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In order to generate electricity from sunlight, spacecraft that operate within the inner solar system often utilize photovoltaic solar panels that are controlled by power electronics. For this purpose, the emerging technologies of perovskite solar cells (PSCs) have attracted plenty of attention recently. Improving the stability of this kind of cell is the main purpose of this research. In the current work, for the first time, dynamic stability analysis of the PSCs, including the multi-directional functionally graded (MD-FG) layer as the host layer, is presented. Also, due to the complex situation of solar cells, this kind of system may be under mechanical shock loading. Various types of PSCs, including cylindrical, spherical, and hyperbolic paraboloid solar cells, by changing curvature factors are modeled. For considering the size-dependency of the PSCs, modified couple stress theory (MCST) with one length scale factor on the strain energy is presented. The forced vibration caused by mechanical shock loading is illustrated by inverting the Laplace transform using the fully modified representation of Abate and Dubner's solution. A deep neural network (DNN) with independent variables, hidden, input, and output layers, intrinsic neural network parameters, activation function, hidden neurons, and loss function is offered to train the current appropriate structure once the results of mathematical modeling have been obtained. Finally, by applying the two-dimensional differential quadrature method (2D-DQM) as an accurate integral operator, the discretized motion equations can be derived from the weak form of the equations. Finally, in the results section, some suggestion for improving the stability and frequency of the PSCs is discussed. [ABSTRACT FROM AUTHOR]

Real-estate prices have soared since the start of the COVID-19 pandemic amid historically low mortgage rates and limited supply. The external shock observed in the real-estate market through relief measures may trigger changes in optimal conservation portfolios. The objective of this research is to identify the impacts of the real-estate market shock triggered by the pandemic through low-interest rates and limited real-estate supply on risk-diversification strategies for land conservation investment and to understand the implications of these impacts. We use a case study involving biodiversity conservation in the central and southern Appalachian region of the US by comparing modern portfolio theory (MPT) outputs using future conservation cost predictions with and without the shock. We find that the financial burden to fund the same level of risk-diversifying conservation benefits increases due to the shock and increases at an increasing rate as the return on investment (ROI) objective rises. This finding is alarming since higher conservation costs triggered by the shock decrease the cost-effectiveness of risk diversification, and this effect exacerbates with the goal of achieving higher ROI. Spatial diversification strategies with and without the shock offer risk-diversification information to help conservation organizations determine effective investment strategies. [ABSTRACT FROM AUTHOR]

This paper explores how the international exposure of companies influenced their strategies in responding to the COVID-19 crisis, and the extent to which they were affected. Our conceptual framework formulates two hypotheses that can be empirically tested. First, we posit that international companies, due to their connections with domestic and foreign markets, are more vulnerable to the crisis, being affected through both demand and supply channels. Second, despite their heightened exposure, we anticipate that international companies will exhibit greater resilience during the crisis compared to their domestic counterparts. This resilience can be attributed to their enhanced global connectivity and productivity. The empirical analysis, based on a large firm-level survey undertaken in 2020 in 133 countries, documents how different types of firms were affected by COVID-19 crisis and how they reacted to the disruptions, providing empirical support for both hypotheses. [ABSTRACT FROM AUTHOR]

In this article, we focus on how the issue strategies of political leaders are influenced by an external shock that completely changes the public agenda of the election campaign. The 2022 Hungarian parliamentary election campaign is a unique case to investigate this question, as Russia attacked Ukraine six weeks before the election day (April 3, 2022). The study aims to investigate whether the campaign's issue strategies changed due to this shocking event, and if so, what are the main directions of the changes. The examination relies on a manual content analysis of Hungarian party leaders' Facebook posts during the campaign, covering both the period before and after the outbreak of the war. First, based on the literature, we distinguish between different issue strategies such as issue ownership, issue stealing, "riding the wave," and multi-issue and issue-poor strategies. We categorize political leaders' issue strategies based on their issue focus before and after the external shock. Our results show that while war, economy, and foreign policy play a greater role in the communication of most political actors after February 24, there are remarkable differences between political actors. The communication of opposition party leaders seems to persist with their original issue strategies (issue-poor and multi-issue campaigns), while Viktor Orbán clearly changed his focus immediately after the invasion of Ukraine and ran a "riding the wave" campaign with a focus on war. [ABSTRACT FROM AUTHOR]

