CHARACTERIZATION OF CHAOTICITY IN THE TRANSIENT CURRENT THROUGH PMMA THIN FILMS

Chaotic behavior in the transient current through thin Aluminum-PMMA-Aluminum films has been analyzed for times ranging up to 30,000s, in the temperature range 293–363K for applied voltages in the range 10–80V. Time series analysis reveals a positive Lyapunov exponent consistently and reproducibly throughout this range. Power law relaxation as reflected by the autocorrelation function and the positive Lyapunov exponent show parallel behaviors as a function of applied electric field.

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THERMAL STRESS BEHAVIOR IN NANO-SIZE THIN ALUMINUM FILMS

International Journal of Modern Physics B ◽

10.1142/s0217979206041902 ◽

2006 ◽

Vol 20 (25n27) ◽

pp. 4691-4696 ◽

Cited By ~ 1

Author(s):

TAKAO HANABUSA ◽

KAZUYA KUSAKA ◽

SHOSO SHINGUBARA ◽

OSAMI SAKATA

Keyword(s):

Thin Films ◽

Thermal Stress ◽

Synchrotron Radiation ◽

Thermal Stresses ◽

In Situ Observation ◽

Aluminum Films ◽

Stress Behavior ◽

Thin Aluminum ◽

20 Nm ◽

Nano Size

In-situ observation of thermal stresses in thin films deposited on a silicon substrate was made by synchrotron radiation. Specimens prepared in this experiment were nano-size thin aluminum films with SiO 2 passivation. The thickness of the films was 10 nm, 20 nm and 50 nm. Synchrotron radiation revealed the diffraction intensities for these thin films and make possible to measure stresses in nano-size thin films. Residual stresses in the as-deposited state were tensile. Compressive stresses were developed in a heating cycle up to 300°C and tensile stresses were developed in a cooling cycle. The thermal stresses in the 50 nm film showed linear behavior in the first heating stage from room temperature to 250°C followed by no change in the stress at 300°C, however, linearly behaved in the second cycle. On the other hand, the thermal stresses in 20 nm and 10 nm films almost linearly behaved without any hysteresis in increasing and decreasing temperature cycles. The mechanism of thermal stress behavior in thin films can be explained by strengthening of the nano-size thin films due to inhibition of dislocation source and dislocation motion.

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The Dynamics of Philippine Foreign Exchange Rates (2013-2017): A Test for Chaos

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijiteek1413.0981119 ◽

2019 ◽

Vol 8 (11) ◽

pp. 486-489

Keyword(s):

Time Series ◽

Exchange Rate ◽

Lyapunov Exponent ◽

Exchange Rates ◽

Foreign Exchange ◽

Chaotic Behavior ◽

The Philippines ◽

Series Data ◽

Largest Lyapunov Exponent ◽

Foreign Exchange Rates

In most studies on dynamics of time series financial data, the absence of chaotic behavior is generally observed. However, this theory is not yet established in the dynamics of foreign exchange rates. Conflicting claims of presence and absence of chaos in foreign exchange rates open door for further investigation considering various deterministic factors. This work examines the dynamics of exchange rate of the Philippine Peso against selected foreign currencies. Time series data were collected for eight (8) of Philippine’s top trading partners as categorized according to economic condition. The data obtained with permission from the Central Bank of the Philippines covered the years 2013 to 2017. Data sets were plotted revealing non-linear movement of Philippine exchange rates against time. The foreign exchange rate time series obtained per currency were examined for chaotic behavior by computing the Largest Lyapunov Exponents (LLE). A positive Lyapunov exponent is an indication of sensitivity dependence, i.e, a chaotic dynamics; whereas, a negative Lyapunov exponent indicates otherwise. Computed LLE’s varied per currency but all were found to be negative. Therefore, using the Largest Lyapunov Exponent Test (LLE), analysis of the time series of Philippine foreign exchange rates shows little evidence of chaotic patterns.

