In this paper we present a novel sequence-based RF localization algorithm called Ecolocation. Our algorithm determines the location of unknown nodes by examining the ordered sequence of received signal strength (RSS) measurements taken at multiple reference nodes. We employ a constraint-based approach that provides for robust location decoding even in the presence of random RSS fluctuations due to multipath fading and shadowing. Through extensive systematic simulations, and a representative set of real mote experiments, we show that over a wide range of settings Ecolocation performs better than other state of the art approaches in terms of localization accuracy and precision.

Bosch has developed and demonstrated a novel direct current (DC) microgrid system that maximizes the efficiency of locally generated photovoltaic energy while offering high reliability, safety, redundancy, and reduced cost compared to equivalent alternating current (AC) systems. Several demonstration projects validating the system feasibility and expected efficiency gains have been completed and additional ones are in progress. This paper gives an overview of the Bosch DC microgrid system and presents key results from a large simulation study done to estimate the energy savings of the Bosch DC microgrid over conventional AC systems. The study examined the system performance in locations across the United States for several commercial building types and operating profiles. It found that the Bosch DC microgrid uses generated PV energy 6%-8% more efficiently than traditional AC systems.

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Pervasive systems are rapidly growing in size, complexity, distribution, and heterogeneity. As a result, the traditional practice of developing one-off embedded applications that are often rigid and unmanageable is no longer acceptable. This is particularly evident in a growing class of mobile and dynamic pervasive systems that are highly unpredictable, and thus require flexible and adaptable software support. At the same time, many of these applications are mission critical and have stringent fault tolerance requirements. In this paper, we argue that an effective approach to developing software systems in this domain is to employ the principles of software architecture. We discuss the design and implementation of facilities we have provided in a tool-suite targeted for architecture-based development of fault tolerant pervasive systems. Abstract Dispatcher Round Robin DispatcherAbstract Scheduler Fifo Scheduler Abstract Scaffold Brick Architecture Component Connector Event Port IComponent IPort ISerializable IArchitecture #mutualPort ExtensibleComponent AbstractServic eDiscovery ExtensibleConnector AbstractHandler AbstractDeployment ExtensiblePort Abstract Distribution

Software architecture has been widely advocated as an effective abstraction for modeling, implementing, and evolving complex software systems such as those in distributed, decentralized, heterogeneous, mobile, and pervasive environments. Typically, however, architectural abstractions have not been supported directly at the level of system implementation. Instead, even developers with access to state-of-the-art middleware facilities have had to rely on constructs that are at least in part different from those used in the design of their systems. In this paper we argue that it is possible to provide native and flexible software architectural facilities in a middleware platform geared to pervasive environments.We refer to such a platform as "architectural middleware". In support of our argument, we outline the design, implementation, and our experience with a specific architectural middleware platform, which has been used in solving pervasive computing problems in the classroom as well as two industrial domains. We also demonstrate that middleware-level architectural support can be effective, efficient, scalable, and adaptable.