Dependence Of Asymmetry Research Articles

Dependence of divertor asymmetries on the toroidal magnetic field

A study of the effect of toroidal magnetic field (Bt) on the divertor asymmetries is carried out with a plasma transport code under BOUT++ framework with the magnetic equilibria from EAST and C-Mod. For the simulation cases with drifts, the density is larger at the inner divertor target, while the temperature and heat flux are larger at the outer divertor target. The ratio of the total particle flux at the outer target to that of the inner target increases with increasing Bt, while the ratio of the total heat flux at the outer target to that of the inner target decreases with increasing Bt. The in–out divertor asymmetries of both total particle and heat fluxes get weaker with increasing Bt. Further analysis shows that the edge radial transport induced by drifts is much weaker for the simulation case with higher Bt, indicating that drift-driven divertor asymmetries may be less important for future tokamaks with high Bt.

Can digital transformation promote hospitality and tourism firms’ investment? Moderating effect of financing constraints and economic policy uncertainty

ABSTRACT Research on corporate investment is widely acknowledged as essential in the realm of financial management within the hospitality and tourism sector. Drawing on information asymmetry and resource dependency theories, this study examines the effect of digital transformation on hospitality and tourism firm investment and explores how financing constraints and economic policy uncertainty moderate these effects. We utilized firms engaged in tourism, hotel, catering, and transportation, listed on the A-share market of China’s Shanghai and Shenzhen stock exchanges from 2009 to 2022, as our research sample. Our findings indicate that digital transformation enhances investment in hospitality and tourism companies. Furthermore, this positive effect was more pronounced for firms with reduced financing constraints and heightened economic policy uncertainty. These findings reveal ignored tourism and hospitality investment antecedents and enrich academic understanding by expanding firm-specific boundaries. This study provides practical insight into how hospitality and tourism firms can boost investment through digital transformation.

Counterfactual power and genuine choice

AbstractThe article introduces a distinction between weak and strong counterfactual power and shows that as far as the metaphysical aspect of choice is concerned, T. Merricks's examples do not undermine the proposition that strong counterfactual power over a fact suffices for having a genuine choice about that fact. This is relevant to debates about logical fatalism, theological incompatibilism and nomological (determinism) incompatibilism. If strong counterfactual power is sufficient for having a choice, then in each of the main arguments for the mentioned stances, the negation of the argument's conclusion entails the negation of its key premise. It is further argued that those key premises cannot be justified by the fixity of the past because the latter holds only to the extent warranted by the asymmetry of counterfactual dependence between the past and the future. Therefore, the pastness of such facts as that propositions about our acts were true before we were born, and that God believed then that we would perform those acts, does not provide any reason to believe that we do not have a choice about those facts. Fatalists and incompatibilists assume in their arguments something that has yet to be justified.

Government debt and economic growth: heterogeneity, asymmetries, and the role of net debt

ABSTRACT Using data on 167 countries over 1970–2019, this study gathers new evidence about the government debt-growth relationship. We jointly address several features of the panel – foremost asymmetry, cointegration, endogeneity, country heterogeneity and cross-sectional dependence. We find that increases in per-worker debt are detrimental to the long-run dynamics of output, but our nonlinear estimates suggest that changes in government debt propagate their effects through different channels. Applying alternatively gross and net public debt as a measure of indebtedness yields different results too, as happens with the adoption of different estimators. The magnitude of the effects depends on the model specification, indicating that cross-country estimates of the debt-growth nexus require parsimonious interpretations.

A non‐stationary factor copula model for non‐Gaussian spatial data

AbstractWe introduce a new copula model for non‐stationary replicated spatial data. It is based on the assumption that a common factor exists that controls the joint dependence of all the observations from the spatial process. As a result, our proposal can model tail dependence and tail asymmetry, unlike the Gaussian copula model. Moreover, we show that the new model can cover a full range of dependence between tail quadrant independence and tail dependence. Although the log‐likelihood of the model can be obtained in a simple form, we discuss its numerical computational issues and ways to approximate it for drawing inference. Using the estimated copula model, the spatial process can be interpolated at locations where it is not observed. We apply the proposed model to temperature data over the western part of Switzerland, and we compare its performance with that of its stationary version and with the Gaussian copula model.

