Towards Learned Anticipation in Complex Stochastic Environments

We describe a novel methodology by which a software agent can learn to predict future events in complex stochastic environmentals. It is particularly relevant to environments that are construed specifically so as to be able to support high-performance software agents, such as video games. We present results gathered from a first prototype of our approach. The technique presented may have applications that range beyond improving agent performance, in particular to user modeling in the service of automated game testing

Utilizing Biological Models to Determine the Recruitment of the Irish Republican Army

Sociological models (e.g., social network analysis, small-group dynamics and gang models) have historically been used to predict the behavior of terrorist groups. However, they may not be the most appropriate method for understanding the behavior of terrorist organizations because the models were not initially intended to incorporate violent behavior of its subjects. Rather, models that incorporate life and death competition between subjects, i.e., models utilized by scientists to examine the behavior of wildlife populations, may provide a more accurate analysis. This paper suggests the use of biological models to attain a more robust method for understanding the behavior of terrorist organizations as compared to traditional methods. This paper also describes how a biological population model incorporating predator-prey behavior factors can predict terrorist organizational recruitment behavior for the purpose of understanding the factors that govern the growth and decline of terrorist organizations. The Lotka-Volterra, a biolgical model that is based on a predator-prey relationship, is applied to a highly suggestive case study, that of the Irish Republican Army. This case study illuminates how a biological model can be utilized to understand the actions of a terrorist organization

A Reference Model of Soldier Attention and Behavior

Proceedings of Behavior Representation in Modeling and Simulation (BRIMS) 2008.pdfThis research expands entity level representation of situation awareness and behavior. Building on previous work, the researchers developed an integrated and tractable modeling framework for the representation of a soldier's visual attention, situational awareness, and target acqusition ptior to a close range encounter, as well as the soldier's initial action choice. The researchers developed data to populate the model through subject matter expert questionnaires and a live virtual experiment. The resulting algorithms provide insight into soldier action of choice on contact. These and other aspects of the model have been coded for demonstration as a proof of principle, while work on the full reference model continues

Threat Density Map Modeling for Combat Simulations

The modeling and simulation community has used probability threat maps and other similar approaches to address search problems and improve decision-making. Probability threat maps describe the probability of a location containing one or more enemy entities at a particular time. Although useful, they only describe the likelihood that the location is occupied without addressing the degree to which it is occupied. Thus, we investigate whether threat density maps that describe the searcher’s expectation of seeing a number of target agents at a certain location in a given time interval are a viable method for improving synthetic behaviors in combat simulations. As a proof of principle, this paper introduces a probability model which quantifies the searcher agent’s subjective belief about the number of enemy entities in a location, given the initial information described by a prior density function and the information provided by the assumed sensing model. In addition, this paper discusses a framework for initializing the model, as well as the model’s key advantages and current limitations

Study of the total and partial fragmentation dynamics of Ar-HCl after UV photodissociation

The uv photolysis of the Ar–HCl cluster is studied applying an exact time-dependent wave packet method in three dimensions, assuming zero-total angular momentum. The photodissociation process is found to occur via two different fragmentation mechanisms, depending on the initial excitation energy of the cluster. One mechanism leads to total dissociation of the complex, producing three fragments, Ar–HCl+hν→H+Ar+Cl. The fragmentation dynamics in this case is governed by resonance states at relatively low energies of the cluster, in which the H atom collides a number of times with Ar and Cl before dissociating. Manifestations of these collisions are found in the final kinetic energy distribution of the photofragments, which is redshifted in the case of the H fragment, and blueshifted in the Ar and Cl cases. The second type of mechanism consists of a fast and direct photodissociation of the hydrogen, leading to a partial fragmentation of Ar–HCl into hot H fragments and bound Ar–Cl radical molecules. This mechanism dominates at higher energies, which are those mostly populated by the wave packet initially prepared in the present calculations. The experimental implications of the results are discussed. . © 1998 American Institute of Physics.This work was supported by D.G.I.C.Y.T., Spain, Grant No. PB95-0071.Peer Reviewe

Implementation of Monte Carlo Tree Search (MCTS) Algorithm in COMBATXXI using JDAFS

