Industry
Modeling and Simulating Community Sentiments and Interactions at the Pacific Missile Range Facility
Zanbaka, Catherine (BAE Systems)
PMRFSim is a proof of concept geospatial social agent-based simulation capable of examining the interactions of 60,000+ agents over a simulated year within a few minutes. PMRFSim utilizes real world data from sources ranging from the U.S. Census Bureau, a regional sociologist, and base security. PMRFSim models two types of agents, normal and adverse agents. Adverse agents have harmful intent and goals to spread negative sentiment and acquire intelligence. All agents are endowed with demographic and geospatial attributes. Agents interact with each other and respond to events. PMRFSim allows an analyst to construct various what-if scenarios and generates numerous graphs that characterize the social landscape. This analysis is intended to aid public affairs officers understand the social landscape.
Timing the Delivery of Preterm Fetus: A Case Study Based on Computer Simulation
Yu, Tina Gwoing (Memorial University of Newfoundland) | Chiu, Tsung-Hong (Chang Gung Memorial Hospital) | Wijngaard, Jeroen van den (Academic Medical Center) | Hsieh, T' (Chang Gung Memorial Hospital) | sang-T' (Academic Medical Center) | ang (McLaren Regiional Hospital) | Weserhof, Berend E | Tseng, Enson
The propagation of blood flow along the fetoplacental arterial system has been hypothesized to have a compensatory response to placental anomalies that may result in fetal stress. When the placenta generates increased resistance, the umbilical artery blood flow would decrease and in the worst scenario become absent, which will lead to fetal asphyxia and hypoxia. To compensate for the decreased oxygen supply from maternal placenta, the fetal middle cerebral arteries would become dilated leading to an increased diastolic flow, hence more oxygen. This compensatory phase , however, only lasts for a certain period of time, after which the hypoxia may lead to fetal demise or long term irreversible organ damages. In high-risk pregnancies, Doppler ultrasound technology is commonly used to monitor the fetoplacental arterial blood flow to assess fetal well being. If the anomalies occur prior to the end of the 40-week of gestation, surgical or aggressive medical intervention might be necessary to save the fetal life. Timing this intervention, however, is complex due to the fine balancing act to minimize potential risks from prematurity and organ damage vs. rescuing a fetal life through cesarean section or aggressive medical treatment or natural delivery at the earliest possible gestational age. A reasonable goal is to allow the pregnancy to continue to the point just before fetal damage occurs. To achieve that goal, various testing criteria, e.g. venous Doppler and fetal heart rate, have been used to identify de-compensation. In this work, we conducted computer simulation of the fetoplacental arterial blood flow of a Systemic Lupus Erythematosus (SLE) pregnancy based on Doppler blood flow readings taken during the 10-day period prior to the delivery. The simulation suggests that timing the delivery based on either Doppler waveform readings or fetal heart rates give similar pregnancy outcome.
Self-Organized Coupling Dynamics and Phase Transitions in Bicycle Pelotons
Trenchard, Hugh (Independent Researcher)
A peloton is a group of cyclists whose individual and collective energy expenditures are reduced when cyclists ride behind others in zones of reduced air pressure; this effect is known in cycling as โdraftingโ. As an aggregate of biological agents (human), a peloton is a complex dynamical system from which patterns of collective behaviour emerge, including phases and transitions between phases, through which pelotons oscillate. Coupling of cyclistsโ energy expenditures when drafting is the basic peloton property from which self-organized collective behaviours emerge. Shown here are equations that model coupling behaviours. Environmental constraints are further parameters that affect peloton dynamics. Phases are defined by thresholds of aggregate energy expenditure; shown here are two different, but consistent, conceptual descriptions of these phase transitions. The first is an energetic model that describes phases in terms of individual, bi-coupled and globally-coupled energy output thresholds that define four observable changes in peloton behaviour. A second, economic model incorporates competition and cooperation dynamics: cooperation increases as power outputs and course constraints increase and population diminishes, and where competition and cooperation for resources results in peloton divisions into sub-pelotons whose average fitness levels are more closely homogeneous.
Data Theory, Discourse Mining and Thresholds
Sallach, David L. (Argonne National Laboratory) | Ozik, Jonathan (Argonne National Laboratory)
The availability of online documents coupled with emergent text mining methods has opened new research horizons. To achieve their potential, mining technologies need to be theoretically focused. We present data theory as a crucial component of text mining, and provide a substantive proto- theory from the synthesis of complex multigames, prototype concepts, and emotio-cognitive orientation fields. We discuss how the data theory presented informs the application of text mining to mining discourse(s) and how, in turn, this allows for modeling across contextual thresholds. Finally, the relationship between discourse mining, data theory, and thresholds is illustrated with an historical example, the events surrounding the 1992 civil war in Tajikistan.
