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The purpose of this paper is the reliability analysis for systems with dependent gamma degradation process and Weibull failure time.

Consider a life testing experiment in which a sample of n devices starts to operate at t=0 and the data are available on failure time and failure-evolving process on each individual, called in some contents wear or degradation. Ignoring the between performance characteristics dependency structure may lead us to different reliability estimations, while the dependency justly exists. In previous research, dependency between the degradation process and hard failure time has been studied in limited detail (special closed form expression). Thereafter, the dependency between two degradation processes with the same structure (gamma process) in a system is considered using the copula function.

The results indicate that ignoring the dependency structure may lead us to different reliability estimations while the dependency justly exists.

This study gives some contributions that evaluate reliability metrics with more than one failure mechanism that may not be independent and possibly follow a different distribution function. The authors have used the copula function as a basis to develop a proposal model and analysis methods. In addition, the authors discussed the identifiability of the copula. Finally, simulation data were used to review the suggested approach.

This empirical study aims to consider the stability and connection of implicit leadership theories to authentic leadership using performance feedback as a first step in a larger research agenda.

Scenarios were created to operationalize implicit and authentic leadership, manipulate implicit leadership theory between followers and leaders, and discover perceptions of leader effectiveness. The use of scenarios was purposely intended to create anticipatory future research agendas.

Components of authentic leadership may be a part of implicit leadership theory and leadership performance feedback may alter leader and follower implicit leadership theories.

Data collected in this study were from students’ perceptions, and did not infer causality between constructs. This study is also subject to mono‐operation and mono‐method bias.

This research provides an extension of theory in several ways: by looking at the authentic leadership paradigm; and by viewing perceptions of leader authentic effectiveness as a continuous influence on implicit leadership theories.

The authors examine the dependence structure of the BRICS exchange rates.

The authors construct a regular vine copula model to study the co-movements of exchange rates in BRICS controlling the influences from the SDR currencies and the oil prices.

The main findings show that, after the financial crisis, RMB pursued a more balanced strategy shifting from USD-centered to USD-EUR dependency and the oil prices become more dependent on RUB than USD, which could weaken the dollar hegemony. From robustness tests, we find that the inclusion of RMB in SDR has certain but limited impacts on the dependence structure and the influence of the GBP weakened as well. The results have important implications for currency trade, policy design and the future of the BRICS.

The contribution of this paper is twofold. First, we examine the interdependence structure of the BRICS exchange rates controlling for the influence of SDR currencies and the oil prices with R-Vine copula model. Second, we compare the pre- and after-crisis structure and see if the financial crisis and the BRICS summits have changed the structure.

The primary purpose of this study is to unveil the relationship between oil prices and exchange rates, with a specific focus on five major oil-importing countries. By examining this relationship, the research aims to provide valuable insights for policymakers, investors and stakeholders operating in the global economic landscape.

The study employs a methodological approach to ensure robust and reliable findings. First, we assess the stationarity of the time series data to establish a solid analytical foundation. Subsequently, we construct GARCH(1,1) models to capture the persistence of the volatilities inherent in the data. Building upon this, we propose the novel application of the Markov-switching R-vine copula approach, which enables us to capture structural changes and measure the dependencies between oil prices and exchange rates.

Our findings uncover significant negative relationships between oil prices and exchange rates across the examined economies while revealing varying degrees of interdependency among these variables. Notably, we elucidate distinct tail dependence structures, encompassing both symmetric and asymmetric aspects, which hold profound implications for risk assessment and portfolio management strategies. Furthermore, this study confirms the presence of regime-switching dynamics, elucidating how the co-movement patterns between oil prices and exchange rates evolve across different states or regimes, reflecting the dynamic nature of these interconnected markets.

The originality and value of this study lie in its comprehensive approach to understanding the relationship between oil prices and exchange rates. By accounting for structural changes and regime-switching behaviors, the research provides a nuanced understanding of the complex dynamics at play. The novel application of the Markov-switching R-vine copula approach contributes to the methodological advancement in this field of study. Furthermore, the insights derived from this research offer practical implications for policymakers, investors and stakeholders navigating the complexities of the global economic landscape, enabling them to make informed decisions and develop effective strategies to mitigate risks and capitalize on opportunities.

