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Nowadays, the breakout of the COVID-19 pandemic has caused an important change in teaching models. The emotional experience of this change has an important impact on online teaching. This paper aims to explore its time evolution characteristics and provide reference for the development of online teaching in the post epidemic era.

The article firstly crawls the online teaching-related comment text data on Zhihu platform and performs emotional calculation to obtain a one-dimensional time series of daily average emotional values. Then, by using non-linear time-series analysis, this paper reconstructs the daily average emotion value time series in high-dimensional phase space, calculates the maximum Lyapunov exponent and correlation dimension and finally, explores the feature patterns through recurrence plot and recurrence quantification analysis.

It was found that the sequence has typical non-linear chaotic characteristics; its correlation dimension indicates that it contains obvious fractal characteristics; the public emotional evolution shows a cyclical rise and fall. By text mining and temporal evolution analysis, this paper explores the evolution law over chronically of the daily average emotion value time series, provides feasible strategies to improve students' online learning experience and quality and continuously optimizes this new teaching model in the era of pandemic.

Based on social knowledge sharing platform of Q&A, this paper models and analyzes users interaction data under online teaching-related topics. This paper explores the evolution law over a long time period of the daily average emotion value time series using text mining and temporal evolution analysis. It then offers workable solutions to enhance the quality and experience of students' online learning, and it continuously improves this new teaching model in the age of pandemics.

Drawing from cognitive and emotional perspectives, the purpose of this paper is to theorize and test a dual-pathway model in which moral disengagement and anger toward organization act as two explanatory mechanisms of the association between perceived overqualification and employee cyberloafing. The authors further proposed that the strengths of these two mediating mechanisms depend on employee moral identity.

The authors used hierarchical linear modeling to examine the hypotheses by analyzing a sample of 294 employees working in 71 departments in China.

Results revealed that moral disengagement and anger toward organization mediated the positive link between perceived overqualification and cyberloafing beyond the influence of social exchange. Furthermore, moral identity attenuated the association between the mediators (i.e. moral disengagement and anger) and cyberloafing and the indirect relationship between perceived overqualification and cyberloafing.

Extant studies have examined the effects of perceived overqualification on employee behaviors in terms of task performance, organizational citizenship behavior, proactive behavior, as well as withdrawal behavior. The study expands this line of research by empirically investigating whether and how perceived overqualification influences cyberloafing.

This paper investigates the impact of the development of capital markets on economic growth in Africa and reports a significant increase in real GDP per capita after stock exchanges are established. This paper also reveals that there are significant improvements in the level of private investments in the post stock market launch era. The results also indicate that stock markets play a complementary role to the banking sector by contributing to the availability of private credit. Although African capital markets are relatively less advanced when compared to capital markets on other continents (particularly in terms of technology, structure, and liquidity), we find that their establishment has been crucial in helping African countries catch up with the rest of the world.

The purpose of this paper is to study the general actuator modeling in spacecraft attitude control systems.

The proposed module in this paper provides various non-ideal factors such as the second-order dynamic time response, time-delay, bias torques, dead-zones and saturation. The actuator module can make the simulation as close to the practical situation as possible.

This paper presents a practical integrated module for the simulation of attitude control algorithms. Based on theoretical modeling, we give simulation modules and numerical examples. The proposed model can be directly used in spacecraft control simulation. Instead of considering only a few of them, it makes the simulation more convincing. Though it may not be perfect, it is better than totally ignoring the actuator dynamics.

The authors provide an integrated actuator model for spacecraft attitude control simulation, considering as many nonlinear factors as possible once time.

The study aims to examine the export-led growth (ELG) hypothesis for Bangladesh. The direction of causality between export and output largely determines the success of export-oriented trade policies. A unidirectional causality running from export to output growth is required according to the narrow definition, while bidirectional causality is allowed for the broader definition. The study offers the causality inference, both from narrow and broader senses.

The study uses the bootstrap version of Toda and Yamamoto-modified causality tests, a recent development in time series econometrics, robust against the regularity conditions such as stationarity, properties of integration and cointegration and constancy of parameters. It uses monthly secondary data for the period of 1990-2014.

Test results suggest a unidirectional positive causal relationship from exports to output growth, meaning that the policies and strategies supporting exports are promoting output growth and thereby approve the ELG hypothesis for Bangladesh from the narrow sense. However, the absence of bidirectional causality between export and output growth, necessary to support the ELG hypothesis from the broader perspective, discards the conjecture that output growth is reinvigorated through the probable second-round effects of ELG produced from output growth to exports.

Lower investments in infrastructure, technology and education are reasons for the absence of ELG from the broader sense. Therefore, directing returns generated from exports for the development of technology, infrastructure and human capital, with regular and continuous revision of trade-liberalization policies so as to make its exports more competitive in the world market, will help Bangladesh trigger the second-round effect of ELG produced from output growth to exports.

Beyond the conventional approaches, this is the first contemporary time series econometrics causality analysis between export and output growth of Bangladesh, both from narrow and broader senses.

Recent spacecraft attitude control systems tend to use wireless communication for cost-saving and distributed mission purposes while encountering limited communication resources and data exposure issues. This paper aims to study the attitude control problem with low communication frequency under the sampled-data.

