article published by the "Mobile Telephony and Telecommunications" magazine (February 1999).

• Cellular Structure of Mobile Networks
• Cellular Structure of Mobile Networks (magazine extract - Greek version)

a data analysis project that completed using "R/RStudio", designed to help us discover and explore a research question, using real data and statistical methods taught in "Data Analysis and Statistical Inference" on-line class offered by "Coursera" (https://www.coursera.org/course/statistics | February - April 2014).

• Data Analysis and Statistical Inference

"mini-projects" in "Python", serving to reinforce "interactive programming" concepts taught in "Introduction to Interactive Programming in Python" on-line class offered by "Coursera" (https://www.coursera.org/course/interactivepython | September - November 2014). This course was designed to be an introduction to the basics of programming in "Python" by building simple interactive applications. The primary method for learning the course material was to work through multiple "mini-projects" in "Python". These projects included building games such as "Pong", "Blackjack", and "Asteroids". Attention: a browser-based programming environment "CodeSkulptor" was developed that made developing interactive applications in "Python" simple (http://www.codeskulptor.org/). "CodeSkulptor" runs "Python" programs in the browser by clicking the upper left button. It runs in "Chrome 18+", "Firefox 11+", and "Safari 6+". Some features may work in other browsers, but full functionality should not be expected. It does NOT run in "Internet Explorer".

• Interactive Programming in Python

a "Rails" web application developed as part of the on-line class "Ruby on Rails: An Introduction" offered by "Coursera" (https://www.coursera.org/learn/ruby-on-rails-intro | February 2016), which provides web page access to "recipe" information served by "http://food2fork.com/api" through "JSON" and images. This course explored how to build web applications with the "Ruby on Rails" web application framework starting with the basics of the "Ruby" programming language and continued with more advanced topics, exploring also "object oriented" programming in "Ruby", and demonstrating how to perform "unit testing". Core concepts behind "Ruby on Rails", such as "CoC" (Convention Over Configuration) and "MVC" (Model-View-Controller) were introduced. The version control system called "Git" was presented as well that was used to deploy that "Ruby on Rails" application to "Heroku".

• Ruby on Rails

a web app written in "Java Script" that encodes a message string according to the "GSM default" or "UCS2" alphabet and displays the hex data-stream representation of the encoded message. In case of a "long" SMS, it also splits the "encoded" message and presents the encoded "user data" message parts along with the proper "UDH" fields. A utility developed in 2014, while working for "Persado" as a "Connectivity" engineer, for the purposes of troubleshooting in the area of "SMS/SMPP" messages.

• SMS Message Analyser

an "Android" app inspired by the "Museum of Modern Art" in New York developed as part of the on-line class "Programming Mobile Applications for Android Handheld Systems: # 1" offered by "Coursera" (https://www.coursera.org/course/androidpart1 | May – June 2015), which creates and displays a user interface, presents a menu and a dialogue, and that opens a link to an external website. This course introduced the design as well as implementation of "Android" applications for mobile devices, discussing the "Android Platform" and the "Android Development Environment" and understanding the components comprising the "Android Platform", i.e the basic components from which all "Android" applications are created.

• Programming Mobile Applications for Android Handheld Systems

developed as part of the MSc. in "Telecommunication and Information Systems" course work during 1997 - 98 academic year. The MSc. course was offered by the Electronic Systems Engineering department of the University of Essex.

• Erlang's Loss Formula
• Statistical Analysis of Experimental Data

Attention: The Applets start automatically (after few seconds). If they do not work properly, please consult the following notes, which illustrate guidelines on how to overcome possible "Applet Run-Time Exceptions": The projects have been implemented in Java. Due to Java's SunBox restrictions, the execution of an applet can be interrupted by run-time exceptions, e.g. during the construction of dialog boxes or accessing local files. In order to overcome such problems, a nice way is the four steps that follow.

• Download the Java Run-time Environment (JRE) from Sun's web site http://java.com/en/download/index.jsp
• Install JRE on your computer. JRE comes with a Java Plug-in.
• In case of error starting applet such as the following one: Application Blocked by Security Settings, open Java Control Panel and adjust Security levels or "just" add http://aristotelis-metsinis.github.io/ in Exception Site List allowing applet to run after the appropriate security prompt. For more information, please have a look at http://www.java.com/en/download/help/win_controlpanel.xml and http://www.java.com/en/download/help/jcp_security.xml
• In case of "IO security" exceptions (e.g. read permission) and assuming that you like to "load" a file that resides under your "home" directory, make use of the policytool application program, which can be found in JRE's /bin/ directory. Based on the "default" java.security configuration, which can be found in JRE's /lib/security/ directory, you may have to edit two "policy" files, one called java.policy and can be found in JRE's /lib/security/ directory (e.g. "C:\Program Files (x86)\Java\jre7\lib\security\java.policy") and the other called .java.policy and resides under the /user.home/ directory (e.g. "C:\Users\user.home\.java.policy"). So, use policytool to edit both of these files. Specifically, highlight the existing CodeBase <ALL> "policy" entry and press Edit Policy Entry button. A "dialog" box will be displayed. Press Add Permission button. Choose FilePermission (java.io.FilePermission), ALL FILES as the TargetName and read in the Actions field. In this way, applet will (hopefully) overcome any "IO security" exceptions. Press "OK" and "Done" buttons and "save" policy file. Note: you may have to run policytool as "administrator" in order to edit and save properly the "\lib\security\java.policy" file.
• Restart applet. The HTML source code of the applet's web page will invoke automatically the Java plug-in, overcoming the security exceptions.

In case that you do not find the above notes useful, please feel free to email me at aristotelis.metsinis@gmail.com. More details can be found in Sun's Java web site.