Active Model Set Research Articles

Fast Variable-Structure Multiple-Model Estimation Using Modified Likely-Model Set Tracker

A new variable-structure multiple-model (VSMM) estimator which is generally applicable to most hybrid estimation problems is fully developed in this paper. Modified likely-model set (MLMS) algorithm is proposed by introducing the concept of central models in model set adoption process. A set of models that are more probable match the true system mode at any given time plus a set of central models are implemented as active model set. Small decision delay and therefore fast tracking is the major priority of the proposed algorithm. The generality and simplicity in the design and use are other merits of the proposed method. A well-known example of tracking a maneuvering target is given to illustrate the effectiveness of the proposed method in comparison with other VSMM estimators.

Conditions of Archean granulite metamorphism in the Godthab‐Fiskenaesset region, southern West Greenland

The Nordlandet peninsula (Akia terrane) and the Tasiusarsuaq terrane in southern West Greenland were metamorphosed to granulite facies at 3.0 and 2.8 Ga respectively. Temperatures of metamorphism are estimated using magnetite + ilmenite, garnet + orthopyroxene, garnet + clinopyroxene and garnet + biotite thermometers. Barometry has been carried out in the two terranes using eight different garnet barometers. A uniform set of activity models for all minerals, including the garnet activity model of Newton et al. (1986), is applied to each barometer in order to permit comparison. Pressure estimates using the different barometers are generally quite consistent (±1.5 kbar). Use of the Newton et al. (1986) garnet activity data results in pressures similar to those obtained using other garnet activity models.Peak metamorphic conditions on the Nordlandet peninsula are estimated to have been 800 ± 50°C, 7.9 ± 1.0 kbar. Values of logfO2 are estimated to have been 1.1 to 2.0 above the quartz + magnetite + fayalite buffer from assemblages of magnetite + ilmenite and quartz + magnetite + ferrosilite. Peak metamorphic conditions in the Tasiusarsuaq terrane are estimated to have been 780 ± 50°C, 8.9 ± 1.0 kbar. Estimates of fH2O and fCO2 using biotite, amphibile, grossular + anorthite and grossular + scapolite equilibria are low in both terranes. These results suggest that granulite metamorphism was fluid absent in both terranes, and that the metamorphism in the Akia terrane and possibly also in the Tasiusarsuaq terrane was initiated by the injection of large volumes of magma into the lower crust.