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Texture Control in Thin Films Using Ion Bombardment

Textures and Microstructures ◽

10.1155/tsm.34.105 ◽

2000 ◽

Vol 34 (2-3) ◽

pp. 105-118

Author(s):

G. S. Was ◽

H. Ji ◽

Z. Ma

Keyword(s):

Thin Films ◽

Physical Vapor Deposition ◽

Ion Bombardment ◽

Preferential Growth ◽

Aluminum Films ◽

Ion Channeling ◽

Preferential Sputtering ◽

Thin Aluminum ◽

Out Of Plane ◽

The Difference

The development of texture in thin films under ion bombardment is believed to occur due to the preferential growth of the aligned grains in the film relative to the unaligned grains. The difference in growth rates between aligned and unaligned grains results in the development of texture with increasing thickness. Both out-of-plane (fiber) and in-plane texture can be controlled during ion bombardment. Experiments were performed to create a (110) out-of-plane texture in thin aluminum films and to create a (110) in-plane texture in niobium films. Results showed that the texture in both cases increases in strength with depth, and that for 500 nm Al films, the (110) texture was stronger than the thermodynamically-preferred (111) texture obtained by physical vapor deposition. Results confirm a texturing mechanism based on ion channeling and preferential sputtering.

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Identification of Nonlinear and Chaotic Behavior in Model-Scale Liquefied Natural Gas (LNG) Carrier Experimental Data

Volume 6: 5th International Conference on Multibody Systems, Nonlinear Dynamics, and Control, Parts A, B, and C ◽

10.1115/detc2005-84459 ◽

2005 ◽

Author(s):

Leigh S. McCue ◽

Armin W. Troesch

Keyword(s):

Experimental Data ◽

Experimental Study ◽

Time Series ◽

Lyapunov Exponent ◽

Chaotic Behavior ◽

Surrogate Data ◽

Liquefied Natural Gas ◽

Nonlinear Time Series Analysis ◽

Beam Seas ◽

Fluid Sloshing

This paper presents the results of an experimental study simulating the behavior of LNG carriers with partially filled tanks exposed to beam seas. Details of the experimental model and method of data collection are presented. Additionally, surrogate data testing is employed to demonstrate nonlinearity in vessel roll time series. Lastly, Lyapunov exponent calculations are performed to detect chaotic behavior resulting from nonlinear vessel motions coupled with the dynamics of fluid sloshing in on-board tanks. The nonlinear time series analysis programs contained in the TISEAN package [1] are used extensively throughout this work.

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Chaoticity analysis of the current through pure, hydrogenated and hydrophobically modified PEG-Si thin films under varying relative humidity

Open Physics ◽

10.2478/s11534-009-0034-8 ◽

2009 ◽

Vol 7 (3) ◽

Cited By ~ 1

Author(s):

Kaan Atak ◽

Ozgur Aybar ◽

Gokhan Şahin ◽

Avadis Hacınlıyan ◽

Yani Skarlatos

Keyword(s):

Thin Films ◽

Time Series ◽

Polyethylene Glycol ◽

Lyapunov Exponent ◽

Relative Humidity ◽

Time Series Analysis ◽

Maximal Lyapunov Exponent ◽

Series Analysis ◽

Hydrophobically Modified ◽

Irregular Behavior

AbstractPolyethylene Glycol has an irregular current characteristic under constant voltage and slowly varying relative humidity. The current through a thin film of Gamma-isocyanatopropyltriethoxysilane added Polyethylene glycol (PEG-Si), its hydrogenated and hydrophobically modified forms, as a function of increasing relative humidity at equal time steps is analyzed for chaoticity. We suggest that the irregular behavior of current through PEG-Si thin films as a function of increasing relative humidity could best be analyzed for chaoticity using both time series analysis and detrended uctuation analysis; the relative humidity is kept as a slowly varying parameter. The presence of more then one regime is suggested by the calculation of the maximal Lyapunov exponents. Furthermore, the maximal Lyapunov exponent in each of the regimes was positive, thus confirming the presence of low dimensional chaos. DFA also confirms the presence of at least two different regimes, in agreement with the behavior of the maximal Lyapunov exponent in the time series analysis. We also suggest that the irregular behavior of the current through PEG-Si can be reduced by hydrogenating and hydrophobically modifying PEG-Si and the improvement in stability can be confirmed by our study.

