Impact estimation using data flows over attack graphs

We propose a novel approach to estimating the impact of an attack using a data model and an impact model on top of an attack graph. The data model describes how data flows between nodes in the network -- how it is copied and processed by softwares and hosts -- while the impact model models how exploitation of vulnerabilities affects the data flows with respect to the confidentiality, integrity and availability of the data. In addition, by assigning a loss value to a compromised data set, we can estimate the cost of a successful attack. We show that our algorithm not only subsumes the simple impact estimation used in the literature but also improves it by explicitly modeling loss value dependencies between network nodes. With our model, the operator will be able to use less time when comparing different security patches to a network

Assessing Security Risk to a Network Using a Statistical Model of Attacker Community Competence

We propose a novel approach for statistical risk modeling of network attacks that lets an operator perform risk analysis using a data model and an impact model on top of an attack graph in combination with a statistical model of the attacker community exploitation skill. The data model describes how data flows between nodes in the network -- how it is copied and processed by softwares and hosts -- while the impact model models how exploitation of vulnerabilities affects the data flows with respect to the confidentiality, integrity and availability of the data. In addition, by assigning a loss value to a compromised data set, we can estimate the cost of a successful attack. The statistical model lets us incorporate real-time monitor data from a honeypot in the risk calculation. The exploitation skill distribution is inferred by first classifying each vulnerability into a required exploitation skill-level category, then mapping each skill-level into a distribution over the required exploitation skill, and last applying Bayesian inference over the attack data. The final security risk is thereafter computed by marginalizing over the exploitation skill

Case-based reasoning combined with statistics for diagnostics and prognosis

Many approaches used for diagnostics today are based on a precise model. This excludes diagnostics of many complex types of machinery that cannot be modelled and simulated easily or without great effort. Our aim is to show that by including human experience it is possible to diagnose complex machinery when there is no or limited models or simulations available. This also enables diagnostics in a dynamic application where conditions change and new cases are often added. In fact every new solved case increases the diagnostic power of the system. We present a number of successful projects where we have used feature extraction together with case-based reasoning to diagnose faults in industrial robots, welding, cutting machinery and we also present our latest project for diagnosing transmissions by combining Case-Based Reasoning (CBR) with statistics. We view the fault diagnosis process as three consecutive steps. In the first step, sensor fault signals from machines and/or input from human operators are collected. Then, the second step consists of extracting relevant fault features. In the final diagnosis/prognosis step, status and faults are identified and classified. We view prognosis as a special case of diagnosis where the prognosis module predicts a stream of future features

Personalized Decentralized Communication

Search engines, portals and topic-centered web sites are all attempts to create more or less personalized web-services. However, no single service can in general fulfill all needs of a particular user, so users have to search and maintain personal profiles at several locations. We propose an architecture where each person has his own information management environment where all personalization is made locally. Information is exchanged with other’s if it’s of mutual interest that the information is published or received. We assume that users are self-interested, but that there is some overlap in their interests. Our recent work has focused on decentralized dissemination of information, specifically what we call decentralized recommender systems. We are investigating the behavior of such systems and have also done some preliminary work on the users’ information environment

Vision Guided Force Control in Robotics

One way to increase the flexibility of industrial robots in manipulation tasks is to integrate additional sensors in the control systems. Cameras are an example of such sensors, and in recent years there has been an increased interest in vision based control. However, it is clear that most manipulation tasks can not be solved using position control alone, because of the risk of excessive contact forces. Therefore, it would be interesting to combine vision based position control with force feedback. In this thesis, we present a method for combining direct force control and visual servoing in the presence of unknown planar surfaces. The control algorithm involves a force feedback control loop and a vision based reference trajectory as a feed-forward signal. The vision system is based on a constrained image-based visual servoing algorithm, using an explicit 3D-reconstruction of the planar constraint surface. We show how calibration data calculated by a simple but efficient camera calibration method can be used in combination with force and position data to improve the reconstruction and reference trajectories. The task chosen involves force controlled drawing on an unknown surface. The robot will grasp a pen using visual servoing, and use the pen to draw lines between a number of points on a whiteboard. The force control will keep the contact force constant during the drawing. The method is validated through experiments carried out on a 6-degree-of-freedom ABB Industrial Robot 2000

High-Speed Vision and Force Feedback for Motion-Controlled Industrial Manipulators

Over the last decades, both force sensors and cameras have emerged as useful sensors for different applications in robotics. This thesis considers a number of dynamic visual tracking and control problems, as well as the integration of these techniques with contact force control. Different topics ranging from basic theory to system implementation and applications are treated. A new interface developed for external sensor control is presented, designed by making non-intrusive extensions to a standard industrial robot control system. The structure of these extensions are presented, the system properties are modeled and experimentally verified, and results from force-controlled stub grinding and deburring experiments are presented. A novel system for force-controlled drilling using a standard industrial robot is also demonstrated. The solution is based on the use of force feedback to control the contact forces and the sliding motions of the pressure foot, which would otherwise occur during the drilling phase. Basic methods for feature-based tracking and servoing are presented, together with an extension for constrained motion estimation based on a dual quaternion pose parametrization. A method for multi-camera real-time rigid body tracking with time constraints is also presented, based on an optimal selection of the measured features. The developed tracking methods are used as the basis for two different approaches to vision/force control, which are illustrated in experiments. Intensity-based techniques for tracking and vision-based control are also developed. A dynamic visual tracking technique based directly on the image intensity measurements is presented, together with new stability-based methods suitable for dynamic tracking and feedback problems. The stability-based methods outperform the previous methods in many situations, as shown in simulations and experiments

Information Filtering with Collaborative Interface Agents

This report describes a distributed approach to social filtering based on the agent metaphor. Firstly, previous approaches are described, such as cognitive filtering and social filtering. Then a couple of previously implemented systems are presented and then a new system design is proposed. The main goal is to give the requirements and design of an agent-based system that recommends web-documents. The presented approach combines cognitive and social filtering to get the advantages from both techniques. Finally, a prototype implementation called WebCondor is described and results of testing the system are reported and discussed

Enhancing Web-Based Configuration with Recommendations and Cluster-Based Help

In a collaborative project with Tacton AB, we have investigated new ways of assisting the user in the process of on-line product configuration. A web-based prototype, RIND, was built for ephemeral users in the domain of PC configuration

Maximizing the Use of Computational Resources in Multi-Camera Feedback Control

In vision-based feedback control systems, the time to obtain sensor information is usually non-negligible, and these systems thereby possess fundamentally different timing behavior compared to standard real-time control applications. For many image-based tracking algorithms, however, it is possible to trade-off the computational time versus the accuracy of the produced position/orientation estimates.This paper presents a method for optimizing the use of computational resources in a multi-camera based positioning system. A simplified equation for the covariance of the position estimation error is calculated, which depends on the set of cameras used and the number of edge detection points in each image. An efficient algorithm for selection of a suitable subset of the available cameras is presented, which attempts to minimize the estimation covariance given a desired, pre-specified maximum input-output latency of the feedback control loop.Simulations have been performed that capture the real-time properties of the vision-based tracking algorithm and the effects of the timing on the performance of the control system. The suggested strategy has been compared with heuristic algorithms, and it obtains large improvements in estimation accuracy and performance for objects both in free motion and under closed-loop position control

Implementation Problems for Activated Sludge Controllers

The paper describes some problems that appear in the implementation of a computer control system in a wastewater treatment plant. The problems are related to the control authority of the actuators, the influence of the process design on the controller design, or the disturbance pattern. Some experience from two full scale activated sludge plants in Sweden are discussed