External shocks and policy spillovers have facilitated a gradual shift away from the exceptionalism (exclusive role of agricultural interests) in the EU Common Agricultural Policy (CAP). This article argues that post-Lisbon decision-making rules and procedures, against some of the expectations, slowed this process. First, the parallel veto-based negotiations on the bloc's finances gave status quo actors the opportunity to influence the CAP indirectly (by blocking the redistribution of CAP funds) and directly (through package deals). Second, the co-decision procedure allowed the ministers of agriculture and the European Parliament's Committee of agriculture to change the proposals of the more reform-minded Commission more easily. The argument is supported by the case of the CAP 2023–2027 reform, which resulted in limited changes given the Brexit-related cut in CAP funding (external shock) and the inclusion of environmental targets as part of the European Green Deal (policy spillover effects). [ABSTRACT FROM AUTHOR]

This article examines how public policy, governance and institutional structures have been established and transformed in response to cyberattacks attributed to Russia that focused political attention in Lithuania. It argues that, despite the growing number of cyberattacks, political and institutional change has initially been slow and it has taken a decade to establish an adequate legal and institutional framework. The reasons for such a slow change are analysed, highlighting limited capacity (lack of understanding of cybersecurity by policy-makers and the lack of attention and other resources allocated to it), institutional fragmentation and coordination problems. It was only after Russia's aggression against Ukraine in 2014 that cybersecurity policy started to be seen through the prism of national security and parliamentary elections created a window of opportunity for change, which resulted in significant policy transformation in 2017–2018. Interestingly, since then it remained relatively stable, even after Russia's large scale war against Ukraine in 2022, which had only led to operational cybersecurity policy changes in Lithuania. The article contributes to the debates on the role of external shocks on policy change and the mediating factors which can slow down or facilitate change. [ABSTRACT FROM AUTHOR]

This article examines the effect of firm product similarity on stock price comovement. Using the financial data and annual reports of listed firms in the Chinese A-share market from January 2001 to December 2021, we find that firms with greater product similarity experience synchronized movements in their stock prices. This effect is driven by firm fundamentals, as demonstrated through major international events (Global Financial Crisis, European Sovereign Debt Crisis, and Trade Dispute between China and the U.S.) and domestic events (Two Sessions about the Deepening Overall Reform, and Central Economic Conference following the COVID-19 Outbreak). We also show that firms that release earnings announcements earlier contribute to the comovement of stock prices within their product-similarity cluster. Our findings are robust across various tests and provide insights into the dynamics of the Chinese A-share market. [ABSTRACT FROM AUTHOR]

In this article, we focus on how the issue strategies of political leaders are influenced by an external shock that completely changes the public agenda of the election campaign. The 2022 Hungarian parliamentary election campaign is a unique case to investigate this question, as Russia attacked Ukraine six weeks before the election day (April 3, 2022). The study aims to investigate whether the campaign’s issue strategies changed due to this shocking event, and if so, what are the main directions of the changes. The examination relies on a manual content analysis of Hungarian party leaders’ Facebook posts during the campaign, covering both the period before and after the outbreak of the war. First, based on the literature, we distinguish between different issue strategies such as issue ownership, issue stealing, “riding the wave,” and multi-issue and issue-poor strategies. We categorize political leaders’ issue strategies based on their issue focus before and after the external shock. Our results show that while war, economy, and foreign policy play a greater role in the communication of most political actors after February 24, there are remarkable differences between political actors. The communication of opposition party leaders seems to persist with their original issue strategies (issue-poor and multi-issue campaigns), while Viktor Orbán clearly changed his focus immediately after the invasion of Ukraine and ran a “riding the wave” campaign with a focus on war.

