Asymmetric Behavior Research Articles

Does innovation matter for asymmetric cost behaviour? Evidence from forward citations to the patents

AbstractThis study investigates how innovation affects cost stickiness. Utilising data on patents of US firms between 1991 and 2022, we find that the extent of cost stickiness is greater with a greater number of forward citations for patents. We also find that the main relationship is more pronounced in high‐tech industries, high labour cost intensity, and market competition. In addition, we find that firms with a higher number of patents and forward citation experience a subsequent increase in sales. Overall, this makes a valuable addition to the extant literature, proposing that patents serve as an alternative driver of cost stickiness.

Understanding Electrolyte Ion Size Effects on the Performance of Conducting Metal-Organic Framework Supercapacitors.

Layered metal-organic frameworks (MOFs) have emerged as promising materials for next-generation supercapacitors. Understanding how and why electrolyte ion size impacts electrochemical performance is crucial for developing improved MOF-based devices. To address this, we investigate the energy storage performance of Cu3(HHTP)2 (HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene) with a series of 1 M tetraalkylammonium tetrafluoroborate (TAABF4) electrolytes with different cation sizes. Three-electrode experiments show that Cu3(HHTP)2 exhibits an asymmetric charging response with all ion sizes, with higher energy storage upon positive charging and a greater charging asymmetry with larger TAA+ cations. The results further show that smaller TAA+ cations demonstrate superior capacitive performances upon both positive and negative charging compared to larger TAA+ cations. To gain further insights, electrochemical quartz crystal microbalance measurements were performed to probe ion electrosorption during charging and discharging. These reveal that Cu3(HHTP)2 has a cation-dominated charging mechanism, but interestingly indicate that the solvent also participates in the charging process with larger cations. Overall, the results of this study suggest that larger TAA+ cations saturate the pores of the Cu3(HHTP)2-based electrodes. This leads to more asymmetric charging behavior and forces solvent molecules to play a role in the charge storage mechanism. These findings significantly enhance our understanding of ion electrosorption in layered MOFs, and they will guide the design of improved MOF-based supercapacitors.

Dynamics of Coalesced Droplet Jumping on Superhydrophobic Surface with Asymmetrically Wettable Ridge

Spontaneous detachment from superhydrophobic surfaces can be induced by the coalescence of two or more adjacent droplets. The phenomena have provided implications for the self-removal of droplets in the fields of self-cleaning, anti-icing, and heat transfer. However, many studies focus mainly on the theoretical jumping direction perpendicular to the substrate, although the velocity in the horizontal direction must be involved in practical applications due to various scenarios. This study analyzes numerically the effect of the distribution in ridge structure’s wettability on the performance of coalesced droplet jumping. The jumping dynamics are discussed for varying contact angle ratios and the aspect ratios of the ridge, which are the initial values for the current model. We obtain the height of the jumping and the offset distance in the horizontal direction under the several initial values. In addition, the characteristics of the asymmetric behavior are discussed based on the temporal evolution of the average velocities of the jumping droplets for each direction. Numerical results show that the horizontal offset distance is significantly pronounced at both the high asymmetry in wettability and the high aspect ratio of the ridge geometry. The phenomenon occurs when the droplet detaches from the ridge surface in the retraction process. We determine the role of the distribution within the ridge structure on its wettability, as well as the role of the aspect ratios of the ridge in facilitating the efficient transport of droplets.

Asymmetric behavior of irreversible weak pinning at the soft/hard magnetically interface revealed by the open recoil loops

Asymmetric behavior of irreversible weak pinning at the soft/hard magnetically interface revealed by the open recoil loops

Investigation of contact behavior on a model of the dual-mobility artificial hip joint for Asians in different inner liner thicknesses.

