P3 Puckster Partial Automation

MOVES Institute Research ProjectAutomated placement of sonobuoys to maintain contact with tracks and reduce NCTE operator workload

Unified derivation of phase-field models for alloy solidification from a grand-potential functional

In the literature, two quite different phase-field formulations for the problem of alloy solidification can be found. In the first, the material in the diffuse interfaces is assumed to be in an intermediate state between solid and liquid, with a unique local composition. In the second, the interface is seen as a mixture of two phases that each retain their macroscopic properties, and a separate concentration field for each phase is introduced. It is shown here that both types of models can be obtained by the standard variational procedure if a grand-potential functional is used as a starting point instead of a free-energy functional. The dynamical variable is then the chemical potential instead of the composition. In this framework, a complete analogy with phase-field models for the solidification of a pure substance can be established. This analogy is then exploited to formulate quantitative phase-field models for alloys with arbitrary phase diagrams. The precision of the method is illustrated by numerical simulations with varying interface thickness.Comment: 36 pages, 1 figur

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

An Analytical Method for Assessing the Effectiveness of Human in the Loop Simulation Environments: A work in progress

This paper discusses the development of the Integrated Training Environment Assessment Methodology (ITEAM). ITEAM is proposed as a way to assess integrated human in the loop (HITL) simulation training environment effectiveness (i.e. to determine how well the simulation tools support the deliberate practice of specific skills) at the human ability level. A work in progress, ITEAM has been used to reassess two previously evaluated military simulation environments -- the game Full Spectrum Command (2004) and the Engagement Skills Trainer Heavy Weapons Variant (2008). ITEAM results from both studies closely resemble and often match those concluded in the original empirical training effectiveness analysis (TEA) studies. A third study is currently underway to solidify ITEAM validity

Dynamics of gas bubble growth in a supersaturated solution with Sievert's solubility law

This paper presents a theoretical description of diffusion growth of a gas bubble after its nucleation in supersaturated liquid solution. We study systems where gas molecules completely dissociate in the solvent into two parts, thus making Sievert's solubility law valid. We show that the difference between Henry's and Sievert's laws for chemical equilibrium conditions causes the difference in bubble growth dynamics. Assuming that diffusion flux is steady we obtain a differential equation on bubble radius. Bubble dynamics equation is solved analytically for the case of homogeneous nucleation of a bubble, which takes place at a significant pressure drop. We also obtain conditions of diffusion flux steadiness. The fulfillment of these conditions is studied for the case of nucleation of water vapor bubbles in magmatic melts.Comment: 22 pages, 3 figure

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

Strategi Pengembangan Kawasan Wisata Danau Linouw di Kota Tomohon Provinsi Sulawesi Utara

North Sulawesi in addition to having some of the leading tourist attractions such as Bunaken Marine Park also has the attraction of alternative that still needs to be developed attractions include Lake Linouw in Tomohon. The purpose of this study was to identify appropriate development strategies in the tourist area of Lake Linouw in Tomohon, North Sulawesi. Research method was descriptive methods. Determination of the sample is based on non-probability sampling techniques. Collecting data through pre-survey, survey questionnaires, and study the literature. Data analysis has used SWOT analysis. The results showed that the tourist area of Linouw Lake at Tomohon, North Sulawesi is the growth strategies of concentration through vertical integration or the strategy of Rapid Growth Strategy (strategy of rapid growth). Therefore, it can be concluded that the main strategy to develop the tourist area of Lake Linouw be competitive position is strong and has a high tourist pull. Based on these research results, it is suggested that relevant parties should maintain tourist area Linouw Lake at Tomohon in a competitive position in the strong growth to improve tourist pull high and considering the relatively expensive tourist prices