University of Piraeus
  • Piraeus, Greece
Recent publications
Given the impact of the COVID-19 pandemic on the European real economy, European banks are likely expected to be confronted by a wave of non-performing loans. Focusing on a sample of large banks in the EU area over the pre and during the COVID-19 pandemic period, the analysis shows an extended degree of divergence during the pandemic crisis, with GDP, bank profitability and risk being held the responsible factors. The findings imply that potential plans to deal with NPLs should explicitly consider strategies running from bank restructuring and resolutions to recapitalisation or any other rescue measures.
This paper implements a context-based text mining approach in online reviews of three European historic city districts, to assess the data-driven projection of experiences and major determinants of traveler satisfaction. Bivariate analyses, semantic networks of experience concepts, and word association statistics are used. Results are interpreted in contrast to experience deterioration issues caused by the loss of authenticity, as argued by recent literature. Overtourism signs are a powerful determinant of unfavorable evaluations, but images formed by reviewers are predominantly positive. Nonetheless, although references to authenticity and local identity are not common, destinations failing to project non-touristified aspects are less favored. Overall, evaluations are driven by gratification from offered products and services, as well as passive esthetic consumption of surroundings.
Accurate prediction of Public Transport (PT) mobility is important for intelligent transportation. Nowadays, mobility data have become increasingly available with the General Transit Feed Specification (GTFS) being the format for PT agencies to disseminate such data. Estimated Time of Arrival (ETA) of PT is crucial for the public, as well as the PT agency for logistics, route-optimization, maintenance, etc. However, prediction of PT-ETA is a challenging task, due to the complex and non-stationary urban traffic. This work introduces a novel data-driven approach for predicting PT-ETA based on RBF neural networks, using a modified version of the successful PSO-NSFM algorithm for training. Additionally, a novel pre-processing pipeline (CR-GTFS) is designed for cleansing and reconstructing the GTFS data. The combination of PSO-NSFM and CR-GTFS introduces a complete framework for predicting PT-ETA accurately with real-world data feeds. Experiments on GTFS data verify the proposed approach, outperforming state-of-the-art in prediction accuracy and computational times.
This study examines the impact of environmental, social, and governance (ESG) reputational risk on a sample of listed firms’ market longevity. Using a novel panel dataset consisting of US firms over the period 2007–2019, we perform dynamic empirical analysis to quantify the underlying relationships between firms’ ESG reputational risk and market longevity. We argue that ESG reputational risk has a negative impact on firm growth opportunities, mitigating thus market longevity. The empirical findings survive several robustness checks, providing useful managerial implications for stakeholders and market participants..
The impact of the Covid-19 pandemic on the shipping industry is still severe, ranging from vessels being denied entrance to ports to crews on board ships being trapped for many months. To counter and regulate those emerging issues, the shipping industry presently incorporated into the charter parties the BIMCO’s Disease Clause originated from the 2015 Ebola outbreak, the so-called BIMCO’s Infectious or Contagious Diseases (IOCD) Clauses. While proved successful during the Ebola outbreak, those Clauses were inadequate to regulate a global pandemic such as Covid-19 effectively. Specifically, the IOCD Clauses, while they successfully establish the concepts of ‘Disease’ and ‘Affected Area’, fail with the allocation of liability, especially when the crew on board is affected by Covid-19 and the ship needs to deviate from course to change the crew. In that instance, the shipowner, provided that he exercised due diligence in proactively avoiding the infection of his crew, is excluded from liability. In contrast, it is deemed that the liability between shipowner and charterer should be at least shared. For voyage charter parties BIMCO’s Infectious or Contagious Diseases Clause 2015, applied both to the Ebola and the Covid-19 outbreak, allocates the right of termination and the liability for deviations and excessive costs strictly to charterers. In contrast, for the time charter parties, BIMCO has imposed the ‘BIMCO Infectious or Contagious Diseases Clause for Time Charter Parties 2022′ amended presently. According to those regulations, the liability can and should be shared between charterers and ship owners. As a result, the shipowner is forced to exercise due diligence more effectively, especially when he is initially liable for the excessive costs.
In the present paper a family of discrete distributions is introduced through the probability generating function of any discrete distribution (generator). The properties of the family are systematically studied when the generator belongs to well-known families of discrete distributions (power series distributions, Bernoulli mixtures, Panjer family, Phase-type distributions). Applications are also provided in problems arising from the areas of reliability theory and start-up demonstration testing, which highlight the beneficial use of the family in order statistics related models.
