Abstract
Nonlinear optical properties of conjugated polymers can be measured using various techniques, including third-harmonic generation, two-photon absorption, nonlinear grating coupling and interferometry. These methods will be compared with regard to their suitability for obtaining specific parameters. We illustrate the application of these techniques to the study of pi-conjugated polymeric systems, such as poly(4-BCMU), poly(3-decyl-thiophene) and 4-dialkylamino-4'-nitrostilbene (DANS) side-chain polymer, all of them regarded as candidates for the realization of all-optical switching devices, and outline relevance and limits of each technique.

Abstract
We describe four patients with complex partial seizures and cystic dilatation of one or both occipital horns. The onset of epilepsy was in early infancy in the four cases, with simple and complex partial seizures with secondary generalization; two patients have visual symptomatology at the beginning of seizures. Three patients have an important mental retardation, two of them have visual field defects and one patient has a hemioatrophy. The four patients were studied with CT scan, MRI and several scalp EEG recordings with computerized signal processing methods and simultaneous cognitive studies. None of them had cerebral angiography. These patients are similar to Remillard et al. series of 8 patients with temporal lobe epilepsy and associated visual field defects and enlargement of the occipital horn. The perinatal occlusion of the posterior cerebral artery was the considered etiology which was afterwards questioned by Roger et al. in their series of 500 CT scans of epileptic patients. Our results suggest that epileptogenic areas exceed the lesions seen on neuroradiological imaging. This is of the outmost importance when considering the hypothesis of surgery to control seizures in these patients.

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Abstract
A fuzzy model for power system operation is presented. Uncertainties in loads and generations are modeled as fuzzy numbers. System behavior under known (while uncertain) injections is dealt with by a DC fuzzy power flow model. System optimal (while uncertain) operation is calculated with linear programming procedures in which the problem nature and structure allow some efficient techniques such as Dantzig-Wolfe decomposition and dual simplex to be used. Among the results, one obtains a fuzzy cost value for system operation and possibility distributions for branch power flows and power generations. Some risk analysis is possible, as system robustness and exposure indices can be derived and hedging policies can be investigated.

Abstract
We investigate the third-order nonlinearity of DANS and DAN2 side-chain polymers by tunable third-harmonic generation and nonlinear distributed coupling. The large third-order susceptibility can be interpreted in terms of microscopic cascading of second-order hyperpolarizabilities.

Abstract