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Official webpage


Fredrik Sandin,
Luleå tekniska universitet,
971 87 Luleå,

Publications with Bibtex

Profile at Google Scholar

Shellmap (2009)


This simple program is a result of my interest for the art and science of fireworks.

Firework shells need a strong and fairly symmetric container. Modern shells are sometimes made of polymer because it reduces assembly time. Traditional shells are made of paper. The process typically starts with paper hemispheres, which are filled with composition and are then joined together. Thereafter the shell is pasted with several layers of craft paper. It is necessary to maintain uniform thickness and strength of the shell, otherwise the burst becomes asymmetric.

The basic problem is that paper is flat and a shell is spherical, so the paper must be cut in a way that allows it to stretch and adapt to the curvature of the shell. The idea behind this tool is to calculate what parts to remove from a paper, so that it can be pasted on a hemisphere. Papers cut in this way can be used also to make hemispheres, e.g., by pasting several layers together and pressing them in a mould with a hydraulic press. Below is an example of a map with five sections for a 60mm shell, which was produced with this tool.



A python program that calculates maps in PDF format is available here. It is released under the GPL license, which is available here.

You need Grace and Python to run this program.

License and terms of use

This is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.


Etherpad Latex scripts (github)
Femtolensing calculator
Random indexing
SSH-distributed calculations

Technical reports

TDP derivatives (extends Appendix E/F)
Fault detection in district energy systems
Intelligent Industrial Processes

Bulletin board

Mutex locked... :-)

Mon Sep 14, 2015
Dr. Vasaki Ponnusamy from Quest International University in Malaysia is visiting us for one month with support from STINT.

Mon Aug 31, 2015
Sergio visits EUSIPCO 2015 and presents our paper.

Wed May 27, 2015
Sergio Martin del Campo Barraza presents his licentiate thesis on autonomous sensor systems. Congratulations! Thanks to the opponent, Karl Skretting, for his helpful questions at the seminar.

Mon Apr 27, 2015
Participated at CapoCaccia, great event! Implemented a realtime Matlab / Mex interface (screenshot) for the DAVIS device and learned more about criticality and the ROLLS.

Fri Dec 12, 2014
Gunnar Öquist Fellow ceremony. A memorable day and a great and timely opportunity. More info here.

Thu Nov 13, 2014
Received an encouraging letter from the student union. Thank you for nominating me!

Fri Nov 7, 2014
Presenting our work on interoperability by learning at BICA 2014 in Boston.

Wed Oct 1, 2014
Blerim defends his Ph.D. thesis. Congrats! See also the news article.

Thu Jun 5, 2014
Workshop on bio-inspired computation, organized at UTP, Malaysia. Thanks to STINT, UTP and MMU for support.

Fri Apr 25, 2014
Ph.D. student Sergio Martin del Campo attends MLSS2014 and presents a poster.

News archive.

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