Design of a dual-band coplanar waveguide-fed slot antenna with wide frequency separation

This paper presents a novel design for a dual-band coplanar waveguide-fed-slot antenna that operates at 27GHz and 39GHz. Matching this antenna at the two widely separated frequencies is achieved using a special matching network of slot antennas. Experimental and numerical results are presented for the return loss and radiation patterns of this antenna.     

Design and synthesis of microwave coupled resonator diplexers

This paper presents an equivalent circuit model for microwave coupled resonator diplexers. The accuracy of this model is verified numerically. This model is then incorporated into a simple design procedure for coupled resonator diplexers. The accuracy and speed of the procedure is verified for different designs.     

Imidazolinium sulfonate and sulfamate zwitterions as chiral solvating agents for enantiomeric excess calculations

The synthesis of enantiopure unsymmetrical N-heterocyclic based zwitterions incorporating imidazolinium and alkylsulfonate or sulfamate groups is described. The desired compounds were prepared in good yields from 1,3-propanesultone or cyclic sulfamidates and imidazolines. The imidazolinium based zwitterions proved to be versatile chiral solvating agents for Mosher’s acid, alcohols, cyanohydrins, amino alcohols, nitro alcohols, thiols, and carboxylic acids with very high shifts in the ¹H and ¹⁹F NMR.     

Fast Anti-Random (FAR) Test Generation to Improve the Quality of Behavioral Model Verification

Anti-random testing has proved useful in a series of empirical evaluations. The basic premise of anti-random testing is to chose new test vectors that are as far away from existing test inputs as possible. The distance measure is either Hamming distance or Cartesian distance. Unfortunately, this method essentially requires enumeration of the input space and computation of each input vector when used on an arbitrary set of existing test data. This prevents scale-up to large test sets and/or long input vectors.We present and empirically evaluate a technique to generate anti-random vectors that is computationally feasible for large input vectors and long sequences of tests. We also show how this fast anti-random test generation (FAR) can consider retained state (i.e. effects of subsequent inputs on each other). We evaluate effectiveness of applying anti-random vectors for behavioral model verification using branch coverage as the testing criterion.     

Reliability of mesh and torus topologies in the presence of faults

Mesh and torus topologies have been used to implement various multicomputer architectures. Faults in these networks significantly degrade their performance. In this paper, a new Markov model is used to derive a closed form analytical solution for the terminal reliability of the mesh and 2‐dimensional torus. The effect of the added links in the torus on reliability is studied. Networks of various dimensions are analyzed, and all the analytical results are verified by computer simulations. Although the mesh‐connected topology is considered in this paper, the analysis can be readily adopted for any network topology. This revised version was published online in June 2006 with corrections to the Cover Date.     

Some new estimates for the commutators of n-dimensional Hausdorff operator

In this paper, we discuss the boundedness of commutators of high dimensional Hausdorff operator HΦ on Herz type spacesIn addition, central BMO estimates for such commutators are also presented.     

A note on teleparallel Killing vector fields in Bianchi type VIII and IX spaceben times in teleparallel theory of gravitation

In this paper we classify Bianchi type VIII and IX space—times according to their teleparallel Killing vector fields in the teleparallel theory of gravitation by using a direct integration technique. It turns out that the dimensions of the teleparallel Killing vector fields are either 4 or 5. From the above study we have shown that the Killing vector fields for Bianchi type VIII and IX space—times in the context of teleparallel theory are different from that in general relativity.