Vassilios Chatzis

International Hellenic University · School of Economics and Business Administration

252 δημοτικά σχολεία πανελληνίως, επιλεγμένα με τη μέθοδο της στρωματοποιημένης δειγματοληψίας. Λέξεις κλειδιά: Τεχνολογίες Πληροφορίας και Επικοινωνιών, Οργάνωση και Διοίκηση, Σχολική Μονάδα, Λειτουργίες Διοίκησης Εισαγωγή Ο ρόλος του διευθυντή μιας σχολικής μονάδας τα τελευταία χρόνια έχει προσεγγίσει κατά πολύ το ρόλο που διαδραματίζει ο manager...

This research concerns the modeling methods of System Dynamics and Simulation using the Anylogic software. The purpose is to show how to use software to provide answers to supply chain issues, in particular inventory policy. We developed a supply chain simulation model that connects a retailer, a wholesaler and a factory. Using an optimization expe...

This paper presents a new geometrical feature based on iris geometry for automatic children detection in digital images. The proposed feature is based on simple geometrical measures of face elements and especially iris. Iris outer boundary is approximated as a circle and the proposed feature is defined using the iris area and the distance of iris f...

This paper presents a novel configurable design for the implementation of basic morphological operations based on Quantum-dot Cellular Automata (QCA) technology. QCA is a promising technology in the field of nanoelectronics that could be utilized in many image processing applications. QCA architecture will provide better performance by exploiting p...

This chapter presents the implementation of Quantum-dot Cellular Automata (QCA) technology for image processing mathematical morphology operations. The basic concepts for both mathematical morphology and QCA technology are briefly described. QCA is a very promising emerging technology in the field of nanoelectronics that seems to suit well with ima...

This paper presents a new approach for the detection of image objects, based on active contours by exploiting techniques of curve evolution. The proposed model of active contours is based on the minimization of a fuzzy energy, which can be seen as a particular case of a minimal partition problem. Unlike to existing methods, the adopted fuzzy energy...

The continuing development of smaller electronic devices into the nanometer regime offers great possibilities of highly parallel computing systems, as it allows to reduce power consumption and device sizes and to increase operating speed. Quantum-dot Cellular Automata (QCA) has been proposed as an alternative for nanoelectronic devices and introduc...

This study presents a new approach for image clustering, which is based on a novel workspace derived from the empirical mode decomposition (EMD). The proposed algorithm exploits the EMD, which can decompose any non-linear and non-stationary data into a number of intrinsic mode functions (IMFs). The intermediate IMFs of the image histogram have very...

This paper presents a novel unsupervised image clustering approach based on the image histogram, which is processed by the empirical mode decomposition (EMD). The proposed algorithm exploits an intermediate step derived from the empirical mode decomposition, which can decompose any nonlinear and non-stationary data into a number of intrinsic mode f...

This paper presents a novel physics-based dual deformable model to detect objects in an image. This model is more efficient than the known methods since it can detect objects whose boundaries are not necessarily defined by gradient. It minimizes an energy which can be seen as a particular case of a minimal partition problem. This energy is used as...

This paper introduces a distance metric between two distributions that we call the Deformation Distance (DeD). The DeD is based on the "energy" that must be paid to deform one distribution into the other, presenting a perceptual similarity match better than other distribution distances. The DeD relies on the distribution's frequency-based features....

A novel image clustering method based on the image histogram, which is processed by the empirical mode decomposition (EMD) is presented. An intermediate step derived from the EMD, which can decompose any nonlinear and non-stationary data into a number of intrinsic mode functions (IMFs) is exploited. The IMFs of the image histogram have interesting...

This paper presents a variation of fuzzy c-means (FCM) algorithm that provides image clustering. The proposed algorithm incorporates the local spatial information and gray level information in a novel fuzzy way. The new algorithm is called fuzzy local information C-Means (FLICM). FLICM can overcome the disadvantages of the known fuzzy c-means algor...

This paper presents a novel fast model for active contours to detect objects in an image, based on techniques of curve evolution. The proposed model can detect objects whose boundaries are not necessarily defined by gradient, based on the minimization of a fuzzy energy, which can be seen as a particular case of a minimal partition problem. This fuz...

This paper presents a novel approach for object skeleton family extraction. The introduced technique utilizes a 2-D physics-based deformable model that parameterizes the objects shape. Deformation equations are solved exploiting modal analysis, and proportional to model physical characteristics, a different skeleton is produced every time, generati...

The purpose of this paper is to present the web-based application “e-project” accessing a relational database through internet. The tools that have been used to build this application are MySQL as a relational database system for the database design, TCL as a computer language for the development of the application, JavaScript language scripts has...

This paper addresses the issue of accurate, effective, computationally efficient, fast, and fully automated 2-D object orientation and scaling factor estimation. The object orientation is calculated using object principal axes estimation. The approach relies on the object's frequency-based features. The frequency-based features used by the proposed...

In this paper a novel design of a quantum-dot cellular automata (QCA) 2 to 1 multiplexer is presented. The objective is the development of a modular design methodology which can be used to design 2n to 1 multiplexers using building blocks. For the QCA implementation a careful consideration is taken into account concerning the design in order to inc...

The main aim of this paper is the construction of a model, which involves the development of an application for estimating the real patient daily hospital expenses. These expenses concerns to the appropriate medicines, the necessary medical tests that along with all the requisite medical material for patient proper daily hospital treatment. Accordi...

This paper presents an internet application that helps students to book laboratories groups. The application is based on a relational database. The aim of this application is to automate the booking procedure, to provide speed, flexibility and efficiency for users. The application has been developed only using open source software. MySQL has been p...

