Non-Uniform Chaotic Dynamics with Implications to Information Processing

1983 ◽  
Vol 38 (11) ◽  
pp. 1157-1169 ◽  
Author(s):  
J. S. Nicolis ◽  
G. Meyer-Kress ◽  
G. Haubs
Keyword(s):  
Information Processing ◽  
Characteristic Exponent ◽  
Quantitative Measure ◽  
External Noise ◽  
Strange Attractors ◽  
Pattern Perception ◽  
Small Subset ◽  
Chaotic Flows ◽  
Lyapunov Characteristic Exponent ◽  
High Degree

We study a new parameter - the "Non-Uniformity Factor" (NUF) -, which we have introduced in [1]. by way of estimating and comparing the deviation from average behavior (expressed by such factors as the Lyapunov characteristic exponent(s) and the information dimension) in various strange attractors (discrete and chaotic flows). Our results show for certain values of the control parameters the inadequacy of the above averaging properties in representing what is actually going on - especially when the strange attractors are employed as dynamical models for information processing and pattern recognition. In such applications (like for example visual pattern perception or communication via a burst-error channel) the high degree of adherence of the processor to a rather small subset of crucial features of the pattern under investigation or the flow, has been documented experimentally: Hence the weakness of concepts such as the entropy in giving in such cases a quantitative measure of the information transaction between the pattern and the processor. We finally investigate the influence of external noise in modifying the NUF

State Predictability and Information Flow in Simple Chaotic Systems

1986 ◽  
Vol 41 (6) ◽  
pp. 801-818 ◽  
Author(s):  
B. Pompe ◽  
J. Kruscha ◽  
R. W. Leven
Keyword(s):  
Information Flow ◽  
Chaotic Dynamics ◽  
Chaotic Systems ◽  
Characteristic Exponent ◽  
Intrinsic Noise ◽  
External Noise ◽  
Measuring Process ◽  
Lyapunov Characteristic Exponent ◽  
Space Partition ◽  
Future State

The possibility of state prediction in deterministic chaotic systems, which are described by 1-D maps, is discussed in the light o f information theory. A quantity h(l) is defined which represents the production of uncertainty on a future state by the chaotic dynamics (intrinsic noise) after / time steps have passed. h(l) is related to the Lyapunov characteristic exponent. Moreover, the influence of the measuring process (overlappings o f mapped boxes o f state space partition) and external noise on the state predictability are investigated quantitatively.

Variable assimilation of English word-final /n/: electropalatographic evidence

2020 ◽  
pp. 1-32
Author(s):  
ALEXEI KOCHETOV ◽  
LAURA COLANTONI ◽  
JEFFREY STEELE
Keyword(s):  
Present Article ◽  
English Word ◽  
Point Of View ◽  
Small Subset ◽  
Limited Extent ◽  
Canadian English ◽  
Place Assimilation ◽  
High Degree ◽  
Phonetic Realization

The phonetic realization of the English word-final alveolar nasal /n/ is known to be highly variable. Previous articulatory work has reported both gradient and categorical nasal place assimilation including considerable between-speaker differences. This work, however, has largely focused on a small subset of place contexts (namely, preceding velar /k, ɡ/) in a limited number of English varieties. The present article uses electropalatography to study the articulatory realization of /n/ in a wider range of phonetic contexts and read texts as produced by three speakers of Canadian English. The results reveal considerable inter- and intra-speaker differences in the rates of assimilation. Consistent with previous work, we observed a high degree of variation, both gradient and categorical, before velars. Substantial rates of assimilation were also observed before labials, where the process is unexpected from the point of view of gestural phonology but predicted by traditional phonological analyses. The variation in the place and stricture of /n/ before coronals was more limited and typically gradient. Finally, some differences were observed across the text conditions, with more assimilation occurring in carrier sentences than in the read passage and, to a more limited extent, in function than in content words.

Low-Temperature Set as a Measure of State of Vulcanization

1940 ◽  
Vol 13 (2) ◽  
pp. 222-234
Author(s):  
J. H. Fielding
Keyword(s):  
Low Temperature ◽  
Fundamental Property ◽  
Quantitative Measure ◽  
New Product ◽  
Temperature Behavior ◽  
Vulcanized Rubber ◽  
Scientific Equipment ◽  
Artificial Heat ◽  
Water Proof ◽  
High Degree

