Influence of eccentricity on the frequency limitations of circular-pad via-holes

We study the influence of the technologically caused eccentricity of a circular-pad via-hole. We derive an eigenvalue equation using a rigorous method based on a linear transformation of the via-hole polar coordinates. The eigenvalue equation is used to compute the modal resonant frequencies and the modal fields of the eccentric via. It is shown that the via-hole misalignment shifts the modal frequencies and influences its frequency band. The proposed model is verified with published experimental data, and is also compared with results generated with the full-wave simulator Agilent Momentum-2002.     

Adaptive perceptual color-texture image segmentation.

We propose a new approach for image segmentation that is based on low-level features for color and texture. It is aimed at segmentation of natural scenes, in which the color and texture of each segment does not typically exhibit uniform statistical characteristics. The proposed approach combines knowledge of human perception with an understanding of signal characteristics in order to segment natural scenes into perceptually/semantically uniform regions. The proposed approach is based on two types of spatially adaptive low-level features. The first describes the local color composition in terms of spatially adaptive dominant colors, and the second describes the spatial characteristics of the grayscale component of the texture. Together, they provide a simple and effective characterization of texture that the proposed algorithm uses to obtain robust and, at the same time, accurate and precise segmentations. The resulting segmentations convey semantic information that can be used for content-based retrieval. The performance of the proposed algorithms is demonstrated in the domain of photographic images, including low-resolution, degraded, and compressed images.     

Properties determining choice of mother wavelet

Properties of wavelets with finite as well as infinite support are summarised to facilitate mother wavelet selection in a chosen application. The quantitative guidelines reduce dependence on trial-and-error schemes resorted to for selection and underscore the importance of such selection in any application of interest. In wavelet-based image sequence superresolution, studied during the last four years, the use of a B-spline mother wavelet is justified.     

The aligned Si nanowires growth using MW plasma enhanced CVD

New and simple modification of vapor-liquid-solid process for Si nanowires growth based on microwave plasma enhanced chemical vapor deposition that uses solid-state Si target as a source of Si atoms was developed. The method was temperature and pressure controlled evaporation of solid phase of Si source in hydrogen microwave plasma. Aligned growth of Si nanowires was performed in local electric field by applying of constant negative bias to substrate holder. Deposited Si nanowires were studied by scanning electron microscopy (SEM), Raman and photoluminescence spectroscopy. Correlation between photoluminescence spectra and Si nanowires properties were studied.     

Conduction band states of transition metal (TM) high-k gate dielectrics as determined from X-ray absorption spectra

This paper uses X-ray absorption spectroscopy to study the electronic structure of the high-k gate dielectrics including TM and RE oxides. The results are applicable to TM and rare earth (RE) silicate and aluminate alloys, as well as complex oxides comprised of mixed TM/TM and TM/RE oxides. These studies identify the nature of the lowest conduction band d^* states, which define the optical band gap, E_g, and the conduction band offset energy with respect to crystalline Si, E_B. E_g and E_B scale with the atomic properties of the TM and RE atoms providing important insights for identification high-k dielectrics that meet performance targets for advanced CMOS devices.     

Three hardware architectures for the binary modular exponentiation: sequential, parallel, and systolic

Modular exponentiation is the cornerstone computation in public-key cryptography systems such as RSA cryptosystems. The operation is time consuming for large operands. This paper describes the characteristics of three architectures designed to implement modular exponentiation using the fast binary method: the first field-programmable gate array (FPGA) prototype has a sequential architecture, the second has a parallel architecture, and the third has a systolic array-based architecture. The paper compares the three prototypes as well as Blum and Paar's implementation using the time /spl times/ area classic factor. All three prototypes implement the modular multiplication using the popular Montgomery algorithm.     

Tunneling recombination in spatially inhomogeneous structures

Methods for finding the parameters (energies and capture coefficients for electrons and holes) of the levels involved in the formation of the recombination flux are suggested. The temperature variation of these parameters for AlGaN/InGaN/GaN and InGaN/SiC structures is discussed. The parameters of the levels responsible for tunneling recombination are determined.     

Magnetic Fluids and Their Use in Transducers

Magnetic fluids are now widely used to implement transducer architectures. These fluids have valuable properties compared to traditional materials. In this column, a brief overview of magnetic fluids and their traditional uses in the field of transducers are given and some applications developed at the DIEES laboratory at the University of Catania, Italy are presented