Pattern Synthesis of Dual-band Shared Aperture Interleaved Linear Antenna Arrays

This paper presents an approach to improve the efficiency of an array aperture by interleaving two different arrays in the same aperture area. Two sub-arrays working at different frequencies are interleaved in the same linear aperture area. The available aperture area is efficiently used. The element positions of antenna array are optimized by using Invasive Weed Optimization (IWO) to reduce the peak side lobe level (PSLL) of the radiation pattern. To overcome the shortness of traditional methods which can only fulfill the design of shared aperture antenna array working at the same frequency, this method can achieve the design of dual-band antenna array with wide working frequency range. Simulation results show that the proposed method is feasible and efficient in the synthesis of dual-band shared aperture antenna array

Pipelined genetic propagation

© 2015 IEEE.Genetic Algorithms (GAs) are a class of numerical and combinatorial optimisers which are especially useful for solving complex non-linear and non-convex problems. However, the required execution time often limits their application to small-scale or latency-insensitive problems, so techniques to increase the computational efficiency of GAs are needed. FPGA-based acceleration has significant potential for speeding up genetic algorithms, but existing FPGA GAs are limited by the generational approaches inherited from software GAs. Many parts of the generational approach do not map well to hardware, such as the large shared population memory and intrinsic loop-carried dependency. To address this problem, this paper proposes a new hardware-oriented approach to GAs, called Pipelined Genetic Propagation (PGP), which is intrinsically distributed and pipelined. PGP represents a GA solver as a graph of loosely coupled genetic operators, which allows the solution to be scaled to the available resources, and also to dynamically change topology at run-time to explore different solution strategies. Experiments show that pipelined genetic propagation is effective in solving seven different applications. Our PGP design is 5 times faster than a recent FPGA-based GA system, and 90 times faster than a CPU-based GA system

On the Cauchy problem for the magnetic Zakharov system

In this paper, we study the Cauchy problem of the magnetic type Zakharov system which describes the pondermotive force and magnetic field generation effects resulting from the non-linear interaction between plasma-wave and particles. By using the energy method to derive a priori bounds and an approximation argument for the construction of solutions, we obtain local existence and uniqueness results for the magnetic Zakharov system in the case of $d=2,3$

Direct determination of the spin structure of Nd2_2Ir2_2O7_7 by means of neutron diffraction

We report on the spin structure of the pyrochlore iridate Nd$_2$Ir$_2$O$_7$ that could be directly determined by means of powder neutron diffraction. Our magnetic structure refinement unravels a so-called all-in/all-out magnetic structure that appears in both, the Nd and the Ir sublattice. The ordered magnetic moments at 1.8 K amount to 0.34(1) $\mu_\mathrm{B}$/Ir$^{4+}$ and 1.27(1) $\mu_\mathrm{B}$/Nd$^{3+}$. The Nd$^{3+}$ moment size at 1.8 K is smaller than that expected for the Nd$^{3+}$ ground state doublet. On the other hand, the size of the ordered moments of the Ir$^{4+}$ ions at 1.8 K agrees very well with the value expected for a $J_\mathrm{eff}$ = 1/2 state based on the presence of strong spin-orbit coupling in this system. Finally, our measurements reveal a parallel alignment of the Nd$^{3+}$ moments with the net moment of its six nearest neighboring Ir$^{4+}$ ions.Comment: http://journals.aps.org/prb/pdf/10.1103/PhysRevB.94.16110

Globalization or Localization? A longitudinal study of successful American and Chinese online store websites

This paper reports the results of a longitudinal study of 2562 images on the homepages of successful American and Chinese online store websites,with the goal of determining whether cultural factors impact their visual presentation and evolution. Descriptive and statistical content analyses reveal that the U.S. and Chinese online store sites showed significant cross-national image differences from their inception; moreover, the Chinese sites diverged further from the U.S. sites over time, strengthening their own cultural identity and suggesting a trend towards localization in a diverse and dynamic world market. These findings support the view that although English-speaking Western culture is widespread in today’s Information Age, other cultures are not necessarily undermined

NIR Calibrations for Soybean Seeds and Soy Food Composition Analysis: Total Carbohydrates, Oil, Proteins and Water Contents

Conventional chemical analysis techniques are expensive, time consuming, and often destructive. The non-invasive Near Infrared (NIR) technology was introduced over the last decades for wide-scale, inexpensive chemical analysis of food and crop seed composition (see Williams and Norris, 1987; Wilcox and Cavins, 1995; Buning and Diller, 2000 for reviews of the NIR technique development stage prior to 1998, when Diode Arrays were introduced to NIR). NIR spectroscopic measurements obey Lambert and Beer’s law, and quantitative measurements can be successfully made with high speed and ease of operation. NIR has been used in a great variety of food applications. General applications of products analyzed come from all sectors of the food industry including meats, grains, and dairy products (Shadow, 1998)