Angelos Mimis

Exploring the relationship between efficiency and profitability

Purpose – This paper aims to identify the relationship between efficiency and profitability by using data from Greek meat processing companies over the period 1994‐2007.Design/methodology/approach – The relationship of efficiency and profitability is studied, by applying a new performance decomposition model. This method is capable of making valid and consistent inferences about the performance of a two‐stage production system, as well as the main sources of inefficiencies within a company.Findings – A poor performance over the study period is observed in the sample companies. The low performance is mainly due to the low profitability. The results do not confirm the existence of a positive strong correlation between efficiency and profitability. The companies that have the capability of producing their products with the best practices are not always capable of generating the maximum profits.Practical implications – The need for the improvement of performance has two aspects: first, it is a demand for the ...

Property valuation with artificial neural network: the case of Athens

The purpose of this article is to examine the application of an artificial neural network (ANN) approach in property valuation. The approach has been enhanced by the use of a geographic information system (GIS) to enrich the explanatory variables and model the spatial dimension of the problem. The sample data used contain information of 3150 properties in the broader area of Athens. Various internal physical (structure quality and quantity) and external environmental characteristics (neighbourhood characteristics and transportation access) of the properties are available. In order to incorporate these environmental variables, the GIS was used to employ location-based characteristics. In our approach, the multilayer perception network has been employed and the results have been compared with the traditional approach of the spatial lag model. The comparison demonstrates that ANN gives more consistent predictions in the area of Athens. Our results reveal the non-linear relationships of the value of a property with respect to floor space and age. Finally, spatial variation of the values of the properties in broader area of Athens is illustrated.

Mapping population aging in Europe: how are similar needs in different countries met by different family structures?

This paper focuses primarily on the demographic and social structures across Europe aiming to portray how similar needs for care of the elderly population (justified on health outcomes), are addressed in different ways across European countries. To approach this issue, we focus first on mapping the ‘needs for care’ – a rough measure of demand for care, and then on family structures – characterizing an institution linked with the provision or supply of care. Attention turns next to linking these aspects, focusing on the types of care provided as a response to the needs of the elderly, distinguishing between informal (defined as unpaid personal care provided by family members) and formal care (defined as paid help provided by professionals and private providers). Mapping these trends, via choropleth maps, the emerging picture suggests that the same needs for elderly care are met via different channels across European countries: Southern countries appear to rely more on informal channels of care provision, while private providers (i.e. paid care) represent the dominant pattern in the North, as well as in most of the Continental counties. This difference is mirrored by a greater involvement of formal structures linked to the Welfare State as one goes further North; indeed the two – family ties and Welfare State involvement – proceed in parallel.

Classification of circulation types over Eastern mediterranean using a self-organizing map approach

In this study an Artificial Neural Network called Self-Organizing Map (SOM) is used in order to classify the synoptic circulation over Europe and especially Eastern Mediterranean. The classification of circulation types is an effective way of summarizing and describing the atmospheric circulation and it is useful in climatology because it provides a better understanding of the climatic variability over an area. Here, the SOM methodology is applied on winter daily geopotential height anomalies of the 500 hPa level, for the period 1971–2000. Twelve unique circulation patterns are identified. Eight of these types are characterized as cyclonic, representing 61% of the total days examined and four types are characterized as anticyclonic, representing 39% of the study period. The results of this classification are comparable to other objective classifications applied on the same study region and present a similar image. Therefore, the SOM methodology is found to be applicable and useful in the classification of circulation types.

An AZP-ACO method for region-building

In this paper a regionalization algorithm which groups spatial areal objects into homogeneous zones is presented. The proposed method is based on Automatic Zoning Problem (AZP) procedure which is extended to use the Ant Colony Optimization (ACO) technique. The results produced are compared to the original AZP method. Both methods are applied into the classification of economic data in a post code level on the area of Athens.

A geographical information system approach for evaluating the optimum location of point-like facilities in a hierarchical network

Τhis paper discusses a methodology for solving the problem of finding an optimum location for a number of facilities entering an existing hierarchical network. The locational optimization problem is approached with a continuous model. The facilities are considered as point-like. The proposed methodology solves these problems by using Voronoi diagrams to define the catchment area and minimizes the average distance traveled by the users. The approach is implemented by loose coupling between the Directed Tabu Search algorithm for continuous nonlinear optimization with constraints and the Geographical Information System where the cost function is evaluated. In the case study example, facilities operate in a hierarchical network consisting of bank branches and Automated Teller Machines (ATM) of a private Greek bank. A new bank branch location and the insertion of an ATM were examined and compared, providing an improvement of 25.6 and 12.8%, respectively. The proposed approach resulted in visualizing the optimum location on the map, providing the ability to study the modifications that occurred. This could be a useful tool in the hands of practitioners and provide new options in the decision-making process.

House price determinants in Athens: a spatial econometric approach

Abstract In this paper, we try to identify the price determinants in the biggest real estate market of Greece, the metropolitan area of Athens. For that purpose, various spatial econometric models are used to explore their prediction ability and we are displaying the variations in property prices for the wider area of Athens. These models have been compared based on different criteria such as model fit, the Akaike information criterion and variance of the residuals. Our results indicate that, in our case, the spatial general model is the most appropriate simultaneous autoregressive model when dealing with spatially autocorrelated prices of housing properties data, in terms of our selection criteria.

Technical efficiency of the Greek meatpacking industry in 1994–2007

The article employs a double-bootstrap data envelopment analysis to measure the technical efficiency of meatpacking companies in Greece and identify its determinants over the period of 1994-2007. The rationale for adopting this method is to yield bias-corrected efficiency scores of firms and robust inferences about its drivers. The empirical results indicate that the typical meatpacker of our sample operates with 89% efficiency and performance is higher for firms that are members of a group and adopt a strategy for increasing the skill of employees, while larger and older firms operate at lower efficiency.