Research Interests:
Research Interests:
This paper introduces a software tool that supports the activities of a novel, reuse-based development framework, which focuses on assessing the suitability level of candidate components. The tool enables the creation of a specifications... more
This paper introduces a software tool that supports the activities of a novel, reuse-based development framework, which focuses on assessing the suitability level of candidate components. The tool enables the creation of a specifications profile using a semi-formal natural language, which describes the desired functional and non-functional properties of the components sought. It also offers the means to parse the profile automatically and translate it into instance values of a dedicated CBSE ontology. Finally, the tool performs matching between required and offered component properties at the level of ontology items and suggests the most suitable components to consider for integration based on a suitability ratio calculated.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
This paper proposes a strategic management methodology using influence diagrams to represent and model decision problems. While decision trees have been extensively used for this purpose and are still highly useful, fuzzy influence... more
This paper proposes a strategic management methodology using influence diagrams to represent and model decision problems. While decision trees have been extensively used for this purpose and are still highly useful, fuzzy influence diagrams, a new representation for decision problems, outperform them in many respects. This paper describes influence diagrams, proposes their extension via fuzzy logic and demonstrates their use
Research Interests:
This paper proposes tree structured multi-layer fuzzy cognitive maps for modelling large-scale and complex real world problems and supporting the decision making process. Large-scale problems are characterized by a large number of... more
This paper proposes tree structured multi-layer fuzzy cognitive maps for modelling large-scale and complex real world problems and supporting the decision making process. Large-scale problems are characterized by a large number of parameters, concepts, variables, nonlinearities and uncertainties that make their analysis and modelling a very difficult task. The objective of the proposed methodology is to give an alternative approach
Research Interests:
Abstract This paper proposes an extension to multilayered fuzzy cognitive maps (ML-FCMs) and introduces a new methodology based on ML-FCMs aiming at enhancing their capabilities for scenario analysis and forecasting. The main issue here... more
Abstract This paper proposes an extension to multilayered fuzzy cognitive maps (ML-FCMs) and introduces a new methodology based on ML-FCMs aiming at enhancing their capabilities for scenario analysis and forecasting. The main issue here is the ...
Research Interests:
This paper presents the key concepts of an integrated software tool designed to contribute to the decision-making process in the field of crisis modelling and management. The tool relies on the use of Fuzzy Cognitive Maps (FCMs), which... more
This paper presents the key concepts of an integrated software tool designed to contribute to the decision-making process in the field of crisis modelling and management. The tool relies on the use of Fuzzy Cognitive Maps (FCMs), which combine elements of fuzzy logic and neural networks to depict a cognitive scene of interacting concepts (nodes/levels) and their causal relationships (edges/weights).
Research Interests:
This paper proposes an extension of Genetically Evolved Fuzzy Cognitive Maps (GEFCMs) used for decision-making, aiming at increasing their reliability and overcoming its main weakness which lies with the recalculation of weights... more
This paper proposes an extension of Genetically Evolved Fuzzy Cognitive Maps (GEFCMs) used for decision-making, aiming at increasing their reliability and overcoming its main weakness which lies with the recalculation of weights corresponding to more than one concept every time a new multiple scenario is introduced. A new evolutionary approach is proposed to support multi-objective decision-making based on the introduction
Research Interests: Genetics, Mathematics, Computer Science, Decision Making, Genetic Algorithms, and 10 moreFuzzy set theory, Decision Support Systems, Genetic Algorithm, Problem Solving, Multi objective optimization, Decision Support, Evolutionary Algorithm, Fuzzy Cognitive Map, Boolean Satisfiability, and Optimal Solution
Research Interests:
ABSTRACT As modern computing relies more and more on distributed solutions of services and resources over the cloud, the need of potential users to assess whether the transition from traditional software systems to the cloud would be to... more
ABSTRACT As modern computing relies more and more on distributed solutions of services and resources over the cloud, the need of potential users to assess whether the transition from traditional software systems to the cloud would be to their benefit becomes even greater. Cloud vendors also seek ways to study beforehand the behavior of potential users with respect to their decision to adopt the cloud environment so as to take actions towards enhancing the positive side. Therefore, the study of the parameters forming the environment behind the cloud adoption decision is of paramount importance to both users and vendors. In this context the present paper proposes a multi-layer FCM approach which models a number of factors which play a decisive role to the cloud adoption issue and offers the means to study their influence. The factors are organized in different layers which focus on specific aspects of the cloud environment, something which, on one hand, enables tracking the causes for the decision outcome, and on the other offers the ability to study the dependencies between the leading determinants of the decision. The construction and analysis of the model is based on factors reported in the relevant literature and the utilization of experts’ opinion. The efficacy and applicability of the proposed approach are demonstrated through four real-world experimental cases.
