Abstract
In the scope of the reregulation process of the electric sector, both competitive pool markets and contract mechanisms at the generation and commercialization levels have been emerging. At the wholesale level, and apart from Pool structures and Bilateral Contracts, there are hybrid models in which these two types of structures coexist. In any case, the dispatch coming from the Pool Market Operator, prepared according to the buying and selling offers, together with the bilateral contracted powers must be analyzed from a technical point of view by an independent entity - System Operator. The System Operator aims at checking if the scheduled injected powers do not lead to a decrease of the security standards of the system. Taking in account this concern, in this paper we describe several models to perform the technical validation of sets of electricity schedules, namely trying to minimize the financial impact of the required changes on pre-scheduled generations and loads. This objective is modelled in terms of maximizing the satisfaction degree felt by the participants in the market. The developed application uses Simulated Annealing to solve the corresponding optimization problems. In Section IV of this paper we will include results obtained from several simulations in order to illustrate and demonstrate the interest of the referred models. © 2001 IEEE.

Abstract
In this paper we present a Monte Carlo based application to evaluate estimates of nodal marginal prices leading to target prices of transmission congestion contracts. The application integrates an optimization model to evaluate nodal marginal prices for each sampled state including an estimate of transmission losses. This formulation is integrated in a Monte Carlo simulation in order to deal with the probabilistic nature of component outages and to allow the user to represent load behavior using Load Duration Curves. The computational performance of the Monte Carlo simulation is enhanced by adopting a variance reduction acceleration technique based on a regression function. At a final section the paper includes results from a case study to illustrate the application of the model and to evaluate the efficiency of the referred acceleration technique. © 2001 IEEE.

Abstract
This paper presents a review of the state of the art on Intelligent Transportation Systems. ITS involves a large number of research areas and, therefore, this paper focus on those we believe to be the most relevant. The main purpose is to study the achievements attained in the last years and to give an overview of possible directions towards future research. © 2001 EUCA.

Abstract
This paper presents a review of the state of the art on Intelligent Transportation Systems. ITS involves a large number of research areas and, therefore, this paper focus on those we believe to be the most relevant. The main purpose is to study the achievements attained in the last years and to give an overview of possible directions towards future research.

Abstract

Abstract
In this paper a combined Monte Carlo-Hybrid Transient Stability approach for the dynamic security analysis of a multimachine power system is proposed. This approach evaluates a probabilistic measure of the transient stability, instead of just a particular response to a specified disturbance. Due to the large number of simulations required, the application of a hybrid method to assess transient stability reduces drastically the computing time. A probabilistic version of the software package TRANsySTEM, developed by the authors to study the transient security of a multimachine system, was applied to a test power network. During the simulation time, the occurrence of disturbances and the subsequent protective actions are assumed as a stochastic process. Finally, the obtained results are discussed and some conclusions that provide a valuable contribution to the understanding of the system dynamics are pointed out. © 2001 IEEE.