Alexandros S. Karakos

Alexandros S. Karakos
Democritus University of Thrace | DUTH · Department of Electrical and Computer Engineering

PhD

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64
Publications
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560
Citations

Publications

Publications (64)
Book
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Ως οδηγός προγραμματισμού της γλώσσας C, το βιβλίο αυτό εισάγει προοδευτικά τον αναγνώστη στις βασικές έννοιες και ιδιαιτερότητες της γλώσσας, για την κατανόηση των οποίων αναπτύσσονται πάρα πολλά μικρά αλλά και εκτενή λυμένα υποδειγματικά παραδείγματα προγραμμάτων. Κάθε καινούργια έννοια συνοδεύεται από ένα απλό παράδειγμα, το οποίο στη συνέχεια ε...
Article
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Στην παρούσα εργασία περιγράφουμε το πλαίσιο εφαρμογής του διαδικτυακού μαθήματος «Learning by Six Thinking Hats” στο οποίο εφαρμόσαμε και αξιολογήσαμε στην εξ αποστάσεως διαδικτυακή επιμόρφωση των εκπαιδευτικών τη μεθοδολογία «six thinking hats» του E. De. Bono. Το αντικείμενο της επιμόρφωσης ήταν η μάθηση μέσω της τέχνης (artful thinking) και η μ...
Conference Paper
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Nowadays, as e-learning is increasingly used in education, it is useful to know what are the critical factors for its successful implementation in higher education institutes. This research has two main objectives. The initial objective is to clarify and categorize the Critical Success Factors (CSF) of education with the use of a Learning Managemen...
Conference Paper
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Authors propose a new educational course evaluation framework and architecture for automatic (course evaluation intelligent mining) knowledge discovery at the web social media and search meta-engines. The proposed architecture shall provide an additional educational tool for an institution's course evaluation process, apart from the already propose...
Conference Paper
Full-text available
Business Intelligence is becoming an important factor that can help organizations in managing, developing and communicating their valuable goods such as information and knowledge. The main goal of data mining is the search for relationships and distinct patterns that exist in datasets but they are "hidden" among the vast amount of data. Data mining...
Chapter
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Courseware construction is always a hard task. A useful guide for courseware authors would be an assessment procedure with continuous evaluation after the usage of the content of the courseware. This procedure has to be iterative, in order to keep authors up to date with the efficiency of their courses. This paper proposes a method which is based o...
Article
Full-text available
This paper presents an adaptive load balancing algorithm (ALBL) for cluster-based web systems. The balancing policy is based on two criteria: HTTP process time and network delay. The former describes web server ability to process a forthcoming request, while the latter tries to estimate network conditions. Periodic criteria calculations are perform...
Article
Full-text available
Learning Greek as a second or foreign language has drawn the attention of many researchers throughout time. A dictionary is amongst the first things a foreign language student uses. Reading comprehension is significantly improved by the use of a dictionary, especially when this includes the way words are pronounced. We developed a assistance softwa...
Conference Paper
The quality and the quantity of the e-Learning educational content is reflected by its usage. In this paper, old and new performance metrics and a simple performance prediction algorithm, for the measurement of both educational content as exposed by the educators and the usage of such educational material by the learners, are presented. Metrics and...
Conference Paper
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Educational content quality and quantity is a crucial factor for the success of e-learning procedure. This study puts forward a proposal that enables the evaluation of online content and its usage by the learners. It proposes some new measures and metrics for content and course usage and investigates, through data mining techniques, the impact of u...
Article
Full-text available
In Adaptive Educational Hypermedia Systems (AEHS), we expect that the learning content presentation should be appropriately retrieved from learning object repositories, and dynamically tailored to each learner's needs. Each learner has a profile, subject to continuous change. The basic components of the learner's profile include his/her cognitive c...