The four components that make up the current dual-mobility artificial hip joint design are the femoral head, the inner liner, the outer liner as a metal cover to prevent wear, and the acetabular cup. The acetabular cup and the outer liner were constructed of 316L stainless steel. At the same time, the inner liner was made of ultra-high-molecular-weight polyethylene (UHMWPE). As this new dual-mobility artificial hip joint has not been researched extensively, more tribological research is needed to predict wear. The thickness of the inner liner is a significant component to consider when calculating the contact pressure. To make use of finite element analysis to gain a better understanding of the contact behavior in various inner liner thicknesses on a new model of a dual-mobility artificial hip joint, with the ultimate objective of determining the inner liner thickness that was most suitable for this particular type of dual-mobility artificial hip joint. In this study, the size of the femoral head was compared between two diameters (28 mm and 36 mm) and eight inner liner thicknesses ranging from 5 mm to 12 mm. Using the finite element method, the contact parameters, including the maximum contact pressure and contact area, have been evaluated in light of the Hertzian contact theory. The simulation was performed statically with dissipated energy and asymmetric behavior. The types of interaction were surface-to-surface contact and normal contact behavior. The maximum contact pressures in the inner liner (UHMWPE) at a head diameter of 28 mm and 36 mm are between 3.7-13.5 MPa and 2.7-10.4 MPa, respectively. The maximum von Mises of the inner liner, outer liner, and acetabular cup are 2.4-11.4 MPa, 15.7-44.3 MPa, and 3.7-12.6 MPa, respectively, for 28 mm head. Then the maximum von Mises stresses of the 36 mm head are 1.9-8.9 MPa for the inner liner, 9.9-32.8 MPa for the outer liner, and 2.6-9.9 MPa for the acetabular cup. A head with a diameter of 28 mm should have an inner liner with a thickness of 12 mm. Whereas the head diameter was 36 mm, an inner liner thickness of 8 mm was suitable. The contact pressures and von Mises stresses generated during this research can potentially be exploited in estimating the wear of dual-mobility artificial hip joints in general. Contact pressure and von Mises stress reduce with an increasing head diameter and inner liner's thickness. Present findings would become one of the references for orthopedic surgery for choosing suitable bearing geometric parameter of hip implant.

Integration of Decentralized Graph-Based Multi-Agent Reinforcement Learning with Digital Twin for Traffic Signal Optimization

Machine learning (ML) methods, particularly Reinforcement Learning (RL), have gained widespread attention for optimizing traffic signal control in intelligent transportation systems. However, existing ML approaches often exhibit limitations in scalability and adaptability, particularly within large traffic networks. This paper introduces an innovative solution by integrating decentralized graph-based multi-agent reinforcement learning (DGMARL) with a Digital Twin to enhance traffic signal optimization, targeting the reduction of traffic congestion and network-wide fuel consumption associated with vehicle stops and stop delays. In this approach, DGMARL agents are employed to learn traffic state patterns and make informed decisions regarding traffic signal control. The integration with a Digital Twin module further facilitates this process by simulating and replicating the real-time asymmetric traffic behaviors of a complex traffic network. The evaluation of this proposed methodology utilized PTV-Vissim, a traffic simulation software, which also serves as the simulation engine for the Digital Twin. The study focused on the Martin Luther King (MLK) Smart Corridor in Chattanooga, Tennessee, USA, by considering symmetric and asymmetric road layouts and traffic conditions. Comparative analysis against an actuated signal control baseline approach revealed significant improvements. Experiment results demonstrate a remarkable 55.38% reduction in Eco_PI, a developed performance measure capturing the cumulative impact of stops and penalized stop delays on fuel consumption, over a 24 h scenario. In a PM-peak-hour scenario, the average reduction in Eco_PI reached 38.94%, indicating the substantial improvement achieved in optimizing traffic flow and reducing fuel consumption during high-demand periods. These findings underscore the effectiveness of the integrated DGMARL and Digital Twin approach in optimizing traffic signals, contributing to a more sustainable and efficient traffic management system.

Why Does the October Effect Not Occur at Night?

AbstractThe October effect is known as a rapid and strong decrease in the signal amplitude of radio waves with very low frequency (VLF), reflected at the lowest edge of the ionosphere. This strong decrease can be observed only during the daytime. Although the October effect is long known, it is hardly investigated and its mechanism is still unknown. To get closer to a mechanism, we answer why the October effect does not occur during nighttime. Therefore, average characteristics of the October effect are obtained from different VLF transmitter‐receiver combinations. The occurrence of the October effect is then compared with characteristics of the neutral atmosphere temperature at VLF reflection heights as it seems to act as a proxy for the unknown mechanism. The temperature shows an asymmetric seasonal behavior at daytime VLF reflection heights poleward of 50°N but not during the nighttime, resulting in the October effect.

