scholarly journals The importance of being coupled: Stable states and catastrophic shifts in tidal biomorphodynamics

2010 ◽  
Vol 115 (F4) ◽  
Author(s):  
Marco Marani ◽  
Andrea D'Alpaos ◽  
Stefano Lanzoni ◽  
Luca Carniello ◽  
Andrea Rinaldo
Keyword(s):  
Stable States ◽  
Catastrophic Shifts

scholarly journals Population dynamics of synthetic Terraformation motifs

2016 ◽  
Author(s):  
Ricard V. Solé ◽  
Raúl Montañez ◽  
Salvador Duran Nebreda ◽  
Daniel Rodriguez-Amor ◽  
Blai Vidiella ◽  
...  
Keyword(s):  
Habitat Degradation ◽  
Ecological Engineering ◽  
Ecological Interactions ◽  
Stable States ◽  
Population Extinction ◽  
Intensive Exploitation ◽  
Engineering Designs ◽  
Synthetic Organisms ◽  
Multiple Stable States ◽  
Catastrophic Shifts

Ecosystems are complex systems, currently experiencing several threats associated with global warming, intensive exploitation, and human-driven habitat degradation. Such threats are pushing ecosystems to the brink of collapse. Because of a general presence of multiple stable states, including states involving population extinction, and due to intrinsic nonlinearities associated with feedback loops, collapse can occur in a catastrophic manner. Such catastrophic shifts have been suggested to pervade many of the future transitions affecting ecosystems at many different scales. Many studies have tried to delineate potential warning signals predicting such ongoing shifts but little is known about how such transitions might be effectively prevented. It has been recently suggested that a potential path to prevent or modify the outcome of these transitions would involve designing synthetic organisms and synthetic ecological interactions that could push these endangered systems out of the critical boundaries. Four classes of such ecological engineering designs orTerraformation motifshave been defined in a qualitative way. Here we develop the simplest mathematical models associated with these motifs, defining the expected stability conditions and domains where the motifs shall properly work.

Multiple Stable States and Catastrophic Shifts in Ecosystems

Ecology ◽  
2019 ◽  
Author(s):  
Sonia Kéfi
Keyword(s):  
Alternative Stable States ◽  
Direct Consequence ◽  
Theoretical Models ◽  
Economic Consequences ◽  
Design Management ◽  
Stable States ◽  
Natural Systems ◽  
Restoration Strategies ◽  
Multiple Stable States ◽  
Catastrophic Shifts

The idea that ecosystems may have multiple alternative stable states dates back to the late 1960s–early 1970s, when ecologists realized that this type of behavior could arise in simple mathematical models. A direct consequence is that such ecosystems can suddenly switch (or “tip”) between their alternative stable states rather than gradually responding to changes. In other terms, in these ecosystems, a small environmental perturbation can cause large, discontinuous, and irreversible changes, referred to as catastrophic shifts. This idea has attracted increasing interest in the literature over the years, and has become even more relevant in the current context of global change. Examples of catastrophic shifts in ecosystems include the eutrophication of shallow lakes, the desertification of drylands, and the degradation of coral reefs. Theoretical models have investigated the conditions under which alternative stable states and catastrophic shifts occur. A well-recognized cause of alternative stable states is the presence of strong positive—or self-reinforcing—feedback processes that maintain each of the stable ecosystem states. Understanding the mechanisms underlying the emergence of alternative stable states can help design management as well as restoration strategies for ecosystems. Because catastrophic shifts can have dramatic ecological and economic consequences, approaches have been proposed to detect possible alternative stable states in natural systems, and indicators of approaching ecosystem transitions have been identified (so-called early warning signals of critical slowing down).

Fire Feedbacks with Vegetation and Alternative Stable States

2009 ◽  
Vol 18 (1) ◽  
pp. 159-173 ◽  
Author(s):  
Brian Beckage ◽  
Chris Ellingwood ◽  
Keyword(s):  
Alternative Stable States ◽  
Stable States ◽  
Fire Feedbacks

Multi- and In-Stabilities in Gas Partitioning Between Nanoporous Materials and Rubber Balloons

2018 ◽  
Author(s):  
Cory Simon ◽  
carlo carraro
Keyword(s):  
Thermodynamic Equilibrium ◽  
Stable States ◽  
Temperature Changes ◽  
Adsorbed Gas ◽  
Rubber Balloon ◽  
Balloon Size ◽  
Metal Organic ◽  
Balloon Experiment ◽  
Adsorbent System ◽  
Balloon System

