Improved Spatial Modulation for High Spectral Efficiency

Spatial Modulation (SM) is a technique that can enhance the capacity of MIMO schemes by exploiting the index of transmit antenna to convey information bits. In this paper, we describe this technique, and present a new MIMO transmission scheme that combines SM and spatial multiplexing. In the basic form of SM, only one out of MT available antennas is selected for transmission in any given symbol interval. We propose to use more than one antenna to transmit several symbols simultaneously. This would increase the spectral efficiency. At the receiver, an optimal detector is employed to jointly estimate the transmitted symbols as well as the index of the active transmit antennas. In this paper we evaluate the performance of this scheme in an uncorrelated Rayleigh fading channel. The simulations results show that the proposed scheme outperforms the optimal SM and V-BLAST (Vertical Bell Laboratories Layered space-time at high signal-to-noise ratio (SNR). For example, if we seek a spectral efficiency of 8 bits/s/Hz at bit error rate (BER) of 10^-5, the proposed scheme provides 5dB and 7dB improvements over SM and V-BLAST, respectively.Comment: 7 pages, 4 figures, 1 table, International Journal of Distributed and Parallel Systems (IJDPS) Vol.3, No.2, March 201

2D Face Recognition System Based on Selected Gabor Filters and Linear Discriminant Analysis LDA

We present a new approach for face recognition system. The method is based on 2D face image features using subset of non-correlated and Orthogonal Gabor Filters instead of using the whole Gabor Filter Bank, then compressing the output feature vector using Linear Discriminant Analysis (LDA). The face image has been enhanced using multi stage image processing technique to normalize it and compensate for illumination variation. Experimental results show that the proposed system is effective for both dimension reduction and good recognition performance when compared to the complete Gabor filter bank. The system has been tested using CASIA, ORL and Cropped YaleB 2D face images Databases and achieved average recognition rate of 98.9 %

Report on Tell al-Imsihli: The 2000 and 2001 Seasons

This article summarizes two seasons of excavations at Tell al-Imsihly, a prehistoric site nearly 5 kilometers south of Assur. Archaeological excavations were conducted by Iraq’s State Board of Antiquities and Heritage (SBAH) over a period of two seasons starting in April 2000 and ending in late 2001. Iraqi archaeologists working at Assur were put in charge of investigating the site. Due to damage and incursions on the site from plowing and earthmoving activities, the goals of SBAH’s excavations were to obtain an idea of settlement chronology and activity within and just outside of Tell al-Imsihly. In 2006-2007, Dr. Altaweel collaborated with the Iraqi archaeologists who had excavated the site in order to assist in interpreting some of the archaeological data as well as publication of the excavations to a wide audience. Some original items and records from the excavations are not currently available, and perhaps lost, but the archaeological report compiled by Mr. Hamza and written in Arabic remains. In addition, many of the ceramic drawings and excavation photographs have survived. The data presented by the Arabic report are the basis of the presentation to follow, although some additional details have been provided by Altaweel

INFLUENCE OF WELL LOCATION ON DRAWDOWN IN AREA SURROUNDED BY VERTICAL CUTOFF WALLS

Dewatering systems with vertical partially penetrating cutoff walls are usually used in the case of deep excavation for side support system and further increases the efficiency of the groundwater control system. In this study a parametric analysis was carried out using the finite difference software VISUAL MODFLOW4.2® to study the effect of placing a deep well at different locations inside the excavated area surrounded by impervious wall on drawdown results. The dewatering system under consideration consists of a single partially penetrating deep well having a penetration depth (lw) and well yield (Q). The well is located at variable distances from the corner (the origin of X and Y axes) inside the excavated area surrounded by an impervious wall. The vertical impervious wall has a depth (lc), and the excavated area (A) surrounded with impervious wall is square and having a width (W). The aquifer is unconfined with a depth (H) and is underlain by an impervious layer. The aquifer consists of an extended layer of fine to medium sand having permeability (k). The soil is assumed to be homogenous and isotropic

Activation Energy of Surface Diffusion and Terrace Width Dynamics During the Growth of in (4×3) on Si (100) - (2×1) by Femtosecond Pulsed Laser Deposition

The nucleation and growth of indium on a vicinal Si (100) - (2×1) surface at high temperature by femtosecond pulsed laser deposition was investigated by in situ reflection high energy electron diffraction (RHEED). RHEED intensity relaxation was observed for the first ∼2 ML during the growth of In (4×3) by step flow. From the temperature dependence of the rate of relaxation, an activation energy of 1.4±0.2 eV of surface diffusion was determined. The results indicate that indium small clusters diffused to terrace step edges with a diffusion frequency constant of (1.0±0.1) × 1011 s-1. The RHEED specular beam split peak spacing, which is characteristic of a vicinal surface, was analyzed with the growth temperature to obtain the average terrace width. Gradual reduction in the terrace width during growth of In (4×3) was observed with In coverage and is attributed to the detachment of In atoms from terrace edges. At a substrate temperature of 405 °C, the average terrace width decreased from 61±10 Å, which corresponds to the vicinal Si(100) surface, to an equilibrium value of 45±7 Å after deposition of ∼23 ML. Further In coverage showed a transition of the RHEED pattern from (4×3) to (1×1) and the growth of rounded In islands (average height of ∼1 nm and width of ∼25 nm), as examined by ex situ atomic force microscopy. © 2008 American Institute of Physics. [DOI: 10.1063/1.2909923

Atomic Hydrogen Cleaning of InP(100): Electron Yield and Surface Morphology of Negative Electron Affinity Activated Surfaces

Atomic hydrogen cleaning of the InP(100) surface has been investigated using quantitative reflection high-energy electron diffraction. The quantum efficiency of the surface when activated to negative electron affinity was correlated with surface morphology. The electron diffraction patterns showed that hydrogen cleaning is effective in removing surface contaminants, leaving a clean, ordered, and (2×4)-reconstructed surface. After activation to negative electron affinity, a quantum efficiency of ∼6% was produced in response to photoactivation at 632 nm. Secondary electron emission from the hydrogen-cleaned InP(100)-(2×4) surface was measured and correlated to the quantum efficiency. The morphology of the vicinal InP(100) surface was investigated using electron diffraction. The average terrace width and adatom-vacancy density were measured from the (00) specular beam at the out-of-phase condition. With hydrogen cleaning time, there was some reduction in the average terrace width. The surface quality was improved with hydrogen cleaning, as indicated by the increased (00) spot intensity-to-background ratio at the out-of-phase condition, and improved quantum efficiency after activation to negative electron affinity. © 2002 American Institute of Physics. [DOI: 10.1063/1.1429796

Conductance of S-Alkylisothiouronium Iodides in Methanol at 25° C

Equivalent conductivities are reported for S-Methyl-, S-n- . -Butyl, S-n-Amyl- and S-n-Heptylisothiouronium iodides in methanol (D = 32.63) at 25 °c. The data were analyzed by the Fuoss-Onsager equation for 1 : 1 associated electrolytes. The characteristic constants: the equivalent conductance at infinite dilution A0 , the closest approach distance a0 and the association constant KA are · derived