Article
We propose a method for DDoS detection by constructing a fuzzy estimator on the mean packet inter arrival times. We divided the problem into two challenges, the first being the actual detection of the DDoS event taking place and the second being the identification of the offending IP addresses. We have imposed strict real time constraints for the f...
Article
Full-text available
Learning management systems (LMSs) are software tools designed to manage user learning interventions. On the other hand, in most LMSs there are neither appropriate metrics nor algorithms embedded in them which would facilitate their qualitative and quantitative measurement. The purpose of this paper is to use existing techniques in a different way,...
Article
Full-text available
Learning Management Systems (LMS) collect large amounts of data. Data mining techniques can be applied to analyse their web data log files. The instructors may use this data for assessing and measuring their courses. In this respect, we have proposed a methodology for analysing LMS courses and students' activity. This methodology uses a Markov CLus...
Article
Full-text available
The usage of web applications can be measured with the use of metrics. In a LMS, a typical web application, there are no appropriate metrics which would facilitate their qualitative and quantitative measurement. The purpose of this paper is to propose the use of existing techniques with a different way, in order to analyze the log file of a typical...
Conference Paper
Full-text available
In this paper authors present a new open source SNMP manager application called SETH. This application includes the following major attributes over existing management tools: MIB file parsing capabilities, automatic discovery of network topology and variable up to real-time probing frequency of network equipment in order to extract useful statistic...
Conference Paper
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LMS are used more and more nowadays. There are some algorithms for LMS usage assessment. The main problem is that these algorithms are rarely combined. This gap can be filled by using S-Algo which combines ranking and suggestion results of two or more suggestion/ranking algorithms into an ultimate and efficient ranking suggestion. Such efficient ra...
Article
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The rapid change of computers from isolated machines to networks and the need of people to exchange information lead us to the World Wide Web (WWW). Nowadays a lot of people are spending lot of hours in WWW searching information for every aspect of life. This increase of information in WWW, increase also the difficulty to find and access the inform...
Article
Full-text available
The aim of the present project is to record and investigate the beliefs, perceptions, attitudes and positions of the Electrical and Computer Engineering first year students of Democritus University of Thrace (DUTH) regarding computer programming. The data was analysed through implicative statistical analysis and CHIC software, which provided the fo...
Article
Full-text available
Further education and training are very important factors for the agriculture sector. Unfortunately, the lack of time and space has lead to their limited appliance to farmers. Limited financial support and low background knowledge in Information and Communications Technology are two more suspending factors. At the same time rapid technological prog...
Conference Paper
O ΛΟΚΛΗΡΩΜΕΝΟ ΠΛΗΡΟΦΟΡΙΑΚΟ ΣΥΣΤΗΜΑ ΥΠΟΛΟΓΙΣΜΟΥ ΤΗΣ ΑΝΤΙΚΕΙΜΕΝΙΚΗΣ ΑΞΙΑΣ ΚΑΙ ΕΚΚΑΘΑΡΙΣΗΣ ΤΟΥ ΦΟΡΟΥ ΜΕΤΑΒΙΒΑΣΗΣ ΑΚΙΝΗΤΟΥ G-TAXIS Geographic Tax Information System
Conference Paper
Full-text available
Earlier studies suggest that educational institutions may further benefit from Learning Management Systems (LMSs) by generating reports regarding courses. That is, with the use of tools focus to assess student's paths into course content. This paper affirms that educational meaningful information can be extracted from LMS student logged data and pr...
Conference Paper
Full-text available
This paper introduces new metrics for course evaluation. It is also proposes a ranking algorithm that classifies courses based on the previous course evaluation metrics and suggests appropriate actions for course content improvement. The algorithm was tested and verified successfully in data originated from the eClass platform of TEI Kavala.
Article
Full-text available
The aim of this study is to present our perspectives on healthcare analysis and design and the lessons learned from our experience with the development of a distributed, object-oriented Clinical Information System (CIS). In order to overcome known issues regarding development, implementation and finally acceptance of a CIS by the physicians we deci...
