Broadband Dual-Polarized Multidipole Antenna for Base Station Applications

A wideband dual-polarized multidipole antenna for base station applications is proposed. It consists of a pair of large square-shaped loop dipoles and a pair of small rectangle loop dipoles as radiation elements. A pair of small rectangle loop dipoles is fed by T-shaped feed structure which is in the large square-shaped loop dipoles radiating arm so that the antenna generates an additional resonance and obtains a wider bandwidth. The proposed antenna was fabricated and measured, and the results show that the antenna achieves a wide impedance bandwidth of 63.7 % with VSWR<1.5 covering the frequency range from 1.55 to 3 GHz. A high isolation is better than 29 dB within the operating frequency bandwidth. Moreover, an average gain 8 dBi and a stable radiation pattern with 3 dB beamwidth of 69° ± 4° at H-plane are obtained.

New water mites of Torrenticolidae (Acari, Hydrachnidia) from Jiangxi Province, P. R. China

Three torrenticolid species new to science, i.e. Monatractides trilaminatus sp. nov., Torrenticola lushanensis sp. nov., and T. planusirostrum sp. nov. are described from Jiangxi Province, P. R. China. M. trilaminatus sp. nov. can be distinguished by the shoulder and frontal platelets fused together and formed into a pair of platelets; infracapitular bay U-shaped, extremely deep and narrow; the tip of coxae I with a small rectangle extension. T. lushanensis sp. nov. can be distinguished by epimeroglandularia 4 at the same level as the 4th pair of acetabula; anal pore on the same line with ventroglandularia 2, and posterior to ventroglandularia 1. T. planusirostrum sp. nov. can be distinguished by infracapitular dorsal apodeme almost absent, ventral apodeme blunt and long, rostrum flat and parallel to the ventral apodeme. Detailed descriptions and illustrations of these species are given in this paper.

Influences of Target Surface Roughness on Impingement Jet Array Heat Transfer: Part 1 — Effects of Roughness Pattern, Roughness Height, and Reynolds Number

The present investigation considers the effects of special roughness patterns on impingement target surfaces to improve the effectiveness and surface heat transfer augmentation levels of impingement jet array cooling. This investigation utilizes various sizes, distributions, shapes, and patterns of surface roughness elements for impingement cooling augmentation. The surface roughness shape considered here is rectangle, in combination with larger rectangular pins. Combinations of small rectangle roughness and large pins are considered together, along with arrays of small rectangular roughness alone. Tests are performed at impingement jet Reynolds numbers of 900, 1500, 5000, and 11000. Local and overall impingement cooling performance depends upon the pattern, distribution, arrangement, and height of the roughness elements, as well as upon the jet Reynolds number. Depending upon the magnitude of jet Reynolds number, different behavior and trends are observed for the small rectangle roughness and large pins together, compared with arrays of small rectangular roughness alone. Overall, results demonstrate the remarkable ability of target surface roughness to produce increased surface heat transfer augmentation levels of impingement jet array cooling, relative to target surfaces which are smooth.

Skeleton-based 3D Surface Parameterization Applied on Texture Mapping

Assume a 2D manifold surface topologically equivalent to a sphere with handles we propose a novel 3D surface parametrization along the surface skeleton. First, we use a global mapping of the surface vertices onto a computed skeleton. Second, we use local mapping of the surrounding area of each skeleton segment into a small rectangle whose size is derived based on the surface properties around the segment. Each rectangle can be textured by assigning the local u;v texture coordinates. Furthermore, these rectangles are packed into a large squared texture called skeleton texture map (STM) by approximately solving a palette loading problem. Our technique enables the mapping of a texture onto the surface without necessity to store texture coordinates together with the model data. In other words it is enough to store the geometry data with STM and the coordinates are calculated on the fly.

Configuration Saliency Revealed by Dichoptic Masking

We studied suprathreshold spatial integration by testing the saliency of multi Gabor element configurations in dichoptic masking conditions. Dichoptic presentations allows for a competition between spatially overlapping suprathreshold stimuli that involve nonoverlapping receptive fields in the first stage of visual filtering. Different spatial configurations of Gabor patches (sigma=lambda=0.12 deg) were presented to one eye (target) together with a bandpass noise presented to the other eye (mask). After a short rivalry period (128 ms) in which a dominance of one eye was established, a probe (a randomly positioned small rectangle of reduced contrast in the target) was presented for an additional detection period (80 ms). Probe detection performance was measured (2AFC) by finding the mask contrast leading to 75% correct response. We find that textures of randomly oriented patches are more dominant than uniform textures where the effect decreases and even reverses with decreasing of contrast. For suprathreshold (1-D) contours, however, we find that smooth collinear contours are more dominant than ‘jagged’ ones, regardless of contrast. These findings suggest principles underlying an early lateral integration mechanism based on contrast-dependent inhibitory and excitatory connections. This mechanism could be based on iso-orientation surround (2-D) inhibition and collinear (1-D) facilitation, with inhibition being more effective at high contrasts.