scholarly journals Information-theoretic analysis of complex systems modeled by two dimensional pairwise Ising models

2021 ◽  
Author(s):  
Alexandre Levada
Keyword(s):  
Complex Systems ◽  
Dependence Structure ◽  
Information Theoretic ◽  
Structure Information ◽  
Asymmetric Pattern ◽  
Temperature Parameter ◽  
Emergence Of Complexity ◽  
Spatial Dependence Structure ◽  
Random Nature ◽  
Linear Interactions

Abstract Stochastic complex systems are composed by a large number of seemingly simple variables that exhibit non-linear interactions with each other, causing the emergence of complexity and non-deterministic dynamics in the edge between order and chaos. Hence, the evolution of these systems seems to be completely out of control, with unpredictable behaviors. In this paper, using information geometry as a mathematical approach to chaos and complexity, we investigate how information theory can be used to analyze the dynamics of pairwise Ising random fields along Markov Chain Monte Carlo simulations in which phase transitions are observed. Our experiments indicate that Fisher information regarding the inverse temperature parameter can bring important insights, since it signalizes changes in the global spatial dependence structure. Information-theoretic curves are built to show that, despite the random nature of the system, it is possible to identify an asymmetric pattern of evolution when the system moves towards different entropic states.

scholarly journals On the complexity of assimilation in urban communities

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Renita Murimi
Keyword(s):  
Complex Systems ◽  
Urban Communities ◽  
Human Experience ◽  
Urban Environments ◽  
Urban Systems ◽  
Sociological Perspective ◽  
Information Theoretic ◽  
Information Theoretic Measures ◽  
Urban Complex ◽  
The Relationship

AbstractCities are microcosms representing a diversity of human experience. The complexity of urban systems arises from this diversity, where the services that cities offer to their inhabitants have to be tailored for their unique requirements. This paper studies the complexity of urban environments in terms of the assimilation of its communities. We examine the urban assimilation complexity with respect to the foreignness between communities and formalize the level of complexity using information-theoretic measures. Our findings contribute to a sociological perspective of the relationship between urban complex systems and the diversity of communities that make up urban systems.

scholarly journals Spatial continuity of soil attributes in an Atlantic Forest remnant in the Mantiqueira Range, MG

2013 ◽  
Vol 37 (1) ◽  
pp. 68-77 ◽  
Author(s):  
Marcela de Castro Nunes Santos ◽  
José Marcio de Mello ◽  
Carlos Rogério de Mello ◽  
Léo Fernandes Ávila
Keyword(s):  
Atlantic Forest ◽  
Spatial Dependence ◽  
Soil Bulk Density ◽  
Exchange Capacity ◽  
Dependence Structure ◽  
Spatial Continuity ◽  
Soil Attributes ◽  
Forest Remnant ◽  
Spatial Dependence Structure

The spatial characterization of soil attributes is fundamental for the understanding of forest ecosystems. The objective of this work was to develop a geostatistical study of chemical and physical soil attributes at three depths (D1 - 0-20 cm; D2 - 20-50 cm; D3 - 50-100 cm), in an Experimental Hydrographic Micro-catchment entirely covered by Atlantic Forest, in the Mantiqueira Range region, Minas Gerais. All the considered variables presented spatial dependence structure in the three depths, and the largest degrees of spatial dependence were observed for pH in the three depths, soil cation exchange capacity potential in D3, soil organic matter in D1 and D3 and clay and soil bulk density in D2. The method most used for the adjustments of semi-variogram models was the Maximum Likelihood and the most selected model was the Exponential. Furthermore, the ordinary kriging maps allowed good visualization of the spatial distribution of the variables.

scholarly journals Direct and Indirect Effects—An Information Theoretic Perspective

Entropy ◽  
2020 ◽  
Vol 22 (8) ◽  
pp. 854 ◽  
Author(s):  
Gabriel Schamberg ◽  
William Chapman ◽  
Shang-Ping Xie ◽  
Todd P. Coleman
Keyword(s):  
Pacific Northwest ◽  
Southern Oscillation ◽  
Causal Effect ◽  
Climate Science ◽  
Causal Effects ◽  
Direct And Indirect Effects ◽  
General Applicability ◽  
Information Theoretic ◽  
The North ◽  
Linear Interactions

Information theoretic (IT) approaches to quantifying causal influences have experienced some popularity in the literature, in both theoretical and applied (e.g., neuroscience and climate science) domains. While these causal measures are desirable in that they are model agnostic and can capture non-linear interactions, they are fundamentally different from common statistical notions of causal influence in that they (1) compare distributions over the effect rather than values of the effect and (2) are defined with respect to random variables representing a cause rather than specific values of a cause. We here present IT measures of direct, indirect, and total causal effects. The proposed measures are unlike existing IT techniques in that they enable measuring causal effects that are defined with respect to specific values of a cause while still offering the flexibility and general applicability of IT techniques. We provide an identifiability result and demonstrate application of the proposed measures in estimating the causal effect of the El Niño–Southern Oscillation on temperature anomalies in the North American Pacific Northwest.

