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Robustness, Adaptivity, and Resiliency Analysis

AAAI Conferences

In order to better understand the mechanisms that lead to resiliency in natural systems, to support decisions that lead to greater resiliency in systems we effect, and to create models that will utilized in highly resilient systems, methods for resiliency analysis will be required. Existing methods and technology for robustness analysis provide a foundation for a rigorous approach to resiliency analysis, but extensions are necessary to address the multiple time scales that must be modeled to understand highly adaptive systems. Further, if resiliency modeling is to be effective, it must be contextualized, requiring that the supporting software will need to mirror the systems being modeling by being pace layered and adaptive.


Toward a Computational Model of Narrative

AAAI Conferences

Narratives structure our understanding of the world and of ourselves. They exploit the shared cognitive structures of human motivations, goals, actions, events, and outcomes. We report on a computational model that is motivated by results in neural computation and captures fine-grained, context sensitive information about human goals, processes, actions, policies, and outcomes. We describe the use of the model in the context of a pilot system that is able to interpret simple stories and narrative fragments in the domain of international politics and economics. We identify problems with the pilot system and outline extensions required to incorporate several crucial dimensions of narrative structure.


Commonsense from the Web: Relation Properties

AAAI Conferences

When general purpose software agents fail, it's often because they're brittle and need more background commonsense knowledge. In this paper we present relation properties as a valuable type of commonsense knowledge that can be automatically inferred at scale by reading the Web. People base many commonsense inferences on their knowledge of relation properties such as functionality, transitivity, and others. For example, all people know that bornIn(Year) satisfies the functionality property, meaning that each person can be born in exactly one year. Thus inferences like "Obama was born in 1961, so he was not born in 2008", which computers do not know, are obvious even to children. We demonstrate scalable heuristics for learning relation functionality from noisy Web text that outperform existing approaches to detecting functionality. The heuristics we use address Web NLP challenges that are also common to learning other relation properties, and can be easily transferred. Each relation property we learn for a Web-scale set of relations will enable computers to solve real tasks, and the data from learning many such properties will be a useful addition to general commonsense knowledge bases.


A Cognitive-Consistency Based Model of Population Wide Attitude Change

AAAI Conferences

Attitudes play a significant role in determining how individuals process information and behave. In this paper we have developed a new computational model of population wide attitude change that captures the social level: how individuals interact and communicate information, and the cognitive level: how attitudes and concept interact with each other. The model captures the cognitive aspect by representing each individuals as a parallel constraint satisfaction network. The dynamics of this model are explored through a simple attitude change experiment where we vary the social network and distribution of attitudes in a population.


How do Systems Manage Their Adaptive Capacity to Successfully Handle Disruptions? A Resilience Engineering Perspective

AAAI Conferences

A large body of research describes the importance of adaptability for systems to be resilient in the face of disruptions. However, adaptive processes can be fallible, either because systems fail to adapt in situations requiring new ways of functioning, or because the adaptations themselves produce undesired consequences. A central question is then: how can systems better manage their capacity to adapt to perturbations, and constitute intelligent adaptive systems? Based on studies conducted in different high-risk domains (healthcare, mission control, military operations, urban firefighting), we have identified three basic patterns of adaptive failures or traps: (1) decompensation – when a system exhausts its capacity to adapt as disturbances and challenges cascade; (2) working at cross-purposes – when sub-systems or roles exhibit behaviors that are locally adaptive but globally maladaptive; (3) getting stuck in outdated behaviors – when a system over-relies on past successes although conditions of operation change. The identification of such basic patterns then suggests ways in which a work organization, as an example of a complex adaptive system, needs to behave in order to see and avoid or recognize and escape the corresponding failures. The paper will present how expert practitioners exhibit such resilient behaviors in high-risk situations, and how adverse events can occur when systems fail to do so. We will also explore how various efforts in research related to complex adaptive systems provide fruitful directions to advance both the necessary theoretical work and the development of concrete solutions for improving systems’ resilience.


Agent Support for Policy-Driven Mission Planning Under Constraints

AAAI Conferences

Forming ad-hoc coalitions between military forces and humanitarian organizations is crucial in mission-critical scenarios. Very often coalition parties need to operate according to planning constraints and regulations, or policies. Therefore, they find themselves not only in need to consider their own goals, but also to support coalition partners to the extent allowed by such regulations. In time-stressed conditions, this is a challenging and cognition-intensive task. In this paper, we present intelligent agents that support human planners and ease their cognitive burden by detecting and giving advice about the violation of policies and constraints. Through a series of experiments conducted with human subjects, we compare and contrast the agents' performance on a number of metrics in three conditions: agent support, transparent policy enforcement, and neither support nor enforcement.


Social-Psychological Harmonic Oscillators in the Self-Regulation of Organizations and Systems: The Physics of Conservation of Information (COI)

AAAI Conferences

Using computational intelligence, our ultimate goal is to self-regulate systems composed of humans, machines and robots. Self-regulation is important for the control of mixed organizations and systems. An overview of self-regulation for organizations and systems, characterized by our solution of the tradeoffs between Fourier pairs of Gaussian distributions that affect decision-making differently, is provided. A mathematical outline of our solution and a sketch of future plans are provided.


Discourse Structure Effects on the Global Coherence of Texts

AAAI Conferences

Many theories of discourse structure rely on the idea that the segments comprising the discourse are linked through inferred relations such as causality and temporal contiguity. These theories suggest that the resulting discourse is represented hierarchically. Two experiments examine some of the implications of these hierarchical structures on the perceived coherence of texts. Experiment 1 shows that texts with more levels to their hierarchical structure are judged to be more coherent. Experiment 2 demonstrates that these effects are sensitive to the genre of the text. Specifically, narratives seem to be more affected by manipulation of the discourse structure than procedural texts.


Social Issues in the Understanding of Narrative

AAAI Conferences

This paper proposes a number of social issues that are essential in understanding any given story, and thus, that must be included in a comprehensive approach to computational modeling of narrative. It focuses on oral narratives, and on the social event of the telling of a story. For participants in the telling, the central social issue is the story’s evaluation or meaning: the point or moral of the story. Value or meaning is created relative to social membership, and so, to understand evaluation, it is not sufficient to understand a story solely as a bounded unit. Therefore, this paper examines the ways in which narrative meaning is negotiated between narrator and interlocutors. It demonstrates how a given story can take on different meanings for different audiences. The life course of a story is also proposed as relevant dimension for understanding. Ephemeral stories are distinguished from stories which have multiple tellings, both for the stories of individuals, and for stories which form part of the story stock of institutions. Storytelling rights are also considered: who within a group has the right to tell a particular story on a particular occasion. These issues are proposed as potential meta-data to be used in the analysis of stories. Finally, the paper indicates an area in which computational understanding of narrative, including these social issues, has potential for practical applications: as part of current commercial knowledge capture and archiving activities.


Estimating time-varying networks

arXiv.org Machine Learning

Stochastic networks are a plausible representation of the relational information among entities in dynamic systems such as living cells or social communities. While there is a rich literature in estimating a static or temporally invariant network from observation data, little has been done toward estimating time-varying networks from time series of entity attributes. In this paper we present two new machine learning methods for estimating time-varying networks, which both build on a temporally smoothed $l_1$-regularized logistic regression formalism that can be cast as a standard convex-optimization problem and solved efficiently using generic solvers scalable to large networks. We report promising results on recovering simulated time-varying networks. For real data sets, we reverse engineer the latent sequence of temporally rewiring political networks between Senators from the US Senate voting records and the latent evolving regulatory networks underlying 588 genes across the life cycle of Drosophila melanogaster from the microarray time course.