scholarly journals Biodiversity, functional redundancy and system stability: subtle connections

2018 ◽  
Vol 15 (147) ◽  
pp. 20180367 ◽  
Author(s):  
Robert E. Ulanowicz
Keyword(s):  
Conditional Entropy ◽  
Functional Redundancy ◽  
System Stability ◽  
Biomass Distribution ◽  
Information Theoretic ◽  
Trophic Networks ◽  
System Components ◽  
Hill Numbers ◽  
Ensemble Systems ◽  
The Relationship

The relationship between biodiversity and functional redundancy has remained ambiguous for over a half-century, likely due to an inability to distinguish between positivist and apophatic (that which is missing) properties of ecosystems. Apophases are best addressed by mathematics that is predicated upon absence, such as information theory. More than 40 years ago, the conditional entropy of a flow network was proposed as a formulaic way to quantify trophic functional redundancy, an advance that has remained relatively unappreciated. When applied to a collection of 25 fully quantified trophic networks, this authoritative index correlates only poorly and transitively with conventional Hill numbers used to represent biodiversity. Despite such a weak connection, the underlying biomass distribution remains useful in conjunction with the qualitative diets of system components for providing a quick and satisfactory emulation of a system's functional redundancy. Furthermore, an information-theoretic cognate of the Wigner Semicircle Rule can be formulated using network conditional entropy to provide clues to the relative stability of any ecosystem under study. The necessity for a balance between positivist and apophatic attributes pertains to the functioning of a host of other living ensemble systems.

scholarly journals A Risk-Based Approach to Assess the Operational Resilience of Transmission Grids

2020 ◽  
Vol 10 (14) ◽  
pp. 4761
Author(s):  
Milorad Papic ◽  
Svetlana Ekisheva ◽  
Eduardo Cotilla-Sanchez
Keyword(s):  
Power System ◽  
North American ◽  
Response Times ◽  
Transmission System ◽  
Energy Delivery ◽  
The North ◽  
System Components ◽  
Bulk Power ◽  
Definition Of ◽  
The Relationship

Modern risk analysis studies of the power system increasingly rely on big datasets, either synthesized, simulated, or real utility data. Particularly in the transmission system, outage events have a strong influence on the reliability, resilience, and security of the overall energy delivery infrastructure. In this paper we analyze historical outage data for transmission system components and discuss the implications of nearby overlapping outages with respect to resilience of the power system. We carry out a risk-based assessment using North American Electric Reliability Corporation (NERC) Transmission Availability Data System (TADS) for the North American bulk power system (BPS). We found that the quantification of nearby unscheduled outage clusters would improve the response times for operators to readjust the system and provide better resilience still under the standard definition of N-1 security. Finally, we propose future steps to investigate the relationship between clusters of outages and their electrical proximity, in order to improve operator actions in the operation horizon.

scholarly journals Area Entropy and Quantized Mass of Black Holes from Information Theory

Entropy ◽  
2021 ◽  
Vol 23 (7) ◽  
pp. 858
Author(s):  
Dongshan He ◽  
Qingyu Cai
Keyword(s):  
Information Theory ◽  
Black Hole ◽  
Black Hole Entropy ◽  
Quantum Corrections ◽  
Compton Wavelength ◽  
Information Theoretic ◽  
Curved Space ◽  
Thermodynamic Entropy ◽  
Hole Area ◽  
The Relationship

In this paper, we present a derivation of the black hole area entropy with the relationship between entropy and information. The curved space of a black hole allows objects to be imaged in the same way as camera lenses. The maximal information that a black hole can gain is limited by both the Compton wavelength of the object and the diameter of the black hole. When an object falls into a black hole, its information disappears due to the no-hair theorem, and the entropy of the black hole increases correspondingly. The area entropy of a black hole can thus be obtained, which indicates that the Bekenstein–Hawking entropy is information entropy rather than thermodynamic entropy. The quantum corrections of black hole entropy are also obtained according to the limit of Compton wavelength of the captured particles, which makes the mass of a black hole naturally quantized. Our work provides an information-theoretic perspective for understanding the nature of black hole entropy.

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 Information Guided Exploration of Scalar Values and Isocontours in Ensemble Datasets

Entropy ◽  
2018 ◽  
Vol 20 (7) ◽  
pp. 540 ◽  
Author(s):  
Subhashis Hazarika ◽  
Ayan Biswas ◽  
Soumya Dutta ◽  
Han-Wei Shen
Keyword(s):  
Weather Forecasting ◽  
Conditional Entropy ◽  
Specific Information ◽  
Theoretic Approach ◽  
Information Theoretic ◽  
Information Measures ◽  
New Information ◽  
Real World Datasets ◽  
The Individual ◽  
Information Theoretic Approach

Uncertainty of scalar values in an ensemble dataset is often represented by the collection of their corresponding isocontours. Various techniques such as contour-boxplot, contour variability plot, glyphs and probabilistic marching-cubes have been proposed to analyze and visualize ensemble isocontours. All these techniques assume that a scalar value of interest is already known to the user. Not much work has been done in guiding users to select the scalar values for such uncertainty analysis. Moreover, analyzing and visualizing a large collection of ensemble isocontours for a selected scalar value has its own challenges. Interpreting the visualizations of such large collections of isocontours is also a difficult task. In this work, we propose a new information-theoretic approach towards addressing these issues. Using specific information measures that estimate the predictability and surprise of specific scalar values, we evaluate the overall uncertainty associated with all the scalar values in an ensemble system. This helps the scientist to understand the effects of uncertainty on different data features. To understand in finer details the contribution of individual members towards the uncertainty of the ensemble isocontours of a selected scalar value, we propose a conditional entropy based algorithm to quantify the individual contributions. This can help simplify analysis and visualization for systems with more members by identifying the members contributing the most towards overall uncertainty. We demonstrate the efficacy of our method by applying it on real-world datasets from material sciences, weather forecasting and ocean simulation experiments.

