Inferring Personal Information from Demand-Response Systems

Current and upcoming demand-response systems provide increasingly detailed power-consumption data to utilities and a growing array of players angling to assist consumers in understanding and managing their energy use. The granularity of this data, as well as new players' entry into the energy market, creates new privacy concerns. The detailed per-household consumption data that advanced metering systems generate reveals information about in-home activities that such players can mine and combine with other readily available information to discover more about occupants' activities. The authors explore the technological aspects of this claim, focusing on the ways in which personally identifying information can be collected and repurposed. Their results show that, even with relatively unsophisticated hardware and data-extraction algorithms, some information about occupant behavior can be estimated with a high degree of accuracy. The authors propose a disclosure metric to aid in quantifying the impact of data collection on in-home privacy and construct an example metric for their experiment.     

Metaferrites: using electromagnetic bandgap structures to synthesize metamaterial ferrites

A methodology is presented for the design synthesis of metamaterial ferrites, or metaferrites, that retain their desirable magnetic properties at frequencies above 1 GHz. The design synthesis is accomplished by optimizing a high impedance frequency selective surface (HZ-FSS) structure via a genetic algorithm (GA) for the desired effective permeability of an equivalent magnetic substrate backed by a perfect electric conductor ground plane. The ability to optimize the design parameters of these HZ-FSS structures allows for the possibility of synthesizing low-loss dispersive metaferrites with either a positive or a negative real part of the effective permeability at the desired operating frequency band. The results presented in this paper demonstrate five possible metaferrite designs: two with the associated real and imaginary permeabilities for use as low-loss magnetic materials, and three designs for use as absorbing materials.