Location-dependent metamaterials in terahertz range for reconfiguration purposes

We propose and demonstrate a multifunctional location-dependent metamaterial in the terahertz(THz) range in which the unit cell consists of two pairs of coupled resonators. Experimental and simulation results of our devices reveal that both pairs of the coupled resonators will keep their individual resonance modes when they join together. Thus, the overall transmission spectrum is a combination of frequency response spectra of its corresponding constituent parts. While changing the locations of the inner resonators in our structure, controllable width of transmission window and changeable number of transmission dips can be realized. Our design provides a feasible structure for multifunctional microelectromechanical devices.

D-Tree Approach to Constructing Overlapping Location-Dependent Data Regions

For the past few years, there has been an explosion in the number of individuals carrying wireless devices that are capable of conducting location-dependent information services (LDISs) and provide information based on locations specified in the queries. This paper examines the user's demand of vague queries, and then proposes system architecture of LDISs. In particular, based on D-tree index structure, it takes the method of membership function in fuzzy set theory to provide a more user-oriented approach to constructing overlapping location-dependent data regions, called complementary void overlapping data regions. This structure, carrying more information with less additional storage, brings balance between perceived usefulness and responsiveness, energy consumption, and bandwidth contention in wireless communications. The simulations show that this method is more flexible and practical in practice.

Minimum Spanning Trees Across Well-Connected Cities and with Location-Dependent Weights

Consider n nodes{X_(i)}_(1≤i≤n) independently and identically distributed(i.i.d.)across N cities located within the unit square S.Each city is modelled as an r_(n)×r_(n)square,and MSTC_(n)denotes the weighted length of the minimum spanning tree containing all the n nodes,where the edge length between nodes X_(i)and X_(j)is weighted by a factor that depends on the individual locations of X_(i)and X_(j).We use approximation methods to obtain variance estimates for MSTC_(n)and prove that if the cities are well connected in a certain sense,then MSTC_(n)appropriately centred and scaled converges to zero in probability.Using the above proof techniques we also study MST_(n),the length of the minimum weighted spanning tree for nodes distributed throughout the unit square S with location-dependent edge weights.In this case,the variance of MST_(n)grows at most as a power of the logarithm of n and we use a subsequence argument to get almost sure convergence of MST_(n),appropriately centred and scaled.