Abstract In his various patents on vulcanization, Charles Goodyear made several references to the change produced in the low-temperature behavior of rubber. In his earliest patent he stated that vulcanized rubber would not be “injuriously affected by exposure to cold”. The reissues of this patent stated the problem more clearly. “The leading object of my exertions was to render india-rubber capable of resisting the action of heat and cold within the range of atmospheric temperatures…. When compounded with sulfur, by the application of a high degree of artificial heat, I obtained good results, and when compounded with sulfur and the carbonate of lead I obtained the best results.”…. The new product “is water-proof, permanently and highly elastic under all conditions of its use”. Whether Goodyear was referring to the freezing of rubber under tension or under no tension we do not know, but it is probable that he had experienced both effects without distinguishing between them. It is interesting to find now that, one hundred years later, rubber chemists are still looking at this change in low-temperature behavior which he recognized as an effect of vulcanization, and are using the effect as a measure of degree of vulcanization. In recent years the T-50 test has gained considerable popularity as a quantitative measure of the tendency of rubber to freeze under tension. Its popularity is justified, since it can be applied over a broad range of cure and since it measures very precisely a seemingly fundamental property of rubber. It is, however, not the only means of expressing this effect quantitatively. The purpose of the present paper is to demonstrate a simpler method which yields surprisingly precise results, in spite of the fact that none of the usual scientific equipment is used and no measurements other than length measurements are required. Although other papers have approached this subject, none has as yet offered a simple substitute for T-50.

NONLINEAR DYNAMICS AND CHAOS PART I: A GEOMETRICAL APPROACH

1998 ◽  
Vol 2 (4) ◽  
pp. 505-532 ◽  
Author(s):  
Alfredo Medio
Keyword(s):  
Nonlinear Dynamics ◽  
Dynamical Systems ◽  
Characteristic Exponent ◽  
Chaotic Attractors ◽  
Modern Theory ◽  
Geometrical Approach ◽  
Lyapunov Characteristic Exponent ◽  
Geometrical Properties ◽  
Nonlinear Dynamics And Chaos ◽  
Different Types

This paper is the first part of a two-part survey reviewing some basic concepts and methods of the modern theory of dynamical systems. The survey is introduced by a preliminary discussion of the relevance of nonlinear dynamics and chaos for economics. We then discuss the dynamic behavior of nonlinear systems of difference and differential equations such as those commonly employed in the analysis of economically motivated models. Part I of the survey focuses on the geometrical properties of orbits. In particular, we discuss the notion of attractor and the different types of attractors generated by discrete- and continuous-time dynamical systems, such as fixed and periodic points, limit cycles, quasiperiodic and chaotic attractors. The notions of (noninteger) fractal dimension and Lyapunov characteristic exponent also are explained, as well as the main routes to chaos.

scholarly journals Information Gain in Event Space Reflects Chance and Necessity Components of an Event

Information ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 358 ◽  
Author(s):  
Georg F. Weber
Keyword(s):  
Phase Space ◽  
Ergodic Theorem ◽  
Information Gain ◽  
Characteristic Exponent ◽  
Vector Spaces ◽  
Event Space ◽  
Lyapunov Characteristic Exponent ◽  
Multiplicative Ergodic Theorem ◽  
Non Linear Systems ◽  
Eigenvectors And Eigenvalues

Information flow for occurrences in phase space can be assessed through the application of the Lyapunov characteristic exponent (multiplicative ergodic theorem), which is positive for non-linear systems that act as information sources and is negative for events that constitute information sinks. Attempts to unify the reversible descriptions of dynamics with the irreversible descriptions of thermodynamics have replaced phase space models with event space models. The introduction of operators for time and entropy in lieu of traditional trajectories has consequently limited—to eigenvectors and eigenvalues—the extent of knowable details about systems governed by such depictions. In this setting, a modified Lyapunov characteristic exponent for vector spaces can be used as a descriptor for the evolution of information, which is reflective of the associated extent of undetermined features. This novel application of the multiplicative ergodic theorem leads directly to the formulation of a dimension that is a measure for the information gain attributable to the occurrence. Thus, it provides a readout for the magnitudes of chance and necessity that contribute to an event. Related algorithms express a unification of information content, degree of randomness, and complexity (fractal dimension) in event space.

The impact of executive job demands on dismissals of newly appointed CEOs

2015 ◽  
Vol 21 (6) ◽  
pp. 705-724
Author(s):  
Yu-Kai M Wang ◽  
Kun M Yang
Keyword(s):  
Information Processing ◽  
Job Demands ◽  
International Diversification ◽  
Product Diversification ◽  
Explanatory Variables ◽  
Processing Theory ◽  
Ceo Dismissal ◽  
Diversified Firms ◽  
High Degree ◽  
The Impact

AbstractWhy are some newly appointed CEOs dismissed from their positions while others are not? Is it hard for newly appointed CEOs to survive in highly diversified firms? Drawing upon the concepts of executive job demands and information-processing theory, we argue that newly appointed CEOs face entirely different degrees of complexity and challenges in their role, and that firms’ product diversification and international diversification predict dismissals of newly appointed CEOs after controlling for other possible explanatory variables. Additionally, we propose that appointment of a new outsider CEO makes newly appointed CEOs more vulnerable to dismissal and consequently strengthens the predicted relationships. The empirical results support our arguments. These results suggest that the demands faced by a high degree of (product or international) diversification are likely to present challenges that increase the likelihood of corporate disruption through the departures of newly appointed CEOs. Contributions to the CEO dismissal and succession literature are discussed.

