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.

Social Discounting Under Uncertainty: A Cross-Country Comparison

Abstract: Recent research suggests that social cost-bene―t analysis should be conducted with a declining discount rate. For instance, Newell and Pizer [23] show that the U.S. certainty-equivalent discount rate declines through time, using a simple autoregressive model of U.S. interest rates. This paper extends that line of research, estimating both autoregressive and regime-switching models of real interest rates to determine certainty-equivalent discount rates in Australia, Canada, Germany and the United Kingdom. It is found that the regime-switching model is a better model of past interest rate behavior for all four countries. This model tends to produce a more rapid decline in certainty-equivalent discount rates. The paper provides applications to the economics of climate change and nuclear power.

Geopolitical Risks, Returns, and Volatility in Emerging Stock Markets: Evidence from a Panel GARCH Model

Abstract: In this article, we analyze the role of country-specific and global geopolitical risks (GPRs) on the returns and volatility of 18 emerging market economies over the monthly period of 1998:1...

Ratsnake: a versatile image annotation tool with application to computer-aided diagnosis.

Abstract: Image segmentation and annotation are key components of image-based medical computer-aided diagnosis (CAD) systems. In this paper we present Ratsnake, a publicly available generic image annotation tool providing annotation efficiency, semantic awareness, versatility, and extensibility, features that can be exploited to transform it into an effective CAD system. In order to demonstrate this unique capability, we present its novel application for the evaluation and quantification of salient objects and structures of interest in kidney biopsy images. Accurate annotation identifying and quantifying such structures in microscopy images can provide an estimation of pathogenesis in obstructive nephropathy, which is a rather common disease with severe implication in children and infants. However a tool for detecting and quantifying the disease is not yet available. A machine learning-based approach, which utilizes prior domain knowledge and textural image features, is considered for the generation of an image force field customizing the presented tool for automatic evaluation of kidney biopsy images. The experimental evaluation of the proposed application of Ratsnake demonstrates its efficiency and effectiveness and promises its wide applicability across a variety of medical imaging domains.

Intrusion Detection with Neural Networks and Watermarking Techniques for MANET

Abstract: In mobile ad hoc networks (MANET) specific Intrusion Detection Systems (IDSs) are needed to safeguard them since traditional intrusion prevention techniques are not sufficient in the protection of MANET. In this paper we present an intrusion detection engine based on neural networks combined with a protection method, which is based on watermarking techniques. We exploit the advantages of information visualization and machine learning techniques in order to achieve intrusion detection. Then, we authenticate the maps produced by the application of the intelligent techniques using a novel combined watermarking embedded method. The performance of the proposed model is evaluated under different traffic conditions, mobility patterns and visualization metrics, showing its high efficiency.