A new yield criterion based constitutive model for porous materials

In the present work, a new explicit expression of macroscopic yield criterion is derived for porous materials, such as soil, rock and cement-based materials. To consider the asymmetric behavior between tensile and compression loading, the matrix is assumed to obey to a Drucker–Prager local criterion. The influence of porosity and the effect of matrix properties are well taken into account by this criterion. By using the stress variational approach with a suitable statically admissible stress field, a new more accurate estimation with a simple expression has been obtained for the case of purely deviatoric loading. The exact solutions can be retrieved by this criterion in the case of hydrostatic loading. It also resolves the problem of discontinuity between tension and compression. The weaknesses of the main existing criteria have been overcome by this new yield criterion. By comparing with the finite element numerical results with a wide range values of porosity and frictional parameter of the matrix, the proposed macroscopic yield criterion has a great accuracy and improves the existing ones. Based on this yield criterion, a complete constitutive model is constructed and implemented. This micro-mechanics based model is then applied to describe the mechanical behavior of porous sandstone, and validated by the comparisons with experimental results at different confining pressures.

Dampened Transient Actuation of Hydrogels Autonomously Controlled by pH-Responsive Bicontinuous Nanospheres.

The fabrication of a soft actuator with a dampened actuation response is presented. This was achieved via the incorporation into an actuating hydrogel of urease-loaded pH-responsive bicontinuous nanospheres (BCNs), whose membrane was able to regulate the permeability and thus conversion of fuel urea into ammonia. The dampened response of these nanoreactors to the enzymatically induced pH change was translated to a pH-responsive soft actuator. In hydrogels composed of a pH-responsive and nonresponsive layer, the transient pH gradient yielded an asymmetric swelling behavior, which induced a bending response. The transient actuation profile could be controlled by varying the external fuel concentrations. Furthermore, we showed that the spatial organization of the BCNs within the actuator had a great influence on the actuation response. Embedding the urease-loaded nanoreactors within the active, pH-responsive layer resulted in a reduced response due to local substrate conversion in comparison to embedding them within the passive layer of the bilayer hydrogel. Finally, we were able to induce transient actuation in a hydrogel comprising two identical active layers by the immobilization of the BCNs within one specific layer. Upon addition of urea, a local pH gradient was generated, which caused accelerated swelling in the BCN layer and transient bending of the device before the pH gradient was attenuated over time.

Near-unity asymmetric transmission of linearly polarized light with high Q-factor based on the coherent coupling of dual resonances in bilayer dielectric chiral metasurfaces

This report shows that near-unity asymmetric transmission (AT) of linearly polarized light with high Q-factor can be realized in bilayer dielectric chiral metasurfaces, the unit cell of which consists of silicon slab with rectangular holes on its both sides which are arranged perpendicularly to each other. The preceding work has revealed that the theoretical upper limit of the AT is given as the amplitude reflection coefficient of background system without nanostructure, when a single resonance mainly contributes. If double resonances with overlapping spectral shapes concurrently contribute to the AT, however, their coherent coupling enables breaking the above upper limit and near-unity AT can be obtained. As one of the contributing resonances in the metasurface is quasi-BIC, the resultant AT has also high Q-factor in addition to the near-unity value. Thus, the presented photonic system exhibits highly efficient asymmetric third-harmonic generation behavior, which has the efficiency ratio between forward and backward pumping in the orders from several hundreds to thousands. High-Q near-unity AT shown in this work will find practical applications for direction-dependent nonlinear frequency conversion, information processing, optical sensing, and polarization multiplexing.

