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 Expert Systems


Hierarchical Decision Ensembles- An inferential framework for uncertain Human-AI collaboration in forensic examinations

arXiv.org Artificial Intelligence

Forensic examination of evidence like firearms and toolmarks, traditionally involves a visual and therefore subjective assessment of similarity of two questioned items. Statistical models are used to overcome this subjectivity and allow specification of error rates. These models are generally quite complex and produce abstract results at different levels of the analysis. Presenting such metrics and complicated results to examiners is challenging, as examiners generally do not have substantial statistical training to accurately interpret results. This creates distrust in statistical modelling and lowers the rate of acceptance of more objective measures that the discipline at large is striving for. We present an inferential framework for assessing the model and its output. The framework is designed to calibrate trust in forensic experts by bridging the gap between domain specific knowledge and predictive model results, allowing forensic examiners to validate the claims of the predictive model while critically assessing results.


Cross-Domain Reasoning via Template Filling

arXiv.org Artificial Intelligence

In this paper, we explore the ability of sequence to sequence models to perform cross-domain reasoning. Towards this, we present a prompt-template-filling approach to enable sequence to sequence models to perform cross-domain reasoning. We also present a case-study with commonsense and health and well-being domains, where we study how prompt-template-filling enables pretrained sequence to sequence models across domains. Our experiments across several pretrained encoder-decoder models show that cross-domain reasoning is challenging for current models. We also show an in-depth error analysis and avenues for future research for reasoning across domains


TargetUM: Targeted High-Utility Itemset Querying

arXiv.org Artificial Intelligence

Traditional high-utility itemset mining (HUIM) aims to determine all high-utility itemsets (HUIs) that satisfy the minimum utility threshold (\textit{minUtil}) in transaction databases. However, in most applications, not all HUIs are interesting because only specific parts are required. Thus, targeted mining based on user preferences is more important than traditional mining tasks. This paper is the first to propose a target-based HUIM problem and to provide a clear formulation of the targeted utility mining task in a quantitative transaction database. A tree-based algorithm known as Target-based high-Utility iteMset querying using (TargetUM) is proposed. The algorithm uses a lexicographic querying tree and three effective pruning strategies to improve the mining efficiency. We implemented experimental validation on several real and synthetic databases, and the results demonstrate that the performance of \textbf{TargetUM} is satisfactory, complete, and correct. Finally, owing to the lexicographic querying tree, the database no longer needs to be scanned repeatedly for multiple queries.


Creating and evolving knowledge graphs at scale for explainable AI - Safe & Trusted AI

#artificialintelligence

Knowledge graphs and knowledge bases are forms of symbolic knowledge representations used across AI applications. Both refer to a set of technologies that organise data for easier access, capture information about people, places, events, and other entities of interest, and forge connections between them. As AI (re-)conquered the world, symbolic knowledge representations became ubiquitous, and are now extensively used in everything from search engines and chatbots to product recommenders and autonomous systems, especially in the context of neuro-symbolic approaches. Knowledge engineering is the field that encompasses technical and social aspects related to building knowledge-based AI systems. In its most recent manifestation, it involves complex, human-machine workflows including knowledge acqusition from experts, crowdsourced entity typing and reconciliation, argumentation and discussion support, information extraction algorithms across different data modalities, and database lifting.


Conditional Inference and Activation of Knowledge Entities in ACT-R

arXiv.org Artificial Intelligence

Activation-based conditional inference applies conditional reasoning to ACT-R, a cognitive architecture developed to formalize human reasoning. The idea of activation-based conditional inference is to determine a reasonable subset of a conditional belief base in order to draw inductive inferences in time. Central to activation-based conditional inference is the activation function which assigns to the conditionals in the belief base a degree of activation mainly based on the conditional's relevance for the current query and its usage history.