To achieve the European Union's target for climate neutrality by 2050 reduced energy demand will make the transition process faster and cheaper. The role of policies that support energy efficiency measures and demand-side management practices will be critical and to ensure that energy demand models are relevant to policymakers and other end-users, understanding how to further improve the models and whether they are tailored to user needs to support efficient decision-making processes is crucial. So far though, no scientific studies have examined the key user needs for energy demand modelling in the context of the climate neutrality targets. In this article we address this gap using a multi-method approach based on empirical and desk research. Through survey and stakeholder meetings and workshops we identify user needs of different stakeholder groups, and we highlight the direction in which energy demand models need to be improved to be relevant to their users. Through a detailed review of existing energy demand models, we provide a full understanding of the key characteristics and capabilities of existing tools, and we identify their limitations and gaps. Our findings show that classical demand-related questions remain important to model users, while most of the existing models can answer these questions. Furthermore, we show that some of the user needs related to sectoral demand modelling, dictated by the latest policy developments, are under-researched and are not addressed by existing tools.
Malware authors continuously evolve their code base to include counter-analysis methods that can significantly hinder their detection and blocking. While malware execution in a sandboxed environment may provide insightful feedback about what the malware does in a machine, anti-virtualisation and hooking evasion methods may allow malware to bypass such detection methods. The main objective of this work is to complement sandbox execution with the use of binary emulation frameworks. The core idea is to exploit the fact that binary emulation frameworks may test samples quicker than a sandbox environment as they do not need to open a whole new virtual machine to execute the binary. While with this approach we lose the granularity of the data collected through a sandbox, one may only need to efficiently determine whether a file is malicious or to which malware family it belongs. To this end, we record the performed API calls and use them to explore the efficacy of using them as features for binary and multiclass classification. Our extensive experiments with real-world malware illustrate that this approach is very accurate, achieving state-of-the art outcomes with a statistically robust set of classification experiments while simultaneously having a relatively low computational overhead compared to traditional sandbox approaches. In fact, we compare the binary analysis results with a commercial sandbox, and our classification outperforms it at the expense of the fine-grained results that a sandbox provides.
The voluminous empirical research on the effect of financial development on income inequality has yielded mixed results. In this paper, we collect 2127 estimates reported in 116 published studies that investigate the effect of financial development on income inequality. Although our initial tests for publication bias (which do not account for moderator variables) show that the current literature does not suffer from publication selectivity, once we control for a set of moderator variables, we find evidence of mild publication bias in favor of positive estimates (i.e., the current literature favors the publication of studies that find that financial development increases income inequality). In addition, our results suggest that the overall effect of financial development on income inequality is on average zero, but that its sign and magnitude depend systematically on various study characteristics. The characteristics of data and estimation methods, whether endogeneity is taken into account, the different measures of financial development and the inclusion of financial openness, inflation and income variables in the regressions matter significantly for the effect of financial development on inequality.
This chapter studies the historical case of Themistocles to contradict the current “structural orthodoxy” that regards leaders as either theoretically immeasurable or heavily conditioned actors that lack transformative agency. Specifically, we use the case of Themistocles to illustrate six interrelated causal mechanisms that lucidly link both leadership and strategic agency to international outcomes. We argue that leaders may indeed have a consequential and measurable impact upon strategic issues, such as the diagnosis of national threats, the generation of domestic power resources, military organization and reform, alliance formation and alliance management, the outcome of wars, and ultimately the very distribution of power in the international system. As Themistocles’ case study provides both a hard test and an extreme test regarding the impact of leadership upon strategy, it demonstrates quite paradigmatically that leadership can generate power, affect power differentials among states, and ultimately reshape the international balance of power—that is, change the very polarity of the international system. We hope that a structured, analytical study of Themistoclean leadership will not only demonstrate the historical pivotal contributions of Themistocles to the salvation of Greece and the Occident, but also “bring leadership back in” to the study of international politics and help drive a new and rigorous “leadership-centric” theoretical investigation in the discipline.
In this book, well-renowned international scholars discuss topics relating to various aspects of the history of the Battle of Salamis, drawing inspiration from the democratic origins of the great Greek naval victory at Salamis. They present deductions and insights from the battle that can be useful for today, guided by the higher goal of seeking answers for a more prosperous and brighter future for our societies. The book divides their analyses into five parts: (1) The democratic implications of the Battle of Salamis; (2) The strategies that lead to monumental naval victories; (3) The institutional implications of the Battle of Salamis; (4) Various societal aspects of the Athenian democracy; (5) The interconnections between two glorious battles: Thermopylae and Salamis. This book is the first of two edited volumes, both serving as sequels to an international academic conference titled Salamis and Democracy: 2500 Years After that occurred between October 3rd and October 5th, 2020, on the occasion of the 2500th anniversary of the great historical event of the Battle of Salamis, which saved Greek culture and the newly founded democratic regimes throughout the Hellenic world during the Classical period (508–323 BCE).
