Archive for February, 2010

Message TCP channel for .NET

February 2, 2010

Recently, I had the task to develop a simple server / client application that should work over the Internet. The communication needs were very simple and I had to use as much as possible lightweight components. So, I had to develop a simple TCP server / client that would handle the communication. For simplicity’s sake I decided to serialize the messages transmitted to XML, although this could easily change to something less verbose and more efficient. A better alternative would be to use Google’s Protocol Buffers.

(more…)

Επισκόπηση Αισθητήρων για την Πρόληψη Δασικών Πυρκαγιών

February 2, 2010

Στο πλαίσιο του φοιτητικού διαγωνισμού xirafia.gr ανέπτυξα μία δικτυακή εφαρμογή για την παρουσίαση δεδομένων πάνω σε διαδραστικό χάρτη, μέσω αισθητήρων (θερμόμετρα, ανεμόμετρα, κλπ) που τοποθετούνται σε επιλεγμένα σημεία. Στόχος της εφαρμογής είναι η πρόληψη και η έγκαιρη αντιμετώπιση των δασικών πυρκαγιών.

Μπορείτε να δείτε μία παρουσίαση της εφαρμογής εδώ:

http://docs.google.com/present/view?id=dfrqz4pd_51g7bssjg3

Μπορείτε να δείτε επίδειξη της λειτουργίας της εφαρμογής εδώ:

http://labpower.teipir.gr:1234/

Urban transportation systems and Voronoi diagrams

February 2, 2010

One crucial factor for most urban transportation systems (suburban railway, etc) is the positioning of the stations. It is desirable to cover an area as efficiently as possible. One way to measure the efficiency of the positioning of existing or new stations is to use a Voronoi diagram. The Voronoi diagram decomposes the city map into polygonal areas each one “served” by a specific station.

You can take a look at a live demonstration of the application featuring the railway system of Athens:

http://labpower.teipir.gr/prekageo/metro_map/

Reverse Server – A utility to bypass firewalls

February 2, 2010

You may find yourself in a situation that you want to access an SSH server which is located behind a firewall. The usual case would be to open port 22 so that you can connect to your server remotelly with your SSH client. There is, though, the possibility that you do not have access to the firewall rules or you are not allowed to change them. There is a workaround for this problem.

(more…)