Wall confinement effects on the dynamics of cavitation bubbles in thin tubes

Cavitation is a common phenomenon in nature and has numerous applications. In contrast to a cavitation bubble in a free domain, a cavitation bubble in a thin tube is restricted by the tube wall, which is expected to significantly affect bubble evolution, but its mechanism is still unclear. In this study, the dynamics of a cavitation bubble in a thin circular tube is studied by numerical simulation, focusing on the confinement effects of the tube. The results show that besides affecting the size and lifetime of the bubble, the confinement effects of the tube lead to the generation of counter jets and a ring jet during the contraction process of the bubble, and the curvature of the two counter jets determines the ring jet's peak velocity. When the bubble deviates from the midpoint of the tube in the axial direction, the two sides of the bubble along the axial direction show asymmetric behaviors, which results in the bubble migrating toward the midpoint. The tube diameter, tube length, liquid viscosity, and initial bubble position can significantly influence the degree of confinement effects, which can be characterized by the variations of several key indicators, such as bubble size, lifetime, degree of deformation, counter jet velocity, ring jet velocity, and axial migration of the bubble.

Fiscal regimes and debt sustainability in Colombia

ABSTRACT This paper evaluates Colombia’s debt sustainability for the period 1980–2021, using a nonlinear fiscal reaction function approach. We employ a Markov-Switching model with annual data to identify sustainable and unsustainable fiscal regimes. According to this model, we identified an unsustainable fiscal regime during three periods with an average duration of six years − 1980–1985, 1993–1999, and 2015–2021 – while the other periods are identified as a sustainable regime. Although we find evidence of asymmetric behaviour in fiscal responses and the presence of pro-cyclical fiscal policy, Colombia’s long-term fiscal sustainability is verified based on a globally-based fiscal sustainability test. In this context, the government reacts appropriately to increases in debt only in the sustainable regime, but the fiscal response is sufficiently robust to stabilise public debt throughout the entire period. Finally, we also highlight concerns regarding the current state of the global economy, particularly due to an inflationary trend and escalating interest rates, which can compromise long-term fiscal sustainability.

Assessing the asymmetric cost behavior in China

PurposeA country’s institutional environment influences every facet of its business. This paper aims to identify institutional factors (state ownership, government attention on employment and employees’ educational background) that affect the asymmetric cost behavior in China.Design/methodology/approachUsing 2,570 listed firms’ data between 2002 and 2015, we use empirical models to explore the effects of state ownership, government attention on employment and employees’ educational background on the asymmetric cost behavior in China.FindingsThis study found that the asymmetric cost behavior of central state-owned enterprises (CSOEs) is greater than local state-owned enterprises (LSOEs). Meanwhile, the empirical results show that government attention on employment is reflected in five-year government plans, and employees’ educational backgrounds are positively associated with asymmetric cost behavior.Originality/valueThis study contributes to the economic theory of sticky costs, institutional theory and asymmetric cost behavior literature by providing evidence that shows how government intervention and employee educational background limit the flexibility of corporate cost adjustments. Additionally, this study provides guidance to policymakers by showing how government long-term plans affect firm-level resource adjustment decisions.

Symmetric physically unclonable functions of the arbiter type

Objectives. The problem of constructing a new class of physically unclonable functions of the arbiter type (APUF) that combines the advantages of both classical and balanced APUF is solved. The relevance of such a study is associated with the active development of physical cryptography. The following goals are pursued in the work: research and analysis of classical APUF, construction of a new mathematical model of APUF and development of a new basic element of APUF.Methods. The methods of synthesis and analysis of digital devices are used, including those based on programmable logic integrated circuits, the basics of Boolean algebra and circuitry.Results. It has been established that classical APUF uses a standard basic element that performs three functions, namely, the function of generating two random variables Generate, the function of choosing a pair of paths Select and the function of switching paths Switch, which are specified by one bit of the challenge. It is shown that the joint use of these functions, on the one hand, makes it possible to achieve high characteristics of the APUF, and on the other hand, leads to the formation of an asymmetric behavior of the APUF. In order to analyze the main characteristics of APUF and their ideal behavior, a new mathematical model of APUF was considered, similar to the model of random coin toss. To implement APUF functioning according to the proposed model, a new basic element was developed. It is shown that the use of the proposed basic element allows to build symmetrical physically unclonable functions (C_APUF), which differ from the classical APUF in that the Generate, Select and Switch functions of the basic element are performed by their independent components and are specified by different bits of challenge.Conclusion. The proposed approach to the construction of symmetrical physically unclonable functions, based on the implementation of the Generate, Select and Switch functions by various components of the base element, has shown its efficiency and promise. The effect of improving the characteristics of similar C_APUF has been experimentally confirmed, and, first of all, a noticeable improvement in their probabilistic properties expressed in equal probability of responses. It seems promising to further develop the ideas of building C_APUF, experimental study of their characteristics, as well as analysis of resistance to various types of attacks, including using machine learning.