We explore the relationship between Federal Home Loan Bank (FHLB) advances and systemic risk. In terms of theoretical framework, there exist two links which characterise this relationship. The first connection is from lagged systemic risk to subsequent advances, establishing the ‘liquidity provision’ effect. The second is from lagged advances to subsequent systemic risk, establishing ‘the moral hazard’ effect. We empirically explore which link prevails in the U.S. commercial banking sector, using a unified mixed frequency VAR econometric model. This approach is flexible enough to model quarterly advances and monthly systemic risk. We reveal robust evidence for the link from lagged systemic risk to subsequent advances, thereby supporting the liquidity effect. In addition, we show that this effect is a mechanism which alleviates any detrimental impact of systemic risk on real economic activity. The latter finding carries important policy implications, highlighting the role of FHLB advances in managing the effects of increasing systemic risk on the real economy.
Events can play a critical role in implementing sustainable developing models at destinations. Furthermore, the perceptions of stakeholders may contribute to the sustainability of a tourist destination in the long term. This paper presents an insight into the stakeholders' perceptions of the importance of festival events in promoting tourism sustainability, concentrating on Patras' Carnival. Festivals can be an instrument for tourism development, city image improvement and boosting regional economies. Based on a theoretical model that is grounded in the social exchange theory the research enriches the existing knowledge on promoting sustainable events and sustainable approaches to tourism development by taking into account the views of the leading players of tourism, local residents and business owners. A quantitative survey via a structured questionnaire was conducted in the city of Patras, Greece's third-largest city before the COVID-19 pandemic outbreak. The questionnaire was distributed to the residents and business owners during the Patras' Carnival (Patrino Carnavali), the largest event of its kind in Greece. In total, 238 people participated in the study. It will be presented as a variety of positive and negative impacts of tourism toward economy, society, culture and environment and shed light on adequate managerial practices that boost further tourism flows in cities. The results may be useful not only to local government entities involved in the tourism strategic planning but also to stakeholders engaged in creating sustainable competitive advantage in the tourism industry.
This study focuses on the automation of terminal equipment used to handle containers. A dataset was compiled, which includes 63 fully and semi-automated container terminals in operation around the world, their organizational features, technical dimensions, and the maritime and urban markets they serve. The data analysis focuses on where, when, under which conditions, and to what extent container terminals were automated, and who is responsible for implementing terminal automation. Only 3% of the world’s container terminals were found to be either fully or semi-automated. A survey-based analysis of global terminal operators identifies how they implement their automation and the time necessary for terminal operators to start realizing a return on their investment. The results systematically map global automated terminal characteristics. Acknowledging that not all container terminals are candidates for automation of terminal equipment, this paper contributes to extant literature by presenting a systematic review of all global automated terminals in order to substantiate or refute any perceptions that might exist on their characteristics, for example, in terms of minimum cargo volumes needed for automation. The findings can provide some guidance to market actors considering investments in automation and public and private port authority decision makers that might also commit resources to automation.
Background: Inadequate staffing, increased responsibilities and a high workload are some of the factors that are directly related to stress levels experienced by pharmacists, which in turn affect job satisfaction. Objective: The aim of this study was to assess job satisfaction and stress levels of pharmacists in Cyprus, involving those working in the public and private sector. Materials and Methods: A cross-sectional study was performed which involved the completion of the Job Satisfaction Survey (JSS) questionnaire to estimate job satisfaction, and the Perceived Stress Scale-14 (PSS-14) questionnaire to evaluate perceived stress. Data collection took place between January and March 2020 and the participation rate was 71.6% (n = 585). Results: Employees in private pharmacies overall reported higher levels of job satisfaction compared to public sector pharmacists. Public sector pharmacists were found to have stronger self-efficacy beliefs compared to other groups (p < 0.001). Female pharmacists had a higher average level of perceived helplessness than male pharmacists (p = 0.001). Regarding public sector pharmacists, it was generally observed that pharmacists working under the management of the Ministry of Health (MoH) had reduced job satisfaction than those working for other organizations. Additionally, pharmacists working under the management of the State Health Services Organization (SHSO) had the least overall perceived stress levels (p = 0.008), high self-efficacy beliefs (p = 0.006) and low perceived helplessness (p = 0.031) compared to pharmacists in other workplaces. Employees of private pharmacies were found to have higher levels of job satisfaction (p < 0.001) than SHSO pharmacists. However, those employees demonstrated increased perceived stress levels (p < 0.001) in comparison with SHSO pharmacists. Conclusions: Pharmacists’ job satisfaction is negatively correlated with perceived stress levels and helplessness, and positively correlated with self-efficacy beliefs. In the public sector, it seems that a re-evaluation is critical regarding the determinants that adversely influence job satisfaction amongst pharmacists.
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1,140 members
Andreas Menychtas
  • Department of Digital Systems
Takis Papaioannou
  • Department of Statistics and Insurance Science
Ioannis Theotokas
  • Department of Maritime Studies
Piraeus, Greece