In fields such as aerospace and nuclear materials, there is no large amount of sample data available for reference due to cost and experimental environment; probabilistic theory based on large sample data is not suitable for assessing the reliability of equipment. Due to the lack of a large amount of failure data, the reliability assessment of the equipment has to rely on the empirical data of experts in the field, which have artificial cognitive uncertainty, and uncertainty theory is an effective mathematical tool to analyze the artificial cognitive data. In the uncertain environment, this paper considers the competing failure processes where the failure threshold is an uncertain variable, calculates the reliability of the device under three different shock models, and compares the reliability of the uncertain thresholds with the reliability of the constant thresholds. The results show that in different periods of equipment operation, the reliability of the uncertain thresholds is different with the reliability of the constant thresholds. If the threshold is simply regarded as a known constant, it will cause inaccuracies in the reliability assessment of the system, miss the best maintenance time, and cause unnecessary losses. Taking the microelectronic mechanical system as an example, the superiority of the proposed model is illustrated. [ABSTRACT FROM AUTHOR]

This study investigates two aspects of how an external shock in the guise of the Covid-19 pandemic affects domestic tourism demand: (1) If the impact varies across regions and over time or (2) whether a permanent change (hysteresis) occurs anywhere. By doing so, a presumptive change in domestic tourism demand during three summers is quantified based on timely official data for all Nordic countries (Denmark, Finland, Iceland, Norway and Sweden) and Estonia, encompassing a total of 76 NUTS3 regions. These regions are divided into five groups from large metropolitan to remote. Tourism demand is approximated by the number of domestic overnight stays in accommodation establishments in the summer months 2016–2022. Dynamic panel data estimations, including household consumption and hotel price index, reveal that all non-metropolitan regions experience a strong increase in domestic tourism flows in the first summer of the pandemic compared with the three years preceding 2020. In contrast, the largest metropolitan areas encounter a substantial decline. The surge in demand for non-metropolitan areas continues in 2021, while the large metropolitan regions return to their pre-pandemic level. After this, demand no longer deviates from its pre-2020 pattern across regions, confirming that the effects are temporary. [ABSTRACT FROM AUTHOR]

Modeling the effects and paths of systemic financial risk contagion is significant for financial stability. This paper focuses on China's systemic financial risk from the perspective of dynamic networks. First, we construct a high-dimensional dynamic financial network model to capture risk contagion effects. Second, considering the ripple effect of financial risk contagion, we introduce and improve the basic model of the ripple-spreading network. Finally, small- and medium-sized banks and economic policy uncertainty are selected as the internal and external contagion source, respectively, to simulate the risk of ripple-spreading paths. The results show that financial contagion is more likely to occur within the same industry. The contagion triggered by internal shock first spreads within the same industry, and then to other industries. The contagion triggered by external shock first spreads to banks, then to diversified financial institutions, securities and insurance institutions, successively. Moreover, some small- and medium-sized commercial banks show strong abilities to spread risk ripples. The securities industry is the intermediary layer of the ripple network and plays a leading role in the ripple-spreading process. Therefore, systemic financial risk regulation should focus not only on large financial institutions but also on financial institutions with strong ripple effects. During major risk events, isolating risk intermediary nodes can cut off the paths of risk contagion and mitigate the impact on the whole financial system effectively. [ABSTRACT FROM AUTHOR]

This study assesses the impact of external shocks on select small open economies (SOEs) using the Bayesian variant of the global vector autoregression model with time varying parameters and stochastic volatility. We account for the curse of dimensionality in the multi-country VAR system by implementing three different priors in the estimation of the parameters of the model: the Minnesota (M-N) prior of Doan–Litterman et al. (1984; Litterman 1986); the Normal-Gamma (N-G) prior of Park and Casella (Bayesian Anal 1:515–533, 2008); and the Stochastic Search Variable Selection (SSVS) prior of George and McCulloch (1995) as extended by Koop and Korobilis (2010, 2013). From our simulation results, we found that global economies of the USA, Western Europe and China are the major drivers of cyclical fluctuation in the SOEs. However, in spite of the perceived superior influence of China on the SOEs GDPs' response to external shocks, we found no evidence to conclude that the influence is significantly greater than those exerted by the United States or Europe on the bloc's economies. [ABSTRACT FROM AUTHOR]