Research Interests:
ABSTRACT Software testing is an important phase of software development that helps eliminating the possibility of project failure. As software systems get more complicated and larger in size, testing needs to constantly evolve and provide... more
ABSTRACT Software testing is an important phase of software development that helps eliminating the possibility of project failure. As software systems get more complicated and larger in size, testing needs to constantly evolve and provide more "sophisticated'' techniques, like automatic, self-adaptive mutation testing, targeting at improving the efficiency and effectiveness of the testing phase by handling the increased complexity that leads to increased demands in time and effort. Mutation testing is the procedure of applying a series of operators on correctly functioning programs so as to induce "faults'' that correspond to real, common programming errors and then assess the ability of a set of test cases to reveal those errors. We introduce a novel approach for identifying and correcting faults in Java source code with the use of code slicing, mutation testing and Genetic Algorithms. Three different categories of experiments are used to assess the effectiveness of the proposed solution, demonstrating its applicability on a variety of programs and type of errors. The results are quite encouraging suggesting that the approach is able to dynamically detect faults and propose the appropriate corrections.
Research Interests:
Research Interests:
Electronic Patient Record Systems (EPRS) hold an exceptional position in the field of Medical Informatics. The aim of such systems is to replace the traditional paper-based patient recording, offering at the same time a set of advanced... more
Electronic Patient Record Systems (EPRS) hold an exceptional position in the field of Medical Informatics. The aim of such systems is to replace the traditional paper-based patient recording, offering at the same time a set of advanced data exchange functionalities modern computers and networks can offer. MEDARIST II is a flexible and efficient EPRS, designed to serve surgery wards. This paper focuses on the analysis of certain social and ethical factors that must be taken into account when designing EPRS from an end-user's point of view. Furthermore the paper aims at demonstrating the methods used by the MEDARIST II system to cover usability and human-computer interaction aspects.
Electronic Patient Record Systems (EPRS) hold an exceptional position in the field of Medical Informatics. The aim of such systems is to replace the traditional paper-based patient recording, offering at the same time a set of advanced... more
Electronic Patient Record Systems (EPRS) hold an exceptional position in the field of Medical Informatics. The aim of such systems is to replace the traditional paper-based patient recording, offering at the same time a set of advanced data exchange functionalities modern computers and networks can offer. ARISTOPHANES is a flexible and efficient EPRS, designed to serve surgery wards. This paper focuses on the analysis of certain social and ethical factors that must be taken into account when designing EPRS from an end-user's point of view. Furthermore the paper aims at demonstrating the methods used by the ARISTOPHANES system to cover usability and human-computer interaction aspects.