State of charge estimation with hysteresis-prone open circuit voltage in lithium-ion batteries using the trajectory correction hysteresis (TCH) model

State-of-the-art lithium-ion cell chemistries with pronounced open-circuit voltage hysteresis (OCV), characterised by asymmetry and directional dependence, present a challenge for estimating the state of charge (SOC). Without understanding the hysteresis behaviour, OCV measurement points that lie within the hysteresis window cannot be used for SOC correction. After obtaining the data efficiency of the trajectory correction hysteresis (TCH) model with the introduction of the transfer fit (TF) method, this work applies the TF TCH for OCV-based SOC correction. The TF method plays a key role as it enables the cell-specific adaptation of an existing TCH model - ageing update is achieved with solely 12 (SOC/OCV) measurement points. With the precise hysteresis model, the developed framework successfully corrects the faulty SOC history, which could originate from a vehicle data logger. Given that two OCV measurement points are available that arbitrarily lie within the SOC history, the SOC correction is achieved by minimising the voltage deviation between the measurement points and the TCH model’s simulation. Identifying the two SOC parameters shift and scale enables subsequent SOC estimation until an additional OCV measurement is available for a further update. The functionality of the presented SOC correction framework is demonstrated using two validation profiles.

Enhanced Fano resonances in a silicon nitride photonic crystal nanobeam-assisted micro ring resonator for dual telecom band operation

Silicon-based Micro Ring Resonators (MRR) are a powerful tool for the realization of label free optical biosensors. The sharp edge of a Fano resonance in a Silicon Nitride (Si3N4) platform can boost photonic sensing applications based on MRRs. In this work, we demonstrate enhanced Fano resonance features for a Si3N4 Micro Ring Resonator assisted by a Photonic Crystal Nanobeam (PhCN-MRR) operating in the TM-like mode at the O-band wavelengths. Our findings show that the fabricated PhCN-MRR results in increased asymmetric resonances for TM-like mode compared with TE-like mode operation in the C-band. As a result, a versatile and flexible design to realize Fano resonance with polarization dependent asymmetry in the C and O telecom bands is presented.

On the habit planes between elastically distorted austenite and martensite in NiTi

The cubic B2 to monoclinic B19’ martensitic transformation in NiTi shape memory alloys proceeds by the nucleation and propagation of habit plane interfaces that remain undistorted and unrotated during the transformation. Due to incompatibility of austenite and martensite lattices in NiTi, habit plane interfaces are assumed to form between austenite and twinned martensite as described by Phenomenological Theory of Martensite Crystallography (PTMC). This view is currently widely spread in the literature in spite of the fact that it contradicts experimental observations of interfaces between austenite and single martensite lattice by TEM and EBSD methods frequently reported in the literature. On this account, we propose a different solution for the formation of strain compatible habit planes propagating during stress induced martensitic transformation by considering the effect of elastic deformation of both lattices caused by the external stress. Using modified PTMC theory, we evaluate the magnitudes of the uniaxial stress in tension and compression along a general austenite crystal direction, for which strain compatible habit plane interfaces can be established between austenite and single variant of martensite. The stress calculated in such a way is, however, too high. Nevertheless, considering the pre-transformation softening of austenite, the critical stress decreases to 500 MPa commonly observed in experiments. Three scenarios are simulated assuming softening of elastic constants of austenite. Orientation dependence and tension-compression asymmetry of predicted habit planes of stress induced martensitic transformation is compared with available experimental results.

Managing Asymmetries for Data Mobilization under Digital Transformation

AbstractResource mobilization is a significant challenge for firms seeking survival and competitive advantage, especially in the context of digital transformation. Data has emerged as a vital resource, but its intangible nature adds complexity to the interactions between resource holders and seekers. This paper aims to address the gaps in understanding data resource mobilization by integrating perspectives on information, dependence, and orientation asymmetry using a social exchange perspective. The study focuses on the regulated animal healthcare industry, where a large established organization acts as the resource holder, universities act as intermediaries, and startups act as resource seekers. Through three years of data collection, the study finds that the context is rich in all three types of asymmetries and characterized by high uncertainty surrounding data as a resource. Actors engage in direct social exchanges to address information asymmetries and in generalized exchanges through intermediaries to deal with dependence and orientation asymmetries. The study contributes to theory by providing insights into the complex dynamics of resource mobilization in the context of digital transformation and proposes practical implications for managing multiple asymmetries and mobilizing data effectively for firm performance in regulated environments.

