Assessing Interaction Networks with Applications to Catastrophe Dynamics and Disaster Management

In this paper we present a versatile method for the investigation of interaction networks and show how to use it to assess effects of indirect interactions and feedback loops. The method allows to evaluate the impact of optimization measures or failures on the system. Here, we will apply it to the investigation of catastrophes, in particular to the temporal development of disasters (catastrophe dynamics). The mathematical methods are related to the master equation, which allows the application of well-known solution methods. We will also indicate connections of disaster management with excitable media and supply networks. This facilitates to study the effects of measures taken by the emergency management or the local operation units. With a fictious, but more or less realistic example of a spreading epidemic disease or a wave of influenza, we illustrate how this method can, in principle, provide decision support to the emergency management during such a disaster. Similar considerations may help to assess measures to fight the SARS epidemics, although immunization is presently not possible

Robotic software for the mini-mover 5 robot arm

The aim of the project is to design and implement software on a MOTOROLA M68000 16 bit microprocessor to control a MINI-MOVER 5 robot arm

Environment exploration and path planning algorithms for mobile robot navigation using sonar

The work reported in this thesis is motivated by the need to construct a navigation system for mobile robots which can operate in unknown and partially known environments, and which has the capability to progressively learn an environment A new environment mapping procedure is described that constructs high resolution maps of an environment using ultrasonic range sensing. The ultrasonic range maps are converted into quadtrees. Quadtrees are used by the navigation system as the data structure that models the environment. This thesis presents a new algorithm for a mobile robot to explore an unknown environment using the quadtree data structure and the distance transform path planning methodology. Past approaches to robot path planning have concentrated on finding the shortest path to a goal. A path planner should also support finding a variety of other kinds of paths to a goal. For example a path planner could support finding conservative , adventurous and safe paths. Conservative paths favour known areas, while adventurous paths avoid known areas. Safe paths keep a safe distance from obstacles, while simultaneously keeping the path length to the goal as short as possible. It is shown that the new mobile robot exploration algorithm can generate a wide variety of path planning behaviours by a novel use of distance transforms. Much of the research effort into path planning for mobile robots has concentrated on the problem of finding paths by translation of the robot body only. The problem of finding paths which require the rotation of the robot body have been largely ignored. This thesis presents an new algorithm for path planning with three degrees of freedom which is based upon an extension to the safe path planning behaviour. Finally it is shown that the new algorithms that have been presented are computationally efficient, and have desirable features that are absent from other path planning algorithms

Finger track - a robust and realtime gesture interface

Real-time computer vision combined with robust gesture recognition provides a natural alternative to traditional computer interfaces. Human users have plenty of experience with actions and the manipulation of objects requiring finger movement. In place of a mouse, users could use their hands to select and manipulate data. This paper presents a first step in this approach using a finger as a pointing and selection device. A major feature of a successful tracking system is robustness. The system must be able to acquire tracked features upon startup, and reacquire them if lost during tracking. Reacquisition should be fast and accurate (i.e. it should pick up the correct feature). Intelligent search algorithms are needed for speedy, accurate acquisition of lost features with the frame. The prototype interface presented in this paper is based on finger tracking as a means of input to applications. The focus of the discussion is how the system can be made to perform robustly in real-time. Dynamically distributed search windows are defined for searching within the frame. The location and number of search windows are dependent on the confidence in the tracking of features. Experimental results showing the effectiveness of these techniques are presented

Mobile Robot Navigation Exploration Algorithm

This paper will present an algorithm for path planning to a goal with a mobile robot in an unknown environment. The robot maps the environment only to the extent that is necessary to achieve the goal. Mapping is achieved using tactile sensing while the robot is executing a path to the specified goal. Paths are generated by treating unknown regions in the environment as free space. As obstacles are encountered en route to a goal, the model of the environment is updated and a new path to the goal is planned and executed. Initially the paths to the goal generated by this algorithm will be negotiable paths. However as the robot acquires more knowledge about the environment, the length of the planned paths will be optimised. The optimisation criteria can be modified to favour or avoid unexplored regions in the environment. The algorithm presented in this paper makes use of the quadtree data structure to model the environment and uses the distance transform methodology to generate paths for ..

3-D Facial Pose and Gaze Point Estimation using a Robust Real-Time Tracking Paradigm

Facial pose and gaze point are fundamental to any visually directed human-machine interface. In this paper, we propose a system capable of tracking a face and estimating the 3-D pose and the gaze point all in a real-time video stream of the head. This is done by using a 3-D model together with multiple triplet triangulation of feature positions assuming an affine projection. Using feature-based tracking the calculation of a 3-D eye gaze direction vector is possible even with head rotation and using a monocular camera. The system is also able to automatically initialise the feature tracking and to recover from total tracking failures which can occur when a person becomes occluded or temporarily leaves the image. 1. Introduction Human-machine interfaces need to interact with users in more natural ways than at present. Natural interaction consists of two major parts, natural language understanding and synthesis on one side and visual observation of the user's body pose and gestures on th..