Table of Contents

Abstract: The Jet Propulsion Laboratory has recently developed and built an electronic nose(ENose) using a polymer-carbon composite sensing array. This ENose is designed to be usedfor air quality monitoring in an enclosed space, and is designed to detect, identify andquantify common contaminants at concentrations in the parts-per-million range. Itscapabilities were demonstrated in an experiment aboard the National Aeronautics and SpaceAdministration’s Space Shuttle Flight STS-95. This paper describes a modified nonlinearleast-squares based algorithm developed to analyze data taken by the ENose, and itsperformance for the identification and quantification of single gases and binary mixtures oftwelve target analytes in clean air. Results from laboratory-controlled events demonstrate theeffectiveness of the algorithm to identify and quantify a gas event if concentration exceedsthe ENose detection threshold. Results from the flight test demonstrate that the algorithmcorrectly identifies and quantifies all registered events (planned or unplanned, as singles ormixtures) with no false positives and no inconsistencies with the logged events and theindependent analysis of air samples.

Abstract: In this work we report the design, construction, and applications of an electronictongue (abbreviated e-tongue) based on an array of potentiometric sensors employing theSequential Injection Analysis technique (SIA) operated as a Virtual Instrument implementedin LabVIEW6.1^TM. The system can use transient and stationary responses as the measuredinput information for e-tongues. The new concepts applied, lead to different advantages tobe obtained, such as complete automation, easy handling, saving time, reliability andmodularity.

Abstract: In the paper a discussion on how to optimize LonWorks/EIA-709 sensornetworking technology for wireless applications, in presented. Main solutions offered byLocal Operating Networks (LON, LonWorks) platform attractive for wirelesscommunication, that is, the send-on-delta concept and the sleep mode, are displayed. Thepredictive p-persistent CSMA MAC protocol constituting the heart of the communicationcapability of LON networks is analysed in detail. Next, the message services are described,and the analytical evaluation of delivery reliability is derived. Performance evaluation basedon simulation results for unicast traffic is presented first. In order to highlight the robustnessof the predictive CSMA to overload situations, the saturation performance for a general caseload scenario including multicast transactions is reported. The methods of effectivemanagement of energy consumption in LonWorks networks are discussed. Finally, the LONdesign tradeoffs are summarized.

Abstract: The paper addresses the issue of the send-on-delta data collecting strategy tocapture information from the environment. Send-on-delta concept is the signal-dependenttemporal sampling scheme, where the sampling is triggered if the signal deviates by deltadefined as the significant change of its value. It is an attractive scheme for wireless sensornetworking due to effective energy consumption. The quantitative evaluations of send-on-delta scheme for a general type continuous-time bandlimited signal are presented in thepaper. The bounds on the mean traffic of reports for a given signal, and assumed samplingresolution, are evaluated. Furthermore, the send-on-delta effectiveness, defined as thereduction of the mean rate of reports in comparison to the periodic sampling for a givenresolution, is derived. It is shown that the lower bound of the send-on-delta effectiveness(i.e. the guaranteed reduction) is independent of the sampling resolution, and constitutes thebuilt-in feature of the input signal. The calculation of the effectiveness for standard signals,that model the state evolution of dynamic environment in time, is exemplified. Finally, theexample of send-on-delta programming is shown.