Asymmetric tension-compression mechanical behaviors of extruded Mg-4.58Zn-2.6Gd-0.18Zr alloy with double-peak fiber texture

To clarify asymmetric mechanical behaviors of the extruded Mg-4.58Zn-2.6Gd-0.18Zr alloy during room temperature tension and compression, the evolution of microstructure, texture and strain hardening rate were systematically investigated when loading along the extrusion direction (ED). The results found that the as-extruded alloy exhibited <101̅0>-<112̅0> double-peak fiber texture, leading to obvious tension compression yield asymmetry and compressive yield plateau. Fiber texture kept stable and only texture intensity gradually decreased with the increasing tensile strain, while fiber texture was exhausted due to the extension twinning and <0001> texture component was aggravated with the increasing compressive strain. Moreover, twinning parts within grains with <101̅0> fiber texture was re-oriented to the c-axis paralleling to the ED, and that in <112̅0> fiber texture deviated about 30° away from the ED. This soft orientation would be finally rotated to the <0001> paralleling to the ED under the action of basal <a> slip, explaining why the <0001> pole dispersed at first and then concentrated with the increasing compressive strain. Three stages of strain hardening rate were both observed for tensile and compressive tests, while increment of Stage II was only observed under compression. Stage II in compression could be further divided into two parts with different slopes. Such phenomenon was seldom reported in Mg alloys, which was caused by different propagation and re-orientation of extension twinning in double-peak fiber texture, and weakened the effect of twin lamella segmentation with the increasing compressive strain. Findings in this work given us a better understanding of asymmetric tensile-compressive mechanical behaviors of extruded Mg alloys with double-peak fiber texture.

Dynamics of a bubble-pair between two parallel rigid walls

The dynamics of two gas bubbles placed side-by-side in liquid between parallel rigid plates is studied numerically using the multiphase volume of fluid (VOF) model in OpenFOAM. This model solves a single set of Navier–Stokes equations for both the gas in the bubbles and the surrounding liquid. Being initially stationary, the bubbles first expand to their maximum volume due to the high gas pressure inside them and then collapse. Both phases are treated as viscous and immiscible without any phase change. The model is validated against available experimental data of a single bubble oscillation between parallel plates and a bubble-pair oscillation near a single rigid wall. Parametric studies are then performed, with the main variables being the initial sizes of the bubbles and their standoff distances from the rigid plates. The bubbles exhibit symmetric or asymmetric behavior depending on these two variables. Three distinct scenarios are identified in the symmetric case based on the relative influence of bubble-bubble and bubble-wall interactions. The jet strength and direction, bubble oscillation period, coalescence, and early asymmetric bubble collapse are characterized by initial distances and radii. This study provides valuable insights into intricate hydrodynamic interactions and behaviors of bubble pairs bounded by rigid surfaces.

Asymmetric repulsive force model: A new car-following model with psycho-physical characteristics

Dynamic traffic phenomena, such as hysteresis, stop-and-go traffic, stability, and capacity drop, have significant implications for traffic safety and congestion. Previous studies have suggested that these phenomena are caused by human behavior. However, existing models have not been able to fully reproduce these dynamic traffic phenomena. The focus of our research is on psycho-physical properties and asymmetric behavior, among other human factors, which provide a theoretical explanation for dynamic traffic phenomena. We propose a new car-following model, Asymmetric Repulsive force Model (ARM), based on the common fundamental mechanisms of the two theories. ARM is evaluated from both microscopic and macroscopic perspectives. ARM exhibited similar driving behavior similar to NGSIM data in the time-distance, speed, acceleration, speed-spacing, and spacing-relative speed domains. Additionally, ARM outperforms comparable models in quantitative evaluations of describing trajectory and hysteresis. From the macroscopic perspective, platoon simulation was performed to analyze stop-and-go situations. The results confirmed that ARM can simulate the processes of speed drop, speed recovery and flow non-recovery, and speed and flow recovery. This finding is consistent with previous research on capacity drop using empirical data and suggests that ARM has the potential to simulate various macroscopic traffic phenomena.