Phoneme dependence of horizontal asymmetries in voice directivity.

Human voice directivity shows horizontal asymmetries caused by the shape of the lips or the position of the tooth and tongue during vocalization. This study presents and analyzes the asymmetries of voice directivity datasets of 23 different phonemes. The asymmetries were determined from datasets obtained in previous measurements with 13 subjects in a surrounding spherical microphone array. The results show that asymmetries are inherent to human voice production and that they differ between the phoneme groups with the strongest effect on the [s], the [l], and the nasals [m], [n], and [ŋ]. The least asymmetries were found for the plosives.

Urbanisation and agricultural intensification modulate plant–pollinator network structure and robustness

Abstract Land use change is a major pressure on pollinator abundance, diversity and plant–pollinator interactions. Far less is known about how land‐use alters the structure of plant–pollinator networks and their robustness to plant–pollinator coextinctions. We analysed the structure of plant–pollinator networks sampled in 12 landscapes along an urbanisation and agricultural intensity gradient, from early spring to late summer 2021, and used a stochastic coextinction model to correlate plant–pollinator coextinction risk with network structure (species and network‐level metrics) and landscape context. Networks in intensively managed (i.e., agricultural and urban) landscapes had a lower risk of initiating a coextinction cascade, while networks in less intensively managed landscapes may be less robust. Network structure modulated the frequency and severity of coextinctions and species loss, while the strength of species interactions increased robustness. Urban networks were more species rich and symmetrical due to the high diversity of ornamental plants, while intensively managed agricultural landscapes had smaller, more tightly connected and nested networks. Network structure modulated the frequency of extinctions, which was decreased by greater linkage density, interaction asymmetry and interaction dependence in the networks, while once an extinction occurred, nestedness and linkage density propagated the degree of the coextinction cascade and species loss. At the species level, species strength was inversely correlated with extinction risk, implying that generalist species with a high number of interactions with specialists had the lowest extinction risk. An interplay between land‐use and network structure affects community robustness to coextinctions with implications for pollination services and plant reproduction. Land‐use change or other global change pressures by reorganising species interactions can alter communities and their potential functioning. Read the free Plain Language Summary for this article on the Journal blog.

When Does Familiarity Manifest its Dark Side in the Construction Industry: Moderating Roles of Task Uncertainty and Dependence Asymmetry

When Does Familiarity Manifest its Dark Side in the Construction Industry: Moderating Roles of Task Uncertainty and Dependence Asymmetry

Influence of generalist stingless bees on the structure of mutualistic flower–pollinator networks in the tropics: Temporal variation

