Attribute-based access control (ABAC) is a general access control model that subsumes numerous earlier access control models. Its increasing popularity stems from the intuitive generic structure of granting permissions based on application and domain attributes of users, subjects, objects, and other entities in the system. Multiple formal and informal languages have been developed to express policies in terms of such attributes. The utility of ABAC policy languages is potentially undermined without a properly formalized underlying model. The high-level structure in a majority of ABAC models consists of sets of tokens and sets of sets, expressions that demand that the reader unpack multiple levels of sets and tokens to determine what things mean. The resulting reduced readability potentially endangers correct expression, reduces maintainability, and impedes validation. These problems could be magnified in models that employ nonuniform representations of actions and their governing policies. We propose to avoid these magnified problems by recasting the high-level structure of ABAC models in a logical formalism that treats all actions (by users and others) uniformly and that keeps existing policy languages in place by interpreting their attributes in terms of the restructured model. In comparison to existing ABAC models, use of a logical language for model formalization, including hierarchies of types of entities and attributes, promises improved expressiveness in specifying the relationships between and requirements on application and domain attributes. A logical modeling language also potentially improves flexibility in representing relationships as attributes to support some widely used policy languages. Consistency and intelligibility are improved by using uniform means for representing different types of controlled actions---such as regular access control actions, administrative actions, and user logins---and their governing policies. Logical languages also provide a well-defined denotational semantics supported by numerous formal inference and verification tools.

A key challenge in Multi-agent Plan Recognition (MPAR) is effectively pruning the large search space of potential goal / team compositions because multi-agent scenarios distribute actions/observables across agents. This additional dimension also makes creating a priori plan libraries difficult. In this paper, we describe our strategy for discrete Multi-agent Plan Recognition as Planning (MAPRAP), which extends Ramirez and Geffner’s Plan Recognition as Planning (PRAP) approach into multi-agent domains. MAPRAP (like PRAP) uses a planning domain (not a library) to synthesize and compare utility costs of plan instances that incorporate potential goals and previous observables to identify the plan being carried out by teams of agents. This initial discrete implementation of MAPRAP includes two pruning strategies to address the explosion of hypotheses. We establish a performance profile for discrete MAPRAP using the well-known multi-agent blocks-world benchmark domain. We varied the number of teams, agent count, and goal sizes. We measured accuracy, precision, and recall at each time step. For pruning efficiency, we compare two strategies. In the more aggressive case our multi-agent team blocks scenarios averaged 1.05 plans synthesized per goal per time step (compared to 0.56 for single agent scenarios) demonstrating feasibility of MAPRAP and benchmarking for future improvements.

BACKGROUND: Discovering causal genetic variants from large genetic association studies poses many difficult challenges. Assessing which genetic markers are involved in determining trait status is a computationally demanding task, especially in the presence of gene-gene interactions. RESULTS: A non-parametric Bayesian approach in the form of a Bayesian neural network is proposed for use in analyzing genetic association studies. Demonstrations on synthetic and real data reveal they are able to efficiently and accurately determine which variants are involved in determining case-control status. By using graphics processing units (GPUs) the time needed to build these models is decreased by several orders of magnitude. In comparison with commonly used approaches for detecting interactions, Bayesian neural networks perform very well across a broad spectrum of possible genetic relationships. CONCLUSIONS: The proposed framework is shown to be a powerful method for detecting causal SNPs while being computationally efficient enough to handle large datasets.