A theoretical model for wave attenuation by vegetation considering current effects

A new theoretical model is derived to predict wave attenuation in an emerged vegetation domain under current influences by considering the current effects on changing both wave group velocity and energy dissipation rate. Considering the current effect on changing wave group velocity, the theory predicts an asymmetric behavior of wave decay in following and opposing currents, different from the earlier theory that predicts a symmetry decay behavior by ignoring the current effect on wave group velocity. The new theory dictates that as the current speed increases, the rate of wave decay changes from the traditionally reciprocal law to the exponential law, where the mixed exponential and reciprocal decay law exists under intermediate current conditions. Furthermore, the present theory can be reduced to an explicit expression of the drag coefficient for weak and strong current conditions. In addition, the theory shows that the decay rate depends on both incident wave amplitude and current velocity when the current velocity is relatively small to wave orbital velocity, whereas it is independent of incident wave amplitude when the current is strong. All of these wave decaying characteristics predicted by the theory have been confirmed by the available experimental data and the numerical results from a 2D RANS model (NEWFLUME).

Smart Strategies for Managing Regional Assets: Best Practices in Increase Local Revenue

This study aims to analyze the optimization of asset management consisting of the process of planning, implementing, and supervising regional property. The research method uses a qualitative approach with a phenomenological orientation. The data obtained from the study were analyzed using interactive models. The results showed weaknesses in the stages of planning, implementation, and supervision of assets. Therefore, the strategy to increase regional original revenue (PAD) through the optimization of regional property (BMD), the Gorontalo Provincial Government can take a series of innovation-oriented actions including: 1) A comprehensive asset audit of all assets owned including land, buildings, facilities, and inventory. This audit should include an assessment of the value, condition, and potential reuse. 2) Development of an asset management plan. 3) Involving private parties and communities to identify opportunities for cooperation in asset management. 4) Utilization of software technology to help monitor inventory, maintenance, and sustainability of assets. 5) Data-driven asset management by identifying new trends, market needs, and revenue potential to aid smarter decision-making processes related to asset utilization. 6) Promotion and marketing of assets that can be carried out by regional apparatus organizations (OPD) if they have facilities that can be leased or used commercially to help increase revenue. 7) Improved policies and regulations including procedures for leasing, maintaining, and reusing assets, as clear and flexible policies can support innovation and better asset utilization. The weakness in this study is mainly localisation, which is related to areas that predominantly prioritize local cultural values as the main foundation in their interaction with the surrounding environment. This is due to limitations in consideration of cultural variations that may exist outside the scope of those regions in this study. Therefore, the results of this study require careful consideration when applied in areas that have different cultural diversity or backgrounds.&#x0D; Keywords: goverment entities, asymmetric behavior, stabilization

The short board effect of ESG rating and corporate green innovation activities.

This article aims to investigate whether differences in ESG ratings have an impact on corporate green innovation behavior. A high-order fixed effects model was established using panel data from Chinese companies from 2009 to 2022 to empirically test the impact of ESG rating divergence in the Chinese market on corporate green innovation behavior.The study demonstrates that ESG rating disparity raises the quantity but lowers the quality of businesses' green innovation efforts because of the short board effect. After a series of robustness tests, the results are still valid.The mechanism investigation reveals that both an external pressure channel and an internal strategy adjustment channel are responsible for the impact of ESG rating disparity on green innovation efforts. The asymmetry of corporate green innovation activities is exacerbated by managers' self-interest, whereas the asymmetry of green innovation is mitigated by the caliber of government. According to the heterogeneity analysis, the divergence of a business's ESG rating between large-scale, non-heavy polluting, and places with strong environmental regulations can effectively slow down the asymmetric behavior of enterprise innovation activities. Additional investigation reveals that the phenomenon of ESG rating divergence spreads across industries and geographical areas. The short board effect of ESG rating divergence can be effectively mitigated by improving the quality of enterprise information disclosure and speeding up the digital transformation of businesses. The research conclusion provides marginal contributions on how to improve China's ESG rating system and how enterprises can identify ESG rating differences and make scientific decisions.