Conference Paper
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Conference Paper
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The World Wide Web hosts ever-increasing volumes of diverse data and associated services that cannot be fully exploited unless appropriate management and integration technologies are developed. To cover this need, the semantic Web was introduced as the second-generation WWW, enriched by machine-understandable data which supports the user in his tas...
Conference Paper
The continuous progress of the computer technology, the decrease of the dimensions and the power consumption that has taken place during the last decades, has enabled large computer companies to design new products that take advantage of the possibilities that the wireless networks offer. A very interesting implementation is indoor localization. Th...
Article
The progress of the computer technology, the decrease of the dimensions and the power consumption that has taken place during the last decades, has enabled large computer companies to design new products that take advantage of the possibilities that the wireless networks offer. A very interesting problem is indoor localization of a portable device....
Article
Full-text available
The aim of the present research is to find the factors, which define students' behaviors towards programming. The Analyze Factorielle des Correspondences (AFC) has been used which help to devise the people who answered in groups according to their attitudes. To apply the method variables were concluded, which referred to students' feelings towards...
Conference Paper
The increasing number of portable computers, combined with the requirement for non-stop connections to networks, makes the provision of Inter-net mobility important. Mobile IP defines protocols and procedures by which a mobile node can exchange packets, regardless of its current point-of-attachment to the Internet, and without changing its IP addre...
Article
Full-text available
An initial GIS data base has been assembled in 2001 covering the various parameters related to the Nestos river basin and its delta. This data set is being used for water resources modelling purposes within the frame of the multinational PROMENES initiative. The initial data gathering has produced a vast set of information which has been stored usi...
Article
“Transliteration” in linguistics means the system of conveying as nearly as possible by means of one set of letters or characters the pronunciation of the words in languages written and printed in a totally different script. This term may be applied to a transcription in Latin letters of Greek, Hebrew, or the Slavonic languages written in the Cyril...
Conference Paper
The increasing number of portable computers, combined with the requirement of non-stop connections to networks (Internet/Intranet), makes the provision of Internet mobility by Mobile IP important. The goal of Mobile IP protocol is to allow a Mobile host to send and receive packets, regardless of its current point of attachment to the Internet as we...
Article
ArtShow is a digital image database, which employs a number of sophisticated features for interactive presentations of the data included. The manipulation of the database is based on Microsoft Access, the user interface is set up on Macromedia Authorware, while additional features are programmed by Borland Delphi. The look and feel of the entire sy...
Article
The Greeks are between the hardest smokers in the whole world. In order to check the frequency of smoking between teenagers, we made a study among high school students in Kavala area. We prepared a multiple choice questionnaire, concerning questions about smoking in relation with student's life style and interests and also about smoking in their fa...
Conference Paper
The problem of 3D presentation in a window is treated. We describe the approach chosen. The mathematical background is quite simple. We develop a new library containing useful tools for 3D presentation based on the same mathematical theory. We not only create 3D objects with motion properties, but also a virtual environment. The theoretic camera of...
Article
The Kavala Health Heart Program is an intervention program aimed in reducing CVD factors in Kavala, Greece. The population of Kavala area is 135.000 and the deaths from CVD during 1984-91, are 20% higher than the CVD deaths of all Greece (332-402 per 100.000 or 270-290 per 100.000). This study was pinned to discover the most appropriate age of stud...
Article
Full-text available
Bottom is used in functional programming languages to denote abnormal situations. We propose the incorporation of this value in any existing imperative language. We show how this can be done and finally what are the benefits of the bottom incorporation in any imperative language.Covariant deep subtyping has always been viewed as a way to narrow the...
Article
A Pearson type III distribution model is used to simulate water distribution from rotating sprinklers. Using an analytical-numerical approach graphs were constructed for easy calculation of the performance parameters such as adequately irrigated area, mean deficit and deep percolation efficiency. In order to achieve this the coefficient of skewness...
