New project GCU.GR

icon_512Some time now I am on a new project. It is called “Greek CAD Users” and its a forum community with everything that has to do with CAD software, for Greeks. If you are Greek and enjoy working on CAD programs, or you want to ask something, do not hesitate and sign up now!


Air Quality Project (ver. 1)


Due to economic growth, the number of the cars used has increased in the resent years. This accompanies the degradation of air quality, especially in industrialized countries and urban environments due to traffic congestion [1]. In many areas, the traffic related air pollution is the main reason of air quality degradation. The pollutant concentrations are related directly with the duration of the congestion [2]. The World Health Organization (2010)[3] has set the maximum values of pollutant concentrations but in many measurements, these values are exceeded[4].

 The concept

The concept is to build a low-cost, low power consuming device to monitor the quality of air. Continue reading

The use of neural networks in R with neuralnet package.

As the computing power grows the implementation of Artificial Neural Networks (ANN) becomes more and more common in computational systems and programs. Here it is explained what a simple feedforward artificial neural network is and how it is supposed to work.  This article is a demonstration about the R library neuralnet [1a,b] and how it can be applied. Continue reading

Image Editing Program with R (GUI)

R is not only for statistics. There is a big progress in packaging creation and there is a vast amount of libraries that let you do many things other than only statistics and data analysis. In this project it is demonstrated a GUI that lets the user make simple edits on photos. The edits user can do is to switch between GRB color mode and Grayscale, edit the Brightness of the image, the Contrast and the Gamma.  I wouldn’t recommend using this script on large pictures that are several megabytes because it makes the system crash. Continue reading

Handle or create a phone contacts file (“.vcf” format version 3.0[1])

I thought of this project in order to convert some of my  phone’s contact numbers from their national format (the one with the 00 in front of the number) to the one that the local providers recognize.

It was a bit challenging as it had to do with things like seeking from information inside data frames, converting data frames, applying changes, save data frames the way user wants etc. Some new aspects also stood on the way. Some of them I cannot figure, until this point, how to solve them.

The program is very different in its final form than it was thought first to be.  Continue reading

Importing a .csv file with data and using SQL commands to select the data we want and then plot them.

The program imports data in .csv format. It uses SQL SELECT command with two arguments, it asks the user if it is needed to group some of the data so it may use the COUNT and GROUP BY commands. After the new tables are created, it plots the data and prompts the user to give name to the plot and data.frame so they will be exported as jpeg and .csv respectively.  At the end it asks if there are data that are not numeric so it plots a bar chart instead of line plot. Continue reading