Government
Concepts from Data
Rohrer, Brandon (Sandia National Laboratories)
Creating new concepts from data is a hard problem in the development of cognitive architectures, but one that must be solved for the BICA community to declare success. Two concept generation algorithms are presented here that are appropriate to different levels of concept abstraction: state-space partitioning with decision trees and context-based similarity.
Applied Cognitive Models of Frequency-based Decision Making
Staszewski, Jim (Carnegie Mellon University)
In this paper, we present a cognitive model of frequency-based decision-making applied to the task of landmine detection. The model is implemented in the ACT-R cognitive architecture and is strongly constrained by the cognitive primitives of the architecture. We then generalize the model to another task in the domain of macroeconomic decision-making using the same architecture, pursuing theoretical parsimony. We describe each model's representation requirements, assess their fits to the data, and analyze their performance scaling as a function of task and architectural parameters. Efforts to generalize the landmine detection model to macroeconomic decision making showed that reasonable fits to the macro-economic performance data could be achieved by models based either on procedural knowledge or declarative knowledge. This finding underscores the importance of distinguishing between processing strategies employed to execute tasks. Such detail appears needed to understand the neural foundations of frequency-based decision-making.
Dynamic Threshold Modeling of Budget Changes
Jones, Bryan D. (University of Texas at Austin) | Zalanyi, Laszlo (Hungarian Academy of Sciences) | Baumgartner, Frank R. (University of North Carolina) | Erdi, Peter L. (Kalamazoo College)
Early studies of public budgeting emphasized uncertainty Two of us (BJ and FB) have published a set of papers, in the decision-making environment. Budgeting in the books focusing on annual budget changes (Jones and absence of information about the impacts of decisions led Baumgartner 2005b). Leptokurtic distribution of percentual to an adjustment process rooted in simple decision rules budget changes were observed in a broad range of settings: and bargaining among interests. This led to marginal or small increases and small decreases of budgets and budget incremental adjustments from the budgetary status quo, components are the most frequent, but time to time large with all major actors wary of big changes to the budgetary increases and cutoffs are observed as well.
Using Complex Adaptive Systems to Simulate Information Operations at the Department of Defense
Duong, Deborah Vakas (ACI Edge)
Irregular Warfare (IW), with its emphasis on social and cognitive phenomena such as population sentiment, is a major new focus of the Department of Defense (DoD). One of the most important classes of IW action is Information Operations (IO), the use of information to influence sentiment. With the DoD’s new focus on IW comes the new need to analyze and forecast the effects of IO actions on population sentiment. Analysts at the DoD traditionally use Modeling and Simulation to analyze and forecast the effects of conventional warfare’s actions on the outcome of wars, but IW and IO in particular are far more complex than conventional physics-based simulations. DoD analysts are in the early stages of looking for scientifically rigorous methods in the Modeling and Simulation of IO’s complex effects. This paper presents the state of IO modeling and simulation in the DoD, using examples from several computer models now being used, in these early stages of IW analysis. It discusses how the ideas of Complex Adaptive Systems (CAS) and threshold events in particular may be incorporated into IO modeling in order to increase its scientific rigor, fidelity, and validity.
Scenario Generation Using Double Scope Blending
Tan, Kian-Moh Terence (National University of Singapore) | Kwok, Kenneth (National University of Singapore)
Conceptual Blending through the process of Double Scope Blending provides an account for human creativity. We show how computational creativity can be modeled after Double Scope Blending for machine generation of scenarios, stories, hypotheses, etc. This paper describes an application of this process to the generation of novel and creative scenarios in the maritime security domain.
Hypertableau Reasoning for Description Logics
Motik, B., Shearer, R., Horrocks, I.
We present a novel reasoning calculus for the description logic SHOIQ^+---a knowledge representation formalism with applications in areas such as the Semantic Web. Unnecessary nondeterminism and the construction of large models are two primary sources of inefficiency in the tableau-based reasoning calculi used in state-of-the-art reasoners. In order to reduce nondeterminism, we base our calculus on hypertableau and hyperresolution calculi, which we extend with a blocking condition to ensure termination. In order to reduce the size of the constructed models, we introduce anywhere pairwise blocking. We also present an improved nominal introduction rule that ensures termination in the presence of nominals, inverse roles, and number restrictions---a combination of DL constructs that has proven notoriously difficult to handle. Our implementation shows significant performance improvements over state-of-the-art reasoners on several well-known ontologies.
