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This paper gives an application of SpaceWire Network on transferring spaceborne data & information. The on-board data is classified as payload data and platform management data. Accordingly, the on-board network is divided into payload data subnet and platform data subnet that are used to deliver payload data and platform management data respectively. Two different high-level protocol stacks are selected for the two subnets to satisfy the different transmission demands of payload data and platform management data.

This paper discusses the stabilization controller design for a class of discrete-time nonlinear networked control systems under consideration of both the networked-induced delay and data packed dropout. Based on the Lypunov-Krasovskii function method and LMI technique, a state feedback controller is designed. The admissible bound of networked-induced delay and the packet loss is also presented in terms of LMI. A numerical example is provided to demonstrate the effectiveness of our approach.

This paper discusses the robust L2-Linfin filter design for delta-operator uncertain time delay systems. Applying the linear matrix inequality (LMI) technique, a sufficient condition of the existence of L2-Linfin filter is proposed and the design method of robust L2-Linfin filter for delta-operator uncertain time delay systems is derived. A numerical example shows the effectiveness of the method proposed.

Characterizing percolation patterns in unsaturated zones has posed a greater challenge to numerical modeling investigations than comparable saturated zone studies, because of the heterogeneous nature of unsaturated media as well as the great number of variables impacting unsaturated zone flow. This paper presents an integrated modeling methodology for quantitatively characterizing percolation patterns in the unsaturated zone of Yucca Mountain, Nevada, a proposed underground repository site for storing high-level radioactive waste. It takes into account the multiple coupled processes of air, water, heat flow and chemical isotopic transport in Yucca Mountain s highly heterogeneous, unsaturated fractured tuffs. The modeling approach integrates a wide variety of moisture, pneumatic, thermal, and isotopic geochemical field data into a comprehensive three-dimensional numerical model for modeling analyses. Modeling results are examined against different types of field-measured data and then used to evaluate different hydrogeological conceptual models and their results of flow patterns in the unsaturated zone. In particular, this integration model provides a much clearer understanding of percolation patterns and flow behavior through the unsaturated zone, both crucial issues in assessing repository performance. The integrated approach for quantifying Yucca Mountain s flow system is also demonstrated to provide a comprehensive modeling tool for characterizing flow and transport processes in complex subsurface systems.

This paper deals with the problem of stabilization of networked stochastic systems subject to actuator saturation. The networked control systems (NCSs) are modeled as stochastic systems with time-varying input delays under considering the networked-induced time delay. A delay-dependent sufficient condition for the mean-square stability of NCSs is derived by using Lyapunov-Krasovskii approach and a descriptor model transformation. An associated solution of the problem can be obtained by solving a set of linear matrix inequalities that is numerically feasible with commercially available software. A simulation example is provided to demonstrate the effectiveness of the proposed method.

Placing a special mount of buffers at the node in networked control systems, the stochastic time delay can be transformed to a deterministic delay. Then the stochastic networked control systems can be transformed to a deterministic delay system. Three equivalent systems of deterministic networked control systems are presented. Three kinds of output feedback controller of deterministic system are designed. The simulation results show the proposed methods are right and effective.

Two biodegradation models are developed to represent natural attenuation of fuel-hydrocarbon contaminants as observed in a comprehensive natural-gradient tracer test in a heterogeneous aquifer on the Columbus Air Force Base in Mississippi, USA. The first, a first-order mass loss model, describes the irreversible losses of BTEX and its individual components, i.e., benzene (B), toluene (T), ethyl benzene (E), and xylene (X). The second, a reactive pathway model, describes sequential degradation pathways for BTEX utilizing multiple electron acceptors, including oxygen, nitrate, iron and sulfate, and via methanogenesis. The heterogeneous aquifer is represented by multiple hydraulic conductivity (K) zones delineated on the basis of numerous flowmeter K measurements. A direct propagation artificial neural network (DPN) is used as an inverse modeling tool to estimate the biodegradation rate constants associated with each of the K zones. In both the mass loss model and the reactive pathway model, the biodegradation rate constants show an increasing trend with the hydraulic conductivity. The finding of correlation between biodegradation kinetics and hydraulic conductivity distributions is of general interest and relevance to characterization and modeling of natural attenuation of hydrocarbons in other petroleum-product contaminated sites.