The authors propose constructive control system structures based on quantization and event-triggered methods for intra-spacecraft and multi-spacecraft systems, and they also provide potential solutions to shield the control system's data security. The proposed control architectures can effectively save communication resources for both intra-spacecraft and multi-spacecraft systems.

The proposed control architectures no longer require sensors with trigger-ing mechanism and can achieve distributed control schemes. This paper also provides proposals of employing the public key encryption to secure the data in control-loop, which is transmitted by the event-triggered control mechanism.

Spacecraft attempts to use wireless communication, yet the attitude control system does not follow up promptly to accommodate these variations. Compared with existing approaches, the proposed control structures can save communication resources of control-loop in multi-sections effectively, and systematically, by rationally configuring the location of quantization and event-triggered mechanisms.

This paper presents several new control schemes and a necessary condition for the employment of encryption algorithms for control systems based on event-based communication.

The purpose of this paper is to investigate the export‐led growth, growth‐led export, import‐led growth, growth‐led import and foreign deficit sustainability hypothesis in the case of China, using annual time series data from 1978‐2009.

For estimation evidence this study employs the Phillips Perron unit root tests to examine the level of integration and the autoregressive distributed lag (ARDL) approach is employed to determine the long run relationship, and the direction of long run and short run causal relationship is examined by using modified Granger causality test.

The results confirm the bidirectional long run relationship between the economic growth and exports, economic growth and imports, and exports and imports. These findings guided the authors to conclude that the exports‐led growth, growth‐led exports, imports‐led growth and growth‐led imports hypothesis is valid, and foreign deficit is sustainable for China. The long run elasticities are as follows: the elasticity of economic growth with respect to exports is 0.591, and elasticity of exports with respect to economic growth is 1.635. The elasticity of economic growth with respect to imports is 0.621, and elasticity of imports with respect to economic growth is 1.392. Further more the elasticity of exports with respect to imports is 1.322, and imports elasticity with respect to exports is 0.975.

This study utilizes the relative new cointegration method of ARDL approach. The empirical findings of this study are vital for policy makers of China in the formulation of trade policies.

This paper aims to study the attitude control problem with mutating orbital rate and actuator fading.

To avoid malicious physical attacks and hide itself, the spacecraft may irregularly switch its orbit altitude within a specific range, which will bring about variations in orbital rate, thereby causing mutations in the attitude dynamics model. The actuator faults will also cause changes in system dynamics. Both factors affect the control performance. First, this paper determines the potential switching orbits. Then under different conditions, design controllers that can accommodate actuator faults according to the statistical law of actuator fading.

This paper, to the best of the authors’ knowledge, for the first time, introduces the Markovian jump framework to model the possible unexpected mutating of orbital rate and actuator fading of spacecraft and then designs a novel control policy to solve the attitude control problem.

This paper also provides the algorithm design processes in detail. A comparative numerical simulation is given to verify the effectiveness of the proposed algorithm.

This is an early solution for spacecraft attitude control with dynamics model mutations.

This study aims to decrypt the efforts made by Chinese people's courts nationwide to protect the rights of Chinese posted workers in the Belt & Road (B&R) countries by investigating labour litigation cases with an extraterritorial application of Chinese labour law (under the “doctrine of overriding mandatory labour rules”).

This study collected all labour litigation from 2014 to 2018 brought forward by Chinese posted workers in Chinese courts against Chinese enterprises regarding the performance of employment contracts in the B&R countries where Chinese labour laws were mandatorily applied under the doctrine of overriding mandatory labour rules. The study adopted a qualitive research approach to analyse the compiled cases to explore their characteristics and effects.

This study found that the volume of labour disputes in the B&R countries had a somewhat positive correlation to the amount of investment from China. However, this correlation was rather superficial when compared with the correlation to the type of industrial sector (e.g. the construction sector) and to the claim category (e.g. remuneration claims). Moreover, labour disputes in both the B&R countries and China shared a great deal of similarity with regard to their concentration in certain sectors and in certain types of claims. Therefore, mandatorily applying Chinese labour law could be convenient for Chinese workers returning from abroad who seek remedies and could allow Chinese judges to issue affirmative decisions regardless of the territory in which the worker was posted.

The cases collected by this study were limited to those filed in China by Chinese workers who were hired by Chinese enterprises and sent to work in the B&R countries and did not include those filed in the B&R countries by Chinese posted workers. Future research should therefore attempt to gather a broader range of labour disputes to further clarify the issues and need for labour protection for Chinese posted workers in the B&R countries.

This study argues that the doctrine of overriding mandatory labour rules is not entirely unproblematic because it might arbitrarily rule out the standards set by foreign labour legislation that could be more favourable to workers or offer them greater protection. Therefore, giving judges a certain degree of discretion is imperative to allow them to apply foreign labour standards when they have been proven to benefit workers.

Apart from a handful of reports on individual cases, there have been very few empirical studies regarding the general picture of labour protection for Chinese posted workers in the B&R countries. This study has adopted a novel approach to collect information on labour disputes in the B&R countries and to facilitate a qualitative analysis to test the practical implications of the doctrine of overriding mandatory labour rules.