Ciprian Zavoianu - weblog

Tips & Tricks: Handling expensive evaluation functions in Evolutionary Computation

2011-07-09T11:17:00.000+02:00

Evolutionary algorithms (EA) have become very popular for solving complex optimization / data based modeling problems as, generally, they are fairly robust, easy to use and able to produce high quality results. A common problem in real-word applications is the fact that the evaluation/fitness function employed by this type of algorithms is quite expensive (time-wise or even financially) to

Take the bus!

2011-06-22T10:48:00.003+02:00

Tips&Tricks: A little bit on personal information security - Tor and TrueCrypt

2011-05-30T20:34:00.008+02:00

In these most auspicious times for social networking, business cloud migration and setting trends on twitter about Justin Bieber, I'll try to draw a bit more attention towards two open-source, free, industry proven, high quality pieces of software that can help you add a little more privacy and security to your personal information (if for whatever conspiracy theory driven reason you would feel

Tips&Tricks: iWork Numbers - difference in minutes between two dates

2011-02-14T17:46:00.028+01:00

I can work with relative ease with Excel and OpenOffice Spreadsheet but the iWork Numbers application was totally new for me. I was working on a report in Numbers and I didn't know how to calculate the difference in minutes between two date fields and I must say that I didn't find the information I needed fast enough on the web. To keep the long story short, after 2-3 minutes of trial and error

My Master's Thesis

2010-12-05T17:45:00.028+01:00

As promised in my previous post regarding code bloating in GP, here is my Master's Thesis. Hopefully the version I've uploaded doesn't contain too many mistakes (scientific or language wise), but if you find any, please do let me know. You can download a close-to-final draft of the paper by clicking here or from my Downloads box (Zavoianu Ciprian - Master's Thesis.pdf). The same version of

Code Bloating in Genetic Programming

2010-11-20T14:49:00.033+01:00

In this post I'll try to present some information regarding the main subject of my Master's Thesis which is entitled "Towards Solution Parsimony in an Enhanced Genetic Programming Process" (sounds a bit bombastic, I know :P). Work on this paper has been carried out at the Heuristic and Evolutionary Algorithms Laboratory (HEAL) in the Hagenberg Softwarepark, Austria. My research was coordinated

Tips&Tricks: Two useful websites

2010-06-09T20:52:00.010+02:00

During work on my Master Thesis here in Austria I came across two very useful websites. The first one provides a very fast online plotting tool for 2D and 3D functions that allows the user to specify basic viewing options. The resulting images can be saved in various formats. Another very nice feature is the permalink option which basically allows users to share their plots with others.

My favourite quotes - revisited

2010-05-07T11:24:00.008+02:00

"Empty pockets never held anyone back. Only empty heads and empty hearts can do that" Norman Vincent Peale "A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new

Paper: On Sensor Data Simulation - SYNASC 2009

2010-03-24T10:08:00.032+01:00

I spent most of my time at the e-Austria Research Institute in Timişoara, Romania working with a team that was involved in the European FP7 Research Project DEHEMS. My main task was to design and implement a robust sensor simulation system. I worked on this task with my colleague, Ciprian Craciun, who's insight into the matter at hand and experience helped tremendously. . The resulting

Mini-project: Histograms R pretty cool - uni-dimensional binary classification example

2010-03-20T00:04:00.024+01:00

A few months ago I had to solve a pretty interesting, though not very difficult, assignment for my Machine Learning class. I really think that this is the very first lecture in any Machine Learning Class around the world. . So, given a data set containing 4 distinct features and 2 possible outcomes (or classes, noted for simplicity with -1 and +1) the task was to determine if any of the 4

Mini-project: Basic Systolic Algorithms

2009-10-30T13:57:00.094+01:00

Here are two very basic simulation applications for two systolic algorithms (aka. Instruction Systolic Arrays). Their main purpose is to illustrate how such systolic algorithms work on a given data set. Both simulators have been designed for the Systolic Algorithms course I've attended at my university. Application no.1: Systolic Array Sorting The first algorithm I have implemented aims to

Mini-project: DCrypt

2009-06-14T14:39:00.029+02:00

DCrypt is a small program I wrote for my network security class. It features 2 encryption ciphers and the DES algorithm. It was written in Delphi and allows for text to hexadecimal encryption and hexadecimal to text decryption. . The first cipher I included in DCrypt is the Viginere cipher. You can find out detailed information about this encryption method here. In this implementation, the cipher

Tips&Tricks: Meet Wordle

2009-02-08T20:42:00.020+01:00

For someone who's main field of interest is IT , I must shamefully admit that there are still very cool programs out there that, though eluded my attention :)), are well known by almost all of my friends. One such program is Wordle created by Jonathan Feinberg. Wordle is basically a toy for generating "word clouds" from given input text. In these clouds, greater prominence is given to the words

Mini-Project: Shutdown Timer

2009-02-01T21:39:00.029+01:00

Lately I got used to falling asleep while watching TV on my laptop and as my TV-tuner software is quite primitive and doesn't have the option to shutdown the computer after a predefined period of time, I started to search the web for a simple shutdown timer application. I didn't want a fancy application with a lot of options just a basic program that will enable me to select a period of time

Project: Bandwidth reduction

2009-01-19T09:10:00.030+01:00

This post is a follow-up to the problem of bandwidth reduction presented earlier. I've done a small Delphi application that can generate sparse matrices of various sizes and densities (the density of a sparse matrix is the percent of non-zero elements is contains) and that features 3 (actually more like 2 :)) ) bandwidth reduction algorithms. The first algorithm is the original Cuthill-McKee

Tutorial: Bandwidth reduction - The CutHill-McKee Algorithm

2009-01-15T10:48:00.116+01:00

1. The problem I've recently come across an interesting NP-complete problem :D. It's the bandwidth reduction problem, also known in the field of sparse matrix applications as the bandwidth minimization problem (or BMP in short):For a given simetric sparse matrix, M(nxn), the problem is to reduce its bandwidth B by permuting rows and columns such as to move all the nonzero elements of M in a band

My Bachelor's Thesis

2008-12-19T10:56:00.032+01:00

I've finally got around to converting my Bachelor's Thesis to .PDF and uploading it. Unfortunately, it is entirely in Romanian. As I've previously stated its main focus is to describe a hybrid lightweight task scheduling algorithm based on metaheuristics like local search, tabu search and simulated annealing (an adaptation of the proposed algorithm for the university course timetabling problem

Science ... by the bucket load

2008-12-17T08:21:00.018+01:00

Yesterday I came across the SCImago Journal & Country Rank site. It contains a set of nice tools for ranking analyzing and comparing scientific indicators by country and/or by scientific field. The information is taken from the Scopus database. Here are some of the facts about Romania (and as a comparison ... let's say ... Poland). The range taken into consideration is 1996 - 2007. Romania

Project: AutomatedTimetable

2008-11-17T13:33:00.044+01:00

This project is the result of a university team-assignment me and my colleagues signed up for in the spring of 2008. The goal was to build an automated timetabling solution that would aid in the generation of our department's timetable. . The application had to implement the following features: - it should allow the user to specify the general planning context (the number of professors,

Project: DOthello

2008-11-09T09:45:00.047+01:00

DOthello is my implementation of the classic Othello (aka Reversi) board game. The starting point of the project was an AI lab assignment regarding game trees (minmax, alpha-beta pruning, etc). I've decided not only to implement these algorithms but also incorporate them into a fun and easy to use application. DOthello has a quick in-game save and load mechanism and the position of the game board