A high-frequency electronic ballast with auto-tracking control was proposed to operate the metal halide lamps at a specific frequency free from acoustic resonance. In case the acoustic resonance should happen, the operating frequency is changed step by step with the auto-tracking control, until the lamp is operated at a frequency with stable operation. The electrical characteristics of the lamps are first investigated. Based on the investigated results, a detection circuit is designed to identify the occurrence of acoustic resonance. With the auto-tracking control, the Class-D half-bridge series-resonant inverter can be adopted for the high-frequency electronic ballast to achieve high efficiency and high power density. The control strategy of auto-tracking is practically realized by a single-chip microprocessor. The proposed approach is implemented on a 70 W test lamp with an operating frequency range from 20 kHz to 30 kHz. To regulate the lamp power at its rated value, a buck-boost converter is used as a pre-regulator, which serves also as a power-factor-corrector to achieve a high power factor at the input line.

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International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Due to Cost and Safety considerations the Range Division of the 412th Test Wing is upgrading remote telemetry (TM) antenna sites to be operated and monitored remotely. This is possible, in part, due to the installation of fiber optic cable, and the use of ATM communications protocol. Both of these applications significantly reduce signal latency from the remote control station located at Ridley Mission Control Center (RMCC) and the Antenna site. This paper discusses the challenges associated with controlling these sophisticated systems remotely. We will also describe the decisions and how they were made, the concerns over system performance, and the impact to other systems. This paper also addresses the technologies chosen to support the requirements and overcome the challenges. The benefits of remote range sensors are also discussed. We will provide top-level block diagrams of the system architecture.

Les Moments ont été largement utilisés dans la reconnaissance de formes et dans le traitement d'image. Dans cette thèse, nous concentrons notre attention sur les 3D moments orthogonaux de Gauss-Hermite, les moments invariants 2D et 3D de Gauss-Hermite, l'algorithme rapide de l'attribut de cohérence et les applications de l'interprétation sismique en utilisant la méthode des moments.Nous étudions les méthodes de suivi automatique d'horizon sismique à partir de moments de Gauss-Hermite en cas de 1D et de 3D. Nous introduisons une approche basée sur une étude multi-échelle des moments invariants. Les résultats expérimentaux montrent que la méthode des moments 3D de Gauss-Hermite est plus performante que les autres algorithmes populaires.Nous avons également abordé l'analyse des faciès sismiques basée sur les caractéristiques du vecteur à partir des moments 3D de Gauss -Hermite, et la méthode de Cartes Auto-organisatrices avec techniques de visualisation de données. L'excellent résultat de l'analyse des faciès montre que l'environnement intégré donne une meilleure performance dans l'interprétation de la structure des clusters.Enfin, nous introduisons le traitement parallèle et la visualisation de volume. En profitant des nouvelles performances par les technologies multi-threading et multi-cœurs dans le traitement et l'interprétation de données sismiques, nous calculons efficacement des attributs sismiques et nous suivons l'horizon. Nous discutons également l'algorithme de rendu de volume basé sur le moteur Open-Scene-Graph qui permet de mieux comprendre la structure de données sismiques. / Moments have been extensively used in pattern recognition and image processing. In this thesis, we focus our attention on the study of 3D orthogonal Gaussian-Hermite moments, 2D and 3D Gaussian-Hermite moment invariants, fast algorithm of coherency attribute, and applications of seismic interpretation using moments methodology.We conduct seismic horizon auto-tracking methods from Gaussian-Hermite moments and moment invariants. We introduce multi-scale moment invariants approach. The experimental results show that method of 3D Gaussian-Hermite moments performs better than the most popular methods.We also approach seismic facies analysis based on feature vectors from 3D Gaussian-Hermite moments, and Self-Organizing Maps method with data visualization techniques. The excellent result shows that the integrated environment gives the best performance in interpreting the correct cluster structure.Finally, we introduce the parallel processing and volume visualization. Taking advantage of new performances by multi-threading and multi-cores technologies into seismic interpretation, we efficiently compute the seismic attributes and track the horizon. We also discuss volume rendering algorithm based on Open-Scene-Graph engine which provides better insight into the structure of seismic data.