scholarly journals An Information-Theoretic Framework for Complex Systems

2018 ◽  
Vol 140 (12) ◽  
pp. S16-S23
Author(s):  
Hanieh Agharazi ◽  
Wanchat Theeranaew ◽  
Kolacinski Richard M. ◽  
Kenneth A. Lopaor
Keyword(s):  
Communication Network ◽  
Complex Systems ◽  
Information Channel ◽  
Information Theoretic

We propose an information-theoretic framework for modeling complex systems as a communication network where physical devices can be organized into subsystems and subsystems are communicating through an information channel governed by the dynamics of the system.

scholarly journals Variability and spatial correlation of soil micronutrients and organic matter with macadamia nut production

2020 ◽  
Vol 24 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Jaqueline O. Paris ◽  
Ivoney Gontijo ◽  
Fábio L. Partelli ◽  
Alexandro G. Facco
Keyword(s):  
Organic Matter ◽  
Spatial Correlation ◽  
Agricultural Production ◽  
Minimum Distance ◽  
Geostatistical Analysis ◽  
Dependence Structure ◽  
Macadamia Nut ◽  
Nut Production ◽  
Spatial Dependence Structure ◽  
Opposite Tendency

ABSTRACT Soil fertility is the key to agricultural production. The spatial correlation and location of nutrients may significantly affect the yields. The objective of this work was to evaluate the variability and spatial correlation of iron (Fe), copper (Cu), manganese (Mn), zinc (Zn), and organic matter (OM) with macadamia nut yield. The study was conducted in an Oxisol cultivated for 20 years with macadamia nut in São Mateus, state of Espírito Santo, Brazil. A 100 point grid was used comprising an area of 144 × 140 m with a minimum distance between points of 5 m, in which a single composite soil sample was collected from 0-0.20 m layer for chemical analysis of Fe, Cu, Mn, Zn and OM. Nuts under the canopy’s projection were harvested from February to June, 2015. The data were evaluated by geostatistical analysis using semivariograms, and kriging was used to map spatial distributions of nutrients and nut yield. All evaluated attributes showed strong or moderate spatial dependence structure. The OM was correlated positively with micronutrients, but only Zn was positively correlated with nut yield. Crossed semivariograms adequately explained the maps of Zn and Mn; and Fe showed opposite tendency for macadamia nut yield.

scholarly journals Spatial variability and sampling density of chemical attributes in archaeological black earths under pasture in southern Amazonas, Brazil

2019 ◽  
Author(s):  
Alan F. L. de Lima ◽  
Milton C. C. Campos ◽  
José M. da Cunha ◽  
Laércio S. Silva ◽  
Flávio P. de Oliveira ◽  
...  
Keyword(s):  
Spatial Variability ◽  
Spatial Dependence ◽  
Spatial Behavior ◽  
Dependence Structure ◽  
Sampling Efficiency ◽  
Sampling Density ◽  
Agricultural Planning ◽  
Chemical Attributes ◽  
Spatial Dependence Structure ◽  
Potential Acidity

Abstract. Spatial mapping of soil chemical attributes is essential for sampling efficiency and agricultural planning management, ensuring a regional development and sustainability of the unique characteristics of archaeological black earths (ABEs). Thus, this study was developed aiming at assessing the spatial variability and sampling density of chemical attributes in soils of ABEs under pasture in southern Amazonas, Brazil. A sampling grid of 56 × 80 m with regular spacings of 8 m was installed in the experimental area and samples were taken from the crossing points at depths of 0.0–0.05, 0.05–0.10, and 0.10–0.20 m, totaling 264 georeferenced points. The chemical attributes pH in water, organic carbon, Ca, Mg, K, P, Al, and potential acidity were determined in these samples, while CEC, SB, V, t, T, and m were calculated. The attributes present a spatial dependence varying from strong to moderate, being Al3+ the only chemical attribute that does not present a spatial dependence structure in the assessed depths. Scaled semivariograms satisfactorily reproduce the spatial behavior of attributes in the same pattern of individual semivariograms, allowing their use to estimate the variability of soil attributes. Sampling density is higher at a depth of 0.0–0.05 m, requiring 2 and 1 point ha−1 at depths of 0.05–0.10 and 0.10–0.20 m, respectively, to represent the spatial pattern of chemical attributes.

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