Energy internet(EI) has developed from concept and theoretical framework to practical operation, attracting more and more attention. The application of complex network analysis(CNA) in EI research is ...conducive to realizing more secure, economic and sustainable distributed renewable energy supply and utilization in cities, and to realizing energy conservation, emission reduction and energy efficiency improvement in low-carbon cities. Based on the development history of EI, this paper introduces regional energy internet(REI) from two aspects of research scope and main characteristics. At the same time, based on reviewing the graph theory(GT) and CNA’s application in energy-related domain, it summarizes the particularity of coupling interconnection between transportation network and social network in REI. The concept of energy self-organization(ESO) and energy community(EC) is introduced based on self-organization theory, meanwhile, the differences and advantages between ESO and previous similar concepts are summarized and compared. On this basis, the key issues of REI are analyzed from the perspective of ECs, including complex network topology modeling, optimal network flow allocation, coordination and complementary control, cascade failure mechanism(the scale of different failures can be enlarged through interdependence) analysis and multi-agent interest interaction game. Meanwhile, main research challenges are summarized and the future work is prospected. Finally, the paper conclude the work and deficiencies—it provides a theoretical basis for realizing a city’s collaborative optimization, independent autonomy and efficient low-carbon operation, and improves the application of CNA in urban REI research.
•The research status of complex network analysis in regional energy internet is summarized.•Two new concepts of energy self-organization and energy community are defined.•The interaction between underlying structure and macro-system of regional energy internet is researched.•The topology model and basic metrics of regional energy internet are researched.•The research challenges and prospects are summarized based on complex network analysis.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Individual pedestrian velocities vary over time and space depending on the crowd size, location of individuals’ within the crowd, and formation of self-organized lanes. We use empirical data to ...explore the spatial fluctuations of pedestrian velocities in bidirectional streams. We find that, unlike ordinary fluids, the velocity profile in bidirectional pedestrian streams does not necessarily follow a hyperbolic form. Rather, the shape of the velocity profile is highly dependent on the formation of self-organized lanes. We also show that the spatial fluctuations of pedestrian velocities along and transverse to the flow direction are widely distributed and can be modeled by a sum of Gaussian distributions. Results suggest that the effect of self-organization phenomenon is strong enough that for the same crowd size, the velocity distribution does not significantly change when pedestrians are highly mixed compared to when separate lanes are formed.
•Measuring pedestrian’s velocity distribution in bi-directional streams.•Measuring pedestrians’ velocity profile in bi-directional streams.•Comparison of stable separated lanes versus dynamic multi lanes.•Observing the significance of the self-organization phenomena.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The formative conditions for bedform spurs and their roles in bedform dynamics and associated sediment transport are described herein. Bedform spurs are formed by helical vortices that trail from the ...lee surface of oblique segments of bedform crest lines. Trailing helical vortices quickly route sediment away from the lee surface of their parent bedform, scouring troughs and placing this bed material into the body of the spur. The geometric configuration of bedform spurs to their parent bedform crests is predicted by a cross‐stream Strouhal number. When present, spur‐bearing bedforms and their associated trailing helical wakes exert tremendous control on bedform morphology by routing enhanced sediment transport between adjacent bedforms. Field measurements collected at the North Loup River, Nebraska, and flume experiments described in previous studies demonstrate that this trailing helical vortex‐mediated sediment transport is a mechanism for bedform deformation, interactions and transitions between two‐dimensional and three‐dimensional bedforms.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Planarian flatworms maintain their body plan in the face of constant internal turnover and can regenerate from arbitrary tissue fragments. Both phenomena require self-maintaining and self-organizing ...patterning mechanisms, the molecular mechanisms of which remain poorly understood. We show that a morphogenic gradient of canonical Wnt signaling patterns gene expression along the planarian anteroposterior (A/P) axis. Our results demonstrate that gradient formation likely occurs autonomously in the tail and that an autoregulatory module of Wnt-mediated Wnt expression both shapes the gradient at steady state and governs its re-establishment during regeneration. Functional antagonism between the tail Wnt gradient and an unknown head patterning system further determines the spatial proportions of the planarian A/P axis and mediates mutually exclusive molecular fate choices during regeneration. Overall, our results suggest that the planarian A/P axis is patterned by self-organizing patterning systems deployed from either end that are functionally coupled by mutual antagonism.
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•A tail-to-head Wnt signaling gradient exists along the planarian A/P axis•The gradient patterns the expression of tail genes, including Wnt components•Autoregulatory feedback governs gradient formation and maintenance•The global A/P pattern depends on mutual tail-head antagonism
The regenerative abilities of planarians depend on long-range signaling gradients. Stückemann, Cleland, Werner et al. show that a tail-to-head Wnt gradient patterns the expression of genes, including gradient-forming Wnt pathway components. Mutual antagonism between the autoregulatory tail gradient and a self-organizing head patterning system governs global A/P patterning and pattern regeneration.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Significance Switching surface topographic patterns in a dynamic way controls properties such as friction, sticking–release, light reflection, aero- and hydrodynamics, self-cleaning, and touch ...experience. We present a method to make coatings which are initially flat but form a spiked surface structure under light exposure. The surface turns flat again immediately as the light switches off. The polydomain liquid crystal provides a convenient method that makes fabrication of responsive coatings significantly easier than previous methods. The polydomain texture is simulated by finite elements and the topographic deformation can be understood in terms of director-dependent absorption and related changes in local order. Moreover, the dynamic creation of free volume further enhances the surface modulation to the record value of 24% of the film thickness.