Research Interests:
This paper presents the dynamic behaviour of a hybrid system comprising fuzzy cognitive maps (FCM) and genetic algorithms, and focuses on the behaviour of the former under equilibrium at fixed points or limit cycle. More specifically, the... more
This paper presents the dynamic behaviour of a hybrid system comprising fuzzy cognitive maps (FCM) and genetic algorithms, and focuses on the behaviour of the former under equilibrium at fixed points or limit cycle. More specifically, the theoretical background of both the equilibrium and limit cycle behaviours is examined and a new methodology for eliminating the limit cycle phenomenon is
Research Interests:
Research Interests:
AbstractE-commerce systems' poor and incomplete design fail to meet users expectations and businesses goals. A major factor of failure of these systems is ignoring important requirements that result from human, cultural, social and... more
AbstractE-commerce systems' poor and incomplete design fail to meet users expectations and businesses goals. A major factor of failure of these systems is ignoring important requirements that result from human, cultural, social and organizational factors. The present work introduces a new Web engineering methodology for performing requirements elicitation through a model called SpiderWeb. This is a cross-relational structure comprised of three main axons: Country Characteristics, User Requirements and Application Domain. The purpose of this model is to provide a simple way for analysts to identify these hidden requirements which otherwise could be missed or given little attention. Factors gathering is performed based on a certain form of ethnography analysis, which is conducted in a short-scale and time-preserving manner, taking into consideration the importance of immediacy in deploying e-commerce applications. Two e-commerce systems were developed and evaluated. The first was based on the proposed SpiderWeb methodology and the second on the WebE process. Finally, a survey of purchase preference was conducted demonstrating and validating the applicability and effectiveness of the SpiderWeb methodology.
Research Interests:
ABSTRACT The paper provides an in depth analysis of empirical evidence on the state of practice within the agile domain obtained through a survey conducted in 2012. The context of focus is agile software processes and teams and the... more
ABSTRACT The paper provides an in depth analysis of empirical evidence on the state of practice within the agile domain obtained through a survey conducted in 2012. The context of focus is agile software processes and teams and the particular topics of interest revolve around three axes: (i) communication; (ii) project management; and (iii) quality assurance and validation. The aim of the survey is to deliver the current levels of agile adoption and practices as these are recorded in the responses of professionals in IT services and the software industry. The goal of the survey is to provide evidence-based assessment of the level of agile adoption by software development organizations, in relation to the general profile of the respondents (country of origin, business sectors, roles, etc.) and compared with different types of practices followed, such as agile techniques adopted, team organization and communication techniques, and project management. Particular patterns and trends are identified in the survey connecting the use of the agile paradigm with the aforementioned practices and investigating its relation with the roles of the respondents and the business strategies of their organizations. Copyright © 2014 John Wiley & Sons, Ltd.
Research Interests:
ABSTRACT Context In software project management, the distribution of resources to various project activities is one of the most challenging problems since it affects team productivity, product quality and project constraints related to... more
ABSTRACT Context In software project management, the distribution of resources to various project activities is one of the most challenging problems since it affects team productivity, product quality and project constraints related to budget and scheduling. Objective The study aims to (a) reveal the high complexity of modelling the effort usage proportion in different phases as well as the divergence from various rules-of-thumb in related literature, and (b) present a systematic data analysis framework, able to offer better interpretations and visualisation of the effort distributed in specific phases. Method The basis for the proposed multivariate statistical framework is Compositional Data Analysis, a methodology appropriate for proportions, along with other methods like the deviation from rules-of-thumb, the cluster analysis and the analysis of variance. The effort allocations to phases, as reported in around 1500 software projects of the ISBSG R11 repository, were transformed to vectors of proportions of the total effort and were analysed with respect to prime project attributes. Results The proposed statistical framework was able to detect high dispersion among data, distribution inequality and various interesting correlations and trends, groupings and outliers, especially with respect to other categorical and continuous project attributes. Only a very small number of projects were found close to the rules-of-thumb from the related literature. Significant differences in the proportion of effort spent in different phrases for different types of projects were found. Conclusion There is no simple model for the effort allocated to phases of software projects. The data from previous projects can provide valuable information regarding the distribution of the effort for various types of projects, through analysis with multivariate statistical methodologies. The proposed statistical framework is generic and can be easily applied in a similar sense to any dataset containing effort allocation to phases. Keywords Software effort distribution; Phased effort analysis; Compositional data analysis; Biplot; Cluster analysis
Research Interests:
Research Interests:
Software project management consists of a number of planning, organizing, staffing, directing and controlling activities. Human resources feature prominently in all of these activities and, as a consequence, they can affect and determine... more
Software project management consists of a number of planning, organizing, staffing, directing and controlling activities. Human resources feature prominently in all of these activities and, as a consequence, they can affect and determine project management decisions. Therefore, in order to help guarantee the success of a software project, managers must take into consideration this type of resource when performing the aforementioned activities. This chapter specifically investigates human resources from a planning perspective and, in particular, focuses on the responsibilities of allocating developers and teams to project tasks, scheduling developers and teams, as well as forming development teams. These responsibilities are often challenging to undertake because they are accompanied by time, budget and quality constraints, which software project managers find difficult to balance correctly. The purpose of the chapter is to explore the most recent research work in the field of human resource allocation and scheduling, and to specifically examine the motivation behind each approach and the goals and benefits to real-world practitioners. In addition, the chapter investigates development team formation, which can be considered as an indirect method of allocating human resources to a software project. This perspective, in particular, sheds light on current and future trends, which lean towards incorporating human-centric aspects of software development in planning activities.
