CCSR Technical Reports, 2005-08

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CCSR Technical Reports,
with Abstracts: 2005-08

Technical Reports, with Abstracts: 2006

V. Gintautas, A. Hübler, A Simple, Low-Cost, Data-Logging Pendulum Built from a Computer Mouse , Technical Report CCSR-06-1

Abstract: Homework problems and examples involving a pendulum are often a big part of introductory physics classes and laboratory courses. Typically experiments are limited to using photogates to measure the period of the pendulum. Commercial rotary motion sensors that allow students to collect real-time motion data for a pendulum exist, but often the cost is too great to provide each student in the class with such a sensor. In contrast, a new 2-button ball mouse can be purchased for under $5. Therefore we present a cheap, easy-to-build rotary sensor pendulum using the existing hardware in a computer mouse. Preprint
K. C. Phelps, A. Hübler Towards an understanding of membership in youth organizations: Sudden changes in the average participation due to the behavior of one individual , Technical Report CCSR-06-2

Abstract: Peer pressure can induce sudden unexpected changes in the behavior of a group. With agent based simulations we study impact of one individual on the behavior of a social network of people. We find that the individual with the largest benefit dominates the group behavior. If that individual happens to have a leadership role, the impact is particularly strong. The model suggests that even if the average benefits for the group changes slowly the average participation changes suddenly and with a delay. The delay is shorter if the network is subject to large unpredictable outside influences. Further we find that incentives which target leaders are more effective than unspecific incentives. We discuss applications of the model to the dynamics of membership in agricultural youth organization. Preprint

Technical Reports, with Abstracts: 2005

J. Jun, A. Hübler, Formation and Structure of Ramified Charge Transportation Networks in an Electromechanical System , Technical Report CCSR-05-1

Abtract: We present findings in an experiment where we obtain stationary ramified transportation networks in a macroscopic nonbiological system. Our purpose here is to introduce the phenomenology of the experiment. We describe the dynamical formation of the network which consists of three growth stages: (I) strand formation,(II) boundary formation, and (III) geometric expansion. We find that the system forms statistically robust network features, like the number of termini and the number of branch points. We also find that the networks are usually trees, meaning that they lack closed loops; indeed, we find that loops are unstable in the network. Finally, we find that the final topology of the network is sensitive to the initial conditions of the particles, in particular to its geometry. Preprint
A. Hübler, Predicting Complex Systems With a Holistic Approach , Technical Report CCSR-05-2

Abtract: Systems become complex if their throughput is increased beyond a certain threshold. To understand the emerging irregular patterns and dynamics, phenomenological descriptions of their behavior must be translated into computational algorithms. We illustrate that the emerging structures appear to be particularly simple if we draw the boundary of the system at a location where the inputs and outputs are controllable. Further we show that the boundary can trigger two types of pattern forming processes: one which starts at the largest scales of the system and creates structure at smaller and smaller scales, and one that starts on the smallest scales and produces structure on larger scales. Only if we use a holistic approach, by considering both the both the bottom-up and the top-down patter formation process can we understand the emerging patterns and dynamics. Preprint
M. Baym, A. Hübler, Self-Adjusting Dynamical Systems With Wavelet Filtered Feedback , Technical Report CCSR-05-3

Abtract: Certain dynamical systems, such as the shift map and the logistic map, have an edge of chaos in their parameter spaces. On one side of this edge, the dynamics is mostly chaotic, on the other it is periodic. We find that discrete-time dynamical systems with wavelet-filtered feedback from the dynamical variable to the parameters are attracted to narrow parameter range near the edge of chaos, the periodic boundary regime. We show that the migration from the chaotic regime to the periodic boundary regime can be attributed to a conserved quantity, and find that such adaptation to the edge of chaos is accompanied by a depopulation of the chaotic regime. We use this conserved quantity to determine the location of the periodic boundary regime and show that its size is proportional to the size of the feedback. Further, we compute the dynamics of the probability density for the parameter for a specific example. Preprint
C. Strelioff, A. Hübler, Medium Term Prediction of Chaos , Technical Report CCSR-05-4

Abtract: We study prediction of chaotic time series when a perfect model is available but the initial condition is measured with uncertainty. A common approach for predicting future data given these circumstances is to apply the model despite the uncertainty. In systems with fold dynamics, we find prediction is improved over this strategy by recognizing this behavior. A systematic study of the logistic map demonstrates prediction of the most likely trajectory can be extended three time steps. Finally, we discuss application of these ideas to the Rössler attractor. Preprint
P. Melby, N. Weber, A. Hübler, Dynamics of Self-Adjusting Systems with Noise , Technical Report CCSR-05-5

Abtract: We perform studies of several self-adjusting systems with noise. In our analytical and numerical studies, we find that the dynamics of the self-adjusting parameter can be accurately described with a rescaled diffusion equation. We find that adaptation to the edge of chaos, a feature previously ascribed to self-adjusting systems, is only a long-lived transient when noise is present in the system. In addition, using analytical, numerical, and experimental studies, we find that noise can cause chaotic outbreaks where the parameter reenters the chaotic regime and the system dynamics become chaotic. We find that these chaotic outbreaks have a power law distribution in length. Preprint
B. Chase, A. Hübler, Inverse Energy-Uncertainty for a Simple Information Engine , Technical Report CCSR-05-6

Abtract: We examine the relationship between uncertainty in initial conditions and subsequent energy gain for a simple information engine in the likeness of Maxwell's Demon. Our engine consists of two noninteracting idealized classical particles in a two-compartment box. Using information about the initial states of the particles and our uncertainty in those states, we desire to capture both particles to perform work. We find that in certain cases the energy extracted is inversely proportional to the initial uncertainty. We also examine propteries of a nonlinear container. We also note that the average energy over all initial condition cases is approximately the fraction of particles which we can predict long enough for the possibility of capture to occur. Preprint

CCSR Technical Reports, with Abstracts: 2005-08

Technical Reports, with Abstracts: 2006

Technical Reports, with Abstracts: 2005

CCSR Technical Reports,
with Abstracts: 2005-08