This paper presents an implemented system for recognizing the occurrence of events described by simple spatial-motion verbs in short image sequences. The semantics of these verbs is specified with event-logic expressions that describe changes in the state of force-dynamic relations between the participants of the event. An efficient finite representation is introduced for the infinite sets of intervals that occur when describing liquid and semi-liquid events. Additionally, an efficient procedure using this representation is presented for inferring occurrences of compound events, described with event-logic expressions, from occurrences of primitive events. Using force dynamics and event logic to specify the lexical semantics of events allows the system to be more robust than prior systems based on motion profile. 1.

This paper outlines a framework for analyzing how decision makers achieve “situation awareness ” in complex, dynamic and uncertain situations. We use this framework to analyze a typical case of human “error ” in the command and control of a complex system. Our analysis shows that decision errors in this and other cases can be characterized as “normal ” (i.e., rational) consequences of the decision makers’ mental models. We conclude by suggesting that a mental models approach can provide unifying insights into the “heuristics and biases ” proposed by previous researchers. _____________________________________________________________________________________________ 1

As powerful and affordable computers and sensors become virtually om-nipresent, constructing highly intelligent and convenient computation systems has never been so promising. Vision holds great promise in building advanced human-computer interaction (HCI) systems. We investigate different techniques to integrate passive vision into various interaction environments. First, we propose a novel approach to integrate visual tracking into a haptics systems. Traditional haptic environments require that the user must be attached to the haptic device at all times, even though force feedback is not always being rendered. We design and implement an augmented reality system called VisHap that uses visual tracking to seamlessly integrate force feedback with tactile feedback to generate a “complete ” haptic experience. The VisHap framework allows the user to interact with combinations of virtual and real objects naturally, thereby combining active and passive haptics. The flexibility and extensibility of our framework is promising in that it supports many interaction modes and allows further integration with other

In this paper, we present a practical approach for integrating computer vision techniques into human-computer interaction systems. Our techniques are applicable in conventional 2D windowing environments and advanced 3D scenarios. The method is transparent in the sense that no modification (e.g. no re-compilation) of the underlying application software is required. To realize this functionality, we propose an interface scanner that analyzes the input event requirements of a given running application and translates them into event descriptions available from our vision-based HCI framework. We include a description of our vision system that extends the basic set of events like ButtonPressEvent, MotionEvent, ButtonReleaseEvent by more abstract events like TurnDialEvent, DeleteEvent. We describe our framework for 2D interfaces based on the Unix X11 API and for 3D interfaces which use OpenGL. We provide an analysis of the stability and accuracy of the framework for our current implementation. 1.