Contrastive Explanations of Plans through Model Restrictions

Journal of Artificial Intelligence Research

In automated planning, the need for explanations arises when there is a mismatch between a proposed plan and the user’s expectation. We frame Explainable AI Planning as an iterative plan exploration process, in which the user asks a succession of contrastive questions that lead to the generation and solution of hypothetical planning problems that are restrictions of the original problem. The object of the exploration is for the user to understand the constraints that govern the original plan and, ultimately, to arrive at a satisfactory plan. We present the results of a user study that demonstrates that when users ask questions about plans, those questions are usually contrastive, i.e. “why A rather than B?”. We use the data from this study to construct a taxonomy of user questions that often arise during plan exploration. Our approach to iterative plan exploration is a process of successive model restriction. Each contrastive user question imposes a set of constraints on the planning problem, leading to the construction of a new hypothetical planning problem as a restriction of the original. Solving this restricted problem results in a plan that can be compared with the original plan, admitting a contrastive explanation. We formally define model-based compilations in PDDL2.1 for each type of constraint derived from a contrastive user question in the taxonomy, and empirically evaluate the compilations in terms of computational complexity. The compilations were implemented as part of an explanation framework supporting iterative model restriction. We demonstrate its benefits in a second user study.


SQALER: Scaling Question Answering by Decoupling Multi-Hop and Logical Reasoning

arXiv.org Artificial Intelligence

State-of-the-art approaches to reasoning and question answering over knowledge graphs (KGs) usually scale with the number of edges and can only be applied effectively on small instance-dependent subgraphs. In this paper, we address this issue by showing that multi-hop and more complex logical reasoning can be accomplished separately without losing expressive power. Motivated by this insight, we propose an approach to multi-hop reasoning that scales linearly with the number of relation types in the graph, which is usually significantly smaller than the number of edges or nodes. This produces a set of candidate solutions that can be provably refined to recover the solution to the original problem. Our experiments on knowledge-based question answering show that our approach solves the multi-hop MetaQA dataset, achieves a new state-of-the-art on the more challenging WebQuestionsSP, is orders of magnitude more scalable than competitive approaches, and can achieve compositional generalization out of the training distribution.


Why is XAI at core for the success of 'AI' in Financial Institutions? And what is Arya-xAI?

#artificialintelligence

It is imperative for next generation applications to have AI at the core. With almost all major tech players offering AI enabled solutions, we see it as a default feature in any upcoming software products. Many financial institutions have already started their innovation programs by automating existing rule sets with machine learning models to automate/augment existing processes. These models can make automated decisions across vast quantities of data. Even then, organizations are somewhat apprehensive in deploying these systems into the core process, since AI solutions carry a, probably justified, reputation for being'black boxes' characterized by poor transparency.


Knowledgeable Machine Learning for Natural Language Processing

Communications of the ACM

In the past decades, one line has run through the entire research spectrum of natural language processing (NLP)--knowledge. With various kinds of knowledge, such as linguistic knowledge, world knowledge, and commonsense knowledge, machines can understand complex semantics at different levels. In this article, we introduce a framework named "knowledgeable machine learning" to revisit existing efforts to incorporate knowledge in NLP, especially the recent breakthroughs in the Chinese NLP community. Since knowledge is closely related to human languages, the ability to capture and utilize knowledge is crucial to make machines understand languages. As shown in the accompanying figure, the symbolic knowledge formalized by human beings was widely used by NLP researchers before 1990, such as applying grammar rules for linguistic theories3 and building knowledge bases for expert systems.1


A Generic Knowledge Based Medical Diagnosis Expert System

arXiv.org Artificial Intelligence

Expert system can process large amounts of known information and apply reasoning capabilities to provide conclusions. An expert system is a system that employs human knowledge captured in an automated system to solve problems that typically require human expertise. In this paper we propose the design and development of a medical knowledge based system (MKBS) for disease diagnosis from symptoms. It provides rich features for searching properties like symptoms, treatments, hierarchical clusters of particular diseases. The system supports a knowledge construction module and an inference engine module. The knowledge construction was built on a concept of rules, which was represented in a tree structure, and properties of a particular disease were stored as a semantic net.