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The Triassic time scale is poorly constrained due to a paucity of high-precision radiometric ages. We present a [sup.206]Pb/[sup.238]U age of 230.91 [+ or -] 0.33 Ma (error includes all known sources) for zircon from an ash bed in the upper Carnian (Upper Triassic) of southern Italy that requires a major revision of the Triassic time scale. For example, the Norian stage is lengthened to more than 20 m.y. The section containing the ash bed is correlated with other Tethyan sections and, indirectly, with the Newark astronomical polarity time scale (APTS). The dating provides also a minimum age for some important climatic and biotic events that occurred during the Carnian. We note a coincidence between these events and the eruption of the large igneous province of Wrangellia, but the possible link between volcanism and climatic and biotic events requires further scrutiny. Keywords: geochronology, geologic time scale, Late Triassic, dinosaurs, calcareous nannoplankton, large igneous provinces.

An intelligent environment called SmartOffice is described. SmartOffice anticipates user intentions anc communicates useful information.

The problem of the local scale parameter selection for recognition techniques based on Guassian derivatives is addressed. The study shows promising results of recognition under variable scale and the results demonstrate that the approach holds promise for real-world applications.

An augmented reality tool for collaborative work called the MagicBoard, based on an ordinary white board, which is enhanced by a video-projector and steerable camera is described. Findings show that the white board scanner eliminates global luminosity differences by adaptive thresholding and the result can serve to digitize the content of the board.

A technique for visual recognition in which the appearance of objects is represented by families of surfaces in a local appearance space is presented. The results show that in many common situations, a single window is sufficient to obtain the correct recognition and the confidence of a recognition is easily estimated from the distance form the point to the surface, and the uniqueness determined by the number of surfaces which lie near the point.

U-Pb isotopic data and field relationships are used to outline the Paleoproterozoic geologic history of the Monashee complex, the largest of three Paleoproterozoic exposures in the Canadian Cordillera and one of the westernmost exposures of crystalline basement in North America. The effects of paleoproterozoic tectonism are best preserved in deep structural levels of the complex, where over-printing related to high-grade Cordilleran (early Tertiary) metamorphism and deformation was incomplete. Determination of precise crystallization ages is hindered by the U-Pb age discordance in the zircon, monazite, and titanite; the discordance is attributed to inherited Pb in some of the grains and to Pb loss, overgrowth, and recrystallization that occurred during one or more thermal overprints. Igneous crystallization ages are interpreted from the upper intercepts of linear arrays that are defined by three or more analyses. Varying degrees of confidence are attributed to the ages based on the probability of inheritance. Large bodies of augen orthogneiss and granodioritic orthogneiss yield precise igneous crystallization ages of 2077 +/- 2 and 1862 +/- 1 ma, respectively. Crystallization ages of about 2.27 and 2.10 Ga are interpreted with less certainty from dioritic orthogneiss and granitic orthogneiss, respectively. Deformation associated with a migmatitic gneissosity occurred after intrusion of the 2077 +/- Ma augen gneiss, the youngest dated rock that contains the fabric, and before intrusion of a 1848 +/- 3 ma granite, the oldest confidently dated rock that postdates the fabric. Postdeformational pegmatite dikes are dated as 1845 +/- 3 and 1836 +/- 2 ma. Metamorphism is interpreted as occurring during monazite growth at 2060 +/- Ma in pelitic schist and during titanite growth at ca. 1.85 Ga in amphibolitic gneiss. The gneisses are basement to an unconformably overlying cover sequence, the lower part of which was deposited prior to intrusion of a 1852 +/- 4 Ma pegmatite. There is sufficient age resolution on the intrusive rocks to conclude that Monashee basement has affinities with other Paleoproterozoic exposures in the Cordillera and the western Canadian shield. The knowledge that a paleoproterozoic geologic history can be elucidated through the Cordilleran overprint suggests that older histories may be preserved in the other Paleoproterozoic exposures in the Cordillera.

A study was conducted to develop mobile robot position estimation based on a principal component evaluation of laser range information. The relative position and rotation at which scans best overlap were determined by scan correlation while a synthetic scan generator was used to obtain a sample of possible range data measurements. Results indicated that the approach is computationally efficient and robust to occlusion errors.

An analogy between an object recognition process and the transmission of information through a communication channel is presented based on the statistical representation of 3D objects by a collection of multidimensional receptive field histograms. Through the analogy, the capacity, redundancy, transinformation and efficiency of the object recognition process can either be defined or calculated. Thus, an active object recognition algorithm that is able to resolve the ambiguities of a single-view recognition algorithm has been developed.

Computer vision is essential in the interaction between man and machine. Computer vision and video projection allow a human to use convenient objects as digital input devices. Computer vision techniques for watching hands and recognizing gestures as well as detecting, tracking and recognizing faces were described. These techniques, when integrated with real time image processing and active control of camera parameters, can reduce the communications bandwidth needed for videophone and videoconference applications.

A study was conducted of the supervised learning for perception to action mapping for a mobile robot. The 'grow and learn' (GAL) network was chosen as the neural approach for supervised learning of a function for its incrementality and flexibility. The results indicate that this type of learning is possible using a GAL network because the GAL network allows the adaptation of the complexity of the system to the complexity of the task.

A reactive vision process is developed to integrate and control the operating visual processes of robots. The visual processes are represented by transformations which map signals from virtual sensors into commands. The method follows the behavioral approach to manipulation and mobility. Signals from the supervisory controller and those obtained from perception regulate the transition between the visual processes. Visual systems with various visual abilities can be constructed in a learnable and scalable way.

The concept of active control of perceptions emerged from the Second International Symposium on Intelligent Robotics Systems held in Grenoble, France from July 11 to 15, 1994. Two major issues were discussed, the problems of describing the transformation from perception to action and position estimation regarding navigation system. The idea of multiple representations to form a composite model from various sensors emerged during the symposium.

Igneous, stratigraphic, metamorphic and deformational links reveal the Clachnacudainn terrane in the southern Omineca Belt as an integral part of the overlying Selkirk allochthon. Tectonic links suggest a similar tectonic history for the Clachnacudainn terrane and the Selkirk allochthon. The Standfast Creek fault has little tectonic significance in comparison with other faults in the southern Omineca belt. Presence of Clachnacudainn igneous complex in the northern part of the terrane is a major aspect, which differentiates the terrane from the rest of the Selkirk allochthon east of the Monashee complex.

Autonomous mobile robots are navigated in partially-known environments by a navigation planning algorithm applied to discrete workspaces. 'Efficient path' format is applied to the first search algorithm to solve multiple constraints imposed by environmental specifications. The path computation depends on state representation that solves the constraints. The algorithm complexity properties are similar to those of the A* algorithm.