Spectral efficiency (SE) of massive multiple-input multiple output (MIMO) systems with a very large number of antennas at the base station (BS) considering for space constraint antennas are investigated in this paper. In literature, fixed spacing inter-element were considered, the number of antennas increases with a fixed total distance in a practical topology an inversely proportional to inter...

We studied spatial integration at low contrasts by testing the detection thresholds of multi-Gabor element displays, examining configuration parameters such as orientation uniformity, contour smoothness, continuity, spacing and relative phase. We find that detectability depends on stimulus geometry and is constrained by collinearity and proximity spatial relationships. For textures, thresholds ...

In this paper, flow past around two circular cylinders which are tandem arranged at a Reynolds number of 200 is numerically investigated by spectral element method. To validate the numerical method for incompressible Navier–Stokes equations, the benchmark problem of flow over a single circular cylinder is employed, with the numerical results in a good agreement with the available literatures. T...

Creating a plane wave across an antenna under test is important for accurate antenna measurements. This paper optimizes the location and weightings of an array of line sources in order to approximate a plane wave at a given location in space. The amplitude and phase ripples across a desired test aperture are optimized to be much less than that of a uniform array with the same number of elements...

The level density in a many-particle Fermi system at a given excitation energy is exponentially large with respect to the number of active particles n, and the corresponding mean level spacing D is very small. We consider the eigenstates of the system in the basis of multi-particle excited states constructed of some non-interacting single-particle orbitals. Most of the basis states are not coup...

To investigate the mechanical behavior of profiled steel-concrete composite deck with modified clothoid (MCL) connectors under fatigue load, a method for calculating residual carrying capacity is proposed, and finite element (FE) model established to analyze mechanism decks after failure. The maximum error between theoretical test result 4%, model, 9%. indicates that capacities obtained from ac...

Stereological methods for serial sections traditionally assume that the sections are exactly equally spaced. In reality, the spacing and thickness of sections can be quite irregular. This may affect the validity and accuracy of stereological techniques, especially the Cavalieri estimator of volume. We present a new formula for the accuracy of the Cavalieri estimator that includes the effect of ...

The relationship between species richness and the occupation of niche space can provide insight into the processes that shape patterns of biodiversity. For example, if species interactions constrained coexistence, one might expect tendencies toward even spacing within niche space and positive relationships between diversity and total niche volume. I use morphological diversity of passerine bird...