This paper aims to investigate empirically the linkages between stock and commodity futures markets.

It involves the application of a flexible copula approach to weekly total returns from the S&P 500 index and from three commodity sub-indices (agriculture, metals and energy) from 1995 to 2017.

Co-movement is by no means frequent and symmetric. It was predominantly zero before the last financial crisis, and since then, it is positive and asymmetric. The pattern of asymmetry is consistent with transmission of shocks under extreme negative shocks only. Recently, total returns of commodity futures are very poor. At the same time, commodity futures markets move in step (out of step) with stock markets when the latter plunge (rise), pointing to limited diversification benefits. These appear to justify the concerns of investors and researchers whether including commodities in a portfolio of assets is still a prudent investment strategy.

It is the only manuscript that combines a flexible copula approach and co-movement measurement along both the positive and negative diagonals. The findings are in sharp contrast with those reported by Delatte and Lopez (2013) and are very important for portfolio management.

This paper aims to analyze the dependence structure between the Green Sukuk Spread in Malaysia and uncertainty factors from January 1, 2017, to May 23, 2023, covering two main periods: the pre-COVID-19 and the COVID-19 periods.

This study contributes to the current literature by explicitly modeling nonlinear dependencies using the Regular vine copula approach to capture asymmetric characteristics of the tail dependence distribution. This study used the Archimedean copula models: Student’s-t, Gumbel, Gaussian, Clayton, Frank and Joe, which exhibit different tail dependence structures.

The empirical results suggest that Green Sukuk and various uncertainty variables have the strongest co-dependency before and during the COVID-19 crisis. Due to external uncertainties (COVID-19), the results reveal that global factors, such as the Infect-EMV-index and the higher financial stress index, significantly affect the spread of Green Sukuk. Interestingly, in times of COVID-19, its dependence on Green Sukuk and the news sentiment seems to be a symmetric tail dependence with a Student’s-t copula. This result is relevant for hedging strategies, as investors can enhance the performance of their portfolio during the COVID-19 crash period.

This study contributes to a better understanding of the dependency structure between Green Sukuk and uncertainty factors. It is relevant for market participants seeking to improve their risk management for Green Sukuk.

Thorn model psychosocial interventions (PSI) assist clients and their carer systems to manage the effects of psychotic symptoms. PSI has a broad menu of possible interventions from which a client and their therapist choose the most efficacious. In this process, assessment of the client's lived experience is crucial to choosing the most appropriate interventions. However, there are difficulties in adapting interventions designed for the ‘normal’ population for those with learning disabilities. This case study will explore conducting a Thorn model semi‐structured interview with a man with a diagnosis of Asperger's syndrome and mental health problems, highlighting both challenges and the approach used to address them.

The vigilante subgenre represents one of the more problematic trends in American action cinema, as it inherently boasts reactionary sentiments through the promotion of violence as an adequate means of asserting one's masculinity. As will be argued in this chapter, American vigilante films can be categorised into three distinct historical waves: the 1970s, the 2000s and the 2010s. The products of each wave present themes of masculinity relevant to their respective cultural period, specifically, anti-counterculture sentiments, post-9/11 anxieties and a growing cultural awareness of toxic masculinity. The third wave of vigilante films is particularly noteworthy in that it correlates with the prospective emergence of metamodernism, a cultural movement that, in contrast to postmodernism's use of apathy as response to trauma, opts for a cautiously optimistic return to metanarratives. Consequently, third wave vigilante films provide more deconstructive portrayals of vigilante figures through metamodernism's oscillation between irony and optimism. This chapter will outline the history of these three waves of vigilante cinema and provide textual analysis of Blue Ruin (2013) and You Were Never Really Here (2017), two third wave films that demonstrate self-reflexive portrayals of vigilante violence in correlation with metamodern masculinity. The results of these analyses indicate that vigilante films, and perhaps American action cinema in its entirety, are moving towards narratives that seek to challenge the more reactionary sentiments of films from years prior.