MODEL ODOR-ORIENTED PREDATORS AND PREY

2006 ◽  
Vol 17 (05) ◽  
pp. 711-720
Author(s):  
MINGFENG HE ◽  
PU LI ◽  
CHANGQUAN NI
Keyword(s):  
Monte Carlo ◽  
System Stability ◽  
System State ◽  
System States ◽  
The Relationship

The model of predators and prey, in which the predator judges the direction of prey's movement on the basis of the density of prey's odor will be researched in this article. The predator' s sensitivity to prey's odor is defined, so that can be simulated by Monte Carlo in L × L. It suggests the relationship between system stability and each value of Predator's sensitivity. We get three system states for different value of α (predator's sensitivity): the grass only, prey and the grass, three species in coexistence, with predators, prey and grass. But the probability of each system state is different. Their corresponding distribution will be given in this article.

Modeling and Stability Analysis of Dynamic Control Through a Soft Interface

2006 ◽  
Vol 18 (3) ◽  
pp. 242-248 ◽  
Author(s):  
Mizuho Shibata ◽  
◽  
Shinichi Hirai
Keyword(s):  
Stability Analysis ◽  
Discrete Time ◽  
Feedforward Control ◽  
Dynamic Control ◽  
System Stability ◽  
Critical Stability ◽  
Runge Kutta Method ◽  
The Stability ◽  
The Relationship ◽  
Soft Interface

To analyze the stability of dynamic control through asoft interface-the viscoelastic material between a manipulating finger and a manipulated object- we model dynamic control through the soft interface in continuous-discrete time. We then formulate dynamics using a modified z-transform in continuous-discrete time for feedback and feedforward control. We show that system stability depends on the viscoelasticity of the soft interface for feedback control. The relationship between material viscosity and sampling time in critical stability is not monotonous, a phenomenon we analyze by root locus. We compare stability analysis by the modified z-transform, simulations based on the Runge-Kutta method, and a regular z-transform, demonstrating that the relationship is specific to a continuous-discrete time.

The Information Theoretic Perspective on Context Aware Network Design

2012 ◽  
Vol 433-440 ◽  
pp. 5073-5077
Author(s):  
Jing Yao Wang ◽  
Meng Jia Li ◽  
Mei Song ◽  
Ying Hai Zhang
Keyword(s):  
Information Theory ◽  
Network Design ◽  
Information Entropy ◽  
Communication Systems ◽  
Network Performance ◽  
Theoretical Framework ◽  
Context Aware ◽  
Information Theoretic ◽  
The Future ◽  
The Relationship

Information theory has made great impact on the research of communication systems. However, analyze and design of networks has not benefited too much from information theory. Therefore, in this paper, we propose the information-theoretical framework of context aware network to explore the relationship between the information and the network performance. We also analyze the information traffic process in context aware network. To illustrate our approach, we analyze the architecture of context aware network by the information entropy produced in the network, and discuss the way to improve the performance of context aware in an information-theoretic perspective. The results in this paper may be also used to design other network and guide the future network design.

scholarly journals Lack of functional redundancy in the relationship between microbial diversity and ecosystem functioning

2016 ◽  
Vol 104 (4) ◽  
pp. 936-946 ◽  
Author(s):  
Manuel Delgado-Baquerizo ◽  
Luca Giaramida ◽  
Peter B. Reich ◽  
Amit N. Khachane ◽  
Kelly Hamonts ◽  
...  
Keyword(s):  
Microbial Diversity ◽  
Ecosystem Functioning ◽  
Functional Redundancy ◽  
The Relationship

scholarly journals Research on Entity Label Value Assignment Method in Knowledge Graph

2021 ◽  
Vol 14 (2) ◽  
pp. 63
Author(s):  
Linqing Yang ◽  
Bo Liu ◽  
Youpei Huang ◽  
Xiaozhuo Li
Keyword(s):  
Conditional Entropy ◽  
Knowledge Graph ◽  
Specific Knowledge ◽  
Relationship Type ◽  
Value Assignment ◽  
External Resources ◽  
Domain Specific ◽  
Assignment Method ◽  
Domain Specific Knowledge ◽  
The Relationship

The lack of entity label values is one of the problems faced by the application of Knowledge Graph. The method of automatically assigning entity label values still has shortcomings, such as costing more resources during training, leading to inaccurate label value assignment because of lacking entity semantics. In this paper, oriented to domain-specific Knowledge Graph, based on the situation that the initial entity label values of all triples are completely unknown, an Entity Label Value Assignment Method (ELVAM) based on external resources and entropy is proposed. ELVAM first constructs a Relationship Triples Cluster according to the relationship type, and randomly extracts the triples data from each cluster to form a Relationship Triples Subset; then collects the extended semantic text of the entities in the subset from the external resources to obtain nouns. Information Entropy and Conditional Entropy of the nouns are calculated through Ontology Category Hierarchy Graph, so as to obtain the entity label value with moderate granularity. Finally, the Label Triples Pattern of each Relationship Triples Cluster is summarized, and the corresponding entity is assigned the label value according to the pattern. The experimental results verify the effectiveness of ELVAM in assigning entity label values in Knowledge Graph.

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