To study the steady state behavior of small integrated AC/DC power systems, a new realization of AC equivalent approach to AC/DC power flow is proposed in this paper. Depending on control modes, the converter AC terminal buses are modeled as constant voltage bus (slack bus) and nonlinear load bus (PI bus). As a result the whole system and corresponding Jacobian matrix become area-decoupled. In this paper we study two control modes through analysis of multiple load flow solutions thus providing a quantitative and qualitative assessment of feasible and controllable system operating points.

This paper provides an of overview of local bifurcation theory and its application to power system voltage stability analysis. The qualitative behavior of power system dynamics as modeled by differential-algebraic equations is discussed, followed by a summary of the concepts and tools for the analysis of local bifurcation from equilibria. Computational methods for locating and classifying bifurcation points as they have been applied in power system analysis are reviewed. Several examples are given.

The suboptimum design of optimum receivers in nonlinear no-memory modulation systems in the presence of white Gaussian measurement noises is considered. Approximate initial-value solutions to a nonlinear Fredholm integral equation of the Hammerstein type with a symmetric semidegenerate (or separable) covariance kernel are given with the aid of an invariant embedding and the first-order Taylor series expansion. They are new online approximate filters and fixed-point smoothers using the covariance information of the signals and noises in the optimum receiver. A simple numerical example for a phase modulation system is shown.

A simulation model of water pollution dynamics for computer-aided analysis of water quality along an estuary is developed. The model is based on the analytical solution of the diffusion equation describing the pollution concentration when the vertical and lateral dynamics of the estuary are negligible. The estuary is simulated by a cascade connection of uniform distributed parameter networks which represent estuary segments. Each distributed parameter network is treated as a two-port device whose input-output characteristics in the frequency domain are given by its transmission matrix. An algorithm is given for approximating the two-port parameters to any prescribed accuracy so that the two-port dynamics can be synthesized as an active lumped-parameter electrical network. This network, when used with a computer-aided circuit analysis program, yields the pollution concentration profile along the estuary.

This study considers the message propagation problem in a "net-alert" situation through directed and undirected random networks havingnnodes and probability of connection between the distinct pairs of nodes equal top. The solution has been obtained by analyzing the structure of the random networks in terms of the probability distribution of the number of contacted new nodes, which are separated from the originator(s) of the message by simple chain progressions ofklinks. From these probability distributions, the average message propagation, the weak connectivity, and thekth terminal reliability are obtained. To aid the computation of these quantities first-order difference equations that approximate the average message propagation, the weak connectivity, and thekth terminal reliability are given. The application of the results is shown for random networks having several values ofnandp.