Loudness as a Cue for Acceptable Noise Levels

2014 ◽  
Vol 25 (06) ◽  
pp. 605-623 ◽  
Author(s):  
Karrie L. Recker ◽  
Martin F. McKinney ◽  
Brent W. Edwards
Keyword(s):  
Hearing Aids ◽  
Noise Level ◽  
Background Noise ◽  
Hearing Aid ◽  
Matching Task ◽  
Small Subset ◽  
Acceptable Noise Level ◽  
Matched Data ◽  
High Degree ◽  
Different Levels

Background/Purpose: The acceptable noise level (ANL) test is the only test that is known to predict success with hearing aids with a high degree of accuracy. A person’s ANL is the maximal amount of background noise that he or she is “willing to put up with” while listening to running speech. It is defined as the speech level minus the noise level, in decibels (dB). People who are willing to put up with high levels of background noise are generally successful hearing-aid wearers, whereas people who are not willing to put up with high levels of background noise are generally unsuccessful hearing-aid wearers. If it were known what cues that listeners are using to decide how much background noise they are willing to tolerate, then it might be possible to create technology that reduces these cues and improves listeners’ chances of success with hearing aids. As a first step toward this goal, this study investigated whether listeners are using loudness as a cue to determine their ANLs. Research Design and Study Sample: Twenty-one individuals with normal hearing and 21 individuals with sensorineural hearing loss participated in this study. In each group of 21 participants, 7 had a low ANL (<7 dB), 7 had a mid ANL (7–13 dB), and 7 had a high ANL (>13 dB). Data Collection/Analysis: Participants performed a modified version of the ANL in which the speech was fixed at four different levels (50, 63, 75 and 88 dBA), and participants adjusted the background noise (multitalker babble) to the maximal level at which they were willing to listen while following the speech. These results were compared with participants’ equal-loudness contours for the multitalker babble in the presence of speech. Equal-loudness contours were measured by having the participants perform a loudness-matching task in which they matched the level of the background noise (multitalker babble), played concurrently with speech, to a reference condition (also multitalker babble). During the test condition, the speech played at 50, 63, 75, or 88 dBA. All testing was performed in a sound booth with the speech and the noise presented from a loudspeaker at a 0° azimuth, 3 feet in front of the participant. Each condition was presented multiple times, and the results were averaged. Presentation order was randomized. Participants were tested unaided. Results: Participants' ANLs were compared with their equal-loudness contours for the background noise. ANLs that ran parallel to the equal-loudness contours were considered consistent with a loudness-based listening strategy. This pattern was observed for only two participants – both hearing-impaired. Conclusions: The majority of listeners showed no consistent trend between their ANLs and their loudness-matched data, suggesting that they are using cues other than loudness to determine their ANLs. ANLs were consistent with loudness-matched data for a small subset of listeners, suggesting that they may be using loudness as a cue for determining their ANLs.

scholarly journals Systematic and Random Sources of Variability in Perceptual Decision-Making: Comment on Ratcliff, Voskuilen, and McKoon (2018)

2019 ◽  
Author(s):  
Nathan J. Evans ◽  
Gabriel Tillman ◽  
Eric-Jan Wagenmakers
Keyword(s):  
Information Processing ◽  
External Noise ◽  
Cognitive Models ◽  
Human Cognition ◽  
Future Research ◽  
Perceptual Decision Making ◽  
Choice Decision ◽  
Random Variability ◽  
General Existence ◽  
Item Effects

A key assumption of models of human cognition is that there is variability in information processing. Evidence accumulation models (EAMs) commonly assume two broad variabilities in information processing: within-trial variability, which is thought to reflect moment-to-moment fluctuations in perceptual processes, and between-trial variability, which is thought to reflect variability in slower-changing processes like attention, or systematic variability between the stimuli on different trials. Recently, Ratcliff, Voskuilen, and McKoon (2018) claimed to “provide direct evidence that external noise is, in fact, required to explain the data from five simple two-choice decision tasks” (p. 33), suggesting that at least some portion of the between-trial variability in information processing is due to “noise”. However, we argue that Ratcliff et al. (2018) failed to distinguish between two different potential sources of between-trial variability: random (i.e., “external noise”) and systematic (e.g., item effects). Contrary to the claims of Ratcliff et al. (2018), we show that “external noise” is not required to explain their findings, as the same trends of data can be produced when only item effects are present. Furthermore, we contend that the concept of “noise” within cognitive models merely serves as a convenience parameter for sources of variability that we know exist, but are unable to account for. Therefore, we question the usefulness of experiments aimed at testing the general existence of “random” variability, and instead suggest that future research should attempt to replace the random variability terms within cognitive models with actual explanations of the process.

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