the effective transference of quantum probe light to the new multifrequency light fields have been analyzed. The text was submitted by the authors in English.     

Collisionless self-focusing of CO210 µm P(20) laser light in SF6

We develop a simple intuitive picture of the vibration-rotation structure of the SF6molecule such that the molecular susceptibility responsible for self-focusing can be calculated. We treat the propagation dynamics by generalizing the standard steady-state Gaussian propagation equations to include the important effect of absorption in the wings of the spatial profile. By calibrating the model to absorption data at CO210 μmP(2)we find good agreement with beam waist data at the same wavelength. Absorption in the wings is dominant at low laser fluences, and the real part of the susceptibility is responsible for the defocusing-to-focusing turnover in the beam waist near 100 mJ/cm², consistent with the interpretation of Nowak and Ham [6].     

Use of test structures and results of electrical tests for silicon-on-sapphire integrated circuit processes

To obtain parametric data characterizing an IC processing schedule, a pattern of specialized test devices was used in conjunction with a powerful computer-controlled testing and data-reduction system. A test programming system which allows looping and branching was used to control instrumentation having capacitance measurement capability in addition to the usual voltage and current instrumentation. The test devices (MOS capacitor, transistor, and various other types) were tested automatically using the system. Computer-based data logging, analysis, and display generation techniques were necessary so the large bulk of data taken could be-reduced to physically meaningful parameters whose significance can be readily comprehended. In addition to the usual statistical analysis methods, a perspective three-dimensional plot showing parameter values as a function of position in the wafer plane was found most valuable. This data generation system is felt to be a necessary step to providing a complete characterization of both the capabilities and limitations of an IC fabrication scheme, which is vital to both the circuit designer and the line process engineer.     

Einflu? der Triaden-Konzentration auf die Glastemperatur von Copolymeren. 2. Mitt.

Ohne Zusammenfassung     

Generalization of simulation results practicality of statistical methods

The major purpose of this paper is to evaluate the practical use of statistical techniques in both the generalization or analysis of simulation results, and the design of simulation experiments. This problem is investigated with the help of a real-life system, namely the container terminus of ECT in Rotterdam. This system is modeled by a simulation program. The relationship between the simulation response and its input variables is modeled by a linear regression model: metamodel or auxiliary model. The paper summarizes regression analysis including generalized least squares which might be used for simulation responses with non-constant variances. The validity of the postulated regression metamodel is tested statistically: F- and t-statistics. The selection of the situations to be simulated, is done through experimental design methodology, permitting both quantitative and qualitative factors. The statistical techniques apply not only to simulation but also to real-life experiments.     

Modeling the dispersion of radionuclides released during reactor accidents aboard nuclear-powered vessels

Provenance determinations of pottery by chemical analysis is reviewed and shown to work well. Since pottery is produced from a well homogenized clay paste according to a certain recipe, sharp elemental patterns are expected for a series of products having the same origin. To obtain such patterns when forming compositional groups of pottery, a consideration of experimental errors, a correction for dilution and a choice of only stable elements is necessary. The patterns thus obtained will have low probability of overlap with groups of different origin. Examples for well defined groups of German stonewares and of Mycenaean wares from the Peloponnese are recorded.