Abstract Stingless bees (Meliponini) are expected to play a central role in structuring mutualistic networks in the Neotropics, as they are generalist and often abundant pollinators. Living in populous social colonies with a perennial life cycle, they require continuous large amounts of resources and often forage on abundant flowerings such as mass‐flowering throughout the year. In this field research, we seek to understand how temporal variations on foraging activity of stingless bees and abundance of mass‐flowering partner plants affect the topology of the plant–pollinator mutualistic networks. The networks were compared between spring and summer, periods of high and low abundances of flowerings and mass‐flowering, respectively. Bees were sampled on flowers, in replicates of floodplain fields in Atlantic Forest of southern Brazil. Interactions with partner plants were considered effective only when bees had pollen on their bodies (potential pollinators). Through analysis of pollen grains attached to their bodies, several topological metrics of networks and functional categories were obtained. The robustness or networks resistance to secondary species loss due to simulated focal species extinction was also measured. The networks maintained similar general structure throughout the year (high nestedness, moderate modularity and connectance, low community‐level specialisation and negative dependency asymmetry). Particularly, nestedness and dependency asymmetry did not change between the two seasons. Community‐level specialisation was higher in summer, contrary to expectations, when there was a collapse in the supply of floral resources and also a reduction in the abundance and foraging pressure of stingless bees. As there was also a greater number of specialist pollinators in summer, the hypothesis of temporal displacement due to foraging pressure from generalists was proposed. At the same time, stingless bees oscillated between network hubs in spring and connectors in summer, reflecting the variation in their abundance between these two seasons. In spring, the greater concentration of foraging by these generalists in the abundant mass‐flowering probably attenuated their diffuse competitive pressure on all other pollinators, even though the foraging overlap was higher in this period. In this period of high abundance of floral resources, specialist pollinators capable of expanding the realised niche are active. Based on recent theoretical conclusions of dynamic model of mutualistic networks structure that incorporated effects of inter‐specific competition and adaptive foraging, we argue that the adaptive foraging of generalist and abundant stingless bees contributes in an important way to the high nestedness and robustness of networks, which ultimately favour the coexistence of species in the long term. Particularly, taking the high intra‐annual turnover of bee and plant species between the two seasons, and the similar floral constancy of both generalist stingless bees and specialist pollinators, we also infer that stingless bees act as generalised pollinators in the networks rewiring throughout the year.

Default dependence in the insurance and banking sectors: A copula approach

We employ a time-varying asymmetric copula model that combines the generalized autoregressive score model with the generalized hyperbolic skewed t copula to capture the dynamics and asymmetry of default dependence between insurers and banks. We identify the term structure of default dependence between these two sectors. The short-term and long-term dependence of default risk rise and converge during financial crises. We explore the determinants of the time-series variation in default dependence. While traditional macro variables can explain only a small portion of the variation in default dependence, we find a significant negative correlation between default dependence and global geopolitical risk.

Effect of Forced Convection on Magnesium Dendrite: Comparison between Constant and Altering Flow Fields.

Convection has a nonnegligible effect on the growth of the magnesium dendrite with six-primary-branch pattern. Most work, however, investigates the effect of the convection by simplifying the melt flow as a constant horizontal flow. In this work, four convection behaviors, including equally distributed convection, linearly distributed convection, sinusoidal-wave convection, and square-wave convection, are imposed and simulated through the phase-field lattice-Boltzmann schemes. The effects of constant (the former two) and altering (the latter two) flow fields are quantified by the length ratio of the upstream primary arm to the downstream one. The results show that the dendrite asymmetry increases under the constant forced convections but presents nonmonotonic change under the altering convections. A simple mathematical relation is fitted to summarize the dependence of the dendrite asymmetry on the input velocity, the undercooling, and the flow frequency. Deep understanding of the convection effects can guide the prediction and control of the magnesium dendrite under more complex situations.

Aberrant morphometric networks in Alzheimer's disease have hemispheric asymmetry and age dependence.

Alzheimer's disease (AD) is associated with abnormal accumulations of hyperphosphorylated tau and amyloid-β proteins, resulting in unique patterns of atrophy in the brain. We aimed to elucidate some characteristics of the AD's morphometric networks constructed by associating different morphometric features among brain areas and evaluating their relationship to Mini-Mental State Examination total score and age. Three-dimensional T1-weighted (3DT1) image data scanned by the same 1.5T magnetic resonance imaging (MRI) were obtained from 62 AD patients and 41 healthy controls (HCs) and were analysed by using FreeSurfer. The associations of the extracted six morphometric features between regions were estimated by correlation coefficients. The global and local graph theoretical measures for this network were evaluated. Associations between graph theoretical measures and age, sex and cognition were evaluated by multiple regression analysis in each group. Global measures of integration: global efficiency and mean information centrality were significantly higher in AD patients. Local measures of integration: node global efficiency and information centrality were significantly higher in the entorhinal cortex, fusiform gyrus and posterior cingulate cortex of AD patients but only in the left hemisphere. All global measures were correlated with age in AD patients but not in HCs. The information centrality was associated with age in AD's broad brain regions. Our results showed that altered morphometric networks due to AD are left-hemisphere dominant, suggesting that AD pathogenesis has a left-right asymmetry. Ageing has a unique impact on the morphometric networks in AD patients. The information centrality is a sensitive graph theoretical measure to detect this association.