Emergence of Ultra-Conserved Protein Domains and Amino Acid Repeats: Adaptation, Competition and Thresholds
Rorick, Mary M. (Yale University) | Wagner, Gunter P. (Yale University)
Some proteins, such as homeodomain transcription factors, contain highly conserved regions of sequence that cannot be attributed to the constrains imposed by any single function. It has recently been suggested that multiple conserved functional domains overlap and together explain the high conservation of these regions. However, because these highly conserved domains are part of much larger proteins, we are still left with the question why so many functional domains cluster together. Here we have modeled an evolutionary mechanism that can produce this kind of clustering. Due to adaptive competition between different protein functions for control over amino acid residue identity, conserved functional domains get displaced from regions undergoing adaptive evolution. At first they undergo a steady random walk within the sequence for an indefinite amount of time; however, a threshold is reached when two functional domains happen to come into contact, at which point there is a dramatic shift in the adaptive dynamics such that the domains rapidly converge, lengthen, and evolve overlap โ stabilizing at a fully overlapped state. We also studied the evolution of single amino acid tandem repeats (a.k.a. homopeptides), which are especially prevalent in transcription factors. Homopeptides that are encoded by nonhomogenous mixtures of synonymous codons cannot be explained by the neutral process of replication slippage. Our model provides two ways to explain the origin and maintenance of such repeats, and their over-representation in highly conserved proteins: competition between multiple functional domains for space within a sequence, or reuse of a sequence for many functions over time. Both processes depend on reaching certain critical thresholds, however they both deterministically cause the evolution of repeats once these thresholds are reached. Further, both of these processes are characteristic of multi-functional proteins such as homeodomain transcription factors. We conclude that our model can explain two widely recognized features of transcription factor proteins: conserved domains and a tendency to accumulate homopeptides.
The Rise of the Modern State: Gradual Reform or Punctuated Transition
Root, Hilton L. (George Mason University)
A state is not alive, yet it performs many of the central enjoys few bonds of kinship: and residence depends upon functions of life like replication and adaptation to new conditions occupational specialization rather than blood relations. A to balance social protection and opportunity. As a modern state can declare war on behalf of the entire collectivity, lifelike system the rise of the modern state raises four sets reserving the right to declare mandatory participation of fundamental questions about its evolutionary design. A and to contract the area of private vengeance. They proclaim first set concerns how it became a sustainable, autonomously a monopoly of force and of law, while requiring citizens to replicating system, capable of evolution. All non-state agglomerations forgo violence; vengeance is not the responsibility of the offended such as empires or chiefdoms eventually stagnate party. Almost any crime against one member is a because they are closed systems that break down over crime against the state. Subgroups seeking vengeance are time (Weber). A state is an open system that must able to viewed as threatening to the order of the state.
Predicting and Controlling System-Level Parameters of Multi-Agent Systems
Miner, Don (University of Maryland, Baltimore County) | desJardins, Marie (University of Maryland, Baltimore County)
Boid flocking is a system in which several individual agents follow three simple rules to generate swarm-level flocking behavior. To control this system, the user must adjust the agent program parameters, which indirectly modifies the flocking behavior. This is unintuitive because the properties of the flocking behavior are non-explicit in the agent program. In this paper, we discuss a domain-independent approach for detecting and controlling two emergent properties of boids: density and a qualitative threshold effect of swarming vs. flocking. Also, we discuss the possibility of applying this approach to detecting and controlling traffic jams in traffic simulations.
A Computational Analysis of the Synergistic Effect of Coagulation Inhibitors on the Generation of Thrombin
Menke, Nathan B. (Virginia Commonwealth University) | Ward, Kevin R. (Virginia Commonwealth University) | Kier, Lemont B. (Virginia Commonwealth University) | Cheng, Chao-Kun (Virginia Commonwealth University) | Umesh R. Desai, Umesh R (Virginia Commonwealth University)
The coagulation system (CS) is a complex, inter-connected biological system with major physiological and pathological roles. The CS may be viewed as a complex adaptive system, in which individual components are linked through multiple feedback and feedforward loops. The non-linear relationships between the numerous coagulation factors and the interplay among the elements of the CS render the study of this biology at a molecular and cellular level nearly impossible. We present an Agent Based Modeling and Simulation (ABMS) approach for simulating these complex interactions. Our ABMS approach utilizes a subset of 52 rules to define the interactions among 33 enzymes and factors of the CS. These rules simulate the interaction of each โagentโ, such as substrates, enzymes, and cofactors, on a two-dimensional grid of ~12,000 cells and ~300,000 agents. Our ABMS method successfully reproduces the initiation, propagation, and termination of thrombin formation due to the activation of the extrinsic pathway. Furthermore, the ABMS is able to demonstrate the emergence of a threshold effect for thrombin generation as a result of the synergistic effect of combining anticoagulant systems.
Linking Network Structure and Diffusion through Stochastic Dominance
Lamberson, P. J. (Massachusetts Institute of Technology)
Recent research identifies stochastic dominance as critical for understanding the relationship between network structure and diffusion. This paper introduces the concept of stochastic dominance, explains the theory linking stochastic dominance and diffusion, and applies this theory to a number of diffusion studies in the literature. The paper illustrates how the theory connects observations from different disciplines, and details when and how those observations can be generalized to broader classes of networks.
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.