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A Novel Measure Inspired by Lyapunov Exponents for the Characterization of Dynamics in State-Transition Networks

Entropy ◽

10.3390/e23010103 ◽

2021 ◽

Vol 23 (1) ◽

pp. 103

Author(s):

Bulcsú Sándor ◽

Bence Schneider ◽

Zsolt I. Lázár ◽

Mária Ercsey-Ravasz

Keyword(s):

Time Series ◽

Lyapunov Exponent ◽

Dynamical Systems ◽

State Transition ◽

Transition Probabilities ◽

Coarse Graining ◽

Special Focus ◽

Entropy Of Transition ◽

Transition Networks

The combination of network sciences, nonlinear dynamics and time series analysis provides novel insights and analogies between the different approaches to complex systems. By combining the considerations behind the Lyapunov exponent of dynamical systems and the average entropy of transition probabilities for Markov chains, we introduce a network measure for characterizing the dynamics on state-transition networks with special focus on differentiating between chaotic and cyclic modes. One important property of this Lyapunov measure consists of its non-monotonous dependence on the cylicity of the dynamics. Motivated by providing proper use cases for studying the new measure, we also lay out a method for mapping time series to state transition networks by phase space coarse graining. Using both discrete time and continuous time dynamical systems the Lyapunov measure extracted from the corresponding state-transition networks exhibits similar behavior to that of the Lyapunov exponent. In addition, it demonstrates a strong sensitivity to boundary crisis suggesting applicability in predicting the collapse of chaos.

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Effect of parameter calculation in direct estimation of the Lyapunov exponent in short time series

Discrete Dynamics in Nature and Society ◽

10.1080/10260220290013507 ◽

2002 ◽

Vol 7 (1) ◽

pp. 41-52 ◽

Cited By ~ 7

Author(s):

A. M. López Jiménez ◽

C. Camacho Martínez Vara de Rey ◽

A. R. García Torres

Keyword(s):

Time Series ◽

Lyapunov Exponent ◽

Chaotic Systems ◽

Chaotic Behavior ◽

Logistic Map ◽

Direct Methods ◽

Short Time Series ◽

Direct Estimation ◽

Non Linear ◽

Short Time

The literature about non-linear dynamics offers a few recommendations, which sometimes are divergent, about the criteria to be used in order to select the optimal calculus parameters in the estimation of Lyapunov exponents by direct methods. These few recommendations are circumscribed to the analysis of chaotic systems. We have found no recommendation for the estimation ofλstarting from the time series of classic systems. The reason for this is the interest in distinguishing variability due to a chaotic behavior of determinist dynamic systems of variability caused by white noise or linear stochastic processes, and less in the identification of non-linear terms from the analysis of time series. In this study we have centered in the dependence of the Lyapunov exponent, obtained by means of direct estimation, of the initial distance and the time evolution. We have used generated series of chaotic systems and generated series of classic systems with varying complexity. To generate the series we have used the logistic map.

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Interface Effects on the Adhesion of Thin Aluminum Films

MRS Proceedings ◽

10.1557/proc-472-155 ◽

1997 ◽

Vol 472 ◽

Author(s):

J.A. Schneider ◽

S. Guthrie ◽

N.R. Moody

Keyword(s):

Thin Films ◽

Fracture Toughness ◽

Vapor Deposition ◽

Scratch Testing ◽

Aluminum Films ◽

Sapphire Substrates ◽

Thin Aluminum ◽

Scratch Tests ◽

Interface Effects

ABSTRACTDifferences in the adhesion and fracture toughness of aluminum films on sapphire due to the presence of controlled contaminants are being investigated. Adhesion is evaluated by use of nanoindentation and continuous scratch tests. A comparison was made of the properties of textured thin films of aluminum (178 to 1890 nm) that were vapor deposited onto (0001) oriented sapphire substrates. A very thin (1 nm) layer of carbon was deposited at the interface of selected samples prior to the vapor deposition of the aluminum. Spalling was observed during continuous scratch testing in specimens with carbon at the interface but not in specimens without carbon at the interface.

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