Steps toward a theoretic foundation for complex knowledge-based CAI.

Here we consider the logical bases for rules: what kinds of arguments justify the rules, and what is their relation to a mechanistic model of the domain? We use the terms "explain" and "justify" synonymously, although the sense of "making clear what is not understood" (explain) is intended more than "vindicating, showing to be right or lawful" (justify).

This article contains detailed proofs and additional examples related to the UAI-2013 submission `Learning Sparse Causal Models is not NP-hard'. It describes the FCI+ algorithm: a method for sound and complete causal model discovery in the presence of latent confounders and/or selection bias, that has worst case polynomial complexity of order $N^{2(k+1)}$ in the number of independence tests, for sparse graphs over $N$ nodes, bounded by node degree $k$. The algorithm is an adaptation of the well-known FCI algorithm by (Spirtes et al., 2000) that is also sound and complete, but has worst case complexity exponential in $N$.

This paper introduces a novel encoding of Model Based Diagnosis (MBD) to Boolean Satisfaction (SAT) focusing on minimal cardinality diagnosis. The encoding is based on a combination of sophisticated MBD preprocessing algorithms and the application of a SAT compiler which optimizes the encoding to provide more succinct CNF representations than obtained with previous works. Experimental evidence indicates that our approach is superior to all published algorithms for minimal cardinality MBD. In particular, we can determine, for the first time, minimal cardinality diagnoses for the entire standard ISCAS-85 and 74XXX benchmarks. Our results open the way to improve the state-of-the-art on a range of similar MBD problems.

We show how, and under which conditions, the equilibrium states of a first-order Ordinary Differential Equation (ODE) system can be described with a deterministic Structural Causal Model (SCM). Our exposition sheds more light on the concept of causality as expressed within the framework of Structural Causal Models, especially for cyclic models.

In several applications of automatic diagnosis and active learning a central problem is the evaluation of a discrete function by adaptively querying the values of its variables until the values read uniquely determine the value of the function. In general, the process of reading the value of a variable might involve some cost, computational or even a fee to be paid for the experiment required for obtaining the value. This cost should be taken into account when deciding the next variable to read. The goal is to design a strategy for evaluating the function incurring little cost (in the worst case or in expectation according to a prior distribution on the possible variables' assignments). Our algorithm builds a strategy (decision tree) which attains a logarithmic approxima- tion simultaneously for the expected and worst cost spent. This is best possible under the assumption that $P \neq NP.$

Blind spot check is important driving activity that is a good indicator of drivers’ proficiency and vigilance. By recognizing the blind spot check activity with drivers, it is possible to quantify and qualify the proficiency of the drivers, but also to cross validate this information with other data such the fatigue level. Thus, in this paper, we present a blind spot check activity recognition system where decision tree classifiers are modeled for each drivers and are used to automatically recognize the blind spot checks.

We propose a combination of AI techniques to improve softwaretesting. When a test fails, a model-based diagnosis(MBD) algorithm is used to propose a set of possible explanations.We call these explanations diagnoses. Then, a planningalgorithm is used to suggest further tests to identify thecorrect diagnosis. A tester preforms these tests and reportstheir outcome back to the MBD algorithm, which uses thisinformation to prune incorrect diagnoses. This iterative processcontinues until the correct diagnosis is returned. We callthis testing paradigm Test, Diagnose and Plan (TDP). Severaltest planning algorithms are proposed to minimize the numberof TDP iterations, and consequently the number of testsrequired until the correct diagnosis is found. Experimentalresults show the benefits of using an MDP-based planning algorithmsover greedy test planning in three benchmarks.

Fault diagnosis of analogue linear systems poses many challenges, such as the size of the search space that must be explored and the possibility of simulation instabilities introduced by particular fault classes. We study a novel algorithm that addresses both problems. This algorithm dynamically modifies the simulation model during diagnosis by pruning parametrized components that cause discontinuity in the model. We provide a theoretical framework for predicting the speedups, which depends on the topology of the model. We empirically validate the theoretical predictions through extensive experimentation on a benchmark of circuits.

Therefore, diagnostic algorithms must reason backwards from symptoms to causes. For example, determining that a dead battery is the cause of your car not starting in the morning (and not the wiring or the ignition switch). The domains of diagnostic algorithms includes analog and digital circuits, software systems, thermal systems, biological systems, and physical mechanisms. The same classes of diagnostic algorithms can apply in all domains. Diagnostic algorithms make observations, often in real time, of a system being diagnosed.