Content Modeling Using Latent Permutations
Chen, H., Branavan, S.R.K., Barzilay, R., Karger, D. R.
We present a novel Bayesian topic model for learning discourse-level document structure. Our model leverages insights from discourse theory to constrain latent topic assignments in a way that reflects the underlying organization of document topics. We propose a global model in which both topic selection and ordering are biased to be similar across a collection of related documents. We show that this space of orderings can be effectively represented using a distribution over permutations called the Generalized Mallows Model. We apply our method to three complementary discourse-level tasks: cross-document alignment, document segmentation, and information ordering. Our experiments show that incorporating our permutation-based model in these applications yields substantial improvements in performance over previously proposed methods.
Dealing with incomplete agents' preferences and an uncertain agenda in group decision making via sequential majority voting
Pini, Maria, Rossi, Francesca, Venable, Brent, Walsh, Toby
We consider multi-agent systems where agents' preferences are aggregated via sequential majority voting: each decision is taken by performing a sequence of pairwise comparisons where each comparison is a weighted majority vote among the agents. Incompleteness in the agents' preferences is common in many real-life settings due to privacy issues or an ongoing elicitation process. In addition, there may be uncertainty about how the preferences are aggregated. For example, the agenda (a tree whose leaves are labelled with the decisions being compared) may not yet be known or fixed. We therefore study how to determine collectively optimal decisions (also called winners) when preferences may be incomplete, and when the agenda may be uncertain. We show that it is computationally easy to determine if a candidate decision always wins, or may win, whatever the agenda. On the other hand, it is computationally hard to know wheth er a candidate decision wins in at least one agenda for at least one completion of the agents' preferences. These results hold even if the agenda must be balanced so that each candidate decision faces the same number of majority votes. Such results are useful for reasoning about preference elicitation. They help understand the complexity of tasks such as determining if a decision can be taken collectively, as well as knowing if the winner can be manipulated by appropriately ordering the agenda.
Just-In-Time Scheduling with Constraint Programming
Monette, Jean-Noël (Université Catholique de Louvain) | Deville, Yves (Université catholique de Louvain) | Hentenryck, Pascal Van (Brown University)
This paper considers Just-In-Time Job-Shop Scheduling, in which each activity has an earliness and a tardiness cost with respect to a due date. It proposes a constraint programming approach, which includes a novel filtering algorithm and dedicated heuristics. The filtering algorithm uses a machine relaxation to produce a lower bound that can be obtained by solving a Just-In-Time Pert problem. It also includes pruning rules which update the variable bounds and detect precedence constraints. The paper presents experimental results which demonstrate the effectiveness of the approach over a wide range of benchmarks.
Automatic Derivation of Memoryless Policies and Finite-State Controllers Using Classical Planners
Bonet, Blai (Universidad Simón Bolívar) | Palacios, Héctor (Universidad Simón Bolívar) | Geffner, Héctor (ICREA and Universitat Pompeu Fabra)
Finite-state and memoryless controllers are simple action selection mechanisms widely used in domains such as video-games and mobile robotics. Memoryless controllers stand for functions that map observations into actions, while finite-state controllers generalize memoryless ones with a finite amount of memory. In contrast to the policies obtained from MDPs and POMDPs, finite-state controllers have two advantages: they are often extremely compact, involving a small number of controller states or none at all, and they are general, applying to many problems and not just one. A limitation of finite-state controllers is that they must be written by hand. In this work, we address this limitation, and develop a method for deriving finite-state controllers automatically from models. These models represent a class of contingent problems where actions are deterministic and some fluents are observable. The problem of deriving a controller from such models is converted into a conformant planning problem that is solved using classical planners, taking advantage of a complete translation introduced recently. The controllers derived in this way are 'general' in the sense that they do not solve the original problem only, but many variations as well, including changes in the size of the problem or in the uncertainty of the initial situation and action effects. Experiments illustrating the derivation of such controllers are presented.