An expert system for ranking companies and investments: wood industry case

Wood industry is a very important part of both the Greek Rural and industrial sector. The discovery of the differentiation in the level of growth and in the quality of financial management between the Greek wood companies can provide very important aid in the design of an effective rural development policy. The evaluation and ranking of Greek wood companies based on actual financial data is a very complicated task and it requires expertise knowledge and skills. On the other hand a computer expert system can perform validation and evaluation in an efficient way and can substitute human experts. An expert system was designed and developed towards this direction. It uses multicriteria analysis for each one of the wood companies based on actual financial data and it applies fundamental principles of fuzzy logic in order to calculate the expected intervals of flows for the following years.

El mercado de madera en rollo en Grecia: una aproximación empírica

The present study aims to determine the factors affecting the producer price of the industrial round wood. The factors examined as determinants of the producer price are the volume of domestic production, imports and exports of the industrial round wood in Greece. As a proxy for the producer price, the round wood of long length (> 2m) price is employed. For the achievement of the aforementioned objective, Johansen cointegration technique was implemented. The results confirmed the existence of a sole long-run relationship between the variables studied while the estimation of the vector error correction model indicated a statistically significant speed in the long-term equilibrium. The implementation of the Granger causality test has shown that the producer’s price is affected by the imported volume while the domestic production is determined by the volume of exports. Finally, the producer prices are determined by the exports and the imports of the Greek wood sector and vice versa. All the aforementioned results are consistent with the classic supply-demand economic theory.Este manuscrito tiene la intención de determinar los factores que afectan el precio de producción de la madera en rollo industrial. Como proxy para el precio de producción, se utiliza el precio de la madera en rollo de gran longitud (> 2 m). Los factores examinados como determinantes del precio de producción son el volumen del producción de las importaciones y el volumen de las exportaciones de la madera en rollo industrial en el sector griego. La aplicación de cointegración de Johansen ha indicado una relación de largo tiempo única entre las variables estudiadas. Además, la aplicación del VECM ha demostrado una velocidad importante en el equilibrio a largo plazo, mientras que la prueba de causalidad de Granger ha puesto de manifiesto que el precio del productor se encuentra fuertemente afectada por el volumen importado, mientras que la producción nacional se determina por el volumen de las exportaciones. Por último, se determinan los precios de producción, así como las exportaciones y las importaciones del sector griego de la madera. Todos estos resultados son compatibles con la teoría clásica de la oferta y la demanda

Non linearities and chaos in stock price behavior of Greek oil sector; The case of Hellenic Petroleum S.A.

The behaviour of different financial or economic time series is captured mainly by nonlinear models. The present study investigates the underlying process of the stock price returns time series of the oil sector taking as an example the case of Hellenic Petroleum SA. The data used are daily for over a 13 – year period. Nonlinearities are detected with different univariate tests that survey the independence and nonlinear deterministic structure of the time series studied. The data employed for these tests are the closing prices of Hellenic Petroleum SA. All the tests confirm the existence of nonlinearities in the time series studied. Furthermore, we employ a Layapunov test to detect the chaotic behaviour of the stock prices. Finally, we estimate the noisy Mackey – Glass model, which is an equation with errors that follow an F- GARCH (p, q) process. This model is structured in order to enable us to interpret the volatility clustering as an endogenous phenomenon

MARKET AND ECONOMIC DEVELOPMENT IN BULGARIA

The present paper tests empirically the existence of a causal relationship between the economic growth and the development in the banking and stock market in transition economies and especially the case of Bulgaria. The Johansen cointegration test indicated one long – run relationship between the banking sector, the stock market and the economic growth while the application of the Granger causality test indicated a bilateral relationship between the economic growth and the development in the stock market, as well as between the economic growth and the development in banking sector. Finally, a unilateral relationship was concluded between the development in credit and stock market

Modeling sheep pox disease from the 1994-1998 epidemic in Evros Prefecture, Greece.

Sheep pox is a highly transmissible disease which can cause serious loss of livestock and can therefore have major economic impact. We present data from sheep pox epidemics which occurred between 1994 and 1998. The data include weekly records of infected farms as well as a number of covariates. We implement Bayesian stochastic regression models which, in addition to various explanatory variables like seasonal and environmental/meteorological factors, also contain serial correlation structure based on variants of the Ornstein–Uhlenbeck process. We take a predictive view in model selection by utilizing deviance-based measures. The results indicate that seasonality and the number of infected farms are important predictors for sheep pox incidence

Abnormal temporal lobe morphology in asymptomatic relatives of patients with hippocampal sclerosis: A replication study.

We investigated gray and white matter morphology in patients with mesial temporal lobe epilepsy with hippocampal sclerosis (mTLE+HS) and first-degree asymptomatic relatives of patients with mTLE+HS. Using T1-weighted magnetic resonance imaging (MRI), we sought to replicate previously reported findings of structural surface abnormalities of the anterior temporal lobe in asymptomatic relatives of patients with mTLE+HS in an independent cohort. We performed whole-brain MRI in 19 patients with mTLE+HS, 14 first-degree asymptomatic relatives of mTLE+HS patients, and 32 healthy control participants. Structural alterations in patients and relatives compared to controls were assessed using automated hippocampal volumetry and cortical surface-based morphometry. We replicated previously reported cortical surface area contractions in the ipsilateral anterior temporal lobe in both patients and relatives compared to healthy controls, with asymptomatic relatives showing similar but less extensive changes than patients. These findings suggest morphologic abnormality in asymptomatic relatives of mTLE+HS patients, suggesting an inherited brain structure endophenotype

Internet functions in marketing: multicriteria ranking of agricultural SMEs websites in Greece

Δημοσιεύσεις μελών--ΣΔΟ--Τμήμα Λογιστικής, 2013The invasion of new technologies combined with the high cost for running shop force enterprises to search for new sales methods. Network applications and ICT (Information and Communication Technology) can help achieve e-commerce goals. In Greece, many enterprises in the agro-food and drink sectors are already present on the internet. This paper studies the adoption of e-commerce on websites that support e-commerce activities within the agro-food and drink sectors. Therefore, the paper aims to identify and evaluate their qualitative and quantitative content characteristics, rank them according to 6 content characteristics/criteria using the multicriteria method of PROMETHEE II and classify them in groups of similar adoption. The findings of this study reveal the rate of adoption of e-commerce in the sectors and can serve as a valuable model for the designers of websites that promote e-commerce activities within the wider areas of food and drinks

Seizure detection using EEG and ECG signals for computer-based monitoring, analysis and management of epileptic patients

This is the accepted manuscript version of the following article: Iosif Mporas, “Seizure detection using EEG and ECG signals for computer-based monitoring, analysis and management of epileptic patients”, Expert Systems with Applications, Vol. 42(6), December 2014. The final published version is available at: http://www.sciencedirect.com/science/article/pii/S0957417414007763?via%3Dihub © 2014 Elsevier Ltd. All rights reserved.In this paper a seizure detector using EEG and ECG signals, as a module of a healthcare system, is presented. Specifically, the module is based on short-time analysis with time-domain and frequency-domain features and classification using support vector machines. The seizure detection module was evaluated on three subjects with diagnosed idiopathic generalized epilepsy manifested with absences. The achieved seizure detection accuracy was approximately 90% for all evaluated subjects. Feature ranking investigation and evaluation of the seizure detection module using subsets of features showed that the feature vector composed of approximately the 65%-best ranked parameters provides a good trade-off between computational demands and accuracy. This configurable architecture allows the seizure detection module to operate as part of a healthcare system in offline mode as well as in online mode, where real-time performance is needed.Peer reviewe