Research Interests:
We have experienced a huge increase in the development and usage of e-learning, particularly by academic institutions. Among the greatest advantages offered by distance learning to both academics and students is accessibility, mobility... more
We have experienced a huge increase in the development and usage of e-learning, particularly by academic institutions. Among the greatest advantages offered by distance learning to both academics and students is accessibility, mobility and collaboration. These advantages address only one aspect of the learning process. Other factors, such as the adoption of classical pedagogical methods to the new environment, the
Research Interests:
Reliably predicting software defects is one of the most significant tasks in software engineering. Two of the major components of modern software reliability modeling approaches are: 1) extraction of salient features for software system... more
Reliably predicting software defects is one of the most significant tasks in software engineering. Two of the major components of modern software reliability modeling approaches are: 1) extraction of salient features for software system representation, based on appropriately designed software metrics and 2) development of intricate regression models for count data, to allow effective software reliability data modeling and prediction. Surprisingly, research in the latter frontier of count data regression modeling has been rather limited. More specifically, a lack of simple and efficient algorithms for posterior computation has made the Bayesian approaches appear unattractive, and thus underdeveloped in the context of software reliability modeling. In this paper, we try to address these issues by introducing a novel Bayesian regression model for count data, based on the concept of max-margin data modeling, effected in the context of a fully Bayesian model treatment with simple and eff...
Research Interests:
Research Interests:
Cloud Computing has become nowadays a significant field of Information and Communication Technology (ICT). Both cloud providers and customers invest time and resources in an endeavor of the former to serve effectively the needs of the... more
Cloud Computing has become nowadays a significant field of Information and Communication Technology (ICT). Both cloud providers and customers invest time and resources in an endeavor of the former to serve effectively the needs of the latter so as to adopt efficiently such cloud services, based their needs. The decision to adopt cloud services falls within the category of complex and difficult to model real-world problems. Aiming to support the cloud adoption decision process, we propose in this paper an approach based on Fuzzy Cognitive Maps (FCM) which models the parameters that potentially influence such a decision. The construction and analysis of the map is based on factors reported in the relevant literature and the utilization of experts’ opinion. The proposed approach is evaluated through four real-world experimental cases and the suggestions of the model are compared with the customers’ final decisions. The evaluation indicated that the proposed approach is capable of capturing the dynamics behind the interdependencies of the participating factors.
Research Interests:
Dear Authors, We are happy to inform you that based on the evaluation of your paper entitled" A Fuzzy Cognitive Map Model for Estimating the Repercussions of Greek PSI on Cypriot Bank Branches in Greece" you are invited to submit an extended version for potential publication in a Special Issue on...more
Research Interests:
The aim of this paper is to evaluate the recipe that requires defence expenditure reductions in an environment of severe budget cuts together with rising costs. The case of Greece, a country that is in the process of recovering from a... more
The aim of this paper is to evaluate the recipe that requires defence expenditure reductions in an environment of severe budget cuts together with rising costs. The case of Greece, a country that is in the process of recovering from a six-year economic crisis, provides an example of an economy in which an import – substitution strategy via the promotion of the Hellenic Defence Industrial Base potential can contribute to both economic growth and unemployment reduction, thus adding to the effectiveness of the import-substitution policies employed and compromising between an austerity programme and the defence needs of the country.