Software engineers must systematically account for the broad scope of environmental behavior, including nonfunctional requirements, intended to coordinate the actions of stakeholders and software systems. The Inquiry Cycle Model (ICM) provides engineers with a strategy to acquire and refine these requirements by having domain experts answer six questions: who, what, where, when, how, and why. Goal-based requirements engineering has led to the formalization of requirements to answer the ICM questions about when , how , and why goals are achieved, maintained, or avoided. In this article, we present a systematic process called Semantic Parameterization for expressing natural language domain descriptions of goals as specifications in description logic. The formalization of goals in description logic allows engineers to automate inquiries using who , what , and where questions, completing the formalization of the ICM questions. The contributions of this approach include new theory to conceptually compare and disambiguate goal specifications that enables querying goals and organizing goals into specialization hierarchies. The artifacts in the process include a dictionary that aligns the domain lexicon with unique concepts, distinguishing between synonyms and polysemes, and several natural language patterns that aid engineers in mapping common domain descriptions to formal specifications. Semantic Parameterization has been empirically validated in three case studies on policy and regulatory descriptions that govern information systems in the finance and health-care domains.

This article examines prospects for theories and methods of preferences, both in the specific sense of the preferences of the ideal rational agents considered in economics and decision theory and in the broader interplay between reasoning and rationality considered in philosophy, psychology, and artificial intelligence. Modern applications seek to employ preferences as means for specifying, designing, and controlling rational behaviors as well as descriptive means for understanding behaviors. We seek to understand the nature and representation of preferences by examining the roles, origins, meaning, structure, evolution, and application of preferences.

Ceteris paribus (all‐else equal) preference statements concisely represent preferences over outcomes or goals in a way natural to human thinking. Although deduction in a logic of such statements can compare the desirability of specific conditions or goals, many decision‐making methods require numerical measures of degrees of desirability. To permit ceteris paribus specifications of preferences while providing quantitative comparisons, we present an algorithm that compiles a set of qualitative ceteris paribus preferences into an ordinal utility function. Our algorithm is complete for a finite universe of binary features. Constructing the utility function can, in the worst case, take time exponential in the number of features, but common independence conditions reduce the computational burden. We present heuristics using utility independence and constraint‐based search to obtain efficient utility functions.

Logical epistemology unduly sways theories of thinking that formulate problems of nonmonotonic reasoning as issues of nondeductive operations on logically phrased beliefs, because the fundamental concepts underlying such reasoning have little to do w

The economic theory of rationality promises to equal mathematical logic in its importance for the mechanization of reasoning. We survey the growing literature on how the basic notions of probability, utility, and rational choice, coupled with practical limitations on information and resources, influence the design and analysis of reasoning and representation systems.

Common sense sometimes predicts events to be likely or unlikely rather than merely possible. We extend methods of qualitative reasoning to predict the relative likelihoods of possible qualitative behaviors by viewing the dynamics of a system as a Markov chain over its transition graph. This involves adding qualitative or quantitative estimates of transition probabilities to each of the transitions and applying the standard theory of Markov chains to distinguish persistent states from transient states and to calculate recurrence times, settling times, and probabilities for ending up in each state. Much of the analysis depends solely on qualitative estimates of transition probabilities, which follow directly from theoretical considerations and which lead to qualitative predictions about entire classes of systems. Quantitative estimates for specific systems are derived empirically and lead to qualitative and quantitative conclusions, most of which are insensitive to small perturbations in the estimated transition probabilities. The algorithms are straightforward and efficient.

It is commonplace in artificial intelligence to divide an agent's explicit beliefs into two parts: the beliefs explicitly represented or manifest in memory, and the implicitly represented or constructive beliefs that are repeatedly reconstructed when needed rather than memorized. Many theories of knowledge view the relation between manifest and constructive beliefs as a logical relation, with the manifest beliefs representing the constructive beliefs through a logic of belief. This view, however, limits the ability of a theory to treat incomplete or inconsistent sets of beliefs in useful ways. We argue that a more illuminating view is that belief is the result of rational representation. In this theory, the agent obtains its constructive beliefs by using its manifest beliefs and preferences to rationally (in the sense of decision theory) choose the most useful conclusions indicated by the manifest beliefs.

Elements of the artificial intelligence approach to expert systems offer great productivity advantages over traditional approaches to application systems development, even though the end result may be a program employing no AI techniques. These productivity advantages are the hidden truths behind the "myth" that symbolic reasoning programs are better than ordinary ones.