In this work we propose randomly ordered polydomain nematic liquid crystal polymer networks to reversibly generate notable jagged relief patterns at a polymer coating surface by light illumination. The domain size is controlled by the addition of traces of partly insoluble fluorinated acrylate. The photoresponse of the coating is induced by a small amount of copolymerized azobenzene monomers. Upon exposure to UV light, azobenzene undergoes trans to cis isomerization, resulting in a change in molecular order and packing within each domain. The extent of this effect and its directionality depends on the domain orientation. Localized to domain level, this morphological change forms large 3D spikes at the surface with a modulation amplitude of more than 20% of the initial thickness. The process is reversible; the surface topographical patterns erase within 10 s by stopping the light exposure. A finite element model is applied to simulate the surface topography changes of the polydomain coating. The simulations describe the formation of the topographic features in terms of light absorption and isomerization process as a function of the director orientation. The random director distribution leads to surface structures which were found to be in close agreement with the ones measured by interference microscopy. The effect of domain size on surface roughness and depth modulation was explored and related to the internal mechanical constraints. The use of nematic liquid crystal polydomains confined in a polymer network largely simplifies the fabrication of smart coatings with a prominent triggered topographic response.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
The paper proposes a practice theoretical conceptualization of commons. The first part of the paper asks the question how a convincing conceptualization of commons could look like. Despite of the ...increased attention to the concept of the commons different notions thereof exist. Ostrom and her colleagues often define commons as common pool resources, a specific type of good. The underlying classification is based on different degrees of excludability and subtractability. In the paper this is criticized for disregarding the importance of the social processes at hand. It is argued that instead of being a type of good, commons need to be conceptualized taking the relevant social dimensions into account. Commons are hence conceptualized as the social form of (tangible and/or intangible) matter that is determined by commoning. Commoning creates commons. In the second part the social practices of commoning are argued to be voluntary and inclusively self-organized activities and mediation of peers who aim at satisfying needs. The abstractness of the proposed conceptualization allows to aim at the core of the practices, at finding a way to find the common characteristics or dimensions of these practices, without defining away their ever specific way of being and becoming in the concrete.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The actomyosin cytoskeletal network is responsible for a variety of fundamental cellular processes. Assembly and maintenance of actin networks involve an array of associated regulatory proteins for ...polymerization, branching, crosslinking and contractility-driven self-organization. In this study, we make the unexpected discovery in vitro that myosin VI and myosin X, motor proteins specialized in vesicle transport and filopodia formation, are capable of crosslinking and self-organizing actin into higher-order contractile structures in the absence of other actin-associated proteins. Moreover, myosin VI alone can initiate actin elongation and branching, and assemble branched force-generating networks from crosslinked actin polymers. Additional architectural control is provided by the actin crosslinking proteins α-actinin and fascin. Our data identify critical stages of tension-mediated connectivity in network development and provide a model system for further exploration of the nonequilibrium mechanics of actomyosin self-organization.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
From the perspective of co-production, this article examines how Chinese citizens and governments worked together in fighting against COVID-19 in a health emergency context. Based on observations, as ...well as analyses of policy documents and self-organization cases, this article shows that Chinese citizens and governments collaborated through three different channels in fighting against the virus, but different channels produced different results. First, through residential committees, Chinese governments successfully mobilized most citizens to comply with stay-at-home orders, contact traced and isolated suspected cases through existing networks within the communities. Second, as a formal channel for state–society interaction during the crisis, government-organized nongovernmental organizations (NGOs) failed in bridging demands of the health system and contributions from citizens. Third, self-organizations emerged as a key informal channel for citizens to fight against the virus. The experiences and lessons learned in this citizen–government collaboration in combating the virus may offer some implications for other settings.
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NUK, OILJ, SAZU, UKNU, UL, UM, UPUK
In animal societies as well as in human crowds, many observed collective behaviours result from self-organized processes based on local interactions among individuals. However, models of crowd ...dynamics are still lacking a systematic individual-level experimental verification, and the local mechanisms underlying the formation of collective patterns are not yet known in detail. We have conducted a set of well-controlled experiments with pedestrians performing simple avoidance tasks in order to determine the laws ruling their behaviour during interactions. The analysis of the large trajectory dataset was used to compute a behavioural map that describes the average change of the direction and speed of a pedestrian for various interaction distances and angles. The experimental results reveal features of the decision process when pedestrians choose the side on which they evade, and show a side preference that is amplified by mutual interactions. The predictions of a binary interaction model based on the above findings were then compared with bidirectional flows of people recorded in a crowded street. Simulations generate two asymmetric lanes with opposite directions of motion, in quantitative agreement with our empirical observations. The knowledge of pedestrian behavioural laws is an important step ahead in the understanding of the underlying dynamics of crowd behaviour and allows for reliable predictions of collective pedestrian movements under natural conditions.
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