This paper presents a web-based text and html editing application. The user can manipulate the text almost as well as in a word processor and add the most frequently used html elements such as buttons, text areas and text fields. Since the document is formed the application can generate the html code for it. The application is relied on open source...

A major disadvantage of image retrieval systems is their lack of objects orientation and scaling matching. This paper addresses the issue of accurate, effective, computationally efficient, fast and fully-automated 2D object orientation and scaling determination. The approach relies on the objects frequency-based features. The frequency-based featur...

Industrial product quality is frequently assessed using up to second-order statistics of populations of measurements. Lately, a fuzzy interval number (FIN) was used for representing a whole population of samples. It turns out that a FIN can asymptotically capture statistics of all orders. The space F of FINs, including both conventional (fuzzy) num...

This paper presents the electronic application “e-Bank” accessing a relational database through internet. The application is relied on open source software. MySQL is used as a relational database system for the database design. Scripting language TCL was preferred as the computer language used for the development of the application. The aim of the...

This paper presents the electronic application “e-Exams” accessing a relational database through internet. The application is relied on open source software. MySQL is used as a relational database system for the database design. Scripting language TCL was preferred as the computer language used for the development of the application. The aim of the...

In this paper, the Morphological Skeleton Interpolation (MSI) algorithm is presented. It is an efficient shape-based interpolation method used for interpolating slices between successive slices of a 3-D object. It is based on the well known mathematical morphology procedure of morphological skeletonization, that is used as a representation of an ob...

In this chapter, an overview of the applications of several fuzzy operators in image processing and analysis is presented. First, the fuzzy location and scale estimators based on the extension principle, are presented. The definitions of the fuzzy nonlinear means, the fuzzy location and scale estimators based on fuzzy order statistics and other fuz...

In this paper, the generalized fuzzy mathematical morphology (GFMM) is proposed, based on a novel definition of the fuzzy inclusion indicator (FII). FII is a fuzzy set used as a measure of the inclusion of a fuzzy set into another, that is proposed to be a fuzzy set. It is proven that the FII obeys a set of axioms, which are proposed to be extensio...

In this paper, the morphological skeleton interpolation (MSI) algorithm is presented. It is an efficient, shape-based interpolation method used for interpolating slices in a three-dimensional (3-D) binary object. It is based on morphological skeletonization, which is used for two-dimensional (2-D) slice representation. The proposed morphological sk...

The use of clustering algorithms for decision-level data fusion is proposed. Person authentication results coming from several modalities (e.g., still image, speech), are combined by using fuzzy k-means (FKM) and fuzzy vector quantization (FVQ) algorithms, and a median radial basis function (MRBF) network. The quality measure of the modalities data...

In this paper, the fuzzy scalar median (FSM) is proposed, defined by using ordering of fuzzy numbers based on fuzzy minimum and maximum operations defined by using the extension principle. Alternatively, the FSM is defined from the minimization of a fuzzy distance measure, and the equivalence of the two definitions is proven. Then, the fuzzy vector...

In this paper, the use of clustering algorithms for decision level data fusion is proposed. Person authentication results coming from several modalities (e.g. still image, speech), are combined by using the fuzzy k-means (FKM) and the fuzzy vector quantization (FVQ) algorithms, two modification of them that use fuzzy data FKMfd and FVQfd, and a med...

In this paper the use of a fast algorithm for implementing shape decomposition of 3D binary objects is proposed. Shape decomposition is performed by successive 3D erosions and dilations, using 3D structuring elements of arbitrary size and shape. The proposed fast shape decomposition algorithm is based on a fast implementation of the basic morpholog...

In this correspondence, the extension principle is used in order to fuzzify location and scale estimators when used on fuzzy numbers. First, fuzzy nonlinear means are defined as extensions of the corresponding crisp means. Fuzzy L location and scale estimators, which are based on fuzzy-order statistics, are defined as extensions of the crisp L loca...

Randomized Hough transform (RHT) has been recently proposed as a new and efficient variation of the Hough transform for curve detection. In this paper the RHT is combined with the fuzzy cell Hough transform (FCHT) and a new variation, the randomized fuzzy cell Hough transform (RFCHT) is proposed. The p-dimensional parameter space of Hough transform...

In this paper, the Fuzzy Vector Median is proposed, defined as an extension of Vector Median. It is based on a novel distance definition of multidimensional fuzzy numbers (fuzzy vectors), which satisfy the property of angle decomposition. The proposed distance of two fuzzy vectors depends on the classical distance of the fuzzy set centers and on th...

In this paper a new variation of Hough Transform is proposed. It can be used to detect shapes or contours in an image, with better accuracy, especially in noisy images. The parameter space of Hough Transform is split into fuzzy cells which are defined as fuzzy numbers. This fuzzy split provides the advantage to use the uncertainty of the contour po...

This paper presents a simulation of an access control system that deals with the problem of access control and copyright protection for broadcasted image-related services. The services that concentrate our interest include mainly Pay-TV, but also the existing and forthcoming multimedia services which are expected to share the same channels as digit...

In this paper a new variation of Hough transform is proposed. The parameter space of Hough Transform is iteratively split into fuzzy cells which are defined as fuzzy numbers. Each fuzzy cell corresponds to a fuzzy curve in the spatial domain. After each iteration the fuzziness of the cells is reduced and the curves are estimated with better accurac...

In this paper a new variation of Hough transform is proposed. The parameter space of Hough transform is recursively roughly split into fuzzy cells which are defined as fuzzy numbers. This fuzzy partition of the parameter space provides the advantage to use the uncertainty of the contour points location, which is increased when noisy images have to...