A modified Z-source breaker topology is introduced to minimize the reflected fault current drawn from a source while retaining a common return ground path. Conventional Zsource breaker topologies do not provide steady-state overload protection and can only guard against extremely large transient faults. The Z-source breaker can be designed for considerations affecting both rate of fault current rise and absolute fault current level, analogous in some respects to a thermal-magnetic breaker. Detailed analysis and design equations are presented to provide a framework for sizing components in the Z-source breaker topology. In addition, the proposed manual tripping mechanism enables protection against both instantaneous current surges and longer-term over-current conditions. The fault operation intervals of the proposed Z-source breaker topologies are both demonstrated in SPICE simulation and validated in experimental characterization.

Resource conservation decisions require detailed consumption information. This paper presents sensors and signal processing techniques that use pipe vibration signatures to non-intrusively identify water consumption at the appliance level. The method requires as little as one easily installed vibration sensor. This method provides a no-fuss retrofit solution for detecting the operation of a building's water consuming appliances. In addition, flow rate is nonintrusively obtained from a conventional water meter via a new, high sensitivity strap-on magnetic sensor. Together, these two sensors track load operating schedule and water consumption in a building, demonstrated here at three different field test sites.

Abstract-Human-occupancy detection and localization are important in a variety of smart-building applications including building security, assisted-living monitors, and energy-efficient HVAC and lighting. Current implementation of such systems are limited by motion-sensor technologies, e.g. passive infrared (PIR) and ultrasonic sensors, which substitute as occupancy detectors but ultimately suffer from an inability to detect stationary objects. Capacitive sensing can detect stationary objects, but the technology has almost exclusively been developed for shortrange human detection and localization, e.g. touch-screen human interfacing of smart-devices. This paper presents a transmitterreceiver platform for research and development of capacitive sensing for long-range human-occupancy detection and localization. During testing, the system revealed a detection range of 3.5 meters, a typical room dimension in homes. Further, tests of a multi-transmitter, single-receiver system in a 3.2 m x 3.2 m space showed the system's potential for occupant-localization. Ultimately, this system represents an alternative to PIR and ultrasonic motion sensors, and has the potential to increase smart-building system implementation.

Better water consumption decisions benefit from detailed use information. Easily installed non-intrusive vibration sensors provide a "no-fuss" retrofit solution for detecting the operation of water consuming appliances. The sensors measure pipe vibration, which are revealed to be a rich source of information for identifying loads. Vibration is processed to extract power spectral density based features which are classified with a clustering algorithm trained during install. The results can be used to track load operating schedule from the vibration data collected from as little as one pipe in a home. Mechanics governing the observed signals, and signal processing to extract operating information, are discussed in this paper. Field data from three different homes demonstrates the accuracy of this approach.