The implementation of the Monte Carlo Tree Search (MCTS) algorithm into the Combined Arms Analysis Tool for the 21st Century (COMBATXXI) project is an extension of work completed in FY13. The TRADOC Analysis Center - Methods and Research Office (TRAC-MRO) sponsored this iteration in an attempt to test the feasibility implementing the algorithm into the COMBATXXI simulation environment. For further details on the specific algorithm of more background information see appendix and the previous technical report.TRAC-MROTRAC Project Code # 060025Approved for public release; distribution is unlimited

Direct Observation of Martensitic Phase-Transformation Dynamics in Iron by 4D Single-Pulse Electron Microscopy

The in situ martensitic phase transformation of iron, a complex solid-state transition involving collective atomic displacement and interface movement, is studied in real time by means of four-dimensional (4D) electron microscopy. The iron nanofilm specimen is heated at a maximum rate of ∼10^(11) K/s by a single heating pulse, and the evolution of the phase transformation from body-centered cubic to face-centered cubic crystal structure is followed by means of single-pulse, selected-area diffraction and real-space imaging. Two distinct components are revealed in the evolution of the crystal structure. The first, on the nanosecond time scale, is a direct martensitic transformation, which proceeds in regions heated into the temperature range of stability of the fcc phase, 1185−1667 K. The second, on the microsecond time scale, represents an indirect process for the hottest central zone of laser heating, where the temperature is initially above 1667 K and cooling is the rate-determining step. The mechanism of the direct transformation involves two steps, that of (barrier-crossing) nucleation on the reported nanosecond time scale, followed by a rapid grain growth typically in ∼100 ps for 10 nm crystallites

C. elegans VANG-1 Modulates Life Span via Insulin/IGF-1-Like Signaling

The planar cell polarity (PCP) pathway is highly conserved from Drosophila to humans and a PCP-like pathway has recently been described in the nematode Caenorhabditis elegans. The developmental function of this pathway is to coordinate the orientation of cells or structures within the plane of an epithelium or to organize cell-cell intercalation required for correct morphogenesis. Here, we describe a novel role of VANG-1, the only C. elegans ortholog of the conserved PCP component Strabismus/Van Gogh. We show that two alleles of vang-1 and depletion of the protein by RNAi cause an increase of mean life span up to 40%. Consistent with the longevity phenotype vang-1 animals also show enhanced resistance to thermal- and oxidative stress and decreased lipofuscin accumulation. In addition, vang-1 mutants show defects like reduced brood size, decreased ovulation rate and prolonged reproductive span, which are also related to gerontogenes. The germline, but not the intestine or neurons, seems to be the primary site of vang-1 function. Life span extension in vang-1 mutants depends on the insulin/IGF-1-like receptor DAF-2 and DAF-16/FoxO transcription factor. RNAi against the phase II detoxification transcription factor SKN-1/Nrf2 also reduced vang-1 life span that might be explained by gradual inhibition of insulin/IGF-1-like signaling in vang-1. This is the first time that a key player of the PCP pathway is shown to be involved in the insulin/IGF-1-like signaling dependent modulation of life span in C. elegans

Level Annotation and Test by Autonomous Exploration

This paper proposes the use of an autonomous exploring agent to generate and annotate the waypoint graph as an offline process during level development. The explorer incrementally generates the waypoint graph as it explores the level via the same motion model used for palyer movement, and then revisits the waypoints to annotate them usimg image-based techniques. Points where the explorer becomes stuck or falls off of the level are flagged for later investigation by a level designer

Blended Inverse Kinematics: Delta3D System Utilization

Traditional inverse kinematics systems are riddled with issues that make their use in real-time simulations prohibitive. Foremost, the computational costs associated with these methods are too high to make their widespread use practical. Furthermore, the usage typically results in the synthesis of animations that fail to impart the sense of weight and timing that would be present in either motion captured or artist created forward kinematic animation. This is a byproduct of using a mathematical technique to solve an artistic problem. A new method we have developed succeeds in overcoming these shortcomings. By using a database of predefined animation poses, a new animation can be derived to achieve the desired pose. At it simplest, the technique can be used to maunally control a character's gaze for eimulating environmental awareness as well as directing a character's gun to point in the desired direction for aiming or shooting. it does all of this and more without burdening the CPU and can be easily enhanced using hardware skinning for optimal performance