University of Piraeus

About: University of Piraeus is a education organization based out in Piraeus, Attiki, Greece. It is known for research contribution in the topics: Context (language use) & Computer science. The organization has 1731 authors who have published 6209 publications receiving 106699 citations.

Quantile Regression Analysis of Hedge Fund Strategies

Abstract: Extending previous work on hedge fund pricing, this paper introduces the idea of modelling the conditional quantiles of hedge fund returns using a set of risk factors. Quantile regression analysis provides a way of understanding how the relationship between hedge fund returns and risk factors changes across the distribution of conditional returns. We propose a Bayesian approach to model comparison which provides posterior probabilities for different risk factor models. The most relevant risk factors are identified for different quantiles and compared with those obtained for the conditional expectation model. We find evidence of model uncertainty in quantile regression models and evidence that different risk factors affect differently the tails of the distribution of hedge fund returns. We explore potential economic impacts of our approach by analysing hedge fund strategies return series and by constructing style portfolios.

The Electricity Consumption-Growth Nexus: Renewable Versus Non-Renewable Electricity in Central America

Abstract: This study investigates the Granger-causal relationship between renewable and non-renewable electricity consumption and economic growth in the case of Central America within a panel error correction model framework. Larsson et al. (2001) panel cointegration test reveals a long-run equilibrium relationship between real gross domestic product, renewable electricity consumption, non-renewable electricity consumption, real gross fixed capital formation, and the labor force. With the exception of renewable electricity consumption, the respective long-run coefficient estimates are positive and statistically significant. The results from the panel error correction model indicate unidirectional causality from renewable electricity consumption to economic growth in the short-run, but bidirectional causality in the long-run. The results also indicate bidirectional causality between non-renewable electricity consumption and economic growth in both the short-run and long-run.

Security in IoMT Communications: A Survey

Abstract: The Internet of Medical Things (IoMT) couples IoT technologies with healthcare services in order to support real-time, remote patient monitoring and treatment. However, the interconnectivity of critical medical devices with other systems in various network layers creates new opportunities for remote adversaries. Since most of the communication protocols have not been specifically designed for the needs of connected medical devices, there is a need to classify the available IoT communication technologies in terms of security. In this paper we classify IoT communication protocols, with respect to their application in IoMT. Then we describe the main characteristics of IoT communication protocols used at the perception, network and application layer of medical devices. We examine the inherent security characteristics and limitations of IoMT-specific communication protocols. Based on realistic attacks we identify available mitigation controls that may be applied to secure IoMT communications, as well as existing research and implementation gaps.