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The unemployment rate (UR) is the leading macroeconomic indicator used in the credit card loss forecasting. COVID-19 pandemic has caused an unprecedented level of volatility in the labor market variables, leading to new challenges to use UR in the credit risk modeling framework. This paper examines the dynamic relationship between the credit card charge-off rate and the unemployment rate over time.

This study uses quarterly observations of charge-off rates on credit card loans of all commercial banks from Q1 1990 to Q4 2020. Univariate, multivariable, machine learning, and regime-switching time series modeling are employed in this research.

The authors decompose UR into two components – temporary and permanent UR. The authors find the spike in UR during COVID-19 is mainly attributed to the surge in temporary layoffs. More importantly, the authors find that the credit card charge-off rate is primarily driven by permanent UR while temporary UR has little predictive power. During recessions, permanent UR seems to be a stronger indicator than total UR. This research highlights the importance of using permanent UR for credit risk modeling.

The findings in the research can be applied to the credit card loss forecasting and CECL reserve models. In addition, this research also has implications for banks, macroeconomic data vendors, regulators, and policymakers.

The symmetrical valve is usually used in the hydraulic servo control system to control the asymmetrical cylinder, but this system’s structure involves asymmetry, and so its dynamic characteristics are asymmetrical, which causes issues in the control system of symmetric response. The purpose of this paper is to achieve the aim of symmetric control.

In this paper, the authors proposed a method that combined wavelet neural network (WNN) and model reference adaptive control. The reference model determined the dynamic response that the system was expected to achieve, and the WNN adaptive control made the system follow the reference model to achieve the purpose of symmetric control.

The experimental results show that the method can achieve a more accurate symmetric control and position control compared with the solutions via the classical PID control.

The proposed combination of the WNN and the reference model can effectively compensate for the asymmetry of dynamic response of the asymmetric cylinder in forward and return directions, which can be extended to deal with other classes of applications.

In theory, the impact of debt liquidity risk (DLR) on the firm's future growth is ambiguous. This study aims to examine the empirical relationship between the DLR and firms' growth rate using annual data for USA companies from 1976 to 2020.

Given the longitudinal nature of the data, the author uses OLS (ordinary least squares) regression methodology with fixed effects to control for unobserved characteristics that might affect the dependent variable. Instrument variable regression is also used to address the potential endogeneity problem.

The results show that firms having higher DLR, as proxied by more short-term debt, experience lower growth rate. An increase in firms' short-term debt decreases the firms' future growth rate as evidenced by lower assets, revenue and employee growth rate. Moreover, the authors' results show that small firms or firms with more investment opportunities grow fast if the firms take higher DLR. Finally, cyclical firms with higher DLR exhibit lower growth rate during the credit tighten period. The authors' results hold for both the pre-zero lower bound (ZLB) era and ZLB period.

To the authors' best knowledge, this is one of the earliest studies to carefully examine the effects of DLR on firms' growth rate. While prior research finds that firms with higher growth potential, measured by market-to-book (MTB) ratio, use more short-term debt, the authors' research directly addresses whether DLR affects firms' future growth rate. The authors’ findings also help explain why firms with high growth potential use more short-term debt.

The purpose of this paper is to explore the factors affecting users’ continuous microblog usage intention. In recent years, the number of microblog users has gradually declined. This research can reveal microblog users’ needs and provide the improvement direction of microblog services.

By integrating Wixom and Todd’s theoretical framework, the Uses and Gratifications Theory and the DeLone and McLean Information System Success Model, a conceptual model is proposed. In this model, gratification is defined as a kind of behavioral attitude, and satisfaction is viewed as an object-based attitude. The survey data were collected online and analyzed using the partial least squares method.

The results suggest that users’ continuance intention (behavioral intention) is jointly determined by users’ gratification (behavioral-based attitude) and their habitual microblog usage behavior. Likewise, gratification is positively affected by satisfaction (object-based attitude) which is a joint function of system quality and information quality (object-based beliefs).

In this research, Wixom and Todd’s principle is applied as the basic theoretical framework; gratification is viewed as a behavior attitude and user satisfaction is identified as an object-based attitude. This research model is a new lens for continuance usage research.

Digital natives have become significant users of social network sites (SNSs); therefore, their disclosed personal information can be misused by SNS providers and/or other users. The purpose of this paper is to understand how digital natives make their self-disclosure decisions on SNSs, as well as whether the concept of culture can still be relevant to digital natives.

The hypotheses were tested with survey data collected from the USA and China.

The results show that trust in SNSs and trust in SNS users are positively related to social rewards. Social rewards are positively related to intention to self-disclose, while privacy risk is positively related to privacy concerns. Further, culture significantly moderates the relationship between trust and social rewards.

The study clarifies the effects of different types of trust on privacy in the context of SNSs. Further, the study shows the effects of culture when digital natives make self-disclosure decisions.

SNS providers also need to focus on different types of trust when operating in different cultural contexts. Further, SNS providers expanding their markets should emphasize social rewards to increase the likelihood of self-disclosure.

The results show that while culture can still be helpful to explain digital natives’ trust beliefs, digital natives have started to converge regarding their perceptions about privacy concerns and self-disclosure.

Making decisions on preventive maintenance (PM) policy and buffer sizing, as is often studied, may not result in overall optimization. The purpose of this paper is to propose a joint model that integrates PM and buffer sizing with consideration of quality loss for a degenerating system, which aims to minimize the average operation cost for a finite horizon. The opportunistic maintenance (OM) policy which could increase the output and decrease the cost of the system is also explored.