Purpose – This study aims to investigate the influences of global uncertainty indicators volatility on the domestic socioeconomic and environmental vulnerability in a sample of 54 developing countries. Design/methodology/approach – The two-step system generalized method of moments estimator is recruited to deal with autoregression and endogeneity matter in our dynamic panel data. Seven different global uncertainty indicators (US trade uncertainty; world trade uncertainty; economic policy uncertainty; world commodities and oil prices; the geopolitical risk index and the world uncertainty index) have been mobilized and compared for their empirical impact on the economic (growth and GDP), social (the misery index and income inequality) and environmental (CO2 emissions) vulnerabilities of nations. Findings – Our empirical estimations suggest that the socioeconomic and environmental vulnerability cannot be solved through the same pattern: all decrease of a particular aspect will necessarily have a cost and an opposite influence on at least one of the other aspects of the nations' vulnerability. Originality/value – The originality of this article is to combine these three dimensions of vulnerability in the same investigation. To our knowledge, our research is one of the few providing a joint analysis of the influence of global uncertainty on the economic and socioenvironmental countries' vulnerabilities – given the fact social, economic and environmental aspects are at the heart of the UN sustainable goals, our study can be seen as an investigation of the nations' capabilities to work proactively on meaningful sustainable goals in an increasingly uncertain world.

The research aims to prioritize the pandemic's impact on the financial markets of developed and developing economies using a multi-criteria decision-making approach. The results revealed that COVID-19's pandemic effects on financial markets differ between developed and developing nations. COVID-19 pandemic affects developed countries' financial markets more through supply reduction, demand reduction, and economic instability. Regarding developing nations, confidence and expectations, changes in consumption patterns, and the bandwagon effect are the three most significant impacts of COVID-19 pandemic on financial markets. The best decisions to lower the effect of COVID-19 pandemic on developed nations' financial markets are the declaration of the stimulus package and support of small-and-medium-sized enterprises. Contrastingly, in developing countries, support for vulnerable households and declaration of the stimulus package are the best decisions to combat COVID-19's negative impact on their financial markets. As practical policy implications for lowering COVID-19's negative impact on financial markets, the promotion of new financing instruments, reconstruction of the relationship between public and private sectors, and support of vulnerable households and enterprises are highly recommended. [ABSTRACT FROM AUTHOR]

• A set of indices are constructed to measure electric vehicle (EV) market resilience. • A conceptual framework is proposed to explore contributors to EV market resilience. • China's provincial EV market resilience and underlying contributors are investigated. • China's EV market resilience presents regional heterogeneity and spatial agglomeration. • Key contributors to China's provincial EV market resilience are identified. This study assesses electric vehicle (EV) market resilience and explores its underlying contributors. We develop a set of indices to measure the resistance, recoverability, and comprehensive resilience of the EV market. A four-dimensional conceptual framework, encompassing market foundation, industrial foundation, policy support and usage environment, is proposed to investigate the potential contributors to the EV market resilience. The models are applied to China's provincial EV markets, and the geographical detector model is used for empirical investigation. We identify an imbalanced distribution of regional EV market resilience, characterized by a spatial clustering of high-performing regions. Notably, a majority of regions encounter challenges in simultaneously achieving high performance in both resistance and recoverability. It is found that contributors across the conceptual framework exhibit varying degrees of influence on resilience, with resistance shaped by inherent factors and recoverability by agency-based factors. However, diverse initiatives may counteract each other, due to interactions among contributors. [ABSTRACT FROM AUTHOR]

This paper empirically investigates the impact of technology-seeking outward foreign direct investment (OFDI) on firms' productivity under the influence of negative external shocks, taking as a sample the investment data of Chinese firms before and during COVID-19. The results show that technology-seeking OFDI improves productivity, but not under negative external shocks. The dampening effect of such shocks is more significant when the host country is a developed country and in firms with multiple branches. Technology-seeking OFDI particularly improves the productivity of research and development and processing firms, and (among the productivity measures tested) most prominently affects total factor productivity., (© 2021 Elsevier Inc. All rights reserved.)