Scattering of EM waves from a slightly rough surface of a generallyanisotropic plane-layered halfspace

The problem of plane wave scattering by a slightly rough boundary of an arbitrarily layered medium with general anisotropy of electric and magnetic properties is considered using boundary conditions transference method and a small perturbation approximation combined with the Green's functions technique. It is shown that in the Born approximation, the second statistical moments of the fluctuation field scattered from an inhomogeneous anisotropic halfspace can be expressed exclusively in terms of the external parameters referring to a flat boundary and the spectral density of roughness. In the present circumstance, the set of the external parameters includes the four plane-wave reflection coefficients from a flat boundary and the (limiting) values of constitutive parameters of the adjacent media at said boundary, Within the framework of the outlined approach, the covariance dyads, Poynting's vector, scattering coefficients and Stokes parameters of the fluctuation field, and the Mueller matrix for a rough boundary are calculated     

Thermal/structural dynamic analysis via approximate analytical approach

The present paper uses a classical Galerkin weighted residual formulation to obtain the approximate analytical solution of a thermally loaded beam executing free flexural vibrations. The approach used is one where the time variable is considered in the same manner as the spatial variable, and is included in the basis functions. The basis functions used in the approach are polynomials obtained from the terms of a power series, with the condition of nullity on the boundary. This choice simplifies the algebraic manipulations considerably and yields close form expressions for components of the system matrix. The latter also simplifies the numerical computation of coefficients of the approximating polynomial. The approach provides benefits in terms of increased accuracy and lower computational costs.     

The complex role of perceptual organization in visual display design theory.

Two experiments were performed to test and extend the current 'emergent features' approach to display design for dynamic failure detection tasks. It was predicted that a display whose emergent features were well-mapped to goal-relevant task invariants would lead to better failure detection performance than either of two alternative displays. Contrary to prediction. Experiment 1 showed no differences in failure detection speed or accuracy across displays. The reason for this may have been that subjects did not discover the mapping between the mathematical properties of the task and the emergent feature, so in Experiment 2 subjects were explicitly instructed about the mapping and were advised on how to use the display geometry to help their performance. A significant difference in failure detection speed emerged, but the display supporting fastest performance was not the one with the well-mapped emergent feature. These results suggest that alternative perceptual organizational factors were at work which overpowered the intended effect. The results also underscore the difficulty of developing a theory of display design, and their impact on current theories is outlined.     

HSLA-80/100钢的焊接

对ＨＳＬＡ－８０／１００钢的焊接性、焊接材料及焊接工艺进行了综述，并指出了现存在的主要问题。     

The optimisation of higher order resampling methods in a multiprocessor environment

The processing of images obtained from satellites often involves highly repetitive calculations on very large amounts of data. This processing is extremely time consuming when these calculations are performed on sequential machines. Parallel computers are well suited to handling computationally expensive operations such as higher order interpolations on large data sets. This paper decribes work undertaken to develop parallel implementations of a set of resampling procedures on an Alliant VFX/4. Each resampling procedure implemented has been optimised in three stages. First, the algorithm has been restructured, where two-dimensional resampling is performed by two one-dimensional resampling operations. Second, each procedure has been reprogrammed in such a way that the autoparallelisation provided by the FX/Fortran compiler has been exploited. Thirdly, data dependent analysis of each procedure has been performed in order to achieve full optimization of each procedure; each procedure has been restructured where appropriate to circumvent vectorisation and concurrency inhibiting data dependencies. The nature and extent of the code optimization achieved for each procedure is presented in this paper. The original code for the most computationally expensive procedure, as targeted at a sequential machine, was found to have an execution time of 4900 seconds on the Alliant VFX/4 when compiled with regular compiler optimization options. Following algorithmic redesigning and reprogramming of the code, as indicated in stage 1 and stage 2, the execution time was reduced to 248 seconds. Restructuring of the code following data dependency analysis indicated in stage 3 in order to avoid data dependencies and allow concurrency and vectorisation, further reduced execution time to 162 seconds. The consequence of this work is that higher-order resampling methods which had not previous been practical are now routinely performed on the Alliant VFX/4 at the University of Dundee.     

Mechanism of current transfer in oxidized iron ore minerals

Mining Institute, Krivoi Rog. Translated from Fiziko-Technicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 107-116, March-April, 1992.     

Method of calculating pneumatic impactors with one controlled chamber

Institute of Mining, Russian Academy of Sciences, Novosibirsk. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 3, pp. 58–67, May–June, 1992.     

Synthetic resins: XV. Chelation ion exchange properties of 2,4- dinitrophenylhydrazone of resacetophenone-formaldehyde resin

A number of copolymers were synthesised by condensing the 2,4-dinitrophenylhydrazone of resacetophenone with substituted benzoic acids/ phenols and formaldehyde in the presence of sodium hydroxide or hydrochloric acid. The decomposition temperature, solubility and viscosity of the polymers have been determined. The ion-exchange properties have been studied by using a batch equilibrium method. The distribution of a number of metal ions between an aqueous solution and the resin have been measured. A wide range of pH and variable ionic strengths have been investigated.