<div>In the two-balloon experiment, two rubber balloons are connected and allowed to exchange gas. Owing to the non-monotonic relationship between the radius of the balloon and the pressure of gas inside of it, the two-balloon system presents multi- and in-stabilities.</div><div><br></div><div>Herein, we consider a two-adsorbent system, where two different adsorbents are allowed to exchange gas. We show that, for rigid adsorbents, the thermodynamic equilibrium state is unique.</div><div><br></div><div>Then, we consider an adsorbent-balloon system, where an adsorbent exchanges gas with a rubber balloon. This system can exhibit multiple states at thermodynamic equilibrium-- two (meta)stable and one unstable. The size of the balloon, pressure of gas in the balloon, and partitioning of gas between the adsorbent and the balloon differ among the equilibrium states. Temperature changes and the addition/removal of gas into/from the adsorbent-balloon system can induce catastrophe bifurcations and show hysteresis. Furthermore, the adsorbent-balloon system exhibits a critical temperature where, when approached from below, the discrepancy of balloon size between the two (meta)stable states decreases and, beyond, bistability is impossible.</div><div><br></div><div>Practically, our findings preclude multiple partitions of adsorbed gas in rigid mixed-linker metal-organic frameworks and may inspire new soft actuator and sensor designs.</div>

scholarly journals A Study of Taxi Service Mode Choice Based on Evolutionary Game Theory

2019 ◽  
Vol 2019 ◽  
pp. 1-17
Author(s):  
Zhu Bai ◽  
Mingxia Huang ◽  
Shuai Bian ◽  
Huandong Wu
Keyword(s):  
Game Theory ◽  
Evolutionary Game Theory ◽  
Mode Choice ◽  
Evolutionary Game ◽  
Payoff Matrix ◽  
Game Model ◽  
Stable States ◽  
Taxi Service ◽  
Service Mode ◽  
The Impact

The emergence of online car-hailing service provides an innovative approach to vehicle booking but has negatively influenced the taxi industry in China. This paper modeled taxi service mode choice based on evolutionary game theory (EGT). The modes included the dispatching and online car-hailing modes. We constructed an EGT framework, including determining the strategies and the payoff matrix. We introduced different behaviors, including taxi company management, driver operation, and passenger choice. This allowed us to model the impact of these behaviors on the evolving process of service mode choice. The results show that adjustments in taxi company, driver, and passenger behaviors impact the evolutionary path and convergence speed of our evolutionary game model. However, it also reveals that, regardless of adjustments, the stable states in the game model remain unchanged. The conclusion provides a basis for studying taxi system operation and management.

scholarly journals Hierarchical mechanical metamaterials built with scalable tristable elements for ternary logic operation and amplitude modulation

2021 ◽  
Vol 7 (9) ◽  
pp. eabf1966
Author(s):  
Hang Zhang ◽  
Jun Wu ◽  
Daining Fang ◽  
Yihui Zhang
Keyword(s):  
Structural Diversity ◽  
Cell Number ◽  
Structural Elements ◽  
Ternary Logic ◽  
Stable States ◽  
One Dimensional ◽  
Logic Operation ◽  
Artificial Materials ◽  
Mechanical Metamaterials ◽  
Unit Cells

Multistable mechanical metamaterials are artificial materials whose microarchitectures offer more than two different stable configurations. Existing multistable mechanical metamaterials mainly rely on origami/kirigami-inspired designs, snap-through instability, and microstructured soft mechanisms, with mostly bistable fundamental unit cells. Scalable, tristable structural elements that can be built up to form mechanical metamaterials with an extremely large number of programmable stable configurations remains illusive. Here, we harness the elastic tensile/compressive asymmetry of kirigami microstructures to design a class of scalable X-shaped tristable structures. Using these structure as building block elements, hierarchical mechanical metamaterials with one-dimensional (1D) cylindrical geometries, 2D square lattices, and 3D cubic/octahedral lattices are designed and demonstrated, with capabilities of torsional multistability or independent controlled multidirectional multistability. The number of stable states increases exponentially with the cell number of mechanical metamaterials. The versatile multistability and structural diversity allow demonstrative applications in mechanical ternary logic operators and amplitude modulators with unusual functionalities.

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