Research Interests:
This paper applies computational intelligence methods to exchange rate forecasting. In particular, it employs neural network methodology in order to predict developments of the Euro exchange rate versus the U.S. Dollar and the Japanese... more
This paper applies computational intelligence methods to exchange rate forecasting. In particular, it employs neural network methodology in order to predict developments of the Euro exchange rate versus the U.S. Dollar and the Japanese Yen. Following a study of our series using traditional as well as specialized, non-parametric methods together with Monte Carlo simulations we employ selected Neural Networks (NNs)
Research Interests:
Page 1. An automatic software test-data generation scheme based on data flow criteria and genetic algorithms Andreas S. Andreou Department of Computer Science, University of Cyprus aandreou@cs.ucy.ac.cy Kypros A. Economides ...
Research Interests:
This paper proposes a dynamic software testing framework, which is able to analyse the source code of a program, create the necessary data structures for automatic testing, such as control flow graphs, and generate a near to optimum set... more
This paper proposes a dynamic software testing framework, which is able to analyse the source code of a program, create the necessary data structures for automatic testing, such as control flow graphs, and generate a near to optimum set of test cases with reference to a test coverage criterion. The framework consists of two sub-systems: the first is a program analysis system that identifies the type of statements and the complexity of conditions, performs analysis of variables, extracts code paths and creates the control flow graph (CFG) of the program under testing. The second is a test system that uses the CFG for automatically generating test data based on evolutionary computing. The latter system utilises a specially designed genetic algorithm to produce the set of test cases satisfying the selected coverage criterion. The efficacy and performance of the proposed testing approach is assessed and validated using a variety of sample programs.
Research Interests:
The software cost estimation process is one of the most critical managerial activities related to project planning, resource allocation and control. As software development is a highly dynamic procedure, the difficulty of providing... more
The software cost estimation process is one of the most critical managerial activities related to project planning, resource allocation and control. As software development is a highly dynamic procedure, the difficulty of providing accurate cost estimations tends to increase with development complexity. The inherent problems of the estimation process stem from its dependence on several complex variables, whose values are often imprecise, unknown, or incomplete, and their interrelationships are not easy to comprehend. Current software cost estimation models do not inspire enough confidence and accuracy with their predictions. This is mainly due to the models' sensitivity to project data values, and this problem is amplified because of the vast variances found in historical project attribute data. This paper aspires to provide a framework for evolving value ranges for cost attributes and attaining mean effort values using the Al-oriented problem-solving approach of genetic algorithms, with a twofold aim. Firstly, to provide effort estimations by analogy to the projects classified in the evolved ranges and secondly, to identify any present correlations between effort and cost attributes.
Research Interests:
Research Interests:
This work addresses the issue of software effort prediction via fuzzy decision trees generated using historical project data samples. Moreover, the effect that various numerical and nominal project characteristics used as predictors have... more
This work addresses the issue of software effort prediction via fuzzy decision trees generated using historical project data samples. Moreover, the effect that various numerical and nominal project characteristics used as predictors have on software development effort is investigated utilizing the classification rules extracted. The approach attempts to classify successfully past project data into homogeneous clusters to provide accurate and
Research Interests:
Page 1. Nonlinear analysis and forecasting of a brackish karstic spring N. Lambrakis,1,2 AS Andreou,2,3 P. Polydoropoulos,2,4 E. Georgopoulos,3 and T. Bountis2,5 Abstract. Nonlinear methods and artificial neural network ...
Research Interests:
Research Interests:
... Andreas S. Andreou and George A. Zombanakis Abstract ... (2005). Two more contributions, namelyAthanassiou and Kollias (2002) and Kollias and Sirakoulis (2002), tackle the effects of this issue rather than the issue itself, on foreign... more
... Andreas S. Andreou and George A. Zombanakis Abstract ... (2005). Two more contributions, namelyAthanassiou and Kollias (2002) and Kollias and Sirakoulis (2002), tackle the effects of this issue rather than the issue itself, on foreign trade and arms imports respectively. ...