A joint PM and buffer size model considering quality loss is proposed. In this model, the time-based PM and the condition-based PM are taken on the upstream and the downstream machine, respectively. Further, the OM policy based on the theory of constraints (TOC) is also considered. An iterative search algorithm with Monte Carlo is developed to solve the non-linear model. A case study is conducted to illustrate the performance of the proposed PM policies.

The superiority of the proposed integrated policies compared with the separate PM policy is demonstrated. Effects of the policies are testified. The advantages of the proposed TOC-based OM policy is highlighted in terms of low-cost and high-output.

Few studies have been carried out to integrate decisions on PM and buffer size when taking the quality loss into consideration for degenerating systems. Most PM models treat machines equally ignoring the various roles of them. A more comprehensive and integrated model based on TOC is proposed, accompanied by an iterative search algorithm with Monte Carlo for solving it. An OM policy to further improve the performance of system is also presented.

The purpose of this paper is to investigate the relationship between investors' divergence of opinions and the asset prices of foreign stocks and also examine the effect of home market country-level factors on the influence of divergency of opinions on stock price.

The authors employ panel data estimation with fixed effects to examine the host market response in divergent opinions to the earnings announcements. The paper uses the American Depositary Receipts (ADRs) of 42 countries from 1985 to 2011.

The authors find a negative relationship between differences of opinions and excess quarterly earnings announcement returns, and investors do process information asymmetrically based on good and bad earnings shocks. In addition, the authors find the negative relationship between divergent opinions and excess earnings announcement returns in ADRs is more pronounced in countries with short-sales restrictions, while other home-market country-level factors – the enforcement of insider trading law, legal origin, investor protection and rating on accounting standard – do not influence the relationship between investors' divergency of opinion and stock returns.

This paper is among the first to bring asymmetric effects on convergence in Miller framework and enhance the understanding of price convergence documented in Miller (1977). In addition, this study incorporates home-market country-level factors in explaining the relationship between investors' divergency of opinions and stock returns.

The purpose of this study was the preparation of a poly(styrene-co-maleic anhydride)-g-polyetheramine (SMA-g-PEA) hyperdispersant that reduces the viscosity of the system and improves the colouring intensities of pigments.

PEA of specific quality was dissolved in propylene glycol methyl ether. SMA was then added according to the required mass ratio. The solution was refluxed for 10 h under a stream of protective N2. The prepared hyperdispersant was then characterised by Fourier-transform infrared, UV–visible and ¹H NMR spectroscopies, gel-permeation chromatography and thermogravimetry.

PEA was successfully grafted onto the SMA polymer and the synthesised product was found to be thermally stable. The copolymer with a 6:1 mass ratio is the best dispersant and was used to disperse carbon black, phthalocyanine blue and permanent violet in water-based systems, which helps to improve the application performance of each pigment by reducing the viscosity of the system and improving the colouring intensity of the pigment. The water dispersion is stable and does not exhibit an increase in viscosity after seven days of oven aging at 50°C.

SMA-g-PEA water-based hyperdispersants were successfully synthesised. The prepared hyperdispersants help to improve the application performance of each studied pigment by reducing the viscosity of the system and improving the colouring intensity of the pigment.

The purpose of this paper is to study the microstructure and properties of Sn-3.5Ag and Sn-3.5Ag-0.5Sb lead-free solder alloys with and without a rotating magnetic field (RMF).

Optical microscopy, scanning electron microscopy and X-ray diffraction were used to analyze the effect of an RMF on the microstructure of the solders. Differential scanning calorimetry was used to study the influence of the RMF on the thermal characteristics of the solders. The mechanical properties of the alloys were determined by tensile measurements at different strain rates.

The ß-Sn grains and intermetallic compounds for the Sn-3.5Ag and Sn-3.5Ag-0.5Sb lead-free solder alloys were refined under an RMF, and the morphology of the ß-Sn grains changed from dendritic to equiaxed. The pasty range was significantly reduced under an RMF. The ultimate tensile strength (UTS) of Sn-3.5Ag improved under the RMF, whereas the UTS of Sn-3.5Ag-0.5Sb decreased slightly. The addition of Sb to the Sn-3.5Ag alloy significantly enhanced the UTS and elongation (El.%) of the samples. The UTS of the solder increased with increasing strain rate.

The results revealed that the application of RMF in the molten alloy had a significant effect on its microstructure and mechanical properties. The thermal characteristics of the Sn-3.5Ag and Sn-3.5Ag-0.5Sb solder alloys were improved under the RMF. This research is expected to fill a knowledge gap regarding the behaviour of Sn-Ag solder alloys under RMF.

To increase the use of the meshless method, a hybrid stress method is introduced into the meshless method.

The method is based on the radial point interpolation method (RPIM). According to the Hellinger Reissner principle, stress functions are introduced into the solution procedure. Finite elements are used as background cells for integration. All cells are divided into two types – the H cells, which are around the traction-free circular boundary, and the G cells. For the H cells, stress functions in polar coordinates are created. For the G cells, 12-parameter stress functions in Cartesian coordinates are used. Stress functions are based on equilibrium equations and stress compatible equation.

Numerical results show that this method is reliable.

Hybrid stress methods have been applied to finite element methods, but the finite element methods have not been applied into meshless methods.