New Perspectives on Spectroscopic Factor Quenching from Reactions.

The evolution of single-particle strengths as the neutron-to-proton asymmetry changes informs us of the importance of short- and long-range correlations in nuclei and has therefore been extensively studied for the last two decades. Surprisingly, the strong asymmetry dependence of these strengths and their extreme values for highly asymmetric nuclei inferred from knockout reaction measurements on a target nucleus are not consistent with what is extracted from electron-induced, transfer, and quasi-free reaction data, constituting a two-decade old puzzle. This work presents the first consistent analysis of one-nucleon transfer and one-nucleon knockout data, in which theoretical uncertainties associated with the nucleon-nucleus effective interactions considered in the reaction models are quantified using a Bayesian analysis. Our results demonstrate that, taking into account these uncertainties, the spectroscopic strengths of loosely bound nucleons extracted from both probes agree with each other and, although there are still discrepancies for deeply bound nucleons, the slope of the asymmetry dependence of the single-particle strengths inferred from transfer and knockout reactions are consistent within 1σ. Both probes are consistent with a small asymmetry dependence of these strengths. The uncertainties obtained in this work represent a lower bound and are already significantly larger than the original estimates.

How Dependence Asymmetry and Explicit Contract Shape Contractor–Subcontractor Collaboration: A Psychological Perspective of Fairness

How Dependence Asymmetry and Explicit Contract Shape Contractor–Subcontractor Collaboration: A Psychological Perspective of Fairness

Topology optimization of multi-material structures considering anisotropic yield strengths

Multi-material structures offer the superior performance and broader designable freedom, and have gained increasing interest benefitting from the advances in additive manufacturing (AM) technique. However, the effect of anisotropic yield strength of these AM-fabricated parts on topology optimization of multi-material structures has so far received little attention. In the current work, an anisotropic strength-based topology optimization method for multi-material structures is developed for maximizing strength performance under total mass constraint, which allows for the consideration of directional dependence and tension-compression asymmetry of yield strengths based on the Tsai-Wu yield criterion. Another challenge for multi-material structures design is that the possible permutations of numerous candidate materials are unlimited, it is impossible that all combinations of multiple candidate materials are tested for the optimal strength performance of multi-material structures. To solve this problem, we propose a preselection method for the inclusion or exclusion of candidate materials based on their elastic properties, yield strengths and densities before optimization. Afterwards, our topology optimization method can automatically find the optimal combination of volume fractions of different candidate materials. Several 2D and 3D numerical examples are investigated for minimizing the maximum of failure indexes of strength for fixed total mass. The advantages of multi-material structures are verified by comparing to single-material designs. The effectiveness of the preselection method of candidate materials is also verified.

Accounting for precipitation asymmetry in a multiplicative random cascade disaggregation model

Abstract. Analytical multiplicative random cascades (MRCs) are widely used for the temporal disaggregation of coarse-resolution precipitation time series. This class of models applies scaling models to represent the dependence of the cascade generator on the temporal scale and the precipitation intensity. Although determinant, the dependence on the external precipitation pattern is usually disregarded in the analytical scaling models. Our work presents a unified MRC modelling framework that allows the cascade generator to depend in a continuous way on the temporal scale, precipitation intensity and a so-called precipitation asymmetry index. Different MRC configurations are compared for 81 locations in Switzerland with contrasted climates. The added value of the dependence of the MRC on the temporal scale appears to be unclear, unlike what was suggested in previous works. Introducing the precipitation asymmetry dependence into the model leads to a drastic improvement in model performance for all statistics related to precipitation temporal persistence (wet–dry transition probabilities, lag-n autocorrelation coefficients, lengths of dry–wet spells). Accounting for precipitation asymmetry seems to solve this important limitation of previous MRCs. The model configuration that only accounts for the dependence on precipitation intensity and asymmetry is highly parsimonious, with only five parameters, and provides adequate performances for all locations, seasons and temporal resolutions. The spatial coherency of the parameter estimates indicates a real potential for regionalisation and for further application to any location in Switzerland.