Article
The consequences of social and economic disruption in the city of Thessaloniki following the large earthquake in 1978 are investigated. Specifically, the phenomenon of organized life in camps for Thessaloniki residents over a long period of time is studied. With the use of a questionnaire, all data regarding each person in the camps were assembled...
Conference Paper
Full-text available
In this paper we present a load balancing application for HTTP traffic that uses dynamic weights. We introduce a load balancing policy based on two criteria: “process time” and “network delay”. The former describes Web servers ability to process a forthcoming request, while the latter tries to estimate network conditions. Calculation of the two cri...
Technical Report
Full-text available
In this work, we present a case study of a secure mobile database application. In particular, we design, implement and evaluate a mobile database application for an electronic announcement board. We identify a set of security issues and apply appropriate techniques to sat-isfy the corresponding security requirements.
Article
Full-text available
The learner's Learning Style (LS) recognition has been proved a cornerstone to Adaptive Educational Hypermedia Systems' (AEHS) design. Like some of the other well known cognitive (and affective) taxonomies, the Kolb taxonomy illustrates a range of interrelated learning abilities and styles beneficial to novices and experts. As AEHSs designed to emp...
Article
Full-text available
We present an adaptive load balancing algorithm, ALBL, for cluster-based web systems. The balancing policy is based on two criteria; HTTP process time and network delay. The former describes web server ability to process a forthcoming request, while the latter tries to estimate network conditions. Periodic calculations of the criteria are performed...
Article
Full-text available
Purpose of this paper is to investigate on the next generation of data analysis tools. Multivari-ate Data Analysis refers to any statistical technique used to analyze data that arises from more than one variable. When available information is stored in database tables containing records and variables (rows and columns), Multivariate Analysis can be...
Article
Full-text available
This research was conducted in 2009 and reflects the business activity of the graduates from the TEI of Kavala. Aim of this research was to impress the particular characteristics of entrepreneurship activity of the graduates of Faculties of Business and Economics and Engineering, as well as to research the factors that are associated with the type...
Article
Η παρούσα έρευνα ασχολείται με τη μελέτη της διαχρονικής εξέλιξης της κατανομής της βιομηχανικής απασχόλησης και της απασχόλησης σε Υπηρεσίες στην Ελλάδα κατά τα τελευταία 30 χρόνια και βασίζεται σε στοιχεία των επίσημων απογραφών της ΕΣΥΕ των ετών 1968-1978-1988. Με τη βοήθεια των μεθόδων πολυδιάστατης ανάλυσης δεδομένων, παρακολουθούμε την εξέλιξ...
Article
Με την εργασία αυτή επιχειρείται ο εντοπισμός στη Βόρεια Ελλάδα των διαφοροποιήσεων (ανισοτήτων) μεταξύ των πολικών περιοχών και της υπόλοιπης Βόρειας Ελλάδας στον τομέα των υπηρεσιών, καθώς επίσης και ο προσδιορισμός των προβλημάτων που αφορούν στον τομέα των υπηρεσιών (οικονομικών-κοινωνικών κτλ) εντός των πολικών αυτών περιοχών. Η Θεσσαλονίκη ως...
Article
Βιβλιογραφία: σ. 38. Με την παρούσα εργασία γίνεται μια προσπάθεια μελέτης της περιφερειακής δομής της απασχόλησης στον δευτερογενή τομέα και βασικών κλάδων στον τριτογενή τομέα, με σκοπό τον προσδιορισμό χωρικών σχέσεων μεταξύ βιομηχανίας και υπηρεσιών. Κυρίως επιχειρείται ένας τρόπος αξιολόγησης και αξιοποίησης δύο μεθόδων της Ανάλυσης Δεδομένων...
Article
Full-text available
The aim of the present research is to find the factors, which define students' behaviors towards programming. The Analyze Factorielle des Correspondences (AFC) has been used which help to devise the people who answered in groups according to their attitudes